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TDMS Study 92013-05 Pathology Tables

NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04
Route: DOSED FEED                                                                                                 Time: 08:36:49

                                                         FINAL #1 RATS




       Facility:  Southern Research Institute

       Chemical CAS #:  822-36-6

       Lock Date:  09/13/02

       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: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      2            6           11            6                                     
    Moribund Sacrifice                                 5            5            5            9                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                40           39           34           33                                     
    Natural Death                                      3                                      2                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (48)         (46)         (43)         (43)                                   
      Edema                                            1 (2%)                                                                       
   Liver                                              (50)         (50)         (48)         (50)                                   
      Basophilic Focus                                46 (92%)     43 (86%)     31 (65%)     25 (50%)                               
      Clear Cell Focus                                20 (40%)     32 (64%)     23 (48%)     27 (54%)                               
      Congestion                                       2 (4%)       2 (4%)                    1 (2%)                                
      Degeneration, Cystic, Focal                      1 (2%)                    1 (2%)       3 (6%)                                
      Eosinophilic Focus                               1 (2%)       2 (4%)       5 (10%)     11 (22%)                               
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Hemorrhage                                                                              1 (2%)                                
      Hepatodiaphragmatic Nodule                       5 (10%)      4 (8%)       6 (13%)     11 (22%)                               
      Histiocytosis                                   40 (80%)     50 (100%)    48 (100%)    50 (100%)                              
      Hyperplasia, Focal, Histiocytic                                                         2 (4%)                                
      Infiltration Cellular, Mixed Cell                5 (10%)      5 (10%)                   5 (10%)                               
      Inflammation, Chronic                           17 (34%)     28 (56%)     34 (71%)     35 (70%)                               
      Inflammation, Chronic, Focal                                               1 (2%)                                             
      Inflammation, Granulomatous                      1 (2%)                                                                       
      Mixed Cell Focus                                10 (20%)      7 (14%)      6 (13%)     18 (36%)                               
      Thrombosis                                                                 1 (2%)                                             
      Bile Duct, Cyst                                                                         1 (2%)                                
      Bile Duct, Dilatation, Focal                                               2 (4%)       1 (2%)                                
      Bile Duct, Hyperplasia                          31 (62%)     38 (76%)     43 (90%)     35 (70%)                               
      Hepatocyte, Fatty Change, Focal                 16 (32%)     29 (58%)     29 (60%)     32 (64%)                               
      Hepatocyte, Hyperplasia, Focal                   1 (2%)                                                                       
      Hepatocyte, Necrosis, Focal                      1 (2%)                                 1 (2%)                                
      Hepatocyte, Vacuolization Cytoplasmic            6 (12%)     12 (24%)     17 (35%)     11 (22%)                               
      Hepatocyte, Centrilobular, Necrosis              2 (4%)                    1 (2%)       1 (2%)                                
      Oval Cell, Hyperplasia, Focal                    1 (2%)                                 2 (4%)                                
      Serosa, Fibrosis                                                           1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
   Mesentery                                          (9)          (7)          (11)         (8)                                    
      Inflammation, Chronic                            1 (11%)                   1 (9%)                                             
      Fat, Necrosis, Focal                             8 (89%)      3 (43%)                   1 (13%)                               
      Lymphatic, Angiectasis                                                                  1 (13%)                               
   Pancreas                                           (49)         (49)         (47)         (47)                                   
      Acinus, Atrophy, Diffuse                         1 (2%)                                                                       
      Acinus, Atrophy, Focal                          13 (27%)     22 (45%)     26 (55%)     30 (64%)                               
      Duct, Cyst, Focal, Multiple                     10 (20%)     18 (37%)     11 (23%)      9 (19%)                               
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy, Focal                                                             2 (4%)                                             
      Inflammation, Chronic                                         1 (2%)       1 (2%)       1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (49)         (50)                                   
      Diverticulum                                                               1 (2%)                                             
      Edema                                            1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Inflammation                                                               2 (4%)                                             
      Ulcer                                            1 (2%)       1 (2%)       3 (6%)       2 (4%)                                
      Epithelium, Hyperplasia                                       1 (2%)       6 (12%)      1 (2%)                                
   Stomach, Glandular                                 (50)         (50)         (49)         (49)                                   
      Erosion                                          2 (4%)       1 (2%)       1 (2%)       4 (8%)                                
      Ulcer                                                         1 (2%)                                                          
   Tongue                                                          (5)          (4)          (3)                                    
      Epithelium, Hyperplasia                                       1 (20%)      1 (25%)                                            
   Tooth                                              (1)          (1)          (2)                                                 
      Malformation                                                  1 (100%)     2 (100%)                                           
      Peridontal Tissue, Inflammation                  1 (100%)     1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (48)         (50)                                   
      Cardiomyopathy                                  30 (60%)     43 (86%)     38 (79%)     44 (88%)                               
      Inflammation, Focal, Suppurative                              1 (2%)                                                          
      Thrombosis                                                                 2 (4%)       5 (10%)                               
      Artery, Inflammation, Chronic                                              1 (2%)                                             
      Epicardium, Inflammation                         1 (2%)                                                                       
      Myocardium, Fibrosis, Focal                      1 (2%)                                                                       
      Pericardium, Infiltration Cellular, Mixed                                                                                     
        Cell                                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (49)         (50)         (50)         (50)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Accessory Adrenal Cortical Nodule                8 (16%)      6 (12%)      3 (6%)       2 (4%)                                
      Angiectasis                                      4 (8%)       2 (4%)       7 (14%)      4 (8%)                                
      Cytoplasmic Alteration, Focal                    1 (2%)       2 (4%)       2 (4%)       2 (4%)                                
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hemorrhage, Focal                                                          2 (4%)       1 (2%)                                
      Vacuolization Cytoplasmic, Focal                 8 (16%)      9 (18%)     13 (26%)     12 (24%)                               
   Adrenal Medulla                                    (48)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                                 1 (2%)                                
      Atrophy                                                                    1 (2%)                                             
      Hyperplasia, Focal                               2 (4%)                    2 (4%)                                             
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
   Islets, Pancreatic                                 (49)         (50)         (48)         (47)                                   
      Atrophy                                                                    1 (2%)                                             
   Parathyroid Gland                                  (50)         (49)         (48)         (49)                                   
      Hyperplasia, Focal                                                                      1 (2%)                                
   Pituitary Gland                                    (48)         (50)         (50)         (50)                                   
      Angiectasis                                      6 (13%)      4 (8%)       3 (6%)       4 (8%)                                
      Cyst                                                          4 (8%)       2 (4%)       5 (10%)                               
      Hyperplasia, Focal, Histiocytic                               1 (2%)                                                          
      Pars Distalis, Angiectasis                       1 (2%)       2 (4%)       3 (6%)                                             
      Pars Distalis, Degeneration, Cystic, Focal       9 (19%)      6 (12%)      5 (10%)      3 (6%)                                
      Pars Distalis, Hemorrhage, Focal                                           1 (2%)                                             
      Pars Distalis, Hyperplasia, Focal                4 (8%)       4 (8%)       5 (10%)      4 (8%)                                
      Pars Distalis, Hypertrophy, Focal                1 (2%)                    1 (2%)       4 (8%)                                
   Thyroid Gland                                      (47)         (44)         (40)         (45)                                   
      C-Cell, Hyperplasia                             45 (96%)     42 (95%)     36 (90%)     35 (78%)                               
      Follicle, Cyst                                                1 (2%)                                                          
      Follicle, Degeneration, Focal                                              1 (3%)       1 (2%)                                
      Follicle, Mineralization                         2 (4%)       7 (16%)      6 (15%)     19 (42%)                               
      Follicular Cell, Hyperplasia, Focal              1 (2%)       1 (2%)       1 (3%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (5)          (3)          (6)          (6)                                    
      Fibrosis, Focal                                  1 (20%)                                                                      
      Mediastinum, Cyst                                1 (20%)                                                                      
      Mediastinum, Infiltration Cellular, Mixed                                                                                     
        Cell                                           1 (20%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Clitoral Gland                                     (50)         (50)         (50)         (50)                                   
      Degeneration, Cystic                             4 (8%)                    5 (10%)      3 (6%)                                
      Hyperplasia, Cystic                              7 (14%)      4 (8%)       1 (2%)       1 (2%)                                
      Hyperplasia, Focal, Histiocytic                                            1 (2%)                                             
      Inflammation, Chronic                            2 (4%)       2 (4%)                    3 (6%)                                
   Ovary                                              (50)         (50)         (48)         (50)                                   
      Angiectasis                                                                             2 (4%)                                
      Cyst                                             7 (14%)      3 (6%)       5 (10%)                                            
      Periovarian Tissue, Hemorrhage                                                          1 (2%)                                
   Uterus                                             (50)         (50)         (48)         (50)                                   
      Inflammation, Chronic, Granulomatous             1 (2%)                                                                       
      Ulcer                                                                      1 (2%)                                             
      Cervix, Hypertrophy                              1 (2%)                                                                       
      Endometrium, Hyperplasia, Cystic                25 (50%)     26 (52%)     18 (38%)     26 (52%)                               
   Vagina                                             (1)          (2)          (5)          (4)                                    
      Angiectasis                                                                             1 (25%)                               
      Infiltration Cellular, Polymorphonuclear                      1 (50%)                   1 (25%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (48)         (49)         (48)                                   
      Atrophy                                                                                 2 (4%)                                
      Fibrosis                                                      1 (2%)       1 (2%)                                             
      Hyperplasia                                      3 (6%)       2 (4%)       1 (2%)       2 (4%)                                
      Hyperplasia, Focal, Histiocytic                               1 (2%)       2 (4%)       3 (6%)                                
      Erythroid Cell, Hyperplasia                                   1 (2%)                                                          
   Lymph Node                                         (24)         (11)         (24)         (35)                                   
      Hyperplasia, Plasma Cell                                                                1 (3%)                                
      Deep Cervical, Hemorrhage                        3 (13%)                                                                      
      Mediastinal, Congestion                                       1 (9%)                                                          
      Mediastinal, Ectasia                             3 (13%)      1 (9%)                    1 (3%)                                
      Mediastinal, Hemorrhage                          5 (21%)      3 (27%)      5 (21%)      3 (9%)                                
      Mediastinal, Hyperplasia, Histiocytic            4 (17%)      1 (9%)       1 (4%)       6 (17%)                               
      Mediastinal, Hyperplasia, Lymphoid               1 (4%)                                 1 (3%)                                
      Mediastinal, Hyperplasia, Plasma Cell                                      1 (4%)                                             
      Mediastinal, Pigmentation                        1 (4%)                                                                       
      Pancreatic, Hemorrhage                           1 (4%)                    2 (8%)       2 (6%)                                
      Pancreatic, Hyperplasia, Histiocytic             6 (25%)      1 (9%)       7 (29%)      7 (20%)                               
      Pancreatic, Hyperplasia, Lymphoid                                                       1 (3%)                                
      Pancreatic, Hyperplasia, Plasma Cell             1 (4%)                                                                       
      Pancreatic, Pigmentation                         1 (4%)                                                                       
      Renal, Hyperplasia, Histiocytic                                                         1 (3%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Lymph Node, Mandibular                             (1)          (3)          (1)          (4)                                    
      Ectasia                                                       1 (33%)                                                         
      Hyperplasia, Histiocytic                                                                1 (25%)                               
      Hyperplasia, Lymphoid                                                      1 (100%)                                           
   Lymph Node, Mesenteric                             (49)         (49)         (49)         (47)                                   
      Ectasia                                                                    2 (4%)                                             
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Histiocytic                         7 (14%)                   1 (2%)       2 (4%)                                
      Hyperplasia, Lymphoid                                                                   1 (2%)                                
   Spleen                                             (50)         (48)         (47)         (48)                                   
      Accessory Spleen                                 3 (6%)                    1 (2%)       1 (2%)                                
      Atrophy                                                                    2 (4%)                                             
      Congestion                                                                 1 (2%)                                             
      Fibrosis, Focal                                  1 (2%)                    1 (2%)       1 (2%)                                
      Hematopoietic Cell Proliferation                 6 (12%)      2 (4%)                                                          
      Inflammation, Granulomatous                                   3 (6%)      10 (21%)      3 (6%)                                
      Stromal Hyperplasia                                           1 (2%)                                                          
      Capsule, Infiltration Cellular, Focal, Mixed                                                                                  
        Cell                                                                     2 (4%)       1 (2%)                                
   Thymus                                             (47)         (50)         (48)         (48)                                   
      Angiectasis                                                                1 (2%)                                             
      Cyst                                             2 (4%)                                                                       
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)       1 (2%)                                
      Epithelial Cell, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (49)         (50)         (50)                                   
      Dilatation                                      37 (74%)     16 (33%)      8 (16%)      1 (2%)                                
      Fibrosis                                         1 (2%)                                                                       
      Hyperplasia                                      6 (12%)      3 (6%)       3 (6%)       1 (2%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Inflammation, Focal                                                        1 (2%)                                             
      Ulcer                                            1 (2%)       1 (2%)                    1 (2%)                                
      Epidermis, Hyperplasia, Focal                                              1 (2%)       2 (4%)                                
      Lip, Cyst Epithelial Inclusion                                                          1 (2%)                                
      Pinna, Inflammation, Chronic, Focal                           1 (2%)                                                          
      Subcutaneous Tissue, Edema                       1 (2%)       1 (2%)                    1 (2%)                                
      Subcutaneous Tissue, Fibrosis, Focal                          1 (2%)                                                          
      Subcutaneous Tissue, Hemorrhage, Focal                                     1 (2%)                                             
      Subcutaneous Tissue, Necrosis, Fatty, Focal                                1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression, Focal                              13 (26%)      8 (16%)      8 (16%)      2 (4%)                                
      Hemorrhage, Focal                                1 (2%)       2 (4%)       4 (8%)       2 (4%)                                
      Meninges, Hemorrhage, Focal                                                             1 (2%)                                
      Thalamus, Mineralization, Focal                                            1 (2%)       1 (2%)                                
   Spinal Cord                                        (7)          (3)          (24)         (50)                                   
      Hemorrhage, Focal                                                                       2 (4%)                                
      Necrosis, Focal                                                                         1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       1 (2%)       5 (10%)      3 (6%)       5 (10%)                               
      Hemorrhage, Focal                                1 (2%)                    2 (4%)       2 (4%)                                
      Hyperplasia, Focal, Histiocytic                               1 (2%)                    2 (4%)                                
      Infiltration Cellular, Mixed Cell                3 (6%)       1 (2%)                    1 (2%)                                
      Inflammation, Chronic, Focal                    25 (50%)     40 (80%)     39 (78%)     43 (86%)                               
      Alveolar Epithelium, Hyperplasia, Focal          4 (8%)       3 (6%)                    2 (4%)                                
      Interstitium, Edema                              1 (2%)                    1 (2%)                                             
      Mediastinum, Congestion                                                    1 (2%)                                             
      Mediastinum, Edema                               1 (2%)       1 (2%)       1 (2%)                                             
      Mediastinum, Mineralization, Focal                                         1 (2%)                                             
   Nose                                               (49)         (50)         (50)         (50)                                   
      Foreign Body                                                  2 (4%)                                                          
      Inflammation, Suppurative                                     3 (6%)       1 (2%)                                             
      Nasolacrimal Duct, Hemorrhage                                                           1 (2%)                                
      Nasolacrimal Duct, Inflammation                  2 (4%)       5 (10%)      4 (8%)       5 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (48)         (45)         (40)         (45)                                   
      Atrophy                                                                    3 (8%)       4 (9%)                                
      Cataract                                         4 (8%)                    1 (3%)       1 (2%)                                
      Inflammation, Chronic                                         1 (2%)                    1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0 PPM        1250 PPM     2500 PPM     5000 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Synechia                                         1 (2%)                                 2 (4%)                                
      Anterior Chamber, Exudate                                     1 (2%)                    1 (2%)                                
      Cornea, Inflammation, Chronic                                 1 (2%)                                                          
      Cornea, Necrosis, Focal                                       1 (2%)       1 (3%)       2 (4%)                                
      Retina, Degeneration                             4 (8%)       1 (2%)                    3 (7%)                                
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Cytoplasmic Alteration, Focal                                              1 (2%)                                             
      Hyperplasia, Focal, Histiocytic                  1 (2%)       4 (8%)       5 (10%)                                            
      Inflammation                                     1 (2%)       1 (2%)                                                          
      Epithelium, Hyperplasia, Focal                                             1 (2%)                                             
   Zymbal's Gland                                                  (3)          (1)                                                 
      Cyst                                                          1 (33%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (48)         (48)         (43)         (43)                                   
      Cyst                                                                       2 (5%)                                             
      Hydronephrosis                                                                          1 (2%)                                
      Infarct                                          1 (2%)       1 (2%)       1 (2%)       2 (5%)                                
      Mineralization, Focal                                         1 (2%)                                                          
      Nephropathy                                     45 (94%)     37 (77%)     36 (84%)     38 (88%)                               
      Pelvis, Dilatation                               1 (2%)                                                                       
      Renal Tubule, Accumulation, Hyaline Droplet      3 (6%)                    2 (5%)       1 (2%)                                
      Renal Tubule, Hyperplasia, Focal                                                        1 (2%)                                
      Renal Tubule, Pigmentation                                                              2 (5%)                                
   Urinary Bladder                                    (49)         (50)         (49)         (48)                                   
      Hemorrhage                                                                 1 (2%)       2 (4%)                                
      Inflammation                                                               1 (2%)       1 (2%)                                
      Transitional Epithelium, Hyperplasia                                       1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                13           11           12           10                                     
    Natural Death                                      6            5            5            8                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                31           34           33           32                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (46)         (46)         (46)         (46)                                   
      Congestion                                                    1 (2%)                                                          
      Edema                                                                                   1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis, Focal                                            1 (2%)                                                          
      Atrophy, Focal                                                             1 (2%)                                             
      Basophilic Focus                                31 (62%)     26 (52%)     30 (60%)     36 (72%)                               
      Clear Cell Focus                                31 (62%)     28 (56%)     29 (58%)     31 (62%)                               
      Congestion                                       2 (4%)                                                                       
      Degeneration, Cystic, Focal                      4 (8%)       3 (6%)       1 (2%)       7 (14%)                               
      Eosinophilic Focus                               4 (8%)       3 (6%)       7 (14%)     12 (24%)                               
      Fibrosis                                         1 (2%)                                                                       
      Hepatodiaphragmatic Nodule                       5 (10%)      2 (4%)       5 (10%)      4 (8%)                                
      Histiocytosis                                   38 (76%)     45 (90%)     50 (100%)    50 (100%)                              
      Hyperplasia, Focal, Histiocytic                  1 (2%)                    1 (2%)       3 (6%)                                
      Infiltration Cellular, Mixed Cell               15 (30%)      5 (10%)      5 (10%)     17 (34%)                               
      Inflammation, Chronic                           18 (36%)     32 (64%)     31 (62%)     36 (72%)                               
      Inflammation, Granulomatous                      1 (2%)                                                                       
      Mixed Cell Focus                                 5 (10%)      7 (14%)     11 (22%)     27 (54%)                               
      Thrombosis                                                                 1 (2%)                                             
      Bile Duct, Dilatation, Focal                     2 (4%)       2 (4%)       2 (4%)       2 (4%)                                
      Bile Duct, Hyperplasia                          48 (96%)     48 (96%)     49 (98%)     42 (84%)                               
      Hepatocyte, Fatty Change, Focal                 21 (42%)     24 (48%)     37 (74%)     33 (66%)                               
      Hepatocyte, Necrosis, Focal                                   2 (4%)       1 (2%)                                             
      Hepatocyte, Vacuolization Cytoplasmic           11 (22%)     14 (28%)     12 (24%)     18 (36%)                               
      Serosa, Inflammation, Chronic, Focal             1 (2%)                                                                       
   Mesentery                                          (13)         (10)         (11)         (10)                                   
      Inflammation, Chronic                                                      1 (9%)       1 (10%)                               
      Artery, Thrombosis                                                                      1 (10%)                               
      Fat, Hemorrhage, Focal                           1 (8%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Fat, Necrosis, Focal                             9 (69%)      4 (40%)      6 (55%)      5 (50%)                               
   Oral Mucosa                                        (1)          (1)          (1)                                                 
      Foreign Body                                                  1 (100%)                                                        
      Hyperplasia, Focal, Squamous                                               1 (100%)                                           
      Inflammation, Chronic, Focal                                  1 (100%)                                                        
   Pancreas                                           (50)         (48)         (48)         (49)                                   
      Angiectasis                                                                1 (2%)                                             
      Inflammation, Chronic                                                                   1 (2%)                                
      Acinus, Atrophy, Diffuse                                                   1 (2%)                                             
      Acinus, Atrophy, Focal                          23 (46%)     24 (50%)     24 (50%)     25 (51%)                               
      Duct, Cyst, Focal, Multiple                     15 (30%)     12 (25%)     16 (33%)     10 (20%)                               
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy, Focal                                   1 (2%)                                                                       
      Inflammation, Chronic                                         1 (2%)                                                          
   Stomach, Forestomach                               (50)         (50)         (50)         (49)                                   
      Diverticulum                                                                            1 (2%)                                
      Edema                                            3 (6%)                                                                       
      Hyperkeratosis, Focal                                         1 (2%)                                                          
      Inflammation                                     1 (2%)                    1 (2%)       3 (6%)                                
      Ulcer                                            5 (10%)      2 (4%)       2 (4%)       3 (6%)                                
      Epithelium, Hyperplasia                          4 (8%)       3 (6%)       2 (4%)       4 (8%)                                
   Stomach, Glandular                                 (50)         (50)         (49)         (49)                                   
      Cyst                                                                                    1 (2%)                                
      Edema                                            2 (4%)                                                                       
      Erosion                                          3 (6%)       1 (2%)       1 (2%)       6 (12%)                               
      Hyperplasia, Focal, Histiocytic                                            1 (2%)                                             
      Inflammation, Focal                                           1 (2%)                                                          
      Ulcer                                            1 (2%)       1 (2%)       2 (4%)                                             
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Tongue                                                          (3)          (1)          (1)                                    
      Epithelium, Cyst                                              1 (33%)                                                         
      Epithelium, Hyperplasia                                                    1 (100%)     1 (100%)                              
   Tooth                                              (1)          (1)                                                              
      Peridontal Tissue, Inflammation                  1 (100%)     1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  40 (80%)     38 (76%)     36 (72%)     39 (78%)                               
      Thrombosis                                       1 (2%)       3 (6%)       1 (2%)       4 (8%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule                9 (18%)      6 (12%)      5 (10%)      9 (18%)                               
      Angiectasis                                                   1 (2%)                                                          
      Cytoplasmic Alteration, Focal                    3 (6%)       2 (4%)       1 (2%)       2 (4%)                                
      Degeneration, Cystic                                          1 (2%)                                                          
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Hemorrhage, Focal                                1 (2%)                                                                       
      Hyperplasia, Focal                                                                      1 (2%)                                
      Necrosis                                         1 (2%)       1 (2%)       1 (2%)                                             
      Vacuolization Cytoplasmic, Focal                 6 (12%)      5 (10%)     13 (26%)      7 (14%)                               
      Capsule, Hyperplasia, Focal                                                             1 (2%)                                
   Adrenal Medulla                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia, Focal                               7 (14%)      1 (2%)       3 (6%)                                             
      Necrosis                                                      1 (2%)                                                          
   Islets, Pancreatic                                 (50)         (49)         (49)         (49)                                   
      Hyperplasia                                      1 (2%)                                 1 (2%)                                
   Parathyroid Gland                                  (48)         (50)         (48)         (50)                                   
      Hyperplasia, Focal                               1 (2%)                                 2 (4%)                                
   Pituitary Gland                                    (49)         (49)         (48)         (48)                                   
      Angiectasis                                      1 (2%)                    4 (8%)       1 (2%)                                
      Cyst                                             4 (8%)       2 (4%)       6 (13%)      1 (2%)                                
      Fibrosis, Focal                                                                         1 (2%)                                
      Hemorrhage                                                                              1 (2%)                                
      Pars Distalis, Cytoplasmic Alteration, Focal                               2 (4%)                                             
      Pars Distalis, Degeneration, Cystic, Focal                    1 (2%)                                                          
      Pars Distalis, Hemorrhage, Focal                 2 (4%)                                                                       
      Pars Distalis, Hyperplasia                       1 (2%)                                                                       
      Pars Distalis, Hyperplasia, Focal                3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
      Pars Distalis, Hypertrophy, Focal                8 (16%)      9 (18%)     20 (42%)     22 (46%)                               
      Pars Nervosa, Inflammation                       1 (2%)                                                                       
   Thyroid Gland                                      (47)         (46)         (48)         (44)                                   
      C-Cell, Hyperplasia                             41 (87%)     28 (61%)     26 (54%)     29 (66%)                               
      Follicle, Cyst                                                3 (7%)       1 (2%)       5 (11%)                               
      Follicle, Degeneration, Focal                    6 (13%)      4 (9%)       8 (17%)      4 (9%)                                
      Follicle, Mineralization                         3 (6%)       3 (7%)       5 (10%)      6 (14%)                               
      Follicular Cell, Hyperplasia, Focal              1 (2%)       1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                      (2)          (3)          (1)                                    
      Inflammation, Chronic, Focal                                               1 (33%)                                            
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENERAL BODY SYSTEM - CONT                                                                                                          
   Tissue NOS                                         (6)          (4)          (6)          (5)                                    
      Inflammation, Chronic                                                                   1 (20%)                               
      Mediastinum, Cyst                                1 (17%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                                                         (1)                                    
      Inflammation, Chronic                                                                   1 (100%)                              
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                  1 (2%)                                 1 (2%)                                
      Hemorrhage                                                                              1 (2%)                                
      Inflammation, Chronic                                                      1 (2%)                                             
      Spermatocele                                     1 (2%)                                                                       
   Preputial Gland                                    (50)         (50)         (50)         (49)                                   
      Degeneration, Cystic                             5 (10%)      3 (6%)       2 (4%)       3 (6%)                                
      Fibrosis                                         1 (2%)                                                                       
      Hyperplasia, Cystic                              3 (6%)       1 (2%)                                                          
      Inflammation, Chronic                           30 (60%)     28 (56%)     21 (42%)     23 (47%)                               
   Prostate                                           (50)         (50)         (50)         (49)                                   
      Inflammation, Chronic                           27 (54%)     24 (48%)     28 (56%)     36 (73%)                               
      Epithelium, Hyperplasia, Focal                   4 (8%)       6 (12%)      5 (10%)                                            
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Dilatation                                                                              1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Atrophy                                         15 (30%)     10 (20%)      8 (16%)     10 (20%)                               
      Cyst                                             1 (2%)                                                                       
      Interstitial Cell, Hyperplasia, Focal            4 (8%)                    6 (12%)      7 (14%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (47)         (50)         (48)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Atrophy                                          1 (2%)                                                                       
      Hyperplasia                                      2 (4%)       3 (6%)       2 (4%)       4 (8%)                                
   Lymph Node                                         (19)         (18)         (26)         (27)                                   
      Hyperplasia, Plasma Cell                                      1 (6%)                                                          
      Deep Cervical, Hyperplasia, Histiocytic                                    1 (4%)                                             
      Deep Cervical, Hyperplasia, Plasma Cell          1 (5%)                                                                       
      Mediastinal, Ectasia                             2 (11%)      2 (11%)                   3 (11%)                               
      Mediastinal, Hemorrhage                          3 (16%)      2 (11%)      2 (8%)       3 (11%)                               
      Mediastinal, Hyperplasia                                      1 (6%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Mediastinal, Hyperplasia, Histiocytic            5 (26%)                   2 (8%)       3 (11%)                               
      Mediastinal, Hyperplasia, Plasma Cell            2 (11%)      2 (11%)      2 (8%)       1 (4%)                                
      Pancreatic, Ectasia                              1 (5%)                                                                       
      Pancreatic, Fibrosis                                                                    1 (4%)                                
      Pancreatic, Hemorrhage                                        1 (6%)       3 (12%)      1 (4%)                                
      Pancreatic, Hyperplasia, Histiocytic             2 (11%)                   1 (4%)       4 (15%)                               
   Lymph Node, Mesenteric                             (50)         (48)         (48)         (49)                                   
      Ectasia                                          1 (2%)       1 (2%)                                                          
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Histiocytic                         2 (4%)       1 (2%)                    2 (4%)                                
      Hyperplasia, Lymphoid                                                                   1 (2%)                                
   Spleen                                             (50)         (48)         (48)         (49)                                   
      Accessory Spleen                                 3 (6%)                    1 (2%)       3 (6%)                                
      Atrophy                                          3 (6%)                                                                       
      Fibrosis, Diffuse                                1 (2%)                                                                       
      Fibrosis, Focal                                  2 (4%)       2 (4%)       2 (4%)                                             
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Hemorrhage                                       1 (2%)                    1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                                 1 (2%)                                
      Infarct                                                       1 (2%)                    2 (4%)                                
      Inflammation, Granulomatous                                   2 (4%)       1 (2%)       2 (4%)                                
   Thymus                                             (48)         (49)         (46)         (45)                                   
      Angiectasis                                                                1 (2%)                                             
      Hemorrhage                                       2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (47)         (46)         (41)         (45)                                   
      Dilatation                                      12 (26%)      7 (15%)      1 (2%)       2 (4%)                                
      Fibrosis                                         1 (2%)                                 1 (2%)                                
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                        1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Hyperkeratosis, Focal                            1 (2%)                    1 (2%)                                             
      Inflammation, Focal                                                                     1 (2%)                                
      Ulcer                                                         1 (2%)                                                          
      Epidermis, Hyperplasia, Focal                                 1 (2%)       1 (2%)                                             
      Subcutaneous Tissue, Edema                                                 1 (2%)                                             
      Subcutaneous Tissue, Fibrosis, Focal                                                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                             Page   13                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Vertebra, Cyst                                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression, Focal                               4 (8%)       6 (12%)      1 (2%)       1 (2%)                                
      Hemorrhage, Focal                                1 (2%)       4 (8%)       3 (6%)       3 (6%)                                
      Meninges, Congestion, Focal                                   1 (2%)                                                          
      Meninges, Hemorrhage, Focal                      1 (2%)                                                                       
   Spinal Cord                                        (2)          (3)          (2)          (3)                                    
      Hemorrhage, Focal                                             1 (33%)                   1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       4 (8%)       1 (2%)                    2 (4%)                                
      Hemorrhage, Focal                                4 (8%)       1 (2%)       3 (6%)                                             
      Infiltration Cellular, Mixed Cell                3 (6%)                    1 (2%)       2 (4%)                                
      Inflammation, Chronic, Focal                     3 (6%)       3 (6%)       4 (8%)       2 (4%)                                
      Inflammation, Focal                                                                     1 (2%)                                
      Alveolar Epithelium, Hyperplasia, Focal          2 (4%)       4 (8%)       3 (6%)                                             
      Alveolus, Proteinosis                                                      1 (2%)                                             
   Nose                                               (49)         (50)         (50)         (50)                                   
      Foreign Body                                     1 (2%)                    1 (2%)       1 (2%)                                
      Hemorrhage                                       1 (2%)                                                                       
      Inflammation, Suppurative                        2 (4%)       1 (2%)       4 (8%)       2 (4%)                                
      Nasolacrimal Duct, Inflammation                                                         4 (8%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (48)         (47)         (48)         (45)                                   
      Cataract                                         2 (4%)       1 (2%)                    2 (4%)                                
      Anterior Chamber, Exudate                                     1 (2%)                    2 (4%)                                
      Retina, Degeneration                             2 (4%)                                                                       
   Harderian Gland                                    (50)         (50)         (50)         (50)                                   
      Hyperplasia, Focal, Histiocytic                  1 (2%)                                                                       
      Hyperplasia, Focal, Lymphoid                                               1 (2%)                                             
      Inflammation                                                               2 (4%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   14                                                              
                                                                                                                                   
NTP Experiment-Test: 92013-05         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                         4-METHYLIMIDAZOLE                                     Date: 12/06/04    
Route: DOSED FEED                                                                                                 Time: 08:36:49    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0 PPM        625 PPM      1250 PPM     2500 PPM                                  
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Inflammation, Chronic                                                                   1 (2%)                                
      Epithelium, Hyperplasia, Focal                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (48)         (49)         (48)         (50)                                   
      Congestion                                       1 (2%)                                                                       
      Cyst                                             2 (4%)       1 (2%)                                                          
      Infarct                                                       2 (4%)       1 (2%)       4 (8%)                                
      Nephropathy                                     47 (98%)     43 (88%)     47 (98%)     46 (92%)                               
      Pelvis, Dilatation                                                         1 (2%)       1 (2%)                                
      Renal Tubule, Accumulation, Hyaline Droplet      1 (2%)       3 (6%)       2 (4%)       2 (4%)                                
      Renal Tubule, Hyperplasia, Focal                              1 (2%)                                                          
      Renal Tubule, Pigmentation                       1 (2%)       1 (2%)       2 (4%)                                             
   Urethra                                                                                   (1)                                    
      Muscularis, Inflammation, Chronic                                                       1 (100%)                              
   Urinary Bladder                                    (49)         (50)         (50)         (50)                                   
      Hemorrhage                                       1 (2%)       1 (2%)                    1 (2%)                                
      Inflammation                                     1 (2%)                                 1 (2%)                                
      Ulcer                                            1 (2%)                                                                       
      Muscularis, Hyperplasia                                                    1 (2%)                                             
      Transitional Epithelium, Hyperplasia                                       1 (2%)                                             
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   15                                                              
                                                                                                                                   
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                             ----------              END OF REPORT             ----------                                           
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