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TDMS Study 05150-01 Pathology Tables

NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97
Route: DOSED FEED                                                                                                 Time: 15:19:40




       Facility:  TSI Mason Research

       Chemical CAS #:  298-59-9

       Lock Date:  02/06/92

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































Note:  Animals arranged according to CID number

                                                              Page   1

NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 7| 4| 7| 4| 7| 7| 7| 2| 6| 7| 7| 2| 6| 7| 6| 5| 4| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 8| 8| 4| 4| 6| 4| 5| 2| 4| 4| 8| 4| 4| 4| 8| 7| 4| 8| 6| 6| 4| 4| 4| 4| 6|             
                                           | 2| 2| 8| 6| 3| 8| 0| 9| 8| 8| 1| 8| 8| 8| 2| 7| 8| 0| 3| 4| 8| 8| 8| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Sarcoma Stromal, Metastatic, Uterus  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X           X                           |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                       +                  |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Benign              |                         X                                                |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X           X     X     X  X              X        X  X  X     X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                                                          |             
      C-Cell, Carcinoma                    |                                                                X         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 7| 4| 7| 4| 7| 7| 7| 2| 6| 7| 7| 2| 6| 7| 6| 5| 4| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 8| 8| 4| 4| 6| 4| 5| 2| 4| 4| 8| 4| 4| 4| 8| 7| 4| 8| 6| 6| 4| 4| 4| 4| 6|             
                                           | 2| 2| 8| 6| 3| 8| 0| 9| 8| 8| 1| 8| 8| 8| 2| 7| 8| 0| 3| 4| 8| 8| 8| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Granulosa Cell Tumor Benign          |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp Stromal                        |                                        X        X                 X      |             
      Sarcoma Stromal                      |                                                       X                  |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                  +           +                           |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                  X                                       |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                  X                                       |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X                                       |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                       X                  |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X           X                           |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                                                          |             
      Fibroadenoma                         |          X                 X                       X           X     X   |             
      Fibroadenoma, Multiple               |                                                             X            |             
      Fibrosarcoma                         |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Trichoepithelioma                    |                   X                                                      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 7| 4| 7| 4| 7| 7| 7| 2| 6| 7| 7| 2| 6| 7| 6| 5| 4| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 8| 8| 4| 4| 6| 4| 5| 2| 4| 4| 8| 4| 4| 4| 8| 7| 4| 8| 6| 6| 4| 4| 4| 4| 6|             
                                           | 2| 2| 8| 6| 3| 8| 0| 9| 8| 8| 1| 8| 8| 8| 2| 7| 8| 0| 3| 4| 8| 8| 8| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X           X                           |             
      Squamous Cell Carcinoma, Metastatic, |                                                                          |             
           Ear                             |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
      Squamous Cell Carcinoma, Metastatic, |                                                                          |             
           Ear                             |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                         +                                                |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X           X           X                           |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 4| 4| 7| 7| 2| 6| 2| 7| 7| 4| 6| 7| 7| 7| 4| 6| 2| 5| 7| 2| 7| 7|             
                             DAY ON TEST   | 6| 6| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 6| 6| 2| 4| 4| 6| 6| 8| 5| 4| 6| 4| 4|             
                                           | 3| 3| 7| 3| 4| 7| 7| 2| 0| 1| 7| 7| 3| 0| 8| 7| 7| 3| 2| 1| 1| 7| 0| 7| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X           X                    X              X                  |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                +                                 |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Benign              |                                  X                                       |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |             X           X                 X     X     X     X  X     X  X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                     X        X                           |             
      C-Cell, Carcinoma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                X                                                         |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   5                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 4| 4| 7| 7| 2| 6| 2| 7| 7| 4| 6| 7| 7| 7| 4| 6| 2| 5| 7| 2| 7| 7|             
                             DAY ON TEST   | 6| 6| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 6| 6| 2| 4| 4| 6| 6| 8| 5| 4| 6| 4| 4|             
                                           | 3| 3| 7| 3| 4| 7| 7| 2| 0| 1| 7| 7| 3| 0| 8| 7| 7| 3| 2| 1| 1| 7| 0| 7| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Granulosa Cell Tumor Benign          |                                                                          |             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp Stromal                        |                                  X                                       |             
      Sarcoma Stromal                      |                                                             X            |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                        +              +                  |             
      Lumbar, Leukemia Mononuclear         |                                                       X                  |             
      Mediastinal, Leukemia Mononuclear    |                                        X              X                  |             
      Pancreatic, Leukemia Mononuclear     |                                        X                                 |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                                X              X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                                X              X                  |             
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X           X                    X              X                  |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                                                      X   |             
      Fibroadenoma                         |                X  X                       X                              |             
      Fibroadenoma, Multiple               |                               X                 X                        |             
      Fibrosarcoma                         |                                                 X                        |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Trichoepithelioma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +                                                                  |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   6                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 4| 4| 7| 7| 2| 6| 2| 7| 7| 4| 6| 7| 7| 7| 4| 6| 2| 5| 7| 2| 7| 7|             
                             DAY ON TEST   | 6| 6| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 6| 6| 2| 4| 4| 6| 6| 8| 5| 4| 6| 4| 4|             
                                           | 3| 3| 7| 3| 4| 7| 7| 2| 0| 1| 7| 7| 3| 0| 8| 7| 7| 3| 2| 1| 1| 7| 0| 7| 7|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    0 PPM                                  | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                                X              X                  |             
      Squamous Cell Carcinoma, Metastatic, |                                                                          |             
           Ear                             |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
      Squamous Cell Carcinoma, Metastatic, |                                                                          |             
           Ear                             |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |    +                                                                     |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X           X                    X              X                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   7                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 6| 6| 5| 2| 7| 7| 6| 7| 7| 6| 6| 2| 7| 7| 7| 6| 2| 7| 7|              |            |
                             DAY ON TEST   | 6| 7| 1| 7| 8| 4| 4| 8| 4| 4| 5| 4| 8| 4| 4| 4| 6| 8| 4| 4|              |            |
                                           | 4| 5| 3| 5| 2| 7| 7| 4| 7| 7| 0| 9| 2| 7| 7| 7| 8| 1| 7| 7|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|              |     A      |
    0 PPM                                  | 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  66        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  66        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X           X        X  X     X                                 |         13 |
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                       +                  |   4        |
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                  X                                       |          1 |
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                  X                                       |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                  X                                       |          2 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Pheochromocytoma Benign              |                   X                                                      |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Pars Distalis, Adenoma               |                X  X     X  X  X        X     X  X     X                  |         28 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      C-Cell, Adenoma                      |                               X  X                                       |          4 |
      C-Cell, Carcinoma                    |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page   8                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 6| 6| 5| 2| 7| 7| 6| 7| 7| 6| 6| 2| 7| 7| 7| 6| 2| 7| 7|              |            |
                             DAY ON TEST   | 6| 7| 1| 7| 8| 4| 4| 8| 4| 4| 5| 4| 8| 4| 4| 4| 6| 8| 4| 4|              |            |
                                           | 4| 5| 3| 5| 2| 7| 7| 4| 7| 7| 0| 9| 2| 7| 7| 7| 8| 1| 7| 7|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|              |     A      |
    0 PPM                                  | 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  M  M  +  +  +  +  +  +  M  +  +  +  +  +               |  65        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Granulosa Cell Tumor Benign          |                               X                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Polyp Stromal                        |                                                 X                        |          5 |
      Sarcoma Stromal                      |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |    +                                                                     |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |       +                       +                                          |   2        |
      Leukemia Mononuclear                 |       X                       X                                          |          2 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X                                                               |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +  +           +        +                                          |   8        |
      Lumbar, Leukemia Mononuclear         |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |          X           X        X                                          |          6 |
      Pancreatic, Leukemia Mononuclear     |          X                    X                                          |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X           X        X  X                                       |          9 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X           X        X  X                                       |          9 |
      Sarcoma Stromal, Metastatic, Uterus  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X           X        X  X     X                                 |         13 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                                  X                                       |          3 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenocarcinoma                       |                                                                          |          1 |
      Fibroadenoma                         |                                                       X  X               |         10 |
      Fibroadenoma, Multiple               |                   X                       X                              |          5 |
      Fibrosarcoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Basal Cell Adenoma                   |                      X                                                   |          1 |
      Trichoepithelioma                    |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page   9                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 6| 6| 5| 2| 7| 7| 6| 7| 7| 6| 6| 2| 7| 7| 7| 6| 2| 7| 7|              |            |
                             DAY ON TEST   | 6| 7| 1| 7| 8| 4| 4| 8| 4| 4| 5| 4| 8| 4| 4| 4| 6| 8| 4| 4|              |            |
                                           | 4| 5| 3| 5| 2| 7| 7| 4| 7| 7| 0| 9| 2| 7| 7| 7| 8| 1| 7| 7|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|              |     A      |
    0 PPM                                  | 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X           X        X  X                                       |         11 |
      Squamous Cell Carcinoma, Metastatic, |                                                                          |            |
           Ear                             |    X                                                                     |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |    +                                                                     |   1        |
      Squamous Cell Carcinoma, Metastatic, |                                                                          |            |
           Ear                             |    X                                                                     |          1 |
                                            __________________________________________________________________________|____________|
   Eye                                     |       +                       +     +                                    |   3        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |    +                                                                     |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X           X        X  X     X                                 |         13 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  10                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 4| 7| 7| 7| 7| 2| 2| 4| 7| 4| 7|             
                             DAY ON TEST   | 2| 6| 5| 4| 1| 4| 4| 4| 4| 4| 8| 4| 6| 4| 6| 4| 4| 4| 2| 8| 8| 9| 4| 6| 4|             
                                           | 1| 3| 0| 3| 2| 3| 3| 3| 4| 3| 5| 3| 0| 3| 4| 1| 4| 4| 8| 1| 2| 4| 4| 4| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    100 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                            X                                             |             
      Leukemia Mononuclear                 |          X                 X  X                    X                    X|             
                                            __________________________________________________________________________|             
   Mesentery                               |          +                       +                                +      |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Squamous Cell Papilloma              |    X                                                                     |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                        X                                 |             
      Pheochromocytoma Benign              |                                                    X                     |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                      X  X                                                |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M|             
      Adenoma                              |                            X                                             |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               | X     X  X  X     X     X        X  X                 X                  |             
      Pars Distalis, Adenoma, Multiple     |                                                                   X      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                               X     X                                    |             
      C-Cell, Carcinoma                    |                                                    X                     |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  11                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 4| 7| 7| 7| 7| 2| 2| 4| 7| 4| 7|             
                             DAY ON TEST   | 2| 6| 5| 4| 1| 4| 4| 4| 4| 4| 8| 4| 6| 4| 6| 4| 4| 4| 2| 8| 8| 9| 4| 6| 4|             
                                           | 1| 3| 0| 3| 2| 3| 3| 3| 4| 3| 5| 3| 0| 3| 4| 1| 4| 4| 8| 1| 2| 4| 4| 4| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    100 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp Stromal                        | X        X                    X  X                             X         |             
      Sarcoma Stromal                      |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                            +  +                                         +|             
      Axillary, Leukemia Mononuclear       |                               X                                          |             
      Mediastinal, Leukemia Mononuclear    |                               X                                         X|             
      Pancreatic, Leukemia Mononuclear     |                            X                                             |             
      Renal, Leukemia Mononuclear          |                                                                         X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosarcoma, Metastatic, Skin       |                            X                                             |             
      Leukemia Mononuclear                 |                               X                    X                    X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                    X                    X|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                 X  X                    X                    X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                         X|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                  X                    X                  |             
      Fibroadenoma                         | X                    X  X              X     X                          X|             
      Fibroadenoma, Multiple               |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                    X                     |             
      Fibroma                              |                                        X                                 |             
      Fibrosarcoma                         |                            X                                             |             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Astrocytoma Malignant                |                                                    X                     |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  12                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 4| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 4| 7| 7| 7| 7| 2| 2| 4| 7| 4| 7|             
                             DAY ON TEST   | 2| 6| 5| 4| 1| 4| 4| 4| 4| 4| 8| 4| 6| 4| 6| 4| 4| 4| 2| 8| 8| 9| 4| 6| 4|             
                                           | 1| 3| 0| 3| 2| 3| 3| 3| 4| 3| 5| 3| 0| 3| 4| 1| 4| 4| 8| 1| 2| 4| 4| 4| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    100 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Alveolar/Bronchiolar Adenoma         |                X                                                         |             
      Carcinoma, Metastatic, Thyroid Gland |                                                                          |             
      Fibrosarcoma, Metastatic, Skin       |                            X                                             |             
      Leukemia Mononuclear                 |                               X                    X                    X|             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Medulla      |                                        X                                 |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                  +                                       |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                   +                                                      |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Renal Tubule, Adenoma                |                                           X                              |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                 X  X                    X                    X|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  13                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 2| 2| 4| 4| 7| 6| 6| 7| 7| 7| 2| 7| 7| 4| 7| 4| 4| 7| 6| 7| 2| 7|             
                             DAY ON TEST   | 8| 8| 4| 8| 8| 6| 6| 4| 7| 3| 2| 4| 4| 8| 4| 2| 6| 4| 6| 6| 4| 8| 4| 8| 4|             
                                           | 2| 1| 4| 2| 1| 4| 3| 4| 1| 2| 9| 3| 4| 2| 4| 0| 4| 4| 4| 4| 4| 1| 7| 1| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    100 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                                                                          |             
      Leukemia Mononuclear                 |       X                 X  X  X                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                      +        +        +                       +         |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Squamous Cell Papilloma              |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |       X                                            X                     |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |       X        X     X           X  X        X     X        X  X  X      |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                  X        X                              |             
      C-Cell, Carcinoma                    |                                                                   X      |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  14                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 2| 2| 4| 4| 7| 6| 6| 7| 7| 7| 2| 7| 7| 4| 7| 4| 4| 7| 6| 7| 2| 7|             
                             DAY ON TEST   | 8| 8| 4| 8| 8| 6| 6| 4| 7| 3| 2| 4| 4| 8| 4| 2| 6| 4| 6| 6| 4| 8| 4| 8| 4|             
                                           | 2| 1| 4| 2| 1| 4| 3| 4| 1| 2| 9| 3| 4| 2| 4| 0| 4| 4| 4| 4| 4| 1| 7| 1| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    100 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp Stromal                        |                            X              X                 X            |             
      Sarcoma Stromal                      |                                  X                                       |             
                                            __________________________________________________________________________|             
   Vagina                                  |                            +                                             |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X                                             |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                      +                                                   |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
      Renal, Leukemia Mononuclear          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosarcoma, Metastatic, Skin       |                                                                          |             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                               X                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                 X  X  X                    X                     |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                     X                                    |             
      Fibroadenoma                         |                                           X  X                    X      |             
      Fibroadenoma, Multiple               |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Fibroma                              |       X                                                                  |             
      Fibrosarcoma                         |                                                                          |             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +                                                                  |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Astrocytoma Malignant                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  15                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 2| 2| 4| 4| 7| 6| 6| 7| 7| 7| 2| 7| 7| 4| 7| 4| 4| 7| 6| 7| 2| 7|             
                             DAY ON TEST   | 8| 8| 4| 8| 8| 6| 6| 4| 7| 3| 2| 4| 4| 8| 4| 2| 6| 4| 6| 6| 4| 8| 4| 8| 4|             
                                           | 2| 1| 4| 2| 1| 4| 3| 4| 1| 2| 9| 3| 4| 2| 4| 0| 4| 4| 4| 4| 4| 1| 7| 1| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    100 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Alveolar/Bronchiolar Adenoma         |                   X                                                      |             
      Carcinoma, Metastatic, Thyroid Gland |                                                                   X      |             
      Fibrosarcoma, Metastatic, Skin       |                                                                          |             
      Leukemia Mononuclear                 |                         X  X  X                                          |             
      Pheochromocytoma Malignant,          |                                                                          |             
          Metastatic, Adrenal Medulla      |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Renal Tubule, Adenoma                |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                 X  X  X                    X                     |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  16                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 6| 7| 7| 4| 4| 2| 7| 7| 7| 7| 5| 7| 6| 7|              |            |
                             DAY ON TEST   | 4| 6| 8| 4| 4| 4| 1| 4| 1| 6| 8| 8| 4| 4| 4| 4| 7| 4| 9| 1|              |            |
                                           | 4| 3| 2| 7| 7| 7| 9| 4| 3| 4| 8| 1| 7| 7| 7| 4| 9| 7| 9| 8|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|              |     A      |
    100 PPM                                | 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +               |  65        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +               |  66        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  A               |  63        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A               |  63        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Hepatocellular Adenoma               |                                                                          |          1 |
      Leukemia Mononuclear                 |                   X           X           X        X                     |         13 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   7        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Squamous Cell Papilloma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenoma                              |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  66        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Pars Distalis, Adenoma               |          X  X  X  X     X           X  X  X  X     X  X                  |         30 |
      Pars Distalis, Adenoma, Multiple     |                      X        X                                          |          3 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      C-Cell, Adenoma                      |          X     X                          X        X                     |          8 |
      C-Cell, Carcinoma                    |                                                                          |          2 |
      Follicular Cell, Adenoma             |                                              X                           |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  17                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 6| 7| 7| 4| 4| 2| 7| 7| 7| 7| 5| 7| 6| 7|              |            |
                             DAY ON TEST   | 4| 6| 8| 4| 4| 4| 1| 4| 1| 6| 8| 8| 4| 4| 4| 4| 7| 4| 9| 1|              |            |
                                           | 4| 3| 2| 7| 7| 7| 9| 4| 3| 4| 8| 1| 7| 7| 7| 4| 9| 7| 9| 8|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|              |     A      |
    100 PPM                                | 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Adenoma                              |                                                       X                  |          1 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Polyp Stromal                        |                                                          X               |          9 |
      Sarcoma Stromal                      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                           +              +               |   6        |
      Axillary, Leukemia Mononuclear       |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |                                                                          |          2 |
      Pancreatic, Leukemia Mononuclear     |                                           X                              |          2 |
      Renal, Leukemia Mononuclear          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Fibrosarcoma, Metastatic, Skin       |                                                                          |          1 |
      Leukemia Mononuclear                 |                   X           X           X                              |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                               X           X                              |          6 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                   X           X           X        X                     |         14 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenocarcinoma                       |                                                       X                  |          4 |
      Fibroadenoma                         |             X                          X  X                              |         12 |
      Fibroadenoma, Multiple               |          X                                                               |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Basal Cell Adenoma                   |                                                                          |          1 |
      Fibroma                              |                                                                          |          2 |
      Fibrosarcoma                         |                                                                          |          1 |
      Sarcoma                              |                                                 X                        |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  18                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 6| 7| 7| 4| 4| 2| 7| 7| 7| 7| 5| 7| 6| 7|              |            |
                             DAY ON TEST   | 4| 6| 8| 4| 4| 4| 1| 4| 1| 6| 8| 8| 4| 4| 4| 4| 7| 4| 9| 1|              |            |
                                           | 4| 3| 2| 7| 7| 7| 9| 4| 3| 4| 8| 1| 7| 7| 7| 4| 9| 7| 9| 8|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|              |     A      |
    100 PPM                                | 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Astrocytoma Malignant                |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Alveolar/Bronchiolar Adenoma         |                                     X                                    |          3 |
      Carcinoma, Metastatic, Thyroid Gland |                                                                          |          1 |
      Fibrosarcoma, Metastatic, Skin       |                                                                          |          1 |
      Leukemia Mononuclear                 |                   X           X                    X                     |          9 |
      Pheochromocytoma Malignant,          |                                                                          |            |
          Metastatic, Adrenal Medulla      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Renal Tubule, Adenoma                |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +               |  64        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                   X           X           X        X                     |         14 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  19                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 2| 4| 7| 4| 2| 5| 7| 7| 4| 4| 7| 7| 2| 4| 2| 7| 7| 6| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 2| 7| 8| 6| 4| 6| 8| 6| 4| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 8| 4| 4| 4| 4| 4|             
                                           | 5| 5| 1| 3| 2| 3| 1| 7| 2| 2| 3| 4| 2| 2| 2| 4| 1| 2| 2| 8| 2| 2| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                          X        X                                X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +                       +                 +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                                                             X            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                         X|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                                                                        |             
      Pars Distalis, Adenoma               |                      X  X                             X  X               |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
      Pars Distalis, Carcinoma             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                     X              X                     |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  20                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 2| 4| 7| 4| 2| 5| 7| 7| 4| 4| 7| 7| 2| 4| 2| 7| 7| 6| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 2| 7| 8| 6| 4| 6| 8| 6| 4| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 8| 4| 4| 4| 4| 4|             
                                           | 5| 5| 1| 3| 2| 3| 1| 7| 2| 2| 3| 4| 2| 2| 2| 4| 1| 2| 2| 8| 2| 2| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                      X                                                   |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma, Tubular                     |                            X                                             |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Polyp Stromal                        |                                              X     X              X      |             
      Sarcoma Stromal                      |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                      +                                      +            |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |    +                                                                     |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                        +                                 |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
      Renal, Leukemia Mononuclear          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                                                                    X   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                                                                    X   |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                          X        X                                X   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |             X                                                            |             
      Adenoma                              |                                                                          |             
      Fibroadenoma                         |                                                                   X      |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                             +            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  21                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 2| 4| 7| 4| 2| 5| 7| 7| 4| 4| 7| 7| 2| 4| 2| 7| 7| 6| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 2| 7| 8| 6| 4| 6| 8| 6| 4| 4| 6| 6| 4| 4| 8| 6| 8| 4| 4| 8| 4| 4| 4| 4| 4|             
                                           | 5| 5| 1| 3| 2| 3| 1| 7| 2| 2| 3| 4| 2| 2| 2| 4| 1| 2| 2| 8| 2| 2| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                          X                                         X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |    +                                                                     |             
      Carcinoma                            |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Lipoma                               |                         X                                                |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Papilloma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X                          X        X                                X   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  22                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 2| 2| 4| 7| 6| 2| 7| 7| 7| 7| 4| 7| 2| 5| 7| 6| 7| 7| 7| 5| 2|             
                             DAY ON TEST   | 4| 3| 6| 4| 8| 8| 6| 4| 7| 8| 4| 4| 4| 4| 6| 4| 8| 4| 4| 3| 4| 3| 4| 8| 8|             
                                           | 2| 0| 3| 2| 8| 1| 6| 2| 5| 2| 2| 2| 2| 2| 4| 3| 2| 6| 3| 8| 3| 0| 3| 8| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                          X  X        X  X      |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                       +  +  +  +         |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                             X                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                             X                  |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                                                |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                  +                                       |             
      Squamous Cell Papilloma              |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                     X                                    |             
      Pheochromocytoma Benign              |                                                    X                     |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                             X                  |             
      Pars Distalis, Adenoma               |       X              X        X              X                    X      |             
      Pars Distalis, Adenoma, Multiple     |          X                             X                    X            |             
      Pars Distalis, Carcinoma             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      | X        X                                                     X         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  23                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 2| 2| 4| 7| 6| 2| 7| 7| 7| 7| 4| 7| 2| 5| 7| 6| 7| 7| 7| 5| 2|             
                             DAY ON TEST   | 4| 3| 6| 4| 8| 8| 6| 4| 7| 8| 4| 4| 4| 4| 6| 4| 8| 4| 4| 3| 4| 3| 4| 8| 8|             
                                           | 2| 0| 3| 2| 8| 1| 6| 2| 5| 2| 2| 2| 2| 2| 4| 3| 2| 6| 3| 8| 3| 0| 3| 8| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
      Leukemia Mononuclear                 |                         X                             X                  |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma, Tubular                     |                                                                          |             
      Leukemia Mononuclear                 |                         X                             X                  |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                         X                             X                  |             
      Polyp Stromal                        |       X  X        X                       X                    X         |             
      Sarcoma Stromal                      |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                         +                                                |             
      Leukemia Mononuclear                 |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +                    +     +        +              +        +     +   |             
      Axillary, Leukemia Mononuclear       |                                                       X                  |             
      Lumbar, Leukemia Mononuclear         |                                                       X                  |             
      Mediastinal, Leukemia Mononuclear    |    X                    X                             X                  |             
      Pancreatic, Leukemia Mononuclear     |                                                                X         |             
      Renal, Leukemia Mononuclear          |                                                       X                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                          X  X        X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                          X  X                  |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                             X        X  X      |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                               X  X                  |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                                                          |             
      Adenoma                              |                                  X                                       |             
      Fibroadenoma                         |                      X                                X  X               |             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Sarcoma                              |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  24                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 2| 2| 4| 7| 6| 2| 7| 7| 7| 7| 4| 7| 2| 5| 7| 6| 7| 7| 7| 5| 2|             
                             DAY ON TEST   | 4| 3| 6| 4| 8| 8| 6| 4| 7| 8| 4| 4| 4| 4| 6| 4| 8| 4| 4| 3| 4| 3| 4| 8| 8|             
                                           | 2| 0| 3| 2| 8| 1| 6| 2| 5| 2| 2| 2| 2| 2| 4| 3| 2| 6| 3| 8| 3| 0| 3| 8| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    500 PPM                                | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                       +                  |             
      Leukemia Mononuclear                 |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                          X  X        X         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
      Lipoma                               |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Leukemia Mononuclear                 |                         X                                                |             
      Papilloma                            |                                     X                                    |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                    X                          X  X        X  X      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  25                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 7| 7| 4| 7| 7| 2| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 2| 6|              |            |
                             DAY ON TEST   | 4| 6| 4| 4| 6| 4| 4| 8| 6| 4| 4| 4| 4| 3| 4| 4| 4| 4| 8| 4|              |            |
                                           | 2| 4| 2| 2| 4| 3| 3| 2| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 1| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|              |     A      |
    500 PPM                                | 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X        X              X     X                                 |         14 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |          +                                                               |   9        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Squamous Cell Papilloma              |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Pheochromocytoma Malignant           |                                  X                                       |          2 |
      Pheochromocytoma Benign              |                            X                                             |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +               |  65        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                                                                          |          3 |
      Pars Distalis, Adenoma               | X        X     X  X     X        X                 X     X               |         17 |
      Pars Distalis, Adenoma, Multiple     |                                     X        X                           |          5 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  26                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 7| 7| 4| 7| 7| 2| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 2| 6|              |            |
                             DAY ON TEST   | 4| 6| 4| 4| 6| 4| 4| 8| 6| 4| 4| 4| 4| 3| 4| 4| 4| 4| 8| 4|              |            |
                                           | 2| 4| 2| 2| 4| 3| 3| 2| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 1| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|              |     A      |
    500 PPM                                | 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Pars Distalis, Carcinoma             |                                                 X                        |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      C-Cell, Adenoma                      |          X                                         X                     |          7 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenoma                              |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma, Tubular                     |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          2 |
      Polyp Stromal                        |             X  X                          X                              |         11 |
      Sarcoma Stromal                      |                                           X                              |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                           +                              |   4        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                        X                                 |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |    +     +        +                       +                              |  12        |
      Axillary, Leukemia Mononuclear       |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |                                                                          |          3 |
      Pancreatic, Leukemia Mononuclear     |          X                                                               |          2 |
      Renal, Leukemia Mononuclear          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                        X                                 |          8 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +               |  68        |
      Leukemia Mononuclear                 |                                                                          |          6 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X        X              X     X                                 |         13 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          3 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  27                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 7| 7| 4| 7| 7| 2| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 2| 6|              |            |
                             DAY ON TEST   | 4| 6| 4| 4| 6| 4| 4| 8| 6| 4| 4| 4| 4| 3| 4| 4| 4| 4| 8| 4|              |            |
                                           | 2| 4| 2| 2| 4| 3| 3| 2| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 1| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|              |     A      |
    500 PPM                                | 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  66        |
      Adenocarcinoma                       |                                                                          |          1 |
      Adenoma                              |                                                                          |          1 |
      Fibroadenoma                         |                   X                             X                        |          6 |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Sarcoma                              |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Carcinoma, Metastatic, Pituitary     |                                                                          |            |
          Gland                            |                                                 X                        |          1 |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X                             X                                 |         10 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   1        |
      Carcinoma                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Lipoma                               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Papilloma                            |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  28                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 7| 7| 4| 7| 7| 2| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 2| 6|              |            |
                             DAY ON TEST   | 4| 6| 4| 4| 6| 4| 4| 8| 6| 4| 4| 4| 4| 3| 4| 4| 4| 4| 8| 4|              |            |
                                           | 2| 4| 2| 2| 4| 3| 3| 2| 3| 3| 3| 3| 3| 9| 3| 3| 3| 3| 1| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|              |     A      |
    500 PPM                                | 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |          X        X              X     X                                 |         14 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  29                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 4| 4| 7| 2| 4| 7| 7| 7| 7| 7| 7| 7| 4| 4| 7| 7| 7| 7| 4| 4| 7| 7| 7|             
                             DAY ON TEST   | 6| 8| 6| 0| 4| 8| 4| 4| 4| 4| 4| 4| 4| 4| 6| 6| 3| 3| 3| 3| 6| 6| 4| 3| 4|             
                                           | 3| 2| 3| 4| 1| 1| 2| 1| 1| 1| 1| 1| 1| 1| 3| 3| 7| 7| 7| 7| 4| 4| 1| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X                                            X|             
                                            __________________________________________________________________________|             
   Mesentery                               |                                        +                                 |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                                     +                                    |             
      Squamous Cell Papilloma              |                                     X                                    |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pheochromocytoma Benign              |                      X                                   X               |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                         X|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  M  M  M  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X  X                 X                 X     X  X           X   |             
      Pars Distalis, Adenoma, Multiple     |                                        X                                 |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                                                      X   |             
      C-Cell, Carcinoma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  30                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 4| 4| 7| 2| 4| 7| 7| 7| 7| 7| 7| 7| 4| 4| 7| 7| 7| 7| 4| 4| 7| 7| 7|             
                             DAY ON TEST   | 6| 8| 6| 0| 4| 8| 4| 4| 4| 4| 4| 4| 4| 4| 6| 6| 3| 3| 3| 3| 6| 6| 4| 3| 4|             
                                           | 3| 2| 3| 4| 1| 1| 2| 1| 1| 1| 1| 1| 1| 1| 3| 3| 7| 7| 7| 7| 4| 4| 1| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leiomyoma                            |             X                                                            |             
      Polyp Stromal                        |                      X                                            X      |             
      Polyp Stromal, Two                   |                                                                          |             
      Sarcoma Stromal                      |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                +                                                         |             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X        X                                   X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                                                          |             
      Fibroadenoma                         |                                                 X                        |             
      Fibroadenoma, Multiple               |                                                    X                     |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Keratoacanthoma                      |                                              X                           |             
      Pinna, Neurofibroma                  |             X                                                            |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Osteosarcoma                         |                   X                                                      |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  31                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 4| 4| 7| 2| 4| 7| 7| 7| 7| 7| 7| 7| 4| 4| 7| 7| 7| 7| 4| 4| 7| 7| 7|             
                             DAY ON TEST   | 6| 8| 6| 0| 4| 8| 4| 4| 4| 4| 4| 4| 4| 4| 6| 6| 3| 3| 3| 3| 6| 6| 4| 3| 4|             
                                           | 3| 2| 3| 4| 1| 1| 2| 1| 1| 1| 1| 1| 1| 1| 3| 3| 7| 7| 7| 7| 4| 4| 1| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Renal Tubule, Adenoma                |                      X                                                   |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Papilloma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                            X        X                                   X|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  32                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 4| 4| 2| 5| 2| 7| 6| 2| 7| 7| 2| 7| 2| 2| 4| 7| 5| 2| 7|             
                             DAY ON TEST   | 4| 4| 4| 4| 4| 4| 6| 6| 8| 9| 8| 4| 5| 8| 4| 4| 8| 4| 8| 8| 6| 3| 5| 8| 4|             
                                           | 1| 1| 1| 1| 1| 2| 3| 3| 1| 1| 2| 2| 8| 2| 2| 2| 1| 1| 2| 2| 4| 8| 9| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              | X                                                                        |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Sarcoma                              |                                                                X         |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X        X                    X                                    |             
                                            __________________________________________________________________________|             
   Mesentery                               | +                                                                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pheochromocytoma Benign              |                                                                X         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                           X                              |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Pars Distalis, Adenoma               | X  X     X                 X     X           X     X           X         |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                                                          |             
      C-Cell, Carcinoma                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  33                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 4| 4| 2| 5| 2| 7| 6| 2| 7| 7| 2| 7| 2| 2| 4| 7| 5| 2| 7|             
                             DAY ON TEST   | 4| 4| 4| 4| 4| 4| 6| 6| 8| 9| 8| 4| 5| 8| 4| 4| 8| 4| 8| 8| 6| 3| 5| 8| 4|             
                                           | 1| 1| 1| 1| 1| 2| 3| 3| 1| 1| 2| 2| 8| 2| 2| 2| 1| 1| 2| 2| 4| 8| 9| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leiomyoma                            |                                                                          |             
      Polyp Stromal                        |                      X                                                   |             
      Polyp Stromal, Two                   |                                                             X            |             
      Sarcoma Stromal                      |                                                    X                     |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                     +        +     +     +     +         |             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X        X                                                         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X        X                    X                                    |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  M  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenocarcinoma                       |                                                                          |             
      Fibroadenoma                         |                                              X                    X      |             
      Fibroadenoma, Multiple               |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Pinna, Neurofibroma                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Osteosarcoma                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  34                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 4| 4| 2| 5| 2| 7| 6| 2| 7| 7| 2| 7| 2| 2| 4| 7| 5| 2| 7|             
                             DAY ON TEST   | 4| 4| 4| 4| 4| 4| 6| 6| 8| 9| 8| 4| 5| 8| 4| 4| 8| 4| 8| 8| 6| 3| 5| 8| 4|             
                                           | 1| 1| 1| 1| 1| 2| 3| 3| 1| 1| 2| 2| 8| 2| 2| 2| 1| 1| 2| 2| 4| 8| 9| 1| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X                                                                  |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                         +|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Renal Tubule, Adenoma                |                                              X                           |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Papilloma                            |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X        X                    X                                    |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  35                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 6| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 2| 6| 7| 7| 7|              |            |
                             DAY ON TEST   | 4| 6| 1| 4| 4| 4| 4| 3| 4| 1| 3| 4| 4| 7| 4| 8| 6| 4| 4| 4|              |            |
                                           | 1| 4| 9| 2| 2| 1| 2| 0| 1| 4| 7| 1| 1| 6| 1| 1| 9| 1| 1| 1|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|              |     A      |
    1000 PPM                               | 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Fibroma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +               |  68        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                                                 X                        |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +               |  68        |
      Sarcoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                X           X  X        X  X     X                        |         12 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                            +                                             |   3        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                               X                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Squamous Cell Papilloma              |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                        X                                 |          1 |
      Pheochromocytoma Benign              |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +               |  61        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +               |  67        |
      Pars Distalis, Adenoma               |       X  X  X              X        X     X        X                     |         22 |
      Pars Distalis, Adenoma, Multiple     |                X                                         X               |          3 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      C-Cell, Adenoma                      |          X  X                    X                                       |          4 |
      C-Cell, Carcinoma                    |                                        X                                 |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  36                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 6| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 2| 6| 7| 7| 7|              |            |
                             DAY ON TEST   | 4| 6| 1| 4| 4| 4| 4| 3| 4| 1| 3| 4| 4| 7| 4| 8| 6| 4| 4| 4|              |            |
                                           | 1| 4| 9| 2| 2| 1| 2| 0| 1| 4| 7| 1| 1| 6| 1| 1| 9| 1| 1| 1|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|              |     A      |
    1000 PPM                               | 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leiomyoma                            |                                                                          |          1 |
      Polyp Stromal                        |       X  X              X  X                             X               |          8 |
      Polyp Stromal, Two                   |                                                                          |          1 |
      Sarcoma Stromal                      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                     +                                    |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |                      +                                                   |   1        |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                               X                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                            +           +                                 |   8        |
      Mediastinal, Leukemia Mononuclear    |                            X           X                                 |          2 |
      Pancreatic, Leukemia Mononuclear     |                            X           X                                 |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                            X  X        X        X                        |          6 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                            X  X        X        X                        |          6 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                X           X  X        X  X     X                        |         13 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  65        |
      Leukemia Mononuclear                 |                            X  X        X        X                        |          4 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenocarcinoma                       |       X                                                                  |          1 |
      Fibroadenoma                         |                                                                          |          3 |
      Fibroadenoma, Multiple               |       X                                                                  |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Basal Cell Adenoma                   |                                  X                                       |          1 |
      Keratoacanthoma                      |                                                                          |          1 |
      Pinna, Neurofibroma                  |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Osteosarcoma                         |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  37                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 6| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 2| 6| 7| 7| 7|              |            |
                             DAY ON TEST   | 4| 6| 1| 4| 4| 4| 4| 3| 4| 1| 3| 4| 4| 7| 4| 8| 6| 4| 4| 4|              |            |
                                           | 1| 4| 9| 2| 2| 1| 2| 0| 1| 4| 7| 1| 1| 6| 1| 1| 9| 1| 1| 1|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|              |     A      |
    1000 PPM                               | 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|              |     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|              |            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                               +                                          |   1        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                               +                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                            X  X        X        X                        |          6 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     | +                             +                                          |   2        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         | +                                                                        |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                               X                                          |          1 |
      Renal Tubule, Adenoma                |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Papilloma                            |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                X           X  X        X  X     X                        |         13 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  38                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 6| 4| 7| 5| 4| 7| 2| 7| 6| 7| 5| 7| 7| 7| 4| 2| 2| 2| 3| 4| 6| 7| 7|             
                             DAY ON TEST   | 5| 3| 3| 6| 3| 2| 6| 3| 7| 3| 9| 1| 6| 1| 3| 3| 6| 7| 7| 7| 0| 6| 3| 3| 3|             
                                           | 9| 2| 2| 3| 6| 4| 2| 6| 6| 6| 5| 5| 6| 7| 6| 6| 2| 6| 6| 5| 4| 3| 9| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                 X                 X  X  X                    X  X  X|             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                                  +        +      |             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pheochromocytoma Malignant           |                                           X                              |             
      Pheochromocytoma Benign              |                               X                                   X  X  X|             
      Bilateral, Pheochromocytoma Benign   |             X        X                                                   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |             X                                   X                        |             
      Pars Distalis, Adenoma, Multiple     |                      X                                                   |             
      Pars Distalis, Carcinoma             |                                     X                                    |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |             X                                                            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  39                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 6| 4| 7| 5| 4| 7| 2| 7| 6| 7| 5| 7| 7| 7| 4| 2| 2| 2| 3| 4| 6| 7| 7|             
                             DAY ON TEST   | 5| 3| 3| 6| 3| 2| 6| 3| 7| 3| 9| 1| 6| 1| 3| 3| 6| 7| 7| 7| 0| 6| 3| 3| 3|             
                                           | 9| 2| 2| 3| 6| 4| 2| 6| 6| 6| 5| 5| 6| 7| 6| 6| 2| 6| 6| 5| 4| 3| 9| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                            X                                             |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
      Bilateral, Interstitial Cell, Adenoma|    X  X  X        X  X     X  X  X     X  X  X                 X  X  X  X|             
      Interstitial Cell, Adenoma           | X           X  X                                X                        |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                        X                                 |             
                                            __________________________________________________________________________|             
   Lymph Node                              |             +           +              +                          +  +   |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                        X                             X   |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
      Renal, Leukemia Mononuclear          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                   X     X                       X  X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                   X                             X  X|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangiosarcoma                      |             X                                                            |             
      Leukemia Mononuclear                 |    X                 X                 X  X  X                    X  X  X|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +  +  M  +  M  +  +  +  M  +  +  +  M  +  +  +  +  +  +  M  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M|             
      Fibroadenoma                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  40                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 6| 6| 4| 7| 5| 4| 7| 2| 7| 6| 7| 5| 7| 7| 7| 4| 2| 2| 2| 3| 4| 6| 7| 7|             
                             DAY ON TEST   | 5| 3| 3| 6| 3| 2| 6| 3| 7| 3| 9| 1| 6| 1| 3| 3| 6| 7| 7| 7| 0| 6| 3| 3| 3|             
                                           | 9| 2| 2| 3| 6| 4| 2| 6| 6| 6| 5| 5| 6| 7| 6| 6| 2| 6| 6| 5| 4| 3| 9| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              |                X                                                         |             
      Fibrosarcoma                         |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +                                                                  |             
      Mesothelioma Malignant               |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Leukemia Mononuclear                 |    X                                   X                             X  X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |             +                       +                                    |             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                     X                                    |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
      Sarcoma                              |                                                                   X      |             
                                            __________________________________________________________________________|             
   Ureter                                  |                                  +                                       |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                 X                 X  X  X                    X  X  X|             
      Mesothelioma Malignant               |       X                                                                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 2| 4| 7| 4| 7| 2| 3| 4| 7| 7| 7| 7| 5| 7| 4| 7| 7| 7| 7| 2| 6| 2| 7|             
                             DAY ON TEST   | 9| 3| 7| 6| 3| 6| 3| 7| 9| 6| 3| 3| 3| 3| 4| 3| 6| 3| 3| 3| 0| 7| 6| 7| 3|             
                                           | 8| 5| 6| 3| 5| 3| 5| 5| 1| 2| 5| 5| 5| 5| 9| 5| 3| 6| 6| 6| 1| 6| 5| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X                              |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X                              |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                   X      |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                    X  X  X  X  X           X  X     X     X|             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                       +                  |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                   X      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              | X                             X     X  X                    X            |             
      Bilateral, Pheochromocytoma Benign   |                                  X                 X              X      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                          X               |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  I  +  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               | X           X                          X              X                  |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
      Pars Distalis, Carcinoma             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                        X                                X|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  42                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 2| 4| 7| 4| 7| 2| 3| 4| 7| 7| 7| 7| 5| 7| 4| 7| 7| 7| 7| 2| 6| 2| 7|             
                             DAY ON TEST   | 9| 3| 7| 6| 3| 6| 3| 7| 9| 6| 3| 3| 3| 3| 4| 3| 6| 3| 3| 3| 0| 7| 6| 7| 3|             
                                           | 8| 5| 6| 3| 5| 3| 5| 5| 1| 2| 5| 5| 5| 5| 9| 5| 3| 6| 6| 6| 1| 6| 5| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      C-Cell, Carcinoma                    |             X                                                            |             
      Follicular Cell, Adenoma             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma| X  X        X  X  X        X  X  X  X     X  X     X  X  X  X     X     X|             
      Interstitial Cell, Adenoma           |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X                              |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                     +  +  +                 +     +      |             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                             X            |             
      Mediastinal, Leukemia Mononuclear    |                                           X                       X      |             
      Pancreatic, Leukemia Mononuclear     |                                           X                              |             
      Renal, Leukemia Mononuclear          |                                           X                 X            |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                     X  X  X                       X     X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X                       X     X|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangiosarcoma                      |                                                                          |             
      Leukemia Mononuclear                 |             X                    X  X  X  X  X           X  X     X     X|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  M  +  +  +  +  +  +  +  +  M  M  +  M  +  +  +  M  +  +  +  +  +  +|             
      Fibroadenoma                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  43                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 2| 4| 7| 4| 7| 2| 3| 4| 7| 7| 7| 7| 5| 7| 4| 7| 7| 7| 7| 2| 6| 2| 7|             
                             DAY ON TEST   | 9| 3| 7| 6| 3| 6| 3| 7| 9| 6| 3| 3| 3| 3| 4| 3| 6| 3| 3| 3| 0| 7| 6| 7| 3|             
                                           | 8| 5| 6| 3| 5| 3| 5| 5| 1| 2| 5| 5| 5| 5| 9| 5| 3| 6| 6| 6| 1| 6| 5| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              |                                                                          |             
      Fibrosarcoma                         |                                                          X               |             
      Keratoacanthoma                      |                                        X                                 |             
      Squamous Cell Papilloma              |                                                    X                     |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                X                                                         |             
      Leukemia Mononuclear                 |                                        X  X                 X     X     X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
      Carcinoma, Metastatic, Pituitary     |                                                                          |             
          Gland                            |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
      Sarcoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Ureter                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  +|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |             X                    X  X  X  X  X           X  X     X     X|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  44                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 2| 7| 5| 5| 7| 6| 4| 7| 7| 7| 7| 2| 6| 6| 7| 7| 6| 6| 7|              |            |
                             DAY ON TEST   | 6| 7| 3| 9| 5| 3| 7| 6| 3| 3| 3| 3| 7| 7| 1| 3| 3| 3| 7| 3|              |            |
                                           | 2| 5| 5| 4| 0| 5| 2| 2| 5| 5| 6| 6| 5| 7| 2| 6| 6| 5| 7| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     A      |
    0 PPM                                  | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  68        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +               |  65        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X  X     X        X     X     X  X  X     X  X                  |         29 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                         +     +                                          |   6        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |          X        X                                                      |          2 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  68        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |          X                                                               |          1 |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |                               X  X              X                        |         12 |
      Bilateral, Pheochromocytoma Benign   |                                                                          |          5 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  45                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 2| 7| 5| 5| 7| 6| 4| 7| 7| 7| 7| 2| 6| 6| 7| 7| 6| 6| 7|              |            |
                             DAY ON TEST   | 6| 7| 3| 9| 5| 3| 7| 6| 3| 3| 3| 3| 7| 7| 1| 3| 3| 3| 7| 3|              |            |
                                           | 2| 5| 5| 4| 0| 5| 2| 2| 5| 5| 6| 6| 5| 7| 2| 6| 6| 5| 7| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     A      |
    0 PPM                                  | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Pars Distalis, Adenoma               |       X                       X        X  X  X                           |         11 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          1 |
      Pars Distalis, Carcinoma             |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      C-Cell, Adenoma                      |                                              X                           |          4 |
      C-Cell, Carcinoma                    |                                                                          |          1 |
      Follicular Cell, Adenoma             |                                        X                                 |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                          X               |          2 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +               |  69        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  M  +  +               |  68        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          1 |
      Bilateral, Interstitial Cell, Adenoma| X     X  X  X  X  X  X  X  X  X  X     X  X  X  X  X  X  X               |         50 |
      Interstitial Cell, Adenoma           |                                                                          |          5 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                                        X                                 |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |          +                             +                                 |  12        |
      Axillary, Leukemia Mononuclear       |          X                                                               |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |          X                             X                                 |          6 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          1 |
      Renal, Leukemia Mononuclear          |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |          X  X                                      X                     |         13 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |       X  X  X     X              X     X     X     X                     |         15 |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  46                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 2| 7| 5| 5| 7| 6| 4| 7| 7| 7| 7| 2| 6| 6| 7| 7| 6| 6| 7|              |            |
                             DAY ON TEST   | 6| 7| 3| 9| 5| 3| 7| 6| 3| 3| 3| 3| 7| 7| 1| 3| 3| 3| 7| 3|              |            |
                                           | 2| 5| 5| 4| 0| 5| 2| 2| 5| 5| 6| 6| 5| 7| 2| 6| 6| 5| 7| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     A      |
    0 PPM                                  | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Hemangiosarcoma                      |                                           X                              |          2 |
      Leukemia Mononuclear                 |       X  X  X     X        X     X     X  X  X     X  X                  |         29 |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +               |  59        |
      Leukemia Mononuclear                 |          X                                                               |          2 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  M  M  +  +  +  M  +  +  M  +  +  +  +  +  M  +  +               |  57        |
      Fibroadenoma                         |                X                                                         |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Fibroma                              |                                                                          |          1 |
      Fibrosarcoma                         |                                                                          |          1 |
      Keratoacanthoma                      |                                                                          |          1 |
      Squamous Cell Papilloma              |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Mesothelioma Malignant               |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                    X                     |          1 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |          +                                                               |   1        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Alveolar/Bronchiolar Adenoma         |                               X                                          |          2 |
      Leukemia Mononuclear                 |          X  X     X              X     X  X        X                     |         16 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |          +                                                               |   3        |
      Carcinoma, Metastatic, Pituitary     |                                                                          |            |
          Gland                            |                                                                          |          1 |
      Leukemia Mononuclear                 |          X                                                               |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  47                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 2| 7| 5| 5| 7| 6| 4| 7| 7| 7| 7| 2| 6| 6| 7| 7| 6| 6| 7|              |            |
                             DAY ON TEST   | 6| 7| 3| 9| 5| 3| 7| 6| 3| 3| 3| 3| 7| 7| 1| 3| 3| 3| 7| 3|              |            |
                                           | 2| 5| 5| 4| 0| 5| 2| 2| 5| 5| 6| 6| 5| 7| 2| 6| 6| 5| 7| 6|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     A      |
    0 PPM                                  | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Mesothelioma Malignant               |                                                                          |          1 |
      Sarcoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Ureter                                  |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  M  +  +               |  63        |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |       X  X  X     X        X     X     X  X  X     X  X                  |         29 |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  48                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 3| 4| 4| 7| 7| 7| 7| 4| 2| 7| 7| 4| 7| 7| 7| 7| 2| 7| 6| 4| 7| 6|             
                             DAY ON TEST   | 7| 3| 3| 1| 6| 6| 3| 1| 3| 3| 6| 7| 3| 3| 6| 3| 3| 3| 3| 7| 3| 3| 2| 3| 7|             
                                           | 5| 4| 4| 5| 3| 2| 4| 7| 5| 4| 3| 5| 4| 4| 3| 4| 5| 4| 5| 6| 4| 9| 9| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    100 PPM                                | 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lipoma                               |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  A  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                                                                         X|             
      Leukemia Mononuclear                 |    X  X                    X           X              X        X        X|             
                                            __________________________________________________________________________|             
   Mesentery                               |                         +                                      +         |             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                X         |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                    +                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                X         |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                           X                              |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                            X                                             |             
      Pheochromocytoma Benign              |    X                    X                                               X|             
      Bilateral, Pheochromocytoma Benign   |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Pars Distalis, Adenoma               |       X        X        X                                               X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                   X                                         X            |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  49                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 3| 4| 4| 7| 7| 7| 7| 4| 2| 7| 7| 4| 7| 7| 7| 7| 2| 7| 6| 4| 7| 6|             
                             DAY ON TEST   | 7| 3| 3| 1| 6| 6| 3| 1| 3| 3| 6| 7| 3| 3| 6| 3| 3| 3| 3| 7| 3| 3| 2| 3| 7|             
                                           | 5| 4| 4| 5| 3| 2| 4| 7| 5| 4| 3| 5| 4| 4| 3| 4| 5| 4| 5| 6| 4| 9| 9| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    100 PPM                                | 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Interstitial Cell, Adenoma|    X  X     X     X     X  X        X  X     X  X  X  X     X  X  X  X  X|             
      Interstitial Cell, Adenoma           |                X     X        X           X                              |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                       X                  |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                         +  +                 +     +           +        +|             
      Mediastinal, Leukemia Mononuclear    |                            X                                   X        X|             
      Pancreatic, Leukemia Mononuclear     |                                                                         X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                  X        X        X|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                           X        X|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X                    X           X              X        X        X|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                X        X|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  M|             
      Fibroadenoma                         |                   X                                                      |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Fibroma                              |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  50                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 3| 4| 4| 7| 7| 7| 7| 4| 2| 7| 7| 4| 7| 7| 7| 7| 2| 7| 6| 4| 7| 6|             
                             DAY ON TEST   | 7| 3| 3| 1| 6| 6| 3| 1| 3| 3| 6| 7| 3| 3| 6| 3| 3| 3| 3| 7| 3| 3| 2| 3| 7|             
                                           | 5| 4| 4| 5| 3| 2| 4| 7| 5| 4| 3| 5| 4| 4| 3| 4| 5| 4| 5| 6| 4| 9| 9| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    100 PPM                                | 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                            X                                             |             
      Leukemia Mononuclear                 |    X                                                           X        X|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                        M                                 |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Renal Tubule, Adenoma                |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X                    X           X              X        X        X|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  51                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 2| 6| 6| 2| 7| 4| 2| 7| 7| 7| 4| 2| 7| 7| 4| 7| 4| 7| 4| 0| 7| 2| 7| 2|             
                             DAY ON TEST   | 5| 7| 7| 8| 7| 3| 6| 7| 3| 3| 3| 6| 7| 2| 3| 6| 3| 6| 3| 6| 4| 3| 7| 3| 7|             
                                           | 0| 6| 5| 7| 6| 4| 3| 6| 4| 4| 4| 3| 5| 4| 4| 3| 4| 3| 4| 2| 3| 4| 5| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    100 PPM                                | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lipoma                               |                X                                                         |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |                                                                          |             
      Leukemia Mononuclear                 | X     X  X              X  X  X        X        X              X     X   |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +        +                       +                              |             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X                                                               |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                            X  X                                          |             
      Bilateral, Pheochromocytoma Benign   |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            |                                                                      X   |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X                    X                 X                        |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                   X                                                      |             
      Follicular Cell, Carcinoma           |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  52                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 2| 6| 6| 2| 7| 4| 2| 7| 7| 7| 4| 2| 7| 7| 4| 7| 4| 7| 4| 0| 7| 2| 7| 2|             
                             DAY ON TEST   | 5| 7| 7| 8| 7| 3| 6| 7| 3| 3| 3| 6| 7| 2| 3| 6| 3| 6| 3| 6| 4| 3| 7| 3| 7|             
                                           | 0| 6| 5| 7| 6| 4| 3| 6| 4| 4| 4| 3| 5| 4| 4| 3| 4| 3| 4| 2| 3| 4| 5| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    100 PPM                                | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                              X                           |             
      Carcinoma                            |                X        X                                                |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Interstitial Cell, Adenoma| X              X  X     X  X  X  X     X  X  X  X  X  X  X     X     X   |             
      Interstitial Cell, Adenoma           |       X  X                                                               |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X  X                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +     +  +     +  +        +           +        +              +         |             
      Mediastinal, Leukemia Mononuclear    | X     X  X                             X                                 |             
      Pancreatic, Leukemia Mononuclear     | X        X                 X                    X                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X  X                 X                    X                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X  X                 X                    X                        |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X  X              X  X  X        X        X              X     X   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  M  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Fibroadenoma                         |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                 X                        |             
      Fibroma                              |                                                 X                        |             
      Keratoacanthoma                      |                            X                                             |             
      Sarcoma                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  53                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 2| 6| 6| 2| 7| 4| 2| 7| 7| 7| 4| 2| 7| 7| 4| 7| 4| 7| 4| 0| 7| 2| 7| 2|             
                             DAY ON TEST   | 5| 7| 7| 8| 7| 3| 6| 7| 3| 3| 3| 6| 7| 2| 3| 6| 3| 6| 3| 6| 4| 3| 7| 3| 7|             
                                           | 0| 6| 5| 7| 6| 4| 3| 6| 4| 4| 4| 3| 5| 4| 4| 3| 4| 3| 4| 2| 3| 4| 5| 4| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    100 PPM                                | 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Adenoma         |                                                                          |             
      Leukemia Mononuclear                 | X     X  X                                      X                        |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                +           +                                             |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |          X                                                               |             
      Renal Tubule, Adenoma                |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 | X     X  X              X  X  X        X        X              X     X   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  54                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 5| 6| 7| 7| 5| 6| 7| 4| 7| 6| 5| 7| 7| 4| 7| 7| 7| 7| 7|              |            |
                             DAY ON TEST   | 7| 3| 5| 3| 3| 4| 2| 3| 6| 3| 0| 9| 3| 3| 0| 3| 3| 3| 3| 3|              |            |
                                           | 6| 3| 0| 5| 5| 7| 3| 5| 2| 5| 0| 6| 5| 5| 9| 5| 5| 5| 5| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|              |     A      |
    100 PPM                                | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  +  +  +  +  A  +  +  A  +  +  +  +  +               |  64        |
      Lipoma                               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +               |  66        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  A  +  +  A  +  +  +  +  +  A  +  +  A  +  +  +  +  +               |  63        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Hepatocellular Adenoma               |                                                          X               |          2 |
      Leukemia Mononuclear                 |    X                          X              X  X  X  X  X               |         24 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                               +                    +                     |   7        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Pharynx                                 |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Pheochromocytoma Malignant           |                                                                          |          1 |
      Pheochromocytoma Benign              |                                                                          |          5 |
      Bilateral, Pheochromocytoma Benign   |             X                                                            |          1 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Carcinoma                            |                                  X                                       |          2 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +               |  66        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Pars Distalis, Adenoma               |             X  X     X                    X                              |         11 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  55                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 5| 6| 7| 7| 5| 6| 7| 4| 7| 6| 5| 7| 7| 4| 7| 7| 7| 7| 7|              |            |
                             DAY ON TEST   | 7| 3| 5| 3| 3| 4| 2| 3| 6| 3| 0| 9| 3| 3| 0| 3| 3| 3| 3| 3|              |            |
                                           | 6| 3| 0| 5| 5| 7| 3| 5| 2| 5| 0| 6| 5| 5| 9| 5| 5| 5| 5| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|              |     A      |
    100 PPM                                | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      C-Cell, Adenoma                      |                      X        X                                          |          5 |
      Follicular Cell, Carcinoma           |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
      Adenoma                              |             X                                                            |          2 |
      Carcinoma                            |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Bilateral, Interstitial Cell, Adenoma|    X     X  X     X  X  X  X  X  X  X  X     X        X  X               |         47 |
      Interstitial Cell, Adenoma           |                X                                X  X                     |          9 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |                               +                                          |   1        |
      Leukemia Mononuclear                 |                               X                                          |          1 |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |    X                          X                                          |          5 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |    +                          +                    +     +               |  19        |
      Mediastinal, Leukemia Mononuclear    |    X                          X                                          |          9 |
      Pancreatic, Leukemia Mononuclear     |    X                                               X                     |          7 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |    X                          X                                          |         11 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |    X                          X                    X     X               |         12 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |    X                          X        X     X  X  X  X  X               |         25 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +               |  67        |
      Leukemia Mononuclear                 |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  +  M  +  +  +  M  +  +  M  +  M  M  +  +  +  +  +  M  +               |  53        |
      Fibroadenoma                         |                                        X                                 |          2 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  56                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 5| 6| 7| 7| 5| 6| 7| 4| 7| 6| 5| 7| 7| 4| 7| 7| 7| 7| 7|              |            |
                             DAY ON TEST   | 7| 3| 5| 3| 3| 4| 2| 3| 6| 3| 0| 9| 3| 3| 0| 3| 3| 3| 3| 3|              |            |
                                           | 6| 3| 0| 5| 5| 7| 3| 5| 2| 5| 0| 6| 5| 5| 9| 5| 5| 5| 5| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|              |     A      |
    100 PPM                                | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Basal Cell Adenoma                   |                                                       X                  |          2 |
      Fibroma                              |                            X                    X                        |          3 |
      Keratoacanthoma                      |                                                                          |          1 |
      Sarcoma                              |                   X                                                      |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Alveolar/Bronchiolar Adenoma         |                                                                          |          1 |
      Leukemia Mononuclear                 |    X                          X                    X                     |         10 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                          +               |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |    X                                                                     |          2 |
      Renal Tubule, Adenoma                |                                                          X               |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  M  +  +  A  +  +  +  +  +  A  +  +  A  +  +  +  +  +               |  64        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |    X                          X        X     X  X  X  X  X               |         25 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  57                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 7| 7| 4| 7| 7| 7| 6| 3| 4| 3| 6| 7| 7| 4| 2| 7| 7| 4| 7| 7| 2| 7|             
                             DAY ON TEST   | 7| 3| 3| 3| 3| 6| 3| 3| 3| 5| 2| 6| 8| 2| 3| 3| 6| 7| 3| 3| 6| 0| 3| 7| 2|             
                                           | 5| 1| 1| 1| 1| 2| 1| 1| 1| 3| 5| 3| 3| 4| 1| 1| 3| 5| 4| 1| 3| 0| 1| 6| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  M  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  A|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X           X     X  X              X                    X         |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +           +        +              +           +                  |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
      Acinus, Adenoma                      |                      X                                                   |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |             X              X                          X                  |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                  X                                       |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Pars Distalis, Adenoma               |                      X                                                   |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Schwannoma Malignant, Metastatic,    |                                                                          |             
           Skin                            |                                                                          |             
      C-Cell, Adenoma                      |                   X                       X  X                           |             
      C-Cell, Carcinoma                    |       X                                      X                           |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  58                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 7| 7| 4| 7| 7| 7| 6| 3| 4| 3| 6| 7| 7| 4| 2| 7| 7| 4| 7| 7| 2| 7|             
                             DAY ON TEST   | 7| 3| 3| 3| 3| 6| 3| 3| 3| 5| 2| 6| 8| 2| 3| 3| 6| 7| 3| 3| 6| 0| 3| 7| 2|             
                                           | 5| 1| 1| 1| 1| 2| 1| 1| 1| 3| 5| 3| 3| 4| 1| 1| 3| 5| 4| 1| 3| 0| 1| 6| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                              X                           |             
      Carcinoma                            |                   X                                   X                  |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma|    X  X  X  X  X  X  X  X  X     X     X  X  X  X     X  X     X  X     X|             
      Interstitial Cell, Adenoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Osteosarcoma, Metastatic, Bone       |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +  +                 +  +              +        +           +        +|             
      Axillary, Leukemia Mononuclear       |                                                                          |             
      Lumbar, Leukemia Mononuclear         |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                            X                                   X         |             
      Pancreatic, Leukemia Mononuclear     |       X                                   X                              |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X                 X  X                                             |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X                 X  X                                   X         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X           X     X  X              X                    X         |             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  M  M  +  +|             
      Fibroadenoma                         |                         X                                                |             
                                            __________________________________________________________________________|             
   Skin                                    | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              |                                              X                           |             
      Keratoacanthoma                      |                            X                                             |             
      Sarcoma                              |                                                                          |             
      Squamous Cell Papilloma              |                                                                          |             
      Subcutaneous Tissue, Schwannoma      |                                                                          |             
          Malignant                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  59                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 7| 7| 7| 7| 4| 7| 7| 7| 6| 3| 4| 3| 6| 7| 7| 4| 2| 7| 7| 4| 7| 7| 2| 7|             
                             DAY ON TEST   | 7| 3| 3| 3| 3| 6| 3| 3| 3| 5| 2| 6| 8| 2| 3| 3| 6| 7| 3| 3| 6| 0| 3| 7| 2|             
                                           | 5| 1| 1| 1| 1| 2| 1| 1| 1| 3| 5| 3| 3| 4| 1| 1| 3| 5| 4| 1| 3| 0| 1| 6| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Chordoma                             |                                                                         X|             
      Osteosarcoma                         |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                         +|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                         +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |       X           X     X  X                                   X         |             
      Mesothelioma Malignant, Metastatic   |                                                                          |             
      Schwannoma Malignant, Metastatic,    |                                                                          |             
           Skin                            |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                     +                                    |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X  X           X     X  X              X                    X         |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  60                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 4| 7| 4| 7| 7| 7| 4| 5| 7| 7| 4| 6| 7| 7| 7| 2| 7| 6| 7| 4| 6| 6|             
                             DAY ON TEST   | 7| 7| 0| 0| 3| 6| 3| 3| 3| 6| 4| 3| 2| 6| 7| 3| 3| 3| 7| 3| 8| 3| 6| 3| 7|             
                                           | 5| 5| 1| 6| 1| 3| 1| 1| 1| 3| 2| 1| 2| 2| 4| 4| 4| 4| 6| 4| 1| 1| 2| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  A  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                          X  X        X  X        X|             
      Mesothelioma Malignant, Metastatic   |                      X                                                   |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +           +  +           +  +           +                       +|             
      Mesothelioma Malignant               |       X              X              X                                    |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                     X                                    |             
      Acinus, Adenoma                      |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Mesothelioma Malignant               |                                     X                                    |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                   X                                                      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X                        |             
      Pars Distalis, Adenoma               |                      X                                                   |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Schwannoma Malignant, Metastatic,    |                                                                          |             
           Skin                            |                                                                      X   |             
      C-Cell, Adenoma                      |                         X                                   X  X         |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Carcinoma           |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  61                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 4| 7| 4| 7| 7| 7| 4| 5| 7| 7| 4| 6| 7| 7| 7| 2| 7| 6| 7| 4| 6| 6|             
                             DAY ON TEST   | 7| 7| 0| 0| 3| 6| 3| 3| 3| 6| 4| 3| 2| 6| 7| 3| 3| 3| 7| 3| 8| 3| 6| 3| 7|             
                                           | 5| 5| 1| 6| 1| 3| 1| 1| 1| 3| 2| 1| 2| 2| 4| 4| 4| 4| 6| 4| 1| 1| 2| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X              X              X                                    |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                   X                                                      |             
      Carcinoma                            |                                  X                                       |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X              X                                                   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X                                                                  |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |       X              X              X                                    |             
      Bilateral, Interstitial Cell, Adenoma|       X     X  X  X     X  X     X  X  X  X  X  X  X     X  X  X  X  X  X|             
      Interstitial Cell, Adenoma           |                      X        X                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Osteosarcoma, Metastatic, Bone       |                                                             X            |             
                                            __________________________________________________________________________|             
   Lymph Node                              |       +     +                                +  +              +         |             
      Axillary, Leukemia Mononuclear       |                                                 X                        |             
      Lumbar, Leukemia Mononuclear         |                                                 X                        |             
      Mediastinal, Leukemia Mononuclear    |                                                 X              X         |             
      Pancreatic, Leukemia Mononuclear     |                                                                X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Leukemia Mononuclear                 |                                                 X              X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  M  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X  X        X  X         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                          X  X        X  X     X  X|             
      Mesothelioma Malignant               |       X                             X                                    |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  M  +  +  M  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +|             
      Fibroadenoma                         |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroma                              |                                                                          |             
      Keratoacanthoma                      |                                                                          |             
      Sarcoma                              |                               X                                          |             
      Squamous Cell Papilloma              |                                                                          |             
      Subcutaneous Tissue, Schwannoma      |                                                                          |             
          Malignant                        |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  62                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 2| 7| 4| 7| 4| 7| 7| 7| 4| 5| 7| 7| 4| 6| 7| 7| 7| 2| 7| 6| 7| 4| 6| 6|             
                             DAY ON TEST   | 7| 7| 0| 0| 3| 6| 3| 3| 3| 6| 4| 3| 2| 6| 7| 3| 3| 3| 7| 3| 8| 3| 6| 3| 7|             
                                           | 5| 5| 1| 6| 1| 3| 1| 1| 1| 3| 2| 1| 2| 2| 4| 4| 4| 4| 6| 4| 1| 1| 2| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    500 PPM                                | 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Chordoma                             |                                                                          |             
      Osteosarcoma                         |                                                             X            |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +              +              +                       +            |             
      Mesothelioma Malignant               |       X              X              X                                    |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X  X        X  X        X|             
      Mesothelioma Malignant, Metastatic   |       X                                                                  |             
      Schwannoma Malignant, Metastatic,    |                                                                          |             
           Skin                            |                                                                      X   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                                            +               |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |          +                                                               |             
      Carcinoma                            |          X                                                               |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  A  +  +  +  +  +  +  A  +  M  +  A  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                      X                          X  X        X  X     X  X|             
      Mesothelioma Malignant               |       X              X              X                                    |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  63                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 7| 4| 7| 6| 7| 7| 2| 2| 7| 7| 7| 7| 5| 2|              |            |
                             DAY ON TEST   | 3| 6| 7| 3| 3| 3| 3| 6| 3| 7| 3| 3| 7| 7| 3| 3| 3| 3| 6| 7|              |            |
                                           | 0| 2| 6| 1| 0| 0| 0| 2| 0| 7| 4| 4| 5| 6| 4| 1| 1| 1| 6| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    500 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  65        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  64        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  66        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  64        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  62        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X                 X                                             |         15 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                 +                                                      |  14        |
      Mesothelioma Malignant               |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  69        |
      Mesothelioma Malignant               |                                                                          |          1 |
      Acinus, Adenoma                      |                                           X                              |          2 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  68        |
      Mesothelioma Malignant               |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +               |  69        |
      Pheochromocytoma Malignant           |                               X                                          |          1 |
      Pheochromocytoma Benign              |                               X                                          |          5 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Pars Distalis, Adenoma               |             X           X        X        X     X                        |          7 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Schwannoma Malignant, Metastatic,    |                                                                          |            |
           Skin                            |                                                                          |          1 |
      C-Cell, Adenoma                      |                                                                          |          6 |
      C-Cell, Carcinoma                    |                                                                          |          2 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  64                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 7| 4| 7| 6| 7| 7| 2| 2| 7| 7| 7| 7| 5| 2|              |            |
                             DAY ON TEST   | 3| 6| 7| 3| 3| 3| 3| 6| 3| 7| 3| 3| 7| 7| 3| 3| 3| 3| 6| 7|              |            |
                                           | 0| 2| 6| 1| 0| 0| 0| 2| 0| 7| 4| 4| 5| 6| 4| 1| 1| 1| 6| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    500 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Follicular Cell, Carcinoma           |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                                          |          2 |
      Carcinoma                            |                         X                                                |          4 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Mesothelioma Malignant               |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          3 |
      Bilateral, Interstitial Cell, Adenoma| X        X  X     X  X  X  X     X        X  X  X  X  X                  |         51 |
      Interstitial Cell, Adenoma           |                X              X                                          |          4 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Osteosarcoma, Metastatic, Bone       |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                         +  +  +                                          |  16        |
      Axillary, Leukemia Mononuclear       |                                                                          |          1 |
      Lumbar, Leukemia Mononuclear         |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |                            X                                             |          5 |
      Pancreatic, Leukemia Mononuclear     |                                                                          |          3 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |                            X                                             |          6 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Leukemia Mononuclear                 |          X                 X                                             |         11 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X              X  X                                             |         17 |
      Mesothelioma Malignant               |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +               |  67        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  65                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 7| 4| 7| 6| 7| 7| 2| 2| 7| 7| 7| 7| 5| 2|              |            |
                             DAY ON TEST   | 3| 6| 7| 3| 3| 3| 3| 6| 3| 7| 3| 3| 7| 7| 3| 3| 3| 3| 6| 7|              |            |
                                           | 0| 2| 6| 1| 0| 0| 0| 2| 0| 7| 4| 4| 5| 6| 4| 1| 1| 1| 6| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    500 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  +  +  M  +  M  +  I  +  M  +  M  +  M  +  M  +  +  +  +               |  53        |
      Fibroadenoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Fibroma                              |                                                                          |          1 |
      Keratoacanthoma                      |                X  X                             X                        |          4 |
      Sarcoma                              |                                                                          |          1 |
      Squamous Cell Papilloma              |                                                 X                        |          1 |
      Subcutaneous Tissue, Schwannoma      |                                                                          |            |
          Malignant                        |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Chordoma                             |                                                                          |          1 |
      Osteosarcoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                   +                       +                              |   6        |
      Mesothelioma Malignant               |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |          X                 X                                             |         12 |
      Mesothelioma Malignant, Metastatic   |                                                                          |          1 |
      Schwannoma Malignant, Metastatic,    |                                                                          |            |
           Skin                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   3        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   1        |
      Carcinoma                            |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +               |  63        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  66                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 2| 7| 7| 7| 7| 4| 7| 6| 7| 7| 2| 2| 7| 7| 7| 7| 5| 2|              |            |
                             DAY ON TEST   | 3| 6| 7| 3| 3| 3| 3| 6| 3| 7| 3| 3| 7| 7| 3| 3| 3| 3| 6| 7|              |            |
                                           | 0| 2| 6| 1| 0| 0| 0| 2| 0| 7| 4| 4| 5| 6| 4| 1| 1| 1| 6| 5|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    500 PPM                                | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |          X              X  X                                             |         17 |
      Mesothelioma Malignant               |                                                                          |          3 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  67                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 5| 3| 7| 2| 7| 1| 4| 7| 2| 4| 7| 4| 7| 7| 4| 4| 6| 7| 4| 3| 7| 4| 4| 7|             
                             DAY ON TEST   | 5| 1| 8| 3| 7| 2| 8| 6| 2| 7| 6| 3| 3| 3| 3| 6| 6| 8| 3| 6| 5| 3| 6| 6| 3|             
                                           | 3| 8| 6| 0| 5| 9| 7| 3| 9| 6| 2| 0| 9| 0| 0| 2| 2| 2| 0| 2| 7| 0| 2| 2| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  A  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  A  +  +  +  A  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp                                |                                                                X         |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  A  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X     X     X        X                 X        X           X         |             
                                            __________________________________________________________________________|             
   Mesentery                               | +  +                                                  +                  |             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
      Acinus, Adenoma                      |                                                                         X|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                                           +                              |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
      Mesothelioma Malignant               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Benign              |                         X              X                       X        X|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
      Carcinoma                            |                                  X                                       |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X                       X           X                 X        X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, C-Cell, Adenoma           |                                                                X         |             
      C-Cell, Adenoma                      |          X     X                                                         |             
      C-Cell, Carcinoma                    |                                                                          |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  68                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 5| 3| 7| 2| 7| 1| 4| 7| 2| 4| 7| 4| 7| 7| 4| 4| 6| 7| 4| 3| 7| 4| 4| 7|             
                             DAY ON TEST   | 5| 1| 8| 3| 7| 2| 8| 6| 2| 7| 6| 3| 3| 3| 3| 6| 6| 8| 3| 6| 5| 3| 6| 6| 3|             
                                           | 3| 8| 6| 0| 5| 9| 7| 3| 9| 6| 2| 0| 9| 0| 0| 2| 2| 2| 0| 2| 7| 0| 2| 2| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                          |             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               | X                                                                        |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |    X                                                                     |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               | X                                                                        |             
      Bilateral, Interstitial Cell, Adenoma| X  X     X     X     X  X     X  X     X  X     X  X  X  X     X     X  X|             
      Interstitial Cell, Adenoma           |                                     X        X                    X      |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +                                +                          +         |             
      Mediastinal, Histiocytic Sarcoma     |                                     X                                    |             
      Mediastinal, Leukemia Mononuclear    |    X                                                           X         |             
      Pancreatic, Histiocytic Sarcoma      |                                     X                                    |             
      Pancreatic, Leukemia Mononuclear     |    X                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X           X        X                 X                    X         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X           X        X                 X        X                     |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X     X     X        X                 X        X           X         |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X           X                                                         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Fibroadenoma                         |                                        X                                 |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  69                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 5| 3| 7| 2| 7| 1| 4| 7| 2| 4| 7| 4| 7| 7| 4| 4| 6| 7| 4| 3| 7| 4| 4| 7|             
                             DAY ON TEST   | 5| 1| 8| 3| 7| 2| 8| 6| 2| 7| 6| 3| 3| 3| 3| 6| 6| 8| 3| 6| 5| 3| 6| 6| 3|             
                                           | 3| 8| 6| 0| 5| 9| 7| 3| 9| 6| 2| 0| 9| 0| 0| 2| 2| 2| 0| 2| 7| 0| 2| 2| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Fibroma                              |                         X                                                |             
      Keratoacanthoma                      |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X           X        X                          X           X         |             
      Mesothelioma Malignant, Metastatic,  |                                                                          |             
           Heart                           |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp                                |                                                                          |             
      Squamous Cell Carcinoma              | X                                                                        |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                  +                                       |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lipoma                               |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  A  A  +  +  +  A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|             
      Papilloma                            |                                                       X                  |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                     X                                    |             
      Leukemia Mononuclear                 |    X     X     X        X                 X        X           X         |             
      Mesothelioma Malignant               | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  70                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 1| 7| 7| 2| 6| 7| 7| 7| 7| 1| 6| 6| 5| 7| 4| 7| 7| 7| 6| 7| 4| 7| 7| 7|             
                             DAY ON TEST   | 7| 8| 2| 2| 7| 7| 3| 2| 2| 2| 8| 8| 7| 9| 3| 6| 2| 2| 2| 8| 3| 6| 2| 3| 3|             
                                           | 6| 5| 9| 9| 6| 8| 0| 9| 9| 9| 0| 6| 5| 8| 0| 3| 9| 9| 9| 2| 0| 3| 2| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Polyp                                |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |          X     X  X  X  X  X           X        X  X     X  X     X      |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                   +     +  +                    +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Acinus, Adenoma                      |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Mesothelioma Malignant               |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Benign              |          X                                            X        X        X|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                  X                    X                  |             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |                         X  X        X              X                     |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, C-Cell, Adenoma           |                                                                          |             
      C-Cell, Adenoma                      |       X  X                                                              X|             
      C-Cell, Carcinoma                    |                                           X                              |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  71                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 1| 7| 7| 2| 6| 7| 7| 7| 7| 1| 6| 6| 5| 7| 4| 7| 7| 7| 6| 7| 4| 7| 7| 7|             
                             DAY ON TEST   | 7| 8| 2| 2| 7| 7| 3| 2| 2| 2| 8| 8| 7| 9| 3| 6| 2| 2| 2| 8| 3| 6| 2| 3| 3|             
                                           | 6| 5| 9| 9| 6| 8| 0| 9| 9| 9| 0| 6| 5| 8| 0| 3| 9| 9| 9| 2| 0| 3| 2| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                  +                                       |             
      Adenoma                              |                                  X                                       |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                          |             
      Carcinoma                            |                                     X                             X      |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |                                                                          |             
      Bilateral, Interstitial Cell, Adenoma|       X  X     X  X  X  X  X     X     X  X  X  X  X  X  X  X  X  X  X  X|             
      Interstitial Cell, Adenoma           |             X                       X                                    |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                +                 +                                       |             
      Mediastinal, Histiocytic Sarcoma     |                                                                          |             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Histiocytic Sarcoma      |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                X                                                         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |          X     X     X     X                    X  X     X        X      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |                X  X  X     X           X        X  X     X  X     X      |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |          X     X  X  X  X  X           X        X  X     X  X     X      |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |                                                          X               |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  M  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +|             
      Fibroadenoma                         |                                           X                              |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  72                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 2| 1| 7| 7| 2| 6| 7| 7| 7| 7| 1| 6| 6| 5| 7| 4| 7| 7| 7| 6| 7| 4| 7| 7| 7|             
                             DAY ON TEST   | 7| 8| 2| 2| 7| 7| 3| 2| 2| 2| 8| 8| 7| 9| 3| 6| 2| 2| 2| 8| 3| 6| 2| 3| 3|             
                                           | 6| 5| 9| 9| 6| 8| 0| 9| 9| 9| 0| 6| 5| 8| 0| 3| 9| 9| 9| 2| 0| 3| 2| 0| 0|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1000 PPM                               | 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|             
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Fibroma                              |                      X                                                   |             
      Keratoacanthoma                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |                X  X                    X        X        X        X      |             
      Mesothelioma Malignant, Metastatic,  |                                                                          |             
           Heart                           |                                  X                                       |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Polyp                                |                                                                          |             
      Squamous Cell Carcinoma              |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                   +  +  +|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lipoma                               |                            X                                             |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Papilloma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |                                                                          |             
      Leukemia Mononuclear                 |          X     X  X  X  X  X           X        X  X     X  X     X      |             
      Mesothelioma Malignant               |                                  X                                       |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  73                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 4| 5| 2| 7| 2| 7| 7| 2| 6| 7| 7| 2| 7| 2| 7| 7|              |            |
                             DAY ON TEST   | 2| 2| 2| 2| 6| 9| 7| 2| 7| 2| 3| 7| 3| 3| 3| 7| 2| 7| 2| 2|              |            |
                                           | 9| 9| 9| 9| 2| 0| 5| 9| 5| 9| 0| 6| 9| 0| 0| 5| 9| 6| 9| 9|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    1000 PPM                               | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  66        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  63        |
      Polyp                                |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  65        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  64        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X                       X                                 |         23 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +  +     +           +              +                    +               |  14        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +               |  69        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Acinus, Adenoma                      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
      Mesothelioma Malignant               |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Pheochromocytoma Benign              |                                        X  X           X                  |         11 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +               |  69        |
      Adenoma                              |                                                                          |          2 |
      Carcinoma                            |                                                 X                        |          2 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  M  +  +  +  +  M  +  M  +  +  +  +  +  +  M  M  +  +  +               |  63        |
      Adenoma                              |                                                       X                  |          1 |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Pars Distalis, Adenoma               |       X                                   X                              |         11 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  74                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 4| 5| 2| 7| 2| 7| 7| 2| 6| 7| 7| 2| 7| 2| 7| 7|              |            |
                             DAY ON TEST   | 2| 2| 2| 2| 6| 9| 7| 2| 7| 2| 3| 7| 3| 3| 3| 7| 2| 7| 2| 2|              |            |
                                           | 9| 9| 9| 9| 2| 0| 5| 9| 5| 9| 0| 6| 9| 0| 0| 5| 9| 6| 9| 9|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    1000 PPM                               | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Bilateral, C-Cell, Adenoma           |                                                                          |          1 |
      C-Cell, Adenoma                      |             X                 X     X                                    |          8 |
      C-Cell, Carcinoma                    |                                                                          |          1 |
      Follicular Cell, Carcinoma           |                                                 X                        |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                          |   1        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Adenoma                              |                                                          X               |          1 |
      Carcinoma                            |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Mesothelioma Malignant               |                                                                          |          1 |
      Bilateral, Interstitial Cell, Adenoma| X  X  X  X  X  X     X        X     X  X  X     X     X  X               |         51 |
      Interstitial Cell, Adenoma           |                            X                                             |          6 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +                             +  +              +                  |  11        |
      Mediastinal, Histiocytic Sarcoma     |                                                                          |          1 |
      Mediastinal, Leukemia Mononuclear    |                                                                          |          2 |
      Pancreatic, Histiocytic Sarcoma      |                                                                          |          1 |
      Pancreatic, Leukemia Mononuclear     |    X  X                                                                  |          4 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |       X                                X                                 |         15 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  69        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  75                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 4| 5| 2| 7| 2| 7| 7| 2| 6| 7| 7| 2| 7| 2| 7| 7|              |            |
                             DAY ON TEST   | 2| 2| 2| 2| 6| 9| 7| 2| 7| 2| 3| 7| 3| 3| 3| 7| 2| 7| 2| 2|              |            |
                                           | 9| 9| 9| 9| 2| 0| 5| 9| 5| 9| 0| 6| 9| 0| 0| 5| 9| 6| 9| 9|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    1000 PPM                               | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Leukemia Mononuclear                 |    X           X                                                         |         17 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X                       X                                 |         23 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  68        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |                                        X                                 |          4 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +               |  61        |
      Fibroadenoma                         |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Fibroma                              |                                     X                                    |          3 |
      Keratoacanthoma                      |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X                       X                                 |         15 |
      Mesothelioma Malignant, Metastatic,  |                                                                          |            |
           Heart                           |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Polyp                                |                               X                                          |          1 |
      Squamous Cell Carcinoma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  67        |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  76                                                               
NTP Experiment-Test: 05150-01                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                   METHYLPHENIDATE HYDROCHLORIDE                               Date: 04/01/97  
Route: DOSED FEED                                                                                                 Time: 15:19:40  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 4| 5| 2| 7| 2| 7| 7| 2| 6| 7| 7| 2| 7| 2| 7| 7|              |            |
                             DAY ON TEST   | 2| 2| 2| 2| 6| 9| 7| 2| 7| 2| 3| 7| 3| 3| 3| 7| 2| 7| 2| 2|              |            |
                                           | 9| 9| 9| 9| 2| 0| 5| 9| 5| 9| 0| 6| 9| 0| 0| 5| 9| 6| 9| 9|              |            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     O      |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|              |     T      |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|              |     A      |
    1000 PPM                               | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|              |     L      |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|              |            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Lipoma                               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  64        |
      Papilloma                            |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +               |  70        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Leukemia Mononuclear                 |    X  X        X                       X                                 |         23 |
      Mesothelioma Malignant               |                                                                          |          2 |
 __________________________________________________________________________________________________________________________________ 
                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  
                                                             Page  77                                                               
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