摘要:

The interaction of theFusariummycotoxins zearolenone and dihydrozearalanol with specific estrogen binding sites was studied by using cytosol preparations of mammary glands from lactating rats. Both substances inhibited [3H]estradiol‐17β association with its binding site in a competitive fashion. This inhibition was a result principally of an effect on estrogen binding by the 8S species of receptors separated by density gradient centrifugation. These data suggest that the biological action ofFusariummycotoxins with estrogenic activity is mediated by intracellular estrogen receptors.

ISSN:0098-4108    

DOI:10.1080/15287397809529638

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Adult male rats were given [14C]penicillic acid by oral intubation, and the biliary excretion of the compound was monitored. The significance of bile as an excretory route was confirmed and compared by using open and recycle cannulation of the bile duct. The biological half‐retention life of [14C]penicillic acid in the bile was 3.63 h.

ISSN:0098-4108    

DOI:10.1080/15287397809529639

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Exposure of mice to 50, 250, or 1000 ppm of vinyl chloride (VC) in the air for 6 h/d, 5 d/wk, caused a high incidence of bronchioloalveolar adenoma, mammary gland tumors, and hemangiosarcoma. Mammary gland tumors occurred in the females and included ductular odenocarcinoma and squamous and anaplastic cell carcinomas with metastasis to the lung. Hemangiosarcoma occurred in the liver and, to a lesser extent, in various other organs. The incidence and severity of these tumors increased with the concentration of VC and the length of exposure. Malignant lymphoma involving various organs was observed in several mice. Rats were more resistant to the carcinogenic effects of VC. Exposure of rats to 250 or 1000 ppm of VC caused hemangiosarcoma in the liver. Many rats with hepatic hemangiosarcoma also developed hemangiosarcoma in the lung. Extrahepatic hemangiosarcoma also occasionally occurred in other organs. Exposure to 55 ppm of vinylidene chloride (VDC) caused hepatic hemangiosarcoma and probably bronchioloalveolar adenoma in mice. Hemangiosarcoma also occurred in the mesenteric lymph node or subcutaneous tissue in two rats exposed to 55 ppm of VDC.

ISSN:0098-4108    

DOI:10.1080/15287397809529640

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Thousands of dyes and pigments are currently in use in the graphic arts and printing industry. Only a handful of these chromophores have been tested for carcinogenicity or mutagenicity, although many of them are members of chemical classes of compounds that include individual chemicals demonstrably carcinogenic in humans or in laboratory animals. A number of epidemiologic studies have demonstrated excess cancer in graphic arts personnel. The etiological agents have not been identified.

ISSN:0098-4108    

DOI:10.1080/15287397809529641

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Linear alkanes of specific chain length between 6 and 16 carbon atoms, an aryl derivative of dodecane, and a phorbol diester were tested in a cell culture system for relative ability to enhance mutagenesis induced by a chemical carcinogen, methyl‐azoxymethanol acetate (MAM). Mutation frequencies at the ouabain‐resistance locus were measured. Results indicated an excellent correlation between the relative activities of the above compounds in enhancing mutagenesis in thein vitroculture system and their tumor‐promoting activities in mouse skin. None of the compounds tested showed mutagenic activity per se, further lending support to the theory that promoters act via derepression of latent carcinogen‐induced damage to the genome.

ISSN:0098-4108    

DOI:10.1080/15287397809529642

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Adult mallard ducks fed 0, 1, 10, or 100 ppm vanadyl sulfate in the diet were sacrificed after 12 wk on treatment; tissues were analyzed for vanadium. No birds died during the study and body weights did not change. Vanadium accumulated to higher concentrations in the bone and liver than in other tissues. Concentrations in bones of hens were five times those in bones of drakes, suggesting an interaction between vanadium and calcium mobilization in laying hens. Vanadium concentrations in most tissues were significantly correlated and increased with treatment level. Lipid metabolism was altered in laying hens fed 100 ppm vanadium. Very little vanadium accumulated in the eggs of laying hens.

ISSN:0098-4108    

DOI:10.1080/15287397809529643

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Blood lead, erythrocyte glutathione reductase (GSSG‐R), 5‐aminolevulinic acid dehydratase (ALA‐D), and free sulfhydryl (SH) groups were measured in normal subjects and in those with occupational exposure to lead. With increasing blood lead concentration the activity of GSSG‐R rises and that of ALA‐D decreases. There is also a fall in the level of free SH with rising blood lead concentrations. There is a high degree of correlation between these parameters, and it is suggested that the changes represent part of a biological control mechanism to compensate for the reduction of available sulfhydryl groups by lead ions.

ISSN:0098-4108    

DOI:10.1080/15287397809529644

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

A bioassay capable of detecting carcinogenic substances that are associated with the elevated incidence of cancer in the urban environment would be important for epidemiologic and environmental analyses. The feasibility of using theSalmonellamutagenesis system developed by Ames for this purpose has been tested by analyzing Chicago air paniculate samples. Active material, as evidenced by enhanced rates of mutation, both in the presence of microsomes and in their absence, is readily extractable from samples of air particulates. Dose‐response curves have been obtained from such extracts of 15 successive samples, taken at intervals during 1975 from a sampling site in South Chicago. A method for analyzing such data in order to evaluate the relative mutagenic activity of different samples is described. The presence of a number of mutagenic constituents has been demonstrated by means of thin‐layer chromatography of particularly active samples, in which the active material is located by mutagenic analysis of successive chromatographic zones. Mass spectrometer analysis of material isolated from an original sample in this way indicates that benzo[a]pyrene and benzo[e]pyrene, which are known to be mutagenic and carcinogenic, are present. It is concluded that within certain constraints, which are described, the methodology can serve the purpose of an environmental bioassay for organic carcinogens.

ISSN:0098-4108    

DOI:10.1080/15287397809529645

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Thirteen chemicals, eight carcinogenic and five closely related noncarcinogenic analogues, were tested to establish the validity of a simultaneous procedure for thein vitroassay of potential carcinogens and mutagens. The assay utilizes Fischer rat embryo (FRE) cells infected with Rauscher leukemia virus and simultaneously measures the induction of cellular transformation (growth in soft agar) and mutagenesis (ouobain resistance) by chemicals. An activation procedure for the metabolic conversion of the procarcinogens and promutagens to biologically active forms is described. All chemicals that produced transformation in the FRE system also induced a significant increase in ouabain resistance. The significance and the potential uses of this assay are discussed.

ISSN:0098-4108    

DOI:10.1080/15287397809529646

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Single oral doses of ferbam, thlram, zineb, or maneb produced central nervous system stimulation followed by depression and alopecia. Ferbam and thiram were more toxic on the basis of weight than zineb; maneb was relatively nontoxic. There was no species difference in acute toxicity between rats and mice. In 13‐ and 80‐wk feeding studies, the toxic effects of ferbam and thiram in rats were similar; however, thiram was more toxic on the basis of weight than ferbam. During the 80‐wk feeding study, weight gain was reduced in ferbam‐treated rats starting at daily doses of 8 mg/kg in males and 37 mg/kg in females and in thiram‐treated rats starting at daily doses of 5 mg/kg in males and 26 mg/kg in females. Food consumption was reduced in proportion to the reduced weight gain. Death occurred in males fed 109 or 331 mg/kg. ferbam and in males fed 58 or 132 mg/kg. thiram. Female rats fed 96 mg/kg. ferbam or 67 mg/kg. thiram developed alopecia and ataxia, which led to paralysis of the hind limbs. Male rats fed ferbam or thiram had a more severe incidence of squamous metaplasia in the thyroid and fatty infiltration in the pancreas than control males. Ferbam or thiram reduced the incidence of spontaneous nephritis in both males and females. The male rats that were fed 109 or 331 mg/kg. ferbam and died between 1 and 5 wk had golden pigment in the reticuloendothelial cells of the spleen and in the enlarged mesenteric lymph nodes, associated with hemosiderosis. Moderate tubular degeneration of the testes with atypical spermatids in the epididymis occurred in some rats fed 132 mg/kg. thiram for 13 wk but not in rats fed up to 52 mg/kg. for 80 wk. Periodic hematologic examination and terminal clinical blood tests did not reveal any severe changes. Ferbam and thiram did not alter the occurrence or latent period of the spontaneous tumors seen in control rats.

ISSN:0098-4108    

DOI:10.1080/15287397809529647

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor