bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the genotoxic activities of extracts from ambient and forest fire polluted air
Authors: Viau C. J. , Lockard J. M. , Enoch H. G. , Sabharwal P. S. 
Published: February 2007

AbstractThe genotoxicity of airborne organic particles from forest fire smoke was compared to that from nonsmoky (ambient) urban air using the Salmonella reversion assay and the sister chromatid exchange (SCE) assay in cultured human lymphocytes. Salmonella strains TA98 and TA100 were used with and without the addition of Aroclor‐induced rat liver homogenate (S9). Each sample induced dose‐related increases in mutagenicity and SCE. However, on the basis of the volume of air sampled, the smoke‐filled air induced 12 to 14 times more bacterial reversions in TA100 and 16–38 times more reversions in TA98 than ambient air. Similarly, on a volume basis smoky air induced 43 times more SCE in human lymphocytes than did ambient air. The results indicate that the increased mutagenicity was due not only to the heavier particulate load of the air, but also to the increased specific mutagenicity of the particles.
A comparison of induced sister chromatid exchange levels in chinese hamster ovary cells and cultured human lymphocytes
Authors: Morgan William F. , Crossen Peter E. 
Published: February 2007

AbstractHuman lymphocytes and Chinese hamster ovary cells were exposed to DNA damaging agents for two cell cycles, and the induced sister chromatid exchange (SCE) rate was compared. CHO cells showed a significant increase in SCE following treatment with bleomycin and vincristine whereas human lymphocytes did not. Both CHO cells and lymphocytes showed an increase in SCE with 5‐bromode‐oxyuridine (BrdUrd) and tritiated uridine (3H‐Urd) but the increase was greater in CHO cells. SCE levels were similar after exposure to proflavine and colcemid did not increase the exchange frequency in either cell type. Apparently CHO cells are more sensitive than human lymphocytes to the actions of bleomycin, vincristine, BrdUrd, and 3H‐Urd. SCE analysis in response to mutagens and carcinogens should therefore be based on more than one cell type.
Metabolic activation of 3‐methylcholanthrene and benzo(a)pyrene to mutagens in the L5178Y/TK assay by cultured embryonic rodent cells
Authors: Amacher David E. , Paillet Simone C. , Zelljadt Inna 
Published: February 2007

AbstractEarly passage cultured rodent cells obtained from mouse, rat, or Syrian hamster embryos were cocultivated with L5178Y/TK+/‐ cells in the presence of benzo(a)pyrene (B(a)P) or 3‐methylcholanthrene (3MCA) for 6 hr to determine if active metabolic intermediates could be detected in this cell‐mediated assay through the induction of TK+/‐ mutants. Neither chemical was directly active as a mutagen when tested with L5178Y/TK+/‐ cells alone. As a mutagen, 3MCA was slightly active in the presence of mouse or rat embryo cells and clearly active when tested with hamster embryo cells. B(a)P was active only in the presence of hamster embryo cells when tested at concentrations that would be mutagenic in the presence of rodent liver microsomal preparations. These results indicate the utility of L5178Y/TK+/‐ plus hamster embryo cell combinations in a cell‐mediated mutation assay for the detection of these two polycyclic hydrocarbon carcinogens.
Sister chromatid exchanges induced in rabbit lymphocytes by ethylene oxide after inhalation exposure
Authors: Yager Janice W. , Benz R. Daniel 
Published: February 2007

AbstractEthylene oxide, which is the simplest epoxide and an extremely important commercial compound, has been used by many investigators as a model compound to study mutagenicity by alkylation of DNA. Knowledge of in vivo dose‐effect relations under experimental conditions may provide further insight into the dynamics of the sister chromatid exchange (SCE) response. It may also provide information on temporal aspects of sampling design for human worker populations. Groups of four male New Zealand white rabbits were exposed in inhalation chambers to 0, 10, 50, and 250 parts per million (ppm) ethylene oxide for 6 hr a day, 5 days a week, for 12 weeks. Peripheral blood samples were taken before the start of exposure, at intervals during exposure, and up to 15 weeks after the end of exposure to measure SCE rates in peripheral lymphocytes as well as standard hematological endpoints. Additionally, the level of reduced glutathione (GSH) in liver and blood was measured in a set of concurrently exposed animals at the end of the 12‐week exposure. Results show that exposure to 10 ppm does not cause a detectable increase in SCE rates. However, exposure to 50 and 250 ppm does cause an increase in SCEs that decreases after exposure ends, but still remains above baseline levels 15 weeks after exposure. Hematological and GSH measurements did not differ between control and exposed groups. These results indicate that inhalation exposure to the mutagenic alkylating agent ethylene oxide results in a dose‐related SCE effect, and that SCE is a more sensitive indicator of exposure than either standard hematological end points or GSH levels.
Mutagenicity in salmonella typhimurium and structure‐activity relationships of wastewater components emanating from the manufacture of trinitrotoluene
Authors: Spanggord Ronald J. , Mortelmans Kristien E. , Griffin Ann F. , Simmon Vincent F. 
Published: February 2007

AbstractThe mutagenicity of 36 polynitroaromatic compounds was investigated with five strains of Salmonella typhimurium. Isomeric trinitrotoluenes (TNT), with the exception of 2,4,6‐TNT and 2,3,4‐TNT, exhibit mutagenicity independently of nitroreductase enzymes, but isomeric aminodinitrotoluenes (ADNT) and isomeric dinitrotoluenes (DNT) need nitroreductase to induce mutation. Within groups of isomeric TNTs, DNTs, and ADNTs, mutagenic response was enhanced by a para orientation of nitro groups. The mutagenic response of isomeric DNTs was found to correlate with the compound's ability to undergo charge‐transfer complexation with reductive enzymes, whereas further complexation (such as a Janovsky complex) appears to be required for inducing mutation in dinitrobenzenes. These results indicate that polynitroaromatic compounds in TNT wastewaters possess a significant potential for biologic activity.
Induction of sister chromatid exchanges and inhibition of cellular proliferation in vitro. I. caffeine
Authors: Guglielmi Gwen E. , Vogt Thomas F. , Tice Raymond R. 
Published: February 2007

AbstractCytogenetic assay systems based on the detection of sister chromatid exchanges (SCE) are widely advocated as a sensitive screening method for assessing genotoxic potential. While many agents have been examined for their ability to induce SCE's, complete dose‐response information has often been lacking. We have reexamined the ability of one such compound — caffeine — to induce SCEs and also to inhibit cellular proliferation in human peripheral lymphocytes in vitro. An acute exposure to caffeine prior to the DNA synthetic period did not affect either SCE frequency or the rate of cellular proliferation. Chronic exposure to caffeine throughout the culture period lead to both a dose‐dependent increase in SCEs (SCEd or doubling dose = 2.4 mM; SCE10 or the dose capable of inducing 10 SCE = 1.4 mM) and a dose‐dependent inhibition of cellular proliferation (IC50 or the 50% inhibition concentration = 2.6 mM). The relative proportion of first generation metaphase cells, an assessment of proliferative inhibition, increased linearly with increasing caffeine concentrations. However, SCE frequency increased nonlinearly over the same range of caffeine concentrations. Examination of the ratio of nonsymmetrical to symmetrical SCEs in third generation metaphase cells indicated that caffeine induced SCEs in equal frequency in each of three successive generations. The dependency of SCE induction and cellular proliferative inhibition on caffeine's presence during the DNA synthetic period suggests that caffeine may act as an antimetabolite in normal human cells. The significance of these results in regard to both caffeine's genotoxic potential and to the reliability of the SCE assay system are discussed.
Mithramycin‐ and triethylene melamine‐induced sperm abnormalities in lakeview hamsters
Authors: Singh H. , Newton Deborah 
Published: February 2007

AbstractThe sperm abnormality‐inducing action of two potential mutagenic agents, mithramycin and triethylene melamine (TEM), in inbred Lakeview hamsters was studied and results compared with similar investigations in mouse. Test hamsters received subacute intraperitoneal exposures ranging from 0.01 to 0.25 mg/kg body weight with either agent for 5 consecutive days. Testis weights, epididymal sperm numbers, and body weights were also monitored at weeks 1, 4, and 10 after treatment. Mithramycin‐treated hamsters showed 21 times more sperm abnormalities than control (25% vs. 1.2%) whereas TEM elevated sperm abnormalities by eight fold. The frequency and type of aberrant sperm varied with dose and time, being the highest at weeks 1 or 4, rather than week 10, with either agent. Sperm number and testis weights remained depressed considerably from 4 to 10 weeks after treatment with either agent. Body weights in chemically treated hamsters remained within 28% of control for the test period. Even though our findings were in general agreement with those reported for mouse, the magnitude of the response and the stage of spermatogenic sensitivity in the chemical induction of sperm abnormalities in the two species were different.
Microbial detection of mutagenic nitro‐organic compounds in filtrates of coal fly ash
Authors: Wei Cheng‐I , Raabe Otto G. , Rosenblatt Leon S. 
Published: February 2007

AbstractThe presence of mutagenic nitro‐organic compounds on coal fly ash was indicated by the greatly reduced microbial mutagenicity of the ash filtrates with nitroreductase‐deficient strains of Salmonella typhimurium compared to their corresponding parental strains. Addition of the liver S‐9 microsomal enzyme preparation significantly increased the mutagenic activities of the ash extracts. Extracts of fly ash mutagens were prepared with horse serum, dimethyl sulfoxide, or azeotropic benzene/methanol mixture. The data were normalized to net revertants per 108 Salmonella typhimurium cells per milligram of ash used. This normalization procedure is essential for interpretation of comparative results. Both four‐way and three‐way analyses of variance were used to simultaneously evaluate the differences between solvent extracts, fly ash mutagen, S‐9 activation, and nitroreductase‐deficient strains and their parental strains. Of the three extraction systems tested, benzene/methanol azeotropic mixture was generally found to have the highest extraction power, and horse serum was the lowest. The results show that overall 87.5% (± 1.8 SE) of the mutagenic activity of the fly ash was associated with nitro‐organic compounds.
Structure‐activity studies on the mutagenicity of tris(2,3‐dibromopropyl) phosphate (tris‐BP) and its metabolites in salmonella
Authors: Zeiger Errol , Pagano Dennis A. , Nomeir Amin A. 
Published: February 2007

AbstractA series of methylated metabolites of the flame retardant tris(2,3‐dibromopropyl) phosphate (Tris‐BP) were tested for mutagenicity in Salmonella, along with the parent chemical and other structurally related chemicals. The metabolites produced a gradient of mutagenic responses in TA1535 in the same dose range and up to the same magnitude as the Tris‐BP response. None of the metabolites tested appeared to be the ultimate mutagen, since they all required S‐9 for their mutagenic activity.
Cytotoxic and mutagenic properties of shale oil byproducts II. Comparison of mutagenic effects at five genetic markers induced by retort process water plus near ultraviolet light in chinese hamster ovary cells
Authors: Chen David Jen‐Chi , Strniste Gary F. 
Published: February 2007

AbstractA chinese hamster ovary (CHO) cell line heterozygous at the adenine phosphoribosyl transferase (APRT) locus was used for selection of induced mutants resistant to 8‐azaadenine (8AA), 6‐thioguanine (6TG), ouabain (OUA), emetine (EMT) and diphtheria toxin (DIP). The expression times necessary for optimizing the number of mutants recovered at the different loci have been determined using the know direct acting mutagen, far ultraviolet light (FUV), and a complex aqueous organic mixture (shale oil process water) activated with near ultraviolet light (NUV). Our results indicate that optimal expression times following treatment with either mutagen was between 2 and 8 days (depending on the genetic marker examined). For CHO cells treated with shale oil process water and subsequently exposed to NUV a linear dose response for mutant induction was observed for all five genetic loci. At 10% surviving fraction of cells, between 35‐ and 130‐fold increases above background mutation frequencies were observed for the various markers examined. Among the five genetic loci tested, OUAR was the most sensitive marker tested.
Chromosome analysis of preimplantation embryos after cadmium treatment of oocytes at meiosis I
Authors: Watanabe Toshiaki , Endo Akira 
Published: February 2007

AbstractFemale mice were given a single subcutaneous injection of cadmium chloride (1.5 mg or 3.0 mg/kg body weight) at the metaphase I stage of oogenesis. The incidences of blastocysts with trisomies and triploidies were significantly increased in the cadmium‐treated groups. Chromosome analysis of preimplantation embryos may be one of the useful in vivo methods for screening for chromosome anomalies induced in mammalian germ cells.
Sister chromatid exchanges in chines hamster cells treated with seventeen organophosphorus compounds in the presence of a metabolic activation system
Authors: Chen H. H. , Sirianni S. R. , Huang C. C. 
Published: February 2007

AbstractThe mutagenicity of several organophosphorus pesticides (OPP) has been demonstrated by Wild [1975] in microorganisms. However, the results as reported in the literature of cytogenic, mutagenic, and carcinogenic tests using mammalian cells or experimental animals were scanty and inconclusive [Huang, 1973; Wild, 1975]. This may be partly due to the high toxicity and rapid degradation of these compounds by mammalian cells both in vitro and in vivo [Wild, 1975]. Since sister chromatid exchange (SCE) has proved to be a highly sensitive indicator of genetic damage [Latt, 1975] and for certain chemicals there was a good correlation between the induction of SCE and point mutations in mammalian cells [Carrano et al, 1978; Sirianni and Huang, 1980], we have studied and reported the effect of a total of 17 OPP on induction of sister chromatid exchange and cell cycle delay in an in vitro system using V79 cells without metabolic activation [Chen et al, 1981, 1982]. Among the 17 OPP tested, 8 were able to induce increased SCE frequencies and the other 9 caused no increase in SCE as compared to the control values. The OPP that proved to be positive SCE inducers were methyl‐parathion, demeton, trichlorfon, dimethoate, malathion, methidathion, oxydemeton methyl, and fenthion. The other nine that caused no SCE increase were diazinion, disyston, amaze, azinphosmethyl, bolstar, DEF, fensulfothion, monitor, and nemacur. In addition, cell cycle delay in various degrees was observed after treatment of V79 cells with all the OPP except for fensulfothion and oxydemeton methyl. However, for all experiments there was no clear correlation between the degree of cell cycle delay and induction of SCE.
Effect of selection cell density on the recovery of mutagen‐induced 6‐thioguanine‐resistant cells (CHO/HGPRT system)
Authors: O'Neill J. P. , Bowman K. O. 
Published: February 2007

AbstractThe relationship between the cell density utilized in the selection for 6‐thioguaninine‐resistant mutants induced by ethyl methanesulfonate and the recovery of mutant colonies was determined in Chinese hamster ovary cells. After an adequate phenotypic expression time of 9 days post mutagen treatment, cultures were plated in selection medium at cell densities ranging from 5 × 104 to 2 × 106 cells/100 mm dish (0.9 to 36.0 × 103 cells/cm2). A decline in the frequency of mutant colonies was observed with increasing cell density, and analysis of the data showed that the loss was independent of the frequency of mutants in the cell population. This loss occurred in an exponential fashion, consistent with a random‐target effect. Regression analysis of the data points yielded a best‐fit line defined by the equation log(y) = 2.01 ‐ 0.26(10−6) x, where y = percentage recovery and × = selection cell density (cells per 100 mm dish). This study defines the cell densitydependent loss of mutants under selection conditions, and provides a basis for further study of the influence of agents on cell contact‐mediated crossfeeding and possible effects on mutation induction determinations. These results also demonstrate the importance of the use of appropriate cell densities in mutant selections.
Adult toxicity and dominant lethals induced by ozone at specific stages in spermatogenesis in drosophila virilis
Authors: Erdman H. E. , Hernandez T. 
Published: February 2007

AbstractOzone, a highly reactive three‐atom allotrope of oxygen, is formed in high concentrations in various kinds of microenvironments, including electron microscopes, office copy machines, and X‐ray devices. Mutagenicity and action modus operandi of ozone suggest its radiomimetic property. In order to test for ozone‐induced dominant lethals in Drosophila virilis, we determined that four‐hr and longer exposures to 30 ± 2 ppm ozone were lethal on or before day 25 postexpo‐sure. Accordingly, we used a three‐hr ozone exposure to investigate dominant lethals induced at specific spermatogenic stages. Ozone increased the percentage of dominant lethals in the stages of spermatogenesis which were investigated. Under the conditions of this experiment, the sperm‐sperm bundle stage showed the greatest percentage of dominant lethals induced by ozone. Meiotic cells were the least sensitive to ozone mutagenicity. The induction of dominant lethals is discussed on the basis of chemical reactions from the molecular decomposition of water by radiations and/or ozone. Alternative explanations are presented due to the definition of induced dominant lethals and to associated modifications from ozone exposure.
Detection of DNA damage in primary cultures of rat hepatocytes following in vivo and in vitro exposure to genotoxic agents
Authors: Bermudez E. , Mirsalis J. C. , Eales H. C. 
Published: February 2007

AbstractA simplified method for the quantitation of DNA damage in nonlabeled hepatocytes, using a fluorometric technique for the quantitation of DNA in conjunction with a modification of the alkaline elution technique of Kohn et al [1976], following chemical treatment in vitro and in vivo, is described. Freshly isolated hepatocytes were treated in vitro with 2‐acetylaminofluorene, aflatoxin B1, and dimethylnitrosamine, then examined for DNA damage. Exposure to each of these compounds resulted in DNA damage. Hepatocytes isolated from rats treated with the hepatocarcinogens 2‐acetylaminofluorene, benzidine, azoxymethane, dimethylhydrazine, dimethylnitrosamine, and diethylnitrosamine sustained DNA damage as evidenced by increased alkaline elution. DNA damage in hepatocytes was also observed as a result of treatment with methylmethanesulfonate and azaserine. The hepatotoxin carbon tetrachloride did not induce DNA damage in hepatocytes isolated from treated animals. A comparison of the induction of DNA damage and of unscheduled DNA synthesis in hepatocytes from the same animals revealed that in most cases the extent of elution of DNA from filters was proportional to the induction of DNA repair.
Mutagenicity test of extracts of airborne dust from the municipal incinerator of trieste
Authors: Pani B. , Laureni U. , Babudri N. , Collareta A. , Venturini S. , Ferri R. , Carrozzi M. , Burlini F. , Monti‐Bragadin C. 
Published: February 2007

AbstractThe composition of the effluents from incineration plants has been studied by several authors, and some chemical compounds have been identified as hazardous to the health of the people living in the environs of such plants. On the other hand, very little is known about the chemical risks for the people working inside the incineration plants. In the present paper, an evaluation of these risks has been attempted by testing for the mutagenic activity of the extracts of airborne particulates collected inside the working area of the Municipal Incinerator of Trieste. Most samples of dust were proved to be mutagenic by the Ames test, indicating that the environment is heavily polluted with incompletely burnt materials. In fact, when a sample of settled dust was heated at high temperatures, its mutagenic activity disappeared. In addition, samples of solid residues collected at the end of the combustion process showed only weak, if any, mutagenic response.
A comparative cytogenetic study on cases of induced abortions in tcdd‐exposed and nonexposed women
Authors: Tenchini M. L. , Crimaudo C. , Pacchetti G. , Mottura A. , Agosti S. , de Carli L. 
Published: February 2007

AbstractIn order to evaluate the cytogenetic findings previously obtained on induced abortions in women exposed to 2,3,7,8 tetrachlorodibenzo‐p‐Dioxim (TCDD) after the Seveso accident, chromosome analyses were carried out on a comparable control sample. The frequencies of aberrant cells, the relative proportions of individual types of chromosome aberration, the average number of lesions per damaged cell, and the frequencies of polyploids do not differ significantly in maternal blood and placenta in the two samples. A highly significant increase in the frequencies of aberrant cells and in the average number of aberrations per damaged cell was found in the fetal tissues in the group of exposed pregnancies. A noticeable feature of the data on the frequencies of cells with aberrations is the marked variability among individuals within tissues and within samples. On the basis of these results, the authors point to the need to continue cytogenetic investigations on interrupted pregnancies in TCDD‐exposed and nonexposed women.