bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of nitropyrene to the mutagenic activity of coal fly ash
Authors: Harris Wesley R. , Chess Edward K. , Okamoto Deborah , Remsen Joyce F. , Later Douglas W. 
Published: February 2007

AbstractStack‐collected coal fly ash from western low‐sulfur coal was extracted with 60:40 benzene/methanol. This extract was fractionated by preparative‐scale high performance liquid chromatography (HPLC) and the mutagenic activity of 14 fractions was evaluated by microbial assay with Salmonella typhimurium TA1538. A widespread distribution of direct‐acting mutagens, which probably includes both mono‐ and dinitroaromatics, was detected.HPLC methods were also used to isolate 1‐nitropyrene from the total benzene/methanol extract. The identification of 1‐nitropyrene was based on gas chromatographic and HPLC retention measurements and mass spectral data. The concentration of 1‐nitropyrene in the ash extract was determined by quantitative HPLC analyses. Mutagenicity assays of the total extract and an authentic 1‐nitropyrene standard with Salmonella strains TA1538, TA100, and TA98 indicated that the 1‐nitropyrene accounts for approximately 0.03‐0.16% of the total mutagenic activity of the extract.
Mutagenicity of some benzidine congeners and their N‐acetylated and N,N′‐diacetylated derivatives in different strains of Salmonella typhimurium
Authors: Reid Thomas M. , Wang Ching Y. , King Charles M. , Morton Kenneth C. 
Published: February 2007

AbstractThe Ames Salmonella/microsome test was used to compare the mutagenic response of Salmonella typhimurium TA100, TA98, TA1538, and TA1535 to 12 benzidine derivatives, ie, benzidine, 3,3′‐dimethoxybenzidine, 3,3′‐dimethylbenzidine, 3,3′‐dichlorobenzidine, and the corresponding N‐ and W,W‐diacetylated derivatives. With a few exceptions, the mutagenic response to this series of compounds varied in the order TA98 > TA1538 > TA100 > TA1535 = 0, and the N‐monoacetylated derivatives were more mutagenic than either the parent diamines or the N,N′‐diacetyl derivatives. The relative mutagenicities of the parent amines for TA98 were 3,3′‐dichlorobenzidine > > 3,3′‐dimethoxybenzidine > benzidine > 3,3′‐dimethylbenzidine.
Reduction of sister chromatid exchange frequency with time after mutagen exposure in chinese hamster ovary cells in the presence of 3‐aminobenzamide
Authors: Schwartz Jeffrey L. , Morgan William F. , Wolff Sheldon 
Published: February 2007

Abstract3‐Aminobenzamide (3AB) is a potent inhibitor of poly(ADP‐ribose) synthesis and has been reported to inhibit DNA repair. Inhibition of poly(ADP‐ribose) synthesis by 3AB results in a potentiation of the cytotoxic effects of alkylating agents and synergistically increases the frequency of sister chromatid exchanges (SCEs) induced in Chinese hamster ovary cells by methyl methanesulfonate (MMS). Experiments were carried out to determine if this synergism was related to an inhibition of the repair or the removal of SCE‐forming lesions by 3AB. Cells were treated with MMS or ethyl nitrosourea (ENU) and either held in a nonproliferative state or maintained in exponential growth for up to 48 hr before SCE frequencies were measured. During this time, the SCE frequency decreased greatly. 3AB did not affect this decrease in either cycling or noncycling cells. Furthermore, 3AB appears to exert its effect only in cycling cells when bromodeoxyuridine is present. Therefore, the synergism between 3AB and alkylating agents in the induction of SCEs is unrelated to effects of 3AB on the repair or removal of SCE‐forming lesions.
DNA‐damaging potential of diethylstilbestrol evaluated in the germ cell unscheduled dna synthesis assay
Authors: Racine R. R. , Schmid B. P. 
Published: February 2007

AbstractDespite the fact that the nonsteroidal estrogen diethylstilbestrol (DES) exerts its toxic effects primarily on the reproductive system, little is known about the possible interference of this compound with germ cell DNA. The measurement of unscheduled DNA synthesis (UDS) in spermatocytes and early spermatids of mice germ‐cells is a valid indicator for the DNA‐damaging potential of a compound. UDS occurrence was thus determined after IP administration of 10, 30, 60 or 180 mg/kg DES to male mice. Tritiated thymidine ([3H]dThd) was then injected into the testes, the spermatozoa were serially collected, the sperm heads isolated, and UDS determined by the amount of [3H]dThd incorporation.[3H]dThd measurements in germ cells of mice which were treated with 10 mg/kg DES were comparable to those of the controls. Higher incorporation of [3H]dThd, indicating UDS, was measured in sperm cells which had been spermatocytes at the time of treatment with 30 and 60 mg/kg DES; this increase was statistically significant at 60 mg/kg. Administration of 180 mg/kg DES caused [3H]dThd incorporation which was comparable to that of the controls, suggesting that DES interfered with repair mechanisms or delayed spermatogenic cycles at high dose levels. General toxicity was manifested in a dose‐dependent decrease of the sperm cell numbers in the spermatogenic stages investigated.This study provides evidence that DES, or its metabolite(s), reached the germ cells of adult mice in sufficient amounts to produce DNA damage. The levels of radioactivity measured were comparable to those measured after cyclophosphamide treatment, but [3H]dThd incorporation was about 10 times less than in methylmethane sulfonate‐treated animals.
Comparative studies of dose‐response curves for recessive lethal mutations induced by ethylnitrosourea in spermatogonia and in spermatozoa of Drosophila melanogaster
Authors: Yoshikawa Isao , Ayaki Toshikazu , Ohshima Kayoko 
Published: February 2007

AbstractInduction of recessive lethal mutations by N‐ethyl‐N‐nitrosourea (ENU) was studied for the second chromosome of spermatogonia and spermatozoa in Drosophila melanogaster. ENU (0.03,0.3, and 1.0 mM) was given to flies by dissolving it in feeding sucrose solution. Since flies are known to show increased avoidance of the feeding solution with increase in ENU concentration, the absorbed doses of ENU by flies were estimated from the previously determined empirical data for relation of ENU concentration in the feeding solution and the intake volumes of the solution by flies as measured indirectly via intake radioactivities of 3H‐labeled sucrose added to the solution. When plotted against absorbed doses of ENU, the observed frequencies of recessive lethals showed a linear relationship for induction in spermatozoa but a sigmoidal relationship for induction in spermatogonia. These results suggest that in spermatogonia ENU‐induced mutational damage is more repairable in a lower dose range of ENU. Mosaic lethal mutations were induced by ENU but not in spermatogonia.
Different effects of mutagens on sister chromatid exchange induction in three chinese hamster cell lines
Authors: Mehnert Karl , Vogel Walther , Benz Reiner , Speit Günter 
Published: February 2007

AbstractThe sister chromatid exchange (SCE) induction of mutagens with different mechanisms of action was comparatively investigated on permanent cell lines of the Chinese hamster (CHO, V‐79, and DON) with and without exogenous metabolic activation and with the use of various experimental protocols. CHO and V‐79 cells were treated with ethylmethanesulfonate (EMS), a direct mutagen; with the two indirect mutagens cyclophosphamide (CP) and benzo[a]pyrene (BP); as well as with the radical former hydrogen peroxide (H2O2) and hydroxyurea (HU), an inhibitor of DNA synthesis. Aside from an increased basal SCE level and a higher bromodeoxyuridine (Brdurd) sensitivity, there was no decisive difference betwen CHO and V‐79 cells. However, there was a distinct relationship between SCE induction and the experimental protocol used, which was most pronounced after HU treatment. Neither cell line was able to metabolize the indirect mutagen BP. Only in CHO cells did CP lead to increased SCE frequencies. However, in all cases, the simultaneous application of S9 mix produced a distinct SCE induction. In contrast, BP caused SCE induction in DON cells, whereas CP was not metabolized. The reason for these findings must obviously be sought in the metabolization of CP and BP via different monooxygenase systems, whose activity can differ in these permanent cell lines. One notable finding was that the number of SCE induced by H2O2 could be distinctly reduced by the simultaneous application of S9 mix. This effect can be explained by the fact that S9 mix contains H2O2‐degrading enzymes. The results indicate that closely related cell lines differ in their capability for inducing SCE and that investigations of SCE inductions performed on only one cell line do not necessarily produce a representative response.
Correlative genotoxicity studies of airborne particles in Salmonella typhimurium and cultured human lymphocytes
Authors: Krishna G. , Nath J. , Ong T. 
Published: February 2007

AbstractThe acetone extracts of ambient air particulates collected locally were tested for their capacity to induce sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) in human lymphocytes, and to induce gene mutations (GMs) in Salmonella typhimurium. The extracts caused dose‐related clastogenic/mutagenic responses in all three assay systems. With the same concentration, it seems that the Ames Salmonella/microsomal assay with TA98 gave the highest, and the chromosomal aberration assay with human lymphocytes the lowest, mutagenic/ clastogenic responses, respectively. Because high frequencies of SCEs were induced by solvent extracts of airborne particles, this study further indicated the usefulness of SCE assay in human lymphocytes for genotoxicity studies of airborne particles.
Spontaneous mutation frequencies in Salmonella: Enhancement of G/C to A/T transitions and depression of deletion and frameshift mutation frequencies afforded by anoxic incubation
Authors: Hartman Zlata , Hartman Philip E. , Barnes Wayne M. , Tuley Elodee 
Published: February 2007

AbstractIncubation of Salmonella typhimurium under anoxic conditions (0.1 % oxygen or less) results in a substantial decrease in small (3‐and 6‐basepair) deletions in an A/T‐rich region of the hisG gene in the hisG428 ochre mutant and also decreases the frequency of minus frameshift mutations in G/C‐rich sequences in the hisD3052 and hisC3076 mutants. In contrast, the frequency of G/C→ A/T transition mutations increases substantially during anoxic growth of hisG46. Growth of revertants of strains carrying accessory deletions in the uvrB region of the Salmonella chromosome is drastically impaired on glucose minimal medium when oxygen partial pressures are below 0.1% oxygen.
Mutagenic 1‐nitropyrene in wastewater from oil‐water separating tanks of gasoline stations and in used crankcase oil
Authors: Manabe Yoshiki , Kinouchi Takemi , Wakisaka Kazumi , Tahara Isao , Ohnishi Yoshinari 
Published: February 2007

AbstractWastewater collected from oil‐water separating tanks of ten gasoline stations for a year was fractionated into diethyl ether‐soluble neutral, acidic, and basic fractions. Mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98 and TA100 in the presence or absence of S9 mix. The neutral fractions showed high mutagenicity in the absence of S9 mix. Each neutral fraction was subjected to high‐performance liquid chromatography (HPLC) and fractionated. A 1‐nitropyrene(1‐NP)‐corresponding fraction was collected and analyzed by gas chromatography‐mass spectrometry (GC‐MS) and HPLC to prove that wastewater contains 1‐NP and to quantitate 1‐NP in wastewater. GC‐MS patterns showed the following molecular and fragment ion peaks of 1‐NP: 247, 217, 201, and 189. The amount of 1‐NP in 36 samples of wastewater was 4.2–25,600 ng per liter of wastewater, and 1‐NP accounted for O.3–58.5% of the total mutagenicity of the neutral fractions. The other 19 samples of wastewater did not contain any detectable 1‐NP. The mutagenicity of wastewater may be due to water from car washing and contamination by used crankcase oil.A Soxhlet extract of crankcase oil used in a gasoline engine was fractionated into three fractions as above. Mutagenicity was measured with strains TA98, TA100, TA98NR, and TA98/1,8‐DNP6 in the absence or presence of S9 mix. The neutral fraction showed the highest mutagenicity with strain TA98 in the absence of S9 mix, and its mutagenicity was decreased in strains TA98NR and TA98/1,8DNP6. The latter result indicates that the used engine‐oil contained 1‐NP and dinitropyrenes. Actually, the amounts of 1‐NP and 1,6‐diNP in used crankcase oil were 138 and 2.0 ng per ml of oil, respectively, and these concentrations accounted for 0.45 and 2.7%, respectively, of the total mutagenicity of the neutral fraction with strain TA98 in the absence of S9 mix. Moreover, the concentrations of 1‐NP and 1,6‐diNP in used crankcase oil of a diesel engine were 349 and 31 ng per ml of oil, respectively, accounting for 0.9 and 12%, respectively, of the total mutagenicity of the neutral fraction in the same assay system.
Suppressive effects of chemicals in mixture on the Salmonella plate test response in the absence of apparent toxicity
Authors: Zeiger Errol , Pagano Dennis A. 
Published: February 2007

AbstractThere are chemicals that affect the number of his + revertant colonies of Salmonella in the plate test at doses that are apparently nontoxic, but may be causing nonlethal, toxic effects. When mixed with mutagens, these chemicals reduce the numbers of his+ revertant colonies on the plate with no accompanying visible toxic effect on the background lawn. Some of these plates are indistinguishable from spontaneous control plates, leading to the possibility that the mutagens under test would be evaluated as nonmutagenic, or that the mutagenic response would be underestimated. The reduction in mutagen‐induced revertant colonies in most cases is equivalent to the reduction in spontaneous revertants in the absence of mutagen. A spot test that permits a rapid screen of chemicals for inhibitory effects has been developed; a plate incorporation assay is used to confirm the effect. Toxic effects can be seen in the background lawns of plates examined at magnifications of 100 X or greater.
Mutagenic activity of airborne particles inside and outside homes
Authors: Van Houdt J. J. , Jongen W. M. F. , Alink G. M. , Boleij J. S. M. 
Published: February 2007

AbstractIndoor concentrations of total suspended particles often exceed outdoor concentrations. Although it is known that particulate matter may contain mutagenic compounds and that several sources in the home produce mutagens, virtually no data concerning the mutagenicity of indoor particulate matter are available.In this study, experiments were carried out to determine the contribution of indoor and outdoor sources to the mutagenicity of indoor particles. Using six samplers, particles in kitchens, living rooms, and outdoors were collected simultaneously. Methanol extracts of the material obtained were tested in the Salmonella/microsome assay. An increase in mutagenic activity was shown in the presence of a metabolizing system in all indoor and outdoor samples but one. The data presented suggest that mutagenic components of indoor particulate matter are different from those found in outdoor particles. Indoor samples show a higher mutagenic activity after metabolic activation, while direct mutagenic activity of indoor particles was lower than that of outdoor particles. Furthermore, only indoor samples showed cytotoxic effects. Our findings suggest that, with respect to the mutagenic activity of particulate matter, cigarette smoke is the most important contaminant of indoor air. Kitchen samples also show mutagenic activity, probably as a result of volatilization of cooking products. No contribution of outdoor sources to mutagenicity of indoor particles was observed.
The use of carcinogen‐DNA adduct antisera for quantitation and localization of genomic damage in animal models and the human population
Authors: Poirier Miriam C. 
Published: February 2007

AbstractThe use of antibodies to detect chemical carcinogen‐induced DNA damage involves quantitative determination and morphological localization utilizing antisera specific for carcinogen‐DNA adducts. In recent years a large number of polyclonal and monoclonal antisera have been produced against individual adducts and modified DNAs with addition products varying in structure from ethyl and methyl groups to aromatic amines, polycyclic aromatic hydrocarbons, aflatoxins, and platinum‐ammine complexes. The quantitative assays developed through the use of these antisera are able to detect attomole (10−18 M) adduct concentrations, corresponding to one adduct in 108 nucleotides or a few hundreds of modifications per mammalian cell genome. This review focuses on data generated during the past 3 yr utilizing this immunotechnology as a tool to probe mechanisms of carcinogen‐DNA interactions in various model systems and in the human population. Areas discussed in depth include quantitative and morphological studies involving detection of 2‐acetylaminofluorene‐DNA adducts in rat liver, O6‐ethyl and O6‐methyl deoxyguanosine adducts in rat brain, benzo[a]pyrene‐DNA adducts in mouse skin and cis‐diamminedichloroplatinum (II)‐DNA adducts in peripheral nucleated blood cells of cancer patients.
Induction of forward mutation at the yg2 locus in maize by ethylnitrosourea
Authors: Schy William E. , Plewa Michael J. 
Published: February 2007

AbstractWe analyzed the kinetics of mutation induction at the yg2 locus in Zea mays by N‐ethyl‐N‐nitrosourea (ENU). ENU concentrations ranged from O.l to 10.7 mM and a linear, concentration‐dependent response was observed for the induction of yg2 sectors in leaf 4 and leaf 5. For both leaf 4 and leaf 5 ENU exhibited one‐hit kinetics consistent with either a point‐mutational or chromosome‐breakage mechanism of mutation induction. The mean induced mutation rate/mM ENU for the combined leaf 4 and leaf 5 data was 6.77 × 10−4 mutations/locus/mM ENU. This value was used to compare the mutagenic effectiveness of ENU with ethyl methanesulfonate (EMS) and to calculate a rad equivalent for ENU. ENU was found to be 3.8‐fold more effective than EMS. Based on their respective chemical reactivities with DNA, we propose that ENU predominantly induces point mutations at the yg2 locus. One rad of gamma radiation induced the same rate of mutation as an 8‐hr exposure to a 6.71 × 10−6 M concentration of ENU at 20°C.
Solvent interactions with test compounds and recommendations for testing to avoid artifacts
Authors: Nestmann Earle R. , Douglas George R. , Kowbel David J. , Harrington Tina R. 
Published: February 2007

AbstractReports in the literature describing artifactual results owing to interactions of test materials with solvents are becoming more frequent. The present study was initiated to examine possible interactions of 1,1,3‐trichloro‐, 1,1,3,3‐tetrachloro‐, pentachloro‐ and hexachloroacetones with different solvents, since certain solvent effects with the last compound have been shown previously. Quantitative differences in levels of mutagenic potency were found for tri‐, tetra‐, and pentachloroacetone, dissolved in acetone or dimethyl sulfoxide (DMSO). On the other hand, hexachloroacetone without solvent was mutagenic, and this activity was enhanced when it was dissolved in DMSO; in acetone it was not mutagenic. A time‐dependent reaction of hexachloroacetone with DMSO was the only test material‐solvent interaction found in this study. The results show clearly that DMSO is not an appropriate solvent for hexachloroacetone. On the basis of these and previous results, we recommend consideration of the following strategy to help prevent reporting of artifactual results owing to interaction with solvents: (1) Results from initial screening experiments should be confirmed in repeat experiments using a different solvent; and (2) a different solvent should be used in confirming the findings of other investigators. Differences in results would indicate a need for further study.
Mutagenesis assays of human amniotic fluid
Authors: Everson Richard B. , Milne Karen L. , Warburton Dorothy , McClamrock Howard D. , Buchanan Philip D. 
Published: February 2007

AbstractExtracts of amniocentesis samples from 144 women were tested for the presence of mutagenic substances using tester strain TA 1538 in the Ames Salmonella/ mammalian‐microsome mutagenicity test. Because the volume of amniotic fluid in these samples was limited (generally less than 10 ml), we investigated modifications of this mutagenesis assay that could increase its ability to detect effects from small quantities of test material. Using mutagenicity in samples of urine from smokers as a model, it appeared that improved ability to detect small amounts of mutagen could be obtained by reducing volumes of media and reagents while keeping the amount of test sample constant. This modification resulted in a test procedure capable of readily detecting mutagenicity in volumes of urine from smokers that were smaller than the volumes of amniotic fluid available. Tests of amniotic fluid extracts by this modified procedure showed small increases in revertants, about 50% above dimethylsulfoxide solvent control values. Results of procedures to control for technical factors possibly contributing to these increases suggested that the increased values could not be readily explained by contamination of test samples with mutagens during the extraction procedure. They also were not explained by alterations in spontaneous numbers of revertants associated with changes in the density of bacterial lawn growth. The increases suggest the presence of small amounts of mutagenic material in many of the amniotic fluid samples. At the doses employed, mutagenic activity in these samples was not associated with maternal smoking.
Niridazole: Evidence for promutagenic events involving guanine‐cytosine and adenine‐thymine base pairs
Authors: Speck William T. , Carr Howard S. , Rosenkranz Herbert S. 
Published: February 2007

AbstractNiridazole, a widely used antiprotozoan agent, is mutagenic for Salmonella typhimurium strains that contain guanine‐cytosine as well as adenine‐thymine base pairs at their mutational sites. The mutagenic activity for both types of targets depends upon nitroreduction.
A selective screen for transposable element mobilization in drosophila melanogaster
Authors: Clark S. H. , Chovnick A. 
Published: February 2007

AbstractA selective system is described that provides a simple and sensitive assay for the detection and analysis of induced mobile element transpositions in Drosophila melanogaster. The system will detect a single event in samples greater than 106 and thus provides a eucaryotic assay system for monitoring the induction of transposition by a variety of agents including, but not limited to, chemical carcinogens and toxins, ionizing radiation, and various environmental pollutants. The experimental system focuses on an X‐linked rosy+ transposon and a conditional lethal system that permits the detection of a single transposition event in very large samples. The results of a pilot experiment utilizing this system are presented.