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TDMS Study 05203-09 Pathology Tables

NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00
Route: DOSED FEED                                                                                                 Time: 09:50:01

                                                         MICE, FINAL#1




       Facility:  Southern Research Institute

       Chemical CAS #:  88-72-2

       Lock Date:  03/08/99

       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: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          60           60           60           60                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 4            6            7           22                                     
    Natural Death                                      4            8            6           33                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                52           46           47            5                                     
                                                                                                                                    
  Animals Examined Microscopically                    60           60           60           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (54)         (53)         (54)         (31)                                   
      Cyst                                             1 (2%)       1 (2%)                                                          
   Intestine Large, Cecum                             (56)         (53)         (54)         (32)                                   
      Edema                                                                      1 (2%)                                             
      Inflammation, Chronic                                                                   1 (3%)                                
   Intestine Small, Jejunum                           (56)         (53)         (56)         (34)                                   
      Peyer's Patch, Hyperplasia, Lymphoid             1 (2%)                    1 (2%)                                             
      Peyer's Patch, Inflammation, Chronic, Focal,                                                                                  
           Suppurative                                              1 (2%)                                                          
   Liver                                              (60)         (59)         (59)         (60)                                   
      Angiectasis                                                   1 (2%)                    3 (5%)                                
      Basophilic Focus                                 1 (2%)       6 (10%)      2 (3%)       6 (10%)                               
      Clear Cell Focus                                 1 (2%)                    2 (3%)       4 (7%)                                
      Congestion, Focal                                1 (2%)       2 (3%)       1 (2%)                                             
      Cyst                                                          1 (2%)                                                          
      Eosinophilic Focus                               2 (3%)       3 (5%)       6 (10%)     28 (47%)                               
      Hyperplasia, Focal, Lymphoid                     2 (3%)       5 (8%)       2 (3%)       1 (2%)                                
      Infiltration Cellular, Mixed Cell               45 (75%)     38 (64%)     37 (63%)     43 (72%)                               
      Inflammation, Focal                                                                     1 (2%)                                
      Mixed Cell Focus                                                           1 (2%)       3 (5%)                                
      Necrosis                                         3 (5%)                    2 (3%)      13 (22%)                               
      Tension Lipidosis                                1 (2%)       1 (2%)                                                          
      Bile Duct, Cyst                                               1 (2%)                                                          
      Hepatocyte, Fatty Change                                      1 (2%)                                                          
      Hepatocyte, Fatty Change, Diffuse                             2 (3%)                                                          
      Hepatocyte, Necrosis, Focal                                                             6 (10%)                               
      Hepatocyte, Tension Lipidosis                                                           1 (2%)                                
      Hepatocyte, Vacuolization Cytoplasmic,                                                                                        
          Diffuse                                                   2 (3%)                                                          
      Hepatocyte, Vacuolization Cytoplasmic, Focal     1 (2%)       2 (3%)       2 (3%)       9 (15%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatocyte, Periportal, Depletion Glycogen                                              1 (2%)                                
      Hepatocyte, Centrilobular, Fatty Change          2 (3%)                    2 (3%)                                             
      Hepatocyte, Centrilobular, Necrosis                                        1 (2%)                                             
      Oval Cell, Hyperplasia                                                                  4 (7%)                                
   Mesentery                                          (11)         (9)          (9)          (34)                                   
      Hemorrhage                                                                 1 (11%)                                            
      Inflammation, Chronic                            1 (9%)                                 2 (6%)                                
      Artery, Inflammation, Chronic                                              1 (11%)                                            
      Fat, Necrosis                                    6 (55%)      5 (56%)      4 (44%)                                            
   Pancreas                                           (60)         (57)         (58)         (57)                                   
      Acinus, Atrophy, Diffuse                                      2 (4%)       1 (2%)       1 (2%)                                
      Acinus, Atrophy, Focal                           1 (2%)                                 1 (2%)                                
      Duct, Cyst                                       2 (3%)       1 (2%)                                                          
      Duct, Inflammation, Chronic, Focal               2 (3%)                                                                       
   Stomach, Forestomach                               (60)         (58)         (58)         (59)                                   
      Diverticulum                                     1 (2%)                                                                       
      Edema                                                         1 (2%)                                                          
      Inflammation, Focal                              1 (2%)       2 (3%)       1 (2%)                                             
      Ulcer                                            1 (2%)       1 (2%)       1 (2%)                                             
      Epithelium, Hyperplasia                          1 (2%)       4 (7%)       6 (10%)      1 (2%)                                
   Stomach, Glandular                                 (58)         (57)         (57)         (52)                                   
      Erosion                                          1 (2%)                                                                       
      Inflammation, Focal                                                                     2 (4%)                                
      Ulcer                                                         1 (2%)       2 (4%)       1 (2%)                                
      Glands, Degeneration, Cystic, Focal                                        2 (4%)                                             
   Tooth                                              (8)          (4)                       (2)                                    
      Peridontal Tissue, Inflammation, Chronic         8 (100%)     4 (100%)                  2 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                                    (2)          (1)          (1)                                    
      Aorta, Mineralization                                         1 (50%)      1 (100%)                                           
   Heart                                              (60)         (60)         (59)         (58)                                   
      Angiectasis                                                                             1 (2%)                                
      Infiltration Cellular, Mixed Cell                             1 (2%)       1 (2%)                                             
      Inflammation, Chronic, Focal                                                            2 (3%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (59)         (59)         (58)         (60)                                   
      Accessory Adrenal Cortical Nodule                2 (3%)                    1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Cyst                                                                       2 (3%)                                             
      Cytoplasmic Alteration, Focal                                 1 (2%)                                                          
      Hyperplasia, Focal                                                                      1 (2%)                                
   Adrenal Medulla                                    (59)         (57)         (58)         (59)                                   
      Hyperplasia                                      2 (3%)                                                                       
   Islets, Pancreatic                                 (60)         (57)         (60)         (56)                                   
      Atrophy, Diffuse                                              1 (2%)                                                          
   Parathyroid Gland                                  (57)         (55)         (57)         (50)                                   
      Cyst                                             1 (2%)       1 (2%)                    1 (2%)                                
   Pituitary Gland                                    (58)         (58)         (53)         (53)                                   
      Pars Distalis, Cyst                                           1 (2%)                                                          
      Pars Distalis, Cytoplasmic Alteration, Focal     1 (2%)       4 (7%)       3 (6%)                                             
      Pars Distalis, Hyperplasia, Focal                1 (2%)       1 (2%)       2 (4%)                                             
   Thyroid Gland                                      (60)         (59)         (58)         (53)                                   
      Degeneration, Cystic, Focal                     14 (23%)     16 (27%)     16 (28%)     13 (25%)                               
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Inflammation, Chronic, Focal                     2 (3%)       1 (2%)                                                          
      Follicle, Cyst                                                1 (2%)                    2 (4%)                                
      Follicular Cell, Hyperplasia                     1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (1)                       (3)          (3)                                    
      Abdominal, Cyst                                                            1 (33%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (58)         (57)         (57)         (58)                                   
      Degeneration, Cystic                            11 (19%)      4 (7%)       5 (9%)       2 (3%)                                
      Inflammation, Chronic                            3 (5%)       2 (4%)                                                          
      Pigmentation                                     3 (5%)       2 (4%)                    1 (2%)                                
   Ovary                                              (59)         (56)         (56)         (56)                                   
      Angiectasis                                      3 (5%)       2 (4%)       1 (2%)                                             
      Cyst                                            11 (19%)     16 (29%)     12 (21%)     11 (20%)                               
      Cyst, Multiple                                   1 (2%)       2 (4%)       1 (2%)                                             
      Hemorrhage                                       1 (2%)       2 (4%)                    1 (2%)                                
      Hyperplasia, Tubular                                                       1 (2%)                                             
      Mineralization                                                             1 (2%)                                             
      Interstitial Cell, Hyperplasia                                             2 (4%)                                             
      Periovarian Tissue, Cyst                                      1 (2%)                                                          
      Periovarian Tissue, Inflammation, Chronic                                  1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Uterus                                             (60)         (59)         (60)         (59)                                   
      Angiectasis                                      1 (2%)                    2 (3%)       1 (2%)                                
      Angiectasis, Focal                                            1 (2%)                                                          
      Atrophy                                                                    1 (2%)                                             
      Congestion                                                    1 (2%)                                                          
      Cyst                                             1 (2%)       1 (2%)       3 (5%)                                             
      Hemorrhage                                                    1 (2%)       1 (2%)       1 (2%)                                
      Hydrometra                                      24 (40%)     24 (41%)     22 (37%)     15 (25%)                               
      Hyperplasia, Focal, Histiocytic                                            1 (2%)                                             
      Inflammation, Suppurative                        2 (3%)       1 (2%)       1 (2%)       2 (3%)                                
      Pigmentation, Focal                                                        1 (2%)                                             
      Endometrium, Hyperplasia, Cystic                54 (90%)     51 (86%)     53 (88%)     37 (63%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (60)         (58)         (60)         (60)                                   
      Hemorrhage, Focal                                                          1 (2%)                                             
      Hyperplasia                                      1 (2%)                    2 (3%)       2 (3%)                                
      Inflammation, Chronic, Focal                     1 (2%)                                                                       
      Myelofibrosis                                                 2 (3%)                                                          
      Myelofibrosis, Focal                             1 (2%)                                                                       
   Lymph Node                                         (6)          (3)          (10)         (11)                                   
      Iliac, Hematopoietic Cell Proliferation                                                 1 (9%)                                
      Iliac, Hemorrhage                                                          1 (10%)                                            
      Iliac, Hyperplasia                                                         1 (10%)                                            
      Iliac, Hyperplasia, Lymphoid                                               2 (20%)                                            
      Inguinal, Hyperplasia                                                                   1 (9%)                                
      Mediastinal, Hematopoietic Cell Proliferation                                           1 (9%)                                
      Mediastinal, Hemorrhage                                                                 3 (27%)                               
      Mediastinal, Hyperplasia                                                                1 (9%)                                
      Mediastinal, Hyperplasia, Lymphoid                                                      2 (18%)                               
      Pancreatic, Hyperplasia, Lymphoid                                          1 (10%)                                            
      Renal, Hemorrhage                                                          1 (10%)                                            
      Renal, Hyperplasia                                                         2 (20%)      1 (9%)                                
      Renal, Hyperplasia, Lymphoid                                               1 (10%)                                            
   Lymph Node, Mandibular                             (58)         (55)         (55)         (48)                                   
      Hyperplasia                                                                             1 (2%)                                
      Hyperplasia, Lymphoid                                         1 (2%)       1 (2%)       1 (2%)                                
   Lymph Node, Mesenteric                             (53)         (58)         (57)         (57)                                   
      Hemorrhage                                                                 1 (2%)       1 (2%)                                
      Hyperplasia                                      2 (4%)       1 (2%)       2 (4%)       4 (7%)                                
      Hyperplasia, Lymphoid                            6 (11%)      2 (3%)       2 (4%)       2 (4%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Hyperplasia, Mast Cell                           1 (2%)                                                                       
   Spleen                                             (59)         (57)         (58)         (57)                                   
      Congestion                                                                 2 (3%)                                             
      Depletion Cellular                                                                      1 (2%)                                
      Fibrosis                                         1 (2%)                                                                       
      Hematopoietic Cell Proliferation                11 (19%)     19 (33%)     21 (36%)     54 (95%)                               
      Hyperplasia, Lymphoid                            8 (14%)      5 (9%)       4 (7%)       2 (4%)                                
      Pigmentation, Focal                                                        1 (2%)                                             
   Thymus                                             (57)         (56)         (55)         (44)                                   
      Angiectasis                                      1 (2%)                    1 (2%)       1 (2%)                                
      Atrophy                                          1 (2%)                                 1 (2%)                                
      Cyst                                             1 (2%)                                                                       
      Hyperplasia, Lymphoid                            5 (9%)                    2 (4%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (60)         (59)         (60)         (59)                                   
      Ectasia                                          1 (2%)                    1 (2%)                                             
   Skin                                               (60)         (60)         (60)         (60)                                   
      Subcutaneous Tissue, Angiectasis, Focal                                    1 (2%)                                             
      Subcutaneous Tissue, Cyst                        1 (2%)                                                                       
      Subcutaneous Tissue, Edema                                    1 (2%)       2 (3%)       4 (7%)                                
      Subcutaneous Tissue, Hemorrhage, Focal           1 (2%)                                                                       
      Subcutaneous Tissue, Inflammation, Chronic,                                                                                   
           Focal                                       2 (3%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (60)         (60)         (60)         (60)                                   
      Callus                                                                     1 (2%)                                             
      Fibrous Osteodystrophy                                                                  1 (2%)                                
      Hyperostosis                                                                            2 (3%)                                
      Femur, Callus                                                                           1 (2%)                                
      Maxilla, Hyperostosis, Focal                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (60)         (60)         (59)         (58)                                   
      Atrophy, Focal                                   1 (2%)                    1 (2%)                                             
      Compression, Focal                                                         1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (60)         (60)         (59)         (57)                                   
      Congestion                                       1 (2%)       2 (3%)       1 (2%)       1 (2%)                                
      Edema, Focal                                                               1 (2%)                                             
      Hemorrhage                                       2 (3%)       1 (2%)       1 (2%)       2 (4%)                                
      Hyperplasia, Focal, Histiocytic                               2 (3%)                                                          
      Hyperplasia, Histiocytic                         1 (2%)                                                                       
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)       2 (3%)       1 (2%)                                
      Infiltration Cellular, Mixed Cell                                                       9 (16%)                               
      Metaplasia, Osseous                                           1 (2%)                                                          
      Alveolar Epithelium, Hyperplasia                              1 (2%)                                                          
      Artery, Mediastinum, Inflammation, Chronic                                              1 (2%)                                
      Bronchus, Glands, Cyst                                                                  1 (2%)                                
   Nose                                               (60)         (60)         (59)         (57)                                   
      Hemorrhage                                                                              1 (2%)                                
      Mucosa, Glands, Dilatation, Focal                                          3 (5%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (59)         (56)         (58)         (59)                                   
      Atrophy, Focal                                   2 (3%)                                                                       
      Congestion                                       2 (3%)       3 (5%)       3 (5%)       1 (2%)                                
      Cyst                                             2 (3%)                    2 (3%)       1 (2%)                                
      Hydronephrosis                                                             1 (2%)                                             
      Hyperplasia, Lymphoid                                         4 (7%)       1 (2%)                                             
      Infiltration Cellular, Mixed Cell                                          1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
      Mineralization, Focal                                                                   1 (2%)                                
      Nephropathy                                      9 (15%)     14 (25%)     10 (17%)     11 (19%)                               
      Pigmentation                                                                            1 (2%)                                
      Artery, Inflammation, Chronic                                                           1 (2%)                                
      Bilateral, Atrophy, Focal                                     1 (2%)                                                          
      Bilateral, Fibrosis, Focal                                    1 (2%)                                                          
      Bilateral, Inflammation, Chronic, Focal                       1 (2%)                                                          
      Pelvis, Dilatation                                            1 (2%)                    1 (2%)                                
      Pelvis, Hemorrhage                                                                      1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Renal Tubule, Accumulation, Hyaline Droplet      1 (2%)       3 (5%)       2 (3%)      10 (17%)                               
      Renal Tubule, Casts Protein                      6 (10%)      8 (14%)      7 (12%)      6 (10%)                               
      Renal Tubule, Dilatation                                                                1 (2%)                                
      Renal Tubule, Necrosis                                                     1 (2%)                                             
      Renal Tubule, Pigmentation                                    1 (2%)       3 (5%)      35 (59%)                               
      Renal Tubule, Vacuolization Cytoplasmic                                    1 (2%)                                             
   Urinary Bladder                                    (59)         (54)         (57)         (54)                                   
      Transitional Epithelium, Hyperplasia, Focal                                1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          60           60           60           60                                     
  Early Deaths                                                                                                                      
    Natural Death                                      5           21           39           29                                     
    Moribund Sacrifice                                 3            5           21           31                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                52           34                                                               
                                                                                                                                    
  Animals Examined Microscopically                    60           60           60           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (54)         (42)         (31)         (35)                                   
      Fibrosis                                                      1 (2%)                                                          
   Intestine Large, Cecum                             (56)         (49)         (36)         (44)                                   
      Epithelium, Degeneration, Mucoid                              1 (2%)                                                          
   Intestine Small, Jejunum                           (56)         (43)         (35)         (40)                                   
      Inflammation, Focal                                           1 (2%)                                                          
      Ulcer                                                         1 (2%)                                                          
      Epithelium, Degeneration, Cystic, Focal          1 (2%)                                                                       
      Epithelium, Hyperplasia, Focal, Adenomatous      1 (2%)                                                                       
      Peyer's Patch, Hyperplasia, Lymphoid                          1 (2%)                                                          
      Peyer's Patch, Inflammation, Chronic                          1 (2%)                                                          
   Liver                                              (60)         (59)         (57)         (60)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Angiectasis                                      1 (2%)                    2 (4%)       1 (2%)                                
      Basophilic Focus                                              6 (10%)      4 (7%)                                             
      Clear Cell Focus                                 3 (5%)       2 (3%)                                                          
      Congestion, Focal                                2 (3%)       1 (2%)                                                          
      Eosinophilic Focus                               3 (5%)      14 (24%)      1 (2%)       1 (2%)                                
      Fibrosis, Focal                                               1 (2%)       1 (2%)                                             
      Infiltration Cellular, Mixed Cell               46 (77%)     40 (68%)     24 (42%)     29 (48%)                               
      Inflammation, Chronic, Focal                                  1 (2%)       1 (2%)                                             
      Inflammation, Focal, Suppurative                              1 (2%)                                                          
      Mineralization, Focal                                         1 (2%)                                                          
      Mixed Cell Focus                                 2 (3%)                                                                       
      Necrosis                                         1 (2%)      15 (25%)     27 (47%)     30 (50%)                               
      Artery, Angiectasis                                                                     1 (2%)                                
      Artery, Inflammation, Chronic                                                           1 (2%)                                
      Hepatocyte, Fatty Change, Diffuse                2 (3%)                                                                       
      Hepatocyte, Necrosis, Focal                      2 (3%)                                                                       
      Hepatocyte, Syncytial Alteration, Focal         16 (27%)     26 (44%)     43 (75%)     39 (65%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatocyte, Tension Lipidosis                    1 (2%)                                                                       
      Hepatocyte, Vacuolization Cytoplasmic,                                                                                        
          Diffuse                                     10 (17%)      4 (7%)                                                          
      Hepatocyte, Vacuolization Cytoplasmic, Focal     4 (7%)       5 (8%)       2 (4%)       1 (2%)                                
      Hepatocyte, Periportal, Atrophy                                                         1 (2%)                                
      Hepatocyte, Centrilobular, Depletion Glycogen                 1 (2%)                    3 (5%)                                
      Hepatocyte, Centrilobular, Fatty Change          1 (2%)       2 (3%)       5 (9%)       1 (2%)                                
      Hepatocyte, Midzonal, Fatty Change                                                      1 (2%)                                
      Oval Cell, Hyperplasia                                                                  2 (3%)                                
   Mesentery                                          (12)         (12)         (42)         (38)                                   
      Inflammation, Chronic                            3 (25%)      2 (17%)      2 (5%)                                             
      Inflammation, Chronic, Focal                                               1 (2%)                                             
      Artery, Inflammation, Chronic                    3 (25%)      1 (8%)                                                          
      Fat, Necrosis                                    6 (50%)      1 (8%)       1 (2%)                                             
   Pancreas                                           (59)         (59)         (59)         (58)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Acinus, Atrophy, Focal                           1 (2%)       1 (2%)       1 (2%)                                             
      Duct, Cyst                                       1 (2%)       1 (2%)                                                          
      Duct, Inflammation, Chronic, Focal                            1 (2%)                                                          
   Stomach, Forestomach                               (60)         (60)         (58)         (60)                                   
      Inflammation, Focal                                           1 (2%)       3 (5%)       1 (2%)                                
      Necrosis, Focal                                                            1 (2%)                                             
      Ulcer                                                         1 (2%)       3 (5%)       1 (2%)                                
      Epithelium, Cyst                                 1 (2%)                                                                       
      Epithelium, Hyperplasia                          2 (3%)       5 (8%)       6 (10%)      3 (5%)                                
   Stomach, Glandular                                 (57)         (54)         (53)         (55)                                   
      Erosion                                                                    2 (4%)                                             
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
      Inflammation, Focal                                           1 (2%)                    1 (2%)                                
      Pigmentation, Focal                                                        1 (2%)                                             
   Tooth                                              (14)         (9)          (2)                                                 
      Malformation                                     5 (36%)                                                                      
      Peridontal Tissue, Inflammation, Chronic        10 (71%)      9 (100%)     1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (60)         (60)         (60)         (60)                                   
      Infiltration Cellular, Mixed Cell                             1 (2%)       3 (5%)       1 (2%)                                
      Inflammation, Chronic, Focal                     1 (2%)                    4 (7%)       1 (2%)                                
      Mineralization                                                             2 (3%)       1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (60)         (60)         (58)         (60)                                   
      Accessory Adrenal Cortical Nodule                             1 (2%)                                                          
      Cyst                                                          2 (3%)                                                          
      Cytoplasmic Alteration, Focal                    7 (12%)      2 (3%)                                                          
      Fibrosis                                                                   1 (2%)                                             
      Hypertrophy, Focal                                            1 (2%)                                                          
