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TDMS Study 60968-01 Pathology Tables

NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  0078-84-2

       Lock Date:  06/01/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































                                                              Page   1

NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 5| 7| 4| 6| 7| 6| 4| 6| 7| 7| 7| 4| 7| 5| 6| 7| 4|             
                             DAY ON TEST   | 3| 1| 3| 3| 3| 3| 3| 3| 4| 2| 9| 9| 3| 2| 0| 7| 3| 3| 3| 4| 3| 8| 9| 3| 4|             
                                           | 5| 7| 5| 5| 5| 4| 4| 5| 7| 0| 6| 0| 4| 3| 0| 9| 5| 5| 5| 7| 5| 0| 5| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Periesophageal Tissue, Inflammation, |                                                                          |             
           Chronic Active                  |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         |    X                                                                     |             
      Parasite Metazoan                    |                            X                    X                        |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    | X           X                                      X                     |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |          X     X                    X                 X                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Basophilic Focus                     | X                                                                        |             
      Basophilic Focus, Multiple           |       X     X                                                            |             
      Clear Cell Focus                     |                                           X                 X            |             
      Clear Cell Focus, Multiple           |                            X                                             |             
      Hepatodiaphragmatic Nodule           |                            X  X                                   X      |             
      Inflammation, Granulomatous          |             2                                                        2   |             
      Vacuolization Cytoplasmic            |                      4        3                          4               |             
      Hepatocyte, Hyperplasia              |                                                                          |             
      Serosa, Hemorrhage                   |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                         +                             +                  |             
      Fat, Necrosis                        |                         3                             3                  |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |             +                                               +            |             
      Fibrosis                             |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
      Pharyngeal, Hyperplasia              |             3                                               3            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                     2                 2                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia                          |                      3                                            3     3|             
      Inflammation, Suppurative            |                      2                                                   |             
      Ulcer                                |                                                                   4      |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                +                                                         |             
      Epithelium, Hyperplasia              |                4                                                         |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Developmental Malformation           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 5| 7| 4| 6| 7| 6| 4| 6| 7| 7| 7| 4| 7| 5| 6| 7| 4|             
                             DAY ON TEST   | 3| 1| 3| 3| 3| 3| 3| 3| 4| 2| 9| 9| 3| 2| 0| 7| 3| 3| 3| 4| 3| 8| 9| 3| 4|             
                                           | 5| 7| 5| 5| 5| 4| 4| 5| 7| 0| 6| 0| 4| 3| 0| 9| 5| 5| 5| 7| 5| 0| 5| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                                                          |             
      Atrium, Thrombosis                   |                               2                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
      Vacuolization Cytoplasmic            |       2           1  3  2        1           2        1     3     3      |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                               1  3                             2         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                3        3                                   2  3         |             
      Pars Distalis, Hyperplasia           |       2     2                                         1     2     2      |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |             2              1                    2           2            |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Peritoneum                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                      4        3  4                                       |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Suppurative            |                      4                                                   |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Endometrium, Hyperplasia             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                               +                          +               |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 5| 7| 4| 6| 7| 6| 4| 6| 7| 7| 7| 4| 7| 5| 6| 7| 4|             
                             DAY ON TEST   | 3| 1| 3| 3| 3| 3| 3| 3| 4| 2| 9| 9| 3| 2| 0| 7| 3| 3| 3| 4| 3| 8| 9| 3| 4|             
                                           | 5| 7| 5| 5| 5| 4| 4| 5| 7| 0| 6| 0| 4| 3| 0| 9| 5| 5| 5| 7| 5| 0| 5| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                X     X                                   X           X   |             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                3         |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Granulomatous          |                                                                          |             
      Ulcer                                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                              3           2               |             
      Ventricle, Hydrocephalus             |                            3           3  2                              |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                                                                X        X|             
      Epiglottis, Metaplasia, Squamous     |                                                       1                  |             
      Epithelium, Hyperplasia              |                                              2           2  3            |             
      Epithelium, Metaplasia, Squamous     |                                                       1        2         |             
      Glands, Inflammation, Suppurative    |          3                                                  4            |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           | 2                 1                                                     3|             
      Inflammation, Granulomatous          |                                                             1            |             
      Alveolar Epithelium, Fibrosis        |          2                                                  2            |             
      Alveolar Epithelium, Foreign Body    |    X                                                                     |             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             |       2  1                                                  1            |             
      Bronchiole, Hyperplasia              |                                                                      3   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 7| 7| 7| 7| 7| 5| 7| 4| 6| 7| 6| 4| 6| 7| 7| 7| 4| 7| 5| 6| 7| 4|             
                             DAY ON TEST   | 3| 1| 3| 3| 3| 3| 3| 3| 4| 2| 9| 9| 3| 2| 0| 7| 3| 3| 3| 4| 3| 8| 9| 3| 4|             
                                           | 5| 7| 5| 5| 5| 4| 4| 5| 7| 0| 6| 0| 4| 3| 0| 9| 5| 5| 5| 7| 5| 0| 5| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Foreign Body                         |                                                                          |             
      Inflammation, Suppurative            |                               1                 2                        |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                               3                                          |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         |                                                 3                        |             
      Respiratory Epithelium, Hyperplasia  |                                                                          |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pleura                                  |                                                                          |             
      Inflammation                         |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                            +                                      +      |             
      Lens, Cataract                       |                                                                   3      |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 2  1     1     1  3  1     2  2     1        2  1  1  1     2     2  1  1|             
      Medulla, Renal Tubule, Cyst          |                                                                          |             
      Renal Tubule, Mineralization         | 1           1  1                                         2        1      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Transitional Epithelium, Hyperplasia |                               2                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   5                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 7| 7| 0| 6| 5| 6| 7| 5| 7| 7| 6| 7|            |
                             DAY ON TEST   | 2| 3| 8| 3| 3| 3| 3| 3| 3| 7| 3| 4| 3| 3| 3| 5| 9| 8| 2| 3| 6| 3| 2| 1| 3|            |
                                           | 8| 4| 7| 4| 4| 4| 5| 4| 5| 8| 5| 7| 5| 4| 4| 6| 2| 0| 5| 4| 1| 4| 5| 6| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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                               | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Periesophageal Tissue, Inflammation, |                                                                          |            |
           Chronic Active                  |                                     2                                    |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Diverticulum                         |                                                                          |      1     |
      Parasite Metazoan                    |                                                 X                        |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Parasite Metazoan                    |                X                       X  X                              |      6     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Parasite Metazoan                    |                                                                          |      4     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          |                                                                         2|      1  2.0|
      Basophilic Focus                     |                   X                                                      |      2     |
      Basophilic Focus, Multiple           |                                        X                                 |      3     |
      Clear Cell Focus                     |                                                 X     X                  |      4     |
      Clear Cell Focus, Multiple           |                X  X        X           X                                 |      5     |
      Hepatodiaphragmatic Nodule           |    X                    X     X                                          |      6     |
      Inflammation, Granulomatous          |                                                                          |      2  2.0|
      Vacuolization Cytoplasmic            |                                                    4  3                  |      5  3.6|
      Hepatocyte, Hyperplasia              |                                                                   3      |      1  3.0|
      Serosa, Hemorrhage                   |                                                                2         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |       +                          +              +                    +  +|   7        |
      Fat, Necrosis                        |                                                 4                    3  3|      5  3.2|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                              +           +               |   4        |
      Fibrosis                             |                                              4                           |      1  4.0|
      Hyperplasia                          |                                                          2               |      1  2.0|
      Inflammation, Chronic                |                                              3                           |      1  3.0|
      Pharyngeal, Hyperplasia              |                                                                          |      2  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                               1                                          |      3  1.7|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperkeratosis                       |                                                    3                     |      1  3.0|
      Hyperplasia                          |                                                    3                 2   |      5  2.8|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Ulcer                                |                                                                          |      1  4.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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   6                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 7| 7| 0| 6| 5| 6| 7| 5| 7| 7| 6| 7|            |
                             DAY ON TEST   | 2| 3| 8| 3| 3| 3| 3| 3| 3| 7| 3| 4| 3| 3| 3| 5| 9| 8| 2| 3| 6| 3| 2| 1| 3|            |
                                           | 8| 4| 7| 4| 4| 4| 5| 4| 5| 8| 5| 7| 5| 4| 4| 6| 2| 0| 5| 4| 1| 4| 5| 6| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
      Epithelium, Hyperplasia              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                              +                           |   1        |
      Developmental Malformation           |                                              X                           |      1     |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |             2                                                            |      1  2.0|
      Atrium, Thrombosis                   | 3                                                                        |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                   1                                                      |      1  1.0|
      Vacuolization Cytoplasmic            |                                           4        3  2                  |     12  2.3|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                2                                                         |      4  2.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                        3                                 |      1  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|  48        |
      Cyst                                 |                                                 3  3                     |      6  2.8|
      Pars Distalis, Hyperplasia           |          2                    3                             4  3         |      9  2.3|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Hyperplasia                  |                         1              1                          1     1|      8  1.4|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Peritoneum                              |                                                          +               |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Cyst                                 |             4                    3  3                                   3|      7  3.4|
      Hyperplasia                          |             4                                                           3|      2  3.5|
      Inflammation, Suppurative            |                                                                   3      |      2  3.5|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Uterus                                  | A  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Endometrium, Hyperplasia             |          4                                                               |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page   7                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 7| 7| 0| 6| 5| 6| 7| 5| 7| 7| 6| 7|            |
                             DAY ON TEST   | 2| 3| 8| 3| 3| 3| 3| 3| 3| 7| 3| 4| 3| 3| 3| 5| 9| 8| 2| 3| 6| 3| 2| 1| 3|            |
                                           | 8| 4| 7| 4| 4| 4| 5| 4| 5| 8| 5| 7| 5| 4| 4| 6| 2| 0| 5| 4| 1| 4| 5| 6| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    CONTROL                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                  +                                   +   |   4        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  A  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  45        |
      Hyperplasia, Lymphoid                |                                              4                           |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          |          4                                                               |      1  4.0|
      Hemorrhage                           |                                                                2         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia, Lymphoid                |                                              3                           |      1  3.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Accessory Spleen                     |                                                                          |      4     |
      Fibrosis                             |                            3                          3                  |      2  3.0|
      Hematopoietic Cell Proliferation     |                                                                          |      1  3.0|
      Hemorrhage                           |                                                                      4   |      1  4.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                                          2               |      1  2.0|
      Inflammation, Chronic                |    3                                                                     |      1  3.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperkeratosis                       |                         4                                                |      1  4.0|
      Hyperplasia                          |                         4                                                |      1  4.0|
      Inflammation, Granulomatous          |    3                                                                     |      1  3.0|
      Ulcer                                |             3                                                            |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           | 4                                                                    2   |      4  2.8|
      Ventricle, Hydrocephalus             |                            3                                      2      |      5  2.6|
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                          +               |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  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   8                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 4| 7| 6| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 7| 7| 0| 6| 5| 6| 7| 5| 7| 7| 6| 7|            |
                             DAY ON TEST   | 2| 3| 8| 3| 3| 3| 3| 3| 3| 7| 3| 4| 3| 3| 3| 5| 9| 8| 2| 3| 6| 3| 2| 1| 3|            |
                                           | 8| 4| 7| 4| 4| 4| 5| 4| 5| 8| 5| 7| 5| 4| 4| 6| 2| 0| 5| 4| 1| 4| 5| 6| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Foreign Body                         |    X           X                       X                                X|      6     |
      Epiglottis, Metaplasia, Squamous     |                2                                                         |      2  1.5|
      Epithelium, Hyperplasia              |                                     2  2                                 |      5  2.2|
      Epithelium, Metaplasia, Squamous     |                2                    2                                   3|      5  2.0|
      Glands, Inflammation, Suppurative    |                                     2     2                             4|      5  3.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      3  2.0|
      Inflammation, Granulomatous          |                                                                          |      1  1.0|
      Alveolar Epithelium, Fibrosis        |                                                       3                 3|      4  2.5|
      Alveolar Epithelium, Foreign Body    |                                                                          |      1     |
      Alveolar Epithelium, Hyperplasia     |                                     2                                    |      1  2.0|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |                1              1  3  2     2           4                 1|     10  1.8|
      Bronchiole, Hyperplasia              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Foreign Body                         |                                        X        X                        |      2     |
      Inflammation, Suppurative            |                                                                          |      2  1.5|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                                                                          |      1  3.0|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         |                                                                          |      1  3.0|
      Respiratory Epithelium, Hyperplasia  |                                                                         1|      1  1.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pleura                                  |                                                                         +|   1        |
      Inflammation                         |                                                                         3|      1  3.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                        +                                 |   3        |
      Lens, Cataract                       |                                        3                                 |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Nephropathy, Chronic                 |    3     1  2  3  1  1  2  3     1  1  2  2        1  1  1     1  4     2|     35  1.6|
      Medulla, Renal Tubule, Cyst          |          3                                                               |      1  3.0|
      Renal Tubule, Mineralization         |                                                                          |      5  1.2|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Transitional Epithelium, Hyperplasia |                                  3                                       |      2  2.5|
 __________________________________________________________________________________________________________________________________ 
  * : 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   9                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 7| 5| 5| 7| 6| 7| 6| 6| 6| 7| 7| 7| 7| 7| 6| 7| 6| 5| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 9| 3| 1| 2| 3| 6| 0| 9| 3| 8| 3| 3| 3| 0| 3| 7| 3| 4| 5| 3| 8| 0|             
                                           | 5| 4| 5| 1| 4| 1| 4| 4| 3| 5| 2| 6| 1| 5| 4| 5| 1| 4| 8| 4| 0| 2| 4| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    500 PPM                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
      Parasite Metazoan                    |                                                    X                     |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +|             
      Parasite Metazoan                    |                         X                                                |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |          2                                                               |             
      Clear Cell Focus                     |                                  X                                       |             
      Clear Cell Focus, Multiple           |                                                       X                  |             
      Eosinophilic Focus                   |                                                                          |             
      Hepatodiaphragmatic Nodule           |                         X                                X     X         |             
      Vacuolization Cytoplasmic            |                                                 4                        |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +                                                  +            |             
      Artery, Inflammation, Chronic        |                                                                          |             
      Fat, Necrosis                        |                                                             2            |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                   3     3|             
      Artery, Inflammation, Chronic        |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                3                                                        2|             
      Ulcer                                |                4                                                         |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vacuolization Cytoplasmic            |                         2                       1                        |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                 4        2               |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                        2                                 |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  M  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  10                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 7| 5| 5| 7| 6| 7| 6| 6| 6| 7| 7| 7| 7| 7| 6| 7| 6| 5| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 9| 3| 1| 2| 3| 6| 0| 9| 3| 8| 3| 3| 3| 0| 3| 7| 3| 4| 5| 3| 8| 0|             
                                           | 5| 4| 5| 1| 4| 1| 4| 4| 3| 5| 2| 6| 1| 5| 4| 5| 1| 4| 8| 4| 0| 2| 4| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                   |                                                                          |             
                                           |                                                                          |             
      Cyst                                 | 4     3           2  3              2  1           3        4  4         |             
      Hemorrhage                           |          4                                                              3|             
      Pars Distalis, Hyperplasia           |    3                                   2        3                        |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |                         1                             1                  |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                4           4     3              4                        |             
      Hyperplasia                          |                            4                    3                        |             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                         2|             
      Endometrium, Hyperplasia             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                +                                                     +   |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                                                                          |             
      Angiectasis                          |                                                                          |             
      Fibrosis                             | 3                                               2                        |             
      Hematopoietic Cell Proliferation     |                4                                                         |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                   2                                                      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                        3                                 |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                 3        2        3      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  11                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 7| 5| 5| 7| 6| 7| 6| 6| 6| 7| 7| 7| 7| 7| 6| 7| 6| 5| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 9| 3| 1| 2| 3| 6| 0| 9| 3| 8| 3| 3| 3| 0| 3| 7| 3| 4| 5| 3| 8| 0|             
                                           | 5| 4| 5| 1| 4| 1| 4| 4| 3| 5| 2| 6| 1| 5| 4| 5| 1| 4| 8| 4| 0| 2| 4| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Inflammation, Suppurative            |                                                                2         |             
      Ulcer                                |                                     3                                    |             
      Epidermis, Cyst                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cranium, Fracture                    |                                                                          |             
      Cranium, Femur, Osteopetrosis        |                                                          4               |             
      Maxilla, Fracture                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Gliosis                              |                                                                          |             
      Hemorrhage                           |                                                       2                  |             
      Necrosis                             |                                                                          |             
      Ventricle, Hydrocephalus             | 3                                                     3                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
      Epithelium, Metaplasia, Squamous     |                                                                          |             
      Glands, Inflammation, Suppurative    | 1  1        1                       1     1                 2        1   |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar Epithelium, Fibrosis        |                                                                      2   |             
      Alveolar Epithelium, Hyperplasia     |          2  1                                                     4      |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             | 1        2  1              1                                         3  2|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 1                                                                        |             
      Foreign Body                         |                                                             X           X|             
      Hemorrhage                           |                                                                          |             
      Inflammation, Suppurative            |                            2                                             |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                            2                    1        1               |             
                                            __________________________________________________________________________|             
   Pleura                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                             +            |             
      Cornea, Mineralization               |                                                                          |             
      Lens, Cataract                       |                                                             3            |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  12                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 7| 5| 5| 7| 6| 7| 6| 6| 6| 7| 7| 7| 7| 7| 6| 7| 6| 5| 7| 6| 7|             
                             DAY ON TEST   | 3| 3| 3| 9| 3| 1| 2| 3| 6| 0| 9| 3| 8| 3| 3| 3| 0| 3| 7| 3| 4| 5| 3| 8| 0|             
                                           | 5| 4| 5| 1| 4| 1| 4| 4| 3| 5| 2| 6| 1| 5| 4| 5| 1| 4| 8| 4| 0| 2| 4| 7| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 3  1                          1        1     1     1  3  2     1  2     1|             
      Renal Tubule, Mineralization         |                                                       2                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  13                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 7| 7| 7| 5| 6| 6| 6| 5| 7| 7| 6| 7| 5|            |
                             DAY ON TEST   | 4| 9| 3| 3| 3| 3| 7| 3| 1| 3| 3| 3| 3| 3| 3| 7| 7| 2| 3| 5| 3| 0| 0| 3| 4|            |
                                           | 2| 5| 4| 5| 4| 4| 1| 4| 2| 4| 5| 5| 5| 4| 5| 5| 8| 4| 6| 1| 4| 6| 8| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    500 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |    X                                                                    X|      2     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                                     X                                    |      2     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Clear Cell Focus                     |       X     X           X                                               X|      5     |
      Clear Cell Focus, Multiple           |                                                                          |      1     |
      Eosinophilic Focus                   |                                     X                                    |      1     |
      Hepatodiaphragmatic Nodule           |          X     X                                            X            |      6     |
      Vacuolization Cytoplasmic            | 4                                                                        |      2  4.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +     +           +        +     +|   7        |
      Artery, Inflammation, Chronic        |                                                          4               |      1  4.0|
      Fat, Necrosis                        |                                        3     3                    4      |      4  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                                          |      2  3.0|
      Artery, Inflammation, Chronic        |                                                          3               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                                                                          |      2  2.5|
      Ulcer                                |                                                                   4      |      2  4.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |       +                                                                  |   1        |
      Inflammation, Suppurative            |       3                                                                  |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Vacuolization Cytoplasmic            |                         2  2                                         2   |      5  1.8|
                                            __________________________________________________________________________|____________|
   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  14                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 7| 7| 7| 5| 6| 6| 6| 5| 7| 7| 6| 7| 5|            |
                             DAY ON TEST   | 4| 9| 3| 3| 3| 3| 7| 3| 1| 3| 3| 3| 3| 3| 3| 7| 7| 2| 3| 5| 3| 0| 0| 3| 4|            |
                                           | 2| 5| 4| 5| 4| 4| 1| 4| 2| 4| 5| 5| 5| 4| 5| 5| 8| 4| 6| 1| 4| 6| 8| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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  3.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                2           3              1                       4     1|     14  2.6|
      Hemorrhage                           |                                                                          |      2  3.5|
      Pars Distalis, Hyperplasia           |    2           2                                                  3      |      6  2.5|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Hyperplasia                  | 2              2                    2        2                       1   |      7  1.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                             +            |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 | 3  3  3              2           4        3                       3      |     11  3.3|
      Hyperplasia                          |                                  3        2                              |      4  3.0|
      Inflammation, Suppurative            | 3                                                                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |       3                                                                  |      1  3.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  2.0|
      Endometrium, Hyperplasia             |                      3                                                   |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                    +                 +   |   4        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                      4   |      1  4.0|
      Hemorrhage                           |                   2                                                      |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Fibrosis                             |                                     3                                    |      1  3.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Accessory Spleen                     |                                                    X                     |      1     |
      Angiectasis                          |                                                             4            |      1  4.0|
      Fibrosis                             |                                                                          |      2  2.5|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  15                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 7| 7| 7| 5| 6| 6| 6| 5| 7| 7| 6| 7| 5|            |
                             DAY ON TEST   | 4| 9| 3| 3| 3| 3| 7| 3| 1| 3| 3| 3| 3| 3| 3| 7| 7| 2| 3| 5| 3| 0| 0| 3| 4|            |
                                           | 2| 5| 4| 5| 4| 4| 1| 4| 2| 4| 5| 5| 5| 4| 5| 5| 8| 4| 6| 1| 4| 6| 8| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    500 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hematopoietic Cell Proliferation     |                                                                          |      1  4.0|
      Hemorrhage                           |                         3                          4                     |      2  3.5|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                                        4                                 |      4  3.0|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Ulcer                                |                      3                 4                                 |      3  3.3|
      Epidermis, Cyst                      |             3                                   4                        |      2  3.5|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cranium, Fracture                    |             4                                                            |      1  4.0|
      Cranium, Femur, Osteopetrosis        |                                                                          |      1  4.0|
      Maxilla, Fracture                    |                   X                                                      |      1     |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Gliosis                              |             3                                                            |      1  3.0|
      Hemorrhage                           |                         3                                                |      2  2.5|
      Necrosis                             |             4                                                            |      1  4.0|
      Ventricle, Hydrocephalus             |                                              4                           |      3  3.3|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |             X                                         X                  |      2     |
      Inflammation, Suppurative            |             4                                                            |      1  4.0|
      Epithelium, Hyperplasia              |                                                       3                  |      1  3.0|
      Epithelium, Metaplasia, Squamous     |                                                       2                  |      1  2.0|
      Glands, Inflammation, Suppurative    |                            1                 1     1                 1   |     11  1.1|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar Epithelium, Fibrosis        |                                                                         1|      2  1.5|
      Alveolar Epithelium, Hyperplasia     |                2                    2                                1   |      6  2.0|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |                2                    2                                1  1|     10  1.6|
 __________________________________________________________________________________________________________________________________ 
  * : 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  16                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 7| 7| 7| 0| 7| 7| 7| 7| 7| 7| 7| 7| 5| 6| 6| 6| 5| 7| 7| 6| 7| 5|            |
                             DAY ON TEST   | 4| 9| 3| 3| 3| 3| 7| 3| 1| 3| 3| 3| 3| 3| 3| 7| 7| 2| 3| 5| 3| 0| 0| 3| 4|            |
                                           | 2| 5| 4| 5| 4| 4| 1| 4| 2| 4| 5| 5| 5| 4| 5| 5| 8| 4| 6| 1| 4| 6| 8| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    500 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                            1                                             |      2  1.0|
      Foreign Body                         |                                                                          |      2     |
      Hemorrhage                           |                   4                                                      |      1  4.0|
      Inflammation, Suppurative            |                               3                             1            |      3  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |          1     1        1     3  1                          2        1  1|     11  1.4|
                                            __________________________________________________________________________|____________|
   Pleura                                  |    +                                                                     |   1        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     | +                                                                        |   2        |
      Cornea, Mineralization               | 2                                                                        |      1  2.0|
      Lens, Cataract                       |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Nephropathy, Chronic                 | 2     2  2  2  1     3  2  2  1  2  3  1  1  1  2     1     1  1  1      |     30  1.6|
      Renal Tubule, Mineralization         |                         2                                                |      2  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  17                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 5| 4| 6| 6| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 8| 0| 0| 8| 9| 7| 8| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 8|             
                                           | 5| 5| 5| 5| 8| 8| 7| 2| 7| 9| 1| 5| 5| 4| 4| 4| 5| 6| 5| 4| 2| 5| 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| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                   X      |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                             X  X         |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         |                                     X                                    |             
      Parasite Metazoan                    |                         X                                                |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                      X                       X                           |             
      Clear Cell Focus                     |                      X        X  X                                       |             
      Clear Cell Focus, Multiple           |                                                       X                  |             
      Hepatodiaphragmatic Nodule           | X        X  X           X                                   X        X   |             
      Vacuolization Cytoplasmic            |                   3                                                      |             
                                            __________________________________________________________________________|             
   Mesentery                               |             +                                                        +   |             
      Fat, Necrosis                        |                                                                      3   |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |          +                                            +                  |             
      Inflammation, Suppurative            |          2                                                               |             
      Gingival, Inflammation, Suppurative  |                                                       4                  |             
      Pharyngeal, Hyperplasia              |          3                                                               |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |    1                                                     2               |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                   2                                   2                 3|             
      Inflammation, Suppurative            |                   2                                                      |             
      Ulcer                                |             2     2           4                                         4|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                       +     +            |             
      Developmental Malformation           |                                                             X            |             
      Inflammation, Suppurative            |                                                       4                  |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vacuolization Cytoplasmic            | 2                    2  1           3           2              2        1|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  18                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 5| 4| 6| 6| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 8| 0| 0| 8| 9| 7| 8| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 8|             
                                           | 5| 5| 5| 5| 8| 8| 7| 2| 7| 9| 1| 5| 5| 4| 4| 4| 5| 6| 5| 4| 2| 5| 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| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 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                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |       2              2           2           3                 3     4   |             
      Hemorrhage                           |                                                    2                     |             
      Pars Distalis, Hyperplasia           | 3                                                                    4   |             
      Pars Distalis, Hypertrophy           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |       1     1        1                 1  2  3           2               |             
      Follicular Cell, Hyperplasia         |       1                                                                  |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |          3                          2  2           2                     |             
      Hyperplasia                          |                                                          3               |             
      Inflammation, Suppurative            |                                                          3               |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                         2                                                |             
      Cervix, Hypertrophy                  |                                                                          |             
      Endometrium, Hyperplasia             |                         2                                                |             
      Endometrium, Metaplasia, Squamous    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                           +                    +         |             
      Renal, Pigmentation                  |                                           3                              |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Hyperplasia, Lymphoid                |                                                       2                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |       3                 3                                                |             
      Hyperplasia, Lymphoid                |                2                                                         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                                                                          |             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                      3                                                   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  19                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 5| 4| 6| 6| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 8| 0| 0| 8| 9| 7| 8| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 8|             
                                           | 5| 5| 5| 5| 8| 8| 7| 2| 7| 9| 1| 5| 5| 4| 4| 4| 5| 6| 5| 4| 2| 5| 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| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                              3                           |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Ulcer                                |                                                 3                        |             
      Epidermis, Cyst                      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                         2     4                                         4|             
      Ventricle, Hydrocephalus             |                2  3                                                      |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                   X     X     1        X  X                              |             
      Inflammation, Suppurative            |                                        1                                 |             
      Epiglottis, Metaplasia, Squamous     |                                                             1        1   |             
      Epithelium, Metaplasia, Squamous     |                   1     1     1                                          |             
      Glands, Inflammation, Suppurative    |                                           3                              |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                         2                 2                              |             
      Alveolar Epithelium, Fibrosis        |                                                                2        3|             
      Alveolar Epithelium, Hyperplasia     |                                                                3     4   |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             |                            1  3           2  1     1  1        2         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                     1     1                              |             
      Foreign Body                         |       X                                            X           X         |             
      Inflammation, Suppurative            |       4                                                     2            |             
      Olfactory Epithelium, Degeneration   |                                                                          |             
      Respiratory Epithelium, Hyperplasia  |                                                                          |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                                             2            |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
      Lens, Cataract                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  20                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 5| 4| 6| 6| 4| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 5|             
                             DAY ON TEST   | 3| 3| 3| 8| 0| 0| 8| 9| 7| 8| 0| 3| 3| 3| 3| 3| 3| 3| 3| 3| 9| 3| 3| 3| 8|             
                                           | 5| 5| 5| 5| 8| 8| 7| 2| 7| 9| 1| 5| 5| 4| 4| 4| 5| 6| 5| 4| 2| 5| 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| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    1000 PPM                               | 0| 0| 0| 0| 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|             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 1  2  1  1     1  2     1     2  1     1  2  2  2                    1   |             
      Pelvis, Dilatation                   |                      3                                                   |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                                                                          |             
      Renal Tubule, Mineralization         |       1        1  1                                      1               |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                      3                                                   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  21                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 6| 6| 7| 7| 6| 6| 6| 7| 7| 7| 7| 6| 7| 7|            |
                             DAY ON TEST   | 3| 0| 2| 5| 3| 2| 3| 3| 3| 3| 6| 8| 8| 3| 3| 8| 9| 1| 3| 3| 0| 3| 6| 0| 0|            |
                                           | 5| 6| 7| 6| 5| 0| 4| 4| 5| 5| 4| 7| 1| 4| 5| 7| 6| 4| 5| 4| 6| 5| 4| 6| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|      A     |
    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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |                                                             X  X         |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |       X                                                                  |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Diverticulum                         |                                                                          |      1     |
      Parasite Metazoan                    |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                                       X                  |      3     |
      Clear Cell Focus                     |                                                                          |      3     |
      Clear Cell Focus, Multiple           |                               X                             X            |      3     |
      Hepatodiaphragmatic Nodule           |                                                       X                  |      7     |
      Vacuolization Cytoplasmic            |                                                                      2   |      2  2.5|
                                            __________________________________________________________________________|____________|
   Mesentery                               |          +        +  +                       +        +  +               |   8        |
      Fat, Necrosis                        |                   3  3                       3        3  1               |      6  2.7|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                                          |   2        |
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Gingival, Inflammation, Suppurative  |                                                                          |      1  4.0|
      Pharyngeal, Hyperplasia              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                      1                                                   |      3  1.3|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                             3     4      |      5  2.8|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Ulcer                                |                                                             3            |      5  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                             +            |   1        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   2        |
      Developmental Malformation           |                                                                          |      1     |
      Inflammation, Suppurative            |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  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  22                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 6| 6| 7| 7| 6| 6| 6| 7| 7| 7| 7| 6| 7| 7|            |
                             DAY ON TEST   | 3| 0| 2| 5| 3| 2| 3| 3| 3| 3| 6| 8| 8| 3| 3| 8| 9| 1| 3| 3| 0| 3| 6| 0| 0|            |
                                           | 5| 6| 7| 6| 5| 0| 4| 4| 5| 5| 4| 7| 1| 4| 5| 7| 6| 4| 5| 4| 6| 5| 4| 6| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|      A     |
    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|            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vacuolization Cytoplasmic            |    2                       1                                             |      9  1.8|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 | 1              1     4  1  1                                      1     4|     13  2.2|
      Hemorrhage                           |                                                                         4|      2  3.0|
      Pars Distalis, Hyperplasia           | 3              3     4                                            3      |      6  3.3|
      Pars Distalis, Hypertrophy           |                         2                                                |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  |                                           3     2                        |      9  1.8|
      Follicular Cell, Hyperplasia         |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                          +           +   |   3        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 | 4  4  3     4  3        3  3        4                    4        3      |     14  3.1|
      Hyperplasia                          |                                                                          |      1  3.0|
      Inflammation, Suppurative            |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                      3     1                          3                  |      3  2.3|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  2.0|
      Cervix, Hypertrophy                  |    4                                                                     |      1  4.0|
      Endometrium, Hyperplasia             |                      3                                                   |      2  2.5|
      Endometrium, Metaplasia, Squamous    |                      3                                                   |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                             +     +      |   4        |
      Renal, Pigmentation                  |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                                                                          |      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  23                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 6| 6| 7| 7| 6| 6| 6| 7| 7| 7| 7| 6| 7| 7|            |
                             DAY ON TEST   | 3| 0| 2| 5| 3| 2| 3| 3| 3| 3| 6| 8| 8| 3| 3| 8| 9| 1| 3| 3| 0| 3| 6| 0| 0|            |
                                           | 5| 6| 7| 6| 5| 0| 4| 4| 5| 5| 4| 7| 1| 4| 5| 7| 6| 4| 5| 4| 6| 5| 4| 6| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|      A     |
    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               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      2  3.0|
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Accessory Spleen                     |                                  X                    X                  |      2     |
      Fibrosis                             |                                              3                           |      1  3.0|
      Hematopoietic Cell Proliferation     |       3                                                                  |      1  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                     1                                   1|      3  1.7|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                                     4                                    |      1  4.0|
      Ulcer                                |                                                                          |      1  3.0|
      Epidermis, Cyst                      |                      3                                                   |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |          4                                                              3|      5  3.4|
      Ventricle, Hydrocephalus             |                                     2                                    |      3  2.3|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +|  48        |
      Foreign Body                         |                               X                          X               |      7  1.0|
      Inflammation, Suppurative            |                               2                          1               |      3  1.3|
      Epiglottis, Metaplasia, Squamous     |                   2                                      1               |      4  1.3|
      Epithelium, Metaplasia, Squamous     |                1  2                                         1            |      6  1.2|
      Glands, Inflammation, Suppurative    |    1           1                                   1                     |      4  1.5|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                 2  1                     |      4  1.8|
      Alveolar Epithelium, Fibrosis        |                                                                          |      2  2.5|
      Alveolar Epithelium, Hyperplasia     |                                                                         2|      3  3.0|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : 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: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 6| 6| 6| 7| 7| 6| 6| 6| 7| 7| 7| 7| 6| 7| 7|            |
                             DAY ON TEST   | 3| 0| 2| 5| 3| 2| 3| 3| 3| 3| 6| 8| 8| 3| 3| 8| 9| 1| 3| 3| 0| 3| 6| 0| 0|            |
                                           | 5| 6| 7| 6| 5| 0| 4| 4| 5| 5| 4| 7| 1| 4| 5| 7| 6| 4| 5| 4| 6| 5| 4| 6| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|      A     |
    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|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
          Cellular, Histiocyte             |                               2                       1  1              2|     11  1.5|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 | 1                    1        2                                          |      5  1.2|
      Foreign Body                         |    X                                                              X      |      5     |
      Inflammation, Suppurative            |    2           2                                                  4      |      5  2.8|
      Olfactory Epithelium, Degeneration   |                                           1                    1         |      2  1.0|
      Respiratory Epithelium, Hyperplasia  |                2                                                         |      1  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        | 1              2     1     1              1                    1  2  2   |      9  1.4|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                             +            |   1        |
      Lens, Cataract                       |                                                             3            |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy, Chronic                 |    3        1     2  3  1     1  1  2  1        2     2  1  2  2  1     1|     30  1.5|
      Pelvis, Dilatation                   |                                                                          |      1  3.0|
      Renal Tubule, Inflammation,          |                                                                          |            |
          Suppurative                      |    2                                                                     |      1  2.0|
      Renal Tubule, Mineralization         |                                              1                           |      5  1.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      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  25                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 6| 5| 7| 7| 7| 7| 6| 7| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 4| 7| 6| 6|             
                             DAY ON TEST   | 3| 2| 3| 4| 8| 3| 3| 3| 3| 2| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 7| 3| 3| 4|             
                                           | 5| 4| 5| 2| 6| 4| 5| 5| 5| 4| 4| 4| 4| 4| 9| 5| 6| 4| 5| 5| 4| 1| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +|             
      Parasite Metazoan                    |                            X                    X                        |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  +  +|             
      Parasite Metazoan                    |       X                             X     X                       X      |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  A  +  +  +  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Clear Cell Focus                     |       X                                                                  |             
      Clear Cell Focus, Multiple           |                                              X                          X|             
      Eosinophilic Focus                   |                                                                          |             
      Hepatodiaphragmatic Nodule           |                                  X     X              X                  |             
      Vacuolization Cytoplasmic            |          3              2           2  2                                 |             
      Hepatocyte, Necrosis                 |                         2                                                |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                  +                    +  +               |             
      Fat, Necrosis                        |                                  3                    2  3               |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                        +                                 |             
      Pharyngeal, Hyperplasia              |                                        4                                 |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    2        2                                                        3   |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tongue                                  | +                                                                        |             
      Epithelium, Hyperplasia              | 3                                                                        |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vacuolization Cytoplasmic            | 2     1  3              1                                                |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 4           3        3                 3     1  2  2                    4|             
      Pars Distalis, Hyperplasia           |                                           2  3     2                     |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  26                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 6| 5| 7| 7| 7| 7| 6| 7| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 4| 7| 6| 6|             
                             DAY ON TEST   | 3| 2| 3| 4| 8| 3| 3| 3| 3| 2| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 7| 3| 3| 4|             
                                           | 5| 4| 5| 2| 6| 4| 5| 5| 5| 4| 4| 4| 4| 4| 9| 5| 6| 4| 5| 5| 4| 1| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS 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                   |                                                                          |             
                                           |                                                                          |             
      C-Cell, Hyperplasia                  |                            2        2  1                                 |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                3                                      3                  |             
      Hyperplasia                          |                                                          1               |             
      Inflammation, Suppurative            |                                              1                           |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                      3                                                   |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Endometrium, Cyst                    |                                                                          |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                                      +   |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                3           3                                      3      |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |             3                                                            |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                  3                                       |             
      Epidermis, Cyst                      |                                  4                                       |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperostosis                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                 2                        |             
      Ventricle, Hydrocephalus             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  27                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 7| 6| 5| 7| 7| 7| 7| 6| 7| 7| 7| 7| 5| 7| 6| 7| 7| 7| 7| 4| 7| 6| 6|             
                             DAY ON TEST   | 3| 2| 3| 4| 8| 3| 3| 3| 3| 2| 3| 3| 3| 3| 4| 3| 4| 3| 3| 3| 3| 7| 3| 3| 4|             
                                           | 5| 4| 5| 2| 6| 4| 5| 5| 5| 4| 4| 4| 4| 4| 9| 5| 6| 4| 5| 5| 4| 1| 5| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS 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                     |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                                                             X        X   |             
      Inflammation, Suppurative            |                                                    3                     |             
      Epiglottis, Metaplasia, Squamous     |                                           1  1     2                     |             
      Epithelium, Hyperplasia              |                                                                      4   |             
      Epithelium, Metaplasia, Squamous     |                      2              1        1     3        1        2   |             
      Glands, Inflammation, Suppurative    |       1     1        1                    1  1              1        1   |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |       2                 1                                                |             
      Alveolar Epithelium, Fibrosis        | 1                                                     1                  |             
      Alveolar Epithelium, Hyperplasia     |       1                             2                                    |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             | 2              2        1           2              1                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |    X                       X                 X                       X   |             
      Inflammation, Suppurative            |    1                       2                 1                           |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                         2|             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         |                                                                         2|             
      Olfactory Epithelium, Degeneration   | 1  2  2  1  1  2  2  2  1  1  1  2  1  1     1  2  1  1  1  1  1  1  2  1|             
      Respiratory Epithelium, Hyperplasia  |                                                                          |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        | 2  2  2        2  3  2  1  1  1  2  1  1  1  1  1  1  1  2  1  1  1  1  1|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
      Lens, Cataract                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 2  1  3  2  2  2  1  1  2  2  3  2  1  2     1     1  2  1  2     1     2|             
      Cortex, Necrosis                     |                            2                                             |             
      Pelvis, Dilatation                   |                                                                          |             
      Renal Tubule, Degeneration           |                                                                          |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                   2                                                      |             
      Renal Tubule, Mineralization         |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  28                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 4| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 6| 7| 6| 7|            |
                             DAY ON TEST   | 8| 7| 3| 4| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 4| 3| 4| 3| 6| 3| 6| 3|            |
                                           | 1| 3| 5| 1| 1| 5| 4| 5| 4| 5| 4| 5| 5| 4| 5| 4| 6| 6| 4| 1| 4| 4| 4| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                                                                          |      2     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                                                                          |      4     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Clear Cell Focus                     |             X     X                                                      |      3     |
      Clear Cell Focus, Multiple           |                                                                          |      2     |
      Eosinophilic Focus                   |                      X                                                   |      1     |
      Hepatodiaphragmatic Nodule           |    X                                X                                    |      5     |
      Vacuolization Cytoplasmic            |          2                                         3     4               |      7  2.6|
      Hepatocyte, Necrosis                 |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +                                 |   4        |
      Fat, Necrosis                        |                                        3                                 |      4  2.8|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +                                      +                                 |   3        |
      Pharyngeal, Hyperplasia              |                                        4                                 |      2  4.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                    2     3               |      5  2.4|
      Ulcer                                |          2                                               4               |      2  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                            +                                             |   2        |
      Epithelium, Hyperplasia              |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |    2                                                              4      |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vacuolization Cytoplasmic            |    2           1  2     1                                   3  2  4      |     11  2.0|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  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  29                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 4| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 6| 7| 6| 7|            |
                             DAY ON TEST   | 8| 7| 3| 4| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 4| 3| 4| 3| 6| 3| 6| 3|            |
                                           | 1| 3| 5| 1| 1| 5| 4| 5| 4| 5| 4| 5| 5| 4| 5| 4| 6| 6| 4| 1| 4| 4| 4| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 | 3  2                                3                                    |     11  2.7|
      Pars Distalis, Hyperplasia           |    3                                   2                                 |      5  2.4|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  |       3                                1        3                        |      6  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                              +                           |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  48        |
      Cyst                                 | 4  3           2  3                          3  3                 4      |      9  3.1|
      Hyperplasia                          |                                                                          |      1  1.0|
      Inflammation, Suppurative            |                                                 3                    3   |      3  2.3|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                            2                                             |      2  2.5|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Endometrium, Cyst                    | 4                                                                        |      1  4.0|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                      +   |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |    +  +                                                  +     +         |   5        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  M  +|  46        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fibrosis                             |                                                                3         |      4  3.0|
      Hematopoietic Cell Proliferation     |                                                                      4   |      1  4.0|
      Hemorrhage                           |    4                                                     2               |      2  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                          |      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  30                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 4| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 6| 7| 6| 7|            |
                             DAY ON TEST   | 8| 7| 3| 4| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 4| 3| 4| 3| 6| 3| 6| 3|            |
                                           | 1| 3| 5| 1| 1| 5| 4| 5| 4| 5| 4| 5| 5| 4| 5| 4| 6| 6| 4| 1| 4| 4| 4| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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               |                                                                          |            |
                                           |                                                                          |            |
      Epidermis, Cyst                      |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperostosis                         |                                                                3         |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Ventricle, Hydrocephalus             |             3                                         3                  |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |                                                                X     X   |      4     |
      Inflammation, Suppurative            |                                  2     1                       1  1  3   |      6  1.8|
      Epiglottis, Metaplasia, Squamous     |                                        1        1                    1   |      6  1.2|
      Epithelium, Hyperplasia              |                                                                          |      1  4.0|
      Epithelium, Metaplasia, Squamous     |                                  2                          1  1  2      |     10  1.6|
      Glands, Inflammation, Suppurative    |                                                             1            |      8  1.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |    2  2                                                                  |      4  1.8|
      Alveolar Epithelium, Fibrosis        |                                                                          |      2  1.0|
      Alveolar Epithelium, Hyperplasia     |                            1                                             |      3  1.3|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |                            1        2                                    |      7  1.6|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |       X                                                                  |      5     |
      Inflammation, Suppurative            |       1           2     2           1  3     2                 1  3      |     11  1.7|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                                                                          |      1  2.0|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         |                                                                          |      1  2.0|
      Olfactory Epithelium, Degeneration   | 1  1  1  1     1  1     1  1  1  2  1  1  2  1  1     2     1  1  2  1  1|     45  1.3|
      Respiratory Epithelium, Hyperplasia  |                         2                                                |      1  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        | 3  1  1        1  2  1  2  1  1     1  3  1  1  1  1  1     1  2  3  1  1|     44  1.4|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES 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  31                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 6| 6| 7| 4| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 5| 7| 6| 7| 6| 7|            |
                             DAY ON TEST   | 8| 7| 3| 4| 1| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 4| 3| 4| 3| 6| 3| 6| 3|            |
                                           | 1| 3| 5| 1| 1| 5| 4| 5| 4| 5| 4| 5| 5| 4| 5| 4| 6| 6| 4| 1| 4| 4| 4| 4| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 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|            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                +                                                         |   1        |
      Lens, Cataract                       |                3                                                         |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy, Chronic                 |       1     2  1  2        1  1  3  2  1  2  2     1  2           1  2   |     36  1.7|
      Cortex, Necrosis                     |                                                                          |      1  2.0|
      Pelvis, Dilatation                   |          4                                                               |      1  4.0|
      Renal Tubule, Degeneration           |          4                                                               |      1  4.0|
      Renal Tubule, Inflammation,          |                                                                          |            |
          Suppurative                      |                                                                          |      1  2.0|
      Renal Tubule, Mineralization         |                   2                                1                     |      2  1.5|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                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  32                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 5| 6| 5| 6| 5| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 4| 5| 7| 6| 6| 6|             
                             DAY ON TEST   | 8| 5| 5| 4| 2| 5| 7| 0| 3| 3| 3| 0| 3| 3| 6| 0| 7| 2| 8| 3| 8| 3| 0| 1| 3|             
                                           | 2| 9| 6| 2| 3| 1| 4| 6| 3| 3| 3| 8| 3| 3| 3| 6| 8| 0| 5| 3| 0| 3| 8| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                 X                        |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                              4                           |             
      Clear Cell Focus                     |                   X                                                      |             
      Eosinophilic Focus                   |                            X                                             |             
      Hepatodiaphragmatic Nodule           |    X  X           X                                      X               |             
      Vacuolization Cytoplasmic            |       3  2  4                    3                    4                  |             
      Bile Duct, Hyperplasia               |                                        2                                 |             
      Hepatocyte, Degeneration, Cystic     |                            4  3                                          |             
      Hepatocyte, Hyperplasia              |                                              4                           |             
      Hepatocyte, Necrosis                 |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +     +                             +              +           +|             
      Fat, Inflammation, Granulomatous     |                                                                          |             
      Fat, Necrosis                        |          3     4                             4              4           2|             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                         2  3  2     2                                    |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Edema                                |                                                       4        3         |             
      Hyperplasia                          |             1                    1                             1         |             
      Ulcer                                |       3                                               3        4         |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |    3                                               2                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +                             +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                      2        2     2                 2                  |             
      Atrium, Thrombosis                   |                                  3                                       |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Vacuolization Cytoplasmic            |                               3        2              3                  |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  33                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 5| 6| 5| 6| 5| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 4| 5| 7| 6| 6| 6|             
                             DAY ON TEST   | 8| 5| 5| 4| 2| 5| 7| 0| 3| 3| 3| 0| 3| 3| 6| 0| 7| 2| 8| 3| 8| 3| 0| 1| 3|             
                                           | 2| 9| 6| 2| 3| 1| 4| 6| 3| 3| 3| 8| 3| 3| 3| 6| 8| 0| 5| 3| 0| 3| 8| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 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                   |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |          3  2  2           2     2     2  3        4              2  3   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M|             
      Hyperplasia                          |                            3                                             |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                        4                                 |             
      Hemorrhage                           |       4                                                                  |             
      Pars Distalis, Hyperplasia           |    3        2                                                            |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |          2                          2                             3      |             
      Follicular Cell, Hyperplasia         |                                                       2                  |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Peritoneum                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                  4                                       |             
      Hyperplasia                          |                   2                                   4                  |             
      Inflammation, Chronic                |                                                                          |             
      Inflammation, Suppurative            |                      4                 2              4     3        4   |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            | 3                    4                                                   |             
      Epithelium, Hyperplasia              |                            2                                             |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |          2                                                               |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Artery, Inflammation                 |                3     3                                                   |             
      Germinal Epithelium, Atrophy         |          4                                            4                  |             
      Interstitial Cell, Hyperplasia       | 3           3                                               3     3      |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +        +              +  +                 +           +        +   |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                          3               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  34                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 5| 6| 5| 6| 5| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 4| 5| 7| 6| 6| 6|             
                             DAY ON TEST   | 8| 5| 5| 4| 2| 5| 7| 0| 3| 3| 3| 0| 3| 3| 6| 0| 7| 2| 8| 3| 8| 3| 0| 1| 3|             
                                           | 2| 9| 6| 2| 3| 1| 4| 6| 3| 3| 3| 8| 3| 3| 3| 6| 8| 0| 5| 3| 0| 3| 8| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Hemorrhage                           |                2                                                         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                         X                                                |             
      Fibrosis                             |                               4        3           3  3           4      |             
      Hemorrhage                           |    3  4                                   4                              |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                      4        4                                         2|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Inflammation, Granulomatous          |                2                                                         |             
      Inflammation, Suppurative            |             4                                               3     4      |             
      Ulcer                                |             4                                                            |             
      Epidermis, Cyst                      |                                                                   4      |             
      Subcutaneous Tissue, Hemorrhage      | 4                                                                        |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |       3                                   4                          4   |             
      Ventricle, Hydrocephalus             |                3                                                         |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |       X                                X                                 |             
      Epithelium, Hyperplasia              |             2                                                            |             
      Epithelium, Metaplasia, Squamous     |                                        2                                 |             
      Glands, Inflammation, Suppurative    |             3                                      1                     |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |             2  1  1              2     2  2                              |             
      Alveolar Epithelium, Foreign Body    |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                         3                                            4   |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             |                               1                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |       1        2  2                                                      |             
      Foreign Body                         |                                                                          |             
      Inflammation, Suppurative            |                                           1                              |             
      Respiratory Epithelium, Hyperplasia  |                                                                          |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  35                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 2| 5| 6| 5| 6| 5| 7| 7| 7| 7| 6| 7| 7| 6| 7| 6| 7| 6| 4| 5| 7| 6| 6| 6|             
                             DAY ON TEST   | 8| 5| 5| 4| 2| 5| 7| 0| 3| 3| 3| 0| 3| 3| 6| 0| 7| 2| 8| 3| 8| 3| 0| 1| 3|             
                                           | 2| 9| 6| 2| 3| 1| 4| 6| 3| 3| 3| 8| 3| 3| 3| 6| 8| 0| 5| 3| 0| 3| 8| 8| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 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                 |                                                                          |             
                                           |                                                                          |             
           Squamous                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pleura                                  | +                                                                        |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                            +     +                                   +   |             
      Cataract                             |                            4     2                                   3   |             
      Cornea, Mineralization               |                                                                          |             
      Lens, Mineralization                 |                            4                                             |             
                                            __________________________________________________________________________|             
   Lacrimal Gland                          |                               +                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                          +               |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 1     2  2  2  4  2  4  2  4  3  2  3  3  3  4     3  4  1  2  3  2  3  2|             
      Pelvis, Transitional Epithelium,     |                                                                          |             
           Hyperplasia                     |                                              3                           |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |    X                                                                     |             
      Inflammation, Suppurative            |                      3                                                   |             
      Transitional Epithelium, Hyperplasia |    2     1           2                                                   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  36                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 7| 4| 6| 6| 6| 6| 6| 6| 5| 7| 6| 7| 4| 7| 5| 5| 6| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 4| 7| 3| 2| 9| 1| 7| 9| 8| 9| 6| 3| 0| 0| 6| 3| 7| 4| 8| 3| 2| 3| 6| 3| 6|            |
                                           | 7| 8| 3| 1| 2| 4| 8| 8| 1| 5| 6| 3| 4| 5| 5| 3| 9| 9| 7| 3| 9| 3| 3| 3| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Parasite Metazoan                    |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Parasite Metazoan                    |          X     X                 X                          X            |      4     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |                                                                      X  X|      2     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                              3                           |      2  3.5|
      Clear Cell Focus                     | X                                                                 X      |      3     |
      Eosinophilic Focus                   |                                                                          |      1     |
      Hepatodiaphragmatic Nodule           |                                  X                                       |      5     |
      Vacuolization Cytoplasmic            | 3                                2  3        2  3                        |     10  2.9|
      Bile Duct, Hyperplasia               |                   3     3                       3                        |      4  2.8|
      Hepatocyte, Degeneration, Cystic     |                                                                          |      2  3.5|
      Hepatocyte, Hyperplasia              |                                                                          |      1  4.0|
      Hepatocyte, Necrosis                 | 3  3                                                                     |      2  3.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |    +                 +  +              +           +           +         |  11        |
      Fat, Inflammation, Granulomatous     |                                                                3         |      1  3.0|
      Fat, Necrosis                        |    3                 3  4              3                       3         |     10  3.3|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |       3        3        3                             1     3            |      9  2.4|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Edema                                |                                        3                                 |      3  3.3|
      Hyperplasia                          | 2                                   2                                    |      5  1.4|
      Ulcer                                | 4                                                                        |      4  3.5|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Necrosis                             |                                                                          |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  41        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |       2                                      2                           |      6  2.0|
      Atrium, Thrombosis                   |                                                 3                        |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 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  37                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 7| 4| 6| 6| 6| 6| 6| 6| 5| 7| 6| 7| 4| 7| 5| 5| 6| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 4| 7| 3| 2| 9| 1| 7| 9| 8| 9| 6| 3| 0| 0| 6| 3| 7| 4| 8| 3| 2| 3| 6| 3| 6|            |
                                           | 7| 8| 3| 1| 2| 4| 8| 8| 1| 5| 6| 3| 4| 5| 5| 3| 9| 9| 7| 3| 9| 3| 3| 3| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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                   |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                2                                                         |      1  2.0|
      Vacuolization Cytoplasmic            |                                                                          |      3  2.7|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                   3        4     3     2     3  3              1  2  3  3|     20  2.6|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                      3                 3                                 |      2  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |    4           2                                                         |      3  3.3|
      Hemorrhage                           |    3                                                                     |      2  3.5|
      Pars Distalis, Hyperplasia           |                                  1              2                        |      4  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  |                                                                          |      3  2.3|
      Follicular Cell, Hyperplasia         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Peritoneum                              |                      +              +                                    |   2        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Granulomatous          |                            2  2                                          |      2  2.0|
      Inflammation, Suppurative            |                                           3                              |      1  3.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                            4                    3                        |      3  3.7|
      Hyperplasia                          | 4                                                        3               |      4  3.3|
      Inflammation, Chronic                |                   3                                                      |      1  3.0|
      Inflammation, Suppurative            |                         4        3     3                    4            |      9  3.4|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                2                       3                                 |      4  3.0|
      Epithelium, Hyperplasia              |                   2                                                      |      2  2.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Artery, Inflammation                 |                                              3                           |      3  3.0|
      Germinal Epithelium, Atrophy         |       4              3                       4  4              4         |      7  3.9|
      Interstitial Cell, Hyperplasia       |             1           2                                               3|      7  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  38                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 7| 4| 6| 6| 6| 6| 6| 6| 5| 7| 6| 7| 4| 7| 5| 5| 6| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 4| 7| 3| 2| 9| 1| 7| 9| 8| 9| 6| 3| 0| 0| 6| 3| 7| 4| 8| 3| 2| 3| 6| 3| 6|            |
                                           | 7| 8| 3| 1| 2| 4| 8| 8| 1| 5| 6| 3| 4| 5| 5| 3| 9| 9| 7| 3| 9| 3| 3| 3| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |                +  +  +  +     +     +              +           +         |  15        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  M  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Lymphoid                |          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accessory Spleen                     |                                                                          |      1     |
      Fibrosis                             |                      1  3        3     3                    3            |     10  3.0|
      Hemorrhage                           |                                                                          |      3  3.7|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                                                          4           4   |      5  3.6|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |    2                                                     4               |      2  3.0|
      Inflammation, Granulomatous          |                   3                                                      |      2  2.5|
      Inflammation, Suppurative            |                                                                          |      3  3.7|
      Ulcer                                |                                                                          |      1  4.0|
      Epidermis, Cyst                      |    2                                                        4           4|      4  3.5|
      Subcutaneous Tissue, Hemorrhage      |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                         4                                                |      4  3.8|
      Ventricle, Hydrocephalus             |                                           3                 3            |      3  3.0|
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |                                                             X            |      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  39                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 7| 4| 6| 6| 6| 6| 6| 6| 5| 7| 6| 7| 4| 7| 5| 5| 6| 7| 7| 7| 6| 7| 6|            |
                             DAY ON TEST   | 4| 7| 3| 2| 9| 1| 7| 9| 8| 9| 6| 3| 0| 0| 6| 3| 7| 4| 8| 3| 2| 3| 6| 3| 6|            |
                                           | 7| 8| 3| 1| 2| 4| 8| 8| 1| 5| 6| 3| 4| 5| 5| 3| 9| 9| 7| 3| 9| 3| 3| 3| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Epithelium, Hyperplasia              |                                                                          |      1  2.0|
      Epithelium, Metaplasia, Squamous     |                                                                          |      1  2.0|
      Glands, Inflammation, Suppurative    |                                                             3  3         |      4  2.5|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                           1                              |      7  1.6|
      Alveolar Epithelium, Foreign Body    |                                  X                                       |      1     |
      Alveolar Epithelium, Hyperplasia     | 2                                3                                   1   |      5  2.6|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |                2                                                         |      2  1.5|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                  2                    2                  |      5  1.8|
      Foreign Body                         |                X     X                          X              X  X      |      5     |
      Inflammation, Suppurative            |                      3                       3                 4  2      |      5  2.6|
      Respiratory Epithelium, Hyperplasia  |                      2                                         2         |      2  2.0|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                                              2                           |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pleura                                  |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                       +                  |   4        |
      Cataract                             |                                                                          |      3  3.0|
      Cornea, Mineralization               |                                                       3                  |      1  3.0|
      Lens, Mineralization                 |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lacrimal Gland                          |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                     +                                    |   2        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy, Chronic                 | 4  1  3     2  1  3  3  4  3  2  3  1  4  3  4  3  2  3  2  3  2  3  4  1|     47  2.7|
      Pelvis, Transitional Epithelium,     |                                                                          |            |
           Hyperplasia                     |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Calculus Micro Observation Only      |                                                                          |      1     |
      Inflammation, Suppurative            |                                                                          |      1  3.0|
      Transitional Epithelium, Hyperplasia |                                        2                                 |      4  1.8|
 __________________________________________________________________________________________________________________________________ 
  * : 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  40                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 5| 6| 6| 6| 7| 6| 6| 6| 7| 6| 6| 6| 6| 7| 7| 6| 7| 1| 6| 5| 7|             
                             DAY ON TEST   | 3| 1| 3| 2| 4| 0| 1| 0| 3| 6| 1| 7| 3| 7| 8| 9| 6| 3| 3| 1| 3| 8| 6| 8| 0|             
                                           | 3| 5| 6| 8| 0| 8| 6| 5| 3| 7| 4| 9| 3| 8| 7| 2| 4| 3| 3| 6| 3| 4| 7| 0| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                       X                  |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                 X                        |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |          3              4           2                                3   |             
      Basophilic Focus                     |                                                    X                     |             
      Clear Cell Focus                     |                                  X                 X                     |             
      Hepatodiaphragmatic Nodule           | X                                                           X            |             
      Vacuolization Cytoplasmic            |                            3                                             |             
      Bile Duct, Hyperplasia               | 4                                                                        |             
      Hepatocyte, Degeneration, Cystic     |                               2     2                       3     4      |             
      Hepatocyte, Hyperplasia              |                                                                          |             
      Hepatocyte, Necrosis                 |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                   +                    +                 +  +            |             
      Fat, Hemorrhage                      |                                                                          |             
      Fat, Inflammation, Granulomatous     |                                        4                                 |             
      Fat, Necrosis                        |                   4                                      3  3            |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |       +                 +                                                |             
      Cyst                                 |       3                                                                  |             
      Pharyngeal, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                   1                                3  3           2      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    1              1              2     2  2                              |             
      Inflammation, Suppurative            |                                                                          |             
      Necrosis                             |                                                                          |             
      Ulcer                                | 4                          4           4                                 |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                         3|             
      Ulcer                                |                                                                         3|             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                +         |             
      Developmental Malformation           |                                                                X         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 5| 6| 6| 6| 7| 6| 6| 6| 7| 6| 6| 6| 6| 7| 7| 6| 7| 1| 6| 5| 7|             
                             DAY ON TEST   | 3| 1| 3| 2| 4| 0| 1| 0| 3| 6| 1| 7| 3| 7| 8| 9| 6| 3| 3| 1| 3| 8| 6| 8| 0|             
                                           | 3| 5| 6| 8| 0| 8| 6| 5| 3| 7| 4| 9| 3| 8| 7| 2| 4| 3| 3| 6| 3| 4| 7| 0| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Cardiomyopathy                       |                                                                          |             
      Atrium, Thrombosis                   |                   3                                                      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                      3                                                   |             
      Hyperplasia                          |                                                                          |             
      Vacuolization Cytoplasmic            |                            2                                             |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    4              4     2     4        1  2  3  4  2        4     2      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                       3  4               |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                           3                              |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                      3                                                   |             
      Hemorrhage                           |          4                    4                                          |             
      Pars Distalis, Hyperplasia           |             3        3                       3     2     3        4  3   |             
      Pars Distalis, Hypertrophy           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |                   4        3                       4                     |             
      Follicular Cell, Hyperplasia         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |          3     3        2        3                       4              2|             
      Hyperplasia                          |                                              3                           |             
      Inflammation, Suppurative            |          3                                                              3|             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |          3                 4              3                              |             
      Epithelium, Hyperplasia              |                         1                                                |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                            4                                             |             
      Epithelium, Hyperplasia              |                            4                                             |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Germinal Epithelium, Atrophy         |          4                             4                                 |             
      Interstitial Cell, Hyperplasia       |                                                                      2   |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  42                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 5| 6| 6| 6| 7| 6| 6| 6| 7| 6| 6| 6| 6| 7| 7| 6| 7| 1| 6| 5| 7|             
