ABSTRACT
In a preliminary study, hydrocortisone-treated rats developed pseudotuberculosis when challenged with 6.2 X 10(5) to 3.1 X 10(7) colony forming units of Corynebacterium kutscheri by intranasal, intragastric, or subcutaneous inoculation. Oronasal exposure was selected as a likely natural route to further study inapparent infection. In Study 1, 50 rats received 1.2 X 10(5) colony forming units and various tissues were cultured at intervals to 12 weeks post-inoculation. At each interval, C. kutscheri was regularly isolated from submaxillary lymph nodes, but isolation was sporadic from other sites. In Study 2, 17 out of 21 rats given 1.2 X 10(5) colony forming units and killed weekly for 6 weeks had 2.0 X 10(2) to 1.8 X 10(5) colony forming units of C. kutscheri in oral washes, and 16 rats had 2.0 X 10(2) to 1.0 X 10(5) colony forming units in submaxillary lymph nodes, Serum antibody to C. kutscheri using both microagglutination and indirect immunofluorescence was first detected in some rats by 2 weeks, and in all rats at subsequent intervals. There was a significant (P less than 0.001) positive correlation (r = 0.93) between serum antibody titers and the duration of infection.
Subject(s)
Rodent Diseases/microbiology , Sarcoidosis/veterinary , Animals , Antibodies/analysis , Cecum/microbiology , Female , Lymph Nodes/microbiology , Rats , Rodent Diseases/immunology , Sarcoidosis/immunology , Sarcoidosis/microbiologyABSTRACT
4,4'-Methylene bis (2-carbomethoxyaniline), also known as methylene-bis methyl anthranilate (MBMA), was added to the diet of male and female ChR-CD rats for up to two years at levels of 0, 1500, and 15,000 ppm. Fifty rats of each sex were used at each dietary level. Female rats at both dietary levels of MBMA had a lower body weight gain and lower food efficiency values than did the controls. High-level males and females showed a slight anemia; all other clinical laboratory tests were within normal limits. MBMA caused slight degenerative histologic changes in the liver and kidney of both sexes at both dietary levels. High-level males developed a statistically significant increase in kidney and liver tumors when compared to controls (p less than 0.05, Fisher's Exact Test, one tail). High-level females had an elevated kidney tumor incidence compared with controls (p less than 0.10). There was a statistically significant lower incidence in pituitary tumors in high-level males (p less than 0.05) and in high-level females (p less than 0.10) than in controls. High-level females had a lower incidence of mammary tumors (p less than 0.05) compared to controls. MBMA was considered to be a carcinogen of moderate potency in rats, since tumors were not found until 18 months on test using a comparative large dose (1.5% of diet).
Subject(s)
Benzhydryl Compounds/toxicity , Kidney Neoplasms/chemically induced , Liver Neoplasms/chemically induced , ortho-Aminobenzoates/toxicity , Animals , Body Weight/drug effects , Diet , Eating/drug effects , Female , Kidney Neoplasms/pathology , Liver Neoplasms/pathology , Male , Rats , Time FactorsABSTRACT
Extensive toxicological studies were carried out to define the probable hazard of octabromobiphenyl (OBB) to workers, users, and the environment. OBB had low acute toxicity in mammals and birds by various routes of administration. It was essentially non-irritating to rabbit eyes, non-irritating to human skin and caused only mild skin irritation and no sensitization in the guinea pig. OBB caused equivocal effects in the rat fetus. OBB was stored in the body fat of rats and caused liver enlargement at high single doses or low repeated doses. The studies indicate probable low safety factors in application and use and probable bioaccumulation. Hexabromobiphenyl (HBB) was more acutely toxic than OBB by skin absorption in the rabbit and caused liver enlargement at lower single doses.
Subject(s)
Biphenyl Compounds/toxicity , Polybrominated Biphenyls/toxicity , Abnormalities, Drug-Induced/etiology , Animals , Body Weight , Dermatitis, Contact/etiology , Diet , Environmental Exposure , Eye/drug effects , Female , Fetus/drug effects , Guinea Pigs , Hepatomegaly/chemically induced , Humans , Liver/drug effects , Male , Organ Size , Polybrominated Biphenyls/administration & dosage , Quail , Rabbits , Rats , Skin/drug effects , Skin AbsorptionSubject(s)
Biphenyl Compounds/toxicity , Bromine/metabolism , Chemical and Drug Induced Liver Injury/etiology , Adipose Tissue/metabolism , Animals , Biphenyl Compounds/metabolism , Body Weight/drug effects , Bromine/toxicity , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/pathology , Liver/metabolism , Liver/pathology , Liver/ultrastructure , Male , Muscles/metabolism , Organ Size/drug effects , Rats , Time FactorsABSTRACT
Single oral administration of octabromobiphenyls at 1,000 mg/kg, or two consecutive doses of 3,000 mg/kg, to rats produced liver enlargement. Light microscopic examination revealed hepatocellular hyperplasia, margination of basophillic cytoplasm, and foamy cytoplasmic alteration on the third day posttreatment. Laminated cytoplasmic inclusions developed seven days after treatment and subsequently disappeared about one week later. Under electron microscopy, the cytoplasmic margination corresponded to peripherally displaced granular reticulum and the foamy cytoplasm was recognizable as proliferating agranular reticulum with depletion of particualte glycogen. The cytoplasmic inclusions were identified as myelin configurations enclosing lipid bodies, membrane-bound vacuoles with whorled figures, and vesicular agranular reticulum. In the early developmental stages, the myelin figures were studded with ribosomes and associated with the granular reticulum.