      Inflammation, Chronic, Focal                                                            1 (2%)                                
   Parathyroid Gland                                  (55)         (54)         (57)         (56)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Cyst                                                                       1 (2%)                                             
   Pituitary Gland                                    (53)         (50)         (50)         (46)                                   
      Pars Distalis, Cyst                              2 (4%)       1 (2%)                                                          
      Pars Distalis, Hyperplasia, Focal                                                       1 (2%)                                
      Rathke's Cleft, Cyst                                          1 (2%)                                                          
   Thyroid Gland                                      (59)         (59)         (59)         (59)                                   
      Degeneration, Cystic, Focal                     10 (17%)     11 (19%)      3 (5%)                                             
      Follicular Cell, Hyperplasia                                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (2)                       (2)          (3)                                    
      Pelvic, Inflammation, Chronic, Focal                                                    1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                                            (2)          (1)                                    
      Inflammation, Chronic                                                      1 (50%)      1 (100%)                              
   Epididymis                                         (60)         (60)         (60)         (60)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
   Preputial Gland                                    (60)         (59)         (59)         (60)                                   
      Degeneration, Cystic                            28 (47%)     27 (46%)     16 (27%)      1 (2%)                                
      Inflammation, Chronic                            1 (2%)       5 (8%)       1 (2%)                                             
   Prostate                                           (60)         (59)         (57)         (58)                                   
      Inflammation, Chronic                                         1 (2%)       7 (12%)      4 (7%)                                
   Seminal Vesicle                                    (60)         (60)         (60)         (60)                                   
      Congestion                                                                 1 (2%)       1 (2%)                                
      Dilatation                                       2 (3%)       1 (2%)       1 (2%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
      Inflammation, Suppurative                                                               1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (60)         (60)         (60)         (60)                                   
      Depletion Cellular                                            1 (2%)                                                          
      Hemorrhage, Focal                                             2 (3%)       1 (2%)                                             
      Hyperplasia                                                   3 (5%)       2 (3%)                                             
      Thrombosis                                                    1 (2%)                                                          
      Erythroid Cell, Depletion Cellular                                         1 (2%)                                             
   Lymph Node                                         (3)          (4)          (7)          (1)                                    
      Iliac, Hematopoietic Cell Proliferation                                    1 (14%)                                            
      Iliac, Hyperplasia                                                         1 (14%)                                            
      Mediastinal, Hemorrhage                          1 (33%)      1 (25%)      3 (43%)                                            
      Mediastinal, Hyperplasia                                      1 (25%)      1 (14%)                                            
      Mediastinal, Pigmentation                                     1 (25%)                                                         
      Pancreatic, Hemorrhage                                        1 (25%)                                                         
   Lymph Node, Mandibular                             (59)         (55)         (50)         (54)                                   
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Lymph Node, Mesenteric                             (60)         (55)         (56)         (53)                                   
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hemorrhage                                       1 (2%)       2 (4%)                                                          
      Hyperplasia                                                                1 (2%)                                             
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
   Spleen                                             (60)         (60)         (58)         (60)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Depletion Cellular                               1 (2%)       7 (12%)      2 (3%)                                             
      Hematopoietic Cell Proliferation                13 (22%)     24 (40%)     49 (84%)     60 (100%)                              
      Hyperplasia, Lymphoid                            2 (3%)       3 (5%)                                                          
      Pigmentation, Focal                              1 (2%)                                                                       
   Thymus                                             (57)         (52)         (45)         (54)                                   
      Atrophy                                                       3 (6%)       3 (7%)       6 (11%)                               
      Cyst                                             4 (7%)       3 (6%)       1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Epithelial Cell, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (60)         (60)         (60)         (60)                                   
      Ulcer, Chronic, Focal                            1 (2%)                                                                       
      Artery, Subcutaneous Tissue, Inflammation,                                                                                    
           Chronic                                     2 (3%)                                                                       
      Prepuce, Subcutaneous Tissue, Inflammation,                                                                                   
           Suppurative                                                           1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - CONT                                                                                                         
      Subcutaneous Tissue, Edema                                    3 (5%)      14 (23%)     22 (37%)                               
      Subcutaneous Tissue, Hemorrhage, Focal                                     1 (2%)       2 (3%)                                
      Subcutaneous Tissue, Inflammation, Chronic,                                                                                   
           Focal                                                    1 (2%)       1 (2%)       2 (3%)                                
      Subcutaneous Tissue, Necrosis                                              1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (60)         (60)         (60)         (60)                                   
      Fracture                                                      1 (2%)                                                          
   Skeletal Muscle                                    (1)          (6)          (35)         (47)                                   
      Hemorrhage, Focal                                                          2 (6%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (60)         (60)         (60)         (60)                                   
      Congestion                                                    1 (2%)       1 (2%)       1 (2%)                                
      Cyst                                                                       1 (2%)                                             
      Hemorrhage                                       1 (2%)                    1 (2%)       5 (8%)                                
      Hyperplasia, Histiocytic                                      2 (3%)                    1 (2%)                                
      Infiltration Cellular, Polymorphonuclear                                   1 (2%)                                             
      Infiltration Cellular, Mixed Cell                             4 (7%)       9 (15%)      3 (5%)                                
      Inflammation, Chronic, Focal                                  3 (5%)                                                          
      Alveolar Epithelium, Hyperplasia                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Bronchus, Glands, Cyst                           1 (2%)                                                                       
   Nose                                               (60)         (60)         (60)         (60)                                   
      Mucosa, Glands, Dilatation, Focal                             1 (2%)                                                          
      Nasolacrimal Duct, Inflammation                               1 (2%)                                                          
      Sinus, Foreign Body                              1 (2%)                                                                       
      Sinus, Inflammation, Chronic, Suppurative        1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                             (1)          (1)                                                 
      Atrophy                                                       1 (100%)                                                        
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   13                                                              
                                                                                                                                   
NTP Experiment-Test: 05203-09         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           O-NITROTOLUENE                                      Date: 11/16/00    
Route: DOSED FEED                                                                                                 Time: 09:50:01    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Inflammation, Chronic                                                      1 (100%)                                           
      Cornea, Necrosis, Focal                                                    1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (58)         (59)         (58)         (60)                                   
      Amyloid Deposition                                            1 (2%)                                                          
      Atrophy                                                       1 (2%)       1 (2%)                                             
      Atrophy, Focal                                                2 (3%)                                                          
      Congestion                                       5 (9%)       3 (5%)                                                          
      Cyst                                             2 (3%)       4 (7%)       1 (2%)       1 (2%)                                
      Fibrosis, Focal                                               2 (3%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)       3 (5%)                                                          
      Infarct                                                       1 (2%)                                                          
      Infiltration Cellular, Mixed Cell                                          1 (2%)                                             
      Inflammation, Chronic                                         1 (2%)       1 (2%)                                             
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
      Inflammation, Focal, Suppurative                              1 (2%)                                                          
      Inflammation, Suppurative                                     1 (2%)       3 (5%)                                             
      Metaplasia, Focal, Osseous                                                 1 (2%)                                             
      Nephropathy                                     56 (97%)     53 (90%)     34 (59%)     18 (30%)                               
      Artery, Inflammation, Chronic                    2 (3%)                                                                       
      Papilla, Necrosis                                                          1 (2%)                                             
      Pelvis, Dilatation                                                         2 (3%)                                             
      Renal Tubule, Accumulation, Hyaline Droplet      1 (2%)       2 (3%)       5 (9%)       3 (5%)                                
      Renal Tubule, Dilatation                                      1 (2%)       4 (7%)                                             
      Renal Tubule, Necrosis                                        1 (2%)                    2 (3%)                                
      Renal Tubule, Pigmentation                       1 (2%)       6 (10%)     32 (55%)     35 (58%)                               
      Renal Tubule, Vacuolization Cytoplasmic          1 (2%)                    1 (2%)                                             
   Urethra                                                                      (1)          (2)                                    
      Inflammation, Focal                                                        1 (100%)     2 (100%)                              
   Urinary Bladder                                    (59)         (59)         (59)         (60)                                   
      Calculus Micro Observation Only                                            1 (2%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
      Transitional Epithelium, Hyperplasia                                       1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
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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