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TDMS Study 60968-02 Pathology Tables

NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  0078-84-2

       Lock Date:  05/12/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































                                                              Page   1

NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 6| 6| 7| 7| 6| 7| 7| 0| 7| 0| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 0| 9| 3| 4| 2| 4| 3| 3| 9| 3| 2| 7| 3| 6| 3| 3| 3| 8| 3|             
                                           | 6| 6| 1| 6| 6| 6| 1| 6| 5| 6| 3| 6| 5| 7| 1| 7| 3| 6| 7| 9| 7| 7| 5| 3| 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|             
   B6C3F1 MICE 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  M  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                                          |             
      Clear Cell Focus                     |                                                                         X|             
      Eosinophilic Focus                   | X              3                                               X         |             
      Necrosis                             |                                                                          |             
      Tension Lipidosis                    |                                                                          |             
      Centrilobular, Necrosis              |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                      +  +        +  +                                   +|             
      Fat, Necrosis                        |                         2           2                                   2|             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                    1                     |             
      Basophilic Focus                     |                                                                          |             
      Cyst                                 |                                     4                                    |             
      Inflammation, Chronic Active         |                                                                          |             
      Lipomatosis                          |             2                       4                                    |             
      Thrombosis                           |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Squamous                |                                                                          |             
      Inflammation, Chronic Active         |             2                                                            |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                           1  1                 1     2  1|             
      Atrium, Thrombosis                   |                                                                      3   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |    2                                                                     |             
      Degeneration, Fatty                  |                                                                          |             
      Hyperplasia                          |                                              2                          1|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |             2           1                                      1     1   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 6| 6| 7| 7| 6| 7| 7| 0| 7| 0| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 0| 9| 3| 4| 2| 4| 3| 3| 9| 3| 2| 7| 3| 6| 3| 3| 3| 8| 3|             
                                           | 6| 6| 1| 6| 6| 6| 1| 6| 5| 6| 3| 6| 5| 7| 1| 7| 3| 6| 7| 9| 7| 7| 5| 3| 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|             
   B6C3F1 MICE 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  M  I  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |       2     2     2     2  3  3        2                       3        3|             
      Pars Intermedia, Hypertrophy         |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |    1  1  2     1  1                 2        1  2                    1  1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |          3        3                 3                       1  1        1|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Hydrometra                           |          4     2                                                         |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +                                                  +                 +|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  M  M  +  +  +|             
      Hemorrhage                           |                      3                                                   |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | M  +  +  +  +  +  M  M  +  +  +  +  +  M  +  M  +  +  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  I  +  +  +  A  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  M  +  +  +  +  +  M  +  +  +  +  +  M  M  +  +  +  M  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Congestion                           |                                              4                           |             
      Hematopoietic Cell Proliferation     |             2        3        2  4  3           4  4  4     2        2   |             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  M  +  +  +  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |       3                                                                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 5| 7| 6| 6| 6| 7| 7| 6| 7| 7| 0| 7| 0| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 0| 9| 3| 4| 2| 4| 3| 3| 9| 3| 2| 7| 3| 6| 3| 3| 3| 8| 3|             
                                           | 6| 6| 1| 6| 6| 6| 1| 6| 5| 6| 3| 6| 5| 7| 1| 7| 3| 6| 7| 9| 7| 7| 5| 3| 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|             
   B6C3F1 MICE 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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Congestion, Chronic                  |                                                                      3   |             
      Hemorrhage                           |                                                                          |             
      Inflammation, Suppurative            |                                           2                              |             
      Alveolar Epithelium, Hyperplasia     |                                                                1         |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                          |             
      Bronchiole, Hyperplasia              |                                                 3                        |             
      Interstitium, Fibrosis               |                                                                      2   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                          2               |             
      Olfactory Epithelium, Degeneration   |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                +         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Amyloid Deposition                   |                                           4                              |             
      Cyst                                 |                                                       2                  |             
      Infarct                              |                                                                      2   |             
      Nephropathy                          | 2  1  1  1  1           1  1        1  1        1     3     2        3  1|             
      Pelvis, Inflammation, Acute          |                                                       2                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 6| 6| 5| 7| 7| 7| 5| 6| 7| 7| 7| 7| 7| 6| 7| 7| 6| 3| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3| 3| 4| 8| 3| 3| 3| 3| 3| 1| 3| 3| 9| 4| 1|            |
                                           | 7| 6| 5| 5| 5| 0| 7| 9| 3| 7| 7| 7| 3| 6| 5| 6| 6| 6| 7| 1| 6| 6| 5| 4| 2|      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     |
   B6C3F1 MICE 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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  M  A  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia, Lymphoid                |             3                                                            |      1  3.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Basophilic Focus                     |                X                                                         |      1     |
      Clear Cell Focus                     |                                                                          |      1     |
      Eosinophilic Focus                   |       X                                               X     X            |      6  3.0|
      Necrosis                             |                4        3           4        1                           |      4  3.0|
      Tension Lipidosis                    |          X        X  X                                                   |      3     |
      Centrilobular, Necrosis              | 4                                                                        |      1  4.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |       +     +                                                     +      |   8        |
      Fat, Necrosis                        |       2     2                                                     2      |      6  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  1.0|
      Basophilic Focus                     |                                     X                                    |      1     |
      Cyst                                 |          4                                                               |      2  4.0|
      Inflammation, Chronic Active         |                                                                   3      |      1  3.0|
      Lipomatosis                          |          4     3                                                         |      4  3.3|
      Thrombosis                           |                                                                   4      |      1  4.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Squamous                |                                                                         2|      1  2.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |             1              1        1     1                              |      9  1.1|
      Atrium, Thrombosis                   |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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   5                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 6| 6| 5| 7| 7| 7| 5| 6| 7| 7| 7| 7| 7| 6| 7| 7| 6| 3| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3| 3| 4| 8| 3| 3| 3| 3| 3| 1| 3| 3| 9| 4| 1|            |
                                           | 7| 6| 5| 5| 5| 0| 7| 9| 3| 7| 7| 7| 3| 6| 5| 6| 6| 6| 7| 1| 6| 6| 5| 4| 2|      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     |
   B6C3F1 MICE 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Degeneration, Fatty                  |          2                                                           1   |      2  1.5|
      Hyperplasia                          |    1                 1                       2                           |      5  1.4|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                              2                           |      5  1.4|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pars Distalis, Hyperplasia           | 2     3  3        1  1           2        2  3  2           2            |     19  2.3|
      Pars Intermedia, Hypertrophy         |                                                                   3      |      1  3.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |          1                 1  1  2     3     2  1                 2      |     18  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  M  +  M  +  +  +  +  I  +  M  +  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |          3  2           1     2           1     3  2                     |     13  2.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |             3     1                                                      |      2  2.0|
      Hydrometra                           |                            3           3                                 |      4  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                         +                                +               |   5        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|  42        |
      Hemorrhage                           |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  M  +  +  M  +  +  M  M  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  M  +  M  M  M  +  +  M  +  +  +  +  M  +  +  +  +  +  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Congestion                           |                                                                          |      1  4.0|
      Hematopoietic Cell Proliferation     |                                     3                                    |     11  3.0|
      Hyperplasia, Lymphoid                |                            2                          2                  |      2  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  M  +  +  +  +  +  M  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|  41        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  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   6                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 7| 7| 7| 6| 6| 5| 7| 7| 7| 5| 6| 7| 7| 7| 7| 7| 6| 7| 7| 6| 3| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 0| 5| 3| 3| 3| 3| 3| 4| 8| 3| 3| 3| 3| 3| 1| 3| 3| 9| 4| 1|            |
                                           | 7| 6| 5| 5| 5| 0| 7| 9| 3| 7| 7| 7| 3| 6| 5| 6| 6| 6| 7| 1| 6| 6| 5| 4| 2|      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     |
   B6C3F1 MICE 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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Congestion, Chronic                  |                                                                          |      1  3.0|
      Hemorrhage                           |                                        2                                 |      1  2.0|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |             1                                         3                  |      3  1.7|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                      1                                      1            |      2  1.0|
      Bronchiole, Hyperplasia              |                                                                          |      1  3.0|
      Interstitium, Fibrosis               |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Olfactory Epithelium, Degeneration   |                   1                                                      |      1  1.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                    +     +               |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Amyloid Deposition                   |                      2                                                   |      2  3.0|
      Cyst                                 |                                                                          |      1  2.0|
