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TDMS Study 60968-01 Pathology Tables

NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28

                                                           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


































a  Number of animals examined microscopically at site and number of animals with lesion

                                                              Page   1

NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                17           22           22           13                                     
    Natural Death                                      6            3            4            5                                     
    Accidently Killed                                               1                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                27           24           24           31                                     
    Natural Death                                                                             1                                     
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (49)         (50)         (50)         (50)                                   
      Periesophageal Tissue, Inflammation, Chronic                                                                                  
          Active                                       1 (2%)                                                                       
   Intestine Large, Colon                             (48)         (47)         (49)         (47)                                   
      Diverticulum                                     1 (2%)                                                                       
      Parasite Metazoan                                3 (6%)       2 (4%)       3 (6%)       2 (4%)                                
   Intestine Large, Rectum                            (48)         (47)         (49)         (47)                                   
      Parasite Metazoan                                6 (13%)      2 (4%)       3 (6%)       4 (9%)                                
   Intestine Large, Cecum                             (48)         (47)         (49)         (45)                                   
      Diverticulum                                                               1 (2%)                                             
      Parasite Metazoan                                4 (8%)                    1 (2%)                                             
   Intestine Small, Ileum                             (47)         (47)         (49)         (45)                                   
      Parasite Metazoan                                             1 (2%)                                                          
   Liver                                              (49)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)       1 (2%)                                                          
      Basophilic Focus                                 2 (4%)                    3 (6%)                                             
      Basophilic Focus, Multiple                       3 (6%)                                                                       
      Clear Cell Focus                                 4 (8%)       5 (10%)      3 (6%)       3 (6%)                                
      Clear Cell Focus, Multiple                       5 (10%)      1 (2%)       3 (6%)       2 (4%)                                
      Eosinophilic Focus                                            1 (2%)                    1 (2%)                                
      Hepatodiaphragmatic Nodule                       6 (12%)      6 (12%)      7 (14%)      5 (10%)                               
      Inflammation, Granulomatous                      2 (4%)                                                                       
      Vacuolization Cytoplasmic                        5 (10%)      2 (4%)       2 (4%)       7 (14%)                               
      Hepatocyte, Hyperplasia                          1 (2%)                                                                       
      Hepatocyte, Necrosis                                                                    1 (2%)                                
      Serosa, Hemorrhage                               1 (2%)                                                                       
   Mesentery                                          (7)          (7)          (8)          (4)                                    
      Artery, Inflammation, Chronic                                 1 (14%)                                                         
      Fat, Necrosis                                    5 (71%)      4 (57%)      6 (75%)      4 (100%)                              
   Oral Mucosa                                        (4)                       (2)          (3)                                    
      Fibrosis                                         1 (25%)                                                                      
      Hyperplasia                                      1 (25%)                                                                      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Chronic                            1 (25%)                                                                      
      Inflammation, Suppurative                                                  1 (50%)                                            
      Gingival, Inflammation, Suppurative                                        1 (50%)                                            
      Pharyngeal, Hyperplasia                          2 (50%)                   1 (50%)      2 (67%)                               
   Pancreas                                           (49)         (49)         (49)         (50)                                   
      Atrophy                                          3 (6%)       2 (4%)       3 (6%)                                             
      Artery, Inflammation, Chronic                                 1 (2%)                                                          
   Stomach, Forestomach                               (49)         (49)         (50)         (50)                                   
      Hyperkeratosis                                   1 (2%)                                                                       
      Hyperplasia                                      5 (10%)      2 (4%)       5 (10%)      5 (10%)                               
      Inflammation, Suppurative                        1 (2%)                    1 (2%)                                             
      Ulcer                                            1 (2%)       2 (4%)       5 (10%)      2 (4%)                                
   Tongue                                             (1)                       (1)          (2)                                    
      Epithelium, Hyperplasia                          1 (100%)                               1 (50%)                               
   Tooth                                              (1)          (1)          (2)                                                 
      Developmental Malformation                       1 (100%)                  1 (50%)                                            
      Inflammation, Suppurative                                     1 (100%)     1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   1 (2%)                                 2 (4%)                                
      Atrium, Thrombosis                               2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (49)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Vacuolization Cytoplasmic                       12 (24%)      5 (10%)      9 (18%)     11 (22%)                               
   Adrenal Medulla                                    (49)         (49)         (47)         (49)                                   
      Hyperplasia                                      4 (8%)       2 (4%)                                                          
   Islets, Pancreatic                                 (50)         (48)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)                                                          
   Pituitary Gland                                    (48)         (50)         (49)         (50)                                   
      Cyst                                             6 (13%)     14 (28%)     13 (27%)     11 (22%)                               
      Hemorrhage                                                    2 (4%)       2 (4%)                                             
      Pars Distalis, Hyperplasia                       9 (19%)      6 (12%)      6 (12%)      5 (10%)                               
      Pars Distalis, Hypertrophy                                                 1 (2%)                                             
   Thyroid Gland                                      (49)         (49)         (50)         (50)                                   
      C-Cell, Hyperplasia                              8 (16%)      7 (14%)      9 (18%)      6 (12%)                               
      Follicular Cell, Hyperplasia                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (48)         (50)         (50)         (48)                                   
      Cyst                                             7 (15%)     11 (22%)     14 (28%)      9 (19%)                               
      Hyperplasia                                      2 (4%)       4 (8%)       1 (2%)       1 (2%)                                
      Inflammation, Suppurative                        2 (4%)       1 (2%)       1 (2%)       3 (6%)                                
   Ovary                                              (49)         (50)         (50)         (50)                                   
      Cyst                                                          1 (2%)       3 (6%)       2 (4%)                                
   Uterus                                             (48)         (50)         (50)         (50)                                   
      Cyst                                                          1 (2%)       1 (2%)                                             
      Cervix, Hypertrophy                                                        1 (2%)                                             
      Endometrium, Cyst                                                                       1 (2%)                                
      Endometrium, Hyperplasia                         1 (2%)       1 (2%)       2 (4%)                                             
      Endometrium, Metaplasia, Squamous                                          1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Lymph Node                                         (4)          (4)          (4)          (5)                                    
      Renal, Pigmentation                                                        1 (25%)                                            
   Lymph Node, Mandibular                             (45)         (50)         (46)         (46)                                   
      Angiectasis                                                   1 (2%)                                                          
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)                                             
   Lymph Node, Mesenteric                             (49)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Hemorrhage                                       1 (2%)                    2 (4%)                                             
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
   Lymph Node, Mediastinal                            (48)         (49)         (50)         (50)                                   
      Fibrosis                                                      1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Spleen                                             (49)         (49)         (49)         (50)                                   
      Accessory Spleen                                 4 (8%)       1 (2%)       2 (4%)                                             
      Angiectasis                                                   1 (2%)                                                          
      Fibrosis                                         2 (4%)       2 (4%)       1 (2%)       4 (8%)                                
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Hemorrhage                                       1 (2%)       2 (4%)                    2 (4%)                                
   Thymus                                             (48)         (50)         (50)         (50)                                   
      Cyst                                                          1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Galactocele                                      1 (2%)                    3 (6%)       1 (2%)                                
      Inflammation, Chronic                            1 (2%)                                                                       
      Epithelium, Hyperplasia                                       1 (2%)                                                          
   Skin                                               (49)         (50)         (50)         (50)                                   
      Hyperkeratosis                                   1 (2%)       4 (8%)       1 (2%)                                             
      Hyperplasia                                      1 (2%)                                                                       
      Inflammation, Granulomatous                      1 (2%)                                                                       
      Inflammation, Suppurative                                     1 (2%)                    1 (2%)                                
      Ulcer                                            1 (2%)       3 (6%)       1 (2%)                                             
      Epidermis, Cyst                                               2 (4%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (49)         (50)         (50)         (50)                                   
      Hyperostosis                                                                            1 (2%)                                
      Cranium, Fracture                                             1 (2%)                                                          
      Cranium, Femur, Osteopetrosis                                 1 (2%)                                                          
      Maxilla, Fracture                                             1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (49)         (49)         (50)         (50)                                   
      Gliosis                                                       1 (2%)                                                          
      Hemorrhage                                       4 (8%)       2 (4%)       5 (10%)      1 (2%)                                
      Necrosis                                                      1 (2%)                                                          
      Ventricle, Hydrocephalus                         5 (10%)      3 (6%)       3 (6%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (49)         (50)         (48)         (50)                                   
      Foreign Body                                     6 (12%)      2 (4%)       7 (15%)      4 (8%)                                
      Inflammation, Suppurative                                     1 (2%)       3 (6%)       6 (12%)                               
      Epiglottis, Metaplasia, Squamous                 2 (4%)                    4 (8%)       6 (12%)                               
      Epithelium, Hyperplasia                          5 (10%)      1 (2%)                    1 (2%)                                
      Epithelium, Metaplasia, Squamous                 5 (10%)      1 (2%)       6 (13%)     10 (20%)                               
      Glands, Inflammation, Suppurative                5 (10%)     11 (22%)      4 (8%)       8 (16%)                               
   Lung                                               (49)         (50)         (50)         (50)                                   
      Hemorrhage                                       3 (6%)                    4 (8%)       4 (8%)                                
      Inflammation, Granulomatous                      1 (2%)                                                                       
      Alveolar Epithelium, Fibrosis                    4 (8%)       2 (4%)       2 (4%)       2 (4%)                                
      Alveolar Epithelium, Foreign Body                1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 1 (2%)       6 (12%)      3 (6%)       3 (6%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Alveolar Epithelium, Infiltration Cellular,                                                                                   
           Histiocyte                                 10 (20%)     10 (20%)     11 (22%)      7 (14%)                               
      Bronchiole, Hyperplasia                          1 (2%)                                                                       
   Nose                                               (49)         (50)         (49)         (50)                                   
      Cyst                                                          2 (4%)       5 (10%)                                            
      Foreign Body                                     2 (4%)       2 (4%)       5 (10%)      5 (10%)                               
      Hemorrhage                                                    1 (2%)                                                          
      Inflammation, Suppurative                        2 (4%)       3 (6%)       5 (10%)     11 (22%)                               
      Nasolacrimal Duct, Inflammation, Suppurative     1 (2%)                                 1 (2%)                                
      Nasolacrimal Duct, Metaplasia, Squamous          1 (2%)                                 1 (2%)                                
      Olfactory Epithelium, Degeneration                                         2 (4%)      45 (90%)                               
      Respiratory Epithelium, Hyperplasia              1 (2%)                    1 (2%)       1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous     1 (2%)      11 (22%)      9 (18%)     44 (88%)                               
   Pleura                                             (1)          (1)                                                              
      Inflammation                                     1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (3)          (2)          (1)          (1)                                    
      Cornea, Mineralization                                        1 (50%)                                                         
      Lens, Cataract                                   2 (67%)      1 (50%)      1 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (49)         (50)         (50)                                   
      Nephropathy, Chronic                            35 (71%)     30 (61%)     30 (60%)     36 (72%)                               
      Cortex, Necrosis                                                                        1 (2%)                                
      Medulla, Renal Tubule, Cyst                      1 (2%)                                                                       
      Pelvis, Dilatation                                                         1 (2%)       1 (2%)                                
      Renal Tubule, Degeneration                                                              1 (2%)                                
      Renal Tubule, Inflammation, Suppurative                                    1 (2%)       1 (2%)                                
      Renal Tubule, Mineralization                     5 (10%)      2 (4%)       5 (10%)      2 (4%)                                
   Urinary Bladder                                    (49)         (49)         (50)         (50)                                   
      Hemorrhage                                                                 1 (2%)       1 (2%)                                
      Transitional Epithelium, Hyperplasia             2 (4%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      3            3            5            5                                     
    Moribund Sacrifice                                35           32           34           35                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                12           15           11           10                                     
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (49)         (49)         (50)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
      Parasite Metazoan                                1 (2%)       2 (4%)       3 (6%)       4 (8%)                                
      Ulcer                                                                      1 (2%)                                             
   Intestine Large, Rectum                            (50)         (47)         (49)         (50)                                   
      Parasite Metazoan                                4 (8%)       3 (6%)       3 (6%)       2 (4%)                                
   Intestine Large, Cecum                             (47)         (49)         (48)         (48)                                   
      Edema                                                                                   1 (2%)                                
      Parasite Metazoan                                2 (4%)       1 (2%)       3 (6%)       8 (17%)                               
   Intestine Small, Ileum                             (48)         (49)         (48)         (47)                                   
      Diverticulum                                                               1 (2%)                                             
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Liver                                              (50)         (49)         (50)         (50)                                   
      Angiectasis                                      2 (4%)       6 (12%)      4 (8%)                                             
      Basophilic Focus                                              2 (4%)       1 (2%)                                             
      Clear Cell Focus                                 3 (6%)       2 (4%)                    1 (2%)                                
      Eosinophilic Focus                               1 (2%)                                                                       
      Hemorrhage                                                                              1 (2%)                                
      Hepatodiaphragmatic Nodule                       5 (10%)      4 (8%)       5 (10%)      5 (10%)                               
      Hyperplasia, Reticulum Cell                                                             1 (2%)                                
      Inflammation, Granulomatous                                                2 (4%)                                             
      Mixed Cell Focus                                                           1 (2%)                                             
      Thrombosis                                                                 1 (2%)                                             
      Vacuolization Cytoplasmic                       10 (20%)      6 (12%)      6 (12%)      8 (16%)                               
      Bile Duct, Hyperplasia                           4 (8%)       2 (4%)       3 (6%)       3 (6%)                                
      Hepatocyte, Degeneration, Cystic                 2 (4%)       5 (10%)      5 (10%)      4 (8%)                                
      Hepatocyte, Hyperplasia                          1 (2%)       2 (4%)       2 (4%)       2 (4%)                                
      Hepatocyte, Necrosis                             2 (4%)       2 (4%)       4 (8%)       3 (6%)                                
      Serosa, Fibrosis                                                                        1 (2%)                                
   Mesentery                                          (11)         (12)         (8)          (10)                                   
      Fat, Hemorrhage                                               1 (8%)                                                          
      Fat, Inflammation, Granulomatous                 1 (9%)       1 (8%)                    1 (10%)                               
      Fat, Necrosis                                   10 (91%)     10 (83%)      7 (88%)      7 (70%)                               
   Oral Mucosa                                                     (3)          (2)          (2)                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Cyst                                                          1 (33%)                                                         
      Hyperplasia                                                                             1 (50%)                               
      Gingival, Hyperplasia                                                      1 (50%)                                            
      Pharyngeal, Hyperplasia                                       1 (33%)      1 (50%)                                            
   Pancreas                                           (50)         (48)         (50)         (50)                                   
      Atrophy                                          9 (18%)      8 (17%)     11 (22%)      7 (14%)                               
   Stomach, Forestomach                               (50)         (49)         (50)         (50)                                   
      Edema                                            3 (6%)                                 2 (4%)                                
      Hyperkeratosis                                                             3 (6%)                                             
      Hyperplasia                                      5 (10%)      9 (18%)     15 (30%)      7 (14%)                               
      Inflammation, Suppurative                                     1 (2%)       2 (4%)       1 (2%)                                
      Necrosis                                                      1 (2%)                                                          
      Ulcer                                            4 (8%)       5 (10%)      9 (18%)      4 (8%)                                
   Stomach, Glandular                                 (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                                     1 (2%)                                                          
      Mineralization                                                                          1 (2%)                                
      Necrosis                                         2 (4%)                                 1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
      Ulcer                                                         1 (2%)       1 (2%)                                             
   Tooth                                                           (1)          (1)                                                 
      Developmental Malformation                                    1 (100%)                                                        
      Inflammation, Suppurative                                                  1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (41)         (48)         (50)         (38)                                   
      Mineralization                                                                          1 (3%)                                
   Heart                                              (50)         (49)         (50)         (50)                                   
      Cardiomyopathy                                   6 (12%)      1 (2%)       3 (6%)       8 (16%)                               
      Mineralization                                                                          1 (2%)                                
      Atrium, Thrombosis                               2 (4%)       2 (4%)       4 (8%)       3 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (50)                                   
      Hemorrhage                                       1 (2%)       1 (2%)                                                          
      Hyperplasia                                                   1 (2%)                                                          
      Vacuolization Cytoplasmic                        3 (6%)       6 (12%)      6 (12%)      3 (6%)                                
   Adrenal Medulla                                    (49)         (49)         (50)         (50)                                   
      Hyperplasia                                     20 (41%)     16 (33%)     12 (24%)     14 (28%)                               
   Islets, Pancreatic                                 (50)         (49)         (50)         (50)                                   
      Hyperplasia                                      2 (4%)       3 (6%)       1 (2%)       1 (2%)                                
   Parathyroid Gland                                  (48)         (48)         (49)         (48)                                   
      Hyperplasia                                      1 (2%)       1 (2%)                    3 (6%)                                
   Pituitary Gland                                    (50)         (49)         (49)         (50)                                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Cyst                                             3 (6%)       2 (4%)       2 (4%)       7 (14%)                               
      Hemorrhage                                       2 (4%)       4 (8%)       3 (6%)                                             
      Pars Distalis, Hyperplasia                       4 (8%)       9 (18%)      5 (10%)      6 (12%)                               
      Pars Distalis, Hypertrophy                                    1 (2%)                                                          
   Thyroid Gland                                      (50)         (49)         (50)         (50)                                   
      C-Cell, Hyperplasia                              3 (6%)       5 (10%)      8 (16%)      5 (10%)                               
      Follicular Cell, Hyperplasia                     1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (49)         (50)         (50)                                   
      Inflammation, Granulomatous                      2 (4%)                    1 (2%)                                             
      Inflammation, Suppurative                        1 (2%)                                                                       
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Penis                                                                        (1)                                                 
      Hemorrhage                                                                 1 (100%)                                           
      Thrombosis, Acute                                                          1 (100%)                                           
   Preputial Gland                                    (50)         (49)         (50)         (50)                                   
      Cyst                                             3 (6%)      10 (20%)     11 (22%)      1 (2%)                                
      Hyperplasia                                      4 (8%)       1 (2%)       2 (4%)       2 (4%)                                
      Inflammation, Chronic                            1 (2%)                    1 (2%)                                             
      Inflammation, Suppurative                        9 (18%)      3 (6%)       8 (16%)     10 (20%)                               
   Prostate                                           (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                        4 (8%)       4 (8%)       4 (8%)       2 (4%)                                
      Epithelium, Hyperplasia                          2 (4%)       3 (6%)       2 (4%)       3 (6%)                                
   Seminal Vesicle                                    (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                                     1 (2%)                                                          
      Epithelium, Hyperplasia                          1 (2%)       1 (2%)                                                          
   Testes                                             (50)         (50)         (50)         (50)                                   
      Necrosis                                                                                1 (2%)                                
      Artery, Inflammation                             3 (6%)                    1 (2%)       1 (2%)                                
      Germinal Epithelium, Atrophy                     7 (14%)      6 (12%)      8 (16%)      8 (16%)                               
      Interstitial Cell, Hyperplasia                   7 (14%)      1 (2%)       5 (10%)      8 (16%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (50)         (50)                                   
      Hyperplasia, Reticulum Cell                                                1 (2%)                                             
      Myelofibrosis                                                                           2 (4%)                                
   Lymph Node                                         (15)         (10)         (6)          (7)                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Iliac, Ectasia                                                1 (10%)                                                         
   Lymph Node, Bronchial                              (50)         (46)         (49)         (50)                                   
      Fibrosis                                                                   1 (2%)                                             
   Lymph Node, Mandibular                             (46)         (46)         (44)         (44)                                   
      Fibrosis                                                                                1 (2%)                                
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)                    1 (2%)                                
   Lymph Node, Mesenteric                             (50)         (49)         (50)         (50)                                   
      Ectasia                                                                                 1 (2%)                                
      Fibrosis                                                                   1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Lymph Node, Mediastinal                            (49)         (49)         (50)         (50)                                   
      Fibrosis                                                                   1 (2%)       2 (4%)                                
      Hemorrhage                                       1 (2%)       1 (2%)                                                          
      Hyperplasia, Histiocytic                                      1 (2%)                                                          
   Spleen                                             (50)         (49)         (50)         (50)                                   
      Accessory Spleen                                 1 (2%)       1 (2%)       1 (2%)                                             
      Angiectasis                                                   1 (2%)                                                          
      Fibrosis                                        10 (20%)     18 (37%)      9 (18%)     17 (34%)                               
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hemorrhage                                       3 (6%)       1 (2%)       1 (2%)       2 (4%)                                
      Necrosis                                                      1 (2%)       2 (4%)       1 (2%)                                
   Thymus                                             (50)         (49)         (50)         (49)                                   
      Ectopic Parathyroid Gland                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)         (50)         (50)                                   
      Galactocele                                      5 (10%)                   1 (2%)       3 (6%)                                
      Epithelium, Hyperplasia                                       1 (2%)       1 (2%)                                             
   Skin                                               (50)         (50)         (50)         (50)                                   
      Acanthosis                                                    1 (2%)                                                          
      Hyperkeratosis                                   2 (4%)      13 (26%)      2 (4%)                                             
      Hyperplasia                                                   5 (10%)                                                         
      Inflammation, Granulomatous                      2 (4%)                                 4 (8%)                                
      Inflammation, Suppurative                        3 (6%)                                 2 (4%)                                
      Ulcer                                            1 (2%)       1 (2%)       3 (6%)       5 (10%)                               
      Epidermis, Cyst                                  4 (8%)       1 (2%)       1 (2%)       3 (6%)                                
      Sebaceous Gland, Cyst                                                      1 (2%)                                             
      Sebaceous Gland, Hyperplasia                                  1 (2%)                                                          
      Subcutaneous Tissue, Edema                                                 1 (2%)                                             
      Subcutaneous Tissue, Hemorrhage                  1 (2%)                                                                       
      Subcutaneous Tissue, Epidermis, Cyst                                       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (48)         (50)         (50)                                   
      Cranium, Fibrosis                                             1 (2%)                                                          
      Cranium, Inflammation, Granulomatous                          2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Gliosis                                                                                 1 (2%)                                
      Hemorrhage                                       4 (8%)       9 (18%)      6 (12%)      4 (8%)                                
      Ventricle, Hydrocephalus                         3 (6%)       1 (2%)       8 (16%)      5 (10%)                               
   Spinal Cord                                                     (1)          (1)          (1)                                    
      Hemorrhage                                                                              1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (49)         (49)         (50)                                   
      Foreign Body                                     3 (6%)       4 (8%)       3 (6%)       5 (10%)                               
      Inflammation, Suppurative                                     1 (2%)                    2 (4%)                                
      Epiglottis, Metaplasia, Squamous                                                        1 (2%)                                
      Epithelium, Hyperplasia                          1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Epithelium, Metaplasia, Squamous                 1 (2%)       3 (6%)       1 (2%)       4 (8%)                                
      Glands, Inflammation, Suppurative                4 (8%)       6 (12%)      6 (12%)      3 (6%)                                
   Lung                                               (50)         (49)         (50)         (50)                                   
      Hemorrhage                                       7 (14%)      3 (6%)       8 (16%)      6 (12%)                               
      Inflammation, Granulomatous                                                1 (2%)                                             
      Alveolar Epithelium, Fibrosis                                 5 (10%)                                                         
      Alveolar Epithelium, Foreign Body                1 (2%)                    1 (2%)                                             
      Alveolar Epithelium, Hyperplasia                 5 (10%)      9 (18%)      4 (8%)       5 (10%)                               
      Alveolar Epithelium, Infiltration Cellular,                                                                                   
           Histiocyte                                  2 (4%)      10 (20%)      8 (16%)      6 (12%)                               
      Alveolar Epithelium, Pigmentation                                          1 (2%)                                             
      Bronchiole, Bronchus, Interstitium, Fibrosis                  1 (2%)                                                          
      Interstitium, Mineralization                                  1 (2%)                                                          
   Nose                                               (50)         (49)         (49)         (50)                                   
      Cyst                                             5 (10%)      3 (6%)       7 (14%)      7 (14%)                               
      Foreign Body                                     5 (10%)      5 (10%)      4 (8%)       7 (14%)                               
      Inflammation, Suppurative                        5 (10%)      3 (6%)       6 (12%)     15 (30%)                               
      Nasopharyngeal Duct, Hyperplasia                                           1 (2%)                                             
      Nasopharyngeal Duct, Inflammation,                                                                                            
          Suppurative                                                                         1 (2%)                                
      Nasopharyngeal Duct, Metaplasia, Squamous                                               2 (4%)                                
      Olfactory Epithelium, Degeneration                                         3 (6%)      44 (88%)                               
      Respiratory Epithelium, Hyperplasia              2 (4%)                    3 (6%)       5 (10%)                               
      Respiratory Epithelium, Metaplasia, Squamous     1 (2%)       1 (2%)      10 (20%)     44 (88%)                               
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 60968-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ISOBUTYRALDEHYDE                                     Date: 08/06/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 15:28:28  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      500 PPM      1000 PPM     2000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Vomeronasal Organ, Dilatation                                                           1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (4)          (1)          (5)          (3)                                    
      Cataract                                         3 (75%)                   2 (40%)      3 (100%)                              
      Cornea, Mineralization                           1 (25%)                                                                      
      Cornea, Lens, Mineralization                                                            1 (33%)                               
      Lens, Cataract                                                1 (100%)     1 (20%)                                            
      Lens, Mineralization                             1 (25%)                                                                      
   Harderian Gland                                                              (1)                                                 
      Hyperplasia                                                                1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (50)         (50)                                   
      Nephropathy, Chronic                            47 (94%)     48 (98%)     48 (96%)     49 (98%)                               
      Artery, Inflammation                                                       1 (2%)                                             
      Artery, Necrosis, Fibrinoid                                                1 (2%)                                             
      Cortex, Cyst                                                               1 (2%)                                             
      Cortex, Necrosis                                              1 (2%)                    2 (4%)                                
      Pelvis, Transitional Epithelium, Hyperplasia     1 (2%)                                                                       
      Renal Tubule, Hyperplasia                                     1 (2%)                    2 (4%)                                
      Renal Tubule, Hyperplasia, Atypical                                        1 (2%)                                             
      Renal Tubule, Mineralization                                                            1 (2%)                                
   Urinary Bladder                                    (50)         (48)         (50)         (50)                                   
      Calculus Micro Observation Only                  1 (2%)       1 (2%)       1 (2%)                                             
      Hemorrhage                                                                 2 (4%)       1 (2%)                                
      Inflammation, Suppurative                        1 (2%)       1 (2%)                                                          
      Ulcer                                                         1 (2%)                                                          
      Transitional Epithelium, Hyperplasia             4 (8%)       2 (4%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
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                             ----------              END OF REPORT             ----------                                           
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