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TDMS Study 88070-03 Pathology Tables

NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  115-11-0007

       Lock Date:  10/05/95

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































                                                              Page   1

NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 5| 7| 6| 6| 7| 4| 4| 4| 7| 7| 5| 5| 5| 7| 7| 7| 7| 4| 7| 4| 7|             
                             DAY ON TEST   | 3| 3| 3| 2| 7| 1| 6| 4| 3| 8| 9| 4| 3| 3| 8| 5| 2| 3| 0| 3| 3| 2| 3| 8| 3|             
                                           | 3| 3| 3| 0| 3| 4| 3| 2| 3| 8| 6| 0| 3| 4| 1| 2| 9| 4| 5| 4| 4| 1| 4| 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   | 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|             
    CONTROL                                | 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                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |          X                 X                                             |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |    X                             X     X  X              X               |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                 4                        |             
      Parasite Metazoan                    | X           X              X                                X            |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                   2      |             
      Basophilic Focus                     | X     X  X     X     X  X        X  X  X  X  X     X  X  X  X  X  X     X|             
      Clear Cell Focus                     |                                                    X              X      |             
      Degeneration, Fatty                  |          3  2  3  2           1                 3     2                  |             
      Eosinophilic Focus                   |                         X  X                                             |             
      Hepatodiaphragmatic Nodule           |             X                                                            |             
      Inflammation, Granulomatous          |                                                                          |             
      Mixed Cell Focus                     | X  X                                                  X     X            |             
      Necrosis                             |                                              2     2                     |             
      Regeneration                         |                                                                          |             
      Thrombosis                           |          2                                                               |             
      Bile Duct, Hyperplasia               |          2  2  2                                         2               |             
      Centrilobular, Necrosis              |                2  1  1                                                   |             
                                            __________________________________________________________________________|             
   Mesentery                               |    +        +                 +                 +           +            |             
      Fat, Hemorrhage                      |                                                             1            |             
      Fat, Necrosis                        |    2        2                 2                 2           2            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              | 2                    2     2     2        1                          1   |             
      Basophilic Focus                     |                            X                                             |             
      Metaplasia, Hepatocyte               |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                       2                  |             
      Mineralization                       |                                                                          |             
      Necrosis                             |          4     3  3                             3                        |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |          1        1                                                      |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1  2  1     2  1        1     1  1  1  2  1        2  2     2     1     2|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 5| 7| 6| 6| 7| 4| 4| 4| 7| 7| 5| 5| 5| 7| 7| 7| 7| 4| 7| 4| 7|             
                             DAY ON TEST   | 3| 3| 3| 2| 7| 1| 6| 4| 3| 8| 9| 4| 3| 3| 8| 5| 2| 3| 0| 3| 3| 2| 3| 8| 3|             
                                           | 3| 3| 3| 0| 3| 4| 3| 2| 3| 8| 6| 0| 3| 4| 1| 2| 9| 4| 5| 4| 4| 1| 4| 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   | 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|             
    CONTROL                                | 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                   |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Cystic                 |                                                                          |             
      Hyperplasia                          | 2                       2        2           2              1            |             
      Hypertrophy                          |          2           2  1           1  2              3                  |             
      Necrosis                             |          2                                      1                        |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    1  1        3     1                             2     2               |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |                            2     2           3                           |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  | 1     1  1  2  1  1  2  1  1     2  3  2  2  1  1  1  2  3        2  1  2|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                     2                                    |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 2           3  2  2  3                       3                           |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Vagina                                  |          +                                                               |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |          4                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node                              |          +  +     +              +                                       |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  +  +  +  +  M  +  M  +  +  +  M  M  +  +  M  +  M  +  M  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | M  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                            3                 3                       4   |             
      Hemorrhage                           |          2                                                               |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                               3                                          |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 5| 7| 6| 6| 7| 4| 4| 4| 7| 7| 5| 5| 5| 7| 7| 7| 7| 4| 7| 4| 7|             
                             DAY ON TEST   | 3| 3| 3| 2| 7| 1| 6| 4| 3| 8| 9| 4| 3| 3| 8| 5| 2| 3| 0| 3| 3| 2| 3| 8| 3|             
                                           | 3| 3| 3| 0| 3| 4| 3| 2| 3| 8| 6| 0| 3| 4| 1| 2| 9| 4| 5| 4| 4| 1| 4| 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   | 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|             
    CONTROL                                | 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                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Inflammation, Chronic Active         |                                        2                                 |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperostosis                         |                1        2           2  2           1                     |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          |                            1              2                              |             
      Alveolar Epithelium, Hyperplasia     |                   1     1                    1           1               |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |       1     1                                   1           1  2         |             