                             DAY ON TEST   | 3| 1| 3| 2| 4| 0| 1| 0| 3| 6| 1| 7| 3| 7| 8| 9| 6| 3| 3| 1| 3| 8| 6| 8| 0|             
                                           | 3| 5| 6| 8| 0| 8| 6| 5| 3| 7| 4| 9| 3| 8| 7| 2| 4| 3| 3| 6| 3| 4| 7| 0| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                  +           +                          +|             
      Iliac, Ectasia                       |                                                                         4|             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                3         |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                2         |             
      Hyperplasia, Histiocytic             |                                                          4               |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |                                  X                                       |             
      Angiectasis                          |                                  4                                       |             
      Fibrosis                             |    3  2  3  3  3        3                                         2     3|             
      Hemorrhage                           |                                                                          |             
      Necrosis                             |                                              4                           |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |          1                          4  3        4  4        4     4      |             
      Hyperplasia                          |                                     3                                    |             
      Ulcer                                |                                              4                           |             
      Epidermis, Cyst                      | 3                                                                        |             
      Sebaceous Gland, Hyperplasia         | 3                                                                        |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cranium, Fibrosis                    |                                                                          |             
      Cranium, Inflammation, Granulomatous |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                          +               |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           | 4  2           2     4                                                   |             
      Ventricle, Hydrocephalus             |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |             +                                                            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |       X                 X                                                |             
      Inflammation, Suppurative            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  43                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 7| 5| 6| 6| 6| 7| 6| 6| 6| 7| 6| 6| 6| 6| 7| 7| 6| 7| 1| 6| 5| 7|             
                             DAY ON TEST   | 3| 1| 3| 2| 4| 0| 1| 0| 3| 6| 1| 7| 3| 7| 8| 9| 6| 3| 3| 1| 3| 8| 6| 8| 0|             
                                           | 3| 5| 6| 8| 0| 8| 6| 5| 3| 7| 4| 9| 3| 8| 7| 2| 4| 3| 3| 6| 3| 4| 7| 0| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                 |                                                                          |             
                                           |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
      Epithelium, Metaplasia, Squamous     |                         1                                                |             
      Glands, Inflammation, Suppurative    |       1  2              1     1                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |       2                                                                  |             
      Alveolar Epithelium, Fibrosis        | 3                                                        2               |             
      Alveolar Epithelium, Hyperplasia     |                               2        3     2        3                  |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             |                               3        3     3           4        2  3   |             
      Bronchiole, Bronchus, Interstitium,  |                                                                          |             
           Fibrosis                        |                                                                          |             
      Interstitium, Mineralization         |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |          2                                                              2|             
      Foreign Body                         |    X                                                        X            |             
      Inflammation, Suppurative            |                                                                          |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |    I                    +                                                |             
      Lens, Cataract                       |                         3                                                |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 3  3  1  3  2  2  2  2  3  4  2  4  3  3  4  2  2  2  4  2  4     2  1  4|             
      Cortex, Necrosis                     |                                                                          |             
      Renal Tubule, Hyperplasia            |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |             X                                                            |             
      Inflammation, Suppurative            |                                                                          |             
      Ulcer                                |                                                                          |             
      Transitional Epithelium, Hyperplasia |                            4                                             |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  44                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 6| 7| 7| 5| 7| 7| 6| 6| 7| 7| 6| 5| 6| 3| 7| 7| 6| 6| 6| 4| 5| 5|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 3| 9| 1| 3| 7| 0| 3| 3| 6| 7| 7| 8| 3| 3| 8| 4| 1| 0| 7| 5|            |
                                           | 3| 5| 3| 8| 3| 3| 4| 6| 3| 9| 1| 3| 3| 3| 9| 4| 4| 3| 3| 7| 4| 4| 3| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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                               | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |                                                             X            |      2     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | M  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Parasite Metazoan                    |       X                             X                 X                  |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          | 3                                   2                                    |      6  2.8|
      Basophilic Focus                     |                                     X                                    |      2     |
      Clear Cell Focus                     |                                                                          |      2     |
      Hepatodiaphragmatic Nodule           |                                                          X     X         |      4     |
      Vacuolization Cytoplasmic            |    4              2                    3        4        4               |      6  3.3|
      Bile Duct, Hyperplasia               |    4                                                                     |      2  4.0|
      Hepatocyte, Degeneration, Cystic     |                                                          3               |      5  2.8|
      Hepatocyte, Hyperplasia              | 3  3                                                                     |      2  3.0|
      Hepatocyte, Necrosis                 |             3                                            3               |      2  3.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |          +  +           +              +     +     +                 +  +|  12        |
      Fat, Hemorrhage                      |                                                                         4|      1  4.0|
      Fat, Inflammation, Granulomatous     |                                                                          |      1  4.0|
      Fat, Necrosis                        |          4  2           3              3     3     3                 4   |     10  3.2|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                      +                                                   |   3        |
      Cyst                                 |                                                                          |      1  3.0|
      Pharyngeal, Hyperplasia              |                      4                                                   |      1  4.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  M|  48        |
      Atrophy                              | 2  2        2                       2                                    |      8  2.1|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |    3                                                           3  3  2   |      9  2.1|
      Inflammation, Suppurative            |                                                                      3   |      1  3.0|
      Necrosis                             |          2                                                               |      1  2.0|
      Ulcer                                |                                                          2     4         |      5  3.6|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                                                                          |      1  3.0|
      Ulcer                                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   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  45                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 6| 7| 7| 5| 7| 7| 6| 6| 7| 7| 6| 5| 6| 3| 7| 7| 6| 6| 6| 4| 5| 5|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 3| 9| 1| 3| 7| 0| 3| 3| 6| 7| 7| 8| 3| 3| 8| 4| 1| 0| 7| 5|            |
                                           | 3| 5| 3| 8| 3| 3| 4| 6| 3| 9| 1| 3| 3| 3| 9| 4| 4| 3| 3| 7| 4| 4| 3| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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 - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Developmental Malformation           |                                                                          |      1     |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cardiomyopathy                       |                      2                                                   |      1  2.0|
      Atrium, Thrombosis                   |                                                                      2   |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Hyperplasia                          |                            3                                             |      1  3.0|
      Vacuolization Cytoplasmic            |    3        4           2                             3  2               |      6  2.7|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |    2           2  2                 4  2                                 |     16  2.8|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                                           2                              |      3  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  M  +|  48        |
      Hyperplasia                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                                                                   3      |      2  3.0|
      Hemorrhage                           |                                  4        1                              |      4  3.3|
      Pars Distalis, Hyperplasia           | 3        2                                                               |      9  2.9|
      Pars Distalis, Hypertrophy           |                            2                                             |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Hyperplasia                  |             3                          2                                 |      5  3.2|
      Follicular Cell, Hyperplasia         |                                           2                              |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |    4                                         3                 3        4|     10  3.1|
      Hyperplasia                          |                                                                          |      1  3.0|
      Inflammation, Suppurative            |                                              3                           |      3  3.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                   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  46                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 6| 7| 7| 5| 7| 7| 6| 6| 7| 7| 6| 5| 6| 3| 7| 7| 6| 6| 6| 4| 5| 5|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 3| 9| 1| 3| 7| 0| 3| 3| 6| 7| 7| 8| 3| 3| 8| 4| 1| 0| 7| 5|            |
                                           | 3| 5| 3| 8| 3| 3| 4| 6| 3| 9| 1| 3| 3| 3| 9| 4| 4| 3| 3| 7| 4| 4| 3| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Epithelium, Hyperplasia              |                                                    2  3                  |      3  2.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                                                                          |      1  4.0|
      Epithelium, Hyperplasia              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Germinal Epithelium, Atrophy         |    2        3           4              3                                 |      6  3.3|
      Interstitial Cell, Hyperplasia       |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |          +  +     +  +     +                                +           +|  10        |
      Iliac, Ectasia                       |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  M  +  A  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia, Histiocytic             |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Accessory Spleen                     |                                                                          |      1     |
      Angiectasis                          |                                                                          |      1  4.0|
      Fibrosis                             | 4           2           4        3  3  2     3     2  3  4               |     18  2.9|
      Hemorrhage                           |                                                                         4|      1  4.0|
      Necrosis                             |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Epithelium, Hyperplasia              |                                     3                                    |      1  3.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Acanthosis                           | 3                                                                        |      1  3.0|
      Hyperkeratosis                       |       4           4  3              3                    4           3   |     13  3.5|
      Hyperplasia                          | 3                    3              2                 4                  |      5  3.0|
      Ulcer                                |                                                                          |      1  4.0|
      Epidermis, Cyst                      |                                                                          |      1  3.0|
      Sebaceous Gland, Hyperplasia         |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 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  47                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 6| 7| 7| 5| 7| 7| 6| 6| 7| 7| 6| 5| 6| 3| 7| 7| 6| 6| 6| 4| 5| 5|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 3| 9| 1| 3| 7| 0| 3| 3| 6| 7| 7| 8| 3| 3| 8| 4| 1| 0| 7| 5|            |
                                           | 3| 5| 3| 8| 3| 3| 4| 6| 3| 9| 1| 3| 3| 3| 9| 4| 4| 3| 3| 7| 4| 4| 3| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    |    +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Cranium, Fibrosis                    |                                                                3         |      1  3.0|
      Cranium, Inflammation, Granulomatous |                                                                4  3      |      2  3.5|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |          3     1        3  2  2                                          |      9  2.6|
      Ventricle, Hydrocephalus             |                   3                                                      |      1  3.0|
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Foreign Body                         |                                                          X        X      |      4     |
      Inflammation, Suppurative            |                                                                   2      |      1  2.0|
      Epithelium, Hyperplasia              | 2                                                                        |      1  2.0|
      Epithelium, Metaplasia, Squamous     |                                  2                       3               |      3  2.0|
      Glands, Inflammation, Suppurative    | 2                                                                    1   |      6  1.3|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hemorrhage                           |                                           3  2                           |      3  2.3|
      Alveolar Epithelium, Fibrosis        |                1     1                                   2               |      5  1.8|
      Alveolar Epithelium, Hyperplasia     |             4  2        1                                4  2            |      9  2.6|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |             3  1                                         2  2            |     10  2.6|
      Bronchiole, Bronchus, Interstitium,  |                                                                          |            |
           Fibrosis                        |                      3                                                   |      1  3.0|
      Interstitium, Mineralization         |                      2                                                   |      1  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                                           2                              |      3  2.0|
      Foreign Body                         |                   X                 X                    X               |      5     |
      Inflammation, Suppurative            |                   2                                      2        4      |      3  2.7|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                                                                2         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
      Lens, Cataract                       |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   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  48                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 6| 7| 7| 5| 7| 7| 6| 6| 7| 7| 6| 5| 6| 3| 7| 7| 6| 6| 6| 4| 5| 5|            |
                             DAY ON TEST   | 3| 3| 3| 1| 3| 3| 9| 1| 3| 7| 0| 3| 3| 6| 7| 7| 8| 3| 3| 8| 4| 1| 0| 7| 5|            |
                                           | 3| 5| 3| 8| 3| 3| 4| 6| 3| 9| 1| 3| 3| 3| 9| 4| 4| 3| 3| 7| 4| 4| 3| 5| 4|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Nephropathy, Chronic                 | 3  2  1  2  3  2  4  3  3  2     3  4  1  2  2  3  3  3  4  1  4  1  3  1|     48  2.6|
      Cortex, Necrosis                     |                                           3                              |      1  3.0|
      Renal Tubule, Hyperplasia            |                                                    4                     |      1  4.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  I  +  +|  48        |
      Calculus Micro Observation Only      |                                                                          |      1     |
      Inflammation, Suppurative            |                                                                2         |      1  2.0|
      Ulcer                                |                                                 4                        |      1  4.0|
      Transitional Epithelium, Hyperplasia |                                                                2         |      2  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  49                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 6| 7| 5| 5| 7| 5| 6| 4| 5| 7| 5| 5| 5| 7| 6| 5| 6| 6| 5| 6| 4| 4|             
                             DAY ON TEST   | 6| 6| 3| 0| 3| 8| 9| 0| 0| 9| 8| 3| 3| 7| 4| 8| 2| 5| 2| 3| 2| 5| 1| 4| 7|             
                                           | 8| 8| 3| 1| 3| 0| 0| 6| 2| 2| 6| 8| 3| 8| 1| 6| 0| 0| 3| 6| 5| 2| 6| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Parasite Metazoan                    |                                           X        X                     |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |       X                                                                  |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |       4                    3                                             |             
      Basophilic Focus                     |             X                                                            |             
      Hepatodiaphragmatic Nodule           |                                        X                                X|             
      Inflammation, Granulomatous          |                                                                          |             
      Mixed Cell Focus                     |                            X                                             |             
      Thrombosis                           |                                     4                                    |             
      Vacuolization Cytoplasmic            |          4                                               3               |             
      Bile Duct, Hyperplasia               |             2                                                            |             
      Hepatocyte, Degeneration, Cystic     |                                     3                                    |             
      Hepatocyte, Hyperplasia              |                               4                                          |             
      Hepatocyte, Necrosis                 |                                     3                                    |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +        +                                   +     +               |             
      Fat, Necrosis                        |       3        2                                   3     3               |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |       +                                                                  |             
      Gingival, Hyperplasia                |       4                                                                  |             
      Pharyngeal, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              | 2     2     1  1                          1     2                 2      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |          3                                                               |             
      Hyperplasia                          | 1        3           1  1  1        2        2  2                    1   |             
      Inflammation, Suppurative            |          3                          3                                    |             
      Ulcer                                | 2        4              3           3        4                       3   |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Thrombosis                           |                                                                          |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |    +                                                                     |             
      Inflammation, Suppurative            |    4                                                                     |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  50                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 6| 7| 5| 5| 7| 5| 6| 4| 5| 7| 5| 5| 5| 7| 6| 5| 6| 6| 5| 6| 4| 4|             
                             DAY ON TEST   | 6| 6| 3| 0| 3| 8| 9| 0| 0| 9| 8| 3| 3| 7| 4| 8| 2| 5| 2| 3| 2| 5| 1| 4| 7|             
                                           | 8| 8| 3| 1| 3| 0| 0| 6| 2| 2| 6| 8| 3| 8| 1| 6| 0| 0| 3| 6| 5| 2| 6| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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 - cont                  |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                                                          |             
      Atrium, Thrombosis                   |                                              2                           |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vacuolization Cytoplasmic            |       3  2                          2                                    |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                      3                       2  3        2  2            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                            4                    3                        |             
      Hemorrhage                           |                                  4                                       |             
      Pars Distalis, Hyperplasia           | 2  2                                                                 2   |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |                                  3                 3     3  2            |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Thrombosis, Acute                    |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                     3  3     4           4               |             
      Hyperplasia                          |                                              4                           |             
      Inflammation, Chronic                |       4                                                                  |             
      Inflammation, Suppurative            |                            4  4                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                3  3                                2                     |             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Artery, Inflammation                 |                                                                          |             
      Germinal Epithelium, Atrophy         |       4                    3  4     4           3                        |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  51                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 6| 7| 5| 5| 7| 5| 6| 4| 5| 7| 5| 5| 5| 7| 6| 5| 6| 6| 5| 6| 4| 4|             
                             DAY ON TEST   | 6| 6| 3| 0| 3| 8| 9| 0| 0| 9| 8| 3| 3| 7| 4| 8| 2| 5| 2| 3| 2| 5| 1| 4| 7|             
                                           | 8| 8| 3| 1| 3| 0| 0| 6| 2| 2| 6| 8| 3| 8| 1| 6| 0| 0| 3| 6| 5| 2| 6| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Interstitial Cell, Hyperplasia       | 3                       2                                               2|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Reticulum Cell          |                                                             4            |             
                                            __________________________________________________________________________|             
   Lymph Node                              |       +              +        +                 +                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Spleen                     |       X                                                                  |             
      Fibrosis                             |                            3        3        2                 3         |             
      Hemorrhage                           |                                                 4                        |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectopic Parathyroid Gland            |                            3                                             |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                                                          |             
      Ulcer                                |       2                                                                  |             
      Epidermis, Cyst                      |                                                                          |             
      Sebaceous Gland, Cyst                |                                                                          |             
      Subcutaneous Tissue, Edema           |                                                                          |             
      Subcutaneous Tissue, Epidermis, Cyst |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                         4        3                                       |             
      Ventricle, Hydrocephalus             |          2        2                                   2  3  3           3|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                      +   |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  52                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 7| 6| 7| 5| 5| 7| 5| 6| 4| 5| 7| 5| 5| 5| 7| 6| 5| 6| 6| 5| 6| 4| 4|             
                             DAY ON TEST   | 6| 6| 3| 0| 3| 8| 9| 0| 0| 9| 8| 3| 3| 7| 4| 8| 2| 5| 2| 3| 2| 5| 1| 4| 7|             
                                           | 8| 8| 3| 1| 3| 0| 0| 6| 2| 2| 6| 8| 3| 8| 1| 6| 0| 0| 3| 6| 5| 2| 6| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
      Foreign Body                         |       X              X                                                   |             
      Epithelium, Hyperplasia              |                                                                          |             
      Epithelium, Metaplasia, Squamous     |                                     2                                    |             
      Glands, Inflammation, Suppurative    |       1        3     2           2  2                                    |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           | 2     2                       2  2        2                              |             
      Inflammation, Granulomatous          |                                                 4                        |             
      Alveolar Epithelium, Foreign Body    |                                                 X                        |             
      Alveolar Epithelium, Hyperplasia     |                   1                                               2      |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
          Cellular, Histiocyte             |          2        1                                         2  4  2      |             
      Alveolar Epithelium, Pigmentation    |                                                                4         |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |             2     1                       1     1                        |             
      Foreign Body                         |       X                             X                                    |             
      Inflammation, Suppurative            |       1        1     2              2                                    |             
      Nasopharyngeal Duct, Hyperplasia     |                                                          3               |             
      Olfactory Epithelium, Degeneration   |       1                                                                  |             
      Respiratory Epithelium, Hyperplasia  |                                                                   2  2   |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        | 1  1                 2                                                   |             
                                            __________________________________________________________________________|             
   Pleura                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                      +   |             
      Cataract                             |                                                                      3   |             
      Lens, Cataract                       |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 1  1  3  4  2  1  2     2  4  1  2  4  2  1  2  2  1  1  2  2  3  3  2  2|             
      Artery, Inflammation                 |                                                                   4      |             
      Artery, Necrosis, Fibrinoid          |                                                                   4      |             
      Cortex, Cyst                         |                                                                          |             
      Renal Tubule, Hyperplasia, Atypical  |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Calculus Micro Observation Only      |                                                                          |             
      Hemorrhage                           |             2                                                            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  53                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 5| 7| 7| 5| 5| 6| 7| 4| 6| 6| 7| 6| 7| 5| 7| 7| 6| 4| 6| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 2| 6| 1| 3| 1| 7| 8| 0| 6| 3| 7| 3| 1| 0| 8| 3| 3| 2| 6|            |
                                           | 3| 3| 1| 9| 3| 3| 0| 8| 7| 3| 9| 9| 6| 0| 4| 3| 6| 3| 5| 7| 9| 6| 3| 0| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  49        |
      Inflammation, Suppurative            |                            3                                             |      1  3.0|
      Parasite Metazoan                    |                                        X                                 |      3     |
      Ulcer                                |                            3                                             |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Parasite Metazoan                    |             X                             X                       X      |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Parasite Metazoan                    |                                              X                 X         |      3     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  48        |
      Diverticulum                         |                               X                                          |      1     |
      Epithelium, Hyperplasia              |                               4                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |             2                             3                              |      4  3.0|
      Basophilic Focus                     |                                                                          |      1     |
      Hepatodiaphragmatic Nodule           |       X        X           X                                             |      5     |
      Inflammation, Granulomatous          |                                                             3     3      |      2  3.0|
      Mixed Cell Focus                     |                                                                          |      1     |
      Thrombosis                           |                                                                          |      1  4.0|
      Vacuolization Cytoplasmic            |                   4     4           4                    3               |      6  3.7|
      Bile Duct, Hyperplasia               |       3                                               4                  |      3  3.0|
      Hepatocyte, Degeneration, Cystic     |    3           2                 2     1                                 |      5  2.2|
      Hepatocyte, Hyperplasia              |                         4                                                |      2  4.0|
      Hepatocyte, Necrosis                 |          3        2                 2                                    |      4  2.5|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                      +              +           +     +                  |   8        |
      Fat, Necrosis                        |                      3                          4     4                  |      7  3.1|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                +                                                         |   2        |
      Gingival, Hyperplasia                |                                                                          |      1  4.0|
      Pharyngeal, Hyperplasia              |                4                                                         |      1  4.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |       3                                      3     2              2      |     11  1.9|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                         3                             3                  |      3  3.0|
      Hyperplasia                          |                         3                 2     2     1              2  2|     15  1.7|
      Inflammation, Suppurative            |                                                                          |      2  3.0|
      Ulcer                                |                         4                 4                             4|      9  3.4|
 __________________________________________________________________________________________________________________________________ 
  * : 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  54                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 5| 7| 7| 5| 5| 6| 7| 4| 6| 6| 7| 6| 7| 5| 7| 7| 6| 4| 6| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 2| 6| 1| 3| 1| 7| 8| 0| 6| 3| 7| 3| 1| 0| 8| 3| 3| 2| 6|            |
                                           | 3| 3| 1| 9| 3| 3| 0| 8| 7| 3| 9| 9| 6| 0| 4| 3| 6| 3| 5| 7| 9| 6| 3| 0| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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 - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Thrombosis                           |                                                                         3|      1  3.0|
      Ulcer                                |                                                          4               |      1  4.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   1        |
      Inflammation, Suppurative            |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       |          2  2                                            3               |      3  2.3|
      Atrium, Thrombosis                   |                                  4  4                    2               |      4  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vacuolization Cytoplasmic            |             2                                   3  2                     |      6  2.3|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |       3  2  3  3        3              2                       4         |     12  2.7|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                         3                                                |      1  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |                                                                          |      2  3.5|
      Hemorrhage                           |                      4           4                                       |      3  4.0|
      Pars Distalis, Hyperplasia           |                               1                       3                  |      5  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  | 1           2                       2     2                              |      8  2.3|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Granulomatous          |                                                                   4      |      1  4.0|
      Epithelium, Hyperplasia              |                                                                   3      |      1  3.0|
                                            __________________________________________________________________________|____________|
   Penis                                   |       +                                                                  |   1        |
      Hemorrhage                           |       4                                                                  |      1  4.0|
      Thrombosis, Acute                    |       4                                                                  |      1  4.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 | 3                 2     3                 3              4        3  3   |     11  3.2|
 __________________________________________________________________________________________________________________________________ 
  * : 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  55                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 5| 7| 7| 5| 5| 6| 7| 4| 6| 6| 7| 6| 7| 5| 7| 7| 6| 4| 6| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 2| 6| 1| 3| 1| 7| 8| 0| 6| 3| 7| 3| 1| 0| 8| 3| 3| 2| 6|            |
                                           | 3| 3| 1| 9| 3| 3| 0| 8| 7| 3| 9| 9| 6| 0| 4| 3| 6| 3| 5| 7| 9| 6| 3| 0| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia                          |             4                                                            |      2  4.0|
      Inflammation, Chronic                |                                                                          |      1  4.0|
      Inflammation, Suppurative            | 3     3                                3           3     4        3      |      8  3.4|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                      2   |      4  2.5|
      Epithelium, Hyperplasia              |                                        2                             3   |      2  2.5|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Artery, Inflammation                 |                3                                                         |      1  3.0|
      Germinal Epithelium, Atrophy         |                4        2                                            3   |      8  3.4|
      Interstitial Cell, Hyperplasia       |                                           1        1                     |      5  1.8|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Reticulum Cell          |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +                                                  +               |   6        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Fibrosis                             |          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  44        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fibrosis                             |          2                                                               |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fibrosis                             |          2                                                               |      1  2.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accessory Spleen                     |                                                                          |      1     |
      Fibrosis                             |    3     4  3  4                                   3                     |      9  3.1|
      Hemorrhage                           |                                                                          |      1  4.0|
      Necrosis                             |                                                       4                 4|      2  4.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Ectopic Parathyroid Gland            |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Galactocele                          |                3                                                         |      1  3.0|
      Epithelium, Hyperplasia              |                2                                                         |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                                  3              2                        |      2  2.5|
      Ulcer                                |       3                                                  1               |      3  2.0|
      Epidermis, Cyst                      |                                              4                           |      1  4.0|
 __________________________________________________________________________________________________________________________________ 
  * : 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  56                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 5| 7| 7| 5| 5| 6| 7| 4| 6| 6| 7| 6| 7| 5| 7| 7| 6| 4| 6| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 2| 6| 1| 3| 1| 7| 8| 0| 6| 3| 7| 3| 1| 0| 8| 3| 3| 2| 6|            |
                                           | 3| 3| 1| 9| 3| 3| 0| 8| 7| 3| 9| 9| 6| 0| 4| 3| 6| 3| 5| 7| 9| 6| 3| 0| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Sebaceous Gland, Cyst                |                                                                   3      |      1  3.0|
      Subcutaneous Tissue, Edema           |                                  4                                       |      1  4.0|
      Subcutaneous Tissue, Epidermis, Cyst |                                              4                           |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |          3           4                                4                 4|      6  3.7|
      Ventricle, Hydrocephalus             |                   3                                         2            |      8  2.5|
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Foreign Body                         |                                                                         X|      3     |
      Epithelium, Hyperplasia              |                                                                         2|      1  2.0|
      Epithelium, Metaplasia, Squamous     |                                                                          |      1  2.0|
      Glands, Inflammation, Suppurative    |                                                                   2      |      6  2.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           | 1                          1     2                                       |      8  1.8|
      Inflammation, Granulomatous          |                                                                          |      1  4.0|
      Alveolar Epithelium, Foreign Body    |                                                                          |      1     |
      Alveolar Epithelium, Hyperplasia     |                                  2              1                        |      4  1.5|
      Alveolar Epithelium, Infiltration    |                                                                          |            |
          Cellular, Histiocyte             |    1                             2              3                        |      8  2.1|
      Alveolar Epithelium, Pigmentation    |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |       2     1                                            1               |      7  1.3|
      Foreign Body                         |    X                                            X                        |      4     |
      Inflammation, Suppurative            |                                                 4                       2|      6  2.0|
      Nasopharyngeal Duct, Hyperplasia     |                                                                          |      1  3.0|
      Olfactory Epithelium, Degeneration   |                            1                    4                        |      3  2.0|
      Respiratory Epithelium, Hyperplasia  |    3                                                                     |      3  2.3|
      Respiratory Epithelium, Metaplasia,  |                                                                          |            |
           Squamous                        |                2        2           2     1  1  2                       1|     10  1.5|
                                            __________________________________________________________________________|____________|
   Pleura                                  |                                     +                                    |   1        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES 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  57                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 5| 7| 7| 5| 5| 6| 7| 4| 6| 6| 7| 6| 7| 5| 7| 7| 6| 4| 6| 7| 7| 6|            |
                             DAY ON TEST   | 3| 3| 0| 3| 3| 3| 2| 6| 1| 3| 1| 7| 8| 0| 6| 3| 7| 3| 1| 0| 8| 3| 3| 2| 6|            |
                                           | 3| 3| 1| 9| 3| 3| 0| 8| 7| 3| 9| 9| 6| 0| 4| 3| 6| 3| 5| 7| 9| 6| 3| 0| 6|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                +  +  +                          +                        |   5        |
      Cataract                             |                4                                                         |      2  3.5|
      Lens, Cataract                       |                                                 3                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                      +                                                   |   1        |
      Hyperplasia                          |                      3                                                   |      1  3.0|
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                             +            |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Nephropathy, Chronic                 | 3  3  2  1  4  4  3  2  3  1     2  3  4  4  4  2  3  2  2  2  2  2  3  2|     48  2.4|
      Artery, Inflammation                 |                                                                          |      1  4.0|
      Artery, Necrosis, Fibrinoid          |                                                                          |      1  4.0|
      Cortex, Cyst                         |                                           4                              |      1  4.0|
      Renal Tubule, Hyperplasia, Atypical  |                                              4                           |      1  4.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Calculus Micro Observation Only      |                               X                                          |      1     |
      Hemorrhage                           |                                                                         4|      2  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  58                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 6| 4| 7| 6| 5| 6| 5| 4| 7| 5| 6| 5| 7| 7| 4| 6| 5| 4| 6| 4| 6| 6| 5|             
                             DAY ON TEST   | 3| 6| 3| 6| 3| 0| 8| 3| 4| 9| 3| 5| 3| 8| 3| 2| 4| 3| 8| 9| 5| 6| 6| 5| 7|             
                                           | 6| 4| 8| 3| 3| 7| 2| 6| 5| 4| 3| 2| 6| 1| 3| 3| 3| 7| 0| 6| 0| 5| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                            X        X                                    |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Parasite Metazoan                    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Edema                                |                                  3                                       |             
      Parasite Metazoan                    |                                     X  X                 X               |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  A  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Clear Cell Focus                     |                                                                          |             
      Hemorrhage                           |                                                          4               |             
      Hepatodiaphragmatic Nodule           |    X                    X                             X                  |             
      Hyperplasia, Reticulum Cell          |                                                                          |             
      Vacuolization Cytoplasmic            |          3              2                 2           2                 3|             
      Bile Duct, Hyperplasia               | 3  3                                                                     |             
      Hepatocyte, Degeneration, Cystic     |    4                                               4                     |             
      Hepatocyte, Hyperplasia              |                      4                                                   |             
      Hepatocyte, Necrosis                 |          2                             3                                 |             
      Serosa, Fibrosis                     |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +                    +        +           +                     |             
      Fat, Inflammation, Granulomatous     |                               2                                          |             
      Fat, Necrosis                        |                                        4           2                     |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                  +                                       |             
      Hyperplasia                          |                                  3                                       |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              | 2  2                             2  2                 3                 2|             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Edema                                |                                                                          |             
      Hyperplasia                          |                                        2        1                       3|             
      Inflammation, Suppurative            |                                        2                                 |             
      Ulcer                                |                   2                                      2              4|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
      Necrosis                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            |                                     +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       |                                        4     2  2     2                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  59                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 6| 4| 7| 6| 5| 6| 5| 4| 7| 5| 6| 5| 7| 7| 4| 6| 5| 4| 6| 4| 6| 6| 5|             
                             DAY ON TEST   | 3| 6| 3| 6| 3| 0| 8| 3| 4| 9| 3| 5| 3| 8| 3| 2| 4| 3| 8| 9| 5| 6| 6| 5| 7|             
                                           | 6| 4| 8| 3| 3| 7| 2| 6| 5| 4| 3| 2| 6| 1| 3| 3| 3| 7| 0| 6| 0| 5| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Mineralization                       |                                                                          |             
      Atrium, Thrombosis                   |          3     3                                                         |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Vacuolization Cytoplasmic            |                                           2                              |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    3        1                       4  3                          3  3   |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |    3                       4                    2                        |             
      Pars Distalis, Hyperplasia           |    2                                3  2                    2        2   |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |                                  3     2     1                    2      |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Peritoneum                              |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |                3                                                         |             
      Inflammation, Suppurative            | 4                                            2                 4     4   |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             
      Epithelium, Hyperplasia              |                                        2     1                           |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Necrosis                             |                                                                          |             
      Artery, Inflammation                 |                                                                   2      |             
      Germinal Epithelium, Atrophy         |          4     4                       3                                3|             
      Interstitial Cell, Hyperplasia       | 3     3                                1           2  1  1               |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Myelofibrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |                                                 +        +     +     +   |             
                                            __________________________________________________________________________|             
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Fibrosis                             |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  60                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 6| 4| 7| 6| 5| 6| 5| 4| 7| 5| 6| 5| 7| 7| 4| 6| 5| 4| 6| 4| 6| 6| 5|             
                             DAY ON TEST   | 3| 6| 3| 6| 3| 0| 8| 3| 4| 9| 3| 5| 3| 8| 3| 2| 4| 3| 8| 9| 5| 6| 6| 5| 7|             
                                           | 6| 4| 8| 3| 3| 7| 2| 6| 5| 4| 3| 2| 6| 1| 3| 3| 3| 7| 0| 6| 0| 5| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Hyperplasia, Lymphoid                |                                              3                           |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectasia                              |                                  4                                       |             
                                            __________________________________________________________________________|             
   Lymph Node, Mediastinal                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                3                                                         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |    3           3        3           4        3                       3   |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Necrosis                             |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Galactocele                          |       3                                   3                              |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Granulomatous          | 3                                      2                                 |             
      Inflammation, Suppurative            |                                                    2                     |             
      Ulcer                                |                3                    3                          4        3|             
      Epidermis, Cyst                      |                                                                   3      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Gliosis                              |                                                 2                        |             
      Hemorrhage                           |                            2                                4           2|             
      Ventricle, Hydrocephalus             |       3                 3                             2           3      |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                         +                                                |             
      Hemorrhage                           |                         4                                                |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                         X        X        X                       X      |             
      Inflammation, Suppurative            |                                  1                                       |             
      Epiglottis, Metaplasia, Squamous     |                                                                          |             
      Epithelium, Hyperplasia              |                      1                                                   |             
      Epithelium, Metaplasia, Squamous     |                2                    2                    2        3      |             
      Glands, Inflammation, Suppurative    |                      3                                2                  |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                         1                       2        3  2            |             
      Alveolar Epithelium, Hyperplasia     |                                                    4                 2   |             
      Alveolar Epithelium, Infiltration    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  61                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 6| 4| 7| 6| 5| 6| 5| 4| 7| 5| 6| 5| 7| 7| 4| 6| 5| 4| 6| 4| 6| 6| 5|             
                             DAY ON TEST   | 3| 6| 3| 6| 3| 0| 8| 3| 4| 9| 3| 5| 3| 8| 3| 2| 4| 3| 8| 9| 5| 6| 6| 5| 7|             
                                           | 6| 4| 8| 3| 3| 7| 2| 6| 5| 4| 3| 2| 6| 1| 3| 3| 3| 7| 0| 6| 0| 5| 0| 2| 6|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 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                 |                                                                          |             
                                           |                                                                          |             
          Cellular, Histiocyte             |                   3                 2                                3   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                1         |             
      Foreign Body                         | X                 X                       X     X                 X      |             
      Inflammation, Suppurative            | 2                 2  2                    1     1     2           3  3   |             
      Nasopharyngeal Duct, Inflammation,   |                                                                          |             
           Suppurative                     |                                                                          |             
      Nasopharyngeal Duct, Metaplasia,     |                                                                          |             
           Squamous                        |                                                                          |             
      Olfactory Epithelium, Degeneration   |    2  1  1  2  1  2  1  1  1  2  1     1  1  1     1  2  1  2     2  1  1|             
      Respiratory Epithelium, Hyperplasia  |                                           1     2                 2      |             
      Respiratory Epithelium, Metaplasia,  |                                                                          |             
           Squamous                        | 2  2  1  1  1  1  1  2     2  2  1     2  1     1  3  2  1  2     1  3  2|             
      Vomeronasal Organ, Dilatation        |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                                               +            |             
      Cataract                             |             4                                               4            |             
      Cornea, Lens, Mineralization         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Nephropathy, Chronic                 | 2  3  3  3  3  3  2  2  3  2  3  1  2     3  3  2  3  3  1  2  1  4  3  4|             
      Cortex, Necrosis                     |                                     4  3                                 |             
      Renal Tubule, Hyperplasia            |       4                                                                  |             
      Renal Tubule, Mineralization         |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  62                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 6| 4| 4| 7| 5| 6| 7| 7| 6| 6| 6| 7| 6| 6| 5| 4| 6| 7| 7| 6| 6| 6|            |
                             DAY ON TEST   | 3| 7| 3| 5| 4| 9| 3| 2| 1| 3| 3| 7| 3| 8| 3| 3| 5| 9| 6| 2| 2| 3| 4| 8| 7|            |
                                           | 3| 9| 3| 8| 1| 1| 3| 0| 5| 3| 3| 8| 8| 4| 3| 2| 2| 0| 8| 4| 0| 3| 5| 0| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Parasite Metazoan                    |                            X     X                                       |      4     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Parasite Metazoan                    |       X                    X                                             |      2     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  48        |
      Edema                                |                                                                          |      1  3.0|
      Parasite Metazoan                    |                                  X        X     X              X     X   |      8     |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Clear Cell Focus                     |                   X                                                      |      1     |
      Hemorrhage                           |                                                                          |      1  4.0|
      Hepatodiaphragmatic Nodule           |                      X                 X                                 |      5     |
      Hyperplasia, Reticulum Cell          |                                                       3                  |      1  3.0|
      Vacuolization Cytoplasmic            |                                     2                    3        4      |      8  2.6|
      Bile Duct, Hyperplasia               |                                  3                                       |      3  3.0|
      Hepatocyte, Degeneration, Cystic     |                               3           2                              |      4  3.3|
      Hepatocyte, Hyperplasia              |             4                                                            |      2  4.0|
      Hepatocyte, Necrosis                 |                                                                   3      |      3  2.7|
      Serosa, Fibrosis                     |                                                                   4      |      1  4.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |    +     +  +           +                 +                       +      |  10        |
      Fat, Inflammation, Granulomatous     |                                                                          |      1  2.0|
      Fat, Necrosis                        |          3  4           4                 2                       4      |      7  3.3|
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                  +                                       |   2        |
      Hyperplasia                          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                            3                                             |      7  2.3|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Edema                                |    3                                         2                           |      2  2.5|
      Hyperplasia                          |                                        4     2           2        3      |      7  2.4|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Ulcer                                |                                                                   4      |      4  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                                                       3                  |      1  3.0|
      Necrosis                             |                                                                   4      |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR 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  63                                                               
NTP Experiment-Test: 60968-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 17:03:02  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 6| 4| 4| 7| 5| 6| 7| 7| 6| 6| 6| 7| 6| 6| 5| 4| 6| 7| 7| 6| 6| 6|            |
                             DAY ON TEST   | 3| 7| 3| 5| 4| 9| 3| 2| 1| 3| 3| 7| 3| 8| 3| 3| 5| 9| 6| 2| 2| 3| 4| 8| 7|            |
                                           | 3| 9| 3| 8| 1| 1| 3| 0| 5| 3| 3| 8| 8| 4| 3| 2| 2| 0| 8| 4| 0| 3| 5| 0| 9|      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   FISCHER 344 RATS 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|            |
 __________________________________________________________________________________________________________________________________ 
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  38        |
      Mineralization                       |                                                       4                  |      1  4.0|
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cardiomyopathy                       | 2                                   2                                2  2|      8  2.3|
      Mineralization                       |                                                       3                  |      1  3.0|
      Atrium, Thrombosis                   |                               3                                          |      3  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Vacuolization Cytoplasmic            |                                           2                          3   |      3  2.3|
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 3  3  3                 4           4           3        2           4   |     14  3.1|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                            3                                             |      1  3.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia                          |                                                       3  3  2            |      3  2.7|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                   3                             2     4  3               |      7  3.0|
      Pars Distalis, Hyperplasia           |    3                                                                     |      6  2.3|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  |             1                                                            |      5  1.8|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Peritoneum                              |                   +                                                      |   1        |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |