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TDMS Study 93023-07 Pathology Tables

NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01
Route: GAVAGE                                                                                                     Time: 11:07:14

                                                         FINAL #1/MICE




       Facility:  Southern Research Institute

       Chemical CAS #:  142-83-6

       Lock Date:  02/24/00

       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: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                      6            4            5            6                                     
    Moribund Sacrifice                                 2            8            8            4                                     
    Dosing Accident                                                                           1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                42           37           37           37                                     
    Natural Death                                                                             2                                     
  Missing                                                           1                                                               
                                                                                                                                    
  Animals Examined Microscopically                    50           49           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (49)         (49)         (50)         (50)                                   
      Perforation                                                                             1 (2%)                                
      Epithelium, Hyperplasia, Squamous                1 (2%)                                                                       
      Periesophageal Tissue, Foreign Body                                                     1 (2%)                                
   Gallbladder                                        (44)         (45)         (47)         (41)                                   
      Cyst                                                          3 (7%)       1 (2%)       2 (5%)                                
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
   Liver                                              (50)         (49)         (50)         (50)                                   
      Angiectasis                                                   1 (2%)       2 (4%)                                             
      Basophilic Focus                                              2 (4%)                                                          
      Congestion, Focal                                             1 (2%)       1 (2%)       1 (2%)                                
      Fibrosis, Focal                                  1 (2%)                                                                       
      Hemorrhage, Focal                                                          1 (2%)       1 (2%)                                
      Hyperplasia, Focal, Lymphoid                     1 (2%)       1 (2%)                                                          
      Hyperplasia, Lymphoid                            2 (4%)                    1 (2%)                                             
      Infarct, Chronic                                                           1 (2%)                                             
      Infiltration Cellular, Mixed Cell               41 (82%)     35 (71%)     36 (72%)     31 (62%)                               
      Mineralization, Focal                                                      1 (2%)                                             
      Mixed Cell Focus                                                           2 (4%)                                             
      Mixed Cell Focus, Multiple                       1 (2%)                                                                       
      Tension Lipidosis                                                          1 (2%)                                             
      Bile Duct, Cyst                                  1 (2%)                                 1 (2%)                                
      Bile Duct, Hyperplasia                           1 (2%)                                 1 (2%)                                
      Bile Duct, Hyperplasia, Cystic                   1 (2%)                                                                       
      Hepatocyte, Basophilic Focus                     1 (2%)       2 (4%)                    1 (2%)                                
      Hepatocyte, Cytomegaly                                        1 (2%)                                                          
      Hepatocyte, Depletion Glycogen, Diffuse          2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatocyte, Eosinophilic Focus                                1 (2%)                    1 (2%)                                
      Hepatocyte, Karyomegaly                                       1 (2%)                                                          
      Hepatocyte, Mixed Cell Focus                                  1 (2%)       1 (2%)       1 (2%)                                
      Hepatocyte, Necrosis, Focal                      1 (2%)       3 (6%)                    2 (4%)                                
      Hepatocyte, Vacuolization Cytoplasmic,                                                                                        
          Diffuse                                      5 (10%)      2 (4%)       2 (4%)       5 (10%)                               
      Hepatocyte, Vacuolization Cytoplasmic, Focal     2 (4%)       1 (2%)                                                          
      Hepatocyte, Periportal, Depletion Glycogen                                 1 (2%)                                             
      Hepatocyte, Periportal, Vacuolization                                                                                         
          Cytoplasmic                                  8 (16%)      5 (10%)      3 (6%)       1 (2%)                                
      Hepatocyte, Centrilobular, Necrosis              1 (2%)                                 2 (4%)                                
      Hepatocyte, Centrilobular, Vacuolization                                                                                      
          Cytoplasmic                                                            2 (4%)       1 (2%)                                
      Hepatocyte, Midzonal, Vacuolization                                                                                           
          Cytoplasmic                                 12 (24%)      7 (14%)      3 (6%)       6 (12%)                               
      Oval Cell, Hyperplasia                           1 (2%)                                                                       
      Portal, Infiltration Cellular, Focal,                                                                                         
          Lymphocyte                                   1 (2%)                                                                       
      Serosa, Hyperplasia, Focal, Lymphoid                          1 (2%)                                                          
   Mesentery                                          (31)         (30)         (37)         (25)                                   
      Angiectasis                                      1 (3%)       2 (7%)                                                          
      Angiectasis, Focal                               1 (3%)                                 1 (4%)                                
      Congestion, Focal                                             1 (3%)                                                          
      Fibrosis, Focal                                               1 (3%)                                                          
      Hemorrhage                                                    1 (3%)       1 (3%)                                             
      Inflammation, Chronic                                                      1 (3%)                                             
      Artery, Mineralization                           2 (6%)                                                                       
      Fat, Necrosis                                   29 (94%)     28 (93%)     34 (92%)     22 (88%)                               
      Lymphatic, Angiectasis                                        1 (3%)       3 (8%)                                             
   Pancreas                                           (47)         (46)         (50)         (47)                                   
      Infiltration Cellular, Focal, Mixed Cell         1 (2%)                                                                       
      Necrosis, Focal                                                            1 (2%)                                             
      Acinus, Atrophy, Focal                                        1 (2%)                    1 (2%)                                
      Duct, Cyst                                       1 (2%)                    1 (2%)                                             
   Salivary Glands                                    (49)         (48)         (48)         (50)                                   
      Hyperplasia, Lymphoid                                                      2 (4%)                                             
      Submandibular Gland, Vacuolization                                                                                            
          Cytoplasmic                                               1 (2%)                                                          
   Stomach, Forestomach                               (48)         (48)         (50)         (48)                                   
      Diverticulum                                                                            1 (2%)                                
      Erosion                                                       1 (2%)       1 (2%)                                             
      Erosion, Focal                                                             1 (2%)                                             
      Inflammation, Focal                                           2 (4%)                    2 (4%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Ulcer                                            1 (2%)       1 (2%)       2 (4%)                                             
      Epithelium, Hyperplasia, Squamous                4 (8%)       8 (17%)     12 (24%)     31 (65%)                               
      Epithelium, Ulcer, Focal                                                                1 (2%)                                
   Stomach, Glandular                                 (45)         (45)         (48)         (46)                                   
      Glands, Degeneration, Cystic, Focal              1 (2%)                                 1 (2%)                                
      Muscularis, Mineralization                       1 (2%)                                                                       
   Tooth                                              (1)                                    (2)                                    
      Peridontal Tissue, Inflammation, Chronic                                                2 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (2)                       (1)                                                 
      Aorta, Mineralization                            2 (100%)                                                                     
      Pulmonary Artery, Mineralization                 2 (100%)                                                                     
      Pulmonary Vein, Mineralization                   2 (100%)                                                                     
   Heart                                              (49)         (49)         (50)         (50)                                   
      Infiltration Cellular, Mixed Cell                             1 (2%)                                                          
      Mineralization, Focal                            2 (4%)       1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (48)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule                             2 (4%)       2 (4%)       3 (6%)                                
      Angiectasis                                      1 (2%)       1 (2%)                                                          
      Cyst                                             2 (4%)                                                                       
      Cytoplasmic Alteration, Focal                    1 (2%)                                                                       
      Degeneration, Cystic, Focal                                   1 (2%)                                                          
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Subcapsular, Hyperplasia, Focal                                            1 (2%)                                             
   Adrenal Medulla                                    (50)         (48)         (49)         (49)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Parathyroid Gland                                  (45)         (46)         (49)         (47)                                   
      Cyst                                             1 (2%)       1 (2%)                    2 (4%)                                
      Cyst, Multiple                                                             1 (2%)                                             
      Hyperplasia, Cystic                                           1 (2%)                                                          
   Pituitary Gland                                    (46)         (48)         (47)         (50)                                   
      Angiectasis                                      3 (7%)       1 (2%)                    1 (2%)                                
      Pars Distalis, Angiectasis                                                              1 (2%)                                
      Pars Distalis, Cyst, Multiple                    1 (2%)                                                                       
      Pars Distalis, Cytoplasmic Alteration, Focal     6 (13%)      3 (6%)       2 (4%)       4 (8%)                                
      Pars Distalis, Degeneration, Cystic, Focal       2 (4%)       2 (4%)       4 (9%)       1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Distalis, Hemorrhage, Focal                              3 (6%)                    1 (2%)                                
      Pars Distalis, Hyperplasia                                                 1 (2%)                                             
      Pars Distalis, Hyperplasia, Focal                2 (4%)       5 (10%)      6 (13%)      2 (4%)                                
      Rathke's Cleft, Hyperplasia, Cystic                                                     1 (2%)                                
   Thyroid Gland                                      (49)         (46)         (49)         (50)                                   
      Atrophy, Focal                                                             1 (2%)                                             
      Degeneration, Cystic, Focal                      7 (14%)     14 (30%)      9 (18%)     11 (22%)                               
      Ectopic Thymus                                                             2 (4%)                                             
      Inflammation, Chronic                                                      1 (2%)                                             
      Inflammation, Chronic, Focal                                               1 (2%)                                             
      Follicle, Cyst                                   1 (2%)       1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (1)          (1)          (2)          (1)                                    
      Abdominal, Abscess                                            1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (47)         (45)         (45)         (50)                                   
      Angiectasis                                      1 (2%)                                                                       
      Degeneration, Cystic                                          2 (4%)       2 (4%)       1 (2%)                                
      Inflammation, Chronic                                                      1 (2%)                                             
   Ovary                                              (49)         (47)         (48)         (48)                                   
      Angiectasis                                                   1 (2%)       1 (2%)       1 (2%)                                
      Cyst                                            13 (27%)     11 (23%)     11 (23%)     10 (21%)                               
      Cyst, Multiple                                   1 (2%)                    1 (2%)                                             
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia, Cystic                              1 (2%)                                                                       
      Hyperplasia, Tubular                             1 (2%)                                                                       
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                                    1 (2%)       1 (2%)                                             
      Bilateral, Cyst                                  1 (2%)                                 1 (2%)                                
      Bilateral, Follicle, Cyst                                                               1 (2%)                                
      Bilateral, Follicle, Hemorrhage                                                         1 (2%)                                
      Periovarian Tissue, Mineralization                                                      1 (2%)                                
   Uterus                                             (50)         (49)         (50)         (50)                                   
      Angiectasis                                      1 (2%)                    1 (2%)       2 (4%)                                
      Congestion                                                    1 (2%)                                                          
      Cyst                                             1 (2%)       2 (4%)       1 (2%)                                             
      Cyst, Multiple                                                1 (2%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Edema                                            1 (2%)                                                                       
      Hemorrhage                                                    1 (2%)                                                          
      Hydrometra                                      33 (66%)     35 (71%)     40 (80%)     39 (78%)                               
      Inflammation, Chronic                                                                   1 (2%)                                
      Endometrium, Hyperplasia, Cystic                39 (78%)     39 (80%)     42 (84%)     40 (80%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (47)         (50)         (48)                                   
      Hyperplasia, Megakaryocyte                                                 1 (2%)                                             
      Myeloid Cell, Hyperplasia                        3 (6%)       5 (11%)      4 (8%)       5 (10%)                               
   Lymph Node                                         (8)          (9)          (9)          (7)                                    
      Iliac, Hyperplasia, Plasma Cell                  1 (13%)      1 (11%)                   1 (14%)                               
      Iliac, Pigmentation                              1 (13%)                                                                      
      Inguinal, Hyperplasia, Lymphoid                  1 (13%)                   2 (22%)                                            
      Inguinal, Hyperplasia, Plasma Cell               1 (13%)      1 (11%)                                                         
      Inguinal, Infiltration Cellular, Mixed Cell                                             1 (14%)                               
      Mediastinal, Hemorrhage                                                                 1 (14%)                               
      Mediastinal, Hyperplasia, Lymphoid               1 (13%)      2 (22%)      2 (22%)                                            
      Mediastinal, Hyperplasia, Plasma Cell            1 (13%)                                1 (14%)                               
      Renal, Hyperplasia, Plasma Cell                                                         1 (14%)                               
      Renal, Infiltration Cellular, Mixed Cell                                                1 (14%)                               
   Lymph Node, Mandibular                             (47)         (47)         (48)         (49)                                   
      Congestion                                                                 1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Hyperplasia, Plasma Cell                         1 (2%)                                                                       
   Lymph Node, Mesenteric                             (47)         (46)         (49)         (49)                                   
      Angiectasis                                                   2 (4%)                                                          
      Atypia Cellular                                               1 (2%)                                                          
      Hyperplasia, Cystic                                                                     1 (2%)                                
      Hyperplasia, Histiocytic                                      1 (2%)       2 (4%)                                             
      Hyperplasia, Lymphoid                                         1 (2%)       2 (4%)                                             
      Hyperplasia, Plasma Cell                         3 (6%)       2 (4%)                                                          
   Spleen                                             (48)         (47)         (50)         (49)                                   
      Accessory Spleen                                              1 (2%)                                                          
      Angiectasis                                                   1 (2%)                    1 (2%)                                
      Congestion                                       1 (2%)       3 (6%)                    2 (4%)                                
      Depletion Cellular                                                         2 (4%)                                             
      Hematopoietic Cell Proliferation                20 (42%)     29 (62%)     29 (58%)     17 (35%)                               
      Hemorrhage                                       1 (2%)       1 (2%)                    1 (2%)                                
      Hyperplasia, Histiocytic                         1 (2%)                                                                       
      Hyperplasia, Lymphoid                            8 (17%)      9 (19%)      7 (14%)      7 (14%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Necrosis, Focal                                  1 (2%)       2 (4%)                                                          
      Pigmentation, Focal                                                        1 (2%)                                             
      Thrombosis                                                                              1 (2%)                                
   Thymus                                             (44)         (46)         (48)         (46)                                   
      Atrophy                                                                    1 (2%)                                             
      Cyst                                                                       1 (2%)       3 (7%)                                
      Hemorrhage                                       1 (2%)                                                                       
      Hyperplasia, Lymphoid                                         1 (2%)       1 (2%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (48)         (49)         (50)         (50)                                   
      Ectasia                                          2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
      Hyperplasia                                      2 (4%)                    3 (6%)                                             
      Metaplasia, Focal, Squamous                                   1 (2%)                                                          
   Skin                                               (50)         (49)         (50)         (50)                                   
      Ulcer                                            1 (2%)                                                                       
      Hair Follicle, Atrophy, Focal                    1 (2%)                                                                       
      Subcutaneous Tissue, Fibrosis, Focal             1 (2%)                                                                       
      Subcutaneous Tissue, Hemorrhage, Focal                        1 (2%)                    1 (2%)                                
      Subcutaneous Tissue, Infiltration Cellular,                                                                                   
           Focal, Mixed Cell                                        1 (2%)                                                          
      Subcutaneous Tissue, Inflammation, Chronic                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                    (6)          (4)          (5)          (2)                                    
      Fibrosis                                                                   1 (20%)                                            
      Inflammation, Chronic                            1 (17%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (48)         (50)         (50)                                   
      Compression, Focal                               2 (4%)       3 (6%)       2 (4%)       1 (2%)                                
      Hemorrhage, Focal                                                          1 (2%)       1 (2%)                                
      Ventricle, Hydrocephalus                         1 (2%)                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
   Lung                                               (49)         (49)         (50)         (50)                                   
      Congestion                                       1 (2%)       2 (4%)       2 (4%)       2 (4%)                                
      Fibrosis, Focal                                  1 (2%)                                                                       
      Hemorrhage                                       1 (2%)       2 (4%)       2 (4%)                                             
      Hemorrhage, Focal                                                                       1 (2%)                                
      Hyperplasia, Histiocytic                         2 (4%)                    1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)       3 (6%)       2 (4%)                                             
      Infiltration Cellular, Focal, Mixed Cell                                                1 (2%)                                
      Infiltration Cellular, Mixed Cell                             1 (2%)                                                          
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                       1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                                                        1 (2%)                                
      Artery, Mineralization                           1 (2%)                                                                       
      Vein, Mineralization                             1 (2%)                                                                       
   Nose                                               (50)         (48)         (50)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Inflammation, Suppurative                       18 (36%)     22 (46%)     23 (46%)     16 (32%)                               
      Mucosa, Glands, Dilatation, Focal                5 (10%)                   2 (4%)       6 (12%)                               
      Nasolacrimal Duct, Cyst                                                    1 (2%)                                             
      Nasolacrimal Duct, Inflammation                  1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Nasolacrimal Duct, Mineralization                1 (2%)                                                                       
      Olfactory Epithelium, Cytoplasmic Alteration    28 (56%)     23 (48%)     34 (68%)     28 (56%)                               
      Respiratory Epithelium, Cytoplasmic                                                                                           
          Alteration                                  50 (100%)    47 (98%)     49 (98%)     48 (96%)                               
      Respiratory Epithelium, Necrosis                              1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (2)          (3)          (2)          (2)                                    
      Atrophy                                                       2 (67%)      2 (100%)                                           
      Cornea, Hyperplasia, Focal, Squamous             1 (50%)      1 (33%)                                                         
      Cornea, Inflammation, Focal                      1 (50%)      1 (33%)                                                         
   Harderian Gland                                    (8)          (6)          (4)          (1)                                    
      Hyperplasia, Focal                               1 (13%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (47)         (49)         (48)                                   
      Atrophy                                                                                 1 (2%)                                
      Congestion                                                    1 (2%)       1 (2%)                                             
      Cyst                                             3 (6%)       4 (9%)       1 (2%)       1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Cyst, Multiple                                                             1 (2%)                                             
      Hydronephrosis                                                                          1 (2%)                                
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Infarct                                          3 (6%)       1 (2%)       5 (10%)      4 (8%)                                
      Infarct, Focal                                   1 (2%)                                                                       
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
      Metaplasia, Focal, Osseous                       2 (4%)       1 (2%)                    1 (2%)                                
      Nephropathy                                     19 (38%)     15 (32%)     17 (35%)     22 (46%)                               
      Artery, Mineralization                           2 (4%)                                                                       
      Papilla, Mineralization, Focal                                             1 (2%)                                             
      Papilla, Necrosis                                                          4 (8%)       1 (2%)                                
      Renal Tubule, Accumulation, Hyaline Droplet      3 (6%)                    2 (4%)       1 (2%)                                
      Renal Tubule, Accumulation, Hyaline Droplet,                                                                                  
           Focal                                                                              1 (2%)                                
      Renal Tubule, Necrosis                                                     1 (2%)                                             
      Renal Tubule, Pigmentation                                    1 (2%)                    2 (4%)                                
   Urinary Bladder                                    (48)         (47)         (48)         (48)                                   
      Transitional Epithelium, Hyperplasia             1 (2%)                                                                       
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 3            3            3            8                                     
    Natural Death                                      3            8            3            3                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                44           39           44           38                                     
    Natural Death                                                                             1                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (48)         (47)         (45)         (46)                                   
      Cyst                                             2 (4%)                    2 (4%)       1 (2%)                                
      Cyst, Multiple                                   1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Polymorphonuclear                      1 (2%)                                                          
      Epithelium, Degeneration, Hyaline                             1 (2%)       2 (4%)                                             
      Epithelium, Hyperplasia, Adenomatous                          1 (2%)       1 (2%)                                             
   Intestine Large, Cecum                             (47)         (45)         (48)         (48)                                   
      Serosa, Fibrosis, Focal                          1 (2%)                                                                       
   Intestine Small, Duodenum                          (47)         (47)         (48)         (49)                                   
      Epithelium, Cyst                                 1 (2%)                                                                       
   Intestine Small, Jejunum                           (47)         (45)         (49)         (48)                                   
      Inflammation, Chronic Active                                                            1 (2%)                                
      Peyer's Patch, Hyperplasia, Histiocytic                       1 (2%)                                                          
      Peyer's Patch, Hyperplasia, Lymphoid                                       1 (2%)                                             
   Intestine Small, Ileum                             (47)         (45)         (47)         (48)                                   
      Infiltration Cellular, Mixed Cell                                          1 (2%)                                             
      Serosa, Fibrosis, Focal                          1 (2%)                                                                       
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      2 (4%)                                                                       
      Angiectasis, Focal                                            1 (2%)                                                          
      Clear Cell Focus                                                                        1 (2%)                                
      Congestion                                       1 (2%)                                                                       
      Congestion, Focal                                1 (2%)       3 (6%)       1 (2%)       3 (6%)                                
      Eosinophilic Focus                                                                      1 (2%)                                
      Eosinophilic Focus, Multiple                                  1 (2%)                                                          
      Erythrophagocytosis                                                        1 (2%)                                             
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hemorrhage, Focal                                             2 (4%)       1 (2%)       2 (4%)                                
      Hyperplasia, Focal, Histiocytic                                            1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hyperplasia, Focal, Lymphoid                                               1 (2%)                                             
      Hyperplasia, Histiocytic                                      1 (2%)                                                          
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
      Infarct                                          2 (4%)                                                                       
      Infiltration Cellular, Lymphocyte                                          1 (2%)                                             
      Infiltration Cellular, Mixed Cell               31 (62%)     27 (54%)     30 (60%)     31 (62%)                               
      Inflammation, Chronic                                                      1 (2%)       1 (2%)                                
      Mixed Cell Focus                                 1 (2%)       1 (2%)                    3 (6%)                                
      Necrosis, Focal                                               2 (4%)       1 (2%)                                             
      Pigmentation, Focal                                                        1 (2%)                                             
      Bile Duct, Hyperplasia                                                                  1 (2%)                                
      Hepatocyte, Basophilic Focus                                  2 (4%)       1 (2%)       1 (2%)                                
      Hepatocyte, Cytomegaly                           2 (4%)       2 (4%)                    2 (4%)                                
      Hepatocyte, Eosinophilic Focus                   3 (6%)       5 (10%)      2 (4%)       4 (8%)                                
      Hepatocyte, Eosinophilic Focus, Multiple                                   1 (2%)                                             
      Hepatocyte, Karyomegaly                          2 (4%)                                 2 (4%)                                
      Hepatocyte, Mixed Cell Focus                     1 (2%)       6 (12%)      9 (18%)      5 (10%)                               
      Hepatocyte, Mixed Cell Focus, Multiple           1 (2%)       3 (6%)                    3 (6%)                                
      Hepatocyte, Necrosis, Focal                      1 (2%)       1 (2%)       2 (4%)       2 (4%)                                
      Hepatocyte, Vacuolization Cytoplasmic,                                                                                        
          Diffuse                                      6 (12%)      1 (2%)       1 (2%)       4 (8%)                                
      Hepatocyte, Vacuolization Cytoplasmic, Focal    13 (26%)     15 (30%)     16 (32%)     12 (24%)                               
      Hepatocyte, Periportal, Vacuolization                                                                                         
          Cytoplasmic                                  3 (6%)       3 (6%)       2 (4%)       2 (4%)                                
      Hepatocyte, Centrilobular, Depletion Glycogen                 1 (2%)                                                          
      Hepatocyte, Centrilobular, Necrosis                           1 (2%)                                                          
      Hepatocyte, Midzonal, Vacuolization                                                                                           
          Cytoplasmic                                 17 (34%)      9 (18%)     20 (40%)     10 (20%)                               
      Oval Cell, Hyperplasia                                                     1 (2%)       1 (2%)                                
   Mesentery                                          (25)         (28)         (33)         (32)                                   
      Fibrosis, Focal                                  1 (4%)                    1 (3%)                                             
      Hemorrhage                                                    1 (4%)       1 (3%)       1 (3%)                                
      Hemorrhage, Focal                                1 (4%)                                                                       
      Inflammation, Chronic                            1 (4%)       4 (14%)                   2 (6%)                                
      Fat, Necrosis                                   24 (96%)     27 (96%)     32 (97%)     31 (97%)                               
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Necrosis, Focal                                               1 (2%)                    1 (2%)                                
      Acinus, Atrophy, Diffuse                                                                1 (2%)                                
      Acinus, Atrophy, Focal                           1 (2%)       1 (2%)                    1 (2%)                                
      Acinus, Cytoplasmic Alteration                                1 (2%)                                                          
      Duct, Cyst                                                                 1 (2%)       1 (2%)                                
      Duct, Inflammation, Chronic, Focal                                                      1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (48)         (50)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Focal                              3 (6%)       1 (2%)       3 (6%)       6 (12%)                               
      Ulcer                                            2 (4%)                    3 (6%)      10 (20%)                               
      Ulcer, Focal                                                                            1 (2%)                                
      Epithelium, Cyst                                                                        1 (2%)                                
      Epithelium, Hyperplasia, Squamous               14 (28%)      7 (14%)      9 (19%)     26 (52%)                               
   Stomach, Glandular                                 (50)         (48)         (48)         (50)                                   
      Erosion                                                                                 1 (2%)                                
      Hyperplasia                                                                             1 (2%)                                
      Mineralization                                   1 (2%)                                                                       
      Glands, Degeneration, Cystic, Focal                                                     3 (6%)                                
   Tooth                                              (19)         (21)         (16)         (19)                                   
      Malformation                                    11 (58%)     13 (62%)     10 (63%)     12 (63%)                               
      Peridontal Tissue, Inflammation, Chronic        10 (53%)      9 (43%)      8 (50%)     10 (53%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Infiltration Cellular, Mixed Cell                                                       2 (4%)                                
      Inflammation, Chronic, Focal                     1 (2%)                                 2 (4%)                                
      Mineralization, Focal                                         1 (2%)                                                          
      Valve, Hemorrhage, Focal                                                                1 (2%)                                
      Valve, Inflammation, Chronic, Focal                                                     1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule                1 (2%)                    1 (2%)       5 (10%)                               
      Cytoplasmic Alteration, Focal                    7 (14%)      2 (4%)       3 (6%)       5 (10%)                               
      Hypertrophy, Focal                               1 (2%)                    1 (2%)                                             
      Bilateral, Accessory Adrenal Cortical Nodule                                            1 (2%)                                
      Subcapsular, Hyperplasia, Focal                 11 (22%)      7 (14%)      8 (16%)      7 (14%)                               
   Adrenal Medulla                                    (49)         (50)         (50)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Hyperplasia                                      1 (2%)                    1 (2%)       1 (2%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Hyperplasia                                                   1 (2%)       1 (2%)       2 (4%)                                
   Parathyroid Gland                                  (47)         (48)         (49)         (46)                                   
      Cyst                                             1 (2%)                    2 (4%)       1 (2%)                                
   Pituitary Gland                                    (48)         (47)         (48)         (49)                                   
      Pars Distalis, Cyst                              3 (6%)       2 (4%)       3 (6%)       3 (6%)                                
      Pars Distalis, Cyst, Multiple                                              1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Distalis, Cytoplasmic Alteration, Focal                                            1 (2%)                                
      Pars Distalis, Degeneration, Cystic, Focal                                 1 (2%)                                             
      Pars Distalis, Hyperplasia, Focal                             2 (4%)       1 (2%)                                             
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Degeneration, Cystic, Focal                      7 (14%)      5 (10%)      5 (10%)      6 (12%)                               
      Follicle, Cyst                                   1 (2%)       1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                                      (1)                                                              
      Inflammation, Focal                                           1 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                  (1)          (2)          (1)          (1)                                    
      Inflammation, Chronic                                                                   1 (100%)                              
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Inflammation, Chronic                            1 (2%)       1 (2%)                                                          
      Bilateral, Hemorrhage                            1 (2%)                                                                       
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Degeneration, Cystic                            16 (32%)     17 (34%)      9 (18%)     21 (42%)                               
      Inflammation, Chronic                            1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Metaplasia, Squamous                                                                    1 (2%)                                
   Prostate                                           (49)         (50)         (50)         (50)                                   
      Inflammation, Chronic                            1 (2%)                                 1 (2%)                                
      Epithelium, Hyperplasia, Focal                                                          1 (2%)                                
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Dilatation                                       1 (2%)                    2 (4%)                                             
      Inflammation, Chronic                                         1 (2%)       2 (4%)       1 (2%)                                
      Bilateral, Dilatation                                                      1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Hemorrhage                                       1 (2%)                                                                       
      Mineralization                                                                          1 (2%)                                
      Interstitial Cell, Hyperplasia                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Fibrosis, Focal                                               1 (2%)                                                          
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   13                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Thrombosis, Chronic                                           1 (2%)                                                          
      Myeloid Cell, Hyperplasia                        1 (2%)       1 (2%)       2 (4%)       3 (6%)                                
   Lymph Node                                         (1)          (4)          (2)          (7)                                    
      Inguinal, Hyperplasia, Lymphoid                               1 (25%)                                                         
      Inguinal, Hyperplasia, Plasma Cell                                                      1 (14%)                               
      Mediastinal, Congestion                                       1 (25%)                                                         
      Mediastinal, Hyperplasia, Lymphoid               1 (100%)                                                                     
      Mediastinal, Hyperplasia, Plasma Cell                                      1 (50%)      3 (43%)                               
      Mediastinal, Infiltration Cellular, Mixed                                                                                     
          Cell                                                                                1 (14%)                               
   Lymph Node, Mandibular                             (48)         (48)         (49)         (49)                                   
      Hyperplasia, Histiocytic                         1 (2%)                                                                       
      Hyperplasia, Lymphoid                            1 (2%)       3 (6%)       1 (2%)       1 (2%)                                
      Hyperplasia, Plasma Cell                         2 (4%)       1 (2%)       1 (2%)       3 (6%)                                
      Pigmentation                                                               1 (2%)                                             
   Lymph Node, Mesenteric                             (50)         (49)         (47)         (50)                                   
      Congestion                                                                              1 (2%)                                
      Hemorrhage                                       1 (2%)                    2 (4%)                                             
      Hyperplasia, Histiocytic                                      1 (2%)                                                          
      Hyperplasia, Lymphoid                                         1 (2%)                                                          
      Hyperplasia, Plasma Cell                         6 (12%)                   2 (4%)       2 (4%)                                
      Infiltration Cellular, Polymorphonuclear         1 (2%)                                                                       
   Spleen                                             (49)         (50)         (50)         (49)                                   
      Depletion Cellular                                            1 (2%)                    1 (2%)                                
      Hematopoietic Cell Proliferation                14 (29%)     18 (36%)     18 (36%)     23 (47%)                               
      Hyperplasia, Histiocytic                                      1 (2%)                                                          
      Hyperplasia, Lymphoid                            3 (6%)       3 (6%)       2 (4%)                                             
   Thymus                                             (44)         (46)         (47)         (42)                                   
      Angiectasis                                      1 (2%)       1 (2%)                                                          
      Atrophy                                          1 (2%)       1 (2%)       1 (2%)                                             
      Cyst                                            10 (23%)      9 (20%)      5 (11%)      9 (21%)                               
      Cyst, Multiple                                                             2 (4%)                                             
      Hyperplasia, Lymphoid                                         1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Hyperkeratosis, Focal                                                                   1 (2%)                                
      Inflammation, Chronic, Focal                                               1 (2%)       1 (2%)                                
      Ulcer                                                                      2 (4%)                                             
      Epidermis, Hyperplasia, Focal                                                           1 (2%)                                
      Subcutaneous Tissue, Congestion, Focal           1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   14                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - CONT                                                                                                         
      Subcutaneous Tissue, Necrosis, Fatty, Focal                                1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Cranium, Hyperostosis                            1 (2%)                                                                       
   Skeletal Muscle                                    (1)                       (2)          (3)                                    
      Infiltration Cellular, Focal, Lipocyte           1 (100%)                  1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression, Focal                                            1 (2%)                                                          
      Hemorrhage, Focal                                                          1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       1 (2%)                    3 (6%)       1 (2%)                                
      Hemorrhage                                                    1 (2%)       2 (4%)       1 (2%)                                
      Hyperplasia, Histiocytic                         5 (10%)      3 (6%)       6 (12%)      6 (12%)                               
      Hyperplasia, Lymphoid                                         2 (4%)       2 (4%)       1 (2%)                                
      Infiltration Cellular, Eosinophil, Focal                                                1 (2%)                                
      Infiltration Cellular, Focal, Mixed Cell                      1 (2%)                                                          
      Infiltration Cellular, Mixed Cell                             2 (4%)       2 (4%)       1 (2%)                                
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
      Metaplasia, Focal, Osseous                                    1 (2%)                                                          
      Pigmentation, Focal                                           1 (2%)                                                          
      Alveolar Epithelium, Hyperplasia                 5 (10%)      6 (12%)      4 (8%)                                             
      Alveolar Epithelium, Hyperplasia, Focal                                                 1 (2%)                                
      Mediastinum, Necrosis, Fatty, Focal                           1 (2%)                                                          
   Nose                                               (50)         (50)         (48)         (50)                                   
      Foreign Body                                                  1 (2%)                                                          
      Inflammation, Suppurative                        7 (14%)     11 (22%)     13 (27%)     13 (26%)                               
      Mineralization, Focal                                                                   1 (2%)                                
      Polyp, Inflammatory                                                        2 (4%)                                             
      Glands, Cytoplasmic Alteration                   1 (2%)                                                                       
      Mucosa, Glands, Dilatation, Focal                4 (8%)       2 (4%)                    6 (12%)                               
      Nasolacrimal Duct, Inflammation                  2 (4%)       2 (4%)                    1 (2%)                                
      Olfactory Epithelium, Cytoplasmic Alteration    24 (48%)     19 (38%)     17 (35%)     19 (38%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   15                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Respiratory Epithelium, Cytoplasmic                                                                                           
          Alteration                                  48 (96%)     47 (94%)     45 (94%)     45 (90%)                               
      Respiratory Epithelium, Metaplasia, Squamous                               1 (2%)                                             
      Sinus, Glands, Fibrosis, Focal                                             1 (2%)                                             
      Vomeronasal Organ, Cyst                                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)          (3)                       (3)                                    
      Atrophy                                                       1 (33%)                                                         
      Cornea, Hyperplasia, Focal, Squamous                          1 (33%)                   3 (100%)                              
      Cornea, Inflammation, Chronic                                 2 (67%)                                                         
      Cornea, Inflammation, Focal                                   1 (33%)                   3 (100%)                              
      Cornea, Necrosis, Focal                                                                 2 (67%)                               
      Iris, Synechia                                                1 (33%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (48)         (50)         (50)                                   
      Accumulation, Hyaline Droplet                                              1 (2%)                                             
      Atrophy                                                                    1 (2%)                                             
      Atrophy, Focal                                   1 (2%)       2 (4%)       1 (2%)                                             
      Congestion                                       2 (4%)       1 (2%)       1 (2%)                                             
      Cyst                                             7 (14%)     11 (23%)      4 (8%)       5 (10%)                               
      Cyst, Multiple                                                1 (2%)       1 (2%)       1 (2%)                                
      Hydronephrosis                                                             1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Focal, Mixed Cell                                                1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                                 1 (2%)                                
      Metaplasia, Focal, Osseous                       3 (6%)       1 (2%)       1 (2%)                                             
      Nephropathy                                     47 (94%)     44 (92%)     48 (96%)     46 (92%)                               
      Papilla, Necrosis                                             1 (2%)                                                          
      Renal Tubule, Accumulation, Hyaline Droplet                                             1 (2%)                                
      Renal Tubule, Dilatation, Focal                  1 (2%)                                                                       
      Renal Tubule, Hyperplasia, Focal                 1 (2%)       2 (4%)       2 (4%)       4 (8%)                                
      Renal Tubule, Pigmentation                       1 (2%)       1 (2%)                                                          
   Urethra                                            (1)                       (1)                                                 
      Inflammation                                     1 (100%)                                                                     
      Necrosis, Focal                                  1 (100%)                                                                     
   Urinary Bladder                                    (50)         (49)         (49)         (50)                                   
      Inflammation, Suppurative                        1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   16                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 02/15/01    
Route: GAVAGE                                                                                                     Time: 11:07:14    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          0            30           60           120                                       
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Transitional Epithelium, Hyperplasia                                                    1 (2%)                                
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   17                                                              
                                                                                                                                   
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