      Infarct                              |                                                                          |      1  2.0|
      Nephropathy                          | 3  1  1        2  1  2     1                                   2        1|     23  1.5|
      Pelvis, Inflammation, Acute          |                                                                          |      1  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   7                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 0| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 9| 0| 3| 3| 3| 3| 1| 3| 3| 8| 1| 3| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 3| 3|             
                                           | 7| 3| 2| 6| 6| 1| 7| 1| 6| 6| 1| 2| 7| 6| 6| 7| 6| 6| 5| 3| 1| 5| 7| 5| 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|             
   B6C3F1 MICE 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | M  A  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Hyperplasia                          |       2                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  A  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                                          |             
      Cyst                                 | 2                                                                        |             
      Eosinophilic Focus                   |          X        X     X                          X        X           X|             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Necrosis                             |                            2                                             |             
      Thrombosis                           |                                                                          |             
      Centrilobular, Necrosis              |                                  2                                       |             
                                            __________________________________________________________________________|             
   Mesentery                               |                         +                                               +|             
      Fat, Necrosis                        |                         2                                               2|             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Lipomatosis                          |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Squamous                |                                                                      2   |             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1                          1     1  1                       1     1      |             
      Artery, Mineralization               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Fatty                  | 1                          2                                             |             
      Hyperplasia                          | 2                                                           2     2      |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                  2     1                                 |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           | 3     3  2                          1  2        2  1                     |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   8                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 0| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 9| 0| 3| 3| 3| 3| 1| 3| 3| 8| 1| 3| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 3| 3|             
                                           | 7| 3| 2| 6| 6| 1| 7| 1| 6| 6| 1| 2| 7| 6| 6| 7| 6| 6| 5| 3| 1| 5| 7| 5| 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|             
   B6C3F1 MICE 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1     1  1  1  1           2        1  1  1  1     1  1     1     1     1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | M  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  I  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                     2                                    |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                   2        1     2           3     4     2               |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hydrometra                           |                                  4                                       |             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  M  +  M  M  M  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  M  +  +  +  M  +  M  +  +  +  +  +  +  +  +  M  +  M  M  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | M  +  M  +  M  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  M  M  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |    4                             4                                       |             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fracture                             |                                                          X               |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                          +               |             
      Hemorrhage                           |                                                          2               |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   9                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 0| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 9| 0| 3| 3| 3| 3| 1| 3| 3| 8| 1| 3| 3| 3| 3| 3| 3| 3| 0| 9| 3| 3| 3| 3|             
                                           | 7| 3| 2| 6| 6| 1| 7| 1| 6| 6| 1| 2| 7| 6| 6| 7| 6| 6| 5| 3| 1| 5| 7| 5| 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|             
   B6C3F1 MICE 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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Thrombosis                           |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                                                                         1|             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Thrombosis                           |                                                                          |             
      Olfactory Epithelium, Degeneration   |                               2                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                   +                                         +            |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Amyloid Deposition                   |                                                                          |             
      Infarct                              |                                                                          |             
      Metaplasia, Osseous                  |          3                                                               |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 1     1  2                    2  3  1                       1  1  1      |             
      Renal Tubule, Necrosis               |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  10                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 6| 7| 7| 6| 7| 6| 6| 5| 7| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 9| 1| 3| 3| 2| 3| 3| 6| 2| 3| 3| 9| 3| 3| 4| 3| 3| 3| 3| 3| 8| 3| 2|            |
                                           | 5| 6| 5| 1| 6| 6| 1| 7| 6| 3| 7| 5| 7| 5| 7| 6| 6| 7| 7| 7| 5| 5| 6| 7| 3|      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     |
   B6C3F1 MICE 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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  44        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Basophilic Focus                     |       X  X                                X                              |      3     |
      Cyst                                 |                                                                          |      1  2.0|
      Eosinophilic Focus                   |       X                                                                  |      7     |
      Hematopoietic Cell Proliferation     |                                                                         3|      1  3.0|
      Necrosis                             |                            2           3                                 |      3  2.3|
      Thrombosis                           |                         3                                                |      1  3.0|
      Centrilobular, Necrosis              |                         3                                                |      2  2.5|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   2        |
      Fat, Necrosis                        |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                                                 3                        |      1  3.0|
      Lipomatosis                          |                                              2                           |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Squamous                |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |                                        1                                 |      1  1.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Mineralization                       |                         3                                                |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    1  1     1     2                       1                       2      |     12  1.2|
      Artery, Mineralization               |                                        2                                 |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Degeneration, Fatty                  |                                                                          |      2  1.5|
      Hyperplasia                          |                                                                          |      3  2.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  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  11                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 6| 7| 7| 6| 7| 6| 6| 5| 7| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 9| 1| 3| 3| 2| 3| 3| 6| 2| 3| 3| 9| 3| 3| 4| 3| 3| 3| 3| 3| 8| 3| 2|            |
                                           | 5| 6| 5| 1| 6| 6| 1| 7| 6| 3| 7| 5| 7| 5| 7| 6| 6| 7| 7| 7| 5| 5| 6| 7| 3|      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     |
   B6C3F1 MICE 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia                          |                                                             2            |      3  1.7|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  M  +  +  +  M  +  M  +  +  M|  40        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  49        |
      Pars Distalis, Hyperplasia           |       2  2     3     2        2  2  3  2  3  2     3  3     2  2  1     3|     23  2.2|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 1                    2              2  1  2  1     2  2  2  1           1|     26  1.3|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  M  M  +  I  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  M  +  M|  39        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 | 2     2           1              2  2  2  2              3        2      |     15  2.1|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hydrometra                           |    3     2                                                           3   |      4  3.0|
      Inflammation, Suppurative            |                            3                                             |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +  +                 +     +                          +            |   5        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  +  +  +  +  M  M  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  M  +  +  M  M  +  +  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  M  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     |       3                 4     3        2     2  4        2  3     3      |     11  3.1|
      Hyperplasia, Lymphoid                |             2                                         3                  |      2  2.5|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  M  +  M  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  43        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fracture                             |                                                                          |      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: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 5| 6| 7| 7| 6| 7| 6| 6| 5| 7| 7| 6| 7| 7| 5| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 9| 1| 3| 3| 2| 3| 3| 6| 2| 3| 3| 9| 3| 3| 4| 3| 3| 3| 3| 3| 8| 3| 2|            |
                                           | 5| 6| 5| 1| 6| 6| 1| 7| 6| 3| 7| 5| 7| 5| 7| 6| 6| 7| 7| 7| 5| 5| 6| 7| 3|      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     |
   B6C3F1 MICE 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|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Hemorrhage                           |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                   2                                                      |      1  2.0|
      Thrombosis                           |          3                                                               |      1  3.0|
      Alveolar Epithelium, Hyperplasia     |          3                          2                                    |      3  2.0|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                   2           1                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                            3                                             |      1  3.0|
      Thrombosis                           |                            4                                             |      1  4.0|
      Olfactory Epithelium, Degeneration   |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                             +     +      |   4        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Amyloid Deposition                   |                   3                                                      |      1  3.0|
      Infarct                              |             2           2                                                |      2  2.0|
      Metaplasia, Osseous                  |                                                                          |      1  3.0|
      Mineralization                       |                                        2                                 |      1  2.0|
      Nephropathy                          | 1  1     1  2     4  1                 3     1  3              1        1|     20  1.6|
      Renal Tubule, Necrosis               |                                        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  13                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 7| 7| 7| 6| 6| 5| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 6| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 8| 3| 3| 3| 3| 6| 1| 7| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 0| 3| 3| 3| 3| 3|             
                                           | 1| 7| 6| 6| 6| 5| 1| 7| 4| 6| 6| 6| 7| 6| 6| 7| 5| 3| 7| 9| 6| 5| 6| 7| 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|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | A  M  +  +  +  +  A  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                   2      |             
      Basophilic Focus                     |                                                                          |             
      Clear Cell Focus                     |                                                                          |             
      Cyst                                 |                2                                                         |             
      Eosinophilic Focus                   |          X  X                                                            |             
      Mixed Cell Focus                     |                                           X                              |             
      Necrosis                             |                                                                          |             
      Tension Lipidosis                    |                                                                          |             
      Centrilobular, Necrosis              |                      3  1                                                |             
                                            __________________________________________________________________________|             
   Mesentery                               |                         +                                            +   |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hypertrophy                          |                                                                         2|             
      Inflammation, Chronic Active         |                                                                          |             
      Lipomatosis                          |                                                                   1      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                      2   |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                +                                                         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                     1     1                       1      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Fatty                  |                                                                          |             
      Hypertrophy                          |                                                                      1   |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                   2      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  +  M  +  +  +  +  M  M  +  +  +  +  +  M  M  +  +  +  M  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  14                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 7| 7| 7| 6| 6| 5| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 6| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 8| 3| 3| 3| 3| 6| 1| 7| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 0| 3| 3| 3| 3| 3|             
                                           | 1| 7| 6| 6| 6| 5| 1| 7| 4| 6| 6| 6| 7| 6| 6| 7| 5| 3| 7| 9| 6| 5| 6| 7| 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|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |          1                 3  2  2     2  1     2                    1   |             
      Pars Intermedia, Hyperplasia         |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |          2  1  1     1  1  1  1  1  2  1  1  1  1                       1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | M  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Cyst                                 |                2                             3                          2|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                      4                                                   |             
      Hydrometra                           |             3                                                  3        4|             
                                            __________________________________________________________________________|             
   Vagina                                  |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              | +                                                        +               |             
      Lumbar, Ectasia                      |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | M  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  +  +  +  M  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |                                                                         2|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  M  M  +  M  +  +  M  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     | 4     3                 3           3                                4   |             
      Hyperplasia, Lymphoid                |                               2                                   2      |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +  M  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  M  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Subcutaneous Tissue, Angiectasis     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperostosis                         |                                                 1                        |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  15                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 7| 7| 7| 6| 6| 5| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 6| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 8| 3| 3| 3| 3| 6| 1| 7| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 0| 3| 3| 3| 3| 3|             
                                           | 1| 7| 6| 6| 6| 5| 1| 7| 4| 6| 6| 6| 7| 6| 6| 7| 5| 3| 7| 9| 6| 5| 6| 7| 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|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 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|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |          1                                                               |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Olfactory Epithelium, Degeneration,  |                                                                          |             
           Hyaline                         |                2                                                         |             
      Olfactory Epithelium, Degeneration   | 1           1        1  1  1  1           1        1  1  1        2  1   |             
      Olfactory Epithelium, Necrosis       |                   4                                                      |             
      Respiratory Epithelium, Necrosis     |                   2                                                      |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Cyst                                 |                                                                          |             
      Metaplasia, Osseous                  |       2                                                           1      |             
      Mineralization                       |                      2                                                   |             
      Nephropathy                          |          1  1              1        2  1  1  1  1                 1     1|             
      Pelvis, Dilatation                   |                                                                          |             
      Renal Tubule, Necrosis               |                      3                                                   |             
                                            __________________________________________________________________________|             
   Ureter                                  |          +                                                               |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  16                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 6| 7| 7| 5| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 4| 3| 3| 3| 3| 3| 3| 5| 3|            |
                                           | 7| 7| 6| 6| 3| 5| 5| 7| 7| 7| 6| 6| 6| 6| 7| 3| 5| 6| 5| 6| 1| 5| 6| 4| 7|      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     |
   B6C3F1 MICE 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     |
    1000 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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Hyperplasia, Lymphoid                |                                  3                                       |      1  3.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                             2            |      2  2.0|
      Basophilic Focus                     |                         X                 X                              |      2     |
      Clear Cell Focus                     |                                        X                          X      |      2     |
      Cyst                                 |                                                                          |      1  2.0|
      Eosinophilic Focus                   |                X     X                                         X         |      5     |
      Mixed Cell Focus                     |                                                                          |      1     |
      Necrosis                             |                                                             1            |      1  1.0|
      Tension Lipidosis                    |                      X                          X                        |      2     |
      Centrilobular, Necrosis              |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                              +                       +   |   4        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hypertrophy                          |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |                                                                      3   |      1  3.0|
      Lipomatosis                          |                                                                3     3   |      3  2.3|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                 1                        |      1  1.0|
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1     1  1     2     1     1        1                                    |     10  1.1|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration, Fatty                  |       3                                                                  |      1  3.0|
      Hypertrophy                          |                                                                          |      1  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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  17                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 6| 7| 7| 5| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 4| 3| 3| 3| 3| 3| 3| 5| 3|            |
                                           | 7| 7| 6| 6| 3| 5| 5| 7| 7| 7| 6| 6| 6| 6| 7| 3| 5| 6| 5| 6| 1| 5| 6| 4| 7|      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     |
   B6C3F1 MICE 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     |
    1000 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Necrosis                             |                         3                                                |      1  3.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                         2|      2  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +|  40        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pars Distalis, Hyperplasia           |    3  1  2        2  2        1     3  2     1  3  3  2           3  1  1|     23  1.9|
      Pars Intermedia, Hyperplasia         |                               2                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |    1           2  1        2     2                 1     1  1     3     1|     24  1.3|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | M  +  +  +  M  M  +  +  +  +  +  +  +  M  +  +  M  +  +  +  M  +  +  +  +|  40        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                   2     3|      2  2.5|
      Cyst                                 | 2     1           3  3     3  3  4     2           2  2              2   |     14  2.4|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      1  4.0|
      Hydrometra                           |    3        3                                   4                        |      6  3.3|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +                 +                                                |   4        |
      Lumbar, Ectasia                      |       4                                                                  |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  M  +  +  +  M  +|  42        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M|  47        |
      Necrosis                             |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  M  +|  38        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |             3        4           2           3              4        3   |     11  3.3|
      Hyperplasia, Lymphoid                | 3                                                                        |      3  2.3|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +|  41        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY 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  18                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 6| 7| 7| 5| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 4| 3| 3| 3| 3| 3| 3| 5| 3|            |
                                           | 7| 7| 6| 6| 3| 5| 5| 7| 7| 7| 6| 6| 6| 6| 7| 3| 5| 6| 5| 6| 1| 5| 6| 4| 7|      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     |
   B6C3F1 MICE 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     |
    1000 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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Subcutaneous Tissue, Angiectasis     |                               2                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperostosis                         |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                             +            |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                                                                      2   |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                              1                           |      1  1.0|
      Olfactory Epithelium, Degeneration,  |                                                                          |            |
           Hyaline                         |                                                                          |      1  2.0|
      Olfactory Epithelium, Degeneration   |    1  1     1     2  1  1  1     2           1  1  1     1  1     1  1   |     27  1.1|
      Olfactory Epithelium, Necrosis       |                                                 2                        |      2  3.0|
      Respiratory Epithelium, Necrosis     |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                +              +                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                      3   |      1  3.0|
      Cyst                                 |                                     2                                    |      1  2.0|
      Metaplasia, Osseous                  |                                                 1     2                  |      4  1.5|
      Mineralization                       |                                                                      1   |      2  1.5|
      Nephropathy                          |          1        1        1     2                 1                     |     15  1.1|
      Pelvis, Dilatation                   |                                                                      4   |      1  4.0|
      Renal Tubule, Necrosis               |                                                                          |      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: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 7| 7| 6| 7| 7| 5| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 4| 3| 3| 3| 3| 3| 3| 5| 3|            |
                                           | 7| 7| 6| 6| 3| 5| 5| 7| 7| 7| 6| 6| 6| 6| 7| 3| 5| 6| 5| 6| 1| 5| 6| 4| 7|      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     |
   B6C3F1 MICE 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     |
    1000 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|            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ureter                                  |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   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  20                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 3| 3| 5| 3| 3| 3| 6| 3| 3| 3| 5| 3| 3| 5| 3| 3| 3| 3| 5| 3| 3| 3| 3|             
                                           | 2| 1| 7| 6| 2| 7| 5| 5| 5| 6| 7| 6| 3| 7| 6| 3| 7| 5| 7| 7| 3| 6| 6| 6| 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|             
   B6C3F1 MICE 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|             
    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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                2                                                         |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     | X                                                        X               |             
      Eosinophilic Focus                   |                                                                      X   |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Cyst                                 |                                                                          |             
      Hypertrophy                          |                                                                          |             
      Inflammation, Chronic Active         |                                                                          |             
      Lipomatosis                          |                            4                                             |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         |                                                                          |             
      Hyperplasia, Squamous                |                1              1                                         2|             
      Inflammation, Chronic Active         |                                              1                    2      |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Developmental Malformation           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 2              2              2  1        1           1                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Fatty                  |                                                                      3   |             
      Hyperplasia                          |                                                                          |             
      Hypertrophy                          |                                                       1                  |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  21                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 3| 3| 5| 3| 3| 3| 6| 3| 3| 3| 5| 3| 3| 5| 3| 3| 3| 3| 5| 3| 3| 3| 3|             
                                           | 2| 1| 7| 6| 2| 7| 5| 5| 5| 6| 7| 6| 3| 7| 6| 3| 7| 5| 7| 7| 3| 6| 6| 6| 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|             
   B6C3F1 MICE 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|             
    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|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  M|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |                   2  2     2        2                                3   |             
      Pars Intermedia, Hypertrophy         |                                                          2               |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1  1  2     1  3  2  2     1  2  1  3  2     1  1     2  2     1  1  3  1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 2     4        4     1     2                 1     4           1     3  2|             
      Hyperplasia                          |                                                          2               |             
      Interstitial Cell, Hyperplasia       |                                                                   2      |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Hydrometra                           |                                  3                 3           3         |             
      Thrombosis                           |    4                                                                     |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                               +        +                                 |             
      Lumbar, Hemorrhage                   |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  M  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |    3     3     3                          2                       2  3   |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Subcutaneous Tissue, Necrosis        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  22                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 6| 7| 7| 7| 6| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 3| 3| 5| 3| 3| 3| 6| 3| 3| 3| 5| 3| 3| 5| 3| 3| 3| 3| 5| 3| 3| 3| 3|             
                                           | 2| 1| 7| 6| 2| 7| 5| 5| 5| 6| 7| 6| 3| 7| 6| 3| 7| 5| 7| 7| 3| 6| 6| 6| 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|             
   B6C3F1 MICE 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|             
    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|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Meninges, Infiltration Cellular,     |                                                                          |             
           Mononuclear Cell                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epiglottis, Hyperplasia              |             1                                                            |             
      Epiglottis, Metaplasia, Squamous     |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Olfactory Epithelium, Degeneration   | 2  2  2  1  1  2  1  2  2     2  2  1  2  2  2  2  1  2  1  2  1  1  1  1|             
      Olfactory Epithelium, Necrosis       |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                      +                                                   |             
      Cornea, Mineralization               |                                                                          |             
      Lens, Mineralization                 |                      3                                                   |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                         +|             
      Hyperplasia                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infarct                              |                                                                          |             
      Metaplasia, Osseous                  |                                                                      1   |             
      Nephropathy                          |       1  1     2  1        1     1  1  1  2  2  2     1  1        2     1|             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  23                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 6| 6| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 8| 1| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 5|            |
                                           | 5| 5| 7| 5| 6| 2| 1| 6| 5| 5| 6| 6| 7| 6| 6| 6| 7| 6| 7| 3| 6| 6| 5| 6| 3|      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     |
   B6C3F1 MICE 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   | 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|      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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  47        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                                                         X|      3     |
      Eosinophilic Focus                   |                X           X                 X                           |      4     |
      Hematopoietic Cell Proliferation     |                                                          2               |      1  2.0|
      Necrosis                             |                                                          2               |      1  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               | +           +                                            +               |   3        |
      Hemorrhage                           |             2                                                            |      1  2.0|
      Fat, Necrosis                        | 2                                                        4               |      2  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |          3                                                               |      1  3.0|
      Cyst                                 |          4                                                               |      1  4.0|
      Hypertrophy                          |                                                                      1   |      1  1.0|
      Inflammation, Chronic Active         |          2                                               3               |      2  2.5|
      Lipomatosis                          |                   2                             4                        |      3  3.3|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Diverticulum                         |                               X                                          |      1     |
      Hyperplasia, Squamous                |                                                                          |      3  1.3|
      Inflammation, Chronic Active         |                                                          2               |      3  1.7|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                         +                                                |   1        |
      Developmental Malformation           |                         X                                                |      1     |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |                                                 1                        |      7  1.4|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration, Fatty                  |                                                                          |      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  24                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 6| 6| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 8| 1| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 5|            |
                                           | 5| 5| 7| 5| 6| 2| 1| 6| 5| 5| 6| 6| 7| 6| 6| 6| 7| 6| 7| 3| 6| 6| 5| 6| 3|      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     |
   B6C3F1 MICE 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   | 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|      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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia                          |                                     1                                    |      1  1.0|
      Hypertrophy                          |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                      1                                                   |      1  1.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  M  M  +  +  +  M  +  +  M  +  M  +  +  +  +  +  +  +  +  +|  40        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Hyperplasia           |       2        2  2  2           2           3  1     2     2  2  2     2|     17  2.1|
      Pars Intermedia, Hypertrophy         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 2  1  3        2     1        1              2  2  1  1     1        2   |     32  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  M  +  +  M  M  +  +  +  +  +  M  +  I  +  +  +  +  +  M  +  +  M  +  +|  40        |
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |       2  2  2                 3  3  4  4              1                  |     18  2.5|
      Hyperplasia                          |                                                                          |      1  2.0|
      Interstitial Cell, Hyperplasia       |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                3         |      1  3.0|
      Hydrometra                           | 2  3                                         3                       3   |      7  2.9|
      Thrombosis                           |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +                                                           +            |   4        |
      Lumbar, Hemorrhage                   | 2                                                                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  M|  44        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Angiectasis                          |                                                                   2      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  +  +  +  M  +  +  M  +  +  M  +  +  M  +  +  M  +  +  M  +  +  M  +  +|  38        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |          4        4                                      4               |      9  3.1|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  M  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  43        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY 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  25                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 4| 7| 6| 6| 7| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 8| 1| 3| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 5|            |
                                           | 5| 5| 7| 5| 6| 2| 1| 6| 5| 5| 6| 6| 7| 6| 6| 6| 7| 6| 7| 3| 6| 6| 5| 6| 3|      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     |
   B6C3F1 MICE 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   | 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|      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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                          4               |      1  4.0|
      Subcutaneous Tissue, Necrosis        |                                                          4               |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Meninges, Infiltration Cellular,     |                                                                          |            |
           Mononuclear Cell                |                                                                2         |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epiglottis, Hyperplasia              |                                                                          |      1  1.0|
      Epiglottis, Metaplasia, Squamous     |                                                                   1      |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                   2                                                      |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                     3                                    |      1  3.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Olfactory Epithelium, Degeneration   | 2  2  1  2  2  1  2  2  1  2  2  1  1  2  2  1  1  1  2  1  1  1  2  2  2|     49  1.6|
      Olfactory Epithelium, Necrosis       |                                                                      1   |      1  1.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |    +                                                           +         |   3        |
      Cornea, Mineralization               |    3                                                           3         |      2  3.0|
      Lens, Mineralization                 |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                      +                                                   |   2        |
      Hyperplasia                          |                      2                                                   |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infarct                              |       2                                         1                        |      2  1.5|
      Metaplasia, Osseous                  |                                                                          |      1  1.0|
      Nephropathy                          |       1     1           1           1                    3               |     20  1.4|
                                            __________________________________________________________________________|____________|
   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  26                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 3| 3| 3| 6| 3| 3| 3| 3| 3| 5| 3| 3| 3|             
                                           | 4| 5| 3| 4| 4| 3| 5| 3| 3| 4| 3| 3| 5| 5| 4| 4| 3| 3| 3| 4| 3| 9| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +     +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |       X                                      X                    3      |             
      Clear Cell Focus                     |                                                                          |             
      Eosinophilic Focus                   |                                           X        X  X                  |             
      Infarct, Focal                       |                                                                          |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                      1   |             
      Inflammation, Chronic Active         |                                                                   2      |             
      Lipomatosis                          |    1                                                                     |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         | X                                                                        |             
      Inflammation, Chronic Active         |                                     2                                    |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                1  1     1     1  1     1     2           1     2  1      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                        2                                 |             
      Hyperplasia                          | 3  2  2                       1        2                          2  2   |             
      Hypertrophy                          |    2  2  1     2  1     2  1     1  1     1  1  1     1  2  2        1  2|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                   2      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  27                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 3| 3| 3| 6| 3| 3| 3| 3| 3| 5| 3| 3| 3|             
                                           | 4| 5| 3| 4| 4| 3| 5| 3| 3| 4| 3| 3| 5| 5| 4| 4| 3| 3| 3| 4| 3| 9| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    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                   |                                                                          |             
                                           |                                                                          |             
      Follicular Cell, Hyperplasia         |    1  1     1           1           2           1           2  2         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Granuloma Sperm                      |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                               3        3                                 |             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                   4      |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                   3                                                      |             
      Inflammation, Chronic Active         |                                                                      2   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Degeneration                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  +  +  M  +  +  +  +  +  M  M  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  M  M  +  +  +  +  M  +  M  +  M  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | M  +  +  +  +  M  M  M  +  M  M  +  M  +  M  +  M  +  M  M  M  M  M  M  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                   2                 2                             2      |             
      Hyperplasia, Lymphoid                |                                           2                              |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                   2      |             
      Prepuce, Inflammation, Acute         |                                                                3         |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  28                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 8| 3| 3| 3| 3| 3| 3| 3| 3| 6| 3| 3| 3| 3| 3| 5| 3| 3| 3|             
                                           | 4| 5| 3| 4| 4| 3| 5| 3| 3| 4| 3| 3| 5| 5| 4| 4| 3| 3| 3| 4| 3| 9| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Epiglottis, Hyperplasia              |                                                                          |             
      Epiglottis, Metaplasia, Squamous     |             1                                                            |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                   2                                                      |             
      Pigmentation                         |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                      3                                                   |             
      Artery, Mediastinum, Mineralization  |                   3                                                      |             
      Bronchiole, Hyperplasia              | 2                                                                        |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nasolacrimal Duct, Hyperplasia       |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                    +                     |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                            2                                2           2|             
      Infarct                              |                                     2  2                                 |             
      Mineralization                       |                   2                                                      |             
      Nephropathy                          | 3  1  2  2  2  3     2  1  2  2  1  2  2  2  2  2  2  2  2  2        2  2|             
      Pelvis, Inflammation, Acute          |                   2                                               3      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                   3      |             
      Mineralization                       |                   2                                                      |             
      Transitional Epithelium, Hyperplasia |                                                                   3      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  29                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3| 3| 8| 3|            |
                                           | 4| 9| 9| 3| 3| 3| 4| 4| 5| 3| 4| 4| 3| 4| 0| 3| 4| 6| 3| 3| 9| 5| 4| 2| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  47        |
      Hyperplasia                          |                                     1                                    |      1  1.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Basophilic Focus                     | X                                                                        |      4  3.0|
      Clear Cell Focus                     |       X                                      X                           |      2     |
      Eosinophilic Focus                   |                                                                          |      3     |
      Infarct, Focal                       |                                                             4            |      1  4.0|
      Necrosis                             |                                                          2               |      1  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                       +                  |   1        |
      Fat, Necrosis                        |                                                       2                  |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  1.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
      Lipomatosis                          |          1                                                               |      2  1.0|
      Necrosis                             |                         4                                                |      1  4.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Diverticulum                         |                                                                          |      1     |
      Inflammation, Chronic Active         |                                           2                              |      2  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1        1     1  1  1     1  1     1  1     1     1  1     1     1  1  1|     26  1.1|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  2.0|
      Hyperplasia                          |       2           2  2                 2     2           2        2      |     14  2.0|
      Hypertrophy                          | 2        2  1  2  1  2     2  1              2  1  1  2  2     2  2      |     32  1.5|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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  30                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3| 3| 8| 3|            |
                                           | 4| 9| 9| 3| 3| 3| 4| 4| 5| 3| 4| 4| 3| 4| 0| 3| 4| 6| 3| 3| 9| 5| 4| 2| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  M  M  +  +  +  +  +  +  +  +  M  I  +  M  +  +  +  +  +  +  +  +  +|  43        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Hyperplasia           |                2                       1                 2               |      3  1.7|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         | 2                                            1                          1|     11  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Granuloma Sperm                      |                                                 3                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                               3  2              3                    2  4|      7  2.9|
      Inflammation, Chronic Active         |             3                                                            |      1  3.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Chronic Active         |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                                                          |      1  3.0|
      Inflammation, Chronic Active         |    2                                                                     |      2  2.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Degeneration                         |                                     2                                    |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  M  +  +  M  +  +  +  M  M  +  +  M  +  M  M  +  +  +  +  +  +  +  M  +|  37        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | M  M  +  M  M  +  M  +  M  +  +  +  M  M  +  M  M  M  M  +  +  M  M  M  M|  27        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  M  M  M  +  +  M  +  +  +  +|  29        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |       4                                3           2        3            |      7  2.6|
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  +  +  M  +  +  +  M  M  M  +  +  +  M  +  M  +  M  +  +|  39        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  49        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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  31                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 6| 7| 7| 7| 7| 7| 4| 7| 7| 7| 7| 7| 5| 7| 7| 6| 7| 7| 6| 7| 7| 6| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3| 3| 8| 3|            |
                                           | 4| 9| 9| 3| 3| 3| 4| 4| 5| 3| 4| 4| 3| 4| 0| 3| 4| 6| 3| 3| 9| 5| 4| 2| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Prepuce, Inflammation, Acute         |    3                                      2                              |      3  2.7|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epiglottis, Hyperplasia              |                         1                                                |      1  1.0|
      Epiglottis, Metaplasia, Squamous     |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                                                                          |      1  2.0|
      Pigmentation                         |                                     2                                    |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |          1                 3                                             |      3  2.3|
      Artery, Mediastinum, Mineralization  |                                                                          |      1  3.0|
      Bronchiole, Hyperplasia              |                                                    2                     |      2  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nasolacrimal Duct, Hyperplasia       |                                                 4                        |      1  4.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                               2                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                               +     +                                    |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      3  2.0|
      Infarct                              |                                                                          |      2  2.0|
      Mineralization                       |                                                                          |      1  2.0|
      Nephropathy                          | 2  2  3  2  2  2  2  1     2  1  2  2  3     2  2  2  2  1  2  1  2  2  1|     45  1.9|
      Pelvis, Inflammation, Acute          |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  3.0|
      Mineralization                       |                                                                          |      1  2.0|
      Transitional Epithelium, Hyperplasia |                                                                          |      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  32                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 6| 7| 6| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 7| 3| 8| 1| 2| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 9| 0| 0| 4| 0| 5| 3| 5| 4| 4| 4| 4| 5| 4| 5| 3| 3| 3| 4| 5| 4| 3| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  M  +  +  A  +  M  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                         1                                            3   |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                            3                                             |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Basophilic Focus                     |          X                                            X                  |             
      Clear Cell Focus                     |                            X                                             |             
      Eosinophilic Focus                   |          X                                X                             X|             
      Mixed Cell Focus                     |                                                                         X|             
      Necrosis                             |                                                                      1   |             
      Centrilobular, Necrosis              |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                +     +                          +                        |             
      Artery, Inflammation                 |                3                                                         |             
      Fat, Necrosis                        |                      2                          2                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
      Lipomatosis                          | 3                                                        2               |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |             1                                                            |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                1         |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Developmental Malformation           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1  1        1  2  1  1        1              2  1     1     1  1  1  1  1|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2        1  1        2                 2        2     2  2     2         |             
      Hypertrophy                          |          1           2  1  2        2     1     1  2  1     2     3  2   |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +  M  +  M  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Hyperplasia           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  33                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 6| 7| 6| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 7| 3| 8| 1| 2| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 9| 0| 0| 4| 0| 5| 3| 5| 4| 4| 4| 4| 5| 4| 5| 3| 3| 3| 4| 5| 4| 3| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |                      1     1           2           2                     |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 4                          3     3     3     3     4                     |             
      Inflammation, Chronic Active         |                                                                         2|             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                   2                                                      |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  M  +  M  +  M  M  +  +  M  +  +  +  M  +  +  M  +  +  M  +  +  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | M  M  +  +  M  +  +  M  +  M  +  M  +  +  M  M  +  +  M  M  M  +  M  M  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  M  M  M  +  +  +  +  +  M  M  +  M  M  M  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |    3  2           3                                                  3   |             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  +  +  +  M  +  +  +  +  +  +  +  M  M  M  M  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                      3   |             
      Necrosis                             |                                                                          |             
      Prepuce, Inflammation, Acute         |       3           4                                            3         |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  34                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 6| 7| 6| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 0| 8| 7| 3| 8| 1| 2| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
                                           | 9| 0| 0| 4| 0| 5| 3| 5| 4| 4| 4| 4| 5| 4| 5| 3| 3| 3| 4| 5| 4| 3| 4| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Epiglottis, Metaplasia, Squamous     |                                                                          |             
      Glands, Inflammation, Suppurative    |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                      2                                                   |             
      Artery, Mediastinum, Mineralization  |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |    +                                                                 +   |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                        1                                 |             
      Infarct                              |                                                                          |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 1  1  1  1  1     1  1  2  2     1  2  2  2     2  1  3  1  1  2  1  2  1|             
      Pelvis, Inflammation, Acute          |       2                                                                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  35                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 3| 4| 3| 1|            |
                                           | 5| 4| 3| 4| 5| 2| 5| 4| 4| 3| 4| 4| 5| 5| 4| 3| 3| 2| 4| 4| 4| 4| 9| 4| 1|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  M  +  +  M  +|  43        |
      Hyperplasia                          |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Fibrosis                             |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |       1                                                                  |      1  1.0|
      Basophilic Focus                     |          X  X  X              X           X                          X   |      8     |
      Clear Cell Focus                     |    X     X        X  X                                X              X   |      7     |
      Eosinophilic Focus                   | X                          X        X                                    |      6     |
      Mixed Cell Focus                     |                                                 X                        |      2     |
      Necrosis                             |                                                                          |      1  1.0|
      Centrilobular, Necrosis              |                2                                                         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   3        |
      Artery, Inflammation                 |                                                                          |      1  3.0|
      Fat, Necrosis                        |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Lipomatosis                          |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                      2   |      2  1.5|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |             +              +  +                                          |   3        |
      Developmental Malformation           |             X              X  X                                          |      3     |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1  1  2     1  2     1  2  1     1  1        2     1     1     1        1|     30  1.2|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |    2  1              2  2  1  2     2           2     2  2           2  1|     21  1.8|
      Hypertrophy                          | 2        1     1           1  2              2           2  2  2         |     21  1.7|
 __________________________________________________________________________________________________________________________________ 
  * : 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  36                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 3| 4| 3| 1|            |
                                           | 5| 4| 3| 4| 5| 2| 5| 4| 4| 3| 4| 4| 5| 5| 4| 3| 3| 2| 4| 4| 4| 4| 9| 4| 1|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  M  M  +  +  M  +  +  +  +|  41        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +|  47        |
      Pars Distalis, Hyperplasia           |                1              2                       1                  |      3  1.3|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |    1     2  1        1           1                 1           2         |     11  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                               3        3              4                  |      9  3.3|
      Inflammation, Chronic Active         |                                  1                                       |      2  1.5|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                    3                     |      1  3.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  M  +  M  M  +  +  +  M  M  +  +  M  M  +  +  +  +  +  +  +  +  +  +|  34        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  M  M  M  +  M  +  +  +  M  +  M  M  M  +  +  M  +  +  +  +  +  M  +  M|  25        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  +  M  +  M  +  +  +  M  +  +  +  M  +  +  +  M  M  +  M|  34        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                2        3           2                                    |      7  2.6|
      Hyperplasia, Lymphoid                |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  M  +  +  +  M  +  M  +  +  +  +  M  +  +  +  +  +  +  +|  39        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                1                                                         |      2  2.0|
      Necrosis                             |                                     2                                    |      1  2.0|
      Prepuce, Inflammation, Acute         |                                                    3                     |      4  3.3|
 __________________________________________________________________________________________________________________________________ 
  * : 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  37                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3| 3| 4| 3| 1|            |
                                           | 5| 4| 3| 4| 5| 2| 5| 4| 4| 3| 4| 4| 5| 5| 4| 3| 3| 2| 4| 4| 4| 4| 9| 4| 1|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                                                                         3|      1  3.0|
      Epiglottis, Metaplasia, Squamous     |                                        1                                 |      1  1.0|
      Glands, Inflammation, Suppurative    |                               1                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                         3|      1  3.0|
      Alveolar Epithelium, Hyperplasia     |                               1              1                           |      3  1.3|
      Artery, Mediastinum, Mineralization  |                                                                         2|      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                        2                                2|      2  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                         2|      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                   2                          2                           |      3  1.7|
      Infarct                              |    1                                                                     |      1  1.0|
      Mineralization                       |                                                                         2|      1  2.0|
      Nephropathy                          | 1     4  1  2  1  2  2  3  2  1  1  2  1  1  1  1  1  1  2  2  2  2  2  3|     46  1.6|
      Pelvis, Inflammation, Acute          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   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  38                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 7| 7| 7| 7| 0| 7| 6| 7| 7| 7| 7| 6| 7| 7| 3| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 2| 3|             
                                           | 2| 3| 1| 5| 4| 4| 4| 3| 3| 3| 3| 9| 3| 4| 4| 5| 0| 4| 3| 9| 4| 5| 5| 9| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    1000 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  M  A  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |             1                                                     2      |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                 X                        |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                                          |             
      Clear Cell Focus                     |                               X     X                 X                  |             
      Degeneration, Fatty                  |                                                                          |             
      Eosinophilic Focus                   |                                                                          |             
      Infarct, Focal                       | 4                                                                        |             
      Necrosis                             |                                                                          |             
      Tension Lipidosis                    |                                                                          |             
      Centrilobular, Necrosis              |                                                                      3   |             
                                            __________________________________________________________________________|             
   Mesentery                               |    +                                            +        +  +            |             
      Fat, Necrosis                        |    2                                            2        1  3            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                              1                           |             
      Lipomatosis                          |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                          3               |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |          1                                                               |             
      Artery, Inflammation                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                      +                                   +               |             
      Developmental Malformation           |                      X                                                   |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 1  1        1     1  1  1     1  1  1  2  1  1  2  1  1     1  1  1      |             
      Mineralization                       |                                                                          |             
      Atrium, Thrombosis                   |                                  2                                       |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    2     3  1                                2  2     2     2     2      |             
      Hypertrophy                          | 1  2     2  2  2  2     1     1        2        2     2        1  1     2|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  39                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 7| 7| 7| 7| 0| 7| 6| 7| 7| 7| 7| 6| 7| 7| 3| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 2| 3|             
                                           | 2| 3| 1| 5| 4| 4| 4| 3| 3| 3| 3| 9| 3| 4| 4| 5| 0| 4| 3| 9| 4| 5| 5| 9| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    1000 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                   |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |                                        2                                 |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                 2                        |             
      Pars Intermedia, Hyperplasia         |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         | 1           1     2                             1  1  2           2     1|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Penis                                   |                                                 +                        |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +|             
      Cyst                                 |                               3  2     4                       2  2      |             
      Inflammation, Chronic Active         |          3  3                                                            |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic Active         |                                                 1                        |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  M  M  +  +  +  +  +  +  +  M  +  M  +  +  M  +  +  M  M  M  +  M  M  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  M  +  +  +  +  M  M  +  +  +  M  +  +  M  +  +  M  +  M  +  M  +  +  M|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  M  M  +  +  M  M  M  +  M  +  +  M  M  +  +  M  M  +  +  +  +  M  M  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Hematopoietic Cell Proliferation     | 2                                      3        2                       3|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  M  +  +  +  +  +  +|             
      Artery, Inflammation                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         | 4                    2                                                   |             
      Prepuce, Inflammation, Acute         | 3                                               3                        |             
      Subcutaneous Tissue, Edema           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  40                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 7| 7| 7| 7| 0| 7| 6| 7| 7| 7| 7| 6| 7| 7| 3| 7| 7| 7| 5| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 3| 3| 3| 5| 3| 3| 3| 2| 3|             
                                           | 2| 3| 1| 5| 4| 4| 4| 3| 3| 3| 3| 9| 3| 4| 4| 5| 0| 4| 3| 9| 4| 5| 5| 9| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    1000 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|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epiglottis, Hyperplasia              |                                  1                                       |             
      Epiglottis, Metaplasia, Squamous     |                                                          1               |             
      Glands, Inflammation, Suppurative    |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar Epithelium, Hyperplasia     |          3              2                                                |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                1         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Olfactory Epithelium, Degeneration   |       1                          1        1     1        1               |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                             +            |             
                                            __________________________________________________________________________|             
   Eye                                     |                                     +                                    |             
      Cornea, Inflammation, Chronic Active |                                     1                                    |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                     +                                    |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                   3                                                      |             
      Infarct                              |                                     3                                    |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 1  2     2  2  2  2  2  2     1        4  2  2  2  2  2  2  2  2  1     1|             
      Pelvis, Dilatation                   | 3                                                                        |             
      Pelvis, Inflammation, Acute          |                                                 2                        |             
      Transitional Epithelium, Hyperplasia |          1                                                               |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                 1                        |             
      Artery, Inflammation                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 4| 7| 4| 7| 5| 7| 7| 5| 3| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 1| 3| 4| 3| 6| 3| 3| 3| 2| 3| 1| 3| 7| 3| 3| 3| 3| 2| 3|            |
                                           | 3| 4| 3| 3| 3| 3| 0| 3| 8| 4| 0| 3| 4| 5| 2| 3| 1| 3| 2| 3| 4| 3| 3| 8| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|      A     |
    1000 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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  M  A  +  M  +  +  A  +  +  +  +  +  +|  42        |
      Hyperplasia                          |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Parasite Metazoan                    |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |          X                                               X              X|      3     |
      Clear Cell Focus                     |                                                                          |      3     |
      Degeneration, Fatty                  |    1                                                                     |      1  1.0|
      Eosinophilic Focus                   | X     X                                                                 X|      3     |
      Infarct, Focal                       |                            4                                             |      2  4.0|
      Necrosis                             |                         3                                                |      1  3.0|
      Tension Lipidosis                    |                                           X                              |      1     |
      Centrilobular, Necrosis              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                +         |   5        |
      Fat, Necrosis                        |                                                                          |      4  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                                                                          |      1  1.0|
      Lipomatosis                          |                            2                                   4         |      2  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                           3                              |      2  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Chronic Active         |                                              1                           |      2  1.0|
      Artery, Inflammation                 |                                                                3         |      1  3.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   2        |
      Developmental Malformation           |                                                                          |      1     |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1        1  1              1        1           1  1           1         |     26  1.1|
      Mineralization                       |                                           2                              |      1  2.0|
      Atrium, Thrombosis                   |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE 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  42                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 4| 7| 4| 7| 5| 7| 7| 5| 3| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 1| 3| 4| 3| 6| 3| 3| 3| 2| 3| 1| 3| 7| 3| 3| 3| 3| 2| 3|            |
                                           | 3| 4| 3| 3| 3| 3| 0| 3| 8| 4| 0| 3| 4| 5| 2| 3| 1| 3| 2| 3| 4| 3| 3| 8| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|      A     |
    1000 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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2        2                          2        2     2  1     2  1     2  2|     18  1.9|
      Hypertrophy                          | 1  2  2  2  2              2  1  1              2        1     1        1|     26  1.6|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                                                                          |      1  2.0|
      Pars Intermedia, Hyperplasia         |                                                 2                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |             1                    1  2                          1  2     1|     14  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                               2                                          |      6  2.5|
      Inflammation, Chronic Active         | 4                                                                        |      3  3.3|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Hyperplasia                          |                                                    2                     |      1  2.0|
      Inflammation, Chronic Active         |                                                 2                        |      2  1.5|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                           2                              |      1  2.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  M  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  M  +  M|  33        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  M  +  +  +  +  +  +  +  M  +  M  +  +  +  +  M  +  +  +  +  M|  36        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  M  +  M  M  +  +  M  M  M  M  +  M  +  +  M  +  +  +  M  +  +  +|  28        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                       2                  |      1  2.0|
      Hematopoietic Cell Proliferation     |                   2     4                       3                       2|      8  2.6|
 __________________________________________________________________________________________________________________________________ 
  * : 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  43                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 4| 7| 4| 7| 5| 7| 7| 5| 3| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 1| 3| 4| 3| 6| 3| 3| 3| 2| 3| 1| 3| 7| 3| 3| 3| 3| 2| 3|            |
                                           | 3| 4| 3| 3| 3| 3| 0| 3| 8| 4| 0| 3| 4| 5| 2| 3| 1| 3| 2| 3| 4| 3| 3| 8| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|      A     |
    1000 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               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Thymus                                  | M  +  M  +  M  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|  42        |
      Artery, Inflammation                 |                                                                3         |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      2  3.0|
      Prepuce, Inflammation, Acute         |                                                 1                       4|      4  2.8|
      Subcutaneous Tissue, Edema           |                                                                      3   |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                      +   |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                               +                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epiglottis, Hyperplasia              |                                                                          |      1  1.0|
      Epiglottis, Metaplasia, Squamous     |                                                                          |      1  1.0|
      Glands, Inflammation, Suppurative    |                                                             1            |      1  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar Epithelium, Hyperplasia     |                                                                2         |      3  2.3|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                         2|      1  2.0|
      Olfactory Epithelium, Degeneration   |    1  1           1                       2                          1  1|     11  1.1|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
      Cornea, Inflammation, Chronic Active |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |       +                                         +                        |   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  44                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 4| 7| 4| 7| 5| 7| 7| 5| 3| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 1| 3| 4| 3| 6| 3| 3| 3| 2| 3| 1| 3| 7| 3| 3| 3| 3| 2| 3|            |
                                           | 3| 4| 3| 3| 3| 3| 0| 3| 8| 4| 0| 3| 4| 5| 2| 3| 1| 3| 2| 3| 4| 3| 3| 8| 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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|      A     |
    1000 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|            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  3.0|
      Infarct                              |                                                                          |      1  3.0|
      Mineralization                       |                                                 2                        |      1  2.0|
      Nephropathy                          | 2  1  2  2  2  2  1  1  1  1  1  1  1     2  2  2  2  1  1  1  1  2  1  3|     44  1.7|
      Pelvis, Dilatation                   |                                                                          |      1  3.0|
      Pelvis, Inflammation, Acute          |                                                 3                        |      2  2.5|
      Transitional Epithelium, Hyperplasia |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|  48        |
      Inflammation, Chronic Active         |                                                 2                        |      2  1.5|
      Artery, Inflammation                 |                                                                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  45                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 6| 5| 7| 7| 7| 6| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 8| 3| 2| 3| 5| 9| 3| 3| 3| 3| 4| 1| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3|             
                                           | 3| 3| 8| 3| 3| 3| 8| 7| 4| 4| 4| 9| 9| 5| 5| 3| 4| 3| 3| 3| 0| 5| 3| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                           X     X                        |             
      Clear Cell Focus                     |                               X              X                           |             
      Cyst                                 |                                                                          |             
      Eosinophilic Focus                   |                                              X           X               |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                   +                                +                     |             
      Fat, Necrosis                        |                   2                                                      |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                         4                                                |             
      Inflammation, Chronic Active         |                                                                          |             
      Lipomatosis                          |                         4        4           2                           |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                         2|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                    2                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |          1  1     1  1  1     1  1        1  1     2     2  1            |             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2        2  1                             2  1  2  2           2         |             
      Hypertrophy                          |       2        1  2     2  2  1     2        2           2     2  1  2   |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  I  +  +  +  +  +  +  M  +  M  +  +  +  M  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Pars Intermedia, Hyperplasia         |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicular Cell, Hyperplasia         |    3                       2                 1           2        1  3   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  46                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 6| 5| 7| 7| 7| 6| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 8| 3| 2| 3| 5| 9| 3| 3| 3| 3| 4| 1| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3|             
                                           | 3| 3| 8| 3| 3| 3| 8| 7| 4| 4| 4| 9| 9| 5| 5| 3| 4| 3| 3| 3| 0| 5| 3| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    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|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Penis                                   | +                                   +                                    |             
      Inflammation, Chronic Active         |                                     3                                    |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                     2              2                 3   |             
      Inflammation, Chronic Active         |                               3                          3  3            |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                             +  +         |             
      Iliac, Infiltration Cellular, Plasma |                                                                          |             
          Cell                             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  M  +  +  +  +  +  +  M  +  M  +  +  +  M  +  +  M  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  M  +  +  +  +  M  +  M  +  +  +  +  M  M  +  M  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |       3                                                                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  M  +  +  +  +  +  M  M  +  M  +  +  M  M  +  M  +  M  +  +  M  +  M  M|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |             4        4           4                                       |             
      Hyperplasia, Lymphoid                |                                                                   2      |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  M  M  M  M  +  M  +  +  +  +  M  M  +  +  M  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Prepuce, Inflammation, Acute         |                      4                                                   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst Epithelial Inclusion            |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epiglottis, Metaplasia, Squamous     |                                        1                                 |             
      Glands, Inflammation, Suppurative    |                               1                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  47                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 7| 7| 7| 6| 5| 7| 7| 7| 6| 6| 4| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 8| 3| 2| 3| 5| 9| 3| 3| 3| 3| 4| 1| 3| 3| 3| 2| 3| 3| 7| 3| 3| 3| 3|             
                                           | 3| 3| 8| 3| 3| 3| 8| 7| 4| 4| 4| 9| 9| 5| 5| 3| 4| 3| 3| 3| 0| 5| 3| 3| 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|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Inflammation, Suppurative            |                                                    1                     |             
      Olfactory Epithelium, Degeneration   | 2  2  2  2  2  2  1  2  1  2  1  1  2  1  1  1  1  2  1  1  1  1  1  1   |             
      Olfactory Epithelium, Necrosis       |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                +                                                         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Infarct                              |                            2                       2                     |             
      Mineralization                       |                                        2                                 |             
      Necrosis                             |                                        2                                 |             
      Nephropathy                          | 1  2     2     2  1  1  1  1  2  2  1  1  2  2  2     2  2  1  2  2  2  2|             
      Artery, Inflammation                 |                                                                          |             
      Pelvis, Inflammation, Acute          |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Acute                  |                      2                                                   |             
      Inflammation, Chronic Active         |                                                                          |             
      Transitional Epithelium, Hyperplasia |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  48                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 6| 5| 7| 7| 7| 7| 7| 6| 7| 6| 4| 7| 7| 6| 5| 7| 7|            |
                             DAY ON TEST   | 7| 3| 3| 5| 3| 3| 6| 3| 9| 7| 3| 3| 3| 3| 3| 5| 3| 9| 9| 3| 3| 1| 4| 0| 3|            |
                                           | 9| 4| 5| 3| 5| 4| 5| 4| 0| 1| 3| 4| 5| 3| 3| 3| 3| 1| 9| 3| 5| 6| 7| 9| 3|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|      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        |
                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  M  M  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     | X                                   X                                    |      4     |
      Clear Cell Focus                     |                                                                          |      2     |
      Cyst                                 |                                                 3                        |      1  3.0|
      Eosinophilic Focus                   |                               X                                          |      3     |
      Mixed Cell Focus                     |                      X                                                   |      1     |
      Necrosis                             |                   2     2                                                |      2  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                   +      |   3        |
      Fat, Necrosis                        |                                                                   2      |      2  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  4.0|
      Inflammation, Chronic Active         | 2                                                                        |      1  2.0|
      Lipomatosis                          |                               1                       2                  |      5  2.6|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 1  1        1  1              1     1  2  2  2     2     1  2  2  1  2   |     27  1.3|
      Inflammation, Suppurative            |                            3                                             |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |       3     2                 2        2  2  1  2  2        2  1         |     18  1.8|
      Hypertrophy                          |    2     1  2  1     1        2  1        2     2        2  2     1  1  1|     26  1.6|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  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  49                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 6| 5| 7| 7| 7| 7| 7| 6| 7| 6| 4| 7| 7| 6| 5| 7| 7|            |
                             DAY ON TEST   | 7| 3| 3| 5| 3| 3| 6| 3| 9| 7| 3| 3| 3| 3| 3| 5| 3| 9| 9| 3| 3| 1| 4| 0| 3|            |
                                           | 9| 4| 5| 3| 5| 4| 5| 4| 0| 1| 3| 4| 5| 3| 3| 3| 3| 1| 9| 3| 5| 6| 7| 9| 3|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|      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|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Intermedia, Hyperplasia         | 2                                                                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicular Cell, Hyperplasia         |                   1  1  1                          2                 3  1|     12  1.8|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   2        |
      Inflammation, Chronic Active         |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |       3                                                                  |      4  2.5|
      Inflammation, Chronic Active         |                      2                 2                                 |      5  2.6|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                         +                                      +         |   4        |
      Iliac, Infiltration Cellular, Plasma |                                                                          |            |
          Cell                             |                                                                3         |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  +  +  M  +  M  M  +  +  +  M  M  +  +  M  +  M  M  M  +  +  +  M  +  +|  34        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  M  +  +  M  +  M  M  M  M  +  M  +  M  +  +  +  +  M  +  M  +  +  M  M|  31        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  47        |
      Angiectasis                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  M  +  M|  34        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                            4           2     2     3              3  3   |      9  3.2|
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | M  +  +  +  M  +  +  +  +  M  +  +  M  M  +  +  +  M  +  +  +  +  +  +  +|  36        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Prepuce, Inflammation, Acute         |                            3        4        4  4  4           4  4  4   |      9  3.9|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL 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  50                                                               
NTP Experiment-Test: 60968-02                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 09/23/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 16:11:49  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 6| 5| 7| 7| 7| 7| 7| 6| 7| 6| 4| 7| 7| 6| 5| 7| 7|            |
                             DAY ON TEST   | 7| 3| 3| 5| 3| 3| 6| 3| 9| 7| 3| 3| 3| 3| 3| 5| 3| 9| 9| 3| 3| 1| 4| 0| 3|            |
                                           | 9| 4| 5| 3| 5| 4| 5| 4| 0| 1| 3| 4| 5| 3| 3| 3| 3| 1| 9| 3| 5| 6| 7| 9| 3|      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     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|      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|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst Epithelial Inclusion            |                                                                          |      1     |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epiglottis, Metaplasia, Squamous     |                                                       1        1         |      3  1.0|
      Glands, Inflammation, Suppurative    |                                        2  1                              |      3  1.3|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar Epithelium, Hyperplasia     |                                  1                             1         |      2  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            | 2                                                     1                  |      3  1.3|
      Olfactory Epithelium, Degeneration   |    1        2  1  2  1  2  1  1  1  1  2  1  1  1  2  2  1  2  1  2  2   |     45  1.4|
      Olfactory Epithelium, Necrosis       | 2                                                                        |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                  +                                       |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |       2                                                                  |      1  2.0|
      Infarct                              |                2     2                                               2   |      5  2.0|
      Mineralization                       |                                                                          |      1  2.0|
      Necrosis                             |                                                                          |      1  2.0|
      Nephropathy                          | 2  2  2  4  2  2  2  2  1     2  2  2  2  2  1  2  1  2  2  2  2  1     2|     45  1.8|
      Artery, Inflammation                 |                                     2        2                           |      2  2.0|
      Pelvis, Inflammation, Acute          |                            4                                         2   |      2  3.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Acute                  |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |                            2                                      4  4   |      3  3.3|
      Transitional Epithelium, Hyperplasia |             2                                                            |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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  51                                                               
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