https://ntp.niehs.nih.gov/go/2145

TR 388 Mouse Pathology Tables

                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                          ETHYLENETHIOUREA
NTP Experiment-Test: 05076-02                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 09/10/94
Route: DOSED FEED                                                                                                 Time: 02:00:00
       Facility:  Battelle Columbus Laboratory
       Chemical CAS #:  96-45-7
       Lock Date:  None
       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: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           29           50           50           50           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 9            4            6            6           11            9           
    Natural Death                                      6            8            2            1            3            5           
  Survivors                                                                                                                         
    Terminal Sacrifice                                34           37           21           42           34           36           
    Natural Death                                      1            1                         1            2                        
  Animals Examined Microscopically                    50           50           29           50           50           50           
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Intestine Large, Colon                             (49)         (12)         (8)          (9)          (16)         (12)         
      Parasite Metazoan                                                                                    1 (6%)                   
   Intestine Small, Jejunum                           (46)         (12)         (10)         (8)          (19)         (13)         
      Inflammation, Chronic Active                                  1 (8%)                                                          
      Necrosis                                                                                                          1 (8%)      
      Peyer's Patch, Hyperplasia, Lymphoid                                       1 (10%)                                            
   Liver                                              (50)         (49)         (28)         (50)         (50)         (50)         
      Basophilic Focus                                 2 (4%)       1 (2%)                    3 (6%)       2 (4%)       1 (2%)      
      Clear Cell Focus                                              2 (4%)                    1 (2%)                    1 (2%)      
      Eosinophilic Focus                                                         2 (7%)      11 (22%)      4 (8%)      14 (28%)     
      Fatty Change, Focal                                                                                  1 (2%)                   
      Hematopoietic Cell Proliferation                 8 (16%)      2 (4%)       1 (4%)       1 (2%)       4 (8%)       2 (4%)      
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Infarct                                          3 (6%)       2 (4%)       2 (7%)       5 (10%)      6 (12%)      4 (8%)      
      Inflammation, Acute                              1 (2%)                                                           1 (2%)      
      Inflammation, Chronic Active                     2 (4%)                                              1 (2%)       1 (2%)      
      Necrosis                                         2 (4%)                                 1 (2%)                                
      Vacuolization Cytoplasmic                                                               1 (2%)                                
      Bile Duct, Mineralization, Multifocal                                                   1 (2%)                                
      Centrilobular, Cytomegaly                                                  2 (7%)      11 (22%)      8 (16%)      9 (18%)     
      Centrilobular, Necrosis                                                                 1 (2%)                                
      Centrilobular, Necrosis, Acute                                                                       1 (2%)                   
      Centrilobular, Vacuolization Cytoplasmic         2 (4%)                                 1 (2%)                                
      Oval Cell, Hyperplasia                                                                  1 (2%)                                
   Mesentery                                          (6)          (2)                       (1)          (1)          (1)          
      Inflammation, Chronic Active                     2 (33%)                                1 (100%)     1 (100%)                 
   Pancreas                                           (50)         (11)         (8)          (7)          (16)         (13)         
      Acinus, Atrophy                                  2 (4%)                    1 (13%)      1 (14%)      1 (6%)       2 (15%)     
      Acinus, Inflammation, Chronic Active                                                    1 (14%)                               
      Duct, Ectasia                                    2 (4%)                                              1 (6%)       2 (15%)     
   Salivary Glands                                    (50)         (13)         (8)          (8)          (15)         (14)         
      Perivascular, Inflammation, Chronic Active,                                                                                   
           Multifocal                                  1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
   Stomach, Forestomach                               (48)         (15)         (10)         (11)         (17)         (14)         
      Acanthosis                                                                              2 (18%)                               
      Cyst Epithelial Inclusion                                     2 (13%)      1 (10%)                                            
      Diverticulum                                                                                         1 (6%)                   
      Hyperkeratosis, Focal                                         1 (7%)                                                          
      Hyperplasia, Squamous                                                      1 (10%)                   3 (18%)                  
      Inflammation, Chronic Active                                  2 (13%)                                                         
   Stomach, Glandular                                 (48)         (11)         (8)          (8)          (15)         (13)         
      Dysplasia                                        1 (2%)                                                                       
      Subserosa, Inflammation, Chronic                                                        1 (13%)                               
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (13)         (8)          (8)          (16)         (14)         
      Bacterium, Acute, Multiple                       1 (2%)                                              2 (13%)                  
      Degeneration, Chronic                                                                                1 (6%)                   
      Inflammation, Acute                                                                                  2 (13%)                  
      Inflammation, Chronic                                                                                             1 (7%)      
      Mineralization                                                             1 (13%)      1 (13%)                               
      Thrombosis                                       1 (2%)                                 1 (13%)                               
      Interstitium, Hyperplasia, Diffuse                                                                                1 (7%)      
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Gland, Cortex                              (49)         (13)         (8)          (8)          (16)         (11)         
      Degeneration, Fatty                              4 (8%)                                                                       
      Hematopoietic Cell Proliferation                              1 (8%)                                                          
      Hyperplasia                                      1 (2%)                                                                       
      Hypertrophy                                      3 (6%)                                              1 (6%)       1 (9%)      
   Adrenal Gland, Medulla                             (48)         (13)         (8)          (8)          (16)         (11)         
      Hyperplasia                                                                             1 (13%)      1 (6%)                   
   Islets, Pancreatic                                 (49)         (13)         (8)          (7)          (15)         (12)         
      Hyperplasia, Focal                               1 (2%)                                                                       
   Pituitary Gland                                    (47)         (48)         (28)         (49)         (48)         (47)         
      Pars Distalis, Angiectasis                                    1 (2%)                                                          
      Pars Distalis, Hyperplasia                      19 (40%)     19 (40%)      8 (29%)     22 (45%)     23 (48%)     18 (38%)     
   Thyroid Gland                                      (50)         (49)         (29)         (50)         (50)         (49)         
      Follicular Cell, Hyperplasia                     2 (4%)       8 (16%)                  13 (26%)     17 (34%)     22 (45%)     
      Follicular Cell, Vacuolization Cytoplasmic       3 (6%)       1 (2%)      19 (66%)     49 (98%)     49 (98%)     44 (90%)     
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Clitoral Gland                                     (1)                                                 (1)                       
      Dilatation                                       1 (100%)                                            1 (100%)                 
   Ovary                                              (49)         (26)         (20)         (15)         (24)         (25)         
      Angiectasis                                                                2 (10%)                                            
      Hemorrhage                                                                                                        1 (4%)      
      Inflammation, Suppurative                        1 (2%)                                                           2 (8%)      
      Thrombosis                                                                 1 (5%)                                             
      Follicle, Cyst                                  16 (33%)      8 (31%)      8 (40%)      6 (40%)     11 (46%)      8 (32%)     
      Periovarian Tissue, Cyst                         3 (6%)       9 (35%)                   2 (13%)      3 (13%)      4 (16%)     
   Uterus                                             (48)         (33)         (13)         (19)         (20)         (20)         
      Angiectasis                                                                                                       2 (10%)     
      Dilatation                                       2 (4%)                                                           2 (10%)     
      Endometrium, Hyperplasia, Cystic, Glandular     39 (81%)     28 (85%)      7 (54%)     13 (68%)      8 (40%)      9 (45%)     
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (13)         (8)          (8)          (16)         (13)         
      Angiectasis                                                                             1 (13%)                               
      Femoral, Hyperplasia, Neutrophil                                                                                  1 (8%)      
      Femoral, Necrosis, Acute                                      1 (8%)                                                          
   Lymph Node                                         (49)         (18)         (15)         (19)         (25)         (19)         
      Lumbar, Sinus, Lymphatic, Ectasia                1 (2%)                                                                       
      Mandibular, Angiectasis                                       1 (6%)                                                          
      Mandibular, Hyperplasia, Lymphoid                2 (4%)       1 (6%)                                              1 (5%)      
      Mandibular, Hyperplasia, Reticulum Cell                                                                           1 (5%)      
      Mandibular, Infiltration Cellular, Plasma                                                                                     
          Cell                                         1 (2%)                                                                       
      Mediastinal, Hyperplasia, Lymphoid               1 (2%)                                                                       
   Lymph Node, Mesenteric                             (14)         (10)         (8)          (12)         (14)         (9)          
      Hematopoietic Cell Proliferation                 2 (14%)      1 (10%)      2 (25%)      2 (17%)      1 (7%)       1 (11%)     
      Hemorrhage                                       1 (7%)                                                                       
      Hyperplasia, Lymphoid                            1 (7%)                                                                       
      Inflammation, Chronic Active                                                                                      1 (11%)     
   Spleen                                             (50)         (23)         (13)         (28)         (31)         (34)         
      Fibrosis                                         1 (2%)                                                           1 (3%)      
      Hematopoietic Cell Proliferation                 5 (10%)      3 (13%)                   6 (21%)      6 (19%)      5 (15%)     
      Hyperplasia, Lymphoid                            3 (6%)       1 (4%)                    2 (7%)       3 (10%)      3 (9%)      
      Necrosis, Acute                                                                                      1 (3%)                   
   Thymus                                             (39)         (7)          (4)          (6)          (12)         (5)          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Depletion Lymphoid                                                                                   1 (8%)       1 (20%)     
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Mammary Gland                                      (35)         (13)         (8)          (8)          (16)         (11)         
      Hyperplasia, Cystic                              1 (3%)                                                                       
   Skin                                               (50)         (13)         (8)          (8)          (16)         (15)         
      Acanthosis                                       5 (10%)                   4 (50%)                   8 (50%)                  
      Parasite External                                6 (12%)                   6 (75%)                  11 (69%)      1 (7%)      
      Ulcer                                            1 (2%)                                                                       
      Subcutaneous Tissue, Fibrosis                    1 (2%)                                                                       
      Subcutaneous Tissue, Inflammation, Chronic                                                                                    
          Active                                                                                           1 (6%)                   
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   Bone                                               (50)         (13)         (9)          (9)          (16)         (14)         
      Tarsal, Hyperostosis                                                       2 (22%)      1 (11%)                               
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (13)         (8)          (8)          (16)         (14)         
      Compression                                      2 (4%)       1 (8%)       1 (13%)                                            
      Hemorrhage                                       2 (4%)                    1 (13%)                                            
      Hydrocephalus                                    2 (4%)                                                                       
      Perivascular, Inflammation, Chronic Active       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Lung                                               (50)         (50)         (29)         (50)         (50)         (50)         
      Alveolar Epithelium, Hyperplasia                 1 (2%)       1 (2%)                                 1 (2%)       1 (2%)      
      Artery, Embolus                                               1 (2%)                                                          
      Interstitium, Inflammation, Acute                1 (2%)                                                                       
      Mediastinum, Hyperplasia, Lymphoid               1 (2%)                                                                       
      Peribronchiolar, Inflammation, Chronic Active   13 (26%)      5 (10%)      2 (7%)       7 (14%)      1 (2%)       2 (4%)      
   Nose                                               (47)         (12)         (8)          (8)          (16)         (13)         
      Nasolacrimal Duct, Inflammation, Acute                        1 (8%)                                                          
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                             (2)                       (2)          (1)                       
      Atrophy                                                       1 (50%)                   2 (100%)     1 (100%)                 
      Lens, Cataract                                                1 (50%)                                                         
      Retina, Degeneration                                          1 (50%)                                                         
   Harderian Gland                                    (3)          (3)          (1)          (4)          (1)          (1)          
      Inflammation, Chronic Active                                                                         1 (100%)                 
   Lacrimal Gland                                     (1)                                                                           
      Inflammation, Chronic Active                     1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (12)         (8)          (11)         (16)         (15)         
      Hemorrhage                                                                 1 (13%)                                            
      Infarct                                          1 (2%)                                                                       
      Nephropathy, Chronic                                                       1 (13%)      1 (9%)                                
      Glomerulus, Dilatation                                        1 (8%)                                                          
      Glomerulus, Inflammation, Acute                                                                                   1 (7%)      
      Glomerulus, Inflammation, Chronic                                                                                 1 (7%)      
      Pelvis, Inflammation, Suppurative                1 (2%)                                                                       
      Renal Tubule, Cyst                               1 (2%)                                                                       
      Renal Tubule, Dilatation                                                                             1 (6%)                   
   Urinary Bladder                                    (48)         (12)         (8)          (9)          (13)         (11)         
      Inflammation, Acute                              1 (2%)                                                                       
      Inflammation, Chronic Active                                                                         1 (8%)                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50                                                               
  Early Deaths                                                                                                                      
    Natural Death                                      9            7                                                               
    Moribund Sacrifice                                10           14                                                               
  Survivors                                                                                                                         
    Natural Death                                      1                                                                            
    Terminal Sacrifice                                30           29                                                               
  Animals Examined Microscopically                    50           50                                                               
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Intestine Large, Cecum                             (50)         (48)                                                             
      Inflammation, Chronic Active                     1 (2%)                                                                       
   Intestine Large, Colon                             (50)         (49)                                                             
      Parasite Metazoan                                3 (6%)                                                                       
   Liver                                              (50)         (50)                                                             
      Angiectasis                                      1 (2%)                                                                       
      Eosinophilic Focus                               3 (6%)       2 (4%)                                                          
      Hematopoietic Cell Proliferation                 1 (2%)       2 (4%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Infarct                                         13 (26%)     22 (44%)                                                         
      Infiltration Cellular, Multifocal, Histiocyte                 1 (2%)                                                          
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Mixed Cell Focus                                 1 (2%)                                                                       
      Centrilobular, Cytomegaly                                     8 (16%)                                                         
      Centrilobular, Vacuolization Cytoplasmic         1 (2%)                                                                       
   Mesentery                                          (2)          (1)                                                              
      Inflammation, Chronic Active                                  1 (100%)                                                        
   Pancreas                                           (50)         (50)                                                             
      Acinus, Atrophy                                  1 (2%)       1 (2%)                                                          
      Duct, Ectasia                                    1 (2%)       1 (2%)                                                          
      Perivascular, Inflammation, Chronic Active                    1 (2%)                                                          
   Salivary Glands                                    (49)         (50)                                                             
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Perivascular, Inflammation, Chronic Active,                                                                                   
           Multifocal                                               1 (2%)                                                          
   Stomach, Forestomach                               (49)         (50)                                                             
      Acanthosis                                       1 (2%)       1 (2%)                                                          
      Diverticulum                                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (50)                                                             
      Degeneration, Chronic                                         1 (2%)                                                          
      Inflammation, Chronic                            1 (2%)                                                                       
      Mineralization                                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Gland, Cortex                              (49)         (50)                                                             
      Accessory Adrenal Cortical Nodule                1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Hypertrophy                                      1 (2%)       1 (2%)                                                          
   Adrenal Gland, Medulla                             (50)         (50)                                                             
      Hemorrhage, Chronic                              1 (2%)                                                                       
      Hyperplasia                                      1 (2%)                                                                       
   Pituitary Gland                                    (49)         (47)                                                             
      Pars Distalis, Cyst                                           1 (2%)                                                          
      Pars Distalis, Hyperplasia                      27 (55%)     28 (60%)                                                         
      Pars Distalis, Vacuolization Cytoplasmic                      2 (4%)                                                          
   Thyroid Gland                                      (50)         (50)                                                             
      Follicular Cell, Hyperplasia                    46 (92%)     46 (92%)                                                         
      Follicular Cell, Vacuolization Cytoplasmic      47 (94%)     48 (96%)                                                         
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Ovary                                              (50)         (48)                                                             
      Hyperplasia, Tubular                             1 (2%)                                                                       
      Inflammation, Suppurative                                     1 (2%)                                                          
      Follicle, Cyst                                   8 (16%)      7 (15%)                                                         
      Periovarian Tissue, Cyst                         2 (4%)       2 (4%)                                                          
      Periovarian Tissue, Hyperplasia, Lymphoid        1 (2%)                                                                       
   Uterus                                             (48)         (48)                                                             
      Angiectasis                                                   2 (4%)                                                          
      Dilatation                                       2 (4%)       5 (10%)                                                         
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
      Inflammation, Chronic Active                                  2 (4%)                                                          
      Endometrium, Hyperplasia, Cystic, Glandular      8 (17%)     11 (23%)                                                         
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (49)                                                             
      Femoral, Hyperplasia, Neutrophil                 1 (2%)       1 (2%)                                                          
      Femoral, Hyperplasia, Reticulum Cell                          1 (2%)                                                          
   Lymph Node                                         (47)         (49)                                                             
      Mandibular, Hyperplasia                                       1 (2%)                                                          
      Mandibular, Hyperplasia, Lymphoid                4 (9%)       2 (4%)                                                          
      Mediastinal, Hyperplasia, Lymphoid               1 (2%)       3 (6%)                                                          
   Lymph Node, Mesenteric                             (4)          (9)                                                              
      Inflammation, Chronic Active                     1 (25%)                                                                      
   Spleen                                             (49)         (50)                                                             
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hyperplasia, Lymphoid                            6 (12%)      2 (4%)                                                          
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (49)         (50)                                                             
      Acanthosis                                      17 (35%)      7 (14%)                                                         
      Cyst Epithelial Inclusion                                     1 (2%)                                                          
      Parasite External                               22 (45%)      7 (14%)                                                         
      Lip, Inflammation, Chronic                       1 (2%)                                                                       
      Subcutaneous Tissue, Inflammation, Chronic                                                                                    
          Active                                       2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (50)                                                             
      Compression                                      2 (4%)       2 (4%)                                                          
      Hydrocephalus                                                 2 (4%)                                                          
      Perivascular, Inflammation, Chronic Active                    1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Lung                                               (50)         (50)                                                             
      Hyperplasia, Lymphoid                            5 (10%)      2 (4%)                                                          
      Alveolar Epithelium, Hyperplasia                 1 (2%)       1 (2%)                                                          
      Peribronchiolar, Inflammation, Chronic Active    9 (18%)      6 (12%)                                                         
   Nose                                               (49)         (50)                                                             
      Mucosa, Inflammation, Acute                      1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                (1)          (2)                                                              
      Atrophy                                          1 (100%)     2 (100%)                                                        
   Harderian Gland                                    (4)          (3)                                                              
      Inflammation, Chronic Active                     1 (25%)                                                                      
      Acinus, Dilatation                               2 (50%)                                                                      
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (50)                                                             
      Hyperplasia, Lymphoid                                         2 (4%)                                                          
      Nephropathy, Chronic                             1 (2%)       1 (2%)                                                          
   Urinary Bladder                                    (49)         (49)                                                             
      Hyperplasia, Lymphoid                            4 (8%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50           34           50           50           50           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 8            7            5            8           10            5           
    Natural Death                                     11           10            2           10            8           13           
    Accidently Killed                                               5                                                               
  Survivors                                                                                                                         
    Moribund Sacrifice                                                                                                  1           
    Natural Death                                      1                         1            1                                     
    Terminal Sacrifice                                30           27           25           31           32           30           
  Missing                                                           1            1                                      1           
  Animals Examined Microscopically                    50           49           33           50           50           49           
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (40)         (12)         (6)          (10)         (13)         (11)         
      Inflammation, Chronic Active                     1 (3%)                                                                       
   Intestine Large, Cecum                             (45)         (19)         (7)          (17)         (14)         (13)         
      Inflammation, Acute                                                                                  1 (7%)                   
      Parasite Metazoan                                                          1 (14%)                                            
   Intestine Large, Colon                             (50)         (21)         (8)          (17)         (16)         (16)         
      Parasite Metazoan                                5 (10%)                                3 (18%)                   1 (6%)      
   Intestine Large, Rectum                            (48)         (19)         (8)          (17)         (15)         (16)         
      Parasite Metazoan                                                                                    1 (7%)                   
   Intestine Small, Ileum                             (44)         (18)         (7)          (16)         (14)         (13)         
      Parasite Metazoan                                                          1 (14%)                                            
   Intestine Small, Jejunum                           (45)         (20)         (10)         (18)         (16)         (18)         
      Inflammation, Chronic Active                     1 (2%)                                                                       
   Liver                                              (49)         (49)         (33)         (50)         (47)         (49)         
      Basophilic Focus                                 3 (6%)       5 (10%)      3 (9%)       5 (10%)      4 (9%)       3 (6%)      
      Clear Cell Focus                                 1 (2%)                    1 (3%)       3 (6%)       1 (2%)       5 (10%)     
      Eosinophilic Focus                               2 (4%)                                 8 (16%)      3 (6%)       3 (6%)      
      Fatty Change, Focal                              1 (2%)                                                                       
      Fibrosis                                                                                                          1 (2%)      
      Hematopoietic Cell Proliferation                 3 (6%)                                 1 (2%)       3 (6%)       4 (8%)      
      Infarct                                         14 (29%)      4 (8%)       2 (6%)       7 (14%)      3 (6%)       2 (4%)      
      Inflammation, Chronic Active                     5 (10%)      1 (2%)                    1 (2%)                                
      Mixed Cell Focus                                                                                                  2 (4%)      
      Necrosis                                                      2 (4%)                                                          
      Bile Duct, Cyst                                               3 (6%)                                              2 (4%)      
      Bile Duct, Hyperplasia                                                                  2 (4%)                                
      Central Vein, Thrombosis                                                                1 (2%)                    1 (2%)      
      Centrilobular, Cytomegaly                                     1 (2%)       6 (18%)     36 (72%)     33 (70%)     29 (59%)     
      Centrilobular, Necrosis                                                                                           1 (2%)      
      Centrilobular, Necrosis, Acute                                             1 (3%)       2 (4%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
   Mesentery                                          (6)          (1)                                    (1)          (1)          
      Angiectasis                                      1 (17%)                                                                      
      Inflammation, Chronic Active                     2 (33%)                                                          1 (100%)    
   Pancreas                                           (48)         (20)         (7)          (17)         (15)         (17)         
      Inflammation, Chronic Active                                                                         1 (7%)                   
      Acinus, Atrophy                                  5 (10%)                                             1 (7%)                   
      Acinus, Focal Cellular Change                    1 (2%)                                                                       
      Acinus, Inflammation, Chronic Active                                                    1 (6%)                    1 (6%)      