      Thrombosis                           |                3  2                                                      |             
      Olfactory Epithelium, Degeneration,  |                                                                          |             
           Hyaline                         | 1     1  2  1  1  2  2  1  1  1  2     2  2     1  2  2  1  1     1  1  1|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                    +           +                           |             
      Cataract                             |             2                    3           3                           |             
      Retina, Atrophy                      |                                  3           3                           |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infarct                              |    2                                                                     |             
      Nephropathy                          | 3  2  2  1     1  2  1  1     3  1  2  1  2  1  2  3  2     2  1  3     2|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 3| 7| 5| 7| 6| 7| 7| 6|            |
                             DAY ON TEST   | 9| 3| 4| 1| 3| 2| 2| 3| 3| 3| 3| 6| 7| 3| 3| 3| 2| 9| 3| 5| 0| 0| 3| 3| 4|            |
                                           | 1| 4| 2| 5| 4| 2| 6| 4| 4| 4| 4| 4| 8| 5| 5| 5| 0| 0| 5| 2| 5| 8| 5| 5| 8|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 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|      L     |
                                           | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    | X        X                                      X                        |      5     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +|  47        |
      Parasite Metazoan                    |                            X  X                                   X      |      8     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Inflammation, Acute                  |                                                                          |      1  4.0|
      Parasite Metazoan                    |                                     X                                    |      5     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Basophilic Focus                     | X  X  X     X  X  X  X  X  X  X  X     X  X  X  X     X           X  X   |     36     |
      Clear Cell Focus                     |             X              X     X                                X      |      6     |
      Degeneration, Fatty                  |                3  2                 2                          2        2|     12  2.3|
      Eosinophilic Focus                   |    X                                                  X        X     X   |      6     |
      Hepatodiaphragmatic Nodule           |             X           X                                            X   |      4     |
      Inflammation, Granulomatous          |                                  1                                       |      1  1.0|
      Mixed Cell Focus                     |       X                                   X     X                        |      7     |
      Necrosis                             |                                                                          |      2  2.0|
      Regeneration                         |                                                                4         |      1  4.0|
      Thrombosis                           |                                                                          |      1  2.0|
      Bile Duct, Hyperplasia               |    2              2                                      2     2        1|      9  1.9|
      Centrilobular, Necrosis              |                                                                2         |      4  1.5|
                                            __________________________________________________________________________|____________|
   Mesentery                               |          +                       +              +                        |   8        |
      Fat, Hemorrhage                      |                                                                          |      1  1.0|
      Fat, Necrosis                        |          2                       2              2                        |      8  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                         1                                2     2         |      9  1.7|
      Basophilic Focus                     |                                                                          |      1     |
      Metaplasia, Hepatocyte               | 2                                                                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                                                          |      1  2.0|
      Mineralization                       |                               1                                          |      1  1.0|
      Necrosis                             |                2                                   1                    3|      7  2.7|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Necrosis                             |                                                 2                        |      3  1.3|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   5                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 3| 7| 5| 7| 6| 7| 7| 6|            |
                             DAY ON TEST   | 9| 3| 4| 1| 3| 2| 2| 3| 3| 3| 3| 6| 7| 3| 3| 3| 2| 9| 3| 5| 0| 0| 3| 3| 4|            |
                                           | 1| 4| 2| 5| 4| 2| 6| 4| 4| 4| 4| 4| 8| 5| 5| 5| 0| 0| 5| 2| 5| 8| 5| 5| 8|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 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|      L     |
                                           | 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 - cont                  |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 2     1     2     1  1  2  2  2              1  2     2     2     2  1   |     30  1.5|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration, Cystic                 |          2              2                                                |      2  2.0|
      Hyperplasia                          |             2        2     1  2        2  2  2              2  2  2      |     15  1.9|
      Hypertrophy                          |                   1     2                       1  2           2         |     11  1.7|
      Necrosis                             |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                     2                    3     2     2   |     10  1.9|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pars Distalis, Hyperplasia           |    1                                         3           2              3|      7  2.3|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  | 1  2        1     2  3     1  1  1  2  2     1     1     2     2  1     2|     37  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |    2                                      2              2               |      9  2.3|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                          +     +         |   6        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  M  +  M  +  M  +  +  +  +  +  +  M  +  M  +  +  +  +  +|  36        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  M  +  +  +  +  +  M  +  +|  42        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   6                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 3| 7| 5| 7| 6| 7| 7| 6|            |
                             DAY ON TEST   | 9| 3| 4| 1| 3| 2| 2| 3| 3| 3| 3| 6| 7| 3| 3| 3| 2| 9| 3| 5| 0| 0| 3| 3| 4|            |
                                           | 1| 4| 2| 5| 4| 2| 6| 4| 4| 4| 4| 4| 8| 5| 5| 5| 0| 0| 5| 2| 5| 8| 5| 5| 8|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 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|      L     |
                                           | 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     | 3                                3                                       |      5  3.2|
      Hemorrhage                           |                                                                          |      1  2.0|
      Necrosis                             |                                                                         2|      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  48        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |       2                                                                  |      2  2.5|
      Inflammation, Chronic                |                                                                   2      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                   3                                                      |      1  3.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperostosis                         |       1                                      2        3        3         |      9  1.9|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                      3                                                   |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Granulomatous          | 1                    2        1  1                                   1   |      7  1.3|
      Alveolar Epithelium, Hyperplasia     |                2  1     2                    1        1                  |      9  1.2|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                      2           1                                       |      7  1.3|
      Thrombosis                           |                                                                          |      2  2.5|
      Olfactory Epithelium, Degeneration,  |                                                                          |            |
           Hyaline                         | 2  2  1     1  2  1  2  2  2  2  1  2  1  2  2  1  1  2  1     1  1  1  2|     44  1.5|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                         +|   4        |
      Cataract                             |                                                                         4|      4  3.0|
      Retina, Atrophy                      |                                                                         4|      3  3.3|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   7                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7| 3| 7| 5| 7| 6| 7| 7| 6|            |
                             DAY ON TEST   | 9| 3| 4| 1| 3| 2| 2| 3| 3| 3| 3| 6| 7| 3| 3| 3| 2| 9| 3| 5| 0| 0| 3| 3| 4|            |
                                           | 1| 4| 2| 5| 4| 2| 6| 4| 4| 4| 4| 4| 8| 5| 5| 5| 0| 0| 5| 2| 5| 8| 5| 5| 8|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 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|      L     |
                                           | 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|            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infarct                              |                                                                          |      1  2.0|
      Nephropathy                          | 1  1  2  2  3  3  2  3  2  2  2  1  1  3  2  1  2  1  2  2  2  2  2  2  2|     46  1.9|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   8                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 5| 7| 7| 0| 7| 7| 7| 6| 7| 4| 7| 6| 7| 7| 5| 6| 4| 6| 7| 6| 6| 6| 7| 7|             
                             DAY ON TEST   | 9| 4| 2| 0| 1| 3| 3| 1| 6| 3| 4| 3| 0| 3| 3| 6| 0| 9| 8| 3| 9| 8| 6| 3| 3|             
                                           | 6| 8| 2| 8| 3| 3| 3| 9| 2| 3| 0| 3| 8| 4| 4| 5| 3| 4| 8| 4| 2| 8| 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|             
    500 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                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  I  I  +  +  I  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Basophilic Focus                     | X  X  X  X     X  X     X     X  X  X  X  X     X        X     X     X  X|             
      Clear Cell Focus                     |                X  X           X  X     X                             X   |             
      Degeneration, Fatty                  |                         2                    2  1  3  2        2         |             
      Eosinophilic Focus                   |                                  X                             X     X   |             
      Hepatodiaphragmatic Nodule           |                X              X           X  X                 X        X|             
      Mitotic Alteration                   |                                                                          |             
      Mixed Cell Focus                     |       X                                         X           X     X      |             
      Regeneration                         |       3                                                                  |             
      Bile Duct, Hyperplasia               |       1                                   3                    2         |             
      Centrilobular, Necrosis              |    3                    2           2     2                              |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +           +  +  +     +        +                       +         |             
      Fat, Necrosis                        |       2           3  3  3     2        2                       2         |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |       2                 2  2                                   1         |             
      Basophilic Focus                     |                X                                      X                  |             
      Hyperplasia                          |                      2                                                   |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                   2                                                      |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Basal Cell              |                                                                         2|             
      Necrosis                             |                                              2     4  2     3            |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |                                                    2                     |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                      +   |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 2     2  1        2  2           1     1        1           1     1  2  2|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   9                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 5| 7| 7| 0| 7| 7| 7| 6| 7| 4| 7| 6| 7| 7| 5| 6| 4| 6| 7| 6| 6| 6| 7| 7|             
                             DAY ON TEST   | 9| 4| 2| 0| 1| 3| 3| 1| 6| 3| 4| 3| 0| 3| 3| 6| 0| 9| 8| 3| 9| 8| 6| 3| 3|             
                                           | 6| 8| 2| 8| 3| 3| 3| 9| 2| 3| 0| 3| 8| 4| 4| 5| 3| 4| 8| 4| 2| 8| 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|             
    500 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                   |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Degeneration, Cystic                 |                                  2                                       |             
      Hyperplasia                          |                   3     2        1                          2     2  1   |             
      Hypertrophy                          |                   1  2                       1                           |             
      Thrombosis                           |    2                                                                     |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |          3           1  2  2                                             |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                   2                                                      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |                                                                          |             
      Pars Distalis, Hyperplasia           |          3                          4                    3              2|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  | 1  1  1  3              2  2  2  2  3     2  2     2  2        1  2  2  1|             
      Follicular Cell, Hyperplasia         |                                                          1               |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |       4                    4                                   1         |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cervix, Hypertrophy                  |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                         1|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                           +  +                           |             
      Pancreatic, Ectasia                  |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  +  +  M  +  +  +  +  +  M  M  M  M  +  +  M  +  +  M  M  M  M  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Infiltration Cellular, Plasma Cell   |          2                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                                                          X               |             
