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TDMS Study 88035-06 Pathology Tables

NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96
Route: DOSED FEED                                                                                                 Time: 16:42:44




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  0000125-33-7

       Lock Date:  11/17/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Merge     001   001                      0 PPM
                               Merge     002   002                      0 PPM
                               Merge     003   003                      300 PPM
                               Merge     004   004                      300 PPM
                               Merge     005   005                      600 PPM
                               Merge     006   006                      600 PPM
                               Merge     007   007                      1300 PPM
                               Merge     008   008                      1300 PPM





























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

                                                              Page   1


NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      2            7            2            3                                     
    Moribund Sacrifice                                 7            1            3            8                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                41           42           44           39                                     
  Missing                                                                        1                                                  

  Animals Examined Microscopically                    50           50           49           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Small, Duodenum                          (50)         (49)         (49)         (50)                                   
      Ulcer, Chronic, Focal                                                                   1 (2%)                                
   Intestine Small, Jejunum                           (50)         (49)         (49)         (50)                                   
      Peyer's Patch, Hyperplasia, Lymphoid             1 (2%)                                                                       
      Serosa, Inflammation, Chronic, Granulomatous     1 (2%)                                                                       
   Liver                                              (50)         (50)         (49)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Basophilic Focus                                 1 (2%)       1 (2%)                    1 (2%)                                
      Clear Cell Focus                                 1 (2%)       4 (8%)       1 (2%)       4 (8%)                                
      Congestion                                                                 1 (2%)                                             
      Eosinophilic Focus                               8 (16%)     23 (46%)     24 (49%)     17 (34%)                               
      Hematopoietic Cell Proliferation                 3 (6%)       2 (4%)       2 (4%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
      Mixed Cell Focus                                 1 (2%)       1 (2%)                                                          
      Necrosis                                         4 (8%)                    2 (4%)       3 (6%)                                
      Thrombosis, Diffuse                              1 (2%)                                                                       
      Centrilobular, Hypertrophy                       1 (2%)      11 (22%)     11 (22%)     21 (42%)                               
      Centrilobular, Necrosis                          1 (2%)                                                                       
      Hepatocyte, Vacuolization Cytoplasmic            3 (6%)      35 (70%)     39 (80%)     28 (56%)                               
   Mesentery                                          (5)          (5)          (6)          (2)                                    
      Fat, Inflammation, Chronic                       4 (80%)      5 (100%)     5 (83%)      2 (100%)                              
   Pancreas                                           (50)         (48)         (49)         (50)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
      Acinus, Atrophy                                  2 (4%)       2 (4%)       1 (2%)       1 (2%)                                
      Duct, Cyst                                                                              1 (2%)                                
   Salivary Glands                                    (50)         (48)         (49)         (50)                                   
      Duct, Cyst                                                                              1 (2%)                                
   Stomach, Forestomach                               (50)         (49)         (49)         (50)                                   
      Hyperplasia, Focal, Squamous                     4 (8%)      11 (22%)      3 (6%)       7 (14%)                               
   Stomach, Glandular                                 (50)         (49)         (49)         (50)                                   
      Necrosis, Focal                                                                         1 (2%)                                
      Polyp, Inflammatory                                           1 (2%)                                                          
____________________________________________________________________________________________________________________________________

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

                                                             Page    2                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (49)         (49)         (50)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (49)         (50)                                   
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hyperplasia, Focal                               1 (2%)                                                                       
      Hypertrophy, Focal                                            2 (4%)       2 (4%)       1 (2%)                                
      Capsule, Hyperplasia                             2 (4%)                    1 (2%)                                             
      Zona Reticularis, Angiectasis, Focal             1 (2%)                                                                       
      Zona Reticularis, Vacuolization Cytoplasmic                                             1 (2%)                                
   Adrenal Medulla                                    (50)         (49)         (49)         (50)                                   
      Hyperplasia                                                                1 (2%)                                             
   Islets, Pancreatic                                 (50)         (47)         (49)         (50)                                   
      Hyperplasia                                     15 (30%)     17 (36%)      6 (12%)      5 (10%)                               
   Pituitary Gland                                    (49)         (48)         (49)         (48)                                   
      Pars Distalis, Angiectasis                       1 (2%)                    1 (2%)                                             
      Pars Distalis, Hemorrhage                        1 (2%)                                                                       
      Pars Distalis, Hyperplasia                      13 (27%)     12 (25%)     19 (39%)     10 (21%)                               
      Pars Intermedia, Hyperplasia                                               1 (2%)       1 (2%)                                
      Rathke's Cleft, Cyst                                                       1 (2%)                                             
   Thyroid Gland                                      (50)         (48)         (48)         (50)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
      Follicle, Cyst                                                1 (2%)                                                          
      Follicular Cell, Hyperplasia                    13 (26%)     12 (25%)     28 (58%)     49 (98%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (47)         (45)         (48)         (48)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
   Ovary                                              (49)         (49)         (48)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Atrophy                                         37 (76%)     47 (96%)     39 (81%)     42 (84%)                               
      Hematocyst                                       5 (10%)                   1 (2%)       1 (2%)                                
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia, Cystic                                                        1 (2%)                                             
      Inflammation, Chronic, Granulomatous             1 (2%)                                                                       

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

                                                             Page    3                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Follicle, Cyst                                  12 (24%)      7 (14%)      9 (19%)      9 (18%)                               
      Periovarian Tissue, Cyst                                      2 (4%)                                                          
   Uterus                                             (50)         (49)         (49)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Hydrometra                                      28 (56%)     23 (47%)     17 (35%)     20 (40%)                               
      Inflammation, Suppurative                                     2 (4%)       2 (4%)                                             
      Endometrium, Hyperplasia, Cystic                36 (72%)     39 (80%)     42 (86%)     42 (84%)                               
      Endometrium, Inflammation, Chronic Active                     1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (49)         (50)                                   
      Depletion Cellular                               1 (2%)                                                                       
      Myelofibrosis, Focal                                                       1 (2%)                                             
      Myeloid Cell, Hyperplasia                        1 (2%)       1 (2%)       3 (6%)       2 (4%)                                
   Lymph Node                                         (6)          (8)          (7)          (4)                                    
      Lumbar, Infiltration Cellular, Histiocyte        1 (17%)                   1 (14%)                                            
      Lumbar, Pigmentation                             1 (17%)                                                                      
      Mediastinal, Hyperplasia, Lymphoid                                         1 (14%)      3 (75%)                               
      Renal, Infiltration Cellular, Histiocyte                                   1 (14%)                                            
   Lymph Node, Mandibular                             (48)         (44)         (45)         (46)                                   
      Cyst                                                          1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)                    2 (4%)                                
      Infiltration Cellular, Plasma Cell               1 (2%)                                                                       
      Infiltration Cellular, Histiocyte                                          1 (2%)                                             
   Lymph Node, Mesenteric                             (48)         (48)         (47)         (47)                                   
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hyperplasia, Lymphoid                            5 (10%)      2 (4%)                    4 (9%)                                
   Spleen                                             (50)         (48)         (49)         (50)                                   
      Atrophy                                                                                 1 (2%)                                
      Hematopoietic Cell Proliferation                14 (28%)     13 (27%)     13 (27%)     23 (46%)                               
      Hyperplasia, Lymphoid                            5 (10%)      5 (10%)      7 (14%)      4 (8%)                                
      Thrombosis                                                    1 (2%)                                                          
   Thymus                                             (45)         (47)         (44)         (44)                                   
      Angiectasis                                                                1 (2%)                                             
      Atrophy                                         30 (67%)     35 (74%)     37 (84%)     35 (80%)                               
      Hyperplasia, Lymphoid                            6 (13%)      5 (11%)      3 (7%)       2 (5%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (49)         (50)                                   
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Ulcer, Chronic Active                                                      1 (2%)                                             
      Subcutaneous Tissue, Cyst, Chronic Active                                               1 (2%)                                
      Subcutaneous Tissue, Edema                                    1 (2%)                                                          

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

                                                             Page    4                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (49)         (50)                                   
      Alveolar Epithelium, Hyperplasia, Focal          2 (4%)       3 (6%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                                                                           
      Retina, Atrophy                                  1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (49)         (50)                                   
      Cyst                                                                       1 (2%)                                             
      Hydronephrosis                                                             1 (2%)                                             
      Infiltration Cellular, Lymphocyte                1 (2%)                                 2 (4%)                                
      Nephropathy                                      7 (14%)      3 (6%)       6 (12%)      3 (6%)                                
      Renal Tubule, Pigmentation, Hemosiderin          1 (2%)                    1 (2%)       1 (2%)                                
                                                                                                                                    

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

                                                             Page    5                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 6            7            6           17                                     
    Natural Death                                      9            9           13           14                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           33           31           19                                     
    Natural Death                                                   1                                                               

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Small, Duodenum                          (44)         (48)         (48)         (45)                                   
      Necrosis, Focal                                                                         1 (2%)                                
      Ulcer                                                                      1 (2%)       1 (2%)                                
   Intestine Small, Jejunum                           (46)         (49)         (50)         (47)                                   
      Peyer's Patch, Hyperplasia, Lymphoid             1 (2%)                                                                       
   Intestine Small, Ileum                             (42)         (47)         (49)         (48)                                   
      Congestion                                                                              1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      2 (4%)       1 (2%)                                                          
      Basophilic Focus                                 2 (4%)       1 (2%)                                                          
      Clear Cell Focus                                11 (22%)      7 (14%)      8 (16%)      1 (2%)                                
      Clear Cell Focus, Multiple                       6 (12%)      4 (8%)       2 (4%)                                             
      Eosinophilic Focus                               7 (14%)      4 (8%)       8 (16%)      5 (10%)                               
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       2 (4%)                                             
      Inflammation, Chronic                                         2 (4%)                    1 (2%)                                
      Mixed Cell Focus                                 1 (2%)       1 (2%)                    1 (2%)                                
      Necrosis                                         6 (12%)      7 (14%)      6 (12%)      6 (12%)                               
      Thrombosis, Acute                                                          1 (2%)                                             
      Centrilobular, Hypertrophy                       3 (6%)      30 (60%)     21 (42%)     18 (36%)                               
      Hepatocyte, Vacuolization Cytoplasmic            1 (2%)       8 (16%)      3 (6%)       2 (4%)                                
   Mesentery                                          (1)          (2)          (1)          (1)                                    
      Fat, Inflammation, Chronic                       1 (100%)     1 (50%)      1 (100%)     1 (100%)                              
   Pancreas                                           (46)         (48)         (50)         (47)                                   
      Duct, Cyst                                       1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
   Stomach, Forestomach                               (50)         (49)         (50)         (49)                                   
      Hyperplasia, Diffuse, Squamous                   2 (4%)                                                                       
      Hyperplasia, Focal, Squamous                     6 (12%)      9 (18%)      9 (18%)      3 (6%)                                
   Stomach, Glandular                                 (50)         (49)         (50)         (49)                                   
      Epithelium, Hyperplasia, Focal                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    6                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Focal, Lymphocyte                                                1 (2%)                                
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Mineralization, Diffuse                                                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (50)                                   
      Hyperplasia, Focal                                                                      2 (4%)                                
      Hypertrophy, Focal                               2 (4%)       2 (4%)       2 (4%)       1 (2%)                                
      Necrosis                                                                                1 (2%)                                
      Capsule, Accessory Adrenal Cortical Nodule                                 1 (2%)                                             
      Capsule, Hyperplasia                             3 (6%)       4 (8%)       2 (4%)                                             
   Islets, Pancreatic                                 (45)         (48)         (49)         (47)                                   
      Hyperplasia                                     32 (71%)     34 (71%)     18 (37%)      4 (9%)                                
   Pituitary Gland                                    (45)         (46)         (48)         (47)                                   
      Pars Distalis, Cyst                                           2 (4%)       1 (2%)                                             
   Thyroid Gland                                      (49)         (48)         (50)         (50)                                   
      Follicle, Cyst                                                1 (2%)       1 (2%)                                             
      Follicular Cell, Hyperplasia                     8 (16%)     20 (42%)     31 (62%)     42 (84%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm, Focal                           1 (2%)                                                                       
      Spermatocele, Focal                                                        1 (2%)                                             
   Preputial Gland                                    (50)         (50)         (48)         (50)                                   
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Duct, Cyst                                      23 (46%)     32 (64%)     26 (54%)     30 (60%)                               
   Prostate                                           (49)         (50)         (50)         (50)                                   
      Inflammation, Chronic Active                                                            1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Germinal Epithelium, Atrophy                     1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    7                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Myeloid Cell, Hyperplasia                        2 (4%)       1 (2%)                    1 (2%)                                
   Lymph Node                                         (1)          (4)          (1)          (3)                                    
      Hyperplasia, Lymphoid                                                                   1 (33%)                               
      Inflammation, Chronic                                                                   1 (33%)                               
      Mediastinal, Hyperplasia, Lymphoid                            1 (25%)                                                         
      Renal, Hematopoietic Cell Proliferation                                                 1 (33%)                               
      Renal, Hyperplasia, Lymphoid                                               1 (100%)                                           
   Lymph Node, Mandibular                             (39)         (43)         (46)         (46)                                   
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
      Infiltration Cellular, Plasma Cell                            1 (2%)                                                          
   Lymph Node, Mesenteric                             (48)         (48)         (49)         (42)                                   
      Angiectasis                                                                             1 (2%)                                
      Congestion                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                              1 (2%)       1 (2%)       2 (5%)                                
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
   Spleen                                             (48)         (49)         (50)         (49)                                   
      Atrophy                                          2 (4%)       3 (6%)                    4 (8%)                                
      Hematopoietic Cell Proliferation                14 (29%)     15 (31%)     26 (52%)     37 (76%)                               
      Infiltration Cellular, Plasma Cell                                         1 (2%)                                             
      Capsule, Fibrosis                                                                       1 (2%)                                
   Thymus                                             (42)         (40)         (42)         (34)                                   
      Atrophy                                         39 (93%)     36 (90%)     35 (83%)     29 (85%)                               
      Hyperplasia, Lymphoid                                         1 (3%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Hyperplasia, Squamous                                                                   1 (2%)                                
      Inflammation, Chronic Active                                               1 (2%)       2 (4%)                                
      Ulcer                                                         1 (2%)       1 (2%)       2 (4%)                                
      Subcutaneous Tissue, Edema                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Hyperostosis                                                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    8                                                              
NTP Experiment-Test: 88035-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                             PRIMACLONE                                        Date: 12/30/96  
Route: DOSED FEED                                                                                                 Time: 16:42:44  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          0 PPM        300 PPM      600 PPM      1300 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Focal, Mast Cell          1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia, Focal          4 (8%)       6 (12%)      3 (6%)       3 (6%)                                
      Perivascular, Inflammation, Chronic                                                     1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (50)         (50)                                   
      Hydronephrosis                                   1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Focal, Mast Cell          1 (2%)                                                                       
      Inflammation, Acute                                                                     1 (2%)                                
      Nephropathy                                     34 (68%)     30 (61%)     25 (50%)     20 (40%)                               
      Cortex, Cyst                                     1 (2%)                    1 (2%)                                             
      Cortex, Infarct, Focal                           1 (2%)                                                                       
      Renal Tubule, Pigmentation, Hemosiderin                       7 (14%)      8 (16%)      2 (4%)                                
                                                                                                                                    

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

                                                             Page    9                                                              
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