      Duct, Cyst                                       1 (2%)                                 1 (6%)                                
   Salivary Glands                                    (50)         (21)         (8)          (19)         (15)         (17)         
      Inflammation, Acute                              1 (2%)                                                                       
      Acinus, Atrophy                                  1 (2%)                                                                       
   Stomach, Forestomach                               (49)         (24)         (7)          (17)         (16)         (22)         
      Acanthosis                                       1 (2%)       1 (4%)                                 1 (6%)       1 (5%)      
      Cyst Epithelial Inclusion                                                                                         1 (5%)      
      Inflammation, Acute                              1 (2%)                                                                       
      Ulcer                                                                                                             1 (5%)      
   Stomach, Glandular                                 (48)         (21)         (7)          (17)         (15)         (18)         
      Infiltration Cellular, Lymphocyte                                          1 (14%)                                            
   Tooth                                              (5)                                                                           
      Incisor, Upper, Dysplasia                        3 (60%)                                                                      
      Peridontal Tissue, Infiltration Cellular,                                                                                     
           Mast Cell                                   1 (20%)                                                                      
      Peridontal Tissue, Inflammation, Suppurative     1 (20%)                                                                      
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (23)         (8)          (19)         (15)         (19)         
      Bacterium, Acute, Multiple                       1 (2%)                                                                       
      Degeneration, Chronic                                                      1 (13%)                                            
      Mineralization                                   1 (2%)                                                                       
      Thrombosis                                                    1 (4%)                                                          
      Valve, Inflammation, Suppurative                 1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Gland                                      (50)         (21)         (8)          (18)         (15)         (18)         
      Corticomedullary Junction, Cyst                  1 (2%)                                                                       
   Adrenal Gland, Cortex                              (50)         (21)         (8)          (18)         (15)         (18)         
      Hyperplasia                                      6 (12%)                                                          1 (6%)      
      Hypertrophy                                      8 (16%)                   1 (13%)                                1 (6%)      
   Adrenal Gland, Medulla                             (50)         (21)         (8)          (18)         (15)         (18)         
      Hyperplasia                                      3 (6%)                                                                       
   Pituitary Gland                                    (44)         (42)         (28)         (42)         (41)         (45)         
      Ectasia                                                                                 1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
ENDOCRINE SYSTEM - CONT                                                                                                             
      Craniopharyngeal Duct, Inflammation, Chronic                                                                                  
          Active                                                                              1 (2%)                                
      Pars Distalis, Cyst                                           2 (5%)       1 (4%)       1 (2%)       1 (2%)                   
      Pars Distalis, Hyperplasia                                                 1 (4%)       2 (5%)       2 (5%)       1 (2%)      
   Thyroid Gland                                      (50)         (46)         (33)         (49)         (47)         (48)         
      Artery, Inflammation, Chronic Active                                                                              1 (2%)      
      Follicular Cell, Hyperplasia                                  2 (4%)       1 (3%)                    3 (6%)       7 (15%)     
      Follicular Cell, Vacuolization Cytoplasmic                                25 (76%)     46 (94%)     43 (91%)     46 (96%)     
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Epididymis                                         (49)         (22)         (8)          (18)         (15)         (19)         
      Inflammation, Acute                                                                     1 (6%)                                
      Inflammation, Chronic Active                                                                                      2 (11%)     
   Preputial Gland                                    (2)          (2)          (1)          (2)          (4)          (3)          
      Inflammation, Chronic Active                     1 (50%)                   1 (100%)     2 (100%)     2 (50%)      2 (67%)     
      Inflammation, Suppurative                        1 (50%)      1 (50%)                                                         
      Duct, Dilatation                                 1 (50%)                                2 (100%)     2 (50%)      2 (67%)     
   Prostate                                           (50)         (22)         (8)          (18)         (15)         (19)         
      Inflammation, Chronic Active                                                            2 (11%)      1 (7%)       3 (16%)     
      Inflammation, Suppurative                        3 (6%)       3 (14%)                   2 (11%)                               
   Seminal Vesicle                                    (4)          (2)                       (1)          (1)          (1)          
      Dilatation                                       2 (50%)      2 (100%)                  1 (100%)     1 (100%)     1 (100%)    
      Inflammation, Suppurative                        1 (25%)                                                                      
   Testes                                             (50)         (22)         (8)          (20)         (14)         (19)         
      Seminiferous Tubule, Degeneration                1 (2%)       1 (5%)                    2 (10%)                               
      Seminiferous Tubule, Mineralization                                                     1 (5%)                                
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (21)         (8)          (18)         (13)         (19)         
      Femoral, Hyperplasia, Neutrophil                 1 (2%)       1 (5%)                    1 (6%)                    2 (11%)     
   Lymph Node                                         (48)         (25)         (15)         (22)         (20)         (22)         
      Lumbar, Hyperplasia, Lymphoid                                 1 (4%)                                                          
      Mandibular, Hyperplasia, Lymphoid                                                       2 (9%)                    1 (5%)      
      Mandibular, Infiltration Cellular, Histiocyte                 1 (4%)       1 (7%)                                             
   Lymph Node, Mesenteric                             (14)         (11)         (7)          (4)          (8)          (6)          
      Hematopoietic Cell Proliferation                11 (79%)      7 (64%)      1 (14%)      2 (50%)      3 (38%)                  
      Hemorrhage                                                                                                        1 (17%)     
      Hyperplasia, Lymphoid                                         2 (18%)      1 (14%)                                            
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Infiltration Cellular, Plasma Cell                                         1 (14%)                                            
      Inflammation, Chronic Active                                                                         1 (13%)      1 (17%)     
      Thrombosis                                       1 (7%)                                                                       
   Spleen                                             (49)         (25)         (12)         (21)         (24)         (24)         
      Depletion Lymphoid                               4 (8%)       1 (4%)                                 2 (8%)                   
      Hematopoietic Cell Proliferation                 3 (6%)       2 (8%)       2 (17%)      4 (19%)      5 (21%)      8 (33%)     
      Hyperplasia, Lymphoid                                         1 (4%)                    1 (5%)       1 (4%)       1 (4%)      
   Thymus                                             (29)         (11)         (4)          (11)         (11)         (11)         
      Depletion Lymphoid                                            1 (9%)                    1 (9%)       2 (18%)      1 (9%)      
      Necrosis, Diffuse                                1 (3%)       1 (9%)                    1 (9%)                                
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (50)         (26)         (14)         (23)         (25)         (26)         
      Acanthosis                                                    3 (12%)      4 (29%)      4 (17%)      3 (12%)      2 (8%)      
      Alopecia                                                                   1 (7%)                                             
      Hyperplasia, Basal Cell                                                    1 (7%)                                             
      Parasite External                                1 (2%)       4 (15%)      6 (43%)      5 (22%)      4 (16%)      5 (19%)     
      Ulcer                                            1 (2%)       3 (12%)                   3 (13%)      5 (20%)      3 (12%)     
      Prepuce, Inflammation, Acute                                                            1 (4%)                                
      Prepuce, Subcutaneous Tissue, Foreign Body                                              1 (4%)                                
      Subcutaneous Tissue, Edema                                    1 (4%)                                                          
      Subcutaneous Tissue, Fibrosis                    1 (2%)       1 (4%)       1 (7%)       2 (9%)       1 (4%)       1 (4%)      
      Subcutaneous Tissue, Granuloma                                             1 (7%)                                             
      Subcutaneous Tissue, Inflammation, Acute         1 (2%)       1 (4%)                                                          
      Subcutaneous Tissue, Inflammation, Chronic                                                                                    
          Active                                                    2 (8%)                    1 (4%)       2 (8%)                   
      Subcutaneous Tissue, Metaplasia, Osseous                                                             1 (4%)                   
      Subcutaneous Tissue, Sebaceous Gland,                                                                                         
          Hyperplasia                                                                         1 (4%)                                
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   Bone                                               (50)         (44)         (25)         (42)         (39)         (38)         
      Femur, Hyperostosis                                           1 (2%)                                                          
      Tarsal, Hyperostosis                            22 (44%)     24 (55%)     18 (72%)     28 (67%)     29 (74%)     29 (76%)     
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (21)         (8)          (19)         (15)         (19)         
      Infarct                                          1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Lung                                               (50)         (49)         (33)         (50)         (47)         (49)         
      Inflammation, Chronic, Diffuse                                                                       1 (2%)                   
      Metaplasia, Squamous                             1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)       2 (4%)       3 (9%)       2 (4%)       5 (11%)      3 (6%)      
      Alveolus, Hyperplasia, Macrophage                                                                    1 (2%)       1 (2%)      
      Artery, Embolus                                               1 (2%)                                                          
      Mediastinum, Inflammation                                                  1 (3%)                                             
      Peribronchial, Inflammation, Chronic Active                                                          2 (4%)       1 (2%)      
      Peribronchiolar, Inflammation, Chronic Active   26 (52%)      6 (12%)      5 (15%)     17 (34%)     16 (34%)      7 (14%)     
      Perivascular, Inflammation, Chronic Active                                                           2 (4%)       1 (2%)      
   Nose                                               (50)         (21)         (8)          (19)         (16)         (18)         
      Mucosa, Inflammation, Acute                      2 (4%)                                                           1 (6%)      
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                             (2)          (1)                                                 
      Atrophy                                                                    1 (100%)                                           
      Cornea, Inflammation, Chronic Active                          1 (50%)                                                         
   Harderian Gland                                    (4)          (1)          (3)          (3)          (1)          (3)          
      Hyperplasia                                      1 (25%)                                                                      
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (49)         (23)         (11)         (21)         (17)         (19)         
      Hydronephrosis                                   1 (2%)       2 (9%)                                                          
      Inflammation, Chronic Active                                  1 (4%)                                                          
      Metaplasia, Osseous                              1 (2%)                                                                       
      Nephropathy, Chronic                            32 (65%)      3 (13%)                   3 (14%)                   2 (11%)     
      Capsule, Fibrosis, Focal                                      1 (4%)       1 (9%)                                             
      Cortex, Cyst                                                               2 (18%)                   1 (6%)                   
      Cortex, Infiltration Cellular, Focal,                                                                                         
          Histiocyte                                                                                       1 (6%)                   
      Pelvis, Bacterium                                1 (2%)                                                                       
      Pelvis, Inflammation, Suppurative                2 (4%)                                 1 (5%)                                
      Renal Tubule, Mineralization                                                                                      1 (5%)      
      Renal Tubule, Necrosis                           1 (2%)       1 (4%)                                                          
   Urethra                                            (2)          (2)                       (1)                                    
      Inflammation, Chronic Active                                                            1 (100%)                              
      Inflammation, Suppurative                        2 (100%)     1 (50%)                                                         
      Bulbourethral Gland, Dilatation                               1 (50%)                                                         
   Urinary Bladder                                    (49)         (20)         (8)          (17)         (15)         (16)         
      Calculus Gross Observation                                    2 (10%)                                                         
      Dilatation                                       2 (4%)       3 (15%)      2 (25%)      2 (12%)                   2 (13%)     
      Inflammation, Chronic Active                     3 (6%)       2 (10%)                   1 (6%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   15                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0 PPM        0 PPM        100 PPM      333 PPM      333 PPM      333 PPM         
                                                   0-0          10-0           1-1          0-3          3-3          10-3          
____________________________________________________________________________________________________________________________________
URINARY SYSTEM - CONT                                                                                                               
      Mineralization                                   2 (4%)                                                                       
      Mucosa, Hyperplasia                                                                     1 (6%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   16                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           50                                                               
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                14           10                                                               
    Natural Death                                     13           15                                                               
  Survivors                                                                                                                         
    Terminal Sacrifice                                22           24                                                               
    Natural Death                                      1            1                                                               
  Animals Examined Microscopically                    50           50                                                               
____________________________________________________________________________________________________________________________________
 ALIMENTARY SYSTEM                                                                                                                  
   Gallbladder                                        (33)         (27)                                                             
      Epithelium, Hypertrophy, Focal                                1 (4%)                                                          
   Intestine Large, Cecum                             (42)         (40)                                                             
      Parasite Metazoan                                             3 (8%)                                                          
   Intestine Large, Colon                             (49)         (45)                                                             
      Inflammation, Acute, Necrotizing                 1 (2%)                                                                       
      Parasite Metazoan                                8 (16%)      9 (20%)                                                         
   Intestine Large, Rectum                            (46)         (41)                                                             
      Parasite Metazoan                                4 (9%)       4 (10%)                                                         
   Intestine Small, Ileum                             (43)         (40)                                                             
      Parasite Metazoan                                4 (9%)       1 (3%)                                                          
   Intestine Small, Jejunum                           (44)         (40)                                                             
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Lymphatic, Ectasia                                            1 (3%)                                                          
   Liver                                              (50)         (49)                                                             
      Basophilic Focus                                              1 (2%)                                                          
      Eosinophilic Focus                               2 (4%)      11 (22%)                                                         
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Infarct                                         33 (66%)     34 (69%)                                                         
      Centrilobular, Cytomegaly                       25 (50%)     40 (82%)                                                         
      Oval Cell, Hyperplasia                                        2 (4%)                                                          
   Mesentery                                          (5)          (3)                                                              
      Angiectasis                                      1 (20%)                                                                      
      Inflammation, Acute, Necrotizing                 1 (20%)                                                                      
      Inflammation, Chronic Active                     1 (20%)                                                                      
   Pancreas                                           (45)         (47)                                                             
      Acinus, Atrophy                                  4 (9%)       2 (4%)                                                          
      Duct, Ectasia                                                 1 (2%)                                                          
      Perivascular, Inflammation, Chronic Active       1 (2%)                                                                       
   Salivary Glands                                    (50)         (49)                                                             
      Acinus, Atrophy                                  1 (2%)                                                                       
      Perivascular, Inflammation, Suppurative          1 (2%)                                                                       
   Stomach, Forestomach                               (49)         (45)                                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   17                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT                                                                                                            
      Acanthosis                                       1 (2%)                                                                       
      Inflammation, Acute                              1 (2%)                                                                       
   Stomach, Glandular                                 (48)         (44)                                                             
      Dysplasia                                        1 (2%)                                                                       
      Infiltration Cellular, Mast Cell                              1 (2%)                                                          
      Inflammation, Acute                                           1 (2%)                                                          
      Inflammation, Chronic                            2 (4%)                                                                       
   Tooth                                              (4)          (1)                                                              
      Incisor, Upper, Dysplasia                        1 (25%)                                                                      
      Peridontal Tissue, Inflammation, Suppurative     2 (50%)      1 (100%)                                                        
____________________________________________________________________________________________________________________________________
 CARDIOVASCULAR SYSTEM                                                                                                              
   Heart                                              (50)         (50)                                                             
      Bacterium, Acute, Multiple                       1 (2%)                                                                       
      Degeneration, Chronic                                         1 (2%)                                                          
      Mineralization                                                1 (2%)                                                          
      Thrombosis                                                    1 (2%)                                                          
      Artery, Inflammation, Chronic Active             1 (2%)                                                                       
      Valve, Bacterium                                              1 (2%)                                                          
      Valve, Inflammation, Suppurative                 1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 ENDOCRINE SYSTEM                                                                                                                   
   Adrenal Gland, Cortex                              (50)         (49)                                                             
      Hyperplasia                                      3 (6%)       3 (6%)                                                          
      Hypertrophy                                     10 (20%)      7 (14%)                                                         
   Adrenal Gland, Medulla                             (50)         (49)                                                             
      Hyperplasia                                      2 (4%)       4 (8%)                                                          
   Pituitary Gland                                    (41)         (39)                                                             
      Pars Distalis, Hyperplasia                      32 (78%)     25 (64%)                                                         
   Thyroid Gland                                      (50)         (49)                                                             
      Follicular Cell, Hyperplasia                    44 (88%)     47 (96%)                                                         
      Follicular Cell, Vacuolization Cytoplasmic      47 (94%)     46 (94%)                                                         
____________________________________________________________________________________________________________________________________
 GENERAL BODY SYSTEM                                                                                                                
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   18                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
 GENITAL SYSTEM                                                                                                                     
   Epididymis                                         (49)         (49)                                                             
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Arteriole, Inflammation, Chronic Active          1 (2%)                                                                       
   Preputial Gland                                    (2)          (1)                                                              
      Inflammation, Chronic Active                     1 (50%)                                                                      
      Inflammation, Suppurative                        1 (50%)                                                                      
      Duct, Dilatation                                 1 (50%)      1 (100%)                                                        
   Prostate                                           (47)         (49)                                                             
      Inflammation, Suppurative                        1 (2%)       2 (4%)                                                          
      Arteriole, Inflammation, Chronic Active          1 (2%)                                                                       
   Seminal Vesicle                                    (2)                                                                           
      Dilatation                                       1 (50%)                                                                      
   Testes                                             (50)         (49)                                                             
      Arteriole, Inflammation, Chronic Active          1 (2%)                                                                       
      Seminiferous Tubule, Degeneration                1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 HEMATOPOIETIC SYSTEM                                                                                                               
   Bone Marrow                                        (49)         (47)                                                             
      Femoral, Hyperplasia, Neutrophil                 1 (2%)                                                                       
   Lymph Node                                         (47)         (48)                                                             
      Lumbar, Necrosis                                              1 (2%)                                                          
      Pancreatic, Necrosis                                          1 (2%)                                                          
   Lymph Node, Mesenteric                             (7)          (5)                                                              
      Hematopoietic Cell Proliferation                 3 (43%)      2 (40%)                                                         
   Spleen                                             (48)         (47)                                                             
      Hematopoietic Cell Proliferation                 3 (6%)       1 (2%)                                                          
   Thymus                                             (16)         (16)                                                             
      Necrosis, Diffuse                                2 (13%)                                                                      
____________________________________________________________________________________________________________________________________
 INTEGUMENTARY SYSTEM                                                                                                               
   Skin                                               (49)         (50)                                                             
      Acanthosis                                                    1 (2%)                                                          
      Parasite External                               28 (57%)      6 (12%)                                                         
      Subcutaneous Tissue, Edema                       1 (2%)                                                                       
      Subcutaneous Tissue, Fibrosis                    1 (2%)       1 (2%)                                                          
      Subcutaneous Tissue, Inflammation, Chronic                                                                                    
          Active                                       5 (10%)                                                                      
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   19                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
 MUSCULOSKELETAL SYSTEM                                                                                                             
   Bone                                               (50)         (50)                                                             
      Tarsal, Hyperostosis                            15 (30%)     24 (48%)                                                         
____________________________________________________________________________________________________________________________________
 NERVOUS SYSTEM                                                                                                                     
   Brain                                              (50)         (49)                                                             
      Infarct                                          1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
 RESPIRATORY SYSTEM                                                                                                                 
   Lung                                               (50)         (49)                                                             
      Inflammation, Chronic, Diffuse                   1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)       4 (8%)                                                          
      Alveolus, Hyperplasia, Macrophage                1 (2%)                                                                       
      Arteriole, Capillary, Inflammation,                                                                                           
          Suppurative                                  1 (2%)                                                                       
      Artery, Mediastinum, Inflammation,                                                                                            
          Suppurative                                  1 (2%)                                                                       
      Peribronchiolar, Inflammation, Acute,                                                                                         
          Necrotizing                                  1 (2%)                                                                       
      Peribronchiolar, Inflammation, Chronic Active   21 (42%)     18 (37%)                                                         
      Perivascular, Inflammation, Chronic Active       1 (2%)                                                                       
   Nose                                               (50)         (49)                                                             
      Mucosa, Inflammation, Acute                      1 (2%)       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
 SPECIAL SENSES SYSTEM                                                                                                              
   Eye                                                (6)          (2)                                                              
      Atrophy                                          5 (83%)      2 (100%)                                                        
      Inflammation                                     1 (17%)                                                                      
      Inflammation, Suppurative                        1 (17%)                                                                      
   Harderian Gland                                    (18)         (6)                                                              
      Inflammation, Chronic Active                    10 (56%)      2 (33%)                                                         
      Inflammation, Suppurative                        5 (28%)      1 (17%)                                                         
      Necrosis                                                      1 (17%)                                                         
____________________________________________________________________________________________________________________________________
 URINARY SYSTEM                                                                                                                     
   Kidney                                             (50)         (49)                                                             
      Infarct                                                       1 (2%)                                                          
      Nephropathy, Chronic                            22 (44%)     17 (35%)                                                         
      Pelvis, Inflammation, Suppurative                1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   20                                                              
NTP Experiment-Test: 05076-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          ETHYLENETHIOUREA                                     Date: 09/10/94  
Route: DOSED FEED                                                                                                 Time: 02:00:00  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          1000 PPM     1000 PPM                                                            
                                                      0-10         10-10                                                            
____________________________________________________________________________________________________________________________________
URINARY SYSTEM - CONT                                                                                                               
      Renal Tubule, Necrosis                           1 (2%)       1 (2%)                                                          
   Urethra                                            (3)          (1)                                                              
      Inflammation, Suppurative                        3 (100%)     1 (100%)                                                        
   Urinary Bladder                                    (48)         (48)                                                             
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Arteriole, Inflammation, Chronic Active          1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   21                                                              
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