      Fibrosis                             |                   1                       2                              |             
      Hematopoietic Cell Proliferation     |    2                                                                     |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  10                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 5| 7| 7| 0| 7| 7| 7| 6| 7| 4| 7| 6| 7| 7| 5| 6| 4| 6| 7| 6| 6| 6| 7| 7|             
                             DAY ON TEST   | 9| 4| 2| 0| 1| 3| 3| 1| 6| 3| 4| 3| 0| 3| 3| 6| 0| 9| 8| 3| 9| 8| 6| 3| 3|             
                                           | 6| 8| 2| 8| 3| 3| 3| 9| 2| 3| 0| 3| 8| 4| 4| 5| 3| 4| 8| 4| 2| 8| 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|             
    500 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst Epithelial Inclusion            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperostosis                         |                      1                 3  1                    1         |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          |                                                 1                        |             
      Inflammation, Suppurative            |                                                             3            |             
      Alveolar Epithelium, Hyperplasia     |                      1     1           2                       1         |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |             2                                                            |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                              1                           |             
      Thrombosis                           |    3                    1           4                                    |             
      Olfactory Epithelium, Degeneration,  |                                                                          |             
           Hyaline                         | 2  3  3  3     2  3  3  3  2  2  3  3  3  3  2  2  2  3  3  2  3  2  2  2|             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                              1                           |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                         +                                                |             
                                            __________________________________________________________________________|             
   Eye                                     |                +              +                 +                        |             
      Cataract                             |                3              3                                          |             
      Retina, Atrophy                      |                3              3                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy                          | 1     2  1     2  1  2  1  2     2  1  3  2  1  2  2  2  1  1  2  3  2  2|             
      Renal Tubule, Hyperplasia            |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  11                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 5| 7| 7| 7| 5| 7| 6| 5| 7| 7| 7| 6| 6| 2| 7| 7| 4| 4| 7| 4| 7| 7|            |
                             DAY ON TEST   | 3| 1| 3| 8| 3| 3| 1| 7| 3| 3| 3| 0| 1| 3| 2| 3| 1| 3| 3| 2| 7| 3| 5| 3| 3|            |
                                           | 4| 6| 4| 0| 4| 4| 8| 3| 4| 0| 4| 1| 4| 4| 1| 5| 6| 4| 5| 0| 9| 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| 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| 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| 3| 3| 3| 3| 3|      A     |
    500 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|      L     |
                                           | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                              3                           |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    | X                 X     X                                               X|      5     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Acute                  |                                              4                           |      1  4.0|
      Parasite Metazoan                    |                                                       X              X   |      2     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Inflammation, Acute                  |                                              3                           |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Inflammation, Acute                  |                                              2                           |      1  2.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                1     2                       1                           |      3  1.3|
      Basophilic Focus                     | X  X  X     X  X  X  X  X  X  X  X  X  X           X  X     X  X     X  X|     36     |
      Clear Cell Focus                     |    X                                                                 X  X|      9     |
      Degeneration, Fatty                  |          3           1                             2     3               |     10  2.1|
      Eosinophilic Focus                   |    X                    X                                               X|      6     |
      Hepatodiaphragmatic Nodule           |       X                                                                  |      7     |
      Mitotic Alteration                   |                                                 4                        |      1  4.0|
      Mixed Cell Focus                     |             X  X                 X  X     X                       X     X|     11     |
      Regeneration                         |                                                                          |      1  3.0|
      Bile Duct, Hyperplasia               |                2                             1                           |      5  1.8|
      Centrilobular, Necrosis              |                                                                          |      4  2.3|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                   +     +           +                                    |  10        |
      Fat, Necrosis                        |                   2     2           2                                    |     10  2.3|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |    1           2           2  2        2           2                    1|     11  1.7|
      Basophilic Focus                     |                X              X                                          |      4     |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Basal Cell              |                                                                          |      1  2.0|
      Necrosis                             |          2                                1        4                     |      7  2.6|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Necrosis                             |                                                    3                     |      2  2.5|
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  12                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 5| 7| 7| 7| 5| 7| 6| 5| 7| 7| 7| 6| 6| 2| 7| 7| 4| 4| 7| 4| 7| 7|            |
                             DAY ON TEST   | 3| 1| 3| 8| 3| 3| 1| 7| 3| 3| 3| 0| 1| 3| 2| 3| 1| 3| 3| 2| 7| 3| 5| 3| 3|            |
                                           | 4| 6| 4| 0| 4| 4| 8| 3| 4| 0| 4| 1| 4| 4| 1| 5| 6| 4| 5| 0| 9| 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| 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| 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| 3| 3| 3| 3| 3|      A     |
    500 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|      L     |
                                           | 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 - cont                  |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1  2  2     1  1  1     1  2     1  1  2  1        1  2     1  2  1      |     29  1.4|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                              4                           |      1  4.0|
      Degeneration, Cystic                 |                                                       2                  |      2  2.0|
      Hyperplasia                          | 2     2        2  2                 2  2           2  2           2     2|     17  1.9|
      Hypertrophy                          |       2                          2     2                       2        2|      8  1.8|
      Thrombosis                           |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                        3                                 |      5  2.2|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  49        |
      Pars Distalis, Angiectasis           |                                                    3                     |      1  3.0|
      Pars Distalis, Hyperplasia           |                      3                                   2     2         |      7  2.7|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  | 1  2     2  1           2     1  2  3     1  1     1  1  1     1  1  2  1|     34  1.6|
      Follicular Cell, Hyperplasia         |                   1                                                      |      2  1.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                      2   |      4  2.8|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cervix, Hypertrophy                  |                                                       2                  |      1  2.0|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                          +               |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                       +                  |   3        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  13                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 5| 7| 7| 7| 5| 7| 6| 5| 7| 7| 7| 6| 6| 2| 7| 7| 4| 4| 7| 4| 7| 7|            |
                             DAY ON TEST   | 3| 1| 3| 8| 3| 3| 1| 7| 3| 3| 3| 0| 1| 3| 2| 3| 1| 3| 3| 2| 7| 3| 5| 3| 3|            |
                                           | 4| 6| 4| 0| 4| 4| 8| 3| 4| 0| 4| 1| 4| 4| 1| 5| 6| 4| 5| 0| 9| 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| 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| 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| 3| 3| 3| 3| 3|      A     |
    500 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|      L     |
                                           | 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Pancreatic, Ectasia                  |                                                       2                  |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  M  +  M  +  M  M  M  +  +  M  +  +  M  +  +|  31        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  46        |
      Infiltration Cellular, Plasma Cell   |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accessory Spleen                     |                                                                          |      1     |
      Fibrosis                             |                                                                2         |      3  1.7|
      Hematopoietic Cell Proliferation     |                                                 4                        |      2  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +|  47        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |       3                                            2                     |      2  2.5|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst Epithelial Inclusion            |                                        X                                 |      1     |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperostosis                         |       3  3              2                                                |      7  2.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Granulomatous          |    1        1           1                                               1|      5  1.0|
      Inflammation, Suppurative            |                                                                          |      1  3.0|
      Alveolar Epithelium, Hyperplasia     |                2           3              1           1                 1|      9  1.4|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                     2                                    |      2  1.5|
      Thrombosis                           |                                                                          |      3  2.7|
      Olfactory Epithelium, Degeneration,  |                                                                          |            |
           Hyaline                         | 2  2  2  2  2  2  2  1  2  2  3  3  3  2  2  2     3  2     2  3  2  3  3|     47  2.4|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  14                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 5| 7| 7| 7| 5| 7| 6| 5| 7| 7| 7| 6| 6| 2| 7| 7| 4| 4| 7| 4| 7| 7|            |
                             DAY ON TEST   | 3| 1| 3| 8| 3| 3| 1| 7| 3| 3| 3| 0| 1| 3| 2| 3| 1| 3| 3| 2| 7| 3| 5| 3| 3|            |
                                           | 4| 6| 4| 0| 4| 4| 8| 3| 4| 0| 4| 1| 4| 4| 1| 5| 6| 4| 5| 0| 9| 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| 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| 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| 3| 3| 3| 3| 3|      A     |
    500 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|      L     |
                                           | 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                 |                                                                          |            |
                                           |                                                                          |            |
           Squamous                        |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Eye                                     |                      +                                                   |   4        |
      Cataract                             |                      4                                                   |      3  3.3|
      Retina, Atrophy                      |                      4                                                   |      3  3.3|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy                          | 1  2  2  2  3  2  2  1  2  2  1  2  2  2  2  1     1  2  1  2  2  1  2  2|     46  1.7|
      Renal Tubule, Hyperplasia            |             3                                                            |      1  3.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  15                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7|             
                             DAY ON TEST   | 3| 0| 2| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 2| 0| 3|             
                                           | 3| 1| 2| 3| 3| 3| 6| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 7| 5| 0| 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 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|             
    2000 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  I  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                      X  X|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  A  +|             
      Parasite Metazoan                    |                      X                 X                                 |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  A  +|             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  A  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |    1              2              2              1                        |             
      Basophilic Focus                     | X  X  X  X  X  X  X  X  X  X  X  X  X  X  X  X  X  X  X  X     X     X  X|             
      Clear Cell Focus                     |                X           X                 X        X                  |             
      Degeneration, Cystic                 |                                                                          |             
      Degeneration, Fatty                  |    2  3                                                  3  3     1      |             
      Eosinophilic Focus                   |                            X              X                              |             
      Hematopoietic Cell Proliferation     |                                                 1                        |             
      Hepatodiaphragmatic Nodule           |                                                                X  X      |             
      Mixed Cell Focus                     |             X              3                                   X        X|             
      Necrosis                             |                                  2                                       |             
      Regeneration                         | 2                                         3                              |             
      Bile Duct, Hyperplasia               |                                                 1        2  2            |             
      Centrilobular, Necrosis              |                                                 1        1  1            |             
                                            __________________________________________________________________________|             
   Mesentery                               | +  +  +                                +                 +  +  +  +      |             
      Thrombosis                           |                                                                          |             
      Fat, Necrosis                        | 2  2  2                                2                 2  2  2  2      |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Atrophy                              | 2                 1     2  1  1  1  2        1     1  1                  |             
      Basophilic Focus                     |                   X                                                      |             
      Hyperplasia                          |                            3                                             |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |    1  3           2                                                      |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |          1                                                               |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Necrosis                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  16                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7|             
                             DAY ON TEST   | 3| 0| 2| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 2| 0| 3|             
                                           | 3| 1| 2| 3| 3| 3| 6| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 7| 5| 0| 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 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|             
    2000 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|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Cardiomyopathy                       |    2        2  1  1  1  2  2  2  2  2  1  2  2  2  2  2  1     2  1     2|             
      Atrium, Thrombosis                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Degeneration, Cystic                 |                                     2              2           3         |             
      Hyperplasia                          | 2     2           2        2  2  2  2  2  2              2        1      |             
      Hypertrophy                          |                         1  2                 2        2     3  2         |             
      Necrosis                             |                   3                                                      |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Hyperplasia                          |                                                 2  1     2              2|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Pars Distalis, Hyperplasia           | 1                    2                          2     1     2           3|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      C-Cell, Hyperplasia                  | 1     1     2  3  2  1  1     2  1     2  1     2  3  1  2              3|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Hyperplasia                          |                                                 2                        |             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |       2  2                                            3  3               |             
      Inflammation, Granulomatous          |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Hyperplasia, Reticulum Cell          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                          +               |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Infiltration Cellular, Plasma Cell   |                                                 4                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  M  M  +  +  +  +  M  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Fibrosis                             |                                           2              2  2            |             
      Hematopoietic Cell Proliferation     |                   2                             4                       4|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  17                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6| 7| 7|             
                             DAY ON TEST   | 3| 0| 2| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 2| 0| 3|             
                                           | 3| 1| 2| 3| 3| 3| 6| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5| 7| 5| 0| 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 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|             
    2000 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  M  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  M|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                                                          |             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
      Inflammation, Chronic Active         |                                                       2                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperostosis                         |                      2  2  2  2                                      2   |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          |                1        1  1  1                 1                        |             
      Alveolar Epithelium, Hyperplasia     | 1                    2  1              1                                 |             
      Bronchiole, Hyperplasia              |                      2                                                   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                         1           2                 1        1  1      |             
      Thrombosis                           |                                                             2            |             
      Olfactory Epithelium, Degeneration,  |                                                                          |             
           Hyaline                         |    3  3  3  3  4  2  3  2  3  3  3  3  3  3  2  3  3  2  2  3  2  3     3|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                      +                    +           +                 +|             
      Cataract                             |                      3                    4           3                 4|             
      Retina, Atrophy                      |                      4                    4           4                 3|             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
      Nephropathy                          | 2  2  2  2  2  2  2  2  2  2  2  2  3  2  2  2  1  2  3  2     2  2     2|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  18                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 3| 6| 7| 7| 7| 6| 5| 7| 7| 6| 5| 7| 7| 5|            |
                             DAY ON TEST   | 2| 3| 3| 3| 3| 3| 3| 3| 3| 8| 8| 9| 4| 3| 3| 3| 8| 6| 2| 3| 5| 5| 3| 3| 3|            |
                                           | 6| 5| 5| 5| 5| 5| 5| 5| 5| 4| 0| 9| 4| 5| 5| 5| 6| 0| 0| 5| 1| 2| 5| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 5| 5| 5| 5| 5|      A     |
    2000 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|      L     |
                                           | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                             4            |      1  4.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |                         X                                                |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                   X  X  X                                                |      5     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Parasite Metazoan                    |                         X                                            X   |      4     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Necrosis                             |                                                             4            |      1  4.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      4  1.5|
      Basophilic Focus                     |    X  X  X  X  X  X  X  X  X  X     X  X  X  X  X  X  X  X        X  X   |     43     |
      Clear Cell Focus                     |          X  X  X     X  X              X  X  X                           |     12     |
      Degeneration, Cystic                 |                               4              2                           |      2  3.0|
      Degeneration, Fatty                  | 3                             1     2                 2     3  2        2|     12  2.3|
      Eosinophilic Focus                   |       X     X                                                           X|      5     |
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|
      Hepatodiaphragmatic Nodule           |          X                    X                 X                        |      5     |
      Mixed Cell Focus                     |                   X  X  X        X     X                                 |      9  3.0|
      Necrosis                             |                                                 1                        |      2  1.5|
      Regeneration                         |                                                                          |      2  2.5|
      Bile Duct, Hyperplasia               | 2  1                                                        2           2|      7  1.7|
      Centrilobular, Necrosis              | 1                                                     1                  |      5  1.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                            +           +           +        +            |  12        |
      Thrombosis                           |                                                             3            |      1  3.0|
      Fat, Necrosis                        |                            2           2           2        3            |     12  2.1|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              | 1     4  2  1  2                                      2                 3|     17  1.6|
      Basophilic Focus                     |    X              X                                                      |      3     |
      Hyperplasia                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Necrosis                             | 3                             1  2                                       |      6  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                                                                          |      1  1.0|
      Necrosis                             | 3                                                                        |      1  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  19                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 3| 6| 7| 7| 7| 6| 5| 7| 7| 6| 5| 7| 7| 5|            |
                             DAY ON TEST   | 2| 3| 3| 3| 3| 3| 3| 3| 3| 8| 8| 9| 4| 3| 3| 3| 8| 6| 2| 3| 5| 5| 3| 3| 3|            |
                                           | 6| 5| 5| 5| 5| 5| 5| 5| 5| 4| 0| 9| 4| 5| 5| 5| 6| 0| 0| 5| 1| 2| 5| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 5| 5| 5| 5| 5|      A     |
    2000 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|      L     |
                                           | 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 - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                             +            |   1        |
      Necrosis                             |                                                             4            |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cardiomyopathy                       | 2     1  2  2  2  1  2  3     1     2  2  1  2        2  2        2  2   |     37  1.8|
      Atrium, Thrombosis                   | 3                                                                        |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Degeneration, Cystic                 |                         2                                                |      4  2.3|
      Hyperplasia                          | 3     2  2     2  2     2  2  2  2     2     2        1              2   |     24  2.0|
      Hypertrophy                          |                2        1                                   2            |      9  1.9|
      Necrosis                             |                                                 3              2         |      3  2.7|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          | 2                                                                    2   |      6  1.8|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                2         |      1  2.0|
      Pars Distalis, Hyperplasia           |          3  4                 2        4              2                  |     11  2.4|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Hyperplasia                  | 2  1  2     2  2  1  1  1  2  1  1  2  1  1  2  1  3  2  1  1     1  1   |     38  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +|  47        |
      Hyperplasia                          |       3  3                          3                                3   |      5  2.8|
      Inflammation, Chronic Active         |                                                                      3   |      1  3.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      4  2.5|
      Inflammation, Granulomatous          |    1                                                                     |      1  1.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fibrosis                             |                                                             4            |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  20                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 3| 6| 7| 7| 7| 6| 5| 7| 7| 6| 5| 7| 7| 5|            |
                             DAY ON TEST   | 2| 3| 3| 3| 3| 3| 3| 3| 3| 8| 8| 9| 4| 3| 3| 3| 8| 6| 2| 3| 5| 5| 3| 3| 3|            |
                                           | 6| 5| 5| 5| 5| 5| 5| 5| 5| 4| 0| 9| 4| 5| 5| 5| 6| 0| 0| 5| 1| 2| 5| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 5| 5| 5| 5| 5|      A     |
    2000 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|      L     |
                                           | 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|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia, Reticulum Cell          |                               2                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +                                                                       +|   3        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  M  +  M  M  M  M  +  +  +  +  M  +  +  M  M  +  +  M  +  +  +  +|  36        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Plasma Cell   |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  M  +  +  +  +  +  M  +  M  M  +  +  +  +  +  +  +  +  +  M  +  +  +|  39        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Fibrosis                             |                                           2     1        2               |      6  1.8|
      Hematopoietic Cell Proliferation     |                                                                          |      3  3.3|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  45        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                  2                                       |      1  2.0|
      Inflammation, Acute                  |                                                 4                        |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                              2                           |      1  2.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperostosis                         |                                           2     3              2  3  3  3|     11  2.4|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Granulomatous          |             1        1                                            1     1|      9  1.0|
      Alveolar Epithelium, Hyperplasia     |                3                       1                             1   |      7  1.4|
      Bronchiole, Hyperplasia              |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |          1                                   2  3                        |      8  1.5|
      Thrombosis                           | 4                                                                        |      2  3.0|
      Olfactory Epithelium, Degeneration,  |                                                                          |            |
           Hyaline                         | 2  2  3  3  3  3  2  3  3  2  2  2  3  3  3  3  3  3  2  3  3  3  3  3  4|     48  2.8|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  21                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 3| 6| 7| 7| 7| 6| 5| 7| 7| 6| 5| 7| 7| 5|            |
                             DAY ON TEST   | 2| 3| 3| 3| 3| 3| 3| 3| 3| 8| 8| 9| 4| 3| 3| 3| 8| 6| 2| 3| 5| 5| 3| 3| 3|            |
                                           | 6| 5| 5| 5| 5| 5| 5| 5| 5| 4| 0| 9| 4| 5| 5| 5| 6| 0| 0| 5| 1| 2| 5| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 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|      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| 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| 5| 5| 5| 5| 5|      A     |
    2000 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|      L     |
                                           | 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                 |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                         +     +                                          |   6        |
      Cataract                             |                         3     3                                          |      6  3.3|
      Retina, Atrophy                      |                         3     4                                          |      6  3.7|
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                               +                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Nephropathy                          | 2  2  2  1  2  2  2  2  2  3  2  2  2  2  2  2  2        1  1  2  2  3  2|     46  2.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  22                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 7| 6| 7| 7| 5| 7| 6| 5| 7| 6| 6| 7| 7| 7| 7| 5| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 6| 0| 5| 3| 2| 3| 2| 9| 3| 6| 4| 3| 3| 7| 3| 3| 3| 3| 0| 3| 3| 0| 6| 0| 8|             
                                           | 4| 6| 0| 3| 8| 3| 9| 7| 3| 3| 7| 3| 0| 4| 4| 4| 4| 4| 0| 4| 4| 2| 8| 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| 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   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    8000 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                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                         X                                                |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |          X                                                  X            |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |    X              X                                                  X   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  A  +|             
      Parasite Metazoan                    |                                              X                           |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                      3                                                   |             
      Basophilic Focus                     | X  X  X  X        X  X  X  X     X     X  X  X  X  X     X  X  X  X      |             
      Clear Cell Focus                     |          X     X                             X  X                        |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Fatty                  |       2     3              3  3     1                                   1|             
      Eosinophilic Focus                   |    X     X                       X        X     X        X        X      |             
      Hepatodiaphragmatic Nodule           |                   X                                                  X   |             
      Mixed Cell Focus                     | X     X        X     X                    X                              |             
      Regeneration                         |    4                                3                                    |             
      Bile Duct, Hyperplasia               |    2                                3  1                       1         |             
      Centrilobular, Necrosis              |                               1     2                             4  2   |             
                                            __________________________________________________________________________|             
   Mesentery                               | +                                   +                          +         |             
      Artery, Inflammation, Chronic Active |                                                                3         |             
      Fat, Necrosis                        | 2                                   2                          2         |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |             +                                                            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |    2  2  1           1                       1        1                  |             
      Basophilic Focus                     |                X                                   X                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              | 2                                                                        |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |       3     2              2  3                       2                  |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |                                     2                                    |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Hyperplasia, Squamous                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1        2     1     1  2     1  1  1     2     1  1     2  1  1  1     1|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  23                                                               
NTP Experiment-Test: 88070-03                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                             ISOBUTENE                                         Date: 06/11/97  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 10:56:43  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 6| 7| 6| 7| 7| 5| 7| 6| 5| 7| 6| 6| 7| 7| 7| 7| 5| 7| 7| 7| 6| 4| 5|             
                             DAY ON TEST   | 6| 0| 5| 3| 2| 3| 2| 9| 3| 6| 4| 3| 3| 7| 3| 3| 3| 3| 0| 3| 3| 0| 6| 0| 8|             
                                           | 4| 6| 0| 3| 8| 3| 9| 7| 3| 3| 7| 3| 0| 4| 4| 4| 4| 4| 0| 4| 4| 2| 8| 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| 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   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    8000 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                        2                                 |             
      Degeneration, Cystic                 |                                                                          |             
      Hyperplasia                          |             2           3  2  2  2        2  2     1  3  2     1         |             
      Hypertrophy                          |          2                                2     2                 2      |             
      Necrosis                             |                                                                          |             
      Vacuolization Cytoplasmic            |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                            2        3                                   2|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |             4                                                            |             
      Pars Distalis, Cyst                  |                                                                         4|             
      Pars Distalis, Hyperplasia           |             2                                      2                    3|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  | 1  1  2     2  1        1        1  2        1  1  1     1  1  2  1     1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                      2   |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Necrosis                             |                                                                         4|             
                                            __________________________________________________________________________|             
   Vagina                                  |                            +                                             |             
      Inflammation, Suppurative            |                            3                                             |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                           2                              |             
      Hyperplasia, Histiocytic             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |