摘要:

Shale oil retort water, a by‐product of the production of oil from shale, potentially amounts to tens of millions of gallons per year and must be treated or recycled with regard for public health. Such retort water was given to 98 female ICR/DUB mice in their drinking water at concentrations of 0, 0.1, 0.3, and 1.0% for periods up to 203 d. Seven of 75 treated animals developed adenomalike lesions that were not seen in the control animals. These ranged from adenomas and an adenomatoid nodule in the lung to a rectal adenocarcinoma. Although the incidence of adenomalike lesions was not statistically significant, this appearance of neoplasia requires further investigation.

ISSN:0098-4108    

DOI:10.1080/15287398109530115

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Gases formed by rubber and rubber additives in the vulcanization process were collected with a laboratory‐scale glass apparatus. Mutagenicity testing of the vulcanization gases by the Salmonella/microsome test was conducted with strains TA1535, TA1538, TA98, and TA100 in the absence and presence of a metabolizing system from rat liver homogenates. The mutagenicity of gases derived by heating chloroprene rubber and ethylene propylene rubber was established with both base substitution‐ and frameshift‐sensitive strains and that of a styrene‐butadiene rubber was established with the base substitution‐sensitive strain TA100. Tests on pyrolysis gases from a butadiene acrylonitrile rubber revealed only toxic effects. Curing systems, additives, and filling materials from various sources were represented in the material. Gases were collected at temperature levels corresponding to both mixing and curing of these particular rubbers in the industrial operations. Attempts were made to correlate the mutagenicity of the gases to the presence of mutagenic components in the rubber mixtures.

ISSN:0098-4108    

DOI:10.1080/15287398109530116

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Male C57BL/6 mice were given feed containing various concentrations of 2,4‐dichlorophenoxyacetic acid (2,4‐D), 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T), and 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) to provide daily doses of approximately 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 2.4 μg/kg TCDD (group II); 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 0.16 μg/kg TCDD (group III); and 20 mg/kg 2,4‐D, 20 mg/kg 2,4,5‐T, and 1.2 μg/kg TCDD (group IV). The chemical mixtures were chosen to approximate the concentrations of the components of Herbicide Orange. Controls (group I) were given a diet with only the corn oil vehicle added to the feed. In the treated animals, liver enlargements, hepatocellular toxicity, and reduced thymus size were found and body weight gain was significantly less than that of the control animals. Significant or complete recovery from liver and thymus toxicity was observed when the mice were returned to a control diet. The thymic toxicity and hepatotoxicity seemed to be related to TCDD levels, while the decrease in body weight gain was more closely associated with phenoxy acid concentrations. All effects attributed to the mixture were elicited by individual compounds in the mixture in previous studies.

ISSN:0098-4108    

DOI:10.1080/15287398109530117

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Fertility and sperm number, motility, and morphology were analyzed in male C5 7BLJ6 mice exposed to various mixtures of 2,4‐dichlorophenoxyacetic acid (2,4‐D), 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T), and 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) in the diet for 8 wk. Somatic cell (bone marrow) sister chromatid exchange frequencies were also evaluated in mice injected with similar chemical mixtures. The concentration of the test chemicals was such that the average daily feeding dose in the three mixtures or control was 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 2.4 μg/kg TCDD; 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 0.16 μg/kg TCDD; 20 mg/kg 2,4‐D, 20 mg/kg 2,4,5‐T, and 1.2 μg/kg TCDD; or no chemical added (control). No significant dose‐related effects were observed in the treated mice compared to the control group.

ISSN:0098-4108    

DOI:10.1080/15287398109530118

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Male C57BL/6 mice were given feed containing various concentrations of 2,4‐dichlorophenoxyacetic acid (2,4‐D), 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T) and 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) such that their diets contained daily doses of approximately 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 2.4 μg/kg TCDD (group II); 40 mg/kg 2,4‐D, 40 mg/kg 2,4,5‐T, and 0.16 μg/kg TCDD (group III); or 20 mg/kg 2,4‐D, 20 mg/kg 2,4,5‐T, and 1.2 μg/kg TCDD (group IV). Controls (group I) were given a diet with only the corn oil vehicle added to the feed.

ISSN:0098-4108    

DOI:10.1080/15287398109530119

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The distribution and excretion of hexachlorobenzene (HCB) after administration to quails of a single oral dose of 4.5 Ci[14C]HCBper l00g body weight was studied by whole‐body autoradiography and liquid scintillation counting. Radiolabeled HCB was distributed throughout the body in 2 h. Peak levels were found 4–8 d after administration, with the highest concentrations in the subcutaneous and abdominal fat, uropygialgland, bone marrow, adrenals, ovarian stroma, and liver, in that order. After 3 wk, substantial amounts of radiolabeled substance were present only in the adipose tissue and the uropygial gland. The main routes of excretion were the egg yolk, uropygial gland, and bile. About 75% of the administered dose was excreted through the egg yolk and about 25% in the feces.

ISSN:0098-4108    

DOI:10.1080/15287398109530120

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The pathogenesis of NO2‐induced respiratory disease and the effect of NO2on respiratory clearance ofs1Cr2Oiwere studied. Young adult female mice were exposed to a 51Cr2O3aerosol, followed by a daily exposure to either 30 ppm NO2for 2 wk or 60 ppm NO2for 2 wk or a single exposure to 170 ppm NO2. Exposure to 30 ppm NO2had a minimal histopathologic effect on respiratory tract tissue. Exposure to 60 ppm NO2produced marked histopathologic effects, which were subsequently resolved. Exposure to 170 ppm NO2produced permanent histopathologic lesions.

ISSN:0098-4108    

DOI:10.1080/15287398109530121

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Treatment of newborn rat pups with 60 mg/kg‐d chlorphentermine for 7 d produced an accumulation of alveolar foam cells accompanied by an increase in relative pulmonary tissue weight. In contrast, administration of 20 mg/kgd for 1 wk did not markedly alter lung ultrastructure or weight in newborns. Both doses of chlorphentermine elevated the activity of pulmonary aminopyrine N‐demethylase but not that of aniline hydroxylase. The Increase in relative liver weight was associated with stimulation of the activities of aniline hydroxylase and aminopyrine N‐demethylase in newborns administered either chlorphentermine dose. Phenobarbital treatment produced an increase in relative liver weight accompanied by elevated activities of pulmonary aminopyrine N‐demethylase and hepatic aniline hydroxylase and aminopyrine N‐demethylase. Simultaneous barbiturate and chlorphentermine administration produced stimulation in liver enzymes to the same extent as phenobarbital alone. In contrast, phenobarbital potentiated the chlorphentermine‐induced rise in pulmonary aminopyrine H‐demethylase. In the case of 60 mg/kg chlorphentermine and barbiturate, the observed potentiation of lung enzyme activity was associated with a reduction in the number of alveolar foam cells. The results suggest that chlorphentermine and phenobarbital stimulate drug‐metabolizing enzymes in lung and liver of newborn rats and that phenobarbital may provide protection against phospholipidosis through stimulation of pulmonary drug‐metabolizing enzymes.

ISSN:0098-4108    

DOI:10.1080/15287398109530122

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Oral doses of the organophosphorus pesticides acephate, dicrotophos, fensuifothion, fonofos, malathion, and parathion were administered to mallard ducklings (Anas platyrhynchos), and brain and plasma cholinesterase (ChE) activities were determined for up to 17 d after dosing. In vivo recovery of brain ChE activity to within 2 standard deviations of the mean activity of undosed birds occurred within 8 d, after being depressed an average of 25–58% at 24 h after dosing. In vivo recovery of plasma ChE appeared as fast as or faster than that of brain, but the pattern of recovery was more erratic and therefore statistical comparison with brain ChE recovery was not attempted. In vitro tests indicated that the potential for dephosphorylation to contribute to in vivo recovery of inhibited brain ChE differed among chemical treatments.

ISSN:0098-4108    

DOI:10.1080/15287398109530123

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The effect of aspirin on experimentally induced atherosclerosis was studied in rabbits. Rabbits were placed on an atherogenic diet containing either no aspirin or 0.2% aspirin supplement Control rabbits were fed regular rabbit food or rabbit food supplemented with 0.2% aspirin. Ingestion of aspirin from the diets containing aspirin was equivalent to a daily dose of 100 mg/kg. As expected, 2 mo after the rabbits were placed on the atherogenic diet, extensive atheromatous lesions were observed on gross examination sporadically distributed along the walls of the aorta. The coronary arteries also exhibited atheromatous lesions on microscopic examination. Addition of aspirin to the atherogenic diet intensified the atherosclerosis as measured by proliferation of the intima of the aorta and coronary arteries and increased occurrence and distribution of atheromatous plaques. It is concluded that, under the conditions of this experiment, the addition of aspirin to an atherogenic diet greatly intensified atherogenesis.

ISSN:0098-4108    

DOI:10.1080/15287398109530124

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor