摘要:

AbstractWhile 2‐nitronaphthalene was a weak direct‐acting base‐substitution mutagen (1.4 revertants/nanomole) for Salmonella typhimurium, the analogous nitronaphthalic acid anhydride and imides were moderate frameshift mutagens (∼20 rev/nanomole in strain TA98). Although imide derivatives are efficient DNA intercalators, mutagenicity data indicate that the bulk of the frameshift activity is derived from adduct formation between hydroxylamine intermediates and DNA. The low level of frameshift activity (∼8% of total) resulting from simple intercalation (measured in strain TA1537) is not dependent upon reduction of the nitro function.Evidence is presented that suggests that the reduction of the nitro function to the corresponding hydroylamine might not involve a free nitroso intermediate.The introduction of a second nitrofunction into nitronaphthalenes results in great positional effects of the various isomers on mutagenic activity and sp

ISSN:0192-2521    

DOI:10.1002/em.2860030502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractUnstimulated human lymphocytes in whole blood were treated for three hours with lead, cadmium, and zinc acetate separately and in combinations of two or three metal salts with different concentrations of between 10−3and 10−8moles, respectively. Untreated cultures and sodium acetate‐treated samples served as controls. Chromosome analysis from 48 cultures revealed higher incidences of chromatid‐type aberrations and gaps only for cultures exclusively treated with cadmium. The results are discussed under the aspect of heavy metal metabolism in human lymp

ISSN:0192-2521    

DOI:10.1002/em.2860030503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractWe have studied the mutagenicity of the water from Lake Bloomington and of the tap water that is made from the lake water. The lake, which is the source of drinking water for Bloomington, Illinois (pop. 44,000), is surrounded by land that is farmed intensively ‐ being mainly in maize and soybeans. Samples were collected monthly from May through October 1979 and concentrated 3,000× with XAD‐2 resin. Nearly all of the lake and tap water concentrates were mutagenic in Salmonella typhimurium TA98 and TA100 in the presence of S‐9 mix, and the May tap water concentrate was highly mutagenic. In addition, many of the concentrates were toxic to the bacteria in the absence of S‐9 mix. Chemical analysis of the highly mutagenic tap water concentrate from May revealed the presence of a number of organic contaminants that were absent from control concentrates prepared from deionized and distilled treated well water. In addition, unconcentrated lake and tap water were tested in a reverse‐mutation test in maize (Zea mays); no mutagenicity was detected. This study indicates that the contamination of drinking water with agricultural and/or industrial chemicals may result in a potential hea

ISSN:0192-2521    

DOI:10.1002/em.2860030504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractLymphocyte culture systems have the major advantage of permitting the analyssis of in vivo cytogenetic damage with minimal injury to the animal under study. This paper describes a rat lymphocyte culture system designed for the study of sister chromatid exchange (SCE) induced by in vivo exposure to genotoxic agents. A standard protocol was established in which 1 to 2 ml of blood are removed from rats by cardiac puncture, washed three times with phosphate‐buffered saline (pH 7.4), and grown in RPMI 1640. 5‐Bromodeoxyuridine (BrdU) (1.0 μM) is added after 24 hr, and cells are harvested after 56 hr of culture. Critical steps for successful blast transformation include washing the blood in buffered saline and the adding of 2.0 to 4.0 μg phytohemagglutinin/ml to the culture medium. The use of low concentrations of BrdU (≤5.0 μM) is recommended to maintain low baseline SCE levels and to avoid cytotoxicity. The mutagenic carcinogen, ethyl methanesulfonate (EMS), was used as a positive control agent and at a dose of 300 mg/kg caused a fourfold increase in SCE frequency. Twenty‐eight days after EMS administration (30, 100, 300 mg/kg), lymphocytes from treated animals still displayed SCE levels at least 50% above baseline. This system provides a reliable means of investigating chemically induced SCE

ISSN:0192-2521    

DOI:10.1002/em.2860030505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractSeveral metals are known mutagens and carcinogens. These metals effectively displace acridine orange from DNA when measured by fluorescence polarization. Displacement of 50% of the acridine orange is obtained with less than 0.5 mM concentrations of lead, manganese, cobalt, zinc, cadmium, nickel, iron, copper, and cis‐platinum. In contrast, greater than 80 mM concentrations of lithium, sodium, and potassium are required to displace an equivalent amount of acridine orange from calf thymus DNA. Although cis‐platinum shows the best DNA reactivity in this assay, the interaction between this metal and DNA does not occur immediately, as it does for the other metals tested. These results indicate that the acridine orange displacement assay provides a relative measure of the interaction of metals with DNA, and this DNA reactivity shows a positive correlation with mutagenic/carcinogenic potent

ISSN:0192-2521    

DOI:10.1002/em.2860030506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractCis‐Diamminedichloroplatinum (II), an antitumor compound which exhibits mutagenic activity, and its degradation products platin B salt, magnus red, and magnus red anion salt were tested in the Ames microbial mutagenicity assay. The purpose of this investigation was to determine if the positive mutagenic response of the platinum compound could be due to, or enhanced by, the presence of degradation products. Results indicate that platinum degradation complexes are weak mutagens which are capable of inducing both base pair and frameshift‐type mutati

ISSN:0192-2521    

DOI:10.1002/em.2860030507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractGamma‐irradiation was effectively employed to sterilize rat liver postmito‐chondrial supernant (PMS), which is required for the metabolic activation of soots and soot‐derived polycyclic aromatic hydrocarbons to mutagens. When a known number of Bacillus subtilis spores were added to the PMS and gammairradiated at −80° C, a 2‐Mrad dose resulted in a 7.5 log kill of the spores. A dose of 3 Mrads was selected as a sufficient effective sterilizing dose and had no significant effect upon the ability of gamma‐irradiated PMS to metabolically activate diesel soot and two diesel soot components, benzo(a)pyrene and fluoranthene to mutagens in a Salmonella typhimurium 8‐azaguanine resistance forward mutation assay. Three Mrads of gamma‐irradiation also had no effect upon the ability of PMS to activate benzo[a]pyrene to a mutagen for the human lymphoblasts. However, gamma‐irradiation did reduce the ability of PMS to activate dimethylnitrosamine to a mutagen

ISSN:0192-2521    

DOI:10.1002/em.2860030508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractWeighted least squares estimation is used for fitting nonlinear models to Ames test data. The models are biologically plausible, incorporating mutagenicity, toxicity, and/or saturation. Regressions are weighted to compensate for variance that changes with mean and to attain outlier resistance.

ISSN:0192-2521    

DOI:10.1002/em.2860030509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

ISSN:0192-2521    

DOI:10.1002/em.2860030510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

ISSN:0192-2521    

DOI:10.1002/em.2860030511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY