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TDMS Study 97006-02 Pathology Tables

NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58

                                                          FINAL#1 MICE




       Facility:  Battelle Northwest

       Chemical CAS #:  108-10-1

       Lock Date:  01/24/03

       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: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                10            9            6            9                                     
    Natural Death                                      5            3            5            3                                     
    Accidently Killed                                               1                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           37           39           38                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (48)         (48)         (49)         (49)                                   
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
   Intestine Large, Rectum                            (47)         (48)         (48)         (49)                                   
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
   Intestine Large, Cecum                             (46)         (48)         (47)         (49)                                   
      Artery, Inflammation, Chronic Active             1 (2%)       1 (2%)                                                          
   Intestine Small, Duodenum                          (47)         (48)         (47)         (48)                                   
      Ulcer                                                         1 (2%)                                                          
      Peyer's Patch, Hyperplasia                                                              1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Basophilic Focus                                 3 (6%)       2 (4%)       1 (2%)       3 (6%)                                
      Clear Cell Focus                                 3 (6%)       4 (8%)       5 (10%)      2 (4%)                                
      Cyst                                                          1 (2%)                                                          
      Eosinophilic Focus                               4 (8%)      11 (22%)     10 (20%)     14 (28%)                               
      Fatty Change                                                               1 (2%)                                             
      Hematopoietic Cell Proliferation                                           2 (4%)                                             
      Infarct                                                       1 (2%)                                                          
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
      Inflammation, Chronic                                         1 (2%)                    2 (4%)                                
      Mixed Cell Focus                                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Necrosis                                         3 (6%)       1 (2%)       5 (10%)      1 (2%)                                
      Tension Lipidosis                                1 (2%)       2 (4%)       3 (6%)                                             
      Thrombosis                                       1 (2%)                                                                       
      Bile Duct, Hyperplasia                           1 (2%)                                                                       
   Mesentery                                          (11)         (11)         (13)         (8)                                    
      Artery, Inflammation, Chronic Active                          1 (9%)                                                          
      Fat, Hemorrhage                                  1 (9%)                                                                       
      Fat, Necrosis                                    9 (82%)      9 (82%)     11 (85%)      7 (88%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
   Pancreas                                           (50)         (50)         (49)         (50)                                   
      Atrophy                                          3 (6%)                    1 (2%)                                             
      Basophilic Focus                                                           1 (2%)                                             
      Inflammation, Chronic Active                     1 (2%)                    1 (2%)                                             
      Necrosis, Fatty                                                            1 (2%)                                             
      Artery, Inflammation, Chronic Active                          1 (2%)                                                          
      Duct, Cyst                                       1 (2%)                    1 (2%)                                             
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                                                                 1 (2%)                                
      Artery, Inflammation, Chronic Active                          1 (2%)                                                          
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Hyperplasia, Squamous                            1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
      Inflammation                                                  1 (2%)                    2 (4%)                                
      Artery, Inflammation, Chronic Active             2 (4%)                                                                       
   Stomach, Glandular                                 (49)         (50)         (48)         (49)                                   
      Metaplasia, Hepatocyte                                                     1 (2%)                                             
      Necrosis                                                                                1 (2%)                                
      Artery, Inflammation, Chronic Active             2 (4%)                                                                       
   Tooth                                              (1)                                    (1)                                    
      Malformation                                     1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                   3 (6%)       6 (12%)      5 (10%)      3 (6%)                                
      Inflammation, Suppurative                                                               1 (2%)                                
      Artery, Inflammation, Chronic Active             1 (2%)       2 (4%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Hematopoietic Cell Proliferation                                           1 (2%)                                             
      Hyperplasia                                      4 (8%)       3 (6%)       1 (2%)       2 (4%)                                
      Hypertrophy                                      3 (6%)                    3 (6%)       3 (6%)                                
      Infiltration Cellular, Mononuclear Cell                                                 1 (2%)                                
      Necrosis                                                      1 (2%)                                                          
   Adrenal Medulla                                    (50)         (50)         (49)         (49)                                   
      Hyperplasia                                      2 (4%)       2 (4%)       1 (2%)                                             
   Islets, Pancreatic                                 (50)         (50)         (49)         (50)                                   
      Hyperplasia                                                                2 (4%)       1 (2%)                                
   Pituitary Gland                                    (50)         (49)         (48)         (49)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Distalis, Angiectasis                       1 (2%)       3 (6%)       3 (6%)       2 (4%)                                
      Pars Distalis, Hyperplasia                      10 (20%)      8 (16%)     13 (27%)     11 (22%)                               
      Pars Intermedia, Hyperplasia                     1 (2%)                                                                       
   Thyroid Gland                                      (50)         (50)         (49)         (48)                                   
      Cyst                                                          1 (2%)                                                          
      Follicular Cell, Hyperplasia                     7 (14%)      5 (10%)     11 (22%)      8 (17%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                      (2)          (1)                                                 
      Inflammation, Suppurative                                                  1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (49)         (50)         (48)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Cyst                                            14 (29%)     13 (26%)     13 (27%)      9 (18%)                               
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                       1 (2%)                                                                       
      Artery, Inflammation, Chronic Active             1 (2%)                                 1 (2%)                                
   Uterus                                             (50)         (50)         (49)         (50)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Angiectasis                                      1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
      Hyperplasia, Cystic                                           1 (2%)                                                          
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Inflammation, Suppurative                                     1 (2%)       1 (2%)       1 (2%)                                
      Metaplasia, Squamous                                                                    1 (2%)                                
      Necrosis                                                      1 (2%)                                                          
      Thrombosis                                                                 1 (2%)                                             
      Endometrium, Hyperplasia, Cystic                49 (98%)     48 (96%)     46 (94%)     49 (98%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (49)         (50)                                   
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
   Lymph Node                                         (7)          (3)          (9)          (5)                                    
      Iliac, Ectasia                                                1 (33%)                                                         
      Iliac, Infiltration Cellular, Plasma Cell        1 (14%)                                                                      
      Lumbar, Angiectasis                                           1 (33%)                                                         
      Lumbar, Ectasia                                                            1 (11%)                                            
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Lumbar, Infiltration Cellular, Plasma Cell                                              1 (20%)                               
      Renal, Angiectasis                                            1 (33%)      1 (11%)                                            
      Renal, Ectasia                                   1 (14%)                                                                      
      Renal, Infiltration Cellular, Plasma Cell                                               1 (20%)                               
      Renal, Artery, Inflammation, Chronic Active                   1 (33%)                                                         
   Lymph Node, Mandibular                             (40)         (42)         (39)         (38)                                   
      Hyperplasia, Lymphoid                                         2 (5%)                                                          
      Infiltration Cellular, Plasma Cell                                                      1 (3%)                                
   Lymph Node, Mesenteric                             (50)         (49)         (49)         (47)                                   
      Angiectasis                                                                             1 (2%)                                
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
   Lymph Node, Mediastinal                            (46)         (40)         (38)         (41)                                   
      Hyperplasia, Lymphoid                                         1 (3%)                                                          
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
   Spleen                                             (50)         (50)         (49)         (50)                                   
      Hematopoietic Cell Proliferation                 5 (10%)      1 (2%)       7 (14%)      5 (10%)                               
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)         (50)         (49)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Skin                                               (50)         (50)         (50)         (50)                                   
      Foreign Body                                                  1 (2%)                                                          
      Hemorrhage                                       1 (2%)                                                                       
      Inflammation, Chronic Active                     2 (4%)       2 (4%)       5 (10%)      2 (4%)                                
      Inflammation, Suppurative                                     1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fracture                                                      1 (2%)                                                          
      Hyperostosis                                                               1 (2%)                                             
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
   Skeletal Muscle                                    (1)          (2)          (3)          (2)                                    
      Inflammation, Suppurative                                     1 (50%)                                                         
      Artery, Inflammation, Chronic Active                                                    1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NERVOUS SYSTEM - CONT                                                                                                               
   Brain                                              (50)         (50)         (50)         (50)                                   
      Meninges, Infiltration Cellular, Mononuclear                                                                                  
        Cell                                                        1 (2%)       2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (49)         (50)                                   
      Artery, Inflammation, Chronic Active             1 (2%)                    1 (2%)                                             
      Respiratory Epithelium, Degeneration, Hyaline                              1 (2%)                                             
   Lung                                               (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mononuclear Cell                                    1 (2%)                                             
      Alveolar Epithelium, Hyperplasia                 1 (2%)       5 (10%)      3 (6%)       5 (10%)                               
      Alveolus, Infiltration Cellular, Histiocyte      1 (2%)                    2 (4%)                                             
      Artery, Mineralization                                        1 (2%)                                                          
      Bronchiole, Hyperplasia                                       4 (8%)       2 (4%)                                             
   Nose                                               (50)         (50)         (50)         (49)                                   
      Infiltration Cellular, Mast Cell                 1 (2%)                                                                       
      Inflammation, Suppurative                        4 (8%)       3 (6%)       2 (4%)                                             
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
      Glands, Hyperplasia                             23 (46%)     30 (60%)     23 (46%)     20 (41%)                               
      Olfactory Epithelium, Atrophy                                 1 (2%)       1 (2%)                                             
      Olfactory Epithelium, Degeneration, Hyaline      8 (16%)      5 (10%)      4 (8%)       1 (2%)                                
      Respiratory Epithelium, Degeneration, Hyaline   24 (48%)     19 (38%)     20 (40%)     13 (27%)                               
      Respiratory Epithelium, Metaplasia               3 (6%)       3 (6%)       6 (12%)      1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous                               1 (2%)                                             
      Turbinate, Necrosis                                                        2 (4%)                                             
   Trachea                                            (50)         (50)         (49)         (50)                                   
      Degeneration, Hyaline                                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (49)         (48)         (49)         (50)                                   
      Cataract                                                                   1 (2%)                                             
      Degeneration                                                                            1 (2%)                                
      Cornea, Inflammation, Chronic Active             1 (2%)       1 (2%)       3 (6%)       2 (4%)                                
      Cornea, Mineralization                           1 (2%)                                                                       
      Retina, Atrophy                                  1 (2%)                                                                       
   Harderian Gland                                    (49)         (49)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (50)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Cyst                                                                       1 (2%)                                             
      Metaplasia, Osseous                              2 (4%)       2 (4%)       3 (6%)       2 (4%)                                
      Nephropathy                                     22 (44%)     28 (56%)     26 (53%)     27 (54%)                               
      Artery, Inflammation, Chronic Active                                       1 (2%)                                             
      Papilla, Necrosis                                1 (2%)                                 1 (2%)                                
      Pelvis, Dilatation                                                         1 (2%)                                             
      Renal Tubule, Hyperplasia                                                               1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (49)         (50)                                   
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 9            6           12            9                                     
    Natural Death                                      1            2            3            4                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                40           42           34           37                                     
    Natural Death                                                                1                                                  
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (43)         (44)         (39)         (45)                                   
      Infiltration Cellular, Polymorphonuclear                      1 (2%)                                                          
   Intestine Large, Rectum                            (50)         (48)         (49)         (49)                                   
      Hemorrhage                                                                 1 (2%)                                             
      Inflammation, Acute                              1 (2%)                                                                       
   Intestine Large, Cecum                             (49)         (48)         (47)         (47)                                   
      Hemorrhage                                                                 1 (2%)                                             
   Intestine Small, Duodenum                          (49)         (48)         (45)         (47)                                   
      Ulcer                                            1 (2%)                                                                       
   Intestine Small, Jejunum                           (49)         (48)         (47)         (47)                                   
      Cyst                                                                                    1 (2%)                                
      Peyer's Patch, Hyperplasia                       1 (2%)       1 (2%)       2 (4%)                                             
   Intestine Small, Ileum                             (49)         (48)         (48)         (47)                                   
      Inflammation, Acute                                                                     1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                                 1 (2%)                                
      Basophilic Focus                                 8 (16%)      5 (10%)      4 (8%)       8 (16%)                               
      Clear Cell Focus                                22 (44%)     13 (26%)     13 (26%)     20 (40%)                               
      Eosinophilic Focus                               3 (6%)       4 (8%)       5 (10%)      8 (16%)                               
      Hepatodiaphragmatic Nodule                                                 1 (2%)                                             
      Infarct                                                       1 (2%)                                                          
      Inflammation, Chronic                                                                   1 (2%)                                
      Inflammation, Granulomatous                      1 (2%)                    1 (2%)                                             
      Mixed Cell Focus                                 1 (2%)                    1 (2%)       1 (2%)                                
      Necrosis                                         5 (10%)      1 (2%)       2 (4%)       7 (14%)                               
      Tension Lipidosis                                4 (8%)       3 (6%)       3 (6%)       1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
      Bile Duct, Cyst                                               1 (2%)                                                          
      Bile Duct, Hyperplasia                           1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatocyte, Erythrophagocytosis                                                         1 (2%)                                
      Hepatocyte, Vacuolization Cytoplasmic            1 (2%)                    2 (4%)       1 (2%)                                
   Mesentery                                          (9)          (3)          (3)          (4)                                    
      Fat, Necrosis                                    9 (100%)     3 (100%)     3 (100%)     3 (75%)                               
   Salivary Glands                                    (50)         (50)         (48)         (50)                                   
      Inflammation, Acute                              1 (2%)                                                                       
   Stomach, Forestomach                               (50)         (49)         (49)         (50)                                   
      Hyperplasia, Squamous                            3 (6%)       3 (6%)       2 (4%)       1 (2%)                                
      Inflammation                                     1 (2%)       2 (4%)       3 (6%)                                             
      Ulcer                                            2 (4%)       1 (2%)                    2 (4%)                                
   Stomach, Glandular                                 (49)         (49)         (49)         (49)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Necrosis                                         1 (2%)                    1 (2%)                                             
   Tooth                                                                        (1)                                                 
      Malformation                                                               1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  10 (20%)      8 (16%)      2 (4%)      10 (20%)                               
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                       2 (4%)                    3 (6%)       1 (2%)                                
      Artery, Inflammation, Chronic Active             2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (49)         (50)                                   
      Hyperplasia                                     13 (26%)     18 (36%)     13 (27%)      9 (18%)                               
      Hypertrophy                                     26 (52%)     30 (60%)     26 (53%)     14 (28%)                               
   Adrenal Medulla                                    (50)         (50)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       3 (6%)                                             
   Islets, Pancreatic                                 (49)         (50)         (49)         (50)                                   
      Hyperplasia                                      1 (2%)       2 (4%)                    1 (2%)                                
   Pituitary Gland                                    (50)         (47)         (48)         (49)                                   
      Pars Distalis, Hyperplasia                       1 (2%)                    2 (4%)                                             
   Thyroid Gland                                      (50)         (49)         (50)         (50)                                   
      Follicular Cell, Hyperplasia                     4 (8%)       4 (8%)       6 (12%)      8 (16%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  2 (4%)                    2 (4%)       1 (2%)                                
      Infiltration Cellular, Polymorphonuclear                      1 (2%)                                                          
      Inflammation, Granulomatous                                   1 (2%)                                                          
   Penis                                              (1)          (1)                       (1)                                    
      Inflammation, Acute                                           1 (100%)                  1 (100%)                              
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Ectasia                                          2 (4%)       3 (6%)                    1 (2%)                                
      Inflammation, Chronic Active                                  1 (2%)                    2 (4%)                                
   Prostate                                           (50)         (49)         (49)         (50)                                   
      Inflammation, Suppurative                        1 (2%)       1 (2%)                                                          
   Seminal Vesicle                                    (50)         (50)         (49)         (50)                                   
      Dilatation                                       1 (2%)                                                                       
      Inflammation, Chronic Active                     1 (2%)       1 (2%)                    1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Atrophy                                          2 (4%)       2 (4%)       3 (6%)       1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
      Interstitial Cell, Hyperplasia                   1 (2%)                    1 (2%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Lymph Node, Bronchial                              (39)         (35)         (37)         (39)                                   
      Hyperplasia, Lymphoid                                                      1 (3%)                                             
   Lymph Node, Mandibular                             (37)         (36)         (32)         (34)                                   
      Hyperplasia, Lymphoid                                                      1 (3%)                                             
   Lymph Node, Mesenteric                             (49)         (48)         (48)         (48)                                   
      Infiltration Cellular, Histiocyte                                                       1 (2%)                                
   Lymph Node, Mediastinal                            (42)         (38)         (36)         (38)                                   
      Hyperplasia, Lymphoid                                                      1 (3%)                                             
   Spleen                                             (50)         (50)         (49)         (49)                                   
      Hematopoietic Cell Proliferation                 2 (4%)       1 (2%)       1 (2%)       3 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (49)         (50)                                   
      Inflammation, Acute                              1 (2%)                                                                       
      Inflammation, Chronic Active                                  2 (4%)       1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Atrophy                                                                    1 (2%)                                             
      Hyperostosis                                     1 (2%)                                                                       
      Joint, Cartilage, Hyperplasia                    1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Hydrocephalus                                                              1 (2%)                                             
      Necrosis                                         2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion, Chronic                              1 (2%)                                                                       
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia                                                   1 (2%)                                                          
      Inflammation, Chronic Active                                               1 (2%)                                             
      Pigmentation                                                               1 (2%)                                             
      Thrombosis                                                                 1 (2%)                                             
      Alveolar Epithelium, Hyperplasia                 7 (14%)      5 (10%)      5 (10%)      2 (4%)                                
      Alveolus, Infiltration Cellular, Histiocyte      1 (2%)       1 (2%)       3 (6%)                                             
      Bronchiole, Hyperplasia                          1 (2%)       2 (4%)       3 (6%)       2 (4%)                                
   Nose                                               (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)                                                                       
      Inflammation, Suppurative                        4 (8%)       1 (2%)       3 (6%)       2 (4%)                                
      Glands, Hyperplasia                             33 (66%)     32 (64%)     24 (48%)     26 (52%)                               
      Olfactory Epithelium, Atrophy                                              1 (2%)                                             
      Olfactory Epithelium, Degeneration, Hyaline      1 (2%)       1 (2%)       2 (4%)                                             
      Olfactory Epithelium, Necrosis                                             1 (2%)                                             
      Respiratory Epithelium, Degeneration, Hyaline                 1 (2%)       3 (6%)                                             
      Respiratory Epithelium, Hyperplasia                                        1 (2%)                                             
      Respiratory Epithelium, Metaplasia               9 (18%)     11 (22%)     13 (26%)      6 (12%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (49)         (48)         (49)         (49)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 97006-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                       METHYL ISOBUTYL KETONE                                  Date: 04/29/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 07:39:58    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      450 PPM      900 PPM      1800 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Cataract                                                                                1 (2%)                                
      Degeneration                                                               1 (2%)       1 (2%)                                
      Cornea, Inflammation, Acute                                   1 (2%)                                                          
      Cornea, Inflammation, Chronic Active                          2 (4%)                                                          
      Cornea, Mineralization                                                                  1 (2%)                                
      Retina, Atrophy                                  1 (2%)                                                                       
   Harderian Gland                                    (50)         (49)         (50)         (50)                                   
      Hyperplasia                                      3 (6%)       4 (8%)       1 (2%)       2 (4%)                                
      Hypertrophy                                      1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (50)                                   
      Cyst                                                                       1 (2%)                                             
      Inflammation, Suppurative                        1 (2%)       1 (2%)       1 (2%)       3 (6%)                                
      Metaplasia, Osseous                              2 (4%)       2 (4%)       3 (6%)       1 (2%)                                
      Nephropathy                                     41 (82%)     45 (90%)     40 (82%)     43 (86%)                               
      Renal Tubule, Hyperplasia                        2 (4%)       2 (4%)       1 (2%)                                             
   Urinary Bladder                                    (50)         (49)         (49)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Inflammation, Suppurative                                     1 (2%)                                                          
                                                                                                                                    
                                                                                                                                    
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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