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TDMS Study 05133-04 Pathology Tables


                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                            ACETONITRILE


NTP Experiment-Test: 05133-04                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05




       Facility:  Battelle Northwest

       Chemical CAS #:  75-05-8

       Lock Date:  07/17/92

       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: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          60           60           60           60                                     
  Scheduled Sacrifice                                 10           10           10           10                                     
  Early Deaths                                                                                                                      
    Natural Death                                      6            5            8            5                                     
    Moribund Sacrifice                                15           12           13           13                                     
    Accidently Killed                                  1                                                                            
  Survivors                                                                                                                         
    Natural Death                                                   1                                                               
    Terminal Sacrifice                                28           32           29           32                                     
  Animals Examined Microscopically                    60           60           60           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (52)         (55)         (51)         (56)                                   
      Hyperplasia                                                                1 (2%)                                             
      Inflammation, Suppurative                                     2 (4%)       1 (2%)       1 (2%)                                
   Intestine Large, Colon                             (56)         (55)         (57)         (58)                                   
      Hemorrhage                                       1 (2%)                                                                       
      Necrosis                                         1 (2%)                                                                       
   Intestine Large, Cecum                             (55)         (56)         (58)         (56)                                   
      Hemorrhage                                       1 (2%)                                                                       
      Necrosis                                         1 (2%)                                                                       
   Intestine Small, Duodenum                          (52)         (54)         (54)         (55)                                   
      Inflammation, Suppurative                                                  1 (2%)                                             
   Intestine Small, Jejunum                           (54)         (56)         (56)         (57)                                   
      Peyer's Patch, Hyperplasia                       1 (2%)                                                                       
   Intestine Small, Ileum                             (55)         (57)         (55)         (57)                                   
      Amyloid Deposition                                                         1 (2%)                                             
   Liver                                              (59)         (60)         (60)         (59)                                   
      Angiectasis                                                                1 (2%)                                             
      Basophilic Focus                                 2 (3%)       3 (5%)                                                          
      Clear Cell Focus                                              1 (2%)       1 (2%)                                             
      Cyst                                                          1 (2%)                                                          
      Cytomegaly                                                    1 (2%)                                                          
      Degeneration, Cystic                             1 (2%)                                                                       
      Degeneration, Fatty                                           2 (3%)       1 (2%)                                             
      Eosinophilic Focus                               5 (8%)       3 (5%)       3 (5%)       4 (7%)                                
      Focal Cellular Change                            1 (2%)                    2 (3%)                                             
      Hematopoietic Cell Proliferation                 8 (14%)      2 (3%)       1 (2%)       4 (7%)                                
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Infarct                                          1 (2%)                                 1 (2%)                                
      Infiltration Cellular, Mononuclear Cell                       2 (3%)                                                          
      Karyomegaly                                                   1 (2%)                    1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Mitotic Alteration                                                         2 (3%)       1 (2%)                                
      Mixed Cell Focus                                 4 (7%)       4 (7%)       1 (2%)                                             
      Necrosis                                         5 (8%)       4 (7%)       8 (13%)      2 (3%)                                
      Pigmentation, Hemosiderin                                     1 (2%)                                                          
      Regeneration                                                  1 (2%)                                                          
      Bile Duct, Cyst                                  1 (2%)                                 1 (2%)                                
      Bile Duct, Degeneration                          1 (2%)                                                                       
      Centrilobular, Necrosis                          1 (2%)                    1 (2%)       3 (5%)                                
      Serosa, Inflammation, Suppurative                2 (3%)                                                                       
   Mesentery                                          (10)         (16)         (7)          (5)                                    
      Angiectasis                                      1 (10%)                                                                      
      Inflammation, Chronic                            2 (20%)                                                                      
      Fat, Necrosis                                    7 (70%)      9 (56%)      3 (43%)      4 (80%)                               
   Pancreas                                           (59)         (59)         (60)         (58)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Atrophy                                          2 (3%)       2 (3%)       1 (2%)                                             
      Focal Cellular Change                            2 (3%)       1 (2%)       2 (3%)                                             
      Hyperplasia                                                   1 (2%)                    1 (2%)                                
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Inflammation, Chronic                            3 (5%)       1 (2%)       1 (2%)                                             
      Duct, Ectasia                                    3 (5%)                                                                       
      Duct, Inflammation, Chronic                      2 (3%)                                                                       
   Salivary Glands                                    (59)         (60)         (60)         (59)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Suppurative                                     1 (2%)                                                          
   Stomach, Forestomach                               (59)         (60)         (60)         (58)                                   
      Angiectasis                                      1 (2%)                                                                       
      Diverticulum                                                  1 (2%)                                                          
      Hyperkeratosis                                                                          5 (9%)                                
      Hyperplasia, Squamous                            2 (3%)       8 (13%)      9 (15%)     25 (43%)                               
      Inflammation, Suppurative                        1 (2%)       3 (5%)       4 (7%)       3 (5%)                                
      Necrosis                                                                   1 (2%)                                             
      Ulcer                                            1 (2%)       2 (3%)       2 (3%)       5 (9%)                                
      Epithelium, Hyperplasia                          1 (2%)                                                                       
   Stomach, Glandular                                 (59)         (58)         (60)         (58)                                   
      Hyperplasia                                                   2 (3%)                                                          
      Inflammation, Suppurative                        1 (2%)       1 (2%)                                                          
      Mineralization                                                1 (2%)                                                          
   Tooth                                                                                     (1)                                    
      Dysplasia                                                                               1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (52)         (53)         (55)         (55)                                   
      Mineralization                                                1 (2%)       1 (2%)                                             
      Thrombosis                                                    1 (2%)                                                          
   Heart                                              (59)         (60)         (59)         (60)                                   
      Angiectasis                                                                1 (2%)                                             
      Cardiomyopathy                                  16 (27%)     19 (32%)     23 (39%)     15 (25%)                               
      Hyperplasia, Atypical                            1 (2%)                    1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (59)         (59)         (60)         (59)                                   
      Cyst                                                          3 (5%)       1 (2%)       1 (2%)                                
      Hematopoietic Cell Proliferation                 2 (3%)       2 (3%)       1 (2%)                                             
      Hyperplasia                                      4 (7%)       2 (3%)                                                          
      Hypertrophy                                      3 (5%)       4 (7%)       7 (12%)      3 (5%)                                
      Capsule, Hyperplasia                             1 (2%)                                 1 (2%)                                
   Adrenal Medulla                                    (58)         (58)         (60)         (58)                                   
      Hyperplasia                                      2 (3%)       2 (3%)       3 (5%)       2 (3%)                                
   Islets, Pancreatic                                 (59)         (59)         (60)         (57)                                   
      Hyperplasia                                      2 (3%)       5 (8%)                    1 (2%)                                
   Pituitary Gland                                    (58)         (59)         (60)         (58)                                   
      Pars Distalis, Cyst                              4 (7%)       3 (5%)       1 (2%)       1 (2%)                                
      Pars Distalis, Hyperplasia                      19 (33%)     16 (27%)     24 (40%)     21 (36%)                               
      Pars Distalis, Inflammation, Chronic                                                    1 (2%)                                
      Pars Intermedia, Hyperplasia                                               1 (2%)                                             
   Thyroid Gland                                      (59)         (58)         (60)         (59)                                   
      Inflammation                                                                            1 (2%)                                
      Inflammation, Suppurative                                     1 (2%)                                                          
      Follicle, Cyst                                   1 (2%)       1 (2%)                    3 (5%)                                
      Follicular Cell, Hyperplasia                    12 (20%)      6 (10%)      9 (15%)      6 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (40)         (41)         (46)         (44)                                   
      Atrophy                                          1 (3%)                                                                       
   Ovary                                              (58)         (57)         (58)         (57)                                   
      Abscess                                          4 (7%)                                                                       
      Amyloid Deposition                               1 (2%)       1 (2%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Angiectasis                                      3 (5%)       1 (2%)       2 (3%)                                             
      Atrophy                                         17 (29%)     19 (33%)     20 (34%)     13 (23%)                               
      Cyst                                            19 (33%)     18 (32%)     18 (31%)     13 (23%)                               
      Mineralization                                   1 (2%)                                                                       
      Germinal Epithelium, Hyperplasia                                                        1 (2%)                                
      Interstitium, Hyperplasia                                                               1 (2%)                                
   Uterus                                             (59)         (59)         (60)         (59)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Angiectasis                                                                1 (2%)       2 (3%)                                
      Dilatation                                                    2 (3%)       1 (2%)                                             
      Hyperplasia, Cystic                             57 (97%)     53 (90%)     55 (92%)     52 (88%)                               
      Inflammation, Suppurative                        1 (2%)                    2 (3%)       1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
      Arteriole, Hypertrophy                                                                  1 (2%)                                
      Artery, Inflammation, Chronic                                              1 (2%)                                             
      Myometrium, Hyperplasia                                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (59)         (59)         (60)         (59)                                   
      Hyperplasia, Megakaryocyte                                                              1 (2%)                                
      Hyperplasia, Neutrophil                          6 (10%)      1 (2%)       3 (5%)       3 (5%)                                
   Lymph Node                                         (7)          (9)          (9)          (1)                                    
      Axillary, Hyperplasia                                                      1 (11%)                                            
      Iliac, Hemorrhage                                             1 (11%)                                                         
      Iliac, Hyperplasia                               2 (29%)      1 (11%)      1 (11%)                                            
      Popliteal, Hyperplasia                                                     1 (11%)                                            
      Renal, Angiectasis                                                         1 (11%)                                            
      Renal, Congestion                                             1 (11%)                                                         
   Lymph Node, Bronchial                              (48)         (54)         (51)         (46)                                   
      Erythrophagocytosis                                           1 (2%)                                                          
      Hematopoietic Cell Proliferation                 2 (4%)                                                                       
      Hyperplasia                                     11 (23%)      4 (7%)       7 (14%)      4 (9%)                                
   Lymph Node, Mandibular                             (42)         (45)         (52)         (41)                                   
      Hyperplasia                                      5 (12%)                   4 (8%)       5 (12%)                               
   Lymph Node, Mesenteric                             (54)         (53)         (57)         (51)                                   
      Amyloid Deposition                                                         1 (2%)                                             
      Angiectasis                                      1 (2%)       1 (2%)       2 (4%)                                             
      Congestion                                       2 (4%)       1 (2%)                                                          
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Hemorrhage                                                                 1 (2%)                                             
      Hyperplasia                                      3 (6%)       5 (9%)       9 (16%)      4 (8%)                                
      Hyperplasia, Histiocytic                         1 (2%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
   Lymph Node, Mediastinal                            (43)         (43)         (44)         (41)                                   
      Erythrophagocytosis                                           1 (2%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Hematopoietic Cell Proliferation                 2 (5%)       1 (2%)                                                          
      Hyperplasia                                      6 (14%)      1 (2%)      10 (23%)      5 (12%)                               
      Inflammation, Suppurative                        2 (5%)                                                                       
   Spleen                                             (59)         (59)         (60)         (58)                                   
      Amyloid Deposition                                                         1 (2%)       1 (2%)                                
      Congestion                                       1 (2%)                                                                       
      Fibrosis                                                      1 (2%)                                                          
      Hematopoietic Cell Proliferation                12 (20%)     12 (20%)     15 (25%)     11 (19%)                               
      Hemorrhage                                       1 (2%)                                                                       
      Hyperplasia, Lymphoid                           14 (24%)     15 (25%)     13 (22%)      5 (9%)                                
      Capsule, Fibrosis                                                          1 (2%)                                             
   Thymus                                             (54)         (58)         (56)         (51)                                   
      Angiectasis                                                   1 (2%)       2 (4%)       1 (2%)                                
      Atrophy                                          5 (9%)       2 (3%)       1 (2%)       5 (10%)                               
      Developmental Malformation                                    1 (2%)                                                          
      Hyperplasia, Lymphoid                            6 (11%)      5 (9%)      12 (21%)      8 (16%)                               
      Necrosis                                                      1 (2%)                    1 (2%)                                
      Epithelial Cell, Hyperplasia                                               2 (4%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (59)         (57)         (60)         (57)                                   
      Hyperplasia                                      1 (2%)       2 (4%)       2 (3%)       1 (2%)                                
   Skin                                               (59)         (60)         (60)         (59)                                   
      Inflammation, Suppurative                                     1 (2%)                    2 (3%)                                
      Sebaceous Gland, Hyperplasia                                               1 (2%)                                             
      Subcutaneous Tissue, Inflammation, Chronic       1 (2%)                    1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (59)         (60)         (60)         (60)                                   
      Fibrous Osteodystrophy                          27 (46%)     18 (30%)     16 (27%)     19 (32%)                               
      Fracture                                                                   1 (2%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
   Skeletal Muscle                                                 (1)          (1)          (1)                                    
      Hemorrhage                                                                 1 (100%)     1 (100%)                              
      Inflammation                                                  1 (100%)     1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (59)         (60)         (60)         (59)                                   
      Hemorrhage                                                                              1 (2%)                                
      Inflammation                                     1 (2%)                                                                       
      Inflammation, Chronic                            1 (2%)       1 (2%)                    3 (5%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NERVOUS SYSTEM - CONT                                                                                                               
      Mineralization                                  28 (47%)     31 (52%)     28 (47%)     20 (34%)                               
      Necrosis                                         1 (2%)                                                                       
      Pigmentation, Hemosiderin                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (59)         (60)         (60)         (59)                                   
      Embolus                                                       1 (2%)                                                          
      Hemorrhage                                       4 (7%)       1 (2%)       5 (8%)       4 (7%)                                
      Infiltration Cellular, Mononuclear Cell                       1 (2%)                                                          
      Inflammation, Acute                              1 (2%)                                 1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                                                                       
      Thrombosis                                       1 (2%)                                 2 (3%)                                
      Alveolar Epithelium, Hyperplasia                 3 (5%)       4 (7%)       2 (3%)       1 (2%)                                
      Alveolus, Infiltration Cellular, Histiocyte      1 (2%)       3 (5%)       2 (3%)       1 (2%)                                
      Arteriole, Inflammation                                                    2 (3%)                                             
      Artery, Mediastinum, Inflammation                1 (2%)                                                                       
      Mediastinum, Hemorrhage                          1 (2%)                                                                       
      Mediastinum, Inflammation, Suppurative           1 (2%)                                                                       
      Perivascular, Infiltration Cellular,                                                                                          
          Mononuclear Cell                             2 (3%)                    3 (5%)       1 (2%)                                
   Nose                                               (59)         (60)         (60)         (59)                                   
      Inflammation, Suppurative                        1 (2%)                    2 (3%)                                             
      Nasolacrimal Duct, Inflammation, Suppurative     1 (2%)       2 (3%)                    1 (2%)                                
      Olfactory Epithelium, Atrophy                    5 (8%)       4 (7%)       5 (8%)       2 (3%)                                
      Olfactory Epithelium, Metaplasia                 4 (7%)       3 (5%)       2 (3%)       1 (2%)                                
      Olfactory Epithelium, Necrosis                                1 (2%)                    1 (2%)                                
      Respiratory Epithelium, Hyperplasia                                        1 (2%)                                             
      Respiratory Epithelium, Metaplasia, Squamous                               1 (2%)                                             
      Respiratory Epithelium, Necrosis                              1 (2%)       1 (2%)                                             
   Trachea                                            (59)         (59)         (59)         (59)                                   
      Metaplasia, Squamous                                                       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (59)         (59)         (60)         (58)                                   
      Amyloid Deposition                               1 (2%)       2 (3%)                                                          
      Hydronephrosis                                                1 (2%)                                                          
      Hyperplasia, Atypical                            1 (2%)                                                                       
      Infarct                                                       1 (2%)                                                          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Infiltration Cellular, Mononuclear Cell                       1 (2%)                                                          
      Inflammation, Suppurative                        1 (2%)                                                                       
      Metaplasia, Osseous                                           3 (5%)       1 (2%)       3 (5%)                                
      Nephropathy                                     24 (41%)     32 (54%)     27 (45%)     25 (43%)                               
      Arteriole, Inflammation, Chronic                 1 (2%)                                                                       
      Cortex, Cyst                                     1 (2%)                                                                       
      Cortex, Pigmentation, Hemosiderin                1 (2%)       1 (2%)                                                          
      Glomerulus, Embolus                                           1 (2%)                                                          
      Renal Tubule, Mineralization                                  1 (2%)                                                          
      Renal Tubule, Necrosis                                                                  2 (3%)                                
   Urinary Bladder                                    (57)         (57)         (59)         (57)                                   
      Inflammation, Chronic                            1 (2%)                    2 (3%)                                             
      Ulcer                                            1 (2%)                                                                       
      Arteriole, Inflammation                          1 (2%)                                                                       
      Transitional Epithelium, Hyperplasia             1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          60           60           60           60                                     
  Scheduled Sacrifice                                 10           10           10           10                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                13           14           16            6                                     
    Natural Death                                      5            4            2            1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                32           32           32           43                                     
  Animals Examined Microscopically                    60           60           60           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (54)         (56)         (55)         (55)                                   
      Cyst                                                          1 (2%)                                                          
      Degeneration                                     2 (4%)       1 (2%)       1 (2%)                                             
      Hyperplasia                                      1 (2%)                                                                       
      Inflammation, Suppurative                                     3 (5%)       1 (2%)       3 (5%)                                
   Intestine Large, Cecum                             (57)         (59)         (58)         (58)                                   
      Necrosis                                         1 (2%)                                                                       
   Intestine Small, Duodenum                          (56)         (58)         (58)         (58)                                   
      Peyer's Patch, Hyperplasia                                                 1 (2%)                                             
   Intestine Small, Jejunum                           (55)         (58)         (57)         (59)                                   
      Peyer's Patch, Hyperplasia                       1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
   Intestine Small, Ileum                             (56)         (59)         (58)         (59)                                   
      Peyer's Patch, Hyperplasia                                    1 (2%)                    1 (2%)                                
   Liver                                              (60)         (60)         (59)         (60)                                   
      Angiectasis                                                   1 (2%)       1 (2%)       1 (2%)                                
      Basophilic Focus                                 1 (2%)       2 (3%)       5 (8%)       1 (2%)                                
      Clear Cell Focus                                 4 (7%)       1 (2%)       2 (3%)       3 (5%)                                
      Cytomegaly                                       1 (2%)                                                                       
      Degeneration, Fatty                              5 (8%)       9 (15%)     12 (20%)      4 (7%)                                
      Eosinophilic Focus                               5 (8%)       5 (8%)       5 (8%)       4 (7%)                                
      Focal Cellular Change                            1 (2%)                                 1 (2%)                                
      Hematopoietic Cell Proliferation                 2 (3%)       3 (5%)       4 (7%)       2 (3%)                                
      Hemorrhage                                       1 (2%)       1 (2%)                                                          
      Infarct                                          2 (3%)       2 (3%)       2 (3%)       1 (2%)                                
      Karyomegaly                                      4 (7%)       3 (5%)       2 (3%)       3 (5%)                                
      Mitotic Alteration                               1 (2%)       3 (5%)                                                          
      Mixed Cell Focus                                 2 (3%)       6 (10%)      3 (5%)       3 (5%)                                
      Necrosis                                         5 (8%)       4 (7%)       1 (2%)       1 (2%)                                
      Vacuolization Cytoplasmic                                                  1 (2%)                                             
      Bile Duct, Cyst                                               3 (5%)                    1 (2%)                                
      Bile Duct, Degeneration                          1 (2%)                                                                       
      Bile Duct, Hyperplasia                           1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Centrilobular, Necrosis                          2 (3%)       2 (3%)                                                          
      Kupffer Cell, Pigmentation                                                 1 (2%)                                             
   Mesentery                                          (3)          (3)          (3)          (3)                                    
      Angiectasis                                                   1 (33%)                                                         
      Inflammation, Chronic                                         1 (33%)                                                         
      Fat, Necrosis                                    2 (67%)      1 (33%)      2 (67%)      2 (67%)                               
   Pancreas                                           (59)         (60)         (58)         (60)                                   
      Atrophy                                          1 (2%)       1 (2%)       3 (5%)                                             
      Focal Cellular Change                            3 (5%)       2 (3%)                    1 (2%)                                
      Inflammation, Chronic                                                      2 (3%)                                             
      Duct, Ectasia                                                              1 (2%)                                             
   Salivary Glands                                    (60)         (60)         (58)         (60)                                   
      Cyst                                                                                    1 (2%)                                
      Inflammation, Chronic                                         1 (2%)                                                          
      Inflammation, Suppurative                                     1 (2%)                                                          
   Stomach, Forestomach                               (59)         (60)         (58)         (60)                                   
      Hyperkeratosis                                   1 (2%)                    3 (5%)       2 (3%)                                
      Hyperplasia, Squamous                            3 (5%)       5 (8%)       6 (10%)     15 (25%)                               
      Inflammation, Suppurative                        2 (3%)       1 (2%)       4 (7%)       2 (3%)                                
      Ulcer                                            1 (2%)       1 (2%)       1 (2%)       2 (3%)                                
   Stomach, Glandular                                 (59)         (60)         (58)         (60)                                   
      Degeneration                                                               1 (2%)       1 (2%)                                
      Ectopic Tissue                                                                          1 (2%)                                
      Erosion                                          2 (3%)                                 1 (2%)                                
      Hyperplasia                                                                1 (2%)       2 (3%)                                
      Inflammation, Suppurative                        1 (2%)                    1 (2%)                                             
      Pigmentation, Hemosiderin                        2 (3%)       1 (2%)                    1 (2%)                                
   Tooth                                              (3)                                    (1)                                    
      Dysplasia                                        2 (67%)                                                                      
      Inflammation                                     1 (33%)                                1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (60)         (60)         (59)         (60)                                   
      Angiectasis                                                                             1 (2%)                                
      Cardiomyopathy                                  40 (67%)     42 (70%)     46 (78%)     44 (73%)                               
      Necrosis                                         1 (2%)                                 1 (2%)                                
      Arteriole, Inflammation, Chronic                 2 (3%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (58)         (60)         (58)         (60)                                   
      Accessory Adrenal Cortical Nodule                             1 (2%)       1 (2%)       1 (2%)                                
      Cyst                                                          1 (2%)       1 (2%)                                             
      Hyperplasia                                      7 (12%)     11 (18%)     13 (22%)     12 (20%)                               
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Hypertrophy                                     28 (48%)     36 (60%)     23 (40%)     37 (62%)                               
      Capsule, Hyperplasia                             1 (2%)                                                                       
   Adrenal Medulla                                    (59)         (60)         (57)         (60)                                   
      Hyperplasia                                      2 (3%)                    1 (2%)       1 (2%)                                
   Islets, Pancreatic                                 (57)         (60)         (58)         (60)                                   
      Hyperplasia                                      6 (11%)      7 (12%)      9 (16%)      4 (7%)                                
   Parathyroid Gland                                  (46)         (44)         (49)         (35)                                   
      Hyperplasia                                      1 (2%)                                                                       
   Pituitary Gland                                    (56)         (58)         (56)         (59)                                   
      Pars Distalis, Cyst                              4 (7%)       2 (3%)       1 (2%)       3 (5%)                                
      Pars Distalis, Hyperplasia                       1 (2%)       3 (5%)       2 (4%)                                             
   Thyroid Gland                                      (59)         (60)         (58)         (60)                                   
      Follicle, Cyst                                                1 (2%)       2 (3%)                                             
      Follicular Cell, Hyperplasia                     7 (12%)      5 (8%)       2 (3%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (60)         (60)         (58)         (60)                                   
      Granuloma Sperm                                                            1 (2%)       2 (3%)                                
      Hyperplasia                                                                1 (2%)                                             
      Inflammation, Chronic Active                                                            1 (2%)                                
      Inflammation, Suppurative                                                               1 (2%)                                
   Preputial Gland                                    (59)         (60)         (56)         (60)                                   
      Atrophy                                          2 (3%)                                 1 (2%)                                
      Ectasia                                          4 (7%)      12 (20%)      4 (7%)       2 (3%)                                
      Inflammation, Chronic Active                    14 (24%)     16 (27%)      9 (16%)     20 (33%)                               
   Prostate                                           (54)         (53)         (52)         (54)                                   
      Inflammation, Suppurative                        1 (2%)       1 (2%)       1 (2%)       2 (4%)                                
   Seminal Vesicle                                    (59)         (60)         (57)         (60)                                   
      Inflammation, Chronic Active                     1 (2%)       1 (2%)       1 (2%)                                             
      Inflammation, Suppurative                                     1 (2%)                    1 (2%)                                
   Testes                                             (60)         (60)         (59)         (60)                                   
      Atrophy                                          3 (5%)       1 (2%)       1 (2%)       2 (3%)                                
      Mineralization                                                1 (2%)                                                          
      Interstitial Cell, Hyperplasia                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (59)         (60)         (58)         (60)                                   
      Angiectasis                                      1 (2%)                                 1 (2%)                                
      Fibrosis                                         2 (3%)                                                                       
      Hyperplasia, Megakaryocyte                                    1 (2%)                                                          
      Hyperplasia, Neutrophil                          5 (8%)       7 (12%)      9 (16%)     11 (18%)                               
      Thrombosis                                       1 (2%)                                                                       
   Lymph Node                                         (3)          (2)          (2)                                                 
      Iliac, Hyperplasia                                            1 (50%)                                                         
      Pancreatic, Hyperplasia                                                    1 (50%)                                            
      Renal, Hyperplasia                                                         1 (50%)                                            
   Lymph Node, Bronchial                              (41)         (44)         (45)         (50)                                   
      Hyperplasia                                      1 (2%)       2 (5%)                                                          
   Lymph Node, Mandibular                             (43)         (39)         (36)         (44)                                   
      Hyperplasia                                      2 (5%)       3 (8%)       1 (3%)       2 (5%)                                
   Lymph Node, Mesenteric                             (56)         (59)         (57)         (58)                                   
      Angiectasis                                      1 (2%)                                                                       
      Congestion                                                    2 (3%)       5 (9%)       1 (2%)                                
      Hematopoietic Cell Proliferation                 2 (4%)                    3 (5%)                                             
      Hyperplasia                                      5 (9%)      10 (17%)      8 (14%)      3 (5%)                                
   Lymph Node, Mediastinal                            (47)         (45)         (44)         (40)                                   
      Hyperplasia                                      2 (4%)       2 (4%)       1 (2%)                                             
   Spleen                                             (59)         (60)         (58)         (60)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Angiectasis                                                                             1 (2%)                                
      Hematopoietic Cell Proliferation                12 (20%)     15 (25%)     16 (28%)     13 (22%)                               
      Hyperplasia, Lymphoid                            4 (7%)       2 (3%)       4 (7%)       8 (13%)                               
      Hyperplasia, Mononuclear Cell                                                           1 (2%)                                
   Thymus                                             (53)         (54)         (48)         (57)                                   
      Atrophy                                          4 (8%)       2 (4%)       1 (2%)       1 (2%)                                
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)                                                          
      Necrosis                                         1 (2%)                                                                       
      Epithelial Cell, Hyperplasia                                  1 (2%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (60)         (59)         (59)         (60)                                   
      Cyst Epithelial Inclusion                                                               1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                                 2 (3%)                                
      Pinna, Granuloma                                 1 (2%)                                                                       
      Subcutaneous Tissue, Inflammation, Chronic       6 (10%)      8 (14%)     10 (17%)     10 (17%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (60)         (60)         (59)         (60)                                   
      Fibrous Osteodystrophy                                                     1 (2%)                                             
      Inflammation, Suppurative                        1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (60)         (60)         (58)         (60)                                   
      Mineralization                                  23 (38%)     26 (43%)     16 (28%)     20 (33%)                               
      Thrombosis                                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (59)         (60)         (58)         (60)                                   
      Inflammation, Suppurative                        1 (2%)                                                                       
   Lung                                               (60)         (60)         (58)         (60)                                   
      Hemorrhage                                       5 (8%)       4 (7%)       1 (2%)       1 (2%)                                
      Inflammation, Chronic, Focal                                                            1 (2%)                                
      Inflammation, Granulomatous                                                             1 (2%)                                
      Alveolar Epithelium, Hyperplasia                 4 (7%)       5 (8%)       3 (5%)       4 (7%)                                
      Perivascular, Infiltration Cellular,                                                                                          
          Mononuclear Cell                                                                    1 (2%)                                
   Nose                                               (60)         (60)         (58)         (60)                                   
      Exudate                                          1 (2%)                                                                       
      Inflammation, Suppurative                        3 (5%)       2 (3%)       3 (5%)       2 (3%)                                
      Nasolacrimal Duct, Inflammation, Suppurative     4 (7%)       2 (3%)                                                          
      Olfactory Epithelium, Atrophy                    4 (7%)       1 (2%)       2 (3%)       1 (2%)                                
      Olfactory Epithelium, Metaplasia                 3 (5%)       1 (2%)       2 (3%)       1 (2%)                                
      Respiratory Epithelium, Hyperplasia                                                     1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous     1 (2%)                                                                       
   Trachea                                            (59)         (60)         (58)         (60)                                   
      Metaplasia, Squamous                                                       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (59)         (60)         (58)         (60)                                   
      Amyloid Deposition                               1 (2%)                                                                       
      Hydronephrosis                                   3 (5%)       5 (8%)       4 (7%)       6 (10%)                               
      Hyperplasia, Cystic                              2 (3%)       1 (2%)                    2 (3%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05133-04         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                            ACETONITRILE                                       Date: 05/20/95  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 06:55:05  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          CONTROL      50 PPM       100 PPM      200 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Inflammation, Suppurative                        1 (2%)       3 (5%)       3 (5%)       2 (3%)                                
      Metaplasia, Osseous                                           1 (2%)       1 (2%)                                             
      Nephropathy                                     41 (69%)     41 (68%)     39 (67%)     43 (72%)                               
      Arteriole, Inflammation, Chronic                 1 (2%)                                                                       
      Cortex, Cyst                                     5 (8%)       2 (3%)       3 (5%)       1 (2%)                                
      Renal Tubule, Hyperplasia                                                  1 (2%)                                             
      Renal Tubule, Mineralization                     1 (2%)                                                                       
   Urinary Bladder                                    (59)         (58)         (59)         (60)                                   
      Dilatation                                                    2 (3%)       2 (3%)       3 (5%)                                
      Hemorrhage                                                    1 (2%)                                                          
      Inflammation, Chronic                            1 (2%)       1 (2%)       3 (5%)       1 (2%)                                
      Inflammation, Suppurative                                     2 (3%)                    1 (2%)                                
      Pigmentation, Melanin                                         1 (2%)                                                          
      Ulcer                                                         1 (2%)       1 (2%)       1 (2%)                                
      Transitional Epithelium, Hyperplasia                          2 (3%)       1 (2%)       2 (3%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
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                             ----------              END OF REPORT             ----------                                           
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