摘要:

Mice were injected intratracheally with silica or Mt. St. Helens volcanic ash (0.2 mg/g body weight) and examined 6 mo later for changes in pulmonary function, histology, and hydroxyproline content. Results were compared with a similar study using rats. Mice injected with volcanic ash showed significant changes only in wet lung weights. Those injected with silica showed an approximate doubling of lung wet weight and dry weight and hydroxyproline content. Larger increases in lung weight were seen if lymph nodes were left attached. Lung compliance, total lung capacity, and the shape of the pressure‐volume curve of the lung were changed as much as 22% in the silica‐treated mice. A mild degree of fibrosis with no dense lung consolidation was noted microscopically in silica‐treated mice. In contrast, silica‐treated rats showed dense lung consolidation, threefold to fivefold increases in both wet and dry lung weights and hydroxyproline content, and up to 40% reductions in pulmonary function measurements. It is concluded that Swiss albino mice develop a milder degree of fibrosis than similarly treated Sprague‐Dawley rats and that both biochemical and functional indicators are effective in detecting pneumoconiosis in these species.

ISSN:0098-4108    

DOI:10.1080/15287398409530514

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An integrated water‐insoluble chemical delivery/metabolic activation/rat embryo culture system is described. Increasing concentrations of diallate dissolved in corn oil caused dose‐related embryonic growth retardationin vitro. The presence of a metabolic activating system did not potentiate the effects of diallate in corn oil. The rat hepatic microsomal monooxygenase system was enzymatically active in the presence of a high concentration of corn oil in the rat serum incubation media. Thus, the failure of the metabolic activation system to potentiate the toxicity of diallate in corn oil is not due to an enzymatic deficiency of the hepatic metabolic activation system. As high concentrations of some organic solvents are known to act directly as embryonic poisonsin vitro, rat embryos were cultured in incubation media that contained chloroform (0.5 or 2.5%) dissolved in corn oil. This treatment was found to be severely toxic to embryonic growth and differentiationin vitro. Thus, unlike diallate, the embryonic toxicity of chloroform was fully evident when dissolved in the solvent corn oil. Diallate dissolved in acetone retarded embryo growth and caused dysmorphogenesis. When a metabolic activation system and either corn oil or acetone were used together, the incidence of embryolethality and abnormalities were so high that compound treatment effects were difficult to evaluate.

ISSN:0098-4108    

DOI:10.1080/15287398409530515

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The acute toxic action of a number of common chemicals was tested by their ability to cause detachment of cultured mouse neuroblastoma C1300 cells. A TD25 value was obtained by graphic estimation of the concentration needed to cause 25% of the total cell number to detach. These TD25 values were compared with LD50 values obtained from the literature, and they were found to correlate with a coefficient of 0.86. For six of the tested substances—diuron, butylated hydroxytoluene, benzidine, cyclophosphamide, Na2SeO3, and KCN‐a very poor correlation was obtained. These diverging results could be ascribed to deficiencies in the neuroblastoma cell detachment test and emphasize the necessity for combinedin vitrotest procedures.

ISSN:0098-4108    

DOI:10.1080/15287398409530516

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Seven coumarin derivatives (imperatorin, heraclenin, xanthotoxin, marmesin, chelepin, oxypeucedanin, esculin) and a furan derivative (nimbolide) were screened on 6 Ames tester strains (TA92, TA94, TA97, TA98, TA100, TA102). The eight compounds are chemicals isolated from three Nigerian medicinal plants:Afraegle paniculata, Clausena anisata, andAzadirachta indica. Different preparations of the former are taken by Nigerians for gut disturbances, and a concoction of the latter called “Agbo” is taken as an antimalarial.

ISSN:0098-4108    

DOI:10.1080/15287398409530517

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A fuel‐oil blend (FOB) and its hydrotreated product from the solvent‐refined coal (SRC) II process were evaluated for their mutagenic and carcinogenic potential. The FOB was highly active in both cellular assays, as well as in animal (skin‐painting) studies. Cell‐transforming and mutagenic activities of hydrotreated FOB were consistently found to be lower than for untreated FOB. Finally, while most of the initiating activity (in the animal assay) was lost following hydrotreatment, the data indicate that the hydrotreated FOB still had significant skin‐tumor‐promoting activity.

ISSN:0098-4108    

DOI:10.1080/15287398409530518

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Concentrations of total and vertical elutriated airborne dusts were quantified for five work areas within a rice production commune near Shanghai, the People's Republic of China. Mean (±SE) commune levels of 15.69 ± 1.91 mg/m3and 6.00 ± 1.47 mg/m3were found for total and vertical elutriated dusts, respectively. Analysis of the airborne dusts for the presence of gram‐negative bacterial endotoxins resulted in mean levels of 21.23 ± 8.63 ng/mg total dust and 14.57 ± 7.97 ng/mg elutriated dust, with respective airborne concentrations of 492.12 and 100.22 ng endotoxin/m3. These data show that rice production in the People's Republic of China is associated with a dust burden that is contaminated with relatively high levels of endotoxins. The long‐term respiratory effects of inhalation of these dusts should be studied.

ISSN:0098-4108    

DOI:10.1080/15287398409530519

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Ochratoxin A (OA) and citrinin (CT) are food‐borne mycotoxins produced by several fungal species of the generaAspergillusand Penicillium. Both are teratogenic in the rat. To determine the prenatal effects of simultaneous exposure to these toxins, pregnant Sprague‐Dawley rats were injected either with a single individual subthreshold teratogenic dose of OA (1 mg/kg) or CT (30 mg/kg) or with both toxins. Toxins were dissolved in 5% sodium bicarbonate and administered subcutaneously on one of gestation d 5, 6, 7, 8, 10, 11, or 14. Maternal body weight gain of animals in the combination group was similar to other treatment groups and the control. Approximately 22–40% mortality in dams occurred on gestation d 5, 6, 7, and 14. Other than d 7, there was no significant effect on the number of implants. Treatment on d 5 or 7 resulted in increased fetal resorptions. Fetal body weights were not decreased significantly. OA and CT in combination resulted in a significant increase in gross malformations on d 6 and 7, visceral anomalies on d 5, 7, 8, and 10, and skeletal defects on d 5, 6, 7, 8, 10, and 14. When administered individually, OA and CT resulted in very few fetal résorptions. Fetal body weights were not significantly different except on d 8 of gestation following CT treatment. Individual toxin treatment resulted in minimal malformations on all gestation days. These results suggest that OA and CT, when administered concurrently, may interact to enhance prenatal toxicity and teratogenicity, and these results have focussed attention on the public health hazards of contamination of food with these mycotoxins.

ISSN:0098-4108    

DOI:10.1080/15287398409530520

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The LD50 (7 d) for aflatoxin B1(AFB1) in CD‐1 neonate mice (3.7 g; 5 d of age) was determined to be 13.3 mg/kg. The vehicle was dimethyl sulfoxide (DMSO), given intra‐peritoneally, at 0.01 ml/animal (7 mg/kg). The solvent was nontoxic and caused no significant change in body weight in animals during an 11‐d experimental period (17 d of age). Aflatoxin B1at 5.0 mg/kg and above caused reduced body weight gain. DMSO animals had a mean loss of more than 17% of the radiolabel over a 9‐d period. Aflatoxin treatments reversed the DMSO loss of54Mn in a concentration‐related fashion, and generally, AFB1caused a conservation of the radioisotope. The radiolabel was redistributed into the following organs/tissues: liver > brain > bone > muscle = lungs > blood. Aflatoxin‐treated animals showed a twofold increase of radiolabel in the liver as compared to controls. The DMSO itself failed to influence54Mn influx into the liver. In general, control neonate mice, by 17 d of age, were retaining and redistributing the54MnCl2and had not reached the time for sudden emergence of excretion common in rodents. DMSO was found not to be the most satisfactory solvent to use in the administration of aflatoxins, especially when manganese metabolism is being studied. Generally, both DMSO and AFB1influenced radiomanganese distribution, DMSO having a substantial influence.

ISSN:0098-4108    

DOI:10.1080/15287398409530521

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Induction of resistance to aflatoxin B1(AFB1) binding to cellular macromolecules in the rat by chronic exposure to AFB1and aflatoxin M1(AFM1) was investigated. The binding of [14C]AFB1to liver macromolecules was measured in F‐344 rats fed 0.5 ppb or 50 ppb AFM1or 50 ppb AFB1for 41 wk. The animals then received an intragastric dose of [14C]AFB1at 5 μg/kg and were sacrificed 6 h later. Hepatic DNA, RNA, and protein were isolated by chloroform‐phenol extraction and hydroxylapatite chromatography. In animals preexposed to 50 ppb AFB1, labeled AFB1binding to DNA, RNA, and protein was decreased by 72%, 74%, and 61%, respectively. Preexposure to AFM1resulted in a small reduction in binding to nucleic acids. Glutathione trans‐ferase activity was increased by 133% in animals fed 50 ppb AFB1, by 48% in those preexposed to 50 ppb AFM1, and remained at control values in rats fed 0.5 ppb AFM1. These results suggest that the induction of detoxification enzymes following chronic exposure to aflatoxin might contribute to the reduction in covalent binding of AFB1to macromolecules.

ISSN:0098-4108    

DOI:10.1080/15287398409530522

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Bulk dust samples obtained from grain elevators in the central Illinois area were analyzed for aflatoxin (AFT) content using instrumental two‐dimensional high performance thin‐layer chromatography (HP‐TLC). AFT B1levels ranged from nondetect‐able up to 3.5 ppb. This is the first report of AFT occurring in dust in northern grain mills. Long‐term exposures of workers to AFT contaminated dust via the respiratory route could pose some hazard.

ISSN:0098-4108    

DOI:10.1080/15287398409530523

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor