bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐ray‐induced chromosome aberrations in down lymphocytes: An explanation of their increased sensitivity
Authors: Preston R. Julian 
Published: February 2007

AbstractUnstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X‐ray–induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosome aberrations, and hence higher aberration frequencies in Down than normal cells.
Increased cytotoxicity and mutagenicity of diesel fuel after reaction with NO2
Authors: Henderson Thomas R. , Li A. P. , Royer Robert E. , Clark Charles R. 
Published: February 2007

AbstractGas chromatography/mass spectrometry (GC/MS) of diesel fuel aromatics detected polynuclear aromatic hydrocarbons from naphthalenes to phenanthrenes, but no four‐ or five‐ring aromatics. This aromatic fraction treated with NO2 was found to contain nitro‐aromatics, but only the naphthalene and biphenyl nitro‐aromatics were detectable by direct GC/MS. By reduction of the nitro groups to amines, diazotization and reduction to yield aryl‐iodides, it was possible to demonstrate that nitro‐derivatives of most of the starting aromatics were present after NO2‐treatment. Diesel fuel was separated into aliphatic and aromatic fractions by extraction with dimethyl sulfoxide. These fractions were devoid of mutagenic activity in the Ames bioassay and exhibited low cytotoxicity to CHO cells in culture. However, after reaction with NO2, the products contained frameshift mutagens which did not require activation by S‐9 microsomal enzymes. The biological activity of the NO2‐treated aromatic fraction from fuel was more than 40 times greater in Salmonella TA100 than fuel aliphatics treated with NO2. The LC50 to CHO cells in culture increased more than fivefold for aromatics and more than tenfold for aliphatics. Similar to the diesel exhaust particulate extract, the cytotoxicity of the nitrated fractions was decreased by serum and glutathione. Reaction of fuel aromatics with NO2 may be one mechanism which contributes to the formation of cytotoxic and mutagenic activities in diesel exhaust.
Mutagenicity of coal fly ash: A new bioassay for mutagenic potential in a particle feeding ciliate
Authors: Smith‐Sonneborn J. , Palizzi R. A. , Herr C. , Fisher G. L. 
Published: February 2007

AbstractThe use of the established mutagenesis assay in Paramecium as a prescreen for hazardous environmental particles is described. Since these protozoans ingest particles of the size respired by animals and man, the biological effects of the respirable fraction of fly ash particles were monitored in particle‐feeding eukaryotic cells. Fly ash from coal combustion was utilized for these studies and was found to be mutagenic. The effects of physical and chemical treatment of the particle mutagenicity provided evidence for both heat‐stable, heat‐labile and acid extractable mutagenic agents.
The mutagenic and SOS‐inducing potential of the soluble organic fraction collected from diesel particulate emissions
Authors: Dukovich M. , Yasbin R. E. , Lestz S. S. , Risby T. H. , Zweidinger R. B. 
Published: February 2007

AbstractStudies involving the Ames Salmonella mutagenicity test and the Bacillus subtilis comptest have demonstrated that the soluble organic fraction of diesel particulate is potentially mutagenic and DNA damaging. The soluble organic fraction was extracted from exhaust particulate samples collected from four different diesel engines operated at specified conditions. For each fraction collected, an increase in the concentration of the organic material resulted in a subsequent increase in the number of histidine prototrophs obtained when this material was added to the histidine auxotrophic strains that comprise the Ames Salmonella test. Specifically, the number of induced revertants, for strains TA98 and TA100, ranged from less than one revertant per μg of sample to 29 revertants per μg of sample. The ability of these organic fractions to induce bacterial SOS functions also was determined by exposing competent cultures of Bacillus subtilis strain RUB827 to increasing concentrations of these extracts. With varying efficiencies, these samples were positive in their ability to induce the SOS system of B subtilis. Significantly, the toxicity of these mutagenic and DNA damaging samples never resulted in more than 95% killing, even for the highest concentrations tested in the Salmonella and B subtilis assay.
Mutagenicity of the mycotoxin botryodiplodin in the salmonella typhimurium/microsomal activation test
Authors: Moulé Yvonne , Decloitre Françoise , Hamon Gérard 
Published: February 2007

AbstractBotryodiplodin, a mycotoxin synthesized by some strains of Penicillium roqueforti was tested for lethal and mutagenic effects on Salmonella typhimurium (TA98). Botryodiplodin was active in the histidine reversion system without metabolic activation.
The use of adult rat liver cultures in the detection of the genotoxicity of various polycyclic aromatic hydrocarbons
Authors: Tong C. , Laspia M. F. , Telang S. , Williams G. M. 
Published: February 2007

AbstractThe hepatocyte primary culture (HPC)‐DNA repair test and the adult rat liver epithelial cell (ARL)—hypoxanthine‐guanine phosphoribosyl transferase (HGPRT) mutagenesis assay are two in vitro short‐term tests that possess intrinsic capability for xenobiotic biotransformation. Both assays detected the genotoxicity of a variety of carcinogenic polycyclic aromatic hydrocarbons. Thus, these two tests, which embody intact cellular metabolism, are useful for the evaluation of this class of carcinogens and provide results that strengthen those obtained in tests dependent upon subcellular metabolism.
The mutagenic effect of cis‐diamminedichloroplatinum (II) and its degradation products in the ames microbial assay
Authors: Peer Richard L. , Litz Deborah A. 
Published: February 2007

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 mutations.
Sister chromatid exchange induction and cell cycle inhibition by aniline and its metabolites in human fibroblasts
Authors: Wilmer James L. , Kligerman Andrew D. , Erexson Gregory L. 
Published: February 2007

AbstractSister chromatid exchange (SCE) and cell cycle analyses in human fibroblasts were used to ascertain the relative genotoxicity and cytotoxicity of aniline and its metabolites. Fibroblasts were allowed to attach to plastic petri dishes for 4 hr and exposed in serum‐free medium for 2 hr to the following: aniline HCl (0.05–10.0 mM), acetanilide (0.1–10.0 mM), o‐hydroxyacetanilide (0.01–2.0 mM), p‐hydroxyacetanilide (0.1–10.0 mM), o‐aminophenol (0.01–0.3 mM), p‐aminophenol (0.005–0.2 mM), N‐phenylhydroxylamine (0.001–0.5 mM). Triethylenemelamine (TEM; 0.25 and 0.49 μM) was used as a positive control. The treatment medium was replaced with complete medium containing 5‐bromo‐deoxyuridine (10 μM), and cells were allowed to grow for 48 hr with Colcemid present for the final 4.5 hr. Cell cycle analyses (percentage of cells in first, second, or third division) revealed that p‐hydroxyacetanilide (10mM), p‐aminophenol (≥0.1 mM), o‐aminophenol (≥0.1 mM), N‐phenylhydroxylamine (≥ mM), and TEM (0.49 μM) inhibited cell proliferation. Cell death was seen at doses of 0.5 mM N‐phenylhydroxylamine, 0.2 mM p‐aminophenol, and 0.3 mM o‐aminophenol. Significant increases (P0.05) in SCE frequencies were found with aniline HCl, o‐aminophenol, N‐phenylhydroxylamine, and TEM. On an SCE/mmole basis at the highest concentrations examined, o‐aminophenol was 270 times more potent than aniline in inducing SCE, whereas TEM was about 390 times more potent than o‐aminophenol. Furthermore, fibroblasts treated with o‐aminophenol responded in a dose‐dependent fashion and exhibited a 2‐fold increase in SCE frequency. N‐phenylhydroxylamine induced a less clear‐cut, dose‐related increase in SCE frequency with a 1.4‐fold elevation. Only marginal increases in SCE were observed with aniline at the highest doses. Using these data, we propose that aniline may exert its tumorigenic potential in rats through the production of both genotoxic and cytotoxic metabolites.
Cytogenetic effects of two antimonial antibilharzial drugs: Tartar emetic and bilharcid
Authors: Nahas Soheir El , Temtamy Samia A. , De Hondt H. A. 
Published: February 2007

AbstractThe effects of tartar emetic and bilharcid, two antimonial antibilharzial drugs, on the chromosomes of laboratory rats are studied. The drugs were administered intraperitoneally in three doses—clinical, intermediate, and maximum tolerated — both acutely (6, 24, and 48 hours) and subacutely. The two drugs produced the same types of chromosomal aberrations with tartar emetic, inducing a higher rate of incidence. No significant differences in the number of cells with chromosomal aberrations were generally observed among the 6, 24, and 48 hours of the acute treatment with both tartar emetic and bilharcid. The dose‐response relationship was examined for both the acute and the subacute treatments. Whereas the acute treatment of tartar emetic showed a dose‐dependent linear increase in the number of cells with chromosomal aberrations, the subacute treatment of tartar emetic and the acute and subacute treatments of bilharcid displayed their maximum effects at an intermediate dose.
Characterization of sister chromatid exchange induction by hydrogen peroxide
Authors: Speit G. , Vogel W. , Wolf M. 
Published: February 2007

AbstractHydrogen peroxide (H2O2) induces SCEs in V‐79 Chinese hamster cells. The incorporation of BrdUrd sensitizes the cells to the action of H2O2, but damage leading to the formation of SCEs can also be induced in DNA not substitued with BrdUrd. Catalase leads to a complete reduction of the SCE‐producing as well as the toxic effect. The amino acid L‐cysteine does not reduce the H2O2‐induced SCE‐frequencies. The results yield information about the relevance of SCE investigations in vitro for the determination of DNA‐damaging substances and about the effects of antimutagenic SH‐compounds.
Variations among species and cell types in the effects of caffeine on mutagen‐induced cytotoxicity and postreplication repair of DNA
Authors: Sivak Andrew , Rudenko Larisa , Teague Linda Gaudio 
Published: February 2007

AbstractThe influence of caffeine on cytotoxicity and postreplication repair of DNA was examined following exposure of several cell types to physical and chemical agents known to damage DNA. The cell types used in this study were normal human fibroblasts (HS‐WP), human xeroderma pigmentosum fibroblasts (SGL), Chinese hamster V79 cells, mouse BALB/c‐3T3 cells, and secondary Syrian hamster embryo cells. The DNA damaging agents were ultraviolet light (UV), N‐2‐acetoxyfluorenylacetamide (AFAA), nitroquinoline‐N‐oxide (NQO) and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG). Induction of cytotoxicity in Chinese hamster V79 cells due to ultraviolet light or AFAA exposure was enhanced by caffeine at a concentration of 1.0 mM in the culture medium, but not at 0.2 or 0.05 mM. Caffeine also inhibited postreplication repair in these cells at the same concentrations. In contrast, postreplication repair was not affected by caffeine at concentrations up to 1.0 mM in normal human fibroblasts (HS‐WP), human xeroderma pigmentosum fibroblasts (SGL), secondary Syrian hamster embryo cells, and mouse BALB/c‐3T3 cells following treatment with ultraviolet light, AFAA, NQO, or MNNG. Cytotoxicity in BALB/c‐3T3 cells following exposure to ultraviolet light or AFAA was enhanced in the presence of caffeine at 1.0 or 0.2 mM, although these concentrations of caffeine had no effect on postreplication repair in these cells. The inhibitory effect of caffeine on postreplication repair was found only in Chinese hamster V79 cells among the five cell types used in this study. Both normal and xeroderma pigmentosum human cells repaired mutagen‐induced DNA damage equally well in the absence or presence of caffeine at concentrations of 1.0 mM or less.
Ph stability of some mutagens produced by aqueous chlorination of organic compounds
Authors: Nazar Mark A. , Rapson W. Howard 
Published: February 2007

AbstractAqueous chlorination of many organic substances has been found to produce substantial mutagenicity in Salmonella typhimurium TA100. An effective way to decrease such mutagenicity is to raise the pH of the solutions to neutrality or higher. The effect of pH on the mutagenicity of the filtrate from the chlorination of unbleached kraft wood pulp and of certain mutagens found in such filtrates has been investigated. The decay of mutagenicity of the known mutagens has been shown to proceed by cleavage of organically bound chlorine by hydroxide ion. Caution is recommended with respect to the practice of raising the pH of solutions for mutagenesis assays.
Mutagenicity screening of foods I. Results with beverages
Authors: Stoltz D. R. , Stavric B. , Krewski D. , Klassen R. , Bendall R. , Junkins B. 
Published: February 2007

AbstractFollowing a number of recent reports on the presence of mutagens in certain foods, a general survey of the mutagenic potential of a wide variety of food products has been initiated. Here, results for samples of 28 widely consumed beverages from 13 general categories are reported. Each sample was concentrated and fractionated by polarity and solubility to give up to seven fractions, each of which was assayed for mutagenic potential with Salmonella typhimurium TA98 and TA100 ± fortified liver homogenate. Fractions showing evidence of either mutagenicity or toxicity were retested at the same and lower concentrations. The utility of the fractionation procedure and the sensitivity of the screening strategy were established by assaying six beverages spiked with known mutagens prior to fractionation. Statistical analysis of the data resulted in positive findings for seven beverages, although confirmation of these results through analysis of a second sample was obtained only for red wine, grape juice, and instant coffee. The remaining 21 beverages showed no strong evidence of mutagenic activity. For those foods for which the variation among replicate plates was largest, the false‐positive rate for the two‐stage screening procedure employed was estimated to be less than 1% while the false‐negative rate for a beverage inducing a threefold increase in the background mutation rate was conservatively estimated to be limited to 14%.
The longevity of chemically induced sister chromatid exchanges in chinese hamster ovary cells
Authors: Muscarella Donna E. , Bloom Stephen E. 
Published: February 2007

AbstractThe persistence of the lesions leading to sister chromatid exchanges (SCEs) following acute exposure of Chinese hamster ovary (CHO) cells to direct‐acting chemical mutagens was measured. The results revealed that these lesions (and consequently SCEs) are rapidly eliminated from cells. SCE levels fell to near control values by the third or fourth day (six and eight cell cycles, respectively) following exposure of CHO cells to quinacrine mustard (QM) and mitomycin C (MMC). In contrast, cells exposed to methyl methanesulfonate (MMS) showed a small but significant increase in SCE level over control up to and including the fifth day following exposure (approximately ten cell cycles), suggesting that the behavior of these lesions in cells is influenced, at least in part, by the mechanism by which a specific agent interacts with DNA. The possibility that the decline in SCE level was due to the loss of cell populations with high numbers of exchanges was eliminated by the assessment of cloning efficiencies of treated and control cultures.
The solvent dimethylsulfoxide (DMSO) does not induce aneuploidy in oocytes of drosophila melanogaster
Authors: Traut H. 
Published: February 2007

AbstractBoth with a conventional method and with the “aneuploidy pattern method” we tested whether the solvent dimethylsulfoxide (DMSO) is able to induce aneuploidy (numerical chromosome aberrations) in oocytes of Drosophila melanogaster. DMSO was fed as a 2% solution to Drosophila females. No evidence for a mutagenic activity was obtained. This finding and the negative results reported by other authors for other types of mutation in Drosophila show that DMSO can be used as a solvent for chemical agents in mutagenicity screening in Drosophila melanogaster.
Chromosome damage and SCE induced by the cytostatic factor homo‐aza‐steroidal ester of P‐bis (2‐chloro‐ethyl) amino phenyl acetic acid in CHO cells in culture
Authors: Athanasiou Kyriacos , Demopoulos Nicos A. , Catsoulacos Panayiotis 
Published: February 2007

AbstractThe cytogenetic effects of homo‐aza‐steroidal ester (ASE) on Chinese hamster ovary (CHO) cells in vitro are reported. It was found that treatment of cells with a dose as low as 0.025 μg/ml of ASE causes a significant number of abnormal metaphases containing mostly chromatid‐type aberrations. Similarly, significant frequencies of SCE were induced with only 0.075 μg/ml of ASE.
Review: Putative mutagens and carcinogens in foods. IV. Malonaldehyde (malondialdehyde)
Authors: Hartman Philip E. 
Published: February 2007

AbstractMalonaldehyde or malondialdehyde (MA) is an ubiquitous dietary constituent formed by the peroxidation of unsaturated fatty acids and of the food additive, sorbate. The average US citizen consumes between 0.2 and 0.6 μg of MA each day from fresh and processed meats alone. This figure might have been considerably higher in past decades when meat was packaged and stored under less optimal circumstances. No studies seem to have been performed to determine if free MA is released under physiological conditions, such as in simulated gastric juice. Although pure enzymologically synthesized MA is a weak mutagen for a new Salmonella frameshift tester strain containing a polyadenine sequence, reports of more pronounced mutagenicity and carcinogenicity are very likely erroneous. The impure chemically synthesized MA samples used in the strongly positive tests for genotoxic activity were contaminated with mutagenic methoxy‐and ethoxyacroleins that would not be expected to constitute important components of foodstuffs. Thus, the greatest importance of MA and other carbonyls in foodstuffs may be their ability to catalyze nitrosation reactions in the presence of free nitrite and as indicators of the presence of other lipid oxidation products.
Mutagenicity testing of two tropical plant materials with pesticidal potential in salmonella typhimurium: Phytolacca dodecandra berries and oil from seeds of azadirachta indica
Authors: Jongen W. M. F. , Koeman J. H. 
Published: February 2007

AbstractIn this study the mutagenic potential of two tropical plant materials was investigated in Salmonella typhimurium strains TA98 and TA 100. The oil extract from seeds of Azadirachta indica showed no mutagenic activity in either strain with or without addition of metabolizing systems.When extracts of Phytolacca dodecandra berries were tested, only the butanol extract caused direct mutagenicity in TA98. After addition of rat liver homogenate, again only the butanol extract was positive in TA98. Addition of gut flora extract as metabolizing system generated positive effects in both the methanol extract and the butanol extract. The water extract showed only a slight positive effect, which can most probably be ascribed to the presence of histidine in the sample.
Statistical analysis and sample‐size determinations for mutagenicity experiments with binomial responses
Authors: Margolin Barry H. , Collings Bruce J. , Mason James M. 
Published: February 2007

AbstractTwo statistical analyses are studied for their applicability to mutagenicity experiments that produce binomial responses from a control group and a single treated group. Attention is focused on experiments with (1) group sample sizes greater than 500 and (2) a probability less than .05 for a binary observation from any experimental unit being “positive.” In addition, it is assumed that historical control data will not be included in the statistical analysis. The first analysis is a conditional binomial test, which has been tabulated extensively by Kastenbaum and Bowman [1970], while the second is based on a standard normal approximation to the distribution of the difference between two sample proportions. A formula is presented for each analysis that relates the associated probability of detecting a mutagen to the mutant frequencies and sample sizes of the two groups. Based on extensive numerical results, the conclusion is drawn that the normal test is the preferred analysis for experiments in which the ratio of the two sample sizes is between 0.80 and 1.25. On the further assumption that an experiment is to be conducted with equal experimental group sample sizes, recommendations are offered for values of this common sample size needed to achieve a specified power, ie, a degree of assurance of detecting a postulated level of mutagenic effect.
Optimal phenotypic expression times for HPRT mutants induced in foreskin‐, skin‐, and lung‐derived human diploid fibroblasts
Authors: Jacobs Lois , Bean Christian L. , Marx James A. 
Published: February 2007

AbstractA series of paired lung‐ and skin‐derived fibroblast cultures has been established from human embryonic tissues under carefully controlled, identical conditions, providing the unique opportunity to study differences between normal diploid fibroblast populations from skin and lung without the confusion of genetic differences between donors. To reliably assess differences in the induced mutation frequencies observed among different cell populations, optimal phenotypic expression times in the HPRT mutagenesis system were determined for neonatal foreskin, fetal skin, and fetal lung cultures. Cell populations were mutagenized with several doses of N‐methyl‐N'‐nitro‐N‐nitrosoguanidine and were replated in 6‐thioguanine selective medium at intervals over 14 days. Survivals following MNNG exposure ranged from 1.6% to 45.5%. For all doses and survivals tested a 7‐day expression period was the optimal value for cultures from the three different tissue sources in six independent experiments. Mutant frequency data derived from untreated control populations confirmed that spontaneous mutations during the expression period contributed negligibly to the final mutant frequency. Differences between the mutation frequencies obtained using an in situ and a replating protocol were approximately twofold for lung‐, skin‐, and foreskin‐derived cultures.