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TDMS Study 05180-07 Pathology Tables

NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25

                                                      2 YEAR CHRONIC MICE




       Facility:  Battelle Northwest

       Chemical CAS #:  1303-00-0000

       Lock Date:  04/11/97

       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: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 


  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                11           11           16           11                                     
    Natural Death                                      3            3            2           10                                     
    Accidently Killed                                               2            1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                36           34           31           29                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (50)         (49)         (50)                                   
      Inflammation, Suppurative                                     1 (2%)                                                          
   Gallbladder                                        (47)         (45)         (45)         (41)                                   
      Degeneration, Hyaline                                         1 (2%)                                                          
      Epithelium, Hyperplasia                          1 (2%)                                                                       
   Intestine Large, Cecum                             (48)         (49)         (50)         (46)                                   
      Hemorrhage                                                    1 (2%)                                                          
      Infiltration Cellular, Mast Cell                                           1 (2%)                                             
   Intestine Small, Jejunum                           (48)         (47)         (49)         (43)                                   
      Peyer's Patch, Hyperplasia                       2 (4%)       1 (2%)                                                          
   Intestine Small, Ileum                             (48)         (47)         (49)         (45)                                   
      Hemorrhage                                                    1 (2%)                                                          
      Inflammation                                                  1 (2%)       1 (2%)                                             
      Peyer's Patch, Hyperplasia                       1 (2%)                    2 (4%)       1 (2%)                                
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                                                             1 (2%)                                
      Clear Cell Focus                                                           1 (2%)                                             
      Clear Cell Focus, Multiple                       1 (2%)                                                                       
      Degeneration, Fatty                              1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Eosinophilic Focus                               3 (6%)      13 (26%)     10 (20%)     10 (20%)                               
      Eosinophilic Focus, Multiple                     2 (4%)       2 (4%)       1 (2%)       4 (8%)                                
      Hematopoietic Cell Proliferation                 3 (6%)       4 (8%)       5 (10%)      5 (10%)                               
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)       3 (6%)       1 (2%)                                             
      Inflammation                                     3 (6%)       1 (2%)       1 (2%)                                             
      Necrosis                                         3 (6%)       4 (8%)       7 (14%)      5 (10%)                               
      Pigmentation, Hemosiderin                        1 (2%)                                                                       
      Bile Duct, Cyst                                  1 (2%)                                                                       
      Bile Duct, Degeneration, Hyaline                 1 (2%)                                                                       
      Oval Cell, Hyperplasia                           1 (2%)       1 (2%)                                                          
      Serosa, Inflammation                                                                    1 (2%)                                
   Mesentery                                          (8)          (9)          (16)         (13)                                   
      Hemorrhage                                       1 (13%)                                1 (8%)                                

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Chronic                            1 (13%)                                1 (8%)                                
      Inflammation, Suppurative                                                  2 (13%)                                            
      Fat, Necrosis                                    4 (50%)      9 (100%)    13 (81%)     11 (85%)                               
   Pancreas                                           (50)         (50)         (50)         (49)                                   
      Atrophy                                          5 (10%)     10 (20%)     11 (22%)      2 (4%)                                
      Cytoplasmic Alteration                           1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Duct, Cyst                                                    2 (4%)       2 (4%)                                             
   Stomach, Forestomach                               (49)         (50)         (50)         (49)                                   
      Hemorrhage                                       1 (2%)                                                                       
      Ulcer                                            1 (2%)       1 (2%)                    2 (4%)                                
      Epithelium, Hyperplasia                          2 (4%)       6 (12%)      1 (2%)       2 (4%)                                
   Stomach, Glandular                                 (49)         (50)         (50)         (48)                                   
      Inflammation, Suppurative                                     2 (4%)                                                          
      Ulcer                                                         1 (2%)       1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  49 (98%)     48 (96%)     47 (94%)     47 (94%)                               
      Artery, Inflammation                                          1 (2%)       1 (2%)       1 (2%)                                
      Atrium, Thrombosis                                                                      1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (49)                                   
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)                                             
      Hypertrophy                                      5 (10%)      5 (10%)      7 (14%)      7 (14%)                               
      Capsule, Hyperplasia                                                                    1 (2%)                                
   Adrenal Medulla                                    (50)         (49)         (50)         (49)                                   
      Hyperplasia                                      1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (48)                                   
      Hyperplasia                                      1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
   Pituitary Gland                                    (46)         (48)         (50)         (47)                                   
      Pars Distalis, Hyperplasia                      16 (35%)     20 (42%)     20 (40%)      9 (19%)                               
   Thyroid Gland                                      (50)         (50)         (50)         (49)                                   
      Follicular Cell, Hyperplasia                    10 (20%)     17 (34%)     14 (28%)     12 (24%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (49)         (50)         (50)         (46)                                   
      Angiectasis                                      2 (4%)                    2 (4%)                                             
      Atrophy                                          3 (6%)       2 (4%)       2 (4%)                                             
      Cyst                                            18 (37%)     17 (34%)     23 (46%)     15 (33%)                               
      Hemorrhage                                                                 1 (2%)                                             
      Hyperplasia                                                   1 (2%)                                                          
      Interstitial Stromal Tumor                       1 (2%)                                                                       
      Thrombosis                                                                 1 (2%)                                             
      Germinal Epithelium, Hyperplasia                              1 (2%)                                                          
   Uterus                                             (49)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)       1 (2%)       2 (4%)                                             
      Hematocyst                                       1 (2%)                                                                       
      Hydrometra                                       2 (4%)       4 (8%)       3 (6%)       4 (8%)                                
      Hyperplasia, Cystic                              2 (4%)       2 (4%)       2 (4%)       3 (6%)                                
      Inflammation, Suppurative                                     1 (2%)       1 (2%)                                             
      Thrombosis                                                                              1 (2%)                                
      Endometrium, Hyperplasia                         1 (2%)                                                                       
      Myometrium, Hyperplasia                          2 (4%)                    2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
   Lymph Node                                         (4)          (8)          (5)          (6)                                    
      Angiectasis                                      2 (50%)      1 (13%)      2 (40%)                                            
      Renal, Angiectasis                                            1 (13%)                                                         
      Renal, Hyperplasia                                            1 (13%)                   1 (17%)                               
   Lymph Node, Bronchial                              (39)         (43)         (42)         (42)                                   
      Hyperplasia                                     10 (26%)     12 (28%)     13 (31%)     23 (55%)                               
   Lymph Node, Mandibular                             (35)         (37)         (43)         (43)                                   
      Hyperplasia                                      1 (3%)                    1 (2%)       2 (5%)                                
   Lymph Node, Mesenteric                             (49)         (49)         (50)         (47)                                   
      Hyperplasia                                      3 (6%)       3 (6%)       5 (10%)      6 (13%)                               
   Lymph Node, Mediastinal                            (40)         (43)         (49)         (45)                                   
      Hematopoietic Cell Proliferation                                           2 (4%)                                             
      Hyperplasia                                      5 (13%)      3 (7%)       6 (12%)      8 (18%)                               
   Spleen                                             (50)         (50)         (50)         (49)                                   
      Hematopoietic Cell Proliferation                23 (46%)     22 (44%)     22 (44%)     28 (57%)                               
      Hyperplasia, Histiocytic                                                                1 (2%)                                
      Hyperplasia, Lymphoid                           20 (40%)     12 (24%)     18 (36%)      7 (14%)                               
      Capsule, Inflammation                            1 (2%)                                                                       
   Thymus                                             (43)         (47)         (43)         (44)                                   
      Angiectasis                                                                1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (49)                                   
      Hyperplasia                                      4 (8%)       4 (8%)       2 (4%)       3 (6%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Subcutaneous Tissue, Hemorrhage                               2 (4%)       2 (4%)                                             
      Subcutaneous Tissue, Inflammation                             1 (2%)       1 (2%)                                             
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                                                       1 (2%)                                
      Subcutaneous Tissue, Mineralization              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fibrous Osteodystrophy                          21 (42%)     24 (48%)     14 (28%)     18 (36%)                               
      Maxilla, Fracture                                             1 (2%)       1 (2%)                                             
   Skeletal Muscle                                    (1)          (2)          (1)          (1)                                    
      Hemorrhage                                                    1 (50%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                                               1 (2%)                                
      Gliosis                                                                    1 (2%)                                             
      Hemorrhage                                                    1 (2%)                    1 (2%)                                
      Meninges, Infiltration Cellular, Mononuclear                                                                                  
          Cell                                         2 (4%)       5 (10%)      3 (6%)       3 (6%)                                
   Spinal Cord                                        (1)          (1)          (1)                                                 
      Hyperplasia, Lymphoid                            1 (100%)                  1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                        2 (4%)       2 (4%)       2 (4%)       1 (2%)                                
      Squamous Epithelium, Hyperplasia                11 (22%)      9 (18%)      7 (14%)      7 (14%)                               
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       1 (2%)                                                                       
      Hemorrhage                                       9 (18%)      6 (12%)      5 (10%)      5 (10%)                               
      Infiltration Cellular, Histiocyte                2 (4%)      13 (26%)     48 (96%)     49 (98%)                               
      Inflammation, Chronic, Focal                     1 (2%)       2 (4%)      11 (22%)     18 (36%)                               
      Inflammation, Focal, Suppurative                                           2 (4%)      14 (28%)                               
      Alveolar Epithelium, Hyperplasia                 2 (4%)       5 (10%)     27 (54%)     43 (86%)                               
      Alveolus, Foreign Body                                        8 (16%)     48 (96%)     49 (98%)                               
      Alveolus, Proteinosis                                         4 (8%)      49 (98%)     50 (100%)                              

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Mediastinum, Necrosis                                         1 (2%)                                                          
      Perivascular, Infiltration Cellular,                                                                                          
          Mononuclear Cell                             2 (4%)                    2 (4%)       2 (4%)                                
   Nose                                               (50)         (49)         (50)         (50)                                   
      Inflammation, Suppurative                        2 (4%)                    4 (8%)       4 (8%)                                
      Olfactory Epithelium, Atrophy                    3 (6%)       1 (2%)       7 (14%)      4 (8%)                                
      Olfactory Epithelium, Degeneration, Hyaline      3 (6%)       1 (2%)      10 (20%)      5 (10%)                               
      Olfactory Epithelium, Inflammation, Chronic                                1 (2%)                                             
      Olfactory Epithelium, Metaplasia, Respiratory                              1 (2%)       1 (2%)                                
      Respiratory Epithelium, Degeneration, Hyaline   15 (30%)     17 (35%)     21 (42%)     17 (34%)                               
      Respiratory Epithelium, Metaplasia, Squamous                               2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                       (2)          (1)                                    
      Degeneration                                                               1 (50%)                                            
      Cornea, Inflammation, Chronic                    1 (100%)                  1 (50%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Glomerulosclerosis                               2 (4%)                                                                       
      Hydronephrosis                                   1 (2%)                                                                       
      Inflammation, Chronic Active                                                            1 (2%)                                
      Metaplasia, Osseous                              2 (4%)       3 (6%)       1 (2%)       1 (2%)                                
      Nephropathy                                     43 (86%)     44 (88%)     40 (80%)     36 (72%)                               
      Capsule, Inflammation                                                                   1 (2%)                                
      Renal Tubule, Hyperplasia                                                               1 (2%)                                
   Urinary Bladder                                    (48)         (48)         (50)         (48)                                   
      Angiectasis                                      1 (2%)                                                                       
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Artery, Inflammation                                                       1 (2%)                                             
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 


  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 7            8           10            7                                     
    Natural Death                                      8            4            6            9                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           38           34           34                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (42)         (47)         (41)         (43)                                   
      Degeneration, Hyaline                                         1 (2%)                    1 (2%)                                
   Intestine Small, Jejunum                           (44)         (48)         (45)         (43)                                   
      Peyer's Patch, Hyperplasia                       1 (2%)                    1 (2%)       1 (2%)                                
   Intestine Small, Ileum                             (44)         (47)         (45)         (42)                                   
      Peyer's Patch, Hyperplasia                                                 1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (50)                                   
      Basophilic Focus                                              1 (2%)       2 (4%)       2 (4%)                                
      Clear Cell Focus                                              2 (4%)       2 (4%)       1 (2%)                                
      Degeneration, Fatty                              1 (2%)       1 (2%)       1 (2%)                                             
      Eosinophilic Focus                               8 (16%)     12 (24%)     11 (22%)     14 (28%)                               
      Eosinophilic Focus, Multiple                     3 (6%)       2 (4%)       3 (6%)       5 (10%)                               
      Hematopoietic Cell Proliferation                 3 (6%)       1 (2%)       2 (4%)       2 (4%)                                
      Inflammation                                     2 (4%)       3 (6%)       1 (2%)                                             
      Necrosis                                        10 (20%)      6 (12%)      5 (10%)      4 (8%)                                
      Bile Duct, Cyst                                  1 (2%)                    1 (2%)                                             
      Oval Cell, Hyperplasia                           1 (2%)       1 (2%)                                                          
   Mesentery                                          (4)          (5)          (4)          (6)                                    
      Fat, Necrosis                                    1 (25%)      5 (100%)     3 (75%)      6 (100%)                              
   Pancreas                                           (50)         (50)         (49)         (47)                                   
      Atrophy                                         13 (26%)      7 (14%)      9 (18%)      6 (13%)                               
      Inflammation                                     1 (2%)                                                                       
   Stomach, Forestomach                               (50)         (50)         (49)         (49)                                   
      Ulcer                                            2 (4%)                                 1 (2%)                                
      Epithelium, Hyperplasia                          6 (12%)      2 (4%)       3 (6%)       3 (6%)                                
   Stomach, Glandular                                 (49)         (50)         (49)         (48)                                   
      Infiltration Cellular, Mixed Cell                             1 (2%)                                                          
      Ulcer                                                                                   1 (2%)                                
   Tooth                                              (1)          (3)          (1)          (1)                                    
      Malformation                                     1 (100%)     2 (67%)      1 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  48 (96%)     50 (100%)    49 (98%)     47 (94%)                               
      Thrombosis                                                    1 (2%)                                                          
      Artery, Inflammation                                                       1 (2%)                                             
      Atrium, Thrombosis                               2 (4%)                                                                       
      Ventricle, Thrombosis                                                      1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (48)                                   
      Degeneration, Cystic                                                                    1 (2%)                                
      Hyperplasia                                      4 (8%)      10 (20%)      7 (14%)      4 (8%)                                
      Hypertrophy                                     38 (76%)     33 (66%)     38 (76%)     30 (63%)                               
      Mineralization                                                             1 (2%)                                             
   Adrenal Medulla                                    (50)         (50)         (50)         (47)                                   
      Hyperplasia                                                                             1 (2%)                                
   Islets, Pancreatic                                 (50)         (48)         (49)         (47)                                   
      Hyperplasia                                      2 (4%)       3 (6%)       2 (4%)       4 (9%)                                
   Pituitary Gland                                    (48)         (48)         (47)         (47)                                   
      Pars Distalis, Hyperplasia                                    1 (2%)       1 (2%)       1 (2%)                                
   Thyroid Gland                                      (50)         (50)         (50)         (48)                                   
      Follicular Cell, Hyperplasia                    11 (22%)     13 (26%)      7 (14%)      8 (17%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (49)                                   
      Granuloma Sperm                                               2 (4%)                    1 (2%)                                
      Hyperplasia                                      1 (2%)       1 (2%)                                                          
      Inflammation                                     2 (4%)       1 (2%)                                                          
   Preputial Gland                                    (50)         (49)         (49)         (48)                                   
      Ectasia                                          5 (10%)      3 (6%)       5 (10%)      5 (10%)                               
      Inflammation                                     3 (6%)       3 (6%)       4 (8%)       9 (19%)                               
   Prostate                                           (50)         (49)         (49)         (49)                                   
      Inflammation                                     2 (4%)                    1 (2%)       1 (2%)                                
   Seminal Vesicle                                    (50)         (50)         (48)         (43)                                   
      Inflammation                                                  1 (2%)                    1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Atrophy                                          6 (12%)      9 (18%)      2 (4%)       2 (4%)                                
____________________________________________________________________________________________________________________________________

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (49)         (50)         (50)         (48)                                   
      Hyperplasia                                      2 (4%)       3 (6%)       2 (4%)       3 (6%)                                
   Lymph Node                                         (2)                       (2)          (1)                                    
      Hyperplasia                                      1 (50%)                                                                      
   Lymph Node, Bronchial                              (38)         (37)         (40)         (41)                                   
      Hyperplasia                                      5 (13%)      7 (19%)     17 (43%)     24 (59%)                               
   Lymph Node, Mandibular                             (37)         (40)         (28)         (32)                                   
      Hyperplasia                                      2 (5%)       3 (8%)                                                          
   Lymph Node, Mesenteric                             (48)         (49)         (50)         (46)                                   
      Angiectasis                                                   1 (2%)       1 (2%)       1 (2%)                                
      Erythrophagocytosis                                           1 (2%)                                                          
      Hematopoietic Cell Proliferation                 1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Hyperplasia                                      3 (6%)       5 (10%)      4 (8%)       4 (9%)                                
   Lymph Node, Mediastinal                            (38)         (36)         (38)         (33)                                   
      Hematopoietic Cell Proliferation                              1 (3%)                                                          
      Hyperplasia                                      1 (3%)       1 (3%)       4 (11%)      3 (9%)                                
   Spleen                                             (50)         (50)         (49)         (47)                                   
      Hematopoietic Cell Proliferation                17 (34%)     13 (26%)     19 (39%)     18 (38%)                               
      Hyperplasia, Lymphoid                            1 (2%)       5 (10%)      3 (6%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                                  1 (2%)                                             
      Inflammation                                     1 (2%)                                 1 (2%)                                
      Prepuce, Inflammation, Chronic Active            2 (4%)       4 (8%)       3 (6%)       3 (6%)                                
      Subcutaneous Tissue, Inflammation, Chronic                                 2 (4%)                                             
      Subcutaneous Tissue, Inflammation, Focal,                                                                                     
           Suppurative                                              1 (2%)                                                          
      Subcutaneous Tissue, Inflammation,                                                                                            
          Granulomatous                                1 (2%)       1 (2%)                    1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (49)         (50)         (50)         (50)                                   
      Fibrous Osteodystrophy                           1 (2%)       2 (4%)       2 (4%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (49)                                   
      Meninges, Infiltration Cellular, Mononuclear                                                                                  
          Cell                                                                   1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (50)         (48)         (48)                                   
      Inflammation, Suppurative                                     1 (2%)       1 (2%)                                             
      Metaplasia, Squamous                             1 (2%)                                                                       
      Squamous Epithelium, Hyperplasia                11 (22%)     13 (26%)     11 (23%)      5 (10%)                               
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                                           1 (2%)       1 (2%)                                
      Hemorrhage                                       5 (10%)      6 (12%)      6 (12%)      3 (6%)                                
      Hyperplasia, Atypical                                                                   1 (2%)                                
      Infiltration Cellular, Histiocyte                3 (6%)      10 (20%)     45 (90%)     48 (96%)                               
      Inflammation, Chronic, Focal                     1 (2%)       3 (6%)       3 (6%)      12 (24%)                               
      Inflammation, Focal, Suppurative                                           8 (16%)     23 (46%)                               
      Alveolar Epithelium, Hyperplasia                 4 (8%)       9 (18%)     39 (78%)     45 (90%)                               
      Alveolus, Foreign Body                                        4 (8%)      46 (92%)     50 (100%)                              
      Alveolus, Proteinosis                            1 (2%)       4 (8%)      49 (98%)     50 (100%)                              
   Nose                                               (49)         (49)         (49)         (48)                                   
      Inflammation, Suppurative                                     3 (6%)       2 (4%)       1 (2%)                                
      Olfactory Epithelium, Atrophy                    7 (14%)      2 (4%)       5 (10%)      8 (17%)                               
      Olfactory Epithelium, Degeneration, Hyaline      2 (4%)       4 (8%)       6 (12%)      1 (2%)                                
      Respiratory Epithelium, Degeneration, Hyaline    1 (2%)       2 (4%)       2 (4%)       1 (2%)                                
      Respiratory Epithelium, Hyperplasia                           1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (2)          (1)                       (4)                                    
      Degeneration                                                  1 (100%)                  2 (50%)                               
      Cornea, Inflammation, Chronic                    1 (50%)                                                                      
   Harderian Gland                                    (47)         (48)         (49)         (48)                                   
      Hyperplasia                                      1 (2%)       1 (2%)      10 (20%)      1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (49)         (48)                                   
      Cyst                                             1 (2%)                                                                       
      Hydronephrosis                                   2 (4%)       3 (6%)       2 (4%)       3 (6%)                                
      Infarct                                                       1 (2%)                                                          
      Inflammation, Chronic Active                     1 (2%)                    1 (2%)       1 (2%)                                

a  Number of animals examined microscopically at site and number of animals with lesion                                             
NTP Experiment-Test: 05180-07         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                          GALLIUM ARSENIDE                                     Date: 03/09/99  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 14:17:25  
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          CONTROL      0.1          0.5          1.0                                       
                                                                MG/M3        MG/M3        MG/M3                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Metaplasia, Osseous                                           1 (2%)       4 (8%)                                             
      Nephropathy                                     48 (96%)     49 (98%)     45 (92%)     47 (98%)                               
      Capsule, Inflammation                                         1 (2%)       2 (4%)                                             
      Cortex, Cyst                                     2 (4%)       4 (8%)                    2 (4%)                                
      Renal Tubule, Hyperplasia                        2 (4%)                    3 (6%)       1 (2%)                                
      Renal Tubule, Necrosis                                                     1 (2%)                                             
   Urinary Bladder                                    (49)         (50)         (46)         (46)                                   
      Inflammation                                     1 (2%)                                 2 (4%)                                
      Transitional Epithelium, Hyperplasia             1 (2%)                                                                       
                                                                                                                                    

a  Number of animals examined microscopically at site and number of animals with lesion                                             
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
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