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TDMS Study 89006-08 Pathology Tables

NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47




       Facility:  Southern Research Institute

       Chemical CAS #:  76543-88-9

       Lock Date:  09/03/93

       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: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                13           13            9           11                                     
    Natural Death                                     12            5           15            8                                     
    Dosing Accident                                                              1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                25           32           25           31                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Rectum                            (47)         (50)         (50)         (49)                                   
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
   Intestine Small, Jejunum                           (47)         (50)         (49)         (48)                                   
      Peyer's Patch, Hyperplasia, Lymphoid             1 (2%)                                                                       
   Liver                                              (49)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)       2 (4%)                    3 (6%)                                
      Basophilic Focus                                                           3 (6%)       1 (2%)                                
      Clear Cell Focus                                 1 (2%)       1 (2%)       1 (2%)                                             
      Congestion                                       1 (2%)                                                                       
      Eosinophilic Focus                               1 (2%)       8 (16%)      8 (16%)      8 (16%)                               
      Fibrosis, Focal                                                            1 (2%)                                             
      Hematopoietic Cell Proliferation                 1 (2%)       3 (6%)                    1 (2%)                                
      Hyperplasia, Focal, Lymphoid                                               1 (2%)                                             
      Inflammation, Chronic                            4 (8%)       6 (12%)     10 (20%)      9 (18%)                               
      Mixed Cell Focus                                 4 (8%)       4 (8%)                    1 (2%)                                
      Necrosis, Focal                                  3 (6%)       5 (10%)      5 (10%)      3 (6%)                                
      Pigmentation, Focal                              2 (4%)       2 (4%)       1 (2%)       1 (2%)                                
      Vacuolization Cytoplasmic                        5 (10%)      2 (4%)       3 (6%)       3 (6%)                                
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
      Bile Duct, Cyst                                               1 (2%)                    1 (2%)                                
      Bile Duct, Hyperplasia                           1 (2%)                                 1 (2%)                                
      Hepatocyte, Karyomegaly                          2 (4%)       1 (2%)       1 (2%)                                             
   Mesentery                                          (21)         (21)         (18)         (16)                                   
      Accessory Spleen                                              1 (5%)                                                          
      Angiectasis                                                   1 (5%)                                                          
      Fibrosis, Focal                                                            1 (6%)                                             
      Infiltration Cellular, Mixed Cell                                          1 (6%)                                             
      Inflammation, Chronic                                         1 (5%)       3 (17%)                                            
      Artery, Inflammation, Chronic                    1 (5%)                                 2 (13%)                               
      Fat, Necrosis                                   13 (62%)     12 (57%)     12 (67%)     10 (63%)                               
   Pancreas                                           (48)         (50)         (50)         (50)                                   
      Inflammation, Chronic                                                      1 (2%)                                             
      Necrosis, Focal                                                            1 (2%)                                             

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

                                                             Page    2                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Acinus, Atrophy, Diffuse                                                   2 (4%)                                             
      Acinus, Atrophy, Focal                                        1 (2%)       1 (2%)                                             
      Duct, Cyst                                                                 3 (6%)                                             
   Salivary Glands                                    (50)         (50)         (48)         (49)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
   Stomach, Forestomach                               (48)         (50)         (50)         (46)                                   
      Diverticulum                                     2 (4%)                                                                       
      Edema                                                                                   1 (2%)                                
      Erosion                                          5 (10%)                   3 (6%)       1 (2%)                                
      Inflammation, Chronic                            3 (6%)                    3 (6%)       3 (7%)                                
      Epithelium, Cyst                                                                        1 (2%)                                
      Epithelium, Hyperplasia                          7 (15%)                   4 (8%)       4 (9%)                                
   Stomach, Glandular                                 (48)         (50)         (50)         (46)                                   
      Erosion                                          1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Mineralization                                   1 (2%)                                                                       
      Pigmentation, Focal                              1 (2%)       2 (4%)       2 (4%)                                             
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
      Glands, Degeneration, Cystic, Focal              1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (50)         (50)         (49)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
      Pulmonary Vein, Intima, Mineralization, Focal                 1 (2%)                                                          
   Heart                                              (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic, Focal                                  1 (2%)                    1 (2%)                                
      Thrombosis                                                                 1 (2%)                                             
      Artery, Inflammation, Chronic                    1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (49)                                   
      Accessory Adrenal Cortical Nodule                3 (6%)                    1 (2%)                                             
      Cyst                                             1 (2%)                                                                       
      Cytoplasmic Alteration, Focal                                                           1 (2%)                                
      Hyperplasia                                                                             1 (2%)                                
      Hypertrophy, Focal                                                                      1 (2%)                                
      Capsule, Hyperplasia, Focal                      1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
   Adrenal Medulla                                    (50)         (49)         (50)         (49)                                   
      Hyperplasia                                                                             2 (4%)                                
   Islets, Pancreatic                                 (48)         (50)         (50)         (50)                                   
      Hyperplasia                                                   1 (2%)                                                          
   Parathyroid Gland                                  (44)         (46)         (46)         (47)                                   
      Cyst                                                          1 (2%)                    1 (2%)                                
   Pituitary Gland                                    (46)         (47)         (44)         (43)                                   

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

                                                             Page    3                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Angiectasis                                      1 (2%)       3 (6%)       1 (2%)       3 (7%)                                
      Pars Distalis, Cytoplasmic Alteration, Focal     1 (2%)       3 (6%)       4 (9%)       2 (5%)                                
      Pars Distalis, Hyperplasia, Focal                1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
   Thyroid Gland                                      (50)         (50)         (49)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Degeneration, Cystic, Focal                      8 (16%)      9 (18%)     10 (20%)      8 (16%)                               
      Inflammation, Chronic, Focal                                  2 (4%)       1 (2%)       1 (2%)                                
      C-Cell, Hyperplasia                                                        1 (2%)       1 (2%)                                
      Follicle, Cyst                                   2 (4%)       1 (2%)       1 (2%)                                             
      Follicular Cell, Hyperplasia                    17 (34%)     21 (42%)     18 (37%)     14 (28%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Peritoneum                                         (2)                       (1)                                                 
      Infiltration Cellular, Histiocyte                1 (50%)                                                                      
      Infiltration Cellular, Mixed Cell                                          1 (100%)                                           
   Tissue NOS                                         (1)          (1)          (2)                                                 
      Hemorrhage                                                                 1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (48)         (49)         (47)         (49)                                   
      Degeneration, Cystic                             3 (6%)       3 (6%)       2 (4%)       6 (12%)                               
   Ovary                                              (46)         (48)         (49)         (48)                                   
      Angiectasis                                                   2 (4%)                    3 (6%)                                
      Atrophy                                                                                 1 (2%)                                
      Cyst                                            10 (22%)     11 (23%)      7 (14%)      8 (17%)                               
      Inflammation, Suppurative                                                  1 (2%)                                             
      Thrombosis                                                                 1 (2%)                                             
      Bilateral, Cyst                                               1 (2%)       2 (4%)       1 (2%)                                
   Oviduct                                                                      (1)                                                 
      Inflammation, Suppurative                                                  1 (100%)                                           
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Angiectasis                                                                1 (2%)                                             
      Hydrometra                                      10 (20%)     11 (22%)     11 (22%)     20 (40%)                               
      Inflammation, Suppurative                        1 (2%)       2 (4%)       1 (2%)       1 (2%)                                
      Thrombosis                                                                              1 (2%)                                
      Endometrium, Hyperplasia, Cystic                48 (96%)     49 (98%)     46 (92%)     48 (96%)                               
   Vagina                                             (48)         (50)         (47)         (46)                                   
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Focal, Granulomatous               1 (2%)                                                                       
      Epithelium, Hyperplasia                                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    4                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Depletion Cellular                                            1 (2%)                                                          
      Hyperplasia                                      2 (4%)       2 (4%)                                                          
   Lymph Node                                         (12)         (13)         (9)          (11)                                   
      Iliac, Hemorrhage                                1 (8%)                                                                       
      Iliac, Hyperplasia                                                                      1 (9%)                                
      Iliac, Hyperplasia, Lymphoid                                  1 (8%)                                                          
      Inguinal, Hyperplasia                            2 (17%)                                                                      
      Inguinal, Hyperplasia, Lymphoid                                            1 (11%)      1 (9%)                                
      Mediastinal, Hyperplasia                                      1 (8%)       2 (22%)      1 (9%)                                
      Mediastinal, Hyperplasia, Lymphoid               1 (8%)       2 (15%)      1 (11%)                                            
      Mediastinal, Inflammation, Focal, Suppurative                              1 (11%)      1 (9%)                                
      Pancreatic, Hyperplasia, Lymphoid                             1 (8%)                                                          
      Renal, Hemorrhage                                1 (8%)                                                                       
      Renal, Hyperplasia, Lymphoid                                  1 (8%)                    1 (9%)                                
   Lymph Node, Mandibular                             (49)         (49)         (47)         (48)                                   
      Hemorrhage                                                    1 (2%)                                                          
      Hyperplasia                                                   1 (2%)       1 (2%)                                             
      Hyperplasia, Lymphoid                            1 (2%)       2 (4%)       1 (2%)       2 (4%)                                
   Lymph Node, Mesenteric                             (45)         (50)         (50)         (47)                                   
      Angiectasis                                      1 (2%)                    1 (2%)                                             
      Ectasia                                                       2 (4%)                    1 (2%)                                
      Hematopoietic Cell Proliferation                              1 (2%)                                                          
      Hemorrhage                                       2 (4%)       2 (4%)       1 (2%)                                             
      Hyperplasia                                                                2 (4%)                                             
      Hyperplasia, Histiocytic                                                   1 (2%)                                             
      Hyperplasia, Lymphoid                            3 (7%)       4 (8%)       3 (6%)       2 (4%)                                
      Inflammation, Focal, Suppurative                                           1 (2%)                                             
      Pigmentation                                                  1 (2%)                                                          
   Spleen                                             (47)         (50)         (50)         (49)                                   
      Hematopoietic Cell Proliferation                21 (45%)     24 (48%)     26 (52%)     20 (41%)                               
      Hyperplasia, Histiocytic                                                   1 (2%)                                             
      Hyperplasia, Lymphoid                            3 (6%)       4 (8%)       2 (4%)       5 (10%)                               
      Necrosis, Focal                                  1 (2%)                                                                       
   Thymus                                             (41)         (48)         (48)         (39)                                   
      Cyst                                             1 (2%)       2 (4%)       2 (4%)                                             
      Hyperplasia, Histiocytic                                                                1 (3%)                                
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)                                             
      Epithelial Cell, Hyperplasia                                  1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    5                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (48)         (50)         (50)                                   
      Ectasia                                          1 (2%)       1 (2%)                    2 (4%)                                
      Hyperplasia                                                   1 (2%)       1 (2%)       1 (2%)                                
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                                  1 (2%)                                             
      Inflammation, Chronic, Focal                     1 (2%)                                                                       
      Ulcer                                            1 (2%)                                                                       
      Artery, Subcutaneous Tissue, Inflammation,                                                                                    
           Chronic                                     1 (2%)                                                                       
      Subcutaneous Tissue, Edema                       1 (2%)       2 (4%)                                                          
      Subcutaneous Tissue, Hemorrhage, Focal                                                  1 (2%)                                
      Subcutaneous Tissue, Inflammation, Chronic,                                                                                   
           Focal                                                                 1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fibrous Osteodystrophy                                                     1 (2%)                                             
      Osteoporosis                                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (49)         (50)         (50)                                   
      Atrophy, Focal                                   2 (4%)       2 (4%)       1 (2%)       1 (2%)                                
      Hemorrhage, Focal                                1 (2%)                                                                       
   Spinal Cord                                        (2)          (2)          (4)          (1)                                    
      Hemorrhage, Focal                                                          1 (25%)                                            
      Meninges, Inflammation, Focal                                              1 (25%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Hemorrhage                                       2 (4%)       2 (4%)       2 (4%)       1 (2%)                                
      Hyperplasia, Histiocytic                         4 (8%)       2 (4%)       1 (2%)       3 (6%)                                
      Hyperplasia, Lymphoid                            1 (2%)                    1 (2%)                                             
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Pigmentation, Focal                              1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
      Bronchus, Glands, Cyst                                                     1 (2%)                                             
      Mediastinum, Infiltration Cellular, Mixed                                                                                     
          Cell                                                                   1 (2%)                                             
      Mediastinum, Inflammation, Chronic                                         1 (2%)       1 (2%)                                
      Mediastinum, Necrosis, Focal                                               1 (2%)                                             

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

                                                             Page    6                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE FEMALE                        VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
   Nose                                               (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                                                               1 (2%)                                
      Mucosa, Glands, Dilatation, Focal               41 (82%)     42 (84%)     41 (82%)     40 (80%)                               
      Nasolacrimal Duct, Cyst                                                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                             (3)                       (1)                                    
      Atrophy                                                       1 (33%)                                                         
      Inflammation, Chronic                                         1 (33%)                                                         
      Anterior Chamber, Infiltration Cellular,                                                                                      
           Polymorphonuclear                                        1 (33%)                                                         
      Cornea, Inflammation, Chronic                                 2 (67%)                   1 (100%)                              
      Cornea, Necrosis, Focal                                       1 (33%)                                                         
   Harderian Gland                                    (3)          (8)          (4)          (3)                                    
      Hyperplasia, Focal                                            1 (13%)      1 (25%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (48)         (50)         (49)         (50)                                   
      Cyst                                             1 (2%)                                 1 (2%)                                
      Metaplasia, Focal, Osseous                       3 (6%)       1 (2%)       2 (4%)                                             
      Nephropathy                                     29 (60%)     38 (76%)     31 (63%)     31 (62%)                               
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
      Pelvis, Dilatation                               2 (4%)                                 1 (2%)                                
      Renal Tubule, Accumulation, Hyaline Droplet                   3 (6%)       1 (2%)       2 (4%)                                
      Renal Tubule, Dilatation                         2 (4%)       3 (6%)                                                          
      Renal Tubule, Hyperplasia, Focal                                           1 (2%)                                             
      Renal Tubule, Necrosis                           1 (2%)                    1 (2%)                                             
      Renal Tubule, Pigmentation                                                 2 (4%)       2 (4%)                                
   Urethra                                            (1)                       (1)                                                 
      Inflammation, Chronic                                                      1 (100%)                                           
      Artery, Inflammation, Chronic                    1 (100%)                                                                     
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
                                                                                                                                    

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

                                                             Page    7                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Natural Death                                     10           15           11           13                                     
    Moribund Sacrifice                                13            7           10           10                                     
    Dosing Accident                                                              1                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                27           28           28           27                                     

  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (45)         (45)         (48)         (43)                                   
      Inflammation, Chronic                                                      1 (2%)                                             
   Intestine Large, Cecum                             (49)         (49)         (49)         (50)                                   
      Congestion                                       1 (2%)       1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Basophilic Focus                                              1 (2%)       2 (4%)       1 (2%)                                
      Clear Cell Focus                                 1 (2%)       1 (2%)       6 (12%)      2 (4%)                                
      Congestion                                                                 1 (2%)                                             
      Eosinophilic Focus                               9 (18%)      3 (6%)       4 (8%)       5 (10%)                               
      Hematopoietic Cell Proliferation                 1 (2%)                                                                       
      Infarct                                          1 (2%)                                                                       
      Inflammation, Chronic                           15 (30%)     17 (34%)     18 (36%)     20 (40%)                               
      Mixed Cell Focus                                 1 (2%)                    4 (8%)       2 (4%)                                
      Necrosis, Focal                                  4 (8%)       1 (2%)       5 (10%)      7 (14%)                               
      Pigmentation, Focal                              2 (4%)                    1 (2%)       3 (6%)                                
      Vacuolization Cytoplasmic                        1 (2%)       2 (4%)                    1 (2%)                                
      Bile Duct, Cyst                                               1 (2%)                                                          
      Bile Duct, Hyperplasia                           8 (16%)      9 (18%)      8 (16%)      7 (14%)                               
      Centrilobular, Necrosis                                                                 1 (2%)                                
      Hepatocyte, Karyomegaly                         12 (24%)     14 (28%)      8 (16%)     12 (24%)                               
   Mesentery                                          (7)          (5)          (6)          (9)                                    
      Angiectasis                                      1 (14%)      1 (20%)                                                         
      Inflammation, Chronic                            1 (14%)      1 (20%)      2 (33%)      3 (33%)                               
      Artery, Inflammation, Chronic                    2 (29%)                   1 (17%)      4 (44%)                               
      Fat, Necrosis                                    1 (14%)                                                                      
   Pancreas                                           (49)         (49)         (49)         (49)                                   
      Inflammation, Chronic                                         1 (2%)       1 (2%)                                             
      Acinus, Atrophy, Diffuse                                                   2 (4%)                                             
      Duct, Cyst                                                                              1 (2%)                                
   Stomach, Forestomach                               (50)         (48)         (49)         (50)                                   
      Diverticulum                                     1 (2%)       1 (2%)       1 (2%)                                             
      Erosion                                          2 (4%)                    2 (4%)       2 (4%)                                

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

                                                             Page    8                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Chronic                            3 (6%)       2 (4%)       4 (8%)       1 (2%)                                
      Epithelium, Cyst                                                           1 (2%)                                             
      Epithelium, Hyperplasia                          5 (10%)      3 (6%)       5 (10%)      2 (4%)                                
      Muscularis, Serosa, Inflammation, Suppurative                              1 (2%)                                             
   Stomach, Glandular                                 (50)         (48)         (49)         (50)                                   
      Erosion                                                                    2 (4%)       1 (2%)                                
      Inflammation, Chronic                                                      2 (4%)                                             
      Metaplasia, Hepatocyte                           1 (2%)                    1 (2%)                                             
      Mineralization                                                             1 (2%)                                             
      Pigmentation, Focal                                           1 (2%)       2 (4%)       3 (6%)                                
      Epithelium, Hyperplasia                                                    2 (4%)                                             
      Glands, Degeneration, Cystic, Focal              2 (4%)       2 (4%)       1 (2%)                                             
      Muscularis, Serosa, Inflammation, Suppurative                              1 (2%)                                             
   Tooth                                              (24)         (14)         (24)         (20)                                   
      Developmental Malformation                      24 (100%)    14 (100%)    24 (100%)    20 (100%)                              
      Inflammation, Chronic, Suppurative               1 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (50)         (50)         (48)         (50)                                   
      Mineralization                                   1 (2%)                                                                       
   Heart                                              (50)         (50)         (50)         (50)                                   
      Mineralization                                   1 (2%)                                                                       
      Thrombosis                                       1 (2%)       1 (2%)                    1 (2%)                                
      Artery, Inflammation, Chronic                    1 (2%)                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (49)                                   
      Accessory Adrenal Cortical Nodule                1 (2%)       1 (2%)       1 (2%)                                             
      Angiectasis                                      1 (2%)                                                                       
      Cyst                                             1 (2%)                    1 (2%)                                             
      Cytoplasmic Alteration, Focal                    3 (6%)       2 (4%)       5 (10%)      1 (2%)                                
      Hyperplasia, Focal                               1 (2%)                    1 (2%)                                             
      Inflammation, Chronic, Focal                     1 (2%)                                                                       
      Capsule, Hyperplasia, Focal                      3 (6%)      10 (20%)      3 (6%)       6 (12%)                               
   Adrenal Medulla                                    (49)         (49)         (50)         (49)                                   
      Hyperplasia                                      6 (12%)      1 (2%)       1 (2%)       3 (6%)                                
   Islets, Pancreatic                                 (50)         (48)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)                                                                       
   Parathyroid Gland                                  (49)         (41)         (45)         (43)                                   
      Cyst                                             1 (2%)                    2 (4%)       1 (2%)                                
   Pituitary Gland                                    (45)         (47)         (47)         (41)                                   
      Pars Distalis, Cyst                              2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
      Pars Distalis, Cytoplasmic Alteration, Focal                  1 (2%)       1 (2%)       1 (2%)                                

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

                                                             Page    9                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Distalis, Hyperplasia, Focal                             1 (2%)                                                          
   Thyroid Gland                                      (50)         (49)         (50)         (50)                                   
      Degeneration, Cystic, Focal                      3 (6%)       3 (6%)       7 (14%)      4 (8%)                                
      Inflammation, Chronic, Focal                                               1 (2%)                                             
      C-Cell, Hyperplasia                              1 (2%)                                                                       
      Follicle, Cyst                                                1 (2%)       1 (2%)                                             
      Follicular Cell, Hyperplasia                     7 (14%)      6 (12%)     11 (22%)      8 (16%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                                            (2)                                                 
      Inflammation, Chronic                                                      1 (50%)                                            
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Granuloma Sperm                                               1 (2%)                    1 (2%)                                
      Inflammation, Chronic                                                      1 (2%)                                             
      Mineralization, Focal                            1 (2%)                                                                       
      Spermatocele                                                  1 (2%)       1 (2%)                                             
   Preputial Gland                                    (50)         (50)         (50)         (50)                                   
      Degeneration, Cystic                            17 (34%)     16 (32%)     14 (28%)     11 (22%)                               
      Inflammation, Chronic                            2 (4%)       3 (6%)       6 (12%)      5 (10%)                               
   Prostate                                           (49)         (49)         (50)         (49)                                   
      Inflammation, Chronic, Focal                     2 (4%)       2 (4%)       4 (8%)                                             
      Epithelium, Hyperplasia, Focal                                1 (2%)                                                          
   Seminal Vesicle                                    (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic                                         1 (2%)       1 (2%)                                             
   Testes                                             (50)         (50)         (50)         (50)                                   
      Cyst                                                                       1 (2%)                                             
      Mineralization, Focal                                                      2 (4%)                                             
      Germinal Epithelium, Degeneration                                                       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Hyperplasia                                                                2 (4%)       1 (2%)                                
      Hyperplasia, Focal, Histiocytic                               1 (2%)                                                          
   Lymph Node                                         (3)          (3)          (6)          (3)                                    
      Iliac, Hyperplasia                                                                      1 (33%)                               
      Inguinal, Hyperplasia                                                      1 (17%)      1 (33%)                               
      Inguinal, Hyperplasia, Lymphoid                                            1 (17%)                                            

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

                                                             Page   10                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Inguinal, Pigmentation                                                                  1 (33%)                               
   Lymph Node, Mandibular                             (47)         (46)         (45)         (45)                                   
      Hyperplasia                                      1 (2%)                    1 (2%)                                             
   Lymph Node, Mesenteric                             (50)         (48)         (46)         (50)                                   
      Angiectasis                                      3 (6%)       2 (4%)       1 (2%)       1 (2%)                                
      Hematopoietic Cell Proliferation                 2 (4%)       3 (6%)       3 (7%)       5 (10%)                               
      Hemorrhage                                      13 (26%)      9 (19%)     15 (33%)     12 (24%)                               
      Hyperplasia, Histiocytic                                      1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)       2 (4%)       4 (9%)       4 (8%)                                
   Spleen                                             (49)         (49)         (49)         (50)                                   
      Angiectasis                                                   1 (2%)                                                          
      Hematopoietic Cell Proliferation                21 (43%)     19 (39%)     16 (33%)     15 (30%)                               
      Hemorrhage                                                                              1 (2%)                                
      Hyperplasia, Lymphoid                                         1 (2%)                    1 (2%)                                
   Thymus                                             (38)         (38)         (35)         (39)                                   
      Cyst                                             2 (5%)       5 (13%)      4 (11%)      2 (5%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (49)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                                               1 (2%)                                
      Inflammation, Chronic, Focal                                               1 (2%)                                             
      Artery, Subcutaneous Tissue, Inflammation,                                                                                    
           Chronic                                     1 (2%)                                                                       
      Hair Follicle, Atrophy                                                     2 (4%)                                             
      Subcutaneous Tissue, Angiectasis, Focal                                                 1 (2%)                                
      Subcutaneous Tissue, Edema                       2 (4%)       3 (6%)                    1 (2%)                                
      Subcutaneous Tissue, Inflammation, Chronic,                                                                                   
           Focal                                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Fracture                                         1 (2%)                                                                       
      Hyperostosis                                     1 (2%)                                                                       
   Skeletal Muscle                                    (50)         (50)         (50)         (50)                                   
      Hemorrhage, Focal                                                          1 (2%)                                             
      Inflammation, Suppurative                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page   11                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Spinal Cord                                        (1)          (2)          (4)          (2)                                    
      Hemorrhage, Focal                                                          1 (25%)      1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Hemorrhage                                       1 (2%)       2 (4%)                    2 (4%)                                
      Hyperplasia, Histiocytic                         4 (8%)       2 (4%)       1 (2%)       2 (4%)                                
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Infiltration Cellular, Mixed Cell                             1 (2%)                                                          
      Inflammation, Chronic                            1 (2%)                                                                       
      Thrombosis                                       1 (2%)                                                                       
      Alveolar Epithelium, Hyperplasia                 1 (2%)       1 (2%)                    2 (4%)                                
      Bronchus, Glands, Cyst                                                     3 (6%)       1 (2%)                                
      Mediastinum, Hemorrhage                                                                 1 (2%)                                
   Nose                                               (50)         (50)         (50)         (50)                                   
      Inflammation, Suppurative                        1 (2%)       1 (2%)       2 (4%)       1 (2%)                                
      Mucosa, Polyp, Inflammatory                      2 (4%)                                 2 (4%)                                
      Mucosa, Glands, Dilatation, Focal               25 (50%)     24 (48%)     26 (52%)     26 (52%)                               
      Nasolacrimal Duct, Cyst                          1 (2%)                                                                       
      Nasolacrimal Duct, Dilatation                                              1 (2%)                                             
      Nasopharyngeal Duct, Hyperplasia, Focal                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (4)          (6)          (8)          (4)                                    
      Degeneration, Cystic, Focal                                                1 (13%)                                            
      Hyperplasia, Focal                                                         1 (13%)                                            
      Inflammation, Chronic, Focal                     1 (25%)                   1 (13%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (49)         (49)         (49)         (50)                                   
      Congestion                                       1 (2%)                                 1 (2%)                                
      Cyst                                             1 (2%)                                                                       
      Infarct                                                       2 (4%)       2 (4%)                                             
      Metaplasia, Focal, Osseous                       2 (4%)       4 (8%)                                                          
      Nephropathy                                     46 (94%)     44 (90%)     46 (94%)     49 (98%)                               
      Artery, Inflammation, Chronic                    1 (2%)                                                                       
      Pelvis, Dilatation                                            2 (4%)       3 (6%)       1 (2%)                                
      Renal Tubule, Dilatation                         1 (2%)       2 (4%)                    3 (6%)                                
      Renal Tubule, Pigmentation                       1 (2%)                                 2 (4%)                                
   Urethra                                            (9)          (14)         (16)         (15)                                   

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

                                                             Page   12                                                              
NTP Experiment-Test: 89006-08         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                     INTERFERON A/INTERFERON AD                                Date: 12/23/96    
Route: SUBCUTANEOUS                                                                                               Time: 17:05:47    
____________________________________________________________________________________________________________________________________

         B6C3F1 MICE MALE                          VEHICLE      500 U        5000 U       5000 U A                                  
                                                   CONTROL      A/D          A/D                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Inflammation, Chronic                            2 (22%)      6 (43%)      4 (25%)      2 (13%)                               
                                                                                                                                    

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

                                                             Page   13                                                              
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