Mutagenic activities of biochars from pyrolysis.

Science.gov (United States)

Piterina, Anna V; Chipman, J Kevin; Pembroke, J Tony; Hayes, Michael H B

2017-08-15

Biochar production, from pyrolysis of lignocellulosic feedstocks, agricultural residues, and animal and poultry manures are emerging globally as novel industrial and commercial products. It is important to develop and to validate a series of suitable protocols for the ecological monitoring of the qualities and properties of biochars. The highly sensitive Salmonella mutagenicity assays (the Ames test) are used widely by the toxicology community and, via the rat liver extract (S9), can reflect the potential for mammalian metabolic activation. We examined the Ames test for analyses of the mutagenic activities of dimethylsulphoxide (DMSO) extracts of biochars using two bacterial models (S. typhimurium strains TA98 and TA100) in the presence and in the absence of the metabolic activation with the S9-mix. Tester strain TA98 was most sensitive in detecting mutagenic biochar products, and the contribution of S9 was established. Temperature and times of pyrolysis are important. Biochar pyrolysed at 400°C for 10min, from a lignocellulose precursor was mutagenic, but not when formed at 800°C for 60min, or at 600°C for 30min. Biochars from poultry litter, and manures of calves fed on grass had low mutagenicities. Biochar from pig manure had high mutagenicity; biochars from manures of cows fed on a grass plus cereals, those of calves fed on mother's milk, and biochars from solid industrial waste had intermediate mutagenicities. The methods outlined can indicate the need for further studies for screening and detection of the mutagenic residuals in a variety of biochar products. Copyright © 2017. Published by Elsevier B.V.

Impact of environmental exposures on the mutagenicity/carcinogenicity of heterocyclic amines

Energy Technology Data Exchange (ETDEWEB)

Felton, James S; Knize, Mark G; Bennett, L Michelle; Malfatti, Michael A; Colvin, Michael E; Kulp, Kristen S

2004-05-20

Carcinogenic heterocyclic amines are produced from overcooked foods and are highly mutagenic in most short-term test systems. One of the most abundant of these amines, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), induces breast, colon and prostate tumors in rats. Human dietary epidemiology studies suggest a strong correlation between either meat consumption or well-done muscle meat consumption and cancers of the colon, breast, stomach, lung and esophagus. For over 20 years our laboratory has helped define the human exposure to these dietary carcinogens. In this report we describe how various environmental exposures may modulate the risk from exposure to heterocyclic amines, especially PhIP. To assess the impact of foods on PhIP metabolism in humans, we developed an LC/MS/MS method to analyze the four major PhIP urinary metabolites following the consumption of a single portion of grilled chicken. Adding broccoli to the volunteers' diet altered the kinetics of PhIP metabolism. At the cellular level we have found that PhIP itself stimulates a significant estrogenic response in MCF-7 cells, but even more interestingly, co-incubation of the cells with herbal teas appear to enhance the response. Numerous environmental chemicals found in food or the atmosphere can impact the exposure, metabolism, and cell proliferation response of heterocyclic amines.

Impact of environmental exposures on the mutagenicity/carcinogenicity of heterocyclic amines

International Nuclear Information System (INIS)

Felton, James S.; Knize, Mark G.; Bennett, L. Michelle; Malfatti, Michael A.; Colvin, Michael E.; Kulp, Kristen S.

2004-01-01

Carcinogenic heterocyclic amines are produced from overcooked foods and are highly mutagenic in most short-term test systems. One of the most abundant of these amines, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), induces breast, colon and prostate tumors in rats. Human dietary epidemiology studies suggest a strong correlation between either meat consumption or well-done muscle meat consumption and cancers of the colon, breast, stomach, lung and esophagus. For over 20 years our laboratory has helped define the human exposure to these dietary carcinogens. In this report we describe how various environmental exposures may modulate the risk from exposure to heterocyclic amines, especially PhIP. To assess the impact of foods on PhIP metabolism in humans, we developed an LC/MS/MS method to analyze the four major PhIP urinary metabolites following the consumption of a single portion of grilled chicken. Adding broccoli to the volunteers' diet altered the kinetics of PhIP metabolism. At the cellular level we have found that PhIP itself stimulates a significant estrogenic response in MCF-7 cells, but even more interestingly, co-incubation of the cells with herbal teas appear to enhance the response. Numerous environmental chemicals found in food or the atmosphere can impact the exposure, metabolism, and cell proliferation response of heterocyclic amines

Urinary 1-hydroxypyrene and mutagenicity in bus drivers and mail carriers exposed to urban air pollution in Denmark.

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Hansen, Ase Marie; Wallin, Håkan; Binderup, Mona Lise; Dybdahl, Marianne; Autrup, Herman; Loft, Steffen; Knudsen, Lisbeth Ehlert

2004-01-10

Previous studies in Denmark have shown that bus drivers and tramway employees were at an increased risk for developing several types of cancer and that bus drives from central Copenhagen have high levels of biomarkers of DNA damage. The present study evaluates 1-hydroxypyrene concentrations and mutagenic activity in urine as biomarkers of exposure in non-smoking bus drivers in city and rural areas on a work day and a day off and in non-smoking mail carriers working outdoors (in the streets) and indoors (in the office). Twenty-four hour urine samples were collected on a working day and a day off from 60 non-smoking bus drivers in city and rural areas and from 88 non-smoking mail carriers working outdoors (in the streets) and indoors (in the office). The concentration of 1-hydroxypyrene was measured by means of HPLC and the mutagenic activity was assessed by the Ames assay with Salmonella tester strain YG1021 and S9 mix. The N-acetyltransferase (NAT2) phenotype was used as a biomarker for susceptibility to mutagenic/carcinogenic compounds. Bus drivers excreted more 1-hydroxypyrene in urine than did mail carriers. The differences were slightly smaller when NAT2 phenotype, cooking at home, exposure to vehicle exhaust, and performing physical exercise after work were included. The NAT2 slow acetylators had 29% (1.29 [CI: 1.15-1.98]) higher 1-hydroxypyrene concentrations in urine than the fast acetylators. Male bus drivers had 0.92 revertants/mol creatinine [CI: 0.37-1.47] and female bus drivers 1.90 revertants/mol creatinine [CI: 1.01-2.79] higher mutagenic activity in urine than mail carriers. The present study indicates that bus drivers are more exposed to polycyclic aromatic hydrocarbons (PAH) and mutagens than mail carriers. Mail carriers who worked outdoors had higher urinary concentration of 1-hydroxypyrene, a marker of exposure to PAH, than those working indoors. The individual levels of urinary mutagenic activity were not correlated to excretion of 1

Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay

Science.gov (United States)

Liu, Li; Chen, Ling; Floehr, Tilman; Xiao, Hongxia; Bluhm, Kerstin; Hollert, Henner; Wu, Lingling

2015-01-01

Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (−) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components. PMID:26606056

Analysis of commercial bouillons for trace levels of mutagens.

Science.gov (United States)

Stavric, B; Matula, T I; Klassen, R; Downie, R H

1993-12-01

A new method, developed specifically for the extraction of heterocyclic aromatic amine (HAA) type mutagens from different food matrices, was applied to various forms of commercially available bouillons. This procedure is based on liquid-liquid extraction of the sample at different pH values. Recovery and reproducibility of the procedure was determined by processing spiked samples using a mutagenicity bioassay technique as an endpoint. The mutagenicity was tested in the Salmonella/microsome assay using strain TA98 with metabolic activation. 22 bouillon samples in liquid, cube or powder forms from seven manufacturers were extracted and tested for potential mutagenicity. The mutagenic activity of these samples varied and ranged from non-detectable to about 1200 induced revertants per gram of solid material, with a median value of approximately 250 revertants/g. The mutagenic response appeared to be dependent on the source rather than the type or form of the product tested. A negative response was obtained from only one chicken bouillon, and the highest positive response was obtained from a beef bouillon in cube form. It appears that the average beef sample, regardless of form, has a higher mutagenic potency than chicken or chicken and turkey samples. Overall, the intake of mutagens from commercial bouillons (obtained as cubes, concentrates or dry mixes) to prepare one serving (as bouillon, soup, casseroles, etc.) is considerably less than that reported in the literature for one serving of fried beef or pork. The extractability and mutagenic characteristics of these samples indicate the presence of HAA-type mutagens. Work is in progress to identify the mutagenic factors in bouillons.

Exposure to polycyclic aromatic hydrocarbons (PAHs), mutagenic aldehydes and particulate matter during pan frying of beefsteak.

Science.gov (United States)

Sjaastad, Ann Kristin; Jørgensen, Rikke Bramming; Svendsen, Kristin

2010-04-01

Cooking with gas or electric stoves produces fumes, especially during frying, that contain a range of harmful and potentially mutagenic compounds as well as high levels of fine and ultrafine particles. The aim of this study was to see if polycyclic aromatic hydrocarbons (PAHs) and higher mutagenic aldehydes which were collected in the breathing zone of the cook, could be detected in fumes from the frying of beefsteak. The frying was performed in a model kitchen in conditions similar to those in a Western European restaurant kitchen. The levels of PAHs (16 EPA standard) and higher aldehydes (trans,trans-2,4-decadienal, 2,4-decadienal, trans-trans-2,4-nonadienal, trans-2-decenal, cis-2-decenal, trans-2-undecenal, 2-undecenal) were measured during frying on an electric or gas stove with margarine or soya bean oil as the frying fat. The number concentration of particles electric stove causes increased occupational exposure to some of the components in cooking fumes which may cause adverse health effects.

Mutagenic potential scale developed for relative evaluation of biological system response to environments presenting different gamma exposure rates

International Nuclear Information System (INIS)

Nouailhetas, Yannick; Almeida, Carlos E. Bonacossa de; Mezrahi, Arnaldo; Shu, Jane; Xavier, Ana Maria

1999-01-01

The elaboration of a mutagenic potential scale (MPS) will be accomplished through the evaluation of the frequency of induced mutations in a plant biological system in different sites. The selection of these sites will be based on general public perception of risk to health. In this selection, it will include areas such ecological paradises and also neighborhoods of nuclear reactors and uranium mining and milling industry with potential radiological impact. The developed project foresees the contribution of other research groups that will also provide data from different sites. The referred scale will be built based on the response of the genetic system that gives color to the cells of Tradescantia (BNL 4430) stamen hair to mutagenic agents. Methodological improvements has been developed aiming the computerization of mutagenic events evaluation and statistical analysis of data that will significantly increase the efficiency of the system and obtention of results. Other biological systems of environmental quality are being added to the project, for future use. MPS should facilitate the general public and professionals of the nuclear area to understand risks, on a biological basis, of exposure from radiologically impacted environments. (author)

Mutagenicity of urine from nurses handling cytostatic drugs, influence of smoking

Energy Technology Data Exchange (ETDEWEB)

Bos, R P; Leenaars, A O; Theuws, J L; Henderson, P T

1982-01-01

Mutagenicity towards Salmonella typhimurium TA 100 of urine from smoking nurses, who were occupationally involved in the treatment of patients with cytostatic drugs, was significantly increased in comparison with that of smoking control subjects. Mutagenicity towards Salmonella typhimurium TA 100 was not increased in exposed non-smokers when compared to control non-smokers. In smoking subjects urinary mutagenicity appeared increased towards Salmonella typhimurium TA 1538 in the presence of S-9 mix. Rats pretreated with Aroclor 1254 showed higher mutagenicity in their urine than untreated rats after cyclophosphamide administration. Therefore, the synergistic effect of smoking might be due in part to induction of enzymes involved in the mutagenic activation of cytostatic drugs. Further, the animal experiments showed that cyclophosphamide (the most frequently used mutagenic cytostatic drug) can be absorbed after oral or percutaneous administration. Therefore, it is not excluded that differences in working hygiene between smokers and non-smokers also play a role.

Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

Science.gov (United States)

Riedel, Theran P.; DeMarini, David M.; Zavala, Jose; Warren, Sarah H.; Corse, Eric W.; Offenberg, John H.; Kleindienst, Tadeusz E.; Lewandowski, Michael

2018-04-01

Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state atmospheric simulation chamber by irradiating mixtures of single aromatic VOCs, NOx, and ammonium sulfate seed aerosol in air. The 10 VOCs examined were benzene; toluene; ethylbenzene; o-, m-, and p-xylene; 1,2,4- and 1,3,5-trimethylbenzene; m-cresol; and naphthalene. Salmonella were exposed at the air-agar interface to the generated atmospheres for 1, 2, 4, 8, or 16 h. Dark-control exposures produced non-mutagenic atmospheres, illustrating that the gas-phase precursor VOCs were not mutagenic at the concentrations tested. Under irradiation, all but m-cresol and naphthalene produced mutagenic atmospheres, with potencies ranging from 2.0 (p-xylene) to 11.4 (ethylbenzene) revertants m3 mgC-1 h-1. The mutagenicity was due exclusively to direct-acting late-generation products of the photooxidation reactions. Gas-phase chemical analysis showed that a number of oxidized organic chemical species enhanced during the irradiated exposure experiments correlated (r ≥ 0.81) with the mutagenic potencies of the atmospheres. Molecular formulas assigned to these species indicated that they likely contained peroxy acid, aldehyde, alcohol, and other functionalities.

Varied exposure to carcinogenic, mutagenic, and reprotoxic (CMR) chemicals in occupational settings in France

Energy Technology Data Exchange (ETDEWEB)

Havet, Nathalie [Univ. Claude Bernard Lyon 1 (France). Lab. SAF; Penot, Alexis [Lyon Univ. (France). ENS Lyon, GATE-UMR 5824-CNRS; Morelle, Magali; Perrier, Lionel [Lyon Univ. (France). Direction de la Recherche Clinique et de l' Innovation; Charbotel, Barbara [Univ. Claude Bernard Lyon 1 (France). Centre Hospitalier Lyon Sud Service des Maladies Professionnelles; Fervers, Beatrice [Lyon Univ. (France). Dept. Cancer and Environment

2017-02-15

To explore varied exposure to carcinogenic, mutagenic, and reprotoxic chemicals (CMR) for French employees. Our study assessed data from the French national cross-sectional survey of occupational risks (SUMER) that was conducted in 2010 in a national representative sample of employees. We selected 28 CMR agents that were classified by the International Agency for Research on Cancer or European Union as being known or presumed to have CMR potential in humans. The association of individual and job characteristics with exposure prevalence, duration, and intensity of the CMR agents during a 1-week period was examined using multilevel logistic regression analysis. Overall, 10.4% of employees in 2010 were exposed to one or more CMR agents at their workplace, and 3.4% were subjected to multiple CMR exposures. Blue-collar workers, night-shift workers and workers with short-term employment contracts experienced higher exposure prevalence (p < 0.01) and intensity (p < 0.05). Bluecollar workers and shift workers experienced also longer exposure duration (p < 0.001). Conversely, managers, workers of large companies, and women were less exposed to CMR agents (p < 0.001). The presence of a Committee for Health, Safety, and Working Conditions, and intervention by Occupational Health and Safety officers were significantly associated with reduced exposure intensities (p < 0.001 and p < 0.05). Establishment of European CMR regulations and the existence of an applicable substitution principle reduced the exposure duration (p < 0.001) and intensity (p < 0.05). Our results point out disparities in CMR exposure and identify high-priority targets for prevention measures to help reducing social health discrepancies.

Varied exposure to carcinogenic, mutagenic, and reprotoxic (CMR) chemicals in occupational settings in France

International Nuclear Information System (INIS)

Havet, Nathalie; Penot, Alexis; Morelle, Magali; Perrier, Lionel; Charbotel, Barbara; Fervers, Beatrice

2017-01-01

To explore varied exposure to carcinogenic, mutagenic, and reprotoxic chemicals (CMR) for French employees. Our study assessed data from the French national cross-sectional survey of occupational risks (SUMER) that was conducted in 2010 in a national representative sample of employees. We selected 28 CMR agents that were classified by the International Agency for Research on Cancer or European Union as being known or presumed to have CMR potential in humans. The association of individual and job characteristics with exposure prevalence, duration, and intensity of the CMR agents during a 1-week period was examined using multilevel logistic regression analysis. Overall, 10.4% of employees in 2010 were exposed to one or more CMR agents at their workplace, and 3.4% were subjected to multiple CMR exposures. Blue-collar workers, night-shift workers and workers with short-term employment contracts experienced higher exposure prevalence (p < 0.01) and intensity (p < 0.05). Bluecollar workers and shift workers experienced also longer exposure duration (p < 0.001). Conversely, managers, workers of large companies, and women were less exposed to CMR agents (p < 0.001). The presence of a Committee for Health, Safety, and Working Conditions, and intervention by Occupational Health and Safety officers were significantly associated with reduced exposure intensities (p < 0.001 and p < 0.05). Establishment of European CMR regulations and the existence of an applicable substitution principle reduced the exposure duration (p < 0.001) and intensity (p < 0.05). Our results point out disparities in CMR exposure and identify high-priority targets for prevention measures to help reducing social health discrepancies.

Mutagenicity of Flavonoids Assayed by Bacterial Reverse Mutation (Ames Test

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Eliana Aparecida Varanda

2012-05-01

Full Text Available The mutagenicity of ten flavonoids was assayed by the Ames test, in Salmonella typhimurium strains TA98, TA100 and TA102, with the aim of establishing hydroxylation pattern-mutagenicity relationship profiles. The compounds assessed were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone. In the Ames assay, quercetin acted directly and its mutagenicity increased with metabolic activation. In the presence of S9 mix, kaempferol and galangin were mutagenic in the TA98 strain and kaempferol showed signs of mutagenicity in the other strains. The absence of hydroxyl groups, as in flavone, only signs of mutagenicity were shown in strain TA102, after metabolization and, among monohydroxylated flavones (3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone, the presence of hydroxyl groups only resulted in minor changes. Luteolin and fisetin also showed signs of mutagenicity in strain TA102. Finally, chrysin, which has only two hydroxy groups, at the 5-OH and 7-OH positions, also did not induce mutagenic activity in any of the bacterial strains used, under either activation condition. All the flavonoids were tested at concentrations varying from 2.6 to 30.7 nmol/plate for galangin and 12.1 to 225.0 nmol/plate for other flavonoids. In light of the above, it is necessary to clarify the conditions and the mechanisms that mediate the biological effects of flavonoids before treating them as therapeutical agents, since some compounds can be biotransformed into more genotoxic products; as is the case for galangin, kaempferol and quercetin.

Cytotoxicity and mutagenicity of opthalmic solution preservatives and UVA radiation in L5178Y cells

International Nuclear Information System (INIS)

Withrow, T.J.; Brown, N.T.; Hitchins, V.M.; Strickland, A.G.

1989-01-01

Four preservatives used in ophthalmic solutions were tested for toxic and mutagenic potential in mouse lymphoma cells with and without exposure of cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediaminetetraacetic acid (EDTA). Cell survival and mutagenesis were measured using the L5178Y mouse lymphoma (TK +/- ) system. Cells were exposed to varying amounts of preservatives for 1 h at 37 0 C, and aliquots irradiated with UVA radiation (during exposure to preservative). Cells were then assayed for survival, and mutagenesis at the thymidine kinase (TK) locus. In concentrations commonly found in ophthalmic solutions, BAK, chlorhexidine, and thimerosal were toxic to cells, and thimerosal was slightly mutagenic. When cells were exposed to preservative and UVA radiation, chlorhexidine was mutagenic and the mutagenic activity of thimerosal was enhanced. (author)

Cytotoxicity and mutagenicity of opthalmic solution preservatives and UVA radiation in L5178Y cells

Energy Technology Data Exchange (ETDEWEB)

Withrow, T.J.; Brown, N.T.; Hitchins, V.M.; Strickland, A.G. (Food and Drug Administration, Rockville, MD (USA). Center for Devices and Radiological Health)

1989-09-01

Four preservatives used in ophthalmic solutions were tested for toxic and mutagenic potential in mouse lymphoma cells with and without exposure of cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediaminetetraacetic acid (EDTA). Cell survival and mutagenesis were measured using the L5178Y mouse lymphoma (TK{sup +/-}) system. Cells were exposed to varying amounts of preservatives for 1 h at 37{sup 0}C, and aliquots irradiated with UVA radiation (during exposure to preservative). Cells were then assayed for survival, and mutagenesis at the thymidine kinase (TK) locus. In concentrations commonly found in ophthalmic solutions, BAK, chlorhexidine, and thimerosal were toxic to cells, and thimerosal was slightly mutagenic. When cells were exposed to preservative and UVA radiation, chlorhexidine was mutagenic and the mutagenic activity of thimerosal was enhanced. (author).

Chemical carcinogenic and mutagenic agents in the workplace, Poland, 2008–2010

Directory of Open Access Journals (Sweden)

Katarzyna Konieczko

2013-04-01

Full Text Available Background: The aim of this paper is to present a concise but comprehensive information on the occurrence of carcinogenic or mutagenic agents in Polish enterprises and the number of workers exposed to those agents reported to the central register by employers. Objectives and responsibilities of the register, as well as the range and methods of data gathering are discussed. Material and Methods: Data concerning carcinogenic or mutagenic chemical substances and technological processes reported to central register in 2008-2010 were analyzed. Results: In 2008-2010 more than 300 carcinogenic or mutagenic chemical substances were reported to the register. Approximately 2500 plants reported above 150 000 per-person-exposures annually. Among all technological processes regarded as occupational carcinogens, hardwood dusts exposure (about 660 companies; 11 000-13 000 exposed workers each year and exposure to polycyclic aromatic hydrocarbons (PAHs present in coal products (117-125 plantsl 3000 exposed per year were reported. Conclusions: The most widespread carcinogenic/mutagenic substances were: benzene, chromium(VI compounds: potassium dichromate and chromate, chromium(VI trioxide and other chromium compounds, ethylene oxide, asbestos, benzo[a]pyrene and gasoline. The highest number of men was exposed to particular PAHs and benzene , and the majority of women was exposed to benzene, potassium dichromate and chromate, acrylamide, ethylene oxide and gasoline. The lack of clear-cut definitione of occupational exposure to carcinogen creates a problem faced by employers in defining the accurate number of exposed workers. Med Pr 2013;64(2:181–192

AN OVERVIEW OF MUTAGENIC POTENTIAL OF PESTICIDES

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Aurel Popescu

2013-12-01

Full Text Available This paper presents a synthesis of mutagenic potential of a few pesticides. Cytotoxicity tests, using plant test systems in vivo, such as Allium cepa, are validated by the similar results performed in animal testing in vitro. Cytogenetic tests are usefulness for identifying and evaluating the damaging effects of pesticides present in various concentrations under different exposure times on living organisms. Mutagenic potential of different pesticides used can be detected cytologically by cellular inhibition (mitotic index and replication index are used as indicators of adequate cell proliferation, disruption in metaphase, induction of chromosomal aberrations, numerical and structural, ranging from chromosomal fragmentation to the disorganization of the mitotic spindle, and consequently of all subsequent dependent mitotic phases.

Evaluation of the tickcide, genotoxic, and mutagenic effects of the Ruta graveolens L. (Rutaceae

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Alessandra Vargas de Carvalho

2015-10-01

Full Text Available Current analysis investigated the tickcide effects of the aqueous extract and chloroform fractions of Ruta graveolens L. (rue on engorged females of Rhipicephalus microplus, as well as their genotoxic and mutagenic effects on human leukocytes. The best tickcide activity (non-dependent dose and genotoxic / mutagenic effects (dependent-dose were observed on exposure to chloroform fractions. Results suggest that extract fractions of R. graveolens L are efficient against R. microplus, although the fraction and the tested concentrations show genotoxic and mutagenic potential for human leukocytes.

Toxicity and mutagenicity of exhaust from compressed natural gas: Could this be a clean solution for megacities with mixed-traffic conditions?

Science.gov (United States)

Agarwal, Avinash K; Ateeq, Bushra; Gupta, Tarun; Singh, Akhilendra P; Pandey, Swaroop K; Sharma, Nikhil; Agarwal, Rashmi A; Gupta, Neeraj K; Sharma, Hemant; Jain, Ayush; Shukla, Pravesh C

2018-04-20

Despite intensive research carried out on particulates, correlation between engine-out particulate emissions and adverse health effects is not well understood yet. Particulate emissions hold enormous significance for mega-cities like Delhi that have immense traffic diversity. Entire public transportation system involving taxis, three-wheelers, and buses has been switched from conventional liquid fuels to compressed natural gas (CNG) in the Mega-city of Delhi. In this study, the particulate characterization was carried out on variety of engines including three diesel engines complying with Euro-II, Euro-III and Euro-IV emission norms, one Euro-II gasoline engine and one Euro-IV CNG engine. Physical, chemical and biological characterizations of particulates were performed to assess the particulate toxicity. The mutagenic potential of particulate samples was investigated at different concentrations using two different Salmonella strains, TA98 and TA100 in presence and absence of liver S9 metabolic enzyme fraction. Particulates emitted from diesel and gasoline engines showed higher mutagenicity, while those from CNG engine showed negligible mutagenicity compared to other test fuels and engine configurations. Polycyclic aromatic hydrocarbons (PAHs) adsorbed onto CNG engine particulates were also relatively fewer compared to those from equivalent diesel and gasoline engines. Taken together, our findings indicate that CNG is comparatively safer fuel compared to diesel and gasoline and can offer a cleaner transport energy solution for mega-cities with mixed-traffic conditions, especially in developing countries. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mutagenic effects of alkylating agents on prophage lambda

Energy Technology Data Exchange (ETDEWEB)

Bresler, S.; Kalinin, V.L.; Kuznetsova, L.V.

1984-06-01

An evaluation was made of the relative contribution of repair and reparative mechanisms to the mutagenic potency of several alkylating agents on thermoinducible prophage lambdacI857 ind/sup -/ in several stains of E. coli. Following treatment of lysogenic E. coli with the mutagens and heat induction, 0.02 N-nitroso-N-methylurea (NMU) induced c mutations with a high frequency (ca. 10%) in both wild type E. coli and cells with repair mutations (recA13, lexA102, uvrA6, umuC36, xthA9, recF143, polA1, uvrD3, uvrD502). It appears that NUM-induced mutations are stabilized as replicative errors due to mismatched, altered bases. Delay in induction following exposure to NMU improves prophage survival and diminishes c mutant formation, regardless of the E. coli genotype. Evidently, carbamoylation is not involved in NMU mutagenicity since 0.02 M KNCO is nonmutagenic and is virtually without effect on prophage viability. Replicative mechanisms are also involved in N-methyl-N'-nitro-N-nitrosoguanidine (15%) and ethyl methanesulfonate (2%) induced mutations, since the maximum yield of mutants was independent of recA/sup +/ genotype. However, the mutagenicity of methyl methanesulfonate was abolished by the recA mutation, indicating that the mutagenicity of this agent is repair-dependent. Mitomycin C (0.1%) and acridine mustard (0.3%) induce c mutations regardless of recA/sup +/ and, therefore, appear to do so by intercalation. 26 references, 6 figures.

Heterocyclic amines: Mutagens/carcinogens produced during cooking of meat and fish.

Science.gov (United States)

Sugimura, Takashi; Wakabayashi, Keiji; Nakagama, Hitoshi; Nagao, Minako

2004-04-01

Research leading to the discovery of a series of mutagenic and carcinogenic heterocyclic amines (HCAs) was inspired by the idea that smoke produced during cooking of food, especially meat or fish, might be carcinogenic. More than ten kinds of HCAs, actually produced by cooking or heating of meat or fish, have now been isolated and their structures determined, most being previously unregistered compounds. They are highly mutagenic towards Salmonella typhimurium in the presence of S9 mix and are also mutagenic in vitro and in vivo toward mammalian cells. HCAs have now been chemically synthesized in quantity and subjected to long-term animal testing. When HCAs were fed in the diet, rodents developed cancers in many organs, including the colon, breast and prostate, and one HCA produced hepatomas in monkeys. The lesions exhibited alteration in genes including Apc, beta-catenin and Ha-ras, and these changes provide clues to the induction mechanisms. The HCAs are oxidized to hydroxyamino derivatives by cytochrome P450s, and further converted to ester forms by acetyltransferase and sulfotransferase. Eventually, they produce DNA adducts through the formation of N-C bonds at guanine bases. There are HCA-sensitive and resistant strains of rodents and a search for the responsible genes is now under way. While the content of HCAs in dishes consumed in ordinary life is low and not sufficient in itself to explain human cancer, the coexistence of many other mutagens/carcinogens of either autobiotic or xenobiotic type and the possibility that HCAs induce genomic instability and heightened sensitivity to tumor promoters suggest that avoidance of exposure to HCAs or reduction of HCAs' biological effects as far as possible are to be highly recommended. Usage of microwave ovens for cooking and supplementation of the diet, for example with soy-isoflavones, which have been found to suppress the occurrence of HCA-induced breast cancers, should be encouraged. Advice to the general public

Mutagenic activities of a chlorination by-product of butamifos, its structural isomer, and their related compounds.

Science.gov (United States)

Kamoshita, Masahiro; Kosaka, Koji; Endo, Osamu; Asami, Mari; Aizawa, Takako

2010-01-01

The mutagenic activities of 5-methyl-2-nitrophenol (5M2NP), a chlorination by-product of butamifos, its structural isomer 2-methyl-5-nitrophenol (2M5NP), and related compounds were evaluated by the Ames assay. The mutagenic activities of 5M2NP and 2M5NP were negative or not particularly high. However, those of their chlorinated derivatives were increased in Salmonella typhimurium strain TA100 and the overproducer strains YG1026, and YG1029 in the absence and/or presence of a rat liver metabolic activation system (S9 mix), particularly for YG1029. The mutagenic activities of 6-chloro-2-methyl-5-nitrophenol (6C2M5NP) in YG1029 in the absence and presence of S9 mix were 70000 and 110000 revertants mg(-1), respectively. When nitro functions of 6C2M5NP and 4-chloro-5-methyl-2-nitrophenol (4C5M2NP) were reduced to amino functions, their mutagenic activities were markedly decreased. The mutagenic activities of 5M2NP and 4C5M2NP were lower than those of 2M5NP and 6C2M5NP, respectively. Thus, it was shown that substituent position is a key factor for the mutagenic activities of methylnitrophenols (MNPs) and related compounds. The mutagenic activities of the extracts of 2M5NP in chlorination increased early during the reaction time and then decreased. The main chlorination by-product contributing to the mutagenic activities of the extracts of 2M5NP in chlorination was 6C2M5NP. The results of chlorination of 2M5NP suggested that MNPs were present as their dichlorinated derivatives or further chlorination by-products in drinking water. Copyright 2009 Elsevier Ltd. All rights reserved.

Assessment of diphenylcyclopropenone for photochemically induced mutagenicity in the Ames assay

Energy Technology Data Exchange (ETDEWEB)

Wilkerson, M.G.; Connor, T.H.; Henkin, J.; Wilkin, J.K.; Matney, T.S.

1987-10-01

The photochemical conversion of diphenylcyclopropenone to diphenylacetylene has recently been reported. Diphenylcyclopropenone is used in the treatment of alopecia areata and is nonmutagenic in a limited Ames assay. We examined diphenylcyclopropenone and diphenylacetylene, as well as synthetic precursors of diphenylcyclopropenone--dibenzylketone and alpha,alpha'-dibromodibenzylketone--for mutagenicity against TA100, TA98, TA102, UTH8413, and UTH8414. All compounds were nonmutagenic except alpha,alpha'-dibromodibenzylketone, which was a potent mutagen in TA100 with and without S-9 activation. The effect of photochemical activation of diphenylcyclopropenone in the presence of bacteria demonstrated mutagenicity in UTH8413 (two times background) at 10 micrograms/plate with S-9 microsomal activation. 8-Methoxypsoralen produces a mutagenic response in TA102 at 0.1 microgram/plate with 60 seconds of exposure to 350 nm light. In vitro photochemically activated Ames assay with S-9 microsomal fraction may enhance the trapping of short-lived photochemically produced high-energy mutagenic intermediates. This technique offers exciting opportunities to trap high-energy intermediates that may play an important role in mutagenesis. This method can be applied to a variety of topically applied dermatologic agents, potentially subjected to photochemical changes in normal use.

Mutagenicity of smoke condensates from Canadian cigarettes with different design features.

Science.gov (United States)

Mladjenovic, Nemanja; Maertens, Rebecca M; White, Paul A; Soo, Evelyn C

2014-01-01

There is currently limited knowledge regarding the impact of different cigarette designs on the toxicological properties of cigarette smoke condensate (CSC). This study used the Salmonella Mutagenicity Assay to examine the mutagenic activity of mainstream CSCs from 11 commercial Canadian cigarette brands with different design features or tobacco blend. The brands were selected to include design features that are common for cigarettes sold in the Canadian market, as well as cigarettes with alternate filters (charcoal or MicroBlue™), the super slim design, and cigarettes containing mixed blends of different tobacco types. CSCs were obtained using the International Organization for Standardization (ISO) and Health Canada Intense (HCI) smoking regimes, and mutagenic activity was assessed using Salmonella strains TA98, YG1041 and YG5185. Comparisons of the commercial brands to the Kentucky 3R4F, the Canadian Monitor 8 reference and a Canadian best seller revealed no significant reduction in CSC mutagenicity for cigarettes with alternate filters. However, the super slim design did afford some reduction in mutagenic potency. Nevertheless, since the study did not attempt to evaluate the impact of the cigarette designs on human health at the individual or population level, the super slim cigarettes cannot be considered 'reduced-harm' cigarettes.

Mutagenicity in drug development: interpretation and significance of test results.

Science.gov (United States)

Clive, D

1985-03-01

The use of mutagenicity data has been proposed and widely accepted as a relatively fast and inexpensive means of predicting long-term risk to man (i.e., cancer in somatic cells, heritable mutations in germ cells). This view is based on the universal nature of the genetic material, the somatic mutation model of carcinogenesis, and a number of studies showing correlations between mutagenicity and carcinogenicity. An uncritical acceptance of this approach by some regulatory and industrial concerns is over-conservative, naive, and scientifically unjustifiable on a number of grounds: Human cancers are largely life-style related (e.g., cigarettes, diet, tanning). Mutagens (both natural and man-made) are far more prevalent in the environment than was originally assumed (e.g., the natural bases and nucleosides, protein pyrolysates, fluorescent lights, typewriter ribbon, red wine, diesel fuel exhausts, viruses, our own leukocytes). "False-positive" (relative to carcinogenicity) and "false-negative" mutagenicity results occur, often with rational explanations (e.g., high threshold, inappropriate metabolism, inadequate genetic endpoint), and thereby confound any straightforward interpretation of mutagenicity test results. Test battery composition affects both the proper identification of mutagens and, in many instances, the ability to make preliminary risk assessments. In vitro mutagenicity assays ignore whole animal protective mechanisms, may provide unphysiological metabolism, and may be either too sensitive (e.g., testing at orders-of-magnitude higher doses than can be ingested) or not sensitive enough (e.g., short-term treatments inadequately model chronic exposure in bioassay). Bacterial systems, particularly the Ames assay, cannot in principle detect chromosomal events which are involved in both carcinogenesis and germ line mutations in man. Some compounds induce only chromosomal events and little or no detectable single-gene events (e.g., acyclovir, caffeine

Using the Salmonella assay to delineate the dispersion routes of mutagenic compounds from coal wastes in contaminated soil.

Science.gov (United States)

da Silva Júnior, Flavio Manoel Rodrigues; Vargas, Vera Maria Ferrão

2009-03-17

The mutagenicity of acidic and organic extracts of surface soil under the influence of a coal-fired power plant was evaluated by Salmonella/microsome assay using strains TA97a, TA98 and TA100 in the absence and presence of exogenous metabolic systems (S9 mix). Additionally, strains YG1041 and YG1042 (sensitive to nitroderivatives) were used for the organic extracts. In general, the responses were higher in the organic extracts in the presence of S9 mix. The comparison between strains TA98 and TA100 and their derived strains YG1041 and YG1042, respectively, allowed the detection of the presence of nitro-aromatic compounds in some sampling areas, which was confirmed by chemical analysis. The interpretation of the set of mutagenesis data suggests that there are two important mutagenic compound dispersion routes in the area of study: frameshift mutagens were dispersed predominantly by runoff and leaching, while base-pair substitution mutagens were dispersed mainly by the atmosphere. This mutagenic damage might be attributed to the effects of several substances detected in the area, such as aliphatic hydrocarbons and the metals aluminum, cadmium, lead and iron.

Assessment of the mutagenic potential of cyanobacterial extracts and pure cyanotoxins.

Science.gov (United States)

Sieroslawska, Anna

2013-11-01

The aim of the study was to assess the mutagenic potential of extracts obtained from the cyanobacterial bloom-forming cells harvested from the water body located in Lubelszczyzna region of southeastern Poland. Three cyanotoxins, microcystin-LR, cylindrospermopsin and anatoxin-a were detected in some of the studied samples in different concentrations. All extracts were assessed for their potential mutagenic effects with the use of a short-term bacterial assay, the Ames test. Mutagenic activity was observed in four of all ten studied extracts, mainly toward the Salmonella typhimurium TA100 strain. On the contrary, the cyanotoxins in purified forms occurred not to be mutagenic or cytotoxic towards S. typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2 uvrA and WP2 [pKM101] up to a concentration of 10 μg/ml. Similarly, there were no effects after bacteria exposure to the mixture of purified toxins. It has been also detected that after fractionation, genotoxic impact of previously mutagenic extracts was weaker and the highest potency in revertant induction possessed fractions containing very hydrophilic compounds. The results indicate, that while tested cyanotoxins were not directly responsible for the observed mutagenicity of the extracts analysed, some synergistic interactions with other unidentified cyanobacterial-derived factors involved in the process are possible. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mutagenic effect of cadmium on tetranucleotide repeats in human cells

Energy Technology Data Exchange (ETDEWEB)

Slebos, Robbert J.C. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States) and Department of Otolaryngology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States)]. E-mail: r.slebos@vanderbilt.edu; Li Ming [Department of Biostatistics, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Evjen, Amy N. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Coffa, Jordy [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Shyr, Yu [Department of Biostatistics, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Yarbrough, Wendell G. [Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States); Department of Otolaryngology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 (United States)

2006-12-01

Cadmium is a human carcinogen that affects cell proliferation, apoptosis and DNA repair processes that are all important to carcinogenesis. We previously demonstrated that cadmium inhibits DNA mismatch repair (MMR) in yeast cells and in human cell-free extracts (H.W. Jin, A.B. Clark, R.J.C. Slebos, H. Al-Refai, J.A. Taylor, T.A. Kunkel, M.A. Resnick, D.A. Gordenin, Cadmium is a mutagen that acts by inhibiting mismatch repair, Nat. Genet. 34 (3) (2003) 326-329), but cadmium also inhibits DNA excision repair. For this study, we selected a panel of three hypermutable tetranucleotide markers (MycL1, D7S1482 and DXS981) and studied their suitability as readout for the mutagenic effects of cadmium. We used a clonal derivative of the human fibrosarcoma cell line HT1080 to assess mutation levels in microsatellites after cadmium and/or N-methyl-N-nitro-N-nitrosoguanidine (MNNG) exposure to study effects of cadmium in the presence or absence of base damage. Mutations were measured in clonally expanded cells obtained by limiting dilution after exposure to zero dose, 0.5 {mu}M cadmium, 5 nM MNNG or a combination of 0.5 {mu}M cadmium and 5 nM MNNG. Exposure of HT1080-C1 to cadmium led to statistically significant increases in microsatellite mutations, either with or without concurrent exposure to MNNG. A majority of the observed mutant molecules involved 4-nucleotide shifts consistent with DNA slippage mutations that are normally repaired by MMR. These results provide evidence for the mutagenic effects of low, environmentally relevant levels of cadmium in intact human cells and suggest that inhibition of DNA repair is involved.

Induced mutations in chickpea (Cicer arietinum L.) I. comparative mutagenic effectiveness and efficiency of physical & chemical mutagens

International Nuclear Information System (INIS)

Kharkwal, M.C.

1998-01-01

Mutagenic effectiveness usually means the rate of mutation as related to dose. Mutagenic efficiency refers to the mutation rate in relation to damage. Studies on comparative mutagenic effectiveness and efficiency of two physical (gamma rays and fast neutrons) and two chemical mutagens (NMU and EMS) on two desi (G 130 & H 214), one kabuli (C 104) and one green seeded (L 345) chickpea (Cicer arietinum L.) have been reported. The treatments included three doses each of gamma rays (400, 500 and 600 Gy) and fast neutrons (5, 10 and 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU 0.01% 20h and 0.02% 8h) and EMS (0.1% 20h and 0.2% 8h). Results indicated that chemical mutagens, particularly NMU are not only more effective but also efficient than physical mutagens in inducing mutations in chickpea. Mutagenic effectiveness and efficiency showed differential behaviour depending upon mutagen and varietal type. Chemical mutagens were more efficient than physical in inducing cholorophyll as well as viable and total number of mutations. Among the mutagens NMU was the most potent, while in the physical, gamma rays were more effective. Out of four mutagens, NMU was the most effective and efficient in inducing a high frequency and wide spectrum of chlorophyll mutations in the M2 followed by fast neutrons. While gamma rays showed least effectiveness, EMS was least efficient mutagens. Major differences in the mutagenic response of the four cultivars were observed. The varieties of desi type were more resistant towards mutagenic treatment than kabuli and green seeded type

Quantitative mammalian cell mutagenesis and mutagen screening: study with CHO cells

International Nuclear Information System (INIS)

Hsie, A.W.; O'Neill, J.P.; San Sebastian, J.R.; Brimer, P.A.

1979-01-01

The CHO/HGPRT system has been developed and defined for quantifying mutation induced by various physical and chemical agents at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in Chinese hamster ovary (CHO) cells. In all direct-acting chemical mutagens studied, mutation induction increases linearly as a function of the concentration, with no apparent threshold. Some chemicals induce mutation at non-cytotoxic concentrations. The mutagenicity of ethyl methanesulfonate has been quantified as a function of exposure concentration x treatment time. The sensitive and quantitative nature of the system enables studies of the structure-activity (mutagenicity) relationships of various classes of chemicals, including alkylating agents, heterocyclic nitrogen mustards, and platinum compounds. When rat liver S 9 -mediated metabolic activation is present, procarcinogens such as benzo(a)pyrene, 2-acetylaminofluorene, and dimethylnitrosamine are mutagenic, whereas their noncarcinogenic structural analogues pyrene, fluorene, and dimethylamine are not. The system has been shown to be useful in determining the interactive effects between physical and chemical agents, and in screening for mutagenicity of fractionated organic mixtures and industrial chemicals in both liquid and gaseous state. For the system to be used successfully in routine screening, further studies should be directed toward the development of a metabolic activation system suitable for a broad spectrum of chemicals, a sensitive and reliable statistical method, and an experimental design to determine compounds with low mutagenicity. The system has been expanded for determination of mutagen-induced chromosome aberration, sister-chromatid exchange, and micronucleus formation in addition to gene mutation and cytotoxicity; it can also be used to study inhibition of DNA synthesis

New approaches to assessing the effects of mutagenic agents on the integrity of the human genome

International Nuclear Information System (INIS)

Elespuru, R.K.; Sankaranarayanan, K.

2007-01-01

Heritable genetic alterations, although individually rare, have a substantial collective health impact. Approximately 20% of these are new mutations of unknown cause. Assessment of the effect of exposures to DNA damaging agents, i.e. mutagenic chemicals and radiations, on the integrity of the human genome and on the occurrence of genetic disease remains a daunting challenge. Recent insights may explain why previous examination of human exposures to ionizing radiation, as in Hiroshima and Nagasaki, failed to reveal heritable genetic effects. New opportunities to assess the heritable genetic damaging effects of environmental mutagens are afforded by: (1) integration of knowledge on the molecular nature of genetic disorders and the molecular effects of mutagens; (2) the development of more practical assays for germline mutagenesis; (3) the likely use of population-based genetic screening in personalized medicine

Molecular dosimetry of the chemical mutagen ethyl methanesulfonate

International Nuclear Information System (INIS)

Zeeland, A.A. van; Aaron, C.S.; Mohn, G.R.; Hung, C.Y.; Brockman, H.E.

1983-01-01

Extending previous work with E. coli and mammalian cells in culture, forward-mutation frequencies induced by ethyl methanesulfonate (EMS) were quantitatively compared in Neurospora crassa and Saccharomyces cerevisiae under standardized conditions. Concomitantly, the actual dose to DNA was measured by determining the amount of radioactivity bound to DNA after treatment with tritium-labeled EMS. After exposure to EMS (2.5-50 mM), alkylation levels in N. crassa and S. cerevisiae were similar to those previously determined in E. coli and cultured mammalian cells. Consistently, there was a slightly less than proportional increase of the DNA alkylation level with the exposure concentration of the mutagen. Forward mutagenesis induced in yeast and N. crassa showed exponential kinetics with exponents of 1.5 and 2.6, respectively. These results are similar to those previously reported with E. coli, which differed from the results with cultured mammalian cells, where a linear dose-effect relationship between exposure and genetic effect was observed. These differences may reflect differences in the fate of EMS-induced adducts by cellular DNA repair systems, but are not due to initial differences in DNA alkylation levels. The fate and persistence of specific DNA adducts potentially responsible for pre-mutagenic changes are under investigation. (orig.)

Mutagenic and genotoxic activity of particulate matter MP2,5, in Pamplona, North Santander, Colombia

OpenAIRE

Martínez Montañez, Mónica Liseth; Meléndez Gélvez, Iván; Quijano Parra, Alfonso

2012-01-01

Objective: To study the mutagenic and genotoxic activities of particulate material (MP2,5 collected in Pamplona, Norte de Santander, Colombia.Materials and methods: MP2,5 was monitored by means of a Partisol 2025 sequential air sampler with Plus Palmflex quartz filters. The latter were subjected to two extraction procedures: Soxhlet extraction using dichloromethane-acetone; and ultrasonic extraction using dichloromethane, acetone and dichloromethane/ acetone mix. The mutagenic and genotoxic a...

Environmental tobacco smoking, mutagen sensitivity, and head and neck squamous cell carcinoma.

Science.gov (United States)

Zhang, Z F; Morgenstern, H; Spitz, M R; Tashkin, D P; Yu, G P; Hsu, T C; Schantz, S P

2000-10-01

Although active tobacco smoking has been considered a major risk factor for head and neck cancer, few studies have evaluated environmental tobacco smoke (ETS) and its interaction with mutagen sensitivity on the risk of head and neck cancer. We investigated the relationship between ETS and head and neck cancer in a case-control study of 173 previously untreated cases with pathologically confirmed diagnoses of squamous cell carcinoma of the head and neck and 176 cancer-free controls at Memorial Sloan-Kettering Cancer Center between 1992 and 1994. A structured questionnaire was used to collect ETS exposure and other covariates including a history of active tobacco smoking and alcohol use. ETS measures include a history of ETS exposure at home and at workplace. The associations between passive smoking and head and neck cancer were analyzed by Mantel-Haenszel methods and logistic regression models. Additive and multiplicative models were used to evaluate effect modifications between ETS and mutagen sensitivity. The crude odds ratio (OR) for ETS exposure was 2.8 [95% confidence intervals (CI), 1.3-6.0]. Controlling for age, sex, race, education, alcohol consumption, pack-years of cigarette smoking, and marijuana use, the risk of squamous cell carcinoma of the head and neck was increased with ETS (adjusted OR, 2.4; 95% CI, 0.9-6.8). Dose-response relationships were observed for the degree of ETS exposure; the adjusted ORs were 2.1 (95% CI, 0.7-6.1) for those with moderate exposure and 3.6 (95% CI, 1.1-11.5) for individuals with heavy exposure (P for trend = 0.025), in comparison with those who never had ETS exposures. These associations and the dose-response relationships were still present when the analysis was restricted to nonactive smoking cases and controls (crude OR, 2.2; 95% CI, 0.6-8.4). Crude odds ratios were 1.8 for those with moderate ETS exposure and 4.3 for individuals with heavy ETS exposure among nonsmoking cases and controls (P for trend = 0.008). More

Quantitative measures of mutagenicity and multability based on mutant yield data

International Nuclear Information System (INIS)

Eckhardt, F.; Haynes, R.H.

1980-01-01

We describe, how mutant yield data (mutants per cell treated) can be used both to compare the mutagenenicity of different mutagens, and to characterize the mutability of different cell types. Yield curves reveal the net effect of the lethal and genetic actions of mutagens on cells. Normally, yields are the quantities measured in assays for mutagenesis, and rectilinear plots of such data baldly reveal the amount of experimental error and the extent of actual mutant induction above the background level. Plots of yield versus lethal hits can be used to quantify the relative mutagenenic efficiency (RME) of agents whose physical exposure doses otherwise would be incommensurable, as well as the relative mutability (Rmt) of different strains to the same mutagen. Plots of yield versus log dose provide an unambiguous way of assessing the relative mutational sensitivities (Rms) and mutational resolutions (Rmr) of different strains against a given mutagen. Such analysis is important for evaluation of the relative merits of excision-proficient and excision-deficient strains of the same organism as mutagen-testing systems. The mathematical approach outlined here is applied, by way of example, to measurements of UV and 4-NQO induced mutagenesis in both repair-deficient and repair-proficient haploid strains of the yeast Sacccharomyces cerevsiae. (orig.)

Evaluation of extracellular products and mutagenicity in cyanobacteria cultures separated from a eutrophic reservoir

International Nuclear Information System (INIS)

Huang, W.-J.; Lai, C.-H.; Cheng, Y.-L.

2007-01-01

The algal extracellular products (ECPs) in three cultures of cyanobacteria species (Anabaena, Microcystis, and Oscillatoria) dominating the eutrophic reservoir populations and their toxins have been investigated in the present work. Using gas chromatography coupled with high-resolution electron-impact mass spectrometry (GC/EI-MS) and high performance anion-exchange chromatography (HPAEC) techniques, more than 20 compounds were found in the algal culture (including cells and filtrates) extracts. The main identified ECPs were classified to polysaccharides, hydrocarbons, and aldehydes. Odor causing substances such as trans-1,10-dimethyl-trans-9-decalol (geosmin) and 2-methylisoborneol (2-MIB)were also found in the algal cultures. The potential mutagenicity of the algal suspensions was also studied with the Ames test. The organic extracts of the algal suspension from the axenic cultures were mutagenicity in TA98 without S9 mix and in TA100 with and without S9 mix. The results indicate that the ECPs of three algae species dominating the eutrophic reservoir were mutagenic clearly in the bacterial test

Carcinogenicity and mutagenicity of chromium.

Science.gov (United States)

Léonard, A; Lauwerys, R R

1980-11-01

Occupational exposure represents the main source of human contamination by chromium. For non-occupationally exposed people the major environmental exposure to chromium occurs as a consequence of its presence in food. Chromium must be considered as an essential element. Its deficiency impairs glucose metabolism. Trivalent chromium salts are poorly absorbed through the gastro-intestinal and respiratory tracts because they do not cross membranes easily. Hexavalent chromium can be absorbed by the oral and pulmonary routes and probably also through the skin. After its absorption, hexavalent chromium is rapidly reduced to the trivalent form which is probably the only form to be found in biological material. Epidemiological studies have shown that some chromium salts (mainly the slightly soluble hexavalent salts) are carcinogens. Lung cancers have, indeed, often been reported among workers in chromate-producing industry and, to a lesser extent, in workers from the chrome-pigment industry. The first attempts to produce cancers in experimental animals by inhalation or parenteral introduction gave negative or equivocal results but, from 1960, positive results have been obtained with various chromium compounds. As for the carcinogenic activity, the mutagenicity of chromium has mainly been found with hexavalent salts. In the majority of assay systems used, trivalent chromium appears inactive. It can be considered as evident, however, that the ultimate mutagen which binds to the genetic material is the trivalent form produced intracellularly from hexavalent chromium, the apparent lack of activity of the trivalent form being due to its poor cellular uptake.

Environmental chemical mutagens and genetic risks: Lessons from radiation genetics

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1996-01-01

The last three decades have witnessed substantial progress in the development and use of a variety of in vitro and in vivo assay systems for the testing of environmental chemicals which may pose a mutagenic hazard to humans. This is also true of basic studies in chemical mutagenesis on mechanisms, DNA repair, molecular dosimetry, structure-activity relationships, etc. However, the field of quantitative evaluation of genetic risks of environmental chemicals to humans is still in it infancy. This commentary addresses the question of how our experience in estimating genetic risks of exposure to ionizing radiation can be helpful in similar endeavors with environmental chemical mutagens. 24 refs., 3 tabs

Genotoxicity studies in semiconductor industry. 1. In vitro mutagenicity and genotoxicity studies of waste samples resulting from plasma etching

Energy Technology Data Exchange (ETDEWEB)

Braun, R.; Huettner, E.M.; Merten, H.; Raabe, F. (Institute of Plant Genetics and Crop Plant Research, Gatersleben (Germany))

1993-07-01

Solid waste samples taken from the etching reactor, the turbo pump, and the waste air system of a plasma etching technology line in semiconductor production were studied as to their genotoxic properties in a bacterial repair test, in the Ames/Salmonella microsome assay, in the SOS chromotest, in primary mouse hepatocytes, and in Chinese hamster V79 cell cultures. All three waste samples were found to be active by inducing of unscheduled DNA-synthesis in mouse hepatocytes in vitro. In the bacterial rec-type repair test with Proteus mirabilis, waste samples taken from the turbo pump and the vacuum pipe system were not genotoxic. The waste sample taken from the chlorine-mediated plasma reactor was clearly positive in the bacterial repair assay and in the SOS chromotest with Escherichia coli. Mutagenic activity was demonstrated for all samples in the presence and absence of S9 mix made from mouse liver homogenate. Again, highest mutagenic activity was recorded for the waste sample taken from the plasma reactor, while samples collected from the turbo pump and from the waste air system before dilution and liberation of the air were less mutagenic. For all samples chromosomal damage in V79 cells was not detected, indicating absence of clastogenic activity in vitro. Altogether, these results indicate generation of genotoxic and mutagenic products as a consequence of chlorine-mediated plasma etching in the microelectronics industry and the presence of genotoxins even in places distant from the plasma reactor. Occupational exposure can be expected both from the precipitated wastes and from chemicals reaching the environment with the air stream.

Mutagenicity of cooked foods. Kuumennuskaesiteltyjen elintarvikkeiden mutageenisuus

Energy Technology Data Exchange (ETDEWEB)

Tikkanen, L. (Valtion teknillinen tutkimuskeskus, Espoo (Finland). Elintarvikelaboratorio)

1989-09-01

In this study the mutagenic activity in different kinds of ordinary Finnish foods was determined using mainly the Ames Salmonella bacterial assay. The purpose of this study was also to acquire the technical capability to study cooked food mutagens and to get basic informavtion about the mutagenic activity of foods under different cooking conditions. The samples tested were different kinds of ready-to-eat foods. Products were industrially heat-processed by frying and roasting, sterilization, smoking, deep-frying, spray-drying and UHT-treatment. According to the results, the majority of the fried and roasted food samples containing meat or fish were clearly or strongly mutagenic. Some of the products processed by sterilization and deep-frying were marginally mutagenic. The effect of the frying temperature on the mutagenicity in the Ames test was studied with minced meat. The mutagenic activity of the fried meat clearly correlated with the frying temperature. There were conspicuous differences in mutagenic activity between different fried and roasted products. Charcoal-grilled fish and the surface layers of the grilled meat and chicken were strongly mutagenic. Meat and fish hamburgers were in most cases only slightly mutagenic. The mutagenic activity was stronger in the surface layers of the products than in the inside. Also reheating by frying increased the mutagenicity of meat patties clearly. Differences in mutagenic activity between equivalent products of different manufacturers were evident in many cases. Variation of the mutagenicity was most conspicuous in the grilled products. This variation indicates that the industrial processing of food has a marked effect on the mutagenic activity of the final product, which thus might be reduced by modifying the process. The solvent extraction method used in this study was more effective than the Blue-Cotton method for the isolation of mutagenic compounds.

The hair-dye reagent 2-(2',4'-diaminophenoxy)ethanol is mutagenic to Salmonella typhimurium.

Science.gov (United States)

Venitt, S; Crofton-Sleigh, C; Osborne, M R

1984-01-01

A new hair-dye ingredient, 2-(2',4'-diaminophenoxy)ethanol (2,4-DAPE), was described as being devoid of any genotoxic activity on the basis of a multi-laboratory study. Since 2,4-DAPE is a close analogue of 2,4-diaminoanisole (2,4-DAA), which is mutagenic and carcinogenic, we tested this claim by assaying 2,4-DAPE for bacterial mutagenicity. Two samples of 2,4-DAPE X 2HCl were synthesized by reduction of the corresponding dinitrophenoxyethanol and identity and purity were established by elemental analysis, NMR spectrometry, mass-spectrometry, UV-spectrophotometry, TLC and HPLC. Fresh aqueous solutions of 2,4-DAPE X 2HCl were assayed in several separate plate tests using S. typhimurium TA1538, TA97, TA98 and TA100, and E. coli WP2uvrA (pKM101), 3 plates per dose and 0%, 4%, 10% and 30% Aroclor 1254-induced rat-liver S9 in S9 mixes. We obtained negative results in TA100 and E. coli. Reproducible, statistically significant dose-related increases in revertants (up to 14 times the background) were obtained in frame-shift mutants of S. typhimurium in the dose range 10-80 micrograms per plate. Mutagenicity was S9-dependent, significant increases in revertants being obtained only with 50 microliter per plate or more of S9. 2,4-DAPE induced significant mutagenic effects at doses of less than 1 micrograms per ml in TA1538 and TA98 in fluctuation tests using 2% S9 in the S9 mix. In plate tests, 2,4-DAPE was less mutagenic (by a factor of about 8) than 2,4-DAA, which gave the highest mutant yields with 20 microliter S9 per plate (4% S9 in the S9 mix). 2,4-DAPE obtained commercially was about 8 times more mutagenic than our sample of 2,4-DAPE. After purification, the commercial product, now chromatographically identical with our own sample, gave plate-test results close to those obtained for our samples of 2,4-DAPE. A review of the published reports (in which 2,4-DAPE was claimed to be inactive in a variety of short-term tests) revealed: (a) the use of protocols for bacterial

Plant composition, pharmacological properties and mutagenic evaluation of a commercial Zulu herbal mixture: Imbiza ephuzwato.

Science.gov (United States)

Ndhlala, A R; Finnie, J F; Van Staden, J

2011-01-27

Imbiza ephuzwato is a traditional herbal tonic made from a mixture of extracts of roots, bulbs, rhizomes and leaves of 21 medicinal plants and is used in traditional medicine as a multipurpose remedy. To compile and investigate the bioactivity and mutagenic effects of extracts of the 21 plant species used in the preparation of Imbiza ephuzwato herbal tonic. The 21 plant species used to make Imbiza ephuzwato herbal mixture were each investigated for their pharmacological properties. Petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of the 21 plants were evaluated against two gram-positive, two gram-negative bacteria and a fungus Candida albicans. The extracts were also evaluated for their inhibitory effects against cyclooxygenase (COX-1 and -2) and acetylcholinesterase AChE enzymes. Mutagenic effects of the water extracts were evaluated using the Ames test. Gunnera perpensa and Rubia cordifolia were the only plant species used to manufacture Imbiza ephuzwato that had water extracts which showed good antibacterial activity. The extracts of G. perpensa (EtOH), Hypericum aethiopicum (DCM) and Urginea physodes (EtOH) showed the best antifungal activity. The water extracts of H. aethiopicum, G. perpensa, Drimia robusta, Vitellariopsis marginata, Scadoxus puniceus and Momordica balsamina showed percentage inhibition of COX-1 that was over 70%. For COX-2 enzyme, the water extracts of G. perpensa, Cyrtanthus obliquus, M. balsamina and Tetradenia riparia exhibited inhibitory activity above 70%. Water extracts of G. perpensa, C. obliquus, V. marginata, Asclepias fruticosa and Watsonia densiflora showed good AChE inhibitory activity (>80%). The Ames test results revealed that all the water extracts of the 21 plant species used to make Imbiza ephuzwato were non-mutagenic towards the Salmonella typhimurium TA98 strain for the assay with and without S9 metabolic activation. In contrast, Imbiza ephuzwato showed mutagenic effects after exposure to S

Discovering human germ cell mutagens with whole genome sequencing: Insights from power calculations reveal the importance of controlling for between-family variability.

Science.gov (United States)

Webster, R J; Williams, A; Marchetti, F; Yauk, C L

2018-07-01

Mutations in germ cells pose potential genetic risks to offspring. However, de novo mutations are rare events that are spread across the genome and are difficult to detect. Thus, studies in this area have generally been under-powered, and no human germ cell mutagen has been identified. Whole Genome Sequencing (WGS) of human pedigrees has been proposed as an approach to overcome these technical and statistical challenges. WGS enables analysis of a much wider breadth of the genome than traditional approaches. Here, we performed power analyses to determine the feasibility of using WGS in human families to identify germ cell mutagens. Different statistical models were compared in the power analyses (ANOVA and multiple regression for one-child families, and mixed effect model sampling between two to four siblings per family). Assumptions were made based on parameters from the existing literature, such as the mutation-by-paternal age effect. We explored two scenarios: a constant effect due to an exposure that occurred in the past, and an accumulating effect where the exposure is continuing. Our analysis revealed the importance of modeling inter-family variability of the mutation-by-paternal age effect. Statistical power was improved by models accounting for the family-to-family variability. Our power analyses suggest that sufficient statistical power can be attained with 4-28 four-sibling families per treatment group, when the increase in mutations ranges from 40 to 10% respectively. Modeling family variability using mixed effect models provided a reduction in sample size compared to a multiple regression approach. Much larger sample sizes were required to detect an interaction effect between environmental exposures and paternal age. These findings inform study design and statistical modeling approaches to improve power and reduce sequencing costs for future studies in this area. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Mutagenic interactions between near-ultraviolet (365 nm) radiation and alkylating agents in Escherichia coli

International Nuclear Information System (INIS)

Moraes, E.C. de; Tyrell, R.M.

1981-01-01

The mutagenic interaction between near-ultrviolet (365 nm) radiation and the alkylting agents ehtyl methanesulponate (EMS) and methyl methanesulphonate (MMS) was studied in a repair-component and an excision-deficient stram of Escherichia coli. Near-UV raditation modified the metabolic response of of exposure to these chemicals and either reduced or increased their mutagenic efficiency. Based on these results, an experimental model was formulated to explain the mutagenic interactions that occur between near-UV and various agents that induce prototrophic reverants cia error-prone repair of DNA. According to this model, low doses of near-UV provoke conditions for mutation frequency decline (MFI) and lead to a mutagenic antagonism. With increasing near-Uv doses, damage to constitutive error-free repairs system increases, favouring the error-prone system and inhibiting the MFD. Under these conditions there will be a progressive decrease in antagonism until at high doses an enhancement of mutation frequency (positive interaction) will occur. (orig.)

[In vivo mutagenicity and clastogenicity of ionizing radiation in nuclear medicine

International Nuclear Information System (INIS)

1989-01-01

The overall goals of our research remains to investigate the mutagenic and clastogenic effects of exposure to low levels of ionizing radiation in human lymphocytes. We are studying hospital patients referred to a nuclear medicine department for diagnostic cardiac imaging and nuclear medicine technologists who administer radionuclides

Mutagenicity evaluation of forty-one metal salts by the umu test.

Science.gov (United States)

Yamamoto, Akiko; Kohyama, Yuko; Hanawa, Takao

2002-01-01

Metallic biomaterials implanted in a human body may corrode and wear, releasing metal ions and debris which may induce adverse reactions such as inflammation, allergy, neoplastic formation, developmental malformation, etc. Mutagenicity is a very fundamental and important toxicity related to carcinogenicity and reproductive/developmental toxicity because the damages to genes or DNA can be a cause of carcinogenesis and developmental abnormalities. However, available mutagenic data on metallic ions and compounds are restricted to the number of elements. Therefore, to obtain the systematic data necessary for metal ion mutagenicity, 41 metal salts encompassing 36 metals and 5 metallic elements tested with different valences, were evaluated on their mutagenicity by a microbial test, the umu test. As a result, K(2)Cr(2)O(7), RhCl(3), IrCl(4), and MgCl(2) are positive without metabolic activation. Concentrations having the maximum mutagenic effect (C(max)) are 9.65 x 10(-5), 1.00 x 10(-4), 3.11 x 10(-3), 4.12 x 10(-3) mol. L(-1), respectively. CuCl(2), VCl(3), CuCl, RhCl(3), K(2)Cr(2)O(7), and IrCl(4) are positive with metabolic activation by S-9 mix with C(max) of 1.60 x 10(-5), 3.91 x 10(-5), 1.57 x 10(-4), 2.00 x 10(-4), 3.86 x 10(-4), 1.56 x 10(-2) mol. L(-1), respectively. Thirty-five metal salts were negative for tests performed both with and without metabolic activation, whereas it was impossible to evaluate the mutagenicity of MoCl(5) and ZrCl(4) by the umu test because of their colorimetric reaction to testing reagents. Copyright 2001 John Wiley & Sons, Inc.

Mutagenic and genotoxic activity of particulate matter MP2,5, in Pamplona, North Santander, Colombia

Directory of Open Access Journals (Sweden)

Martínez Montañez, Mónica Liseth

2012-10-01

Full Text Available Objective: To study the mutagenic and genotoxic activities of particulate material (MP2,5 collected in Pamplona, Norte de Santander, Colombia.Materials and methods: MP2,5 was monitored by means of a Partisol 2025 sequential air sampler with Plus Palmflex quartz filters. The latter were subjected to two extraction procedures: Soxhlet extraction using dichloromethane-acetone; and ultrasonic extraction using dichloromethane, acetone and dichloromethane/ acetone mix. The mutagenic and genotoxic activities were determined for each extract.Results: This is the first study conducted in Colombia that reports the mutagenic and genotoxic activities associated with particulate matter (MP2,5 taken from vehicular emissions in Pamplona, Norte de Santander. The mutagenic assay determined by the Ames test using Salmonella typhimurium strains TA98 and TA100 showed a high direct mutagenic activity in the analyzed extracts. On the other hand, the genotoxic activity, determined by means of the comet assay, was high too.Conclusion: Particulate material (MP2,5 present in air samples in Pamplona (northeastern Colombia is a risk factor for the exposed population because it can directly induce mutations and also cause genotoxic damage.

An approach to quantitate and control the mutagenic hazards of environmental chemical and radioactive pollutants

International Nuclear Information System (INIS)

Murthy, M.S.S.

1977-01-01

Human population, both at the occupational and non-occupational levels, is exposed to the environment polluted by man-made chemicals and radiation sources. The parameters required for quantitating mutagenic hazards of any agent are listed and it has been pointed out that though sufficient information of this nature is available in the case of radiations, it is almost impossible to collect similar information for chemical substances due to their number running into astronomical figures. A short-cut approach, therefore, is suggested to quantitate and control the mutagenic hazards of these pollutants. It is to express the mutagenic hazards of a chemical substance in terms of equivalent radiation units. The unit proposed for this purpose is called as Rem-Equivalent Chemical (REC). Total mutagenic burden to the society should take account of exposure from both chemicals and radiations. Advantages and limitation of this approach are discussed. (M.G.B.)

Microplate Ames MPF™ test use in assessment of mutagenic properties of dust pollution

Directory of Open Access Journals (Sweden)

Agnieszka Kozłowska

2012-09-01

Full Text Available Background: Highly industrialized Upper Silesia Region is particularly polluted by both anthropogenic and natural airborne particulate matters, which may lead to negative health effects in human. Materials and methods: The aim of the study was to assess the mutagenic properties of dust extracts which were collected in six cities in the Silesian Voivodeship. Dust samples were collected on glass fiber filters by the aspirator with air flow ca. 1 m3/min. Extraction of pollution was carried out using dichlorometane. The extracted samples were dissolved in dimethylsulfoxide (DMSO. The mutagenic properties were assessed using microplate Ames assay MPFTM with the use of bacteria Salmonella typhimurium strain TA98 and TA100. Results: In microplate Ames assay MPFTM there was observed a linear dose-response relationship in both metabolic variants of TA98 strain. Similar relationship was observed for TA100 strain with metabolic activation (S9. Mutagenic activity (AM of 100% extracts for TA98 strain in both metabolic variants (S9 exceeded 2, what indicate highly mutagenic effects of dust extracts. There was no mutagenic activity observed in the assay with TA100 (S9, AM 1. In the variant with exogenous metabolic activation (S9 in TA100 strain AM values ranged from AM1,160,15 to AM9,671,02. Mutagenic activity varied between different cities. Conclusions: The study demonstrated that microplate Ames assay MPFTM is fast and complex method of assessing the mutagenic properties of dust pollution, which exert toxic effect on organisms. The use of microplate Ames assay MPFTM together with chemical analyses of air dust pollution may evaluate the level of exposure in the environment and enable to perform health risk assessment in populations exposed to mutagenic, toxic and cytotoxic substances.

Mixed chemical-induced oxidative stress in occupational exposure ...

African Journals Online (AJOL)

Mixed chemical-induced oxidative stress in occupational exposure in Nigerians. JI Anetor, SA Yaqub, GO Anetor, AC Nsonwu, FAA Adeniyi, S Fukushima. Abstract. Exposure to single chemicals and associated disorders in occupational environments has received significant attention. Understanding these events holds ...

A methodology for assessing the impact of mutagens on aquatic ecosystems. Final report

International Nuclear Information System (INIS)

Knezovich, J.P.; Martinelli, R.E.

1995-03-01

Assessments of impacts of hazardous agents (i.e., chemical and physical mutagens) on human health have focused on defining the effects of chronic exposure on individuals, with cancer being the main effect of concern. In contrast, impacts on ecosystems have traditionally been gauged by the assessment of near-term organism mortality, which is clearly not a useful endpoint for assessing the long-term effects of chronic exposures. Impacts on individual organisms that affect the long-term survival of populations are much more important but are also more difficult to define. Therefore, methods that provide accurate measures of sub-lethal effects that are linked to population survival are required so that accurate assessments of environmental damage can be made and remediation efforts, if required, can be initiated. Radioactive substances have entered aquatic environments as a result of research and production activities, intentional disposal, and accidental discharges. At several DOE sites, surface waters and sediments are contaminated with radioactive and mutagenic materials. The accident at the Chernobyl power station in the former Soviet Union (FSU) has resulted in the contamination of biota present in the Kiev Reservoir. This documents presents a methodology which addresses the effects of a direct-acting mutagen (radiation) on aquantic organisms by applying sensitive techniques for assessing damage to genetic material

Investigations on potential co-mutagenic effects of formaldehyde

Energy Technology Data Exchange (ETDEWEB)

Speit, Günter, E-mail: guenter.speit@uni-ulm.de; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

2014-02-15

Highlights: • A549 cells were exposed to formaldehyde in combination with various mutagens. • Formaldehyde did not affect the induction and removal of DNA damage (comet assay). • Formaldehyde did not affect the induction of micronuclei by the mutagens tested. • The expression of the O{sup 6}-methylguanine-DNA methyltransferase was not affected. - Abstract: The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10–75 μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O{sup 6}-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

The photo-oxidation of automobile emissions: measurements of the transformation products and their mutagenic activity

Science.gov (United States)

Kleindienst, Tadeusz E.; Smith, David F.; Hudgens, Edward E.; Snow, Richard F.; Perry, Erica; Claxton, Larry D.; Bufalini, Joseph J.; Black, Francis M.; Cupitt, Larry T.

Dilute mixtures of automobile emissions (comprising 50% exhaust and 50% surrogate evaporative emissions) were irradiated in a 22.7 m 3 smog chamber and tested for mutagenic activity by using a variant of the Ames test. The exhaust was taken from a single vehicle, a 1977 Ford Mustang equipped with a catalytic converter. Irradiated and nonirradiated gas-phase emissions were used in exposures of the bacteria, Salmonella typhimurium, strains TA100 and TA98. A single set of vehicular operating conditions was used to perform multiple exposures. The mutagenic activities of extracts from the particulate phase were also measured with the standard plate incorporation assay. (In most experiments only direct-acting mutagenic compounds were measured.) The gas-phase data for TA100 and TA98 showed increased activity for the irradiated emissions when compared to the nonirradiated mixture, which exhibited negligible activity with respect to the control values. The particulate phase for both the irradiated and nonirradiated mixtures showed negligible activity when results were compared to the control values for both strains. However, the experimental conditions limited the amount of extractable mass which could be collected in the particulate phase. The measured activities from the gas phase and particulate phase were converted to the number of revertants per cubic meter of effluent (i.e. the mutagenic density) to compare the contributions of each of these phases to the total mutagenic activity for each strain. Under the experimental conditions of this study, the mutagenic density of the gas-phase component of the irradiated mixture contributed approximately two orders of magnitude more of the total TA100 activity than did the particulate phase. For TA98 the gas-phase component contributed approximately one order of magnitude more. However, caution must be exercised in extrapolating these results to urban atmospheres heavily impacted by automotive emissions, because the bacterial

Combined anaerobic–ozonation process for treatment of textile wastewater: Removal of acute toxicity and mutagenicity

Energy Technology Data Exchange (ETDEWEB)

Punzi, Marisa, E-mail: marisa.punzi@biotek.lu.se [Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Nilsson, Filip [Water and Environmental Engineering at the Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Anbalagan, Anbarasan [Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Svensson, Britt-Marie [School of Education and Environment, Kristianstad University, SE-291 88 Kristianstad (Sweden); Jönsson, Karin [Water and Environmental Engineering at the Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden); Mattiasson, Bo; Jonstrup, Maria [Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund (Sweden)

2015-07-15

Highlights: • COD and UV absorbance were effectively reduced. • The treated effluents were non-toxic to Artemia salina and Vibrio fischeri. • The real textile wastewater was mutagenic. • Mutagenicity persisted after bio treatment and even more after a short ozonation. • Higher ozone doses completely remove mutagenicity. - Abstract: A novel set up composed of an anaerobic biofilm reactor followed by ozonation was used for treatment of artificial and real textile effluents containing azo dyes. The biological treatment efficiently removed chemical oxygen demand and color. Ozonation further reduced the organic content of the effluents and was very important for the degradation of aromatic compounds, as shown by the reduction of UV absorbance. The acute toxicity toward Vibrio fischeri and the shrimp Artemia salina increased after the biological treatment. No toxicity was detected after ozonation with the exception of the synthetic effluent containing the highest concentration, 1 g/l, of the azo dye Remazol Red. Both untreated and biologically treated textile effluents were found to have mutagenic effects. The mutagenicity increased even further after 1 min of ozonation. No mutagenicity was however detected in the effluents subjected to longer exposure to ozone. The results of this study suggest that the use of ozonation as short post-treatment after a biological process can be beneficial for the degradation of recalcitrant compounds and the removal of toxicity of textile wastewater. However, monitoring of toxicity and especially mutagenicity is crucial and should always be used to assess the success of a treatment strategy.

Chemistry of mutagens and carcinogens in broiled food.

Science.gov (United States)

Nishimura, S

1986-01-01

From a chemical point of view, the following subjects are important areas in studies on mutagens and carcinogens in broiled foods. In addition to heterocyclic amines which need microsomal activation, the structural elucidation of more labile direct-acting mutagens is necessary. It is known that there are still various unknown minor mutagens in broiled foods. Although the structural characterization of such compounds is more difficult, it is important since they might be hazardous in spite of their low mutagenicity. A more feasible and easier method for quantitative analysis of mutagens, in addition to HPLC and GC/MS methods presently employed, must be developed. The mechanism of formation of mutagens by broiling of food should be studied. An effective chemical method to prevent formation of mutagens or to destroy them, once formed, should be developed. PMID:3757944

Relationship between DNA replication and DNA repair in human lymphocytes proliferating in vitro in the presence and in absence of mutagen

International Nuclear Information System (INIS)

Szyfter, K.; Wielgosz, M.Sz.; Kujawski, M.; Jaloszynski, P.; Zajaczek, S.

1995-01-01

The effects of mutagens on DNA replication and DNA repair were studied in peripheral blood lymphocytes (PBL) obtained from 21 healthy subjects, 2 samples from healthy heterozygote of ''Xeroderma pigmentosum'' (XP) and 2 samples from patient with clinically recognised XP. Inter-individual variations were found in DNA replication and in the level of spontaneous DNA repair measured under standard culture condition. Exposure of human PBL proliferating in vitro to B(a)P was followed by a partial inhibition of replicative DNA synthesis in all subjects and by an induction of DNA repair in healthy subjects. In XP patients DNA repair synthesis remained at the level attributed to spontaneous DNA repair. The response to mutagen varied individually. Results were analysed statistically. It was established that the studied indices of DNA synthesis correlate well with each other. The highest correlation was found between the levels of spontaneous and B(a)P-induced DNA repair. It is concluded that the level of spontaneous DNA repair is predictive for an estimation of cells ability to repair DNA damage. Inter-individual variations in the inhibition of DNA replication and in DNA repair synthesis are also dependent on the type of mutagen as shown by effects of other mutagens. Different effects of mutagen exposure on the inhibition of DNA replicative synthesis and induction of DNA repair can be explained by genetically controlled differences in the activity of enzymes responsible for mutagen processing and lesion removal. (author). 37 refs, 2 figs, 2 tabs

Human somatic, germinal and heritable mutagenicity

International Nuclear Information System (INIS)

Mendelsohn, M.L.

1987-05-01

This report deals with the general process of variant formation rather than with the consequences of a specific variant being present. It focusses on mutational mechanisms, mutagens, and the method for detecting de novo mutants and estimating mutation rate. It is to human genetics much like disease causation and prevention medicine are to medicine as a whole. The word ''mutagenicity'' is used in the title and throughout the text to connote the causation of all classes of genetic damage. Mutagenicity and the corresponding words mutation, mutagen and mutagenesis can have multiple meaning, sometimes relating to gene mutation, sometimes to heritable mutation, and somtimes to all types of genetic damage. 38 refs., 1 tab

Study of anti mutagenic and mutagenic effect of different chemicals on clinically isolated strains of pseudomonas aeruginosa

International Nuclear Information System (INIS)

Qureshi, A.M.; Durrani, F.; Janjua, M.

1994-01-01

This project was undertaken to study the effect of twelve different compounds to test their anti mutagenic and mutagenic activity against clinically isolated strains of Pseudomonas aeruginosa. The effect of these compounds was estimated by counting the number of rifampicin resistant colonies growing in a particular time in a compound. The results were interpreted by plotting graphs between 10g N/NO (Rif R Colonies/ ml) and time to estimate the forward mutation rat. The results revealed that acridine, Basic fuchsin, Caffeine, cycloheximide, Ethidium bromide and Histidine probably have an anti mutagenic effect, while Cysteine, folic acid, Ethyl methane, suplphonate, Manganous Chloride and N-nitrosodietylamine acted as mutagen. Ecoli was used as control through out the study. (author)

The mutagenic potential of high flash aromatic naphtha.

Science.gov (United States)

Schreiner, C A; Edwards, D A; McKee, R H; Swanson, M; Wong, Z A; Schmitt, S; Beatty, P

1989-06-01

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--high-flash aromatic naphtha. A program was initiated to assess the toxicological properties of high-flash aromatic naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted partly to assess the potential for mutagenic activity and also to assist in an assessment of carcinogenic potential. The specific tests utilized included the Salmonella/mammalian microsome mutagenicity assay, the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) forward mutation assay in CHO cells, in vitro chromosome aberration and sister chromatid exchange (SCE) assays in CHO cells, and an in vivo chromosome aberration assay in rat bone marrow.

Reparation in unicellular green algae during chronic exposure to the action of mutagenic factors. II. Restoration of single-stranded DNA breaks following exposure of Chlamydomonas reinchardii to gamma-irradiation

International Nuclear Information System (INIS)

Sergeeva, S.A.; Ptitsina, S.N.; Shevchenko, V.A.

1986-01-01

The restoration of single-stranded breaks in the DNA in different strains of unicellular green algae (chlamydomonads) during chronic exposure to the action of mutagenic factors following γ-irradiation was investigated. It was shown that the restoration of DNA breaks was most effective in the case of strain M γ/sup mt + /, which is resistant to radiation. Strains, that were sensitive to UV irradiation showed a similar order of DNA break restoration as the wild-type strain. Strain UVS-1 showed a higher level of restoration than the wild-type strain. The data indicated that chlamydomonads have different pathways of reparation, which lead to the restoration of breaks induced by γ-irradiation and UV-rays

Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

Energy Technology Data Exchange (ETDEWEB)

Dmochowska, Barbara [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Piosik, Jacek; Woziwodzka, Anna [Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822 Gdansk (Poland); Sikora, Karol; Wisniewski, Andrzej [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Wegrzyn, Grzegorz, E-mail: wegrzyn@biotech.univ.gda.pl [Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk (Poland)

2011-10-15

Highlights: {yields} A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. {yields} The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. {yields} The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. {yields} We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

International Nuclear Information System (INIS)

Dmochowska, Barbara; Piosik, Jacek; Woziwodzka, Anna; Sikora, Karol; Wisniewski, Andrzej; Wegrzyn, Grzegorz

2011-01-01

Highlights: → A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. → The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. → The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. → We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

Differential responses of nascent DNA synthesis and chain elongation in V79 and V79/79 cells exposed to U.V. light and chemical mutagens

International Nuclear Information System (INIS)

Fox, M.; Bloomfield, M.E.; Hopkins, J.; Boyle, J.M.

1983-01-01

DNA repair after u.v., N-methyl-N-nitrosourea (MNU) and ethylmethane sulphonate (EMS) in Chinese hamster V79 cells and the mutagen sensitive derivative V79/79 was investigated by measurement of five parameters: production of strand breaks in template DNA, incorporation of [ 3 H]TdR, semi-conservative and repair synthesis, molecular weights of pulse labelled DNA after mutagen exposure (nascent synthesis) and molecular weights of DNA pulse labelled and chased after mutagen exposure (elongation and ligation). Equal template strand breakage was evident in both cell lines immediately after MNU and EMS exposure and by 4-5 h after MNU the extent of fragmentation was greater in V79/79 cells. After u.v. irradiation template fragmentation was evident in V79/79 but not in V79 cells, even though V79/79 cells failed to excise cyclobutane dimers and repair synthesis was demonstrable in V79 cells but not in V79/79 cells after exposure to all three mutagens. The rate of incorporation of [ 3 H]TdR during semi-conservative DNA synthesis was inhibited equally in a dose dependent manner after u.v. and MNU exposure; incorporation by V79/79 cells was inhibited to a greater extent than by V79 cells after EMS exposure. Nascent DNA synthesis was suppressed more in V79/79 cells than in V79 cells after u.v. but to similar extents in both cell lines after MNU and EMS treatment. Pulse chase experiments indicated a lower rate of elongation of nascent DNA in V79/79 cells after MNU and u.v. exposure but little difference was detectable after EMS

Past, present, and future of mutagens in cooked foods.

Science.gov (United States)

Sugimura, T

1986-08-01

Mutation assay with Salmonella typhimurium enabled us to detect various types of mutagens in cooked foods. A series of mutagenic heterocyclic amines has been isolated and identified in broiled fish and meat and in pyrolyzates of amino acids and proteins. Feeding experiments showed these mutagens to be carcinogenic in mice and rats. The mechanism of formation and pathway of metabolic activation of these heterocyclic amines have been elucidated. Their contents in various cooked foods have been determined. The presence of mutagenic nitropyrenes (some of which were confirmed as carcinogens) in grilled chicken was also established. Roasted coffee beans also yield mutagens such as methylglyoxal. The formation of mutagen precursors, including beta-carboline derivatives and tyramine which become mutagens with nitrite treatment, was found during food processing. Oncogene activation in animal tumors induced by some of these food mutagens/carcinogens has been confirmed. The role of mutagens/carcinogens in cooked foods in human cancer development has not yet been exactly evaluated. In order to do this, more information on their carcinogenic potency, human intake, metabolism in the human body, and the effects of combined administration with other initiators, promoters and other modifying factors in food is required.

Mutagenic azide metabolite is azidoalanine

International Nuclear Information System (INIS)

Owais, W.M.; Rosichan, J.L.; Ronald, R.C.; Kleinhofs, A.; Nilan, R.A.

1981-01-01

Sodium axide produces high mutation rates in a number of species. Azide mutagenicity is mediated through a metabolite in barley and bacteria. Many studies showed that azide affects the L-cysteine biosynthesis pathway. Cell-free extracts of Salmonella typhimurium convert azide and O-acetylserine to the mutagenic metabolite. O-acetylserine sulfhydrylase was identified as the enzyme responsible for the metabolite biosynthesis. To confirm the conclusion that the azide metabolite is formed through the β-substitution pathway of L-cysteine, we radioactively labeled the azide metabolite using 14 C-labeled precursors. Moreover, the mutagenic azide metabolite was purified and identified as azidoalanine based on mass spectroscopy and elemental analysis. 26 refs., 3 figs., 1 tab

Mutagenic and antimutagenic activity of food compounds : Application of a dynamic in vitro gastrointestinal model

NARCIS (Netherlands)

Krul, Cyrille Anna Maria

2001-01-01

Exposure of humans to potential mutagenic and carcinogenic food compounds through the diet is unavoidable. On the other hand, there is epidemiological evidence for antimutagenic and anticarcinogenic properties of food as well (such as vegetables and fruit). The assessment of carcinogenic and cancer

A comprehensive survey of the mutagenic impact of common cancer cytotoxics

DEFF Research Database (Denmark)

Szikriszt, Bernadett; Poti, Adam; Pipek, Orsolya

2016-01-01

system, is well suited to accurately assay genomic mutations. Results: We use whole genome sequencing of multiple DT40 clones to determine the mutagenic effect of eight common cytotoxics used for the treatment of millions of patients worldwide. We determine the spontaneous mutagenesis rate at 2.3 x 10......-10 per base per cell division and find that cisplatin, cyclophosphamide and etoposide induce extra base substitutions with distinct spectra. After four cycles of exposure, cisplatin induces 0.8 mutations per Mb, equivalent to the median mutational burden in common leukaemias. Cisplatin-induced mutations......, hydroxyurea, doxorubicin and paclitaxel have no measurable mutagenic effect. The cisplatin-induced mutation spectrum shows good correlation with cancer mutation signatures attributed to smoking and other sources of guanine-directed base damage. Conclusion: This study provides support for the use of cell line...

Toxicity and mutagenicity of low-metallic automotive brake pad materials.

Science.gov (United States)

Malachova, Katerina; Kukutschova, Jana; Rybkova, Zuzana; Sezimova, Hana; Placha, Daniela; Cabanova, Kristina; Filip, Peter

2016-09-01

Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro. Copyright © 2016 Elsevier Inc. All rights reserved.

Mutagenicity potential of commercial broth cubes at varying concentrations

International Nuclear Information System (INIS)

De Torres, Nelson Velasquez; Talain, Augusto Nicolas.

1997-01-01

Today, there has been a growing concern on the mutagenicity potential of environmental chemical systems. These environmental chemicals such as pesticides, food additives, synthetic drugs, water and atmospheric pollutants are possible causes of mutagenic activity. Meat products and some meat flavorings, were also reported to exhibit mutagenic activity. And since these products are normal part of the daily human diet, there is a need for extensive studies regarding the possible mutagenic activity associated with these products. This study aimed to evaluate the mutagenicity potential of commercial broth cubes at varying concentration. The researchers sought to answer the following questions: 1. Do beef, pork and chicken broth cubes exhibit mutagenic activity? 2. Are there significant differences in the mutagenic activity among the three samples? 3. Are these significant differences in the mutagenic activity exhibited by each of the samples compared to that of Mitomycin-C (positive control)? 4. Which of the sample of each specific concentration exhibit the greatest mutagenic activity? Three specific concentrations of beef, pork and chicken broth cubes were prepared and their mutagenicity potential was evaluated by using the Micronucleus test. The formation of micro nucleated polychromatic and micro nucleated normo chromatic erythrocytes in bone marrow cells of mice treated with these samples were detected using a Carl-Zeiss photo microscope. The statistical tool used to test the validity of the null hypothesis was analysis of variance using randomized complete block design and independent T- test. (author)

Mutagenicity potential of commercial broth cubes at varying concentrations

Energy Technology Data Exchange (ETDEWEB)

De Torres, Nelson Velasquez; Talain, Augusto Nicolas

1998-12-31

Today, there has been a growing concern on the mutagenicity potential of environmental chemical systems. These environmental chemicals such as pesticides, food additives, synthetic drugs, water and atmospheric pollutants are possible causes of mutagenic activity. Meat products and some meat flavorings, were also reported to exhibit mutagenic activity. And since these products are normal part of the daily human diet, there is a need for extensive studies regarding the possible mutagenic activity associated with these products. This study aimed to evaluate the mutagenicity potential of commercial broth cubes at varying concentration. The researchers sought to answer the following questions: 1. Do beef, pork and chicken broth cubes exhibit mutagenic activity? 2. Are there significant differences in the mutagenic activity among the three samples? 3. Are these significant differences in the mutagenic activity exhibited by each of the samples compared to that of Mitomycin-C (positive control)? 4. Which of the sample of each specific concentration exhibit the greatest mutagenic activity? Three specific concentrations of beef, pork and chicken broth cubes were prepared and their mutagenicity potential was evaluated by using the Micronucleus test. The formation of micro nucleated polychromatic and micro nucleated normo chromatic erythrocytes in bone marrow cells of mice treated with these samples were detected using a Carl-Zeiss photo microscope. The statistical tool used to test the validity of the null hypothesis was analysis of variance using randomized complete block design and independent T- test. (author). 28 refs., 9 figs., 26 tabs.

Molecular and genetic mechanisms of environmental mutagens

International Nuclear Information System (INIS)

Kubitschek, H.E.; Derstine, P.L.; Griego, V.M.; Matsushita, T.; Peak, J.G.; Peak, M.J.; Reynolds, P.R.; Webb, R.B.; Williams-Hill, D.

1981-01-01

This program is primarily concerned with elucidation of the nature of DNA lesions produced by environmental and energy related mutagens, their mechanisms of action, and their repair. The main focus is on actions of chemical mutagens and electromagnetic radiations. Synergistic interactions between mutagens and the mutational processes that lead to synergism are being investigated. Mutagens are chosen for study on the basis of their potential for analysis of mutation (as genetic probes), for development of procedures for reducing mutational damage, for their potential importance to risk assessment, and for development of improved mutagen testing systems. Bacterial cells are used because of the rapidity and clarity of scientific results that can be obtained, the detailed genetic maps, and the many well-defined mutand strains available. The conventional tools of microbial and molecular genetics are used, along with intercomparison of genetically related strains. Advantage is taken of tcollective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

Cytological studies of sterility in male progeny of mutagen-exposed male parents

International Nuclear Information System (INIS)

Cacheiro, N.L.A.; Cornett, C.V.

1987-01-01

Genetic male sterility results primarily from certain types of balanced reciprocal translocations, and, more rarely, from certain numerical sex-chromosome anomalies. Sterile male offspring sired following exposure of male meiotic or postmeiotic stages to radiation or chemical mutagens are not uncommon and are predominantly carriers of balanced translocations. The chromosome breakpoints of these translocations are generally located near the ends of autosomes or anywhere in the sex chromosomes. Sterile offspring from mutagen-treated spermatogonial stem cells, on the other hand, are not only rare but most of them have no readily detectable chromosomal anomalies. Those that have are either carriers of balanced translocations, or are sex-chromosome trisomics or mosaics (XYY, XXY, XY//XYY, XO//XY, etc.). The nature of the exchange in spermatogonia-derived sterile translocations is not clear and awaits detailed study. In addition, the data base is not yet sufficient for determining the role of induced nondisjunction in the production of genetic male sterility. Accordingly, they have an ongoing project that attempts to study associations between the nature of genetic fertility impairments and the detailed chromosomal genotype, and between chromosomal causes of sterility and the nature of mutagenic treatments that produce them

Health effects of exposure to diesel exhaust particles.

Science.gov (United States)

McClellan, R O

1987-01-01

Diesel-powered vehicles emit substantially more particles than do gasoline-powered vehicles with contemporary emission control systems. The DEP are submicron in size and readily inhaled. Approximately one-fourth of the particle mass inhaled by people is deposited in the pulmonary region, some of which is retained with a half-life of several hundred days. In animal studies, exposure to high levels of DEP overwhelms the normal clearance mechanisms and results in lung burdens of DEP that exceed those predicted from observations at lower exposure concentrations. A variable amount of the mass of DEP is extractable with strong organic solvents. The extracted material contains more than a thousand individual compounds and is mutagenic in a number of bacterial and mammalian cell assays. Bioassay-directed chemical analysis of DEP had identified several hundred compounds. Many are PAHs, some of which are considered to have human carcinogenic potential. A number of nitrated compounds have been identified that account for a significant portion of the mutagenicity assayed in bacteria. The mutagenicity of the DEPE is generally reduced by addition of an S-9 cellular fraction or of serum proteins. Macrophages rapidly reduce the recoverable mutagenic activity associated with DEP. These findings support a hypothesis that detoxification of DEP-associated organics occurs rapidly in vivo. The association of benzo(a)pyrene and nitropyrene with DEP prolongs their retention in the lungs. This increased retention suggests the need to clarify the relative importance of competing mechanisms that detoxify particle-associated compounds and those that serve to enhance the retention of toxicologically important compounds. Some extracts of DEP evoke tumorigenic responses in skin-tumor bioassays, suggesting their carcinogenic potential in mammals. A number of large-scale studies have been conducted with laboratory rodents to evaluate the effects of chronic inhalation exposure to DE. An increased

Long-range transport of mutagens and other air pollutants from mainland East Asia to western Japan.

Science.gov (United States)

Coulibaly, Souleymane; Minami, Hiroki; Abe, Maho; Hasei, Tomohiro; Oro, Tadashi; Funasaka, Kunihiro; Asakawa, Daichi; Watanabe, Masanari; Honda, Naoko; Wakabayashi, Keiji; Watanabe, Tetsushi

2015-01-01

Asian dust events, transport of dust particles from arid and semi-arid areas in China and Mongolia to the east by prevailing westerlies, are often observed in Japan in spring. In recent decades, consumption of fossil fuels has markedly increased in mainland East Asia with rapid economic growth, and severe air pollution has occurred. A part of air pollutants including mutagens, such as polycyclic aromatic hydrocarbons (PAHs), generated in mainland East Asia are thought to be transported to Japan by the prevailing westerlies, like Asian dust, and winter monsoon. The objective of this study was to clarify the long-range transport of mutagens and other air pollutants in East Asia. Thus, we collected total suspended particles (TSP) at a rural town in western Japan, namely, Yurihama in Tottori Prefecture, for 1 year (June 2012-May 2013), and investigated their chemical constituents and mutagenicity. Many TSP collected from January to March showed high mutagenicity toward Salmonella typhimurium YG1024 with and without S9 mix, and high levels of lead (Pb) and sulfate ions (SO4 (2-)), which are indicators of transboundary air pollutions from mainland East Asia, were detected in those TSP. A large amount of iron, which is an indicator of sand, was found in highly mutagenic TSP collected in March, but not in TSP collected in January and February. High levels of PAHs were detected in highly mutagenic TSP collected from January to March. The ratios of the concentration of fluoranthene to those of fluoranthene and pyrene suggested that the main source of PAHs in TSP collected in winter and spring was coal and biomass combustion. Backward trajectories of air masses on days when high levels of mutagenicity were found indicated that these air masses had traveled from eastern or northern China to Yurihama. These results suggest that high levels of mutagens were transported from mainland East Asia to western Japan, and this transportation accompanied Asian dust in March, but not in

Application of the salmonella mutagenicity assay and determination of polycyclic aromatic hydrocarbons in workplaces exposed to petroleum pitch and petroleum coke

Energy Technology Data Exchange (ETDEWEB)

Monarca, S; Pasquini, R; Sforzolini, G S; Fagioli, F; Viola, V

1982-02-01

Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests were performed on pitch and coke and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity (benzene, chloroform, methanol and acetone). The results showed: (a) the presence of extraordinarily high PAH (carcinogenic and noncarcinogenic) contents in the benzene extracts of petroleum pitch (3.6 wt% of total PAH) and of airborne particulate samples (up to 0.35 wt% of total PAH), in correlation with very high indirect mutagenic responses of benzene extracts; (b) very high indirect mutagenic responses in the other extracts of the airborne particulate samples; (c) the production during the processing at high temperatures of directly acting mutagens which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.

Exposure to selected fragrance materials. A case study of fragrance-mix-positive eczema patients

DEFF Research Database (Denmark)

Johansen, J D; Rastogi, Suresh Chandra; Menné, T

1996-01-01

. In all cases, the use of these cosmetics completely or partly explained present or past episodes of eczema. Between 1 to 6 constituents of the fragrance mix were found in 22 out of 23 products. The cosmetics of all the patients sensitive to hydroxycitronellal, eugenol, cinnamic alcohol and alpha......The aim of the present study was to assess exposure to constituents of the fragrance mix from cosmetic products used by fragrance-mix-positive eczema patients. 23 products, which had either given a positive patch and/or use test in a total of 11 fragrance-mix-positive patients, were analyzed....... It is concluded that exposure to constituents of the fragrance mix is common in fragrance-allergic patients with cosmetic eczema, and that the fragrance mix is a good reflection of actual exposure....

Physicochemical characteristics, mutagenicity and genotoxicity of airborne particles under industrial and rural influences in Northern Lebanon.

Science.gov (United States)

Melki, Pamela N; Ledoux, Frédéric; Aouad, Samer; Billet, Sylvain; El Khoury, Bilal; Landkocz, Yann; Abdel-Massih, Roula M; Courcot, Dominique

2017-08-01

In this work, the main objectives were to assess the mutagenic and genotoxic effects of fine particulate matter collected in an industrial influenced site in comparison with a non-industrial influenced one (rural site) and to relate the particulate matter (PM) composition to the observed genotoxic effects. At the industrial influenced site, higher concentrations of phosphates, trace metals, and polycyclic aromatic hydrocarbons (PAHs) in particles could be related to the contributions of quarries, fertilizer producer, cement plants, and tires burning. Gasoline and diesel combustion contributions were evidenced in particles collected at both sites. Particles collected under industrial influence showed a higher mutagenic potential on three tested strains of Salmonella typhimurium (TA98, YG1041, and TA102), and especially on the YG1041, compared to particles from the rural site. Furthermore, only particles collected in the vicinity of the industrial site showed a tendency to activate the SOS responses in Escherichia coli PQ37, which is indicative of DNA damage as a result of exposure of the bacteria cells to the action of mutagenic samples. The mutagenicity and genotoxicity of the industrial PM 2.5-0.3 particulates may be attributed to its composition especially in organic compounds. This study showed that proximity of industries can affect local PM composition as well as PM genotoxic and mutagenic potential.

Application of the Salmonella mutagenicity assay and determination of polycyclic aromatic hydrocarbons in workplaces exposed to petroleum pitch and petroleum coke

Energy Technology Data Exchange (ETDEWEB)

Monarca, S; Pasquini, R; Sforzolini, G S; Viola, V; Fagioli, F

1982-02-01

Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests were performed on both industrial ingredients and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity. The results showed: the presence of extraordinarily high PAH contents in the benzene extracts of petroleum pitch and of airborne particulate samples, in correlation with very high indirect (after metabolic activation) mutagenic responses of benzene extracts with strain TA98; very high indirect mutagenic responses in the other extracts of the airborne particulate samples; the production during the processing at high temperatures of directly acting mutaggens which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.

Mutagenicity screening: General principles and minimal criteria. Report of a committee of the European Environmental Mutagen Society

NARCIS (Netherlands)

Kilbey, B.J.; Igali, S.; Lohman, P.H.M.

1978-01-01

A statement of general principles and minimal criteria for the screening of chemicals for potential mutagenicity in man that may be used as guidelines for regulatory agencies and industrial organisations. To make clear the potentialities and current limitations of short-term mutagenicity testing for

Handbook of mutagenicity test procedures

International Nuclear Information System (INIS)

Kilbey, B.J.; Legatov, M.

1977-01-01

27 articles are presented on particular techniques of mutagen testing. Background information is given in materials, experimental design, pitfalls and difficults, to enable the reader to perform these tests with minimal additional help. Also included is the use of data from population records, the handling and safety aspects of mutagens and carcinogens and some of the basic statistical concepts to be borne in mind when mutation experiments are designed. (C.F.)

Mutagenic action of non-ionizing radiations: its implication in radiation protection

International Nuclear Information System (INIS)

Madhvanath, U.; Subrahmanyam, P.; Sankaranarayanan, N.; Singh, D.R.

1977-01-01

Mutagenic effects of non-ionizing radiations except in the ultraviolet and near ultraviolet region are just not known. Results of the investigation carried out using a sensitive diploid yeast system, are presented. The arginine requiring mutant yeast strain BZ34 reverts to prototrophy following exposure to ionizing radiation. Reversion frequencies were determined following exposure to UV (254 nm), near ultraviolet (313, 353 nm) visible region (480 nm), neodymium laser (1.01 μm) and microwave (2450 MHz) radiations. An Aminco - Bowman Spectrophotofluorimeter was used to obtain wavelengths from UV to visible region. Yeast suspensions (concentration of 10 7 cells/ml) were irradiated to doses ranging from 10 7 to 10 9 erg/cm 3 as determined with potassium ferri-oxalate system. Exposure to laser pulses and microwave radiation ranged up to 45 J/cm 2 and 60 mW-h/cm 2 respectively. Results showed that the reversion induction efficiency decreased by six orders of magnitude from ionizing radiations to ultraviolet for the same absorbed dose and this efficiency has further decreased by a factor of fifteen when the wavelength is increased from 254 nm to 313 nm. Although killing could be effected with laser beams (45 J/cm 2 for 50% survival) no increase in the reversion was observed than the background level. It is concluded that radiation of wavelengths higher than 450 nm up to 12 cm studied is not mutagenic and with sufficient intensities of these radiations only killing of cells is possible due to thermal effects. This finding is compared with other known functional and morphological effects at cellular level due to low-level exposures of non-ionizing radiations

Assessment of anti-mutagenic effects of stobadine dihydro-chloride on MNNG-induced mutations in Chinese hamster cells V79

International Nuclear Information System (INIS)

Horvathova, E.; Slamenova, D.; Chorvatovicova, D.; Wsolova, L.

1995-01-01

Mutagenicity of N-methyl-n'-nitro-N-nitrosoguanidine (MNNG) and anti-mutagenic effect of antioxidant stobadine (STB) were investigated by so called HGPRT/V79 system. Cells were treated by STB before, during and after MNNG-treatment. Our results showed that the highest anti-mutagenic effect of STB was observed if the drug was given as a pretreatment before exposure of cells to MNNG. This effect was not concentration dependent within the framework of 1.5 - 9 mmol. All other combinations of MNNG- and STB-treatment led to the weaker but statistically significant decrease of 6-TG r mutations. Inhibition of proteosynthesis induced by methylxanthine pentoxifylline in the time of pre-MNNG-treatment removed completely anti-mutagenic effects of STB. In addition of mutagenicity assays, cytotoxicity of STB and combined effects of MNNG and STB were studied. Trypan blue exclusion and growth activity of influenced cells showed that application of STB (1.5 mmol) before or after MNNG (0.5 μg/cm 3 ) treatment had a similar toxic effects as MNNG alone. Application of STB during MNNG-treatment or pretreatment of cells with STB followed by combined treatment of cells by STB + MNNG statistically significantly decreased viability of cells. There are probably no relationship between the anti-mutagenic and the toxic effects of combined influence of STB and MNNG on V79 cells. (author)

Mutagenicity studies with the mouse spot test

Energy Technology Data Exchange (ETDEWEB)

Gocke, E.; Wild, D.; Eckhardt, K.; King, M.T.

1983-04-01

The mammalian spot test, which detects somatic gene mutations in mouse embryos, was investigated with selected chemicals to (a) further validate this test system ethylnitrosourea, ethyl methanesulfonate, 2-acetylaminofluorene and colchicine (ENU, EMS, 2AAF), and (b) evaluate the mutagenic potential, in a whole-mammal system, of environmental compounds that had been previously recognized as mutagens in other mammalian or submammalian test systems (1,2-dichloroethane, hydroquinone, nitrofurantoin, o-phenylenediamine, fried sausage extract). Of these substances, ENU, EMS and 2AAF were significantly mutagenic, 1,2-dichloroethane was probably weakly mutagenic. The ENU data were used to estimate the number of pigment precursor cells present at the time of treatment (day 9.25). We also describe in this report the use of a fluorescence microscope for classification of hairs from spots on the coat of C57BL/6JHan X T hybrids.

Evaluating the mutagenic potential of aerosol organic compounds using informatics-based screening

Science.gov (United States)

Decesari, Stefano; Kovarich, Simona; Pavan, Manuela; Bassan, Arianna; Ciacci, Andrea; Topping, David

2018-02-01

Whilst general policy objectives to reduce airborne particulate matter (PM) health effects are to reduce exposure to PM as a whole, emerging evidence suggests that more detailed metrics associating impacts with different aerosol components might be needed. Since it is impossible to conduct toxicological screening on all possible molecular species expected to occur in aerosol, in this study we perform a proof-of-concept evaluation on the information retrieved from in silico toxicological predictions, in which a subset (N = 104) of secondary organic aerosol (SOA) compounds were screened for their mutagenicity potential. An extensive database search showed that experimental data are available for 13 % of the compounds, while reliable predictions were obtained for 82 %. A multivariate statistical analysis of the compounds based on their physico-chemical, structural, and mechanistic properties showed that 80 % of the compounds predicted as mutagenic were grouped into six clusters, three of which (five-membered lactones from monoterpene oxidation, oxygenated multifunctional compounds from substituted benzene oxidation, and hydroperoxides from several precursors) represent new candidate groups of compounds for future toxicological screenings. These results demonstrate that coupling model-generated compositions to in silico toxicological screening might enable more comprehensive exploration of the mutagenic potential of specific SOA components.

Mutagenicity of heated sugar-casein systems: effect of the Maillard reaction.

Science.gov (United States)

Brands, C M; Alink, G M; van Boekel, M A; Jongen, W M

2000-06-01

The formation of mutagens after the heating of sugar-casein model systems at 120 degrees C was examined by the Ames test, using Salmonella typhimurium strain TA100. Several sugars (glucose, fructose, galactose, tagatose, lactose, and lactulose) were compared in their mutagenicities. Mutagenicity could be fully ascribed to Maillard reaction products and strongly varied with the kind of sugar. The differences in mutagenicity among the sugar-casein systems were caused by a difference in reaction rate and a difference in reaction mechanism. Sugars with a comparable reaction mechanism (glucose and galactose) showed a higher mutagenic activity corresponding with a higher Maillard reactivity. Disaccharides showed no mutagenic activity (lactose) or a lower mutagenic activity (lactulose) than their corresponding monosaccharides. Ketose sugars (fructose and tagatose) showed a remarkably higher mutagenicity compared with their aldose isomers (glucose and galactose), which was due to a difference in reaction mechanism.

Cytological effects of some new mutagens on rice

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Jin Wei

2002-01-01

Air-dried seeds of five rice varieties were carried by recoverable satellite (RS) for space mutation and were irradiated by synchronous irradiation (soft X-rays), protons and nitrogen ions. The cytological effects were compared with that of γ-irradiation. The results indicated that all the mutagens were able to induce variation on chromosome structure in root tip cells. The space environment had a stimulating mitotic effect on root tip cells. Other mutagens had inhibiting mitotic actions. The rates of micronuclei induced by synchronous irradiation and other mutagens were higher than that by γ-rays; and the rates of chromosomal bridge were lower. Furthermore, the radiosensitivity of five varieties varied with different mutagens

Tissue-specific metabolic activation and mutagenicity of 3-nitrobenzanthrone in MutaMouse.

Science.gov (United States)

Chen, Guosheng; Gingerich, John; Soper, Lynda; Douglas, George R; White, Paul A

2008-10-01

3-Nitrobenzanthrone (3-NBA) is a mutagen and suspected human carcinogen detected in diesel exhaust, airborne particulate matter, and urban soil. We investigated the tissue specific mutagenicity of 3-NBA at the lacZ locus of transgenic MutaMouse following acute single dose or 28-day repeated-dose oral administration. In the acute high dose (50 mg/kg) exposure, increased lacZ mutant frequency was observed in bone marrow and colonic epithelium, but not in liver and bladder. In the repeated-dose study, a dose-dependent increase in lacZ mutant frequency was observed in bone marrow and liver (2- and 4-fold increase above control), but not in lung or intestinal epithelium. In addition, a concentration-dependent increase in mutant frequency (8.5-fold above control) was observed for MutaMouse FE1 lung epithelial cells exposed in vitro. 1-Nitropyrene reductase, 3-NBA reductase, and acetyltransferase activities were measured in a variety of MutaMouse specimens in an effort to link metabolic activation and mutagenicity. High 3-NBA nitroreductase activities were observed in lung, liver, colon and bladder, and detectable N-acetyltransferase activities were found in all tissues except bone marrow. The relatively high 3-NBA nitroreductase activity in MutaMouse tissues, as compared with those in Salmonella TA98 and TA100, suggests that 3-NBA is readily reduced and activated in vivo. High 3-NBA nitroreductase levels in liver and colon are consistent with the elevated lacZ mutant frequency values, and previously noted inductions of hepatic DNA adducts. Despite an absence of induced lacZ mutations, the highest 3-NBA reductase activity was detected in lung. Further studies are warranted, especially following inhalation or intratracheal exposures. Published 2008 Wiley-Liss, Inc.

Is Tobacco Smoke a Germ-Cell Mutagen?

Science.gov (United States)

Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

Mutagens from the cooking of food. III. Survey by Ames/Salmonella test of mutagen formation in secondary sources of cooked dietary protein

Energy Technology Data Exchange (ETDEWEB)

Bjeldanes, L F [Univ. of California, Berkeley; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-01-01

A survey of mutagen formation during the cooking of a variety of protein-rich foods that are minor sources of protein intake in the American diet is reported (see Bjeldanes, Morris, Felton et al. (1982) for survey of major protein foods). Milk, cheese, tofu and organ meats showed negligible mutagen formation except following high-temperature cooking for long periods of time. Even under the most extreme conditions, tofu, cheese and milk exhibited fewer than 500 Ames/Salmonella typhimurium revertants/100 g equivalents (wet weight of uncooked food), and organ meats only double that amount. Beans showed low mutagen formation after boiling followed by frying (with and without oil). Only boiling of beans followed by baking for 1 hr gave appreciable mutagenicity (3650 revertants/100 g equivalents). Seafood samples gave a variety of results: red snapper, salmon, trout, halibut and rock cod all gave more than 1000 revertants/100 g wet weight equivalents when pan-fried or griddle-fried for about 6 min/side. Baked or poached rock cod and deep-fried shrimp showed no significant mutagen formation. Broiled lamb chops showed mutagen formation similar to that in red meats tested in the preceding paper: 16,000 revertants/100 g equivalents. These findings show that as measured by bioassay in S. typhimurium, most of the food that are minor sources of protein in the American diet are also minor sources of cooking-induced mutagens.

Mutagens from the cooking of food. III. Survey by Ames/Salmonella test of mutagen formation in secondary sources of cooked dietary protein.

Science.gov (United States)

Bjeldanes, L F; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-08-01

A survey of mutagen formation during the cooking of a variety of protein-rich foods that are minor sources of protein intake in the American diet is reported (see Bjeldanes, Morris, Felton et al. (1982) for survey of major protein foods). Milk, cheese, tofu and organ meats showed negligible mutagen formation except following high-temperature cooking for long periods of time. Even under the most extreme conditions, tofu, cheese and milk exhibited fewer than 500 Ames/Salmonella typhimurium revertants/100 g equivalents (wet weight of uncooked food), and organ meats only double that amount. Beans showed low mutagen formation after boiling and boiling followed by frying (with and without oil). Only boiling of beans followed by baking for 1 hr gave appreciable mutagenicity (3650 revertants/100g equivalents). Seafood samples gave a variety of results: red snapper, salmon, trout, halibut and rock cod all gave more than 1000 revertants/100 g wet weight equivalents when pan-fried or griddle-fried for about 6 min/side. Baked or poached rock and deep-fried shrimp showed no significant mutagen formation. Broiled lamb chops showed mutagen formation similar to that in red meats tested in the preceding paper: 16,000 revertants/100 g equivalents. These findings show that as measured by bioassay in S. typhimurium, most of the foods that are minor sources of protein in the American diet are also minor sources of cooking-induced mutagens.

Mutagenic DNA repair in enterobacteria

International Nuclear Information System (INIS)

Sedgwick, S.G.; Chao Ho; Woodgate, R.

1991-01-01

Sixteen species of enterobacteria have been screened for mutagenic DNA repair activity. In Escherichia coli, mutagenic DNA repair is encoded by the umuDC operon. Synthesis of UmuD and UmuC proteins is induced as part of the SOS response to DNA damage, and after induction, the UmuD protein undergoes an autocatalytic cleavage to produce the carboxy-terminal UmuD' fragment needed for induced mutagenesis. The presence of a similar system in other species was examined by using a combined approach of inducible-mutagenesis assays, cross-reactivity to E. coli UmuD and UmuD' antibodies to test for induction and cleavage of UmuD-like proteins, and hybridization with E. coli and Salmonella typhimurium u mu DNA probes to map umu-like genes. The results indicate a more widespread distribution of mutagenic DNA repair in other species than was previously thought. They also show that umu loci can be more complex in other species than in E. coli. Differences in UV-induced mutability of more than 200-fold were seen between different species of enteric bacteria and even between multiple natural isolates of E. coli, and yet some of the species which display a poorly mutable phenotype still have umu-like genes and proteins. It is suggested that umuDC genes can be curtailed in their mutagenic activities but that they may still participate in some other, unknown process which provides the continued stimulus for their retention

Mutagens from the cooking of food. II. Survey by Ames/Salmonella test of mutagen formation in the major protein-rich foods of the American diet

Energy Technology Data Exchange (ETDEWEB)

Bjeldanes, L.F. (Univ. of California, Berkeley); Morris, M.M.; Felton, J.S.; Healy, S.; Stuermer, D.; Berry, P.; Timourian, H.; Hatch, F.T.

1982-01-01

The formation of mutagens in the major cooked protein-rich foods in the US diet was studied in the Ames Salmonella typhimurium test. The nine protein-rich foods most commonly eaten in the USA--ground beef, beef steak, eggs, pork chops, fried chicken, pot-roasted beef, ham, roast beef and bacon--were examined for their mutagenicity towards S. typhimurium TA1538 after normal 'household' cooking (deep frying, griddle/pan frying, baking/roasting, broiling, stewing, braising or boiling at 100-475/sup 0/C). Well-done fried ground beef, beef steak, ham, pork chops and bacon showed significant mutagen formation. For chicken and beef steak high-temperature broiling produced the most mutagenicity, followed by baking/roasting and frying. Stewing, braising and deep frying produced little mutagen. Eggs andd egg products produced mutagens only after cooking at high temperatures (the yolk to a greater extent than the white). Commercially cooked hamburgers showed a wide range of mutagenic activity. We conclude that mutagen formation following cooking of protein-containing foods is a complex function of food type, cooking time and cooking temperature. It seems clear that all the major protein-rich foods if cooked to a well-done state on the griddle (eggs only at temperature above 225/sup 0/C) or by broiling will contain mutagens detectable by the Ames/Salmonella assay. This survey is a step towards determining whether any human health hazard results from cooking protein-rich foods. Further testing in both short- and long-term genotoxicity bioassays and carcinogenesis assays are needed before any human risk extrapolations can be made.

Mutagens from the cooking of food. II. Survey by Ames/Salmonella test of mutagen formation in the major protein-rich foods of the American diet.

Science.gov (United States)

Bjeldanes, L F; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-08-01

The formation of mutagens in the major cooked protein-rich foods in the US diet was studied in the Ames Salmonella typhimurium test. The nine protein-rich foods most commonly eaten in the USA--ground beef, beef steak, eggs, pork chops, fried chicken, pot-roasted beef, ham, roast beef and bacon--were examined for their mutagenicity towards S. typhimurium TA1538 after normal 'household' cooking (deep frying, griddle/pan frying, baking/roasting, broiling, stewing, braising or boiling of 100-475 degrees C). Well-done fried ground beef, beef steak, ham pork chops and bacon showed significant mutagen formation. For chicken and beef steak high-temperature broiling produced the most mutagenicity, followed by baking/roasting and frying. Stewing, braising and deep frying produced little mutagen. Eggs and egg products produced mutagens only after cooking at high temperatures (the yolk to a greater extent than the white). Commercially cooked hamburgers showed a wide range of mutagenic activity. We conclude that mutagen formation following cooking of protein-containing foods is a complex function of food type, cooking time and cooking temperature. It seems clear that all the major protein-rich foods if cooked to a well-done state on the griddle (eggs only at temperatures above 225 degrees C) or by broiling will contain mutagens detectable by the Ames/Salmonella assay. This survey is a step towards determining whether any human health hazard results from cooking protein-rich foods. Further testing in both short- and long-term genotoxicity bioassays and carcinogenesis assays are needed before any human risk extrapolations can be made.

Application of mammalian cytogenetics to mutagenicity studies

International Nuclear Information System (INIS)

Brewen, J.G.

1977-01-01

Studies on induction of chromosome damage in germ cells by triethylene melamine (TEM) included determination of frequencies of chromosomal aberrations observed in human leukocytes after treating different stages of the cell cycle with TEM, frequencies of chromatid aberrations in metaphase I oocytes and the female pronuclear chromosomes following treatment of female mice with TEM, and frequencies of labeled diplotene-diakinesis figures and chromosome abberations at various intervals after treatment of primary spermatocytes with TEM and 3 H-thymidine. Studies on effects of low linear energy transfer radiation on mouse oocytes showed that the frequency of aberrations increased as a function of time and remained constant 8 to 9 days post-exposure. It was concluded that cytogenetic procedures were adequate to evaluate certain mutagenic end points

Effects of diet composition on mutagenic activity in urine.

Science.gov (United States)

Ohara, Akihiro; Matsuhisa, Tsugio

2004-01-01

The effects of dietary habits on mutagenic activity in urine were investigated using the umu test based on the use of the genetically engineered bacteria Salmonella typhimurium TA 1535 pSK1002. Genotoxic effects in sample urine were detected by measuring the activation of the SOS response in the bacteria and recording the beta- galactosidase activity. Human subjects consisted of smokers and non-smokers. Urine from subjects who consumed fish showed the highest mutagenic activity, followed by the urine samples from subjects who ate pork or beef. Chicken induced a low level of mutagenic activity. When the subjects ate fried or roasted animal foods, the urine samples gave higher mutagenicity than the urine samples from the subject who consumed non-fried or non-roasted animal foods. When the subject ate vegetables along with a diet rich in animal foods, the activity in urine decreased. Herbs and spices gave the same tendency toward decline as vegetables. Non-smoker urine shower mutagenic activity than samples from smokers.

Health effects of soy-biodiesel emissions: mutagenicity-emission factors.

Science.gov (United States)

Mutlu, Esra; Warren, Sarah H; Matthews, Peggy P; King, Charly; Walsh, Leon; Kligerman, Andrew D; Schmid, Judith E; Janek, Daniel; Kooter, Ingeborg M; Linak, William P; Gilmour, M Ian; DeMarini, David M

2015-01-01

Soy biodiesel is the predominant biodiesel fuel used in the USA, but only a few, frequently conflicting studies have examined the potential health effects of its emissions. We combusted petroleum diesel (B0) and fuels with increasing percentages of soy methyl esters (B20, B50 and B100) and determined the mutagenicity-emission factors expressed as revertants/megajoule of thermal energy consumed (rev/MJ(th)). We combusted each fuel in replicate in a small (4.3-kW) diesel engine without emission controls at a constant load, extracted organics from the particles with dichloromethane, determined the percentage of extractable organic material (EOM), and evaluated these extracts for mutagenicity in 16 strains/S9 combinations of Salmonella. Mutagenic potencies of the EOM did not differ significantly between replicate experiments for B0 and B100 but did for B20 and B50. B0 had the highest rev/MJ(th), and those of B20 and B100 were 50% and ∼85% lower, respectively, in strains that detect mutagenicity due to polycyclic aromatic hydrocarbons (PAHs), nitroarenes, aromatic amines or oxidative mutagens. For all strains, the rev/MJ(th) decreased with increasing biodiesel in the fuel. The emission factor for the 16 EPA Priority PAHs correlated strongly (r(2 )= 0.69) with the mutagenicity-emission factor in strain TA100 + S9, which detects PAHs. Under a constant load, soy-biodiesel emissions were 50-85% less mutagenic than those of petroleum diesel. Without additional emission controls, petroleum and biodiesel fuels had mutagenicity-emission factors between those of large utility-scale combustors (e.g. natural gas, coal, or oil) and inefficient open-burning (e.g. residential wood fireplaces).

Mutagenic effectiveness and efficiency of gamma rays and ethyl methanesulhonate in Indian mustard

International Nuclear Information System (INIS)

Prasad, Rajendra; Singh, Basudeo

1986-01-01

Mutagenic effectiveness is a measure of the frequency of mutations induced by unit dose of a mutagen while mutagenic efficiency gives the proportion of mutations in relation to other associated undesirable biological effects such as gross chromosomal aberrations, lethality and sterility induced by the mutagen in question (Konzak, et al., 1965). The usefulness of any mutagen in plant breeding depends not only on its mutagenic effectiveness but also on its mutagenic efficiency. The efficiency and effectiveness of ethyl methanesulphonate (EMS) in relation to gamma rays in Indian mustard [Brassica juncea (L.) Czern and Coss] was studied. (author)

Effects of gamma radiations with or without chemical mutagens on rose seeds

International Nuclear Information System (INIS)

Lata, P.

1988-01-01

A preliminary experiment with seeds from 4 diploids, 17 tetraploids, 2 hexaploids and 1 octoploid roses confirmed that seed collection during early autumn under climatical conditions of London, gives a high percentage of viable seeds than those collected during late autumn. Seed stratification for about 100 days enhances germination when carried out under wet, purified sand. Harmful effects of radiations were recorded on seed germination, seedling survival, growth and flowering, after 0-120 Kr exposures of gamma rays. Rose cultivars were found to be more sensitive to radiations than the Rosa spp. The LD50 for diploid R. rugosa typica was between 20-30 Kr and for allo-tetraploid cultivar Aunty Dora, it was 8 Kr. No significant effect of radiations on seedling growth was recorded. Flowering in seedlings, raised from cultivar seeds, produced flowers during the first year of germination as compared with R. spp. seedlings which flowered after 3 to 4 years of germination. Among the chemical mutagens, Hydroxylamine produced least harmful effects on seed germination and survivals than those produced by Ethyl methane sulphonate; used alone or combined with low or high doses of radiations. The average seedling heights and number of leaves per seedlings were not affected. Mutagens were responsible for bringing about a loss in colour intensity which was more frequent when radiations and mutagens were used together. Real flower colour changes were rare and were attributed to the pollinating parent or mutagen or both. Present experiments indicate that although there are initial difficulties with seed germination but the resulting seedlings with increased genetic variability can generously reward a rose breeder in introducing new roses with rare combination of desirable characters which are difficult to accomplish merely by induced somatic mutations

Assessment of predictivity of volatile organic compounds carcinogenicity and mutagenicity by freeware in silico models.

Science.gov (United States)

Guerra, Lília Ribeiro; de Souza, Alessandra Mendonça Teles; Côrtes, Juliana Alves; Lione, Viviane de Oliveira Freitas; Castro, Helena Carla; Alves, Gutemberg Gomes

2017-12-01

The application of in silico methods is increasing on toxicological risk prediction for human and environmental health. This work aimed to evaluate the performance of three in silico freeware models (OSIRIS v.2.0, LAZAR, and Toxtree) on the prediction of carcinogenicity and mutagenicity of thirty-eight volatile organic compounds (VOC) related to chemical risk assessment for occupational exposure. Theoretical data were compared with assessments available in international databases. Confusion matrices and ROC curves were used to evaluate the sensitivity, specificity, and accuracy of each model. All three models (OSIRIS, LAZAR and Toxtree) were able to identify VOC with a potential carcinogenicity or mutagenicity risk for humans, however presenting differences concerning the specificity, sensitivity, and accuracy. The best predictive performances were found for OSIRIS and LAZAR for carcinogenicity and OSIRIS for mutagenicity, as these softwares presented a combination of negative predictive power and lower risk of false positives (high specificity) for those endpoints. The heterogeneity of results found with different softwares reinforce the importance of using a combination of in silico models to occupational toxicological risk assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Pharmaceutical wastewater being composite mixture of environmental pollutants may be associated with mutagenicity and genotoxicity.

Science.gov (United States)

Sharif, Ali; Ashraf, Muhammad; Anjum, Aftab Ahmed; Javeed, Aqeel; Altaf, Imran; Akhtar, Muhammad Furqan; Abbas, Mateen; Akhtar, Bushra; Saleem, Ammara

2016-02-01

Pharmaceutical industries are amongst the foremost contributor to industrial waste. Ecological well-being is endangered owing to its facile discharge. In the present study, heavy metals and organic contaminants in waste water were characterized using atomic absorption spectrophotometer and GC-MS, respectively. Mutagenicity and genotoxic potential of pharmaceutical waste water were investigated through bacterial reverse mutation assay and in vitro comet assay, respectively. Ames test and comet assay of first sample were carried out at concentrations of 100, 50, 25, 12.5, 6.25 % v/v effluent with distilled water. Chromium (Cr), lead (Pb), arsenic (As), and cadmium (Cd) were found in high concentrations as compared to WHO- and EPA-recommended maximum limits. Arsenic was found to be the most abundant metal and its maximum concentration was 0.8 mg.L(-1). GC-MS revealed the presence of lignocaine, digitoxin, trimethoprim, caffeine, and vitamin E in waste water. Dose-dependent decrease in mutagenic index was observed in both strains. Substantial increase in mutagenicity was observed for TA-100, when assay was done by incorporating an enzyme activation system, whereas a slight increase was detected for TA-102. In vitro comet assay of waste water exhibited decrease in damage index and percentage fragmentation with the increase in dilution of waste water. Tail length also decreased with an increase in the dilution factor of waste water. These findings suggest that pharmaceutical waste water being a mix of different heavy metals and organic contaminants may have a potent mutagenic and genotoxic effect on exposed living organisms.

Predictive Models for Carcinogenicity and Mutagenicity ...

Science.gov (United States)

Mutagenicity and carcinogenicity are endpoints of major environmental and regulatory concern. These endpoints are also important targets for development of alternative methods for screening and prediction due to the large number of chemicals of potential concern and the tremendous cost (in time, money, animals) of rodent carcinogenicity bioassays. Both mutagenicity and carcinogenicity involve complex, cellular processes that are only partially understood. Advances in technologies and generation of new data will permit a much deeper understanding. In silico methods for predicting mutagenicity and rodent carcinogenicity based on chemical structural features, along with current mutagenicity and carcinogenicity data sets, have performed well for local prediction (i.e., within specific chemical classes), but are less successful for global prediction (i.e., for a broad range of chemicals). The predictivity of in silico methods can be improved by improving the quality of the data base and endpoints used for modelling. In particular, in vitro assays for clastogenicity need to be improved to reduce false positives (relative to rodent carcinogenicity) and to detect compounds that do not interact directly with DNA or have epigenetic activities. New assays emerging to complement or replace some of the standard assays include VitotoxTM, GreenScreenGC, and RadarScreen. The needs of industry and regulators to assess thousands of compounds necessitate the development of high-t

Metabolic aspects of pyrolysis mutagens in food

International Nuclear Information System (INIS)

Sato, S.; Negishi, C.; Umemoto, A.; Sugimura, T.

1986-01-01

The first step in metabolic activation of mutagenic and carcinogenic heterocyclic amines has been elucidated to be N-hydroxylation by cytochrome P-448. N-Hydroxyamino compounds are further activated to form N-O-acyl derivatives that readily react with DNA. The adducts between the metabolites of Trp-P-2 and Glu-P-1 and DNA were shown to have a C 8 -guanylamino structure. In the case of Glu-P-1, modification of guanine in GC clusters occurred preferentially. Glutathione transferases and myeloperoxidase were shown to inactivate some heterocyclic amines or their active metabolites. Hemin and fatty acids bind to and inactivate them. Fibers and other factors from vegetables also work to inactivate heterocyclic amines. Nitrite at low pH also degraded some heterocyclic amines, but those with an imidazole moiety were resistant. Glu-P-1 induced intestinal tumors in a high incidence when fed orally to rats. When 14 C-Glu-P-1 was administered by gavage into rats about 50% and 35% were excreted into feces and urine, respectively, within 24 hr. When the bile was collected, around 60% of radioactivity was excreted into it within 24 hr. In the bile, N-acetyl-Glu-P-1 was identified as one of the metabolites of Glu-P-1. It showed a mutagenic activity of about one fourth that of Glu-P-1 with S9 mix. Some radioactivity was also detected in the blood. At 24 hr after administration, most of the radioactivity was found to be bound to erythrocyte β-globins and serum proteins including albumin

Changes in mutagenicity of protein pyrolyzates by reaction with nitrite.

Science.gov (United States)

Yoshida, D; Matsumoto, T

1978-09-01

Pyrolyzates of protein and related materials were treated with nitrite under acidic conditions, and the mutagenic activity toward Salmonella tester strains was determined. After treatment with nitrite in acidic solution, casein pyrolyzate, an extract of roasted chicken meat, tobacco-smoke condensate and some aromatic amines showed appreciable decreases in their mutagenic activities toward Salmonella typhimurium TA 98. Aromatic amines in the pyrolyzates may be changed by nitrite treatment to other forms having no or lower mutagenic activity toward Salmonella typhimurium TA 98. The contribution by aromatic amines to the total mutagenic activity of the pyrolyzates was as high as 80% in both casein pyrolyzate and extract of roasted chicken meat and 50% in tobacco-smoke condensate. Pyrolyzates of protein and related materials did not show a decrease in the mutagenic activity toward Salmonella typhimurium TA 100 with the same treatment.

Mutagenic effects of β-rays on rice (oryza sativa L.)

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Shen Mei; Xu Gang

1994-07-01

The mutagenic effects of 14 C and some other mutagenic factors were compared, and the relationships between mutagenic effects of 14 C and treated stages, doses and methods were studied with different rice varieties as test materials. The mutation rates of heading date and plant height were observed in M 2 . The results showed that the mutagenic effects of 14 C were better than those of other mutagenic factors tested. It is most effective for inducing early-maturing mutation to treat plants with the doses of 333 x 10 4 Bq/plant at the stage of pollen mother cell formation; but for dwarf mutation , they were treated with 74 x 10 4 Bq/plant at the stage of pistil and stamen formation to pollen mother cell formation. As a best treating method, Na 2 14 CO 3 solution was injected to plant bases

Mutagenic activity of halogenated propanes and propenes: effect of bromine and chlorine positioning.

Science.gov (United States)

Låg, M; Omichinski, J G; Dybing, E; Nelson, S D; Søderlund, E J

1994-10-01

A series of halogenated propanes and propenes were studied for mutagenic effects in Salmonella typhimurium TA100 in the absence or presence of NADPH plus liver microsomes from phenobarbital-induced rats as an exogenous metabolism system. The cytotoxic and mutagenic effects of the halogenated propane 1,2-dibromo-3-chloropropane (DBCP) has previously been studied in our laboratories. These studies showed that metabolic activation of DBCP was required to exert its detrimental effects. All of the trihalogenated propane analogues were mutagenic when the microsomal activation system was included. The highest mutagenic activity was obtained with 1,2,3-tribromopropane, with approximately 50-fold higher activity than the least mutagenic trihalogenated propane, 1,2,3-trichloropropane. The order of mutagenicity was as follows: 1,2,3-tribromopropane > or = 1,2-dibromo- 3-chloropropane > 1,3-dibromo-2-chloropropane > or = 1,3-dichloro-2-bromopropane > 1-bromo-2,3-dichloropropane > 1,2,3-trichloropropane. Compared to DBCP, the dihalogenated propanes were substantially less mutagenic. Only 1,2-dibromopropane was mutagenic and its mutagenic potential was approximately 1/30 of that of DBCP. In contrast to DBCP, 1,2-dibromopropane showed similar mutagenic activity with and without the addition of an activation system. The halogenated propenes 2,3-dibromopropene and 2-bromo-3-chloropropene were mutagenic to the bacteria both in the absence and presence of the activation system, whereas 2,3-dichloropropene did not show any mutagenic effect. The large differences in mutagenic potential between the various halogenated propanes and propenes are proposed to be due to the formation of different possible proximate and ultimate mutagenic metabolites resulting from the microsomal metabolism of the various halogenated propanes and propenes, and to differences in the rate of formation of the metabolites. Pathways are proposed for the formation of genotoxic metabolites of di- and trihalogenated

Mutagenic activity of airborne particulate matter from the urban area of Porto Alegre, Brazil

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Vera Maria Ferrão Vargas

1998-06-01

Full Text Available The mutagenic activity of airborne particulate matter collected from three different sites within the urban area of Porto Alegre, Brazil, was investigated using a Salmonella/microsome assay. Samples were extracted by sonication, sequentially, with cyclohexane (CX, and dichloromethane (DCM, for a rough fractionation by polarity. The different fractions were tested for mutagenicity using Salmonella typhimurium strains TA98, with and without metabolic activation (S9 mix fraction, and TA98NR and TA98/1,8-DNP6, without metabolic activation. Mutagenic response was observed for frameshift strain TA98 in assays with and without metabolization for two sites (sites 2 and 3, which had considerable risk of environmental contamination by nonpolar (CX and/or moderately polar (DCM compounds. However, the values of revertants/m3 (rev/m3 were highest on the site subject to automobile exhaust (site 3 in assays without (9.56 rev/m3 and with metabolization (5.08 rev/m3. Maximum mutagenic activity was detected in the moderately polar fraction, decreasing after metabolization. Nevertheless, the nonpolar fractions (CX gave higher mutagenic activity in the presence of metabolization than in the absence of the S9 mix fraction. The responses observed for TA98NR and TA98/1,8-DNP6 strains suggest the activity of nitrocompounds.Foi investigada a atividade mutagênica de material particulado de amostras de ar coletadas em três diferentes locais dentro da área urbana da cidade de Porto Alegre, Brasil, através do ensaio Salmonella/microssoma. As amostras foram extraídas, em ultra-som, por fracionamento seqüencial de acordo com a polaridade, utilizando os solventes ciclohexano (CX e diclorometano (DCM. As diferentes frações foram testadas para mutagenicidade com as linhagens de Salmonella typhimurium TA98, em presença e ausência de ativação metabólica, e TA98NR e TA98/1,8-DNP6 em ausência de metabolização. Observou-se resposta mutagênica positiva, do tipo erro

Effect of physical and chemical mutagens on morphological parameters in garlic

International Nuclear Information System (INIS)

Choudhary, A.D.; Dnyansagar, V.R.

1980-01-01

Cloves of garlic (Allium sativum Linn.) were treated with various doses of gamma rays and different concentrations of ethylmethane sulphonate, diethyl sulphate and ethyleneimine. The effect of mutagens was studied in respect of morphological parameters such as sprouting, survival, sprout height, plant height, number and size of leaves, number of cloves and weight of bulb. In case of mutagen treatment the percentage of sprouting and survival as well as sprout height were found to be decreased with an increase in the dose/concentration of the mutagen. The effect of mutagen on leaf size and number was inhibitory. However, the number of cloves and weight of bulb were found to be increased at lower dose concentration of mutagens. (author)

Mutagenicity of heated sugar-casein systems : effect of the Maillard :reaction

NARCIS (Netherlands)

Brands, C.M.J.; Alink, G.M.; Boekel, van M.A.J.S.; Jongen, W.M.F.

2000-01-01

The formation of mutagens after the heating of sugar-casein model systems at 120 C was examined by the Ames test, using Salmonella typhimurium strain TA100. Several sugars (glucose, fructose, galactose, tagatose, lactose, and lactulose) were compared in their mutagenicities. Mutagenicity could be

Mutagenicity assessment of aerosols in emissions from wood combustion in Portugal

International Nuclear Information System (INIS)

Vu, B.; Alves, C.A.; Gonçalves, C.; Pio, C.; Gonçalves, F.; Pereira, R.

2012-01-01

Polycyclic aromatic hydrocarbon (PAH) extracts of fine particles (PM 2.5 ) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods were Pinus pinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (golden wattle), Quercus faginea (Portuguese oak), Olea europea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start conditions. A mutagenic response was recorded for all species except golden wattle, maritime pine, and briquettes. The mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. These extracts were obtained both from two burning appliances and start-up conditions. However, fireplace seemed to favour the occurrence of mutagenic emissions. The negative result recorded for golden wattle was interesting, in an ecological point of view, since after confirmation, this invasive species, can be recommended for domestic use. - Highlights: ► Both woodstove and fireplace, either with a cold or hot start, produce emissions with mutagenic potential. ► The high level of carcinogenic PAHs in combustion emissions was not correlated with mutagenicity. ► The golden wattle, an invasive species, produced no mutagenic emissions. - Wood smoke from fireplace burning of dominant forest species displayed strong mutagenic activity without a significant correlation with carcinogenic PAHs emission factors.

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

Science.gov (United States)

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

OpenAIRE

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

Mutagenicity of irradiated solutions of nuclei acid bases and nucleosides in Salmonella typhimurium

International Nuclear Information System (INIS)

Wilmer, J.; Schubert, J.

1981-01-01

Solutions of nucleic acid bases, nucleosides and a nucleotide, saturated with either N 2 , N 2 O or O 2 , were irradiated and tested for mutagenicity towards Salmonella typhimurium, with and without pre-incubation. Irradiated solutions of the nuclei acid bases were all non-mutagenic. Irradiated solutions of the nucleosides showed mutagenicity in S. typhimurium TA100 (pre-incubation assay). Generally, the mutagenicity followed the order: N 2 O > N 2 > O 2 . The results show that the formation of mutagenic radiolytic products is initiated by attack of mainly solutions of the nucleotide thymidine-5'-monophosphate, no mutagenicity could be detected. (orig.)

Formation of new heterocyclic amine mutagens by heating creatinine, alanine, threonine and glucose.

Science.gov (United States)

Skog, K; Knize, M G; Felton, J S; Jägerstad, M

1992-08-01

A mixture of alanine, threonine, creatinine and glucose was heated in diethylene glycol and water (5:1, v/v) for 15 min at 200 degrees C. The mutagens formed were purified by high-performance liquid chromatography using the Ames/Salmonella mutagenic activity to guide the purification. The structures of the purified mutagens were determined using UV absorption, mass and NMR spectrometry. A new mutagenic compound with a mass number of 217 was found and its mass spectrum did not correspond to any known mutagen derived from food. This new compound accounted for 4% of the total mutagenic activity. Other mutagenic compounds were identified as MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline), and a new mutagen 4,7,8-TriMeIQx (2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline) with a mutagenic activity of 73,000 TA98 revertants per microgram. The percentage of the mutagenic activity attributable to MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10%, 70% and 3%, respectively. The yield of MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10, 36 and 6 nmole/mmole creatinine. The formation of TriMeIQx from natural meat components suggests that this new quinoxaline mutagen may be present in cooked foods.

Cooking with Fire: The Mutagenicity- and PAH-Emission ...

Science.gov (United States)

Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. We evaluated two categories of solid-fuel cookstoves for 8 pollutant- and 4 mutagenicity-emission factors, correlated the mutagenicity-emission factors, and compared them to those of other combustion emissions. We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS); we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella. Other than NOx the emission factors per MJd correlated highly among each other (r2 ≥ 0.92); NOx correlated 0.58-0.76 with the other emission factors. Excluding NOx, the NDS and FDS reduced the emission factors on average 68 and 92%, respectively, relative to the TSF. Nonetheless, the mutagenicity-emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was intermediate to that of a large diesel bus engine and a small diesel generator. Both mutagenicity- and pollutant-emission factors may be informative for characterizing cookstove

Kaempferol, a mutagenic flavonol from Helichrysum simillimum.

Science.gov (United States)

Elgorashi, Ee; van Heerden, Fr; van Staden, J

2008-11-01

Helichrysum simillimum is native to South Africa. It is used for the treatment of coughs, colds, fever, infections, headache, and menstrual pain. Extracts of this species showed mutagenic effects in the Salmonella/microsome assay. The aim of this study was to isolate and determine the mutagenic constituents of H. simillimum. Bioassay-guided fractionation of 90% aqueous methanol extracts, using Salmonella typhimurium TA98, led to the isolation of the flavonol kaempferol.

Studies on mutagenic effectiveness and efficiency in Fenugreek ...

African Journals Online (AJOL)

shagufta

2013-05-01

May 1, 2013 ... improvement, the basic studies on effectiveness and efficiency of a mutagen in a crop are necessary to recover high frequency of desirable mutations (Kumar and Mani, 1997; Badere and Chaudhary, 2007). Mutagenic effectiveness is an index of the response of a genotype to the increasing doses of the ...

How stable are the mutagenic tautomers of DNA bases?

Directory of Open Access Journals (Sweden)

Brovarets’ O. O.

2010-02-01

Full Text Available Aim. To determine the lifetime of the mutagenic tautomers of DNA base pairs through the investigation of the physicochemical mechanisms of their intramolecular proton transfer. Methods. Non-empirical quantum chemistry, the analysis of the electron density by means of Bader’s atom in molecules (AIM theory and physicochemical kinetics were used. Results. Physicochemical character of the transition state of the intramolecular tautomerisation of DNA bases was investigated, the lifetime of mutagenic tautomers was calculated. Conclusions. The lifetime of the DNA bases mutagenic tautomers by 3–10 orders exceeds typical time of DNA replication in the cell (~103 s. This fact confirms that the postulate, on which the Watson-Crick tautomeric hypothesis of spontaneous transitions grounds, is adequate. The absence of intramolecular H-bonds in the canonical and mutagenic tautomeric forms determine their high stability

Effect of mutagen combined action on Chlamydomonas reinhardtii cells. I. Lethal effect dependence on the sequence of mutagen application and on cultivation conditions

Energy Technology Data Exchange (ETDEWEB)

Vlcek, D; Podstavkova, S; Dubovsky, J [Komenskeho Univ., Bratislava (Czechoslovakia). Prirodovedecka Fakulta

1978-01-01

The effect was investigated of single and combined actions of alkylnitrosourea derivatives (N-methyl-N-nitrosourea and N-ethyl-N-nitrosourea) and UV-radiation on the survival of cells of Chlamydomonas reinhardtii algae in dependence on the sequence of application of mutagens and on the given conditions of cultivation following mutagen activity. In particular, the single phases were investigated of the total lethal effect, i.e., the death of cells before division and their death after division. The most pronounced changes in dependence on the sequence of application of mutagens and on the given conditions of cultivation were noted in cell death before division. In dependence on the sequence of application of mutagens, the effect of the combined action on the survival of cells changed from an additive (alkylnitrosourea + UV-radiation) to a protective effect (UV-radiation + alkylnitrosourea).

Structural features of nitroaromatics that determine mutagenic activity in Salmonella typhimurium

International Nuclear Information System (INIS)

Vance, W.A.; Levin, D.E.

1984-01-01

Seventeen structurally homologous nitroaromatics were tested for direct-acting mutagenic potency in nine strains of Salmonella typhimurium. The following four structural features were determined to have a strong influence on mutagenic activity: physical dimensions of the aromatic rings, isomeric position of the nitro group, conformation of the nitro group with respect to the plane of the aromatic rings, and ability to resonance-stabilize the utimate electrophile. Progressive addition of five- and six-membered rings to a nitrobenzene nucleus demonstrated that mutagenic activity was a direct function of size. Nitroaromatics with a nitro group oriented along the long axis of symmetry of the molecule were more potent mutagens that those with the nitro group oriented along the short axis. These results are discussed in light of the insertion-denaturation model for intercalation of certain DNA adducts. Finally, structural features that contribute to resonance stabilization of the reactive nitrenium ion enhance mutagenic potency. The predictive value of these structure-activity relationships should permit a first approximation in the assessment of mutagenic potency of nitroaromatics

Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

OpenAIRE

Seed, J L

1982-01-01

The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

Induction of forward gene mutations in saccharomycetes. Comparison of efficiencies of different mutagens

International Nuclear Information System (INIS)

Zakharov, I.A.; Gracheva, L.M.; Ivanov, E.L.; Koval'tsova, S.V.; Kozhina, T.N.; Korolev, V.G.; Fedorova, I.V.; Shanshiashvili, T.A.; Yadgarov, Kh.T.

1981-01-01

The data on the induction of forward mutations in locus ade 2 of the wild haploid of Saccharomyces cerevisiae yeasts by three types of mutagens-chamical mutagens, various radiations and defferent isotopes incorporated in the cell - are generalyzed. The ratio of mutation frequency observed at different doses of mutagen to the survival rate logarithm for the same doses is expressed as rectilinear regression M=m(-1 nS). The application of the same mutation system in the case of all studied mutagens allows to consider the inclination value ''m'' to be the characteristic of mutagen efficiency. We propose to call the ratio of the efficiency of a given mutagen to the efficiency of γ-rays (msub(x)/msub(γ)) - the relative mutagenous effifiency (RME). According to the decrease of this index the studied mutagens have stood in the following succession: ethylene imine (EI), nitrosomethylurea (NMU) 89 Sr, UV rays, 35 S, 91 Y, 33 P, 32 P, acridine-yprite, β-radiation ( 32 P), γ-rays, hard X-rays, 3 H, soft X-rays, neutrons, 125 I [ru

Radiation-induced mutagenicity and lethality in tryptophan-requiring auxotrophs of escherichia coli

International Nuclear Information System (INIS)

Xu Rong; Qian Hongwei; Yao Fenying; Gu Shuzhu; Xu Jiaxin; Bi Hekan; Liu Yuying

1989-01-01

Mutation and killing caused by X-ray radiation and 60 Co γ-ray radiation were studied in three different tryptophan-requiring auxotrophs (WP2, Wp2A, Cm 891) of Escherichia coli. These testers are sensitive to base pair substitution mutagens. Cm891 carries a R-factor and is more sensitive than WP2 and WP2A to radiation-induced mutation and lethality. The results of the study show that (1) ionizing radiation was mutagenic to E. coli, (2) the order of mutagenic sensitivity among three strains to ionizing radiation was Cm891 > WP2A > WP2, (3) the dose rate of γ-ray influences mutagenicity and lethalty of E. coli strain, (4) the toxicity and mutagenicity of γ-ray were similar to X-ray when Cm891 was tested, however, γ-ray was more toxic and mutagenic than X-ray to WP2A ang WP2

Can Spirulina maxima reduce the mutagenic potential of sibutramine?

Science.gov (United States)

Araldi, R P; Santos, N P; Mendes, T B; Carvalho, L B; Ito, E T; de-Sá-Júnior, P L; Souza, E B

2015-12-28

The worldwide obesity pandemic requires the use of anti-obesity drugs. Sibutramine is an anti-obesity drug that has been used worldwide but is indiscriminately consumed in Brazil. Several studies have demonstrated that sibutramine promotes weight loss and weight maintenance, but several side effects have been associated with its systematic consumption. For this reason, sibutramine was withdrawn from the European and American markets, but still remains legal for use in Brazil. Studies have shown that a 5-10% reduction in body weight results in outstanding health benefits for obese patients. However, in order to promote significant weight loss, it is necessary to use sibutramine for at least 2 years. This long-term exposure has carcinogenic potential, as sibutramine causes DNA damage. Thus, this study evaluated the in vivo mutagenic potential of sibutramine alone (5, 7, 10, 15, and 20 mg/kg) and in association with Spirulina maxima (150 and 300 mg/kg), a cyanobacterium with antioxidant potential, using the polychromatic erythrocyte micronucleus test. Our results reinforced the mutagenic potential of sibutramine alone, which showed a time-dependent action. Combinatory treatments with S. maxima were not able to reduce the genotoxicity of sibutramine. These results were confirmed in vitro with the cytokinesis-blocked micronucleus test. In conclusion, our data showed that new alternative anti-obesity treatments are needed since the consumption of sibutramine can increase the risk of cancer in overweight patients.

Hygiene assessment of irradiated potato mutagenic activity

International Nuclear Information System (INIS)

Uralova, M.; Grunt, J.; Patzeltova, N.

1977-01-01

Albino rat males were fed on gamma-irradiated potatoes for one month and mated with two intact female rats each. The dominant lethal mutation method was then used for the study of possible mutagenic activity of the irradiated potatoes. No statistically significant differences were observed and no mutagenic activity was found. Thus, the test showed that potatoes irradiated with a dose of 10 krad of gamma radiation does not present genetic hazards for albino rats. (L.O.)

Use of genetic toxicity data in GHS mutagenicity classification and labeling of substances.

Science.gov (United States)

Ball, Nicholas S; Hollnagel, Heli M

2017-06-01

One of the key outcomes of testing the potential genotoxicity or mutagenicity of a substance is the conclusion on whether the substance should be classified as a germ cell mutagen and the significance of this for other endpoints such as carcinogenicity. The basis for this conclusion are the criteria presented in classification and labelling systems such as the Globally Harmonized System for classification and labeling (GHS). This article reviews the classification criteria for germ cell mutagenicity and carcinogenicity and how they are applied to substances with evidence of mutagenicity. The implications and suitability of such a classification for hazard communication, risk assessment, and risk management are discussed. It is proposed that genotoxicity assessments should not focus on specifically identifying germ cell mutagens, particularly given the challenges associated with communicating this information in a meaningful way. Rather the focus should be on deriving data to characterize the mode of action and for use in the risk assessment of mutagens, which could then feed into a more robust, risk based management of mutagenic substances versus the current more hazard based approaches. Environ. Mol. Mutagen. 58:354-360, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Induction of Abasic Sites by the Drinking-Water Mutagen MX in Salmonella TA100

Science.gov (United States)

Mutagen X (MX) is a chlorinated furanone that accounts for more of the mutagenic activity of drinking water than any other disinfection by-product. It is one of the most potent base-substitution mutagens in the Salmonella (Ames) mutagenicity assay, producing primarily GC to TA mu...

Assessment of Cellular Mutagenicity of Americano Coffees from Popular Coffee Chains.

Science.gov (United States)

Liu, Zhen-Shu; Chen, Po-Wen; Wang, Jung-Yu; Kuo, Tai-Chen

2017-09-01

Coffee is a popular beverage worldwide, but coffee beans can be contaminated with carcinogens. The Ames Salmonella mutagenicity test is often used for analysis of carcinogens for mutagenicity. However, previous studies have provided controversial data about the direct mutagenicity of coffee beans based on Ames test results. This study was conducted to determine the mutagenicity of popular Americano coffee based on results from the Ames test. Coffee samples without additives that were served by five international coffee chain restaurants were subjected to the analysis using Salmonella Typhimurium tester strains TA98, TA100, and TA1535. The levels of bacterial revertants in samples from coffee chains were lower than the twofold criterion of the control sets, and no significant dose-response effect was observed with or without rat liver enzyme activation. These data indicate that Americano coffees from the selected coffee chains possessed no direct mutagenic activity with or without enzyme activation. These findings suggest a low mutagenic risk from Americano coffees served by the selected coffee chains and support the use of other methods to confirm the nonmutagenicity of coffee products. These results are consistent with most recent epidemiological reports.

Evaluation of different treatment processes with respect to mutagenic activity in drinking water

Energy Technology Data Exchange (ETDEWEB)

Kool, H J; Hrubec, J; van Kreijl, C F; Piet, G J

1985-12-01

Treatment processes which are applied in The Netherlands during the preparation of drinking water have been evaluated with regard to introduction and removal of organic mutagens as well as halogenated organics. It appeared that the most efficient processes in reducing mutagenic activity were activated carbon filtration and artificial dune recharge. In general these processes were also the most efficient in removing halogenated organics. Using low doses of chlorine dioxide (less than 1 mg C1O2/l) for safety disinfection of drinking water, no change or substantial less mutagenic activity than by chlorination (1 mg Cl/l) was found. This counts too for the formation of halogenated organics. Transport chlorination of stored river Meuse water was able to introduce or activate mutagenic nitro organics which have not been found previously. Ozone treatment under field conditions showed mostly a tendency to decrease the activity of organic mutagens. It was also shown that dependent on the water quality and treatment conditions a slight increase of mutagenic activity occurred, but this activity would be reduced by increasing the ozone dose. It seems possible to optimize the ozone treatment conditions regarding the level of ozone dose and the contact time to avoid an increase of mutagenic activity. Furthermore it was shown that when a mutagenic raw water source was used a proper combination of treatment processes is able to produce drinking water in which no mutagenic activity could be detected under the test conditions. Finally it is stated that before far-reaching decisions with respect to use mutagenicity data for a selection of water sources or treatment processes will be made, more information on the relation mutagenic activity from drinking water and effects on human health should become available.

Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

Energy Technology Data Exchange (ETDEWEB)

Valerio, Luis G., E-mail: luis.valerio@fda.hhs.gov [Science and Research Staff, Office of Pharmaceutical Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993–0002 (United States); Cross, Kevin P. [Leadscope, Inc., 1393 Dublin Road, Columbus, OH, 43215–1084 (United States)

2012-05-01

Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structure–activity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ► We characterize a new in silico model to predict mutagenicity of drug impurities. ► The model predicts Salmonella mutagenicity and will be useful for safety assessment. ► We examine toxicity fingerprints and toxicophores of this Ames assay model. ► We compare these attributes to those found in drug impurities known to FDA/CDER. ► We validate the model and find it has a desired predictive

Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

International Nuclear Information System (INIS)

Valerio, Luis G.; Cross, Kevin P.

2012-01-01

Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structure–activity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ► We characterize a new in silico model to predict mutagenicity of drug impurities. ► The model predicts Salmonella mutagenicity and will be useful for safety assessment. ► We examine toxicity fingerprints and toxicophores of this Ames assay model. ► We compare these attributes to those found in drug impurities known to FDA/CDER. ► We validate the model and find it has a desired predictive performance.

Mutagenic and carcinogenic properties of drinking water

International Nuclear Information System (INIS)

Kool, H.J.; van Kreijl, C.F.; Hrubec, J.

1985-01-01

In this chapter results of oxidation treatments with chlorine, ozone, chlorine dioxide, and ultraviolet (UV), with respect to their effects on activity (Ames test) in drinking water supplies are reviewed. In addition, the authors present the preliminary results of a pilot plant study on the effects of chlorine and chlorine dioxide on mutagenicity. Furthermore, results of several carcinogenicity studies performed with organic drinking water concentrates are discussed in relation to the results of a Dutch carcinogenicity study with mutagenic drinking water concentrates

THE GENOTOXICITY OF AMBIENT OUTDOOR AIR, A REVIEW: SALMONELLA MUTAGENICITY

Science.gov (United States)

The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicityAbstractMutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

The detection and analysis of mutagens: Final report, 1968--1986

International Nuclear Information System (INIS)

Ames, B.N.

1989-01-01

Our main objectives are: to develop and improve the Salmonella test for detecting environmental mutagens; to investigate the relationship between carcinogens and mutagens and to validate the Salmonella test for detecting carcinogens; to uncover significant unsuspected environmental mutagens/carcinogens; to investigate the theory of mutagenesis; to develop new methods for determining DNA damage by particular chemicals in individual people; to understand the role of oxygen radicals in DNA damage, cancer, and aging; and to investigate the role of anti-carcinogens in preventing DNA damage

Exposure to meat-derived carcinogens and bulky DNA adduct levels in normal-appearing colon mucosa.

Science.gov (United States)

Ho, Vikki; Brunetti, Vanessa; Peacock, Sarah; Massey, Thomas E; Godschalk, Roger W L; van Schooten, Frederik J; Ashbury, Janet E; Vanner, Stephen J; King, Will D

2017-09-01

Meat consumption is a risk factor for colorectal cancer. This research investigated the relationship between meat-derived carcinogen exposure and bulky DNA adduct levels, a biomarker of DNA damage, in colon mucosa. Least squares regression was used to examine the relationship between meat-derived carcinogen exposure (PhIP and meat mutagenicity) and bulky DNA adduct levels in normal-appearing colon tissue measured using 32 P-postlabelling among 202 patients undergoing a screening colonoscopy. Gene-diet interactions between carcinogen exposure and genetic factors relevant to biotransformation and DNA repair were also examined. Genotyping was conducting using the MassARRAY ® iPLEX ® Gold SNP Genotyping assay. PhIP and higher meat mutagenicity exposures were not associated with levels of bulky DNA adducts in colon mucosa. The XPC polymorphism (rs2228001) was found to associate with bulky DNA adduct levels, whereby genotypes conferring lower DNA repair activity were associated with higher DNA adduct levels than the normal activity genotype. Among individuals with genotypes associated with lower DNA repair (XPD, rs13181 and rs1799179) or detoxification activity (GSTP1, rs1695), higher PhIP or meat mutagenicity exposures were associated with higher DNA adduct levels. Significant interactions between the XPC polymorphism (rs2228000) and both dietary PhIP and meat mutagenicity on DNA adduct levels was observed, but associations were inconsistent with the a priori hypothesized direction of effect. Exposure to meat-derived carcinogens may be associated with increased DNA damage occurring directly in the colon among genetically susceptible individuals. Copyright © 2017 Elsevier B.V. All rights reserved.

Urine mutagenicity of steel workers exposed to coke oven emissions

Energy Technology Data Exchange (ETDEWEB)

De Meo, M.P.; Dumenil, G.; Botta, A.H.; Laget, M.; Zabaloueff, V.; Mathias, A.

1987-03-01

Urine mutagenicity of 19 individuals was investigated at a steel mill. All the subjects worked on the coal processing unit. Urine samples were collected at the end of a working day. Urine samples of two exposed workers were collected at the end of two periods of rest and two periods of working. Mutagens were extracted on XAD-2 resin and tested by the Salmonella microsomal assay and the SOS spot test. Mutagenic potencies of exposed smokers and exposed non-smokers were 8.62 +/- 6.56 and 1.1 +/- 0.48 revertants/mg creatinine respectively with Salmonella typhimurium strain TA98 + S9. Both values were significantly higher than those of unexposed smokers and non-smokers (5.07 +/- 3.33 and 0.47 +/- 0.72 revertants/mg creatinine respectively). The urinary mutagenic potency of the two exposed individuals increased at the end of periods of working (15.97 +/- 2.57 revertants/mg creatinine) and decreased at the end of periods of rest (12.31 +/- 2.45 revertants/mg creatinine). Urinary mutagens were detected with S. typhimurium strain TA100 + S9 to a lesser extent. No direct-acting mutagens were detected by the SOS spot test. Atmospheric benzo(a)pyrene (BaP) were also measured by h.p.l.c. on the coke battery. BaP concentrations ranged between 0.01 and 0.6 microgram/m3 air at the different working sites. Biological monitoring with short-term tests is discussed.

Effect of mutagen combined action on Chlamydomonas Reinhardtii cells. I

International Nuclear Information System (INIS)

Vlcek, D.; Podstavkova, S.; Dubovsky, J.

1978-01-01

The effect was investigated of single and combined actions of alkylnitrosourea derivatives (N-methyl-N-nitrosourea and N-ethyl-N-nitrosourea) and UV-radiation on the survival of cells of Chlamydomonas reinhardtii algae in dependence on the sequence of application of mutagens and on the given conditions of cultivation following mutagen activity. In particular, the single phases were investigated of the total lethal effect, i.e., the death of cells before division and their death after division. The most pronounced changes in dependence on the sequence of application of mutagens and on the given conditions of cultivation were noted in cell death before division. In dependence on the sequence of application of mutagens, the effect of the combined action on the survival of cells changed from an additive (alkylnitrosourea + UV-radiation) to a protective effect (UV-radiation + alkylnitrosourea). (author)

A contribution to the study on the mutagenicity of atmospheres

International Nuclear Information System (INIS)

Blaise, Philipp

1986-01-01

Following a review of the literature, the genotoxic hazards of atmospheric pollutants at various locations (rural sites, motorway tolls, paint shops...) were evaluated by in vitro mutagenicity assays (Ames' test and SOS chromo-test) and analytical methods (gas chromatography and mass spectrometry). Instrumentation and procedures were developed for the sampling of volatile organic pollutants: adsorption on XAD 2 followed by acetone extraction of the compounds trapped. A comparative study allowed to assess the relative mutagenic action of the volatile organic compounds and to establish a mutagenicity scale. (author) [fr

[Smoked sausages and food additives: evaluation of total mutagenic activity].

Science.gov (United States)

Dugan, A M; Tkacheva, D L

2011-01-01

The paper deals with the evaluation of the total mutagenic activity of samples of the inorganic and organic fractions of three technology smoked sausages (boiled-smoked, semi-smoked, and raw-smoked) and some food additives used to manufacture the above sausages. Their mild and moderate mutagenic effects were recorded in a Salmonella typhimurium bacterial test system with a metabolic activation system. Physicochemical analysis of the fractions of the smoked sausages has shown that their study samples are substantially contaminated with heavy metals and representatives of polycyclic aromatic hydrocarbons, partially causing the mutagenic effects observed.

Induction of two mutants in birdsfoot trefoil (Lotus corniculatus) by x-rays and chemical mutagens

International Nuclear Information System (INIS)

Therrien, M.C.; Grant, W.F.

1982-01-01

The mutagenic effects of X-rays, ethyl methanesulfonate (EMS), 8-ethoxycaffeine (EOC), N-hydroxyurea (HU) and 2-aminopurine (2AP) on seed treatment of birdsfoot trefoil (Lotus corniculatus L. 'Mirabel') were assessed over four generations. Mutants were recovered in the M 2 , M 3 and M 4 generations from selfed lines, from crosses derived form selfed lines and from open pollination lines. Mutant plants exhibiting vestigial floret character were recovered from X-rays, EMS, EOC and HU treatments. Mutant chlorotica plants were obtained from EMS treatment only. No mutants were recovered from 2AP treatment, EMS, the most effective mutagen, produced nine vestigial floret and 12 chlorotica mutants. Mutants were obtained from only one exposure of X-rays (12 krad). There was evidence for preferential elimination of gametes. The chlorotica and vestigial floret mutants were inherited as tetrasomic recessives. Mutation frequencies of 0.4 - 3.1% in a tetrasomic background are indicative of the effectiveness of EMS in birdsfoot trefoil

Induction of two mutants in birdsfoot trefoil (Lotus corniculatus) by x-rays and chemical mutagens

Energy Technology Data Exchange (ETDEWEB)

Therrien, M.C.; Grant, W.F. (McGill Univ., Ste. Anne de Bellevue, Quebec (Canada). Macdonald Coll.)

1982-10-01

The mutagenic effects of X-rays, ethyl methanesulfonate (EMS), 8-ethoxycaffeine (EOC), N-hydroxyurea (HU) and 2-aminopurine (2AP) on seed treatment of birdsfoot trefoil (Lotus corniculatus L. 'Mirabel') were assessed over four generations. Mutants were recovered in the M/sub 2/, M/sub 3/ and M/sub 4/ generations from selfed lines, from crosses derived form selfed lines and from open pollination lines. Mutant plants exhibiting vestigial floret character were recovered from X-rays, EMS, EOC and HU treatments. Mutant chlorotica plants were obtained from EMS treatment only. No mutants were recovered from 2AP treatment, EMS, the most effective mutagen, produced nine vestigial floret and 12 chlorotica mutants. Mutants were obtained from only one exposure of X-rays (12 krad). There was evidence for preferential elimination of gametes. The chlorotica and vestigial floret mutants were inherited as tetrasomic recessives. Mutation frequencies of 0.4 - 3.1% in a tetrasomic background are indicative of the effectiveness of EMS in birdsfoot trefoil.

Evaluation of mutagenic potential of contaminated atmosphere at Ibirapuera Park, Sao Paulo - SP, Brazil, using the Tradescantia stamen-hair assay

International Nuclear Information System (INIS)

Ferreira, Maria Izildinha; Domingos, Marisa; Gomes, Heliana de A; Saldiva, Paulo H.N.; Assuncao, Joao V. de

2007-01-01

Trad-SHM assay was used to check mutagenic potential of atmospheric contamination at Ibirapuera Park, located in Sao Paulo city, Brazil, and variation of risk along the year, besides determining which Tradescantia clone, BNL 4430 or KU-20, better indicates risk. Thirty pots of both clones were exposed during one-year period (September, 2002-August, 2003). Twenty inflorescences were taken from each clone twice a month in the morning, in order to estimate the frequency of mutations in stamen hairs. Results were compared to air pollution and climatic data measured next to the exposure site. KU-20 showed stamen-hair mutations greater than BNL 4430. Greatest mutation rates in KU-20 were observed in condition of high monthly mean of NO 2 and average peak concentrations of NO during the day, indicating that mutagenic effects originated from vehicular pollution. Clone KU-20 revealed to be more appropriate for biomonitoring purposes at the Park. - Clone KU-20 showed to be more appropriate than clone BNL 4430 to indicate vehicular pollution mutagenic risks in Trad-SHM assay

40 Years of the Salmonella Mutagenicity Assay: Implications for 21st Century Toxicology

Science.gov (United States)

The Salmonella (Ames) mutagenicity assay was developed and introduced by Bruce Ames and colleagues in 1971. Since then, it has become the standard assay for hazard identification of mutagens worldwide. It is a first-tier test for mutagenic activity in the pharmaceutical and chemi...

Mutagenicity of basic fractions derived from lamb and beef cooked by common household methods.

Science.gov (United States)

Barrington, P J; Baker, R S; Truswell, A S; Bonin, A M; Ryan, A J; Paulin, A P

1990-03-01

Mutagen production was examined in lamb and beef in relation to certain common household cooking methods. Mutagenicity was assessed, after extraction of the basic fraction of cooked meat samples, using Salmonella typhimurium strain TA1538 with added rat-liver S-9 homogenate. Little or no mutagenicity was found in barbecued lamb chops, in microwave-cooked lamb chops, sirloin steak, leg of lamb, or rolled beef loaf, in roasted leg of lamb or rolled beef loaf, in stewed blade steak or in boiled chuck steak. However, the basic fraction from well-done, edible fried or grilled meat contained mutagenic activity equivalent to approximately 30,000 TA1538 revertants/100 g cooked meat. It was found tht the mutagenic activity of grilled lamb chops, sirloin and rump steaks was directly related to the average surface temperatures attained during cooking. Use of butter as a frying medium was particularly associated with higher mutagenicity in meat samples. Fried meats (rump and fillet steaks) generally yielded higher mutagenic activity than did grilled meats (rump steak, lamb chops) at comparable temperatures of the cooking medium. Using similar cooking procedures, lamb did not differ markedly from beef in mutagenic activity.

Mutagenicity of comfrey (Symphytum Officinale) in rat liver

OpenAIRE

Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

2005-01-01

Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

Mutagenicity of comfrey (Symphytum Officinale) in rat liver.

Science.gov (United States)

Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

2005-03-14

Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

Role of ozone and granular activated carbon in the removal of mutagenic compounds.

Science.gov (United States)

Bourbigot, M M; Hascoet, M C; Levi, Y; Erb, F; Pommery, N

1986-01-01

The identification of certain organic compounds in drinking water has led water treatment specialists to be increasingly concerned about the eventual risks of such pollutants to the health of consumers. Our experiments focused on the role of ozone and granular activated carbon in removing mutagenic compounds and precursors that become toxic after chlorination. We found that if a sufficient dose of ozone is applied, its use does not lead to the creation of mutagenic compounds in drinking water and can even eliminate the initial mutagenicity of the water. The formation of new mutagenic compounds seems to be induced by ozonation that is too weak, although these mutagens can be removed by GAC filtration. Ozone used with activated carbon can be one of the best means for eliminating the compounds contributing to the mutagenicity of water. A combined treatment of ozone and activated carbon also decreases the chlorine consumption of the treated water and consequently reduces the formation of chlorinated organic compounds. PMID:3816720

Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates.

Science.gov (United States)

Pool, B L; Lin, P Z

1982-08-01

Smokehouse smoke, which is used for flavouring meat products, was investigated for its mutagenic activity in the Salmonella typhimurium assay. We were chiefly concerned with the fractions free of polycyclic aromatic hydrocarbons but containing phenol compounds, which are responsible for the preservative and aromatizing properties of the smoke. The most abundantly occurring phenol compounds (phenol, cresols, 2,4-dimethylphenol, brenzcatechine, syringol, eugenol, vanilline and guaiacol) gave negative results when they were tested for mutagenicity at five concentrations up to 5000 micrograms/plate, with and without S-9 mix, using five strains of S. typhimurium. Even when phenol was further investigated in a variety of test conditions, no induction of his+ revertants was observed. When smokehouse smoke was condensed and fractionated the majority of the various phenolic fractions also gave negative results when tested at five concentrations using five strains of S. typhimurium. However there was a slight increase in the number of revertants in a few cases. The presence in the phenolic fractions of very small amounts of mutagenic impurities, the nature of which needs further investigation, cannot be excluded. These results support the further development of non-hazardous smoke-aroma preparations, based on the phenolic components of smokehouse smoke.

Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates

Energy Technology Data Exchange (ETDEWEB)

Pool, B.L.; Lin, P.Z.

1982-08-01

Smokehouse smoke, which is used for flavouring meat products, was investigated for its mutagenic activity in the Salmonella typhimurium assay. We were chiefly concerned with the fractions free of polycyclic aromatic hydrocarbons but containing phenol compounds, which are responsible for the preservative and aromatizing properties of the smoke. The most abundantly occurring phenol compounds (phenol, cresols, 2,4-dimethylphenol, brenzcatechine, syringol, eugenol, vanilline and guaiacol) gave negative results when they were tested for mutagenicity at five concentrations up to 5000 micrograms/plate, with and without S-9 mix, using five strains of S. typhimurium. Even when phenol was further investigated in a variety of test conditions, no induction of his+ revertants was observed. When smokehouse smoke was condensed and fractionated the majority of the various phenolic fractions also gave negative results when tested at five concentrations using five strains of S. typhimurium. However there was a slight increase in the number of revertants in a few cases. The presence in the phenolic fractions of very small amounts of mutagenic impurities, the nature of which needs further investigation, cannot be excluded. These results support the further development of non-hazardous smoke-aroma preparations, based on the phenolic components of smokehouse smoke.

Absence of mutagenic effects of a particular Symphytum officinale L. liquid extract in the bacterial reverse mutation assay.

Science.gov (United States)

Benedek, Birgit; Ziegler, Andreas; Ottersbach, Peter

2010-03-01

Comfrey (Symphytum officinale L.) root is traditionally used for the topical treatment of contusions, strains and sprains. Besides allantoin and rosmarinic acid, which are discussed as pharmacologically active principles, the drug contains pyrrolizidine alkaloids (PAs) known for their hepatotoxic, carcinogenic and mutagenic properties. The topical herbal medicinal products Kytta-Salbe f and Kytta-Plasma f contain a PA-free liquid extract from comfrey root as active substance. The aim of this study was to demonstrate the absence of genotoxic effects of this special extract in the bacterial reverse mutation assay (Ames test). Briefly, comfrey root liquid extract was investigated for its ability to induce gene mutations in Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 with and without metabolic activation using the mammalian microsomal fraction S9 mix. Reference mutagens were used to check the validity of the experiments. Comfrey root fluid extract showed no biologically relevant increases in revertant colony numbers of any of the five tester strains, neither in the presence nor in the absence of metabolic activation. In conclusion, the comfrey root fluid extract contained in Kytta-Salbe f and Kytta-Plasma f was not mutagenic in the bacterial reverse mutation assay. (c) 2009 John Wiley & Sons, Ltd.

Acrolein- and 4-Aminobiphenyl-DNA adducts in human bladder mucosa and tumor tissue and their mutagenicity in human urothelial cells.

Science.gov (United States)

Lee, Hyun-Wook; Wang, Hsiang-Tsui; Weng, Mao-wen; Hu, Yu; Chen, Wei-sheng; Chou, David; Liu, Yan; Donin, Nicholas; Huang, William C; Lepor, Herbert; Wu, Xue-Ru; Wang, Hailin; Beland, Frederick A; Tang, Moon-shong

2014-06-15

Tobacco smoke (TS) is a major cause of human bladder cancer (BC). Two components in TS, 4-aminobiphenyl (4-ABP) and acrolein, which also are environmental contaminants, can cause bladder tumor in rat models. Their role in TS related BC has not been forthcoming. To establish the relationship between acrolein and 4-ABP exposure and BC, we analyzed acrolein-deoxyguanosine (dG) and 4-ABP-DNA adducts in normal human urothelial mucosa (NHUM) and bladder tumor tissues (BTT), and measured their mutagenicity in human urothelial cells. We found that the acrolein-dG levels in NHUM and BTT are 10-30 fold higher than 4-ABP-DNA adduct levels and that the acrolein-dG levels in BTT are 2 fold higher than in NHUM. Both acrolein-dG and 4-ABP-DNA adducts are mutagenic; however, the former are 5 fold more mutagenic than the latter. These two types of DNA adducts induce different mutational signatures and spectra. We found that acrolein inhibits nucleotide excision and base excision repair and induces repair protein degradation in urothelial cells. Since acrolein is abundant in TS, inhaled acrolein is excreted into urine and accumulates in the bladder and because acrolein inhibits DNA repair and acrolein-dG DNA adducts are mutagenic, we propose that acrolein is a major bladder carcinogen in TS.

Structure-Activity Relationship Models for Rat Carcinogenesis and Assessing the Role Mutagens Play in Model Predictivity

Science.gov (United States)

Carrasquer, C. Alex; Batey, Kaylind; Qamar, Shahid; Cunningham, Albert R.; Cunningham, Suzanne L.

2016-01-01

We previously demonstrated that fragment based cat-SAR carcinogenesis models consisting solely of mutagenic or non-mutagenic carcinogens varied greatly in terms of their predictive accuracy. This led us to investigate how well the rat cancer cat-SAR model predicted mutagens and non-mutagens in their learning set. Four rat cancer cat-SAR models were developed: Complete Rat, Transgender Rat, Male Rat, and Female Rat, with leave-one-out (LOO) validation concordance values of 69%, 74%, 67%, and 73%, respectively. The mutagenic carcinogens produced concordance values in the range of 69–76% as compared to only 47–53% for non-mutagenic carcinogens. As a surrogate for mutagenicity comparisons between single site and multiple site carcinogen SAR models was analyzed. The LOO concordance values for models consisting of 1-site, 2-site, and 4+-site carcinogens were 66%, 71%, and 79%, respectively. As expected, the proportion of mutagens to non-mutagens also increased, rising from 54% for 1-site to 80% for 4+-site carcinogens. This study demonstrates that mutagenic chemicals, in both SAR learning sets and test sets, are influential in assessing model accuracy. This suggests that SAR models for carcinogens may require a two-step process in which mutagenicity is first determined before carcinogenicity can be accurately predicted. PMID:24697549

Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

International Nuclear Information System (INIS)

Ishidate, M. Jr.; Yoshikawa, Kunie; Sofuni, Toshio; Iwahara, Shigeo; Sibuya, Tohru.

1981-01-01

The alcohol extracts freshly prepared from gamma-irradiated potatoes were examined for their mutagenic activity in bacterial and mammalian cell systems. Negative results were obtained from all following test systems: Mutation assays with Salmonella typhimurium His - strains such as TA 100, TA 98, TA 1535, TA 1537, and streptomycin-dependent mutant (SM sup(d)) strain, TA 100 - 10, inductests with Escherichia coli strains, K 12 GY 5027 and K 12 C600, chromosomal aberration tests with Chinese hamster cells in culture, as well as micronucleus tests in mice. In addition, no difference in the mutagenic activities was found between extracts prepared from the irradiated and the unirradiated potatoes, suggesting that no mutagenic substance was produced in potatoes following gamma-irradiation. (author)

Sources of mutagenic activity in urban fine particles

International Nuclear Information System (INIS)

Stevens, R.K.; Lewis, C.W.; Dzubay, T.G.; Cupitt, L.T.; Lewtas, J.

1990-01-01

Samples were collected during the winter of 1984-1985 in the cities of Albuquerque, NM and Raleigh NC as part of a US Environmental Protection Agency study to evaluate methods to determine the emission sources contributing to the mutagenic properties of extractable organic matter (EOM) present in fine particles. Data derived from the analysis of the composition of these fine particles served as input to a multi-linear regression (MLR) model used to calculate the relative contribution of wood burning and motor vehicle sources to mutagenic activity observed in the extractable organic matter. At both sites the mutagenic potency of EOM was found to be greater (3-5 times) for mobile sources when compared to wood smoke extractable organics. Carbon-14 measurements which give a direct determination of the amount of EOM that originated from wood burning were in close agreement with the source apportionment results derived from the MLR model

Counteracting quasispecies adaptability: extinction of a ribavirin-resistant virus mutant by an alternative mutagenic treatment.

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Celia Perales

Full Text Available BACKGROUND: Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. METHODOLOGY AND PRINCIPAL FINDINGS: Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. CONCLUSIONS: (i When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a

Inhibition of mutagenicity of N-methyl-N-nitrosourea by ellagic acid

International Nuclear Information System (INIS)

Dixit, R.; Gold, B.

1986-01-01

Ellagic acid (EA), a plant phenol present in a variety of soft fruits and vegetables, has been shown to possess antimutagenic and anticarcinogenic properties against bay region diol epoxide of polycyclic aromatic hydrocarbons. It is suggested that EA forms an adduct with diol epoxide of benzo (α) pyrene and thus prevents its binding to DNA. To better understand the mechanism of reactivity and inhibition properties of EA, we studied the effect of EA on mutagenicity and DNA alkylation of carcinogenic N-nitroso compounds, including N-methyl-N-nitrosourea (MNU) and N-methyl-N'-nitro-Nnitrosoguanidine (MNNG). MNU and MNNG are direct-acting mutagens requiring no metabolic activation. MNU showed a linear dose response between the concentration range of 50 to 400 nmole in an Ames/Salmonella mammalian mutagenicity test. EA at concentrations of 100, 250, 500, and 1,000 nmole inhibited the mutagenicity of MNU (400 nmole) by 3, 13, 45,and 60%, respectively. MNNG produced a nonlinear dose response in mutagenicity between the concentrations of 0.5 to 4 nmole. EA showed no appreciable inhibition of MNNG mutagenicity. Inhibition of DNA alkylation by MNU and MNNG by EA was studied by preincubating 50 to 200 nmole of EA with 200 nmole of ( 3 H)-MNU or ( 3 H)-MNNG for 10 min at 37 0 c, followed by incubation of polymer deoxyguanosine: deoxycytosine (poly dG:dC) (1 unit) overnight. EA caused no inhibitory effect on MNNG alkylation of poly dG:dC. Experiments on the effect of EA on alkylation of DNA and formation of nucleoside adducts by MNU are in progress, and results will be discussed with reference to MNU and MNNG mutagenicity and EA inhibition

Mutagenic and antimutagenic activities of bioflavonoids and structural analogues in the Ames/Salmonella test

NARCIS (Netherlands)

Mohn GR; Van der Stel JJ; Stavenuiter JFC; Hamzink MRJ; Kreijl CF; LEO; LBO

1996-01-01

The mutagenic and antimutagenic properties of bioflavonoids were determined in the bacterial mutagenicity test of Ames, using Salmonella typhimurium strains TA98 and TA100. The decreasing order of mutagenic activity found in both strains was quercetin>myricetin-kaempferol>morin hydrate. The

Application of the Ames mutagenicity test to food processed by physical preservation methods

International Nuclear Information System (INIS)

Kooij, J.G. van; Leveling, H.B.; Schubert, J.

1978-01-01

An irradiated (380 krad) mixture of four fresh vegetables - leek, celery, carrot, and cauliflower - was examined for mutagenicity by the Ames mutagenicity test using four different histidine-deficient strains of Salmonellae. Water extracts were prepared from the irradiated and unirradiated vegetables - a freeze dried extract (FDE) and a boiled extract (BE). Several problems were overcome in the mutagenicity testing of a complex substance such as food which contains free histidine, different species of bacteria, and a mixture of low and high molecular weight chemicals. In addition, we eliminated an omission in the usual protocols of the Ames test by testing the positive mutagen controls in the presence and absence of the test samples, thus reducing the possible incidence of false negatives and false positives. The induction and expression of mutagenesis by sodium azide (SA) and ethidium bromide (EB) in TA 100 and TA 98 mutant strains, respectively, decreased with increasing amounts of FDE, while increasing levels of BE suppressed the number of revertants in TA 98 in the presence of EB, but exerted little influence on the mutagenicity of SA in TA 100. No difference was observed in the antimutagenic action between the irradiated and unirradiated vegetable extracts. Both the FDE and BE preparations suppressed the action of a frameshift mutagen, but with a base-pair mutagen only the FDE or uncooked vegetable extracts produced suppression. (author)

Assessing Mutagenicity of Methanolic Exteract of Borage Flower (Echium amuenum Using Ames Bioassay

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Meysam Moosavi

2014-08-01

Full Text Available Background: pyrrolizidine alkaloids have been isolated from Echium amuenum. These alkaloids knowing as hepatotoxic, damage the liver. Mutagenicity of pure pyrrolizidine alkaloids has been identified. Thus, the mutagenic effect of the methanolic flower extract was tested using Amest test. Materials and Methods: The long maceration process (for 48 hrs is carried out in order to extract all constitutes. Thin layer chromatography (TLC method was used to evaluate aflatoxin B1 contamination and histidine amino acid presence. Minimum inhibitory concentration (MIC was determined with the dilution method. Salmonella typhimurium strain TA100 was used to determination of mutagenicity. The genotype was confirmed by using histidine requirement, R- factor presence, rfa and uvrB mutations tests. The mutagenicity assay was performed by four extract concentrations (0.25, 0.5, 0.75 and 1mg/ml. Sodium azide (NaN3 and methanol were used as the mutagens (positive control and negative control, respectively in the absence or presence of liver-metabolizing enzymes. Results: The data indicate that Echium amuenum has not significant mutagenic activity against negative control. The presence of liver-metabolizing enzymes did not exhibit a significant change against the properties of extract. Conclusion: It seems that this extensive used plant in traditional medicine, doesn’t contain mutagenic or genotoxic effect in usual doses.

QSAR ligand dataset for modelling mutagenicity, genotoxicity, and rodent carcinogenicity

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Davy Guan

2018-04-01

Full Text Available Five datasets were constructed from ligand and bioassay result data from the literature. These datasets include bioassay results from the Ames mutagenicity assay, Greenscreen GADD-45a-GFP assay, Syrian Hamster Embryo (SHE assay, and 2 year rat carcinogenicity assay results. These datasets provide information about chemical mutagenicity, genotoxicity and carcinogenicity.

Effect of Contemporary Exposure to Mixed Organic Solvents and Occupational Noise on Hearing Thresholds of Workers

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Attarchi Mir Saeid

2010-03-01

Full Text Available Background: Mixed organic solvent exposure, as well as noise, has a wide spread in different industries. In recent years it has been propounded that simultaneous exposure to mixed organic solvents and occupational noise can establish a hearing loss that is more severe than hearing loss due to exposure to each of them separately.Materials & Methods: A descriptive- analytic study was conducted during 2008 in an automobile industry on 441 employees in three different groups. First group were assembly workers that only exposed to noise. The second group included employees in new painting saloon that exposed not only to noise but also to permissible levels of mixed organic solvents and the third group were employees in old painting saloon that exposed to noise and mixed organic solvents in more than threshold limit value (TLV level. The prevalence of hearing loss was compared between three groups on the basis of model 1 (mean hearing threshold in frequencies 0.5, 1 and 2 KHz more than 25dB and model 2 (mean hearing threshold in frequencies 3, 4, 6 and 8 KHz more than 25dB. Results: According to model 2, in workers exposed to noise in addition to mixed organic solvents, the rate of hearing loss, was significantly higher than workers exposed to noise alone (P<0.05, even after adjusting for confounding variables using logistic regression analysis (OR= 4.12 , P<0.001.Conclusion: In workers with simultaneous exposure to mixed organic solvents and noise, special attention must be paid to accurate accomplishment of hearing conservation programs including doing audiometric exams in shorter periods and take advantage of hearing protection devices with higher noise reduction rate (NRR.

Studying the synergistic damage effects induced by 1.8 GHz radiofrequency field radiation (RFR) with four chemical mutagens on human lymphocyte DNA using comet assay in vitro

International Nuclear Information System (INIS)

Wang Baohong; He Jiliang; Jin Lifen; Lu Deqiang; Zheng Wei; Lou Jianlin; Deng Hongping

2005-01-01

The aim of this investigation was to study the synergistic DNA damage effects in human lymphocytes induced by 1.8 GHz radiofrequency field radiation (RFR, SAR of 3 W/kg) with four chemical mutagens, i.e. mitomycin C (MMC, DNA crosslinker), bleomycin (BLM, radiomimetic agent), methyl methanesulfonate (MMS, alkylating agent), and 4-nitroquinoline-1-oxide (4NQO, UV-mimetic agent). The DNA damage of lymphocytes exposed to RFR and/or with chemical mutagens was detected at two incubation time (0 or 21 h) after treatment with comet assay in vitro. Three combinative exposure ways were used. Cells were exposed to RFR and chemical mutagens for 2 and 3 h, respectively. Tail length (TL) and tail moment (TM) were utilized as DNA damage indexes. The results showed no difference of DNA damage indexes between RFR group and control group at 0 and 21 h incubation after exposure (P > 0.05). There were significant difference of DNA damage indexes between MMC group and RFR + MMC co-exposure group at 0 and 21 h incubation after treatment (P 0.05). The experimental results indicated 1.8 GHz RFR (SAR, 3 W/kg) for 2 h did not induce the human lymphocyte DNA damage effects in vitro, but could enhance the human lymphocyte DNA damage effects induced by MMC and 4NQO. The synergistic DNA damage effects of 1.8 GHz RFR with BLM or MMS were not obvious

Wholesomeness studies on gamma-irradiated smoked fish using short-term mutagenicity assays

International Nuclear Information System (INIS)

De la Rosa, A.M.; Banzon, R.B.

1985-12-01

The effect of gamma irradiation on the mutagenicity potential of wood-smoked mackerel (Rastrelliger sp.) was investigated. Smoked fish were irradiated with dose of 2.0, 4.0, 6.0 and 8.0 KGy, and tested for mutagenic activity using the Salmonella plate incorporation assay, host-mediated assay, and micronucleus test. The DMSO extract of unirradiated smoked fish was found to be mutagenic, without metabolic activation in Salmonella strains TA 100 and TA 104, both sensitive to base-pair substitution mutations. Strains TA 98 and TA 97 which are sensitive to frameshift mutations showed no mutagenic activity towards the same DMSO extract. The observed response towards the Salmonella strains was not affected by irradiation in the range of radiation doses studied. The presence of protamutagens in the DMSO extract of unirradiated smoked fish was not detected using the host-mediated assay. In another in-vivo test however, the same DMSO extract induced the formation of micronuclei in the bonemarrow cells of mice. Gamma irradiation up to a dose of 8.0 KGy did not affect the observed mutagenicity of wood-smoked fish. (author)

Mutagenicity and chemical characterization of two petroleum distillates.

Science.gov (United States)

Carver, J H; MacGregor, J A; King, R W

1984-08-01

To investigate if the Salmonella/microsome assay could reliably screen complex petroleum samples for their carcinogenic potential, two high boiling (700-1070 degrees F) petroleum distillates with known activity in a dermal carcinogenesis bioassay were fully characterized with respect to their hydrocarbon composition and polynuclear aromatic hydrocarbon (PNA) content and assayed for mutagenic activity. Mutagenicity assays were also carried out on the aromatic hydrocarbon aggregates separated from these oils by adsorption chromatography. The composition of the distillates differed substantially, and reflected the fact that they were derived from crude oils that were extremely divergent in hydrocarbon character. Both the distillate and aromatic samples consistently induced a very slight increase in revertant TA98 and TA100 colonies; however, an increase of 2-4-fold over background was observed when the S-9 concentration was increased 5-10 times that of the standard assay. The maximal response was less than that expected from the samples' known PNA content and observed potency in the dermal carcinogenesis bioassay. In the Salmonella/microsome assay, all samples inhibited the mutagenic activity of added benzo[a]pyrene. Discordance between the magnitude of the samples' mutagenic activity and their known PNA content may be related to direct or indirect inhibition of sample PNAs by other components of the complex petroleum fractions. Observed inhibitory effects support the use of elevated S-9 concentration in the in vitro assays assessing the carcinogenic potential of petroleum-derived materials.

Studies on mutagenic effect on genetic variability in green gram (Vigna radiata (L. ) Wilczek)

Energy Technology Data Exchange (ETDEWEB)

Krishnaswami, S; Rathinam, M [Tamil Nadu Agricultural Univ. Coimbatore (India). Dept. of Agricultural Botany

1982-03-01

With a view to finding out the effect of mutagenic treatments on heritability in green gram, two cultivars, showing extremes of sensitivity to mutagen, were subjected to two levels each of gamma irradiation and EMS separately and conjointly and the M/sub 2/ generation raised. Families of the higher dose in each treatment were advanced to the M/sub 3/ and the genetic parameters of the various growth and yield attributes, besides seed yield, studied. Barring plant height, heritability of all other traits registered an increase under the mutagen effect. No consistency was evident in the superiority of one mutagen over the other, their behaviour varying with the cultivar and the character studied. Consequent to enhancement in heritability, correlations between the characters underwent alterations under the mutagens.

Combined effects of a chemical mutagen and radiation sterilized diet in mutagenicity and reproduction studies in the same mouse

International Nuclear Information System (INIS)

Renner, H.W.

1975-01-01

The possible intensification of the mutagenic effect of cyclophosphamide (Endoxan) by the feeding of a radiation-sterilized diet (dose, 4.5 Mrad) was studied in 2000 NMRI/Han mice. In a dominant lethal test, males were pretreated with 100 mg Endoxan/kg body weight. The greatest sensitivity towards Endoxan was observed during the late-spermatid stage. No significant differences were detected between the control group (Endoxan plus non-irradiated diet) and the experimental group (Endoxan plus radiation-sterilized diet). In this test, radiation-sterilized feed showed no co-mutagenic effect when combined with Endoxan treatment. In a reproduction study of 7 months duration (continuous mating without lactation periods), the females were treated every 2 wk with 20 mg Endoxan/kg body weight. The decline in litter size with increasing number of litters (i.e. with advancing age of the females) was more pronounced after treatment with the chemical mutagen than in the untreated group. Increases in the frequency of abortions and in premature sterility resulted from Endoxan treatment. During the entire observation period, no effects from the intake of radiation-sterilized food were detected. (author)

Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system

Energy Technology Data Exchange (ETDEWEB)

1992-01-13

The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

Mutagenicity assessment of aerosols in emissions from wood combustion in Portugal.

Science.gov (United States)

Vu, B; Alves, C A; Gonçalves, C; Pio, C; Gonçalves, F; Pereira, R

2012-07-01

Polycyclic aromatic hydrocarbon (PAH) extracts of fine particles (PM(2.5)) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods were Pinus pinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (golden wattle), Quercus faginea (Portuguese oak), Olea europea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start conditions. A mutagenic response was recorded for all species except golden wattle, maritime pine, and briquettes. The mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. These extracts were obtained both from two burning appliances and start-up conditions. However, fireplace seemed to favour the occurrence of mutagenic emissions. The negative result recorded for golden wattle was interesting, in an ecological point of view, since after confirmation, this invasive species, can be recommended for domestic use. Copyright © 2012 Elsevier Ltd. All rights reserved.

Een onderzoek naar het voorkomen van mutagene en/of carcinogene verbindingen in organische concentraten van Nederlands drinkwater alsmede naar de effecten van diverse zuiveringsstappen op de mutagene activiteit

NARCIS (Netherlands)

Kool HJ; van Kreijl CF; Hrubec J; van Oers JAM; Persad S

1987-01-01

In drinkwater, bereid uit oppervlaktewater en grondwater werd in veel gevallen mutagene activiteit aangetoond. Duinfiltratie en actiefkool filtratie verwijderen de mutagene activiteit. Chloring verhoogt die activiteit aanzienlijk, chloordioxide in concentraties kleiner dan 1 mg/l C10-2 leidt tot

Differential response of nascent DNA synthesis and chain elongation in V79 and V79/79 cells exposed to u.v. light and chemical mutagens

International Nuclear Information System (INIS)

Fox, M.; Bloomfield, M.E.; Hopkins, J.; Boyle, J.M.

1983-01-01

DNA repair after u.v., N-methyl-N-nitrosourea (MNU) and ethylmethane sulphonate (EMS) in Chinese hamster V79 cells and the mutagen sensitive derivative V79/79 was investigated. Equal template strand breakage was evident in both cell lines immediately after MNU and EMS exposure and by 4-5 h after MNU the extent of fragmentation was greater in V79/79 cells. After u.v. irradiation template fragmentation was evident in V79/79 but not in V79 cells, even though V79/79 cells failed to excise cyclobutane dimers and repair synthesis was demonstrable in V79 cells but not in V79/79 cells after exposure to all three mutagens. The rate of incorporation of [ 3 H]TdR during semi-conservative DNA synthesis was inhibited equally in a dose dependent manner after u.v. and MNU exposure; incorporation by V79/79 cells was inhibited to a greater extent than by V79 cells after EMS exposure. Nascent DNA synthesis was suppressed more in V79/79 cells than in V79 cells after u.v. but to similar extents in both cell lines after MNU and EMS treatment. Pulse chase experiments indicated a lower rate of elongation of nascent DNA in V79/79 cells after MNU and u.v. exposure but little difference was detectable after EMS. (author)

Analysis of mutagenic and carcinogenic risks: nitrates, nitrites, N-Nitroso compounds. Comparison with radioactive risks

International Nuclear Information System (INIS)

Bittel, R.

1987-07-01

This report comes within the scope of the general studies on mutagenic and carcinogenic agents other than ionizing radiations. Through feeding, way of life and working activities, man is exposed to genotoxic risks of N-nitroso compounds (NNC). In spite of differences in the molecular modes of action, there exists some analogy between the effects of radiation exposures and those of NNC: DNA is the target in either instance. Unlike radiations, NNC are alkylating agents. The whole activation process of carcinogens arises from mechanisms leading to DNA repair [fr

Lack of mutagens in deep-fat-fried foods obtained at the retail level.

Science.gov (United States)

Taylor, S L; Berg, C M; Shoptaugh, N H; Scott, V N

1982-04-01

The basic methylene chloride extract from 20 of 30 samples of foods fried in deep fat failed to elicit any mutagenic response that could be detected in the Salmonella typhimurium/mammalian microsome assay. The basic extracts of the remaining ten samples (all three chicken samples studied, two of the four potato-chip samples, one of four corn-chip samples, the sample of onion rings, two of six doughnuts, and one of three samples of french-fried potato) showed evidence of weak mutagenic activity. In these samples, amounts of the basic extract equivalent to 28.5-57 g of the original food sample were required to produce revertants at levels of 2.6-4.8 times the background level. Only two of the acidic methylene chloride extracts from the 30 samples exhibited mutagenic activity greater than 2.5 times the background reversion level, and in both cases (one corn-chip and one shrimp sample) the mutagenic response was quite weak. The basic extract of hamburgers fried in deep fat in a home-style fryer possessed higher levels of mutagenic activity (13 times the background reversion level). However, the mutagenic activity of deep-fried hamburgers is some four times lower than that of pan-fried hamburgers.

The molecular properties of nitrobenzanthrone isomers and their mutagenic activities.

Science.gov (United States)

Ostojić, Bojana D; Stanković, Branislav; Ðorđević, Dragana S

2014-06-01

The mutagenic activity of five mono-substituted nitrobenzanthrones (NBA) has been determined in the Ames assay (Takamura-Enya et al., 2006). In the present study, a theoretical investigation of the electronic properties of all mono-substituted NBA isomers and their relation to mutagenic activity are presented. Equilibrium geometries, vertical ionization potentials (VIP), vertical electron affinities (VEA), relative energies, dipole moments and electronic dipole polarizabilities, and the IR and Raman spectra of NBA isomers calculated by Density Functional Theory (DFT) methods are presented. The position of the nitro group affects the spectral features of the IR and Raman spectra of the NBA isomers. The results show that a good linear relationship exists between the summation of Raman activities (∑ARaman) over all the 3N-6 vibrational modes and the mutagenic activity of the NBA isomers in Salmonella typhimurium strains. The spectroscopic results suggest that the unknown mutagenic activities of 4-NBA, 5-NBA, 6-NBA, 8-NBA and 10-NBA are predicted to follow the order 4-NBA>10-NBA>5-NBA>8-NBA>6-NBA. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of mutagenic, antimutagenic and genotoxicity effects of Mimosa tenuiflora

Directory of Open Access Journals (Sweden)

Viviane A. Silva

2013-02-01

Full Text Available Genotoxic effects of Mimosa tenuiflora (Willd. Poir, Fabaceae, were investigated by using both micronucleus test and bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100, TA102 respectively. In respect of Ames test results show that the extract does not induce mutations in any strains of Salmonella typhimurium tested since the mutagenicity index is less than 2. In the antimutagenic effect was observed that the extract at the concentrations tested significantly decreased the mutagenicity index of all strains tested which characterized the extract as antimutagenic in these conditions. In the micronucleus test in vivo, we observed that the concentrations used did not induce an increase in the frequency of micronucleus in normochromatic erythrocytes of mice. Therefore, we concluded that the extract of M. tenuiflora is not mutagenic in the absence of exogenous metabolizing system and does not induce an increase in the frequency of the micronucleus characterized as an agent not mutagenic in these conditions. Further studies of toxicity need to be made to the use of this plant in the treatment of diseases to be stimulated.

Assessment of mutagenic, antimutagenic and genotoxicity effects of Mimosa tenuiflora

Directory of Open Access Journals (Sweden)

Viviane A. Silva

2013-04-01

Full Text Available Genotoxic effects of Mimosa tenuiflora (Willd. Poir, Fabaceae, were investigated by using both micronucleus test and bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100, TA102 respectively. In respect of Ames test results show that the extract does not induce mutations in any strains of Salmonella typhimurium tested since the mutagenicity index is less than 2. In the antimutagenic effect was observed that the extract at the concentrations tested significantly decreased the mutagenicity index of all strains tested which characterized the extract as antimutagenic in these conditions. In the micronucleus test in vivo, we observed that the concentrations used did not induce an increase in the frequency of micronucleus in normochromatic erythrocytes of mice. Therefore, we concluded that the extract of M. tenuiflora is not mutagenic in the absence of exogenous metabolizing system and does not induce an increase in the frequency of the micronucleus characterized as an agent not mutagenic in these conditions. Further studies of toxicity need to be made to the use of this plant in the treatment of diseases to be stimulated.

A comparison of mutagen production in fried ground chicken and beef: effect of supplemental creatine.

Science.gov (United States)

Knize, M G; Shen, N H; Felton, J S

1988-11-01

Ground chicken breast and ground beef with either endogenous or a 10-fold increase in the concentration of creatine were fried at 220 degrees C for 10 min per side. One patty (100 g) of chicken meat yielded 120,000 Salmonella (TA1538) revertants following metabolic activation. The pan residues had 39% of the total activity. Added creatine (10-fold the endogenous level) increased mutagen yields an average of 2-fold. Beef cooked under identical conditions yielded 150,000 revertants/100 g for the meat patties and pan residues combined. Added creatine to beef prior to cooking increased mutagen yields 3-fold. The mutagenic profiles following initial HPLC separation showed that chicken samples with endogenous or added creatine were remarkably similar. Chicken and beef HPLC mutagenicity profiles were also similar to each other, but not identical. This suggests that the general mutagen-forming reactions with the two different types of muscle are qualitatively similar with only minor quantitative differences. The pan residues from both meat types with and without added creatine showed some significant differences in the mutagen peak profile. This work suggests that the types of mutagens formed in chicken are similar to those formed in beef and that creatine appears to be involved in the formation of all the mutagenic compounds produced from fried muscle tissue.

Mutagenicity of food-derived carcinogens and the effect of antioxidant vitamins.

Science.gov (United States)

Montgomery, Beverly A; Murphy, Jessica; Chen, James J; Desai, Varsha G; McGarrity, Lynda; Morris, Suzanne M; Casciano, Daniel A; Aidoo, Anane

2002-01-01

The food-derived heterocyclic amines (HCAs) 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) are mutagenic in the Ames test and produce tumors in laboratory animals, including monkeys. These HCAs have also been shown to induce gene mutations in vivo. To assess the antimutagenic effects of dietary antioxidant vitamins, beta-carotene, ascorbic acid (vitamin C), and alpha-tocopherol (vitamin E), on food-borne mutagenes/carcinogens, we evaluated the mutagenic activity of the compounds alone or combined with antioxidant vitamins. We utilized the rat lymphocyte mutation assay at the hypoxanthine guanine phosphoribosyl transferase (Hprt) locus. Female Fischer 344 rats treated with different doses (0, 2.5, 5.0, 25.0, and 50.0 mg/kg) of the carcinogens were sacrificed 5 wk after mutagen treatment. Although IQ and MeIQ slightly increased mutation frequency (MF) at some doses, a significant (P carcinogen metabolism would be affected by ingestion of vitamins. The activities of endogenous detoxification enzymes, glutathione S-transferase and glutathione peroxidase (GPx), were thus examined. Intake of beta-carotene and vitamin C without the carcinogen resulted in an increase (P food or taken as supplements could, in part, counteract such mutagenic activities.

Modulation of mutagen-induced biological effects by inhibitors of DNA repair

International Nuclear Information System (INIS)

Natarajan, A.T.; Mullenders, L.F.H.; Zwanenburg, T.S.B.

1986-01-01

When lesions are induced in the DNA by mutagenic agents, they are subjected to cellular repair. Unrepaired and misrepaired lesions lead to biological effects, such as cell killing, point mutations and chromosomal alterations (aberrations and sister chromatid exchanges - SCEs). It is very difficult to directly correlate any particular type of lesion to a specific biological effect. However, in specific cases, this has been done. For example, short wave UV induced biological effects (cell killing, chromosomal alterations) result predominantly from induced cyclobutane dimers and by photoreactivation experiments, one can demonstrate that with the removal of dimers all types biological effects are diminished. In cases where many types of lesions are considered responsible for the observed biological effects other strategies have been employed to identify the possible lesion. The frequencies of induced chromosomal alterations and point mutations increase with the dose of the mutagen employed and an inhibition of DNA repair following treatment with the mutagen. Prevention of the cells from dividing following mutagen treatment allows them to repair premutational damage, thus reducing the biological effects induced. By comprehensive studies involving quantification of primary DNA lesions, their repair and biological effects will enable us to understand to some extent the complex processes involved in the manifestation of specific biological effects that follow the treatment of cells with mutagenic carcinogens

Evaluation of Quantitative Exposure Assessment Method for Nanomaterials in Mixed Dust Environments: Application in Tire Manufacturing Facilities.

Science.gov (United States)

Kreider, Marisa L; Cyrs, William D; Tosiano, Melissa A; Panko, Julie M

2015-11-01

Current recommendations for nanomaterial-specific exposure assessment require adaptation in order to be applied to complicated manufacturing settings, where a variety of particle types may contribute to the potential exposure. The purpose of this work was to evaluate a method that would allow for exposure assessment of nanostructured materials by chemical composition and size in a mixed dust setting, using carbon black (CB) and amorphous silica (AS) from tire manufacturing as an example. This method combined air sampling with a low pressure cascade impactor with analysis of elemental composition by size to quantitatively assess potential exposures in the workplace. This method was first pilot-tested in one tire manufacturing facility; air samples were collected with a Dekati Low Pressure Impactor (DLPI) during mixing where either CB or AS were used as the primary filler. Air samples were analyzed via scanning transmission electron microscopy (STEM) coupled with energy dispersive spectroscopy (EDS) to identify what fraction of particles were CB, AS, or 'other'. From this pilot study, it was determined that ~95% of all nanoscale particles were identified as CB or AS. Subsequent samples were collected with the Dekati Electrical Low Pressure Impactor (ELPI) at two tire manufacturing facilities and analyzed using the same methodology to quantify exposure to these materials. This analysis confirmed that CB and AS were the predominant nanoscale particle types in the mixing area at both facilities. Air concentrations of CB and AS ranged from ~8900 to 77600 and 400 to 22200 particles cm(-3), respectively. This method offers the potential to provide quantitative estimates of worker exposure to nanoparticles of specific materials in a mixed dust environment. With pending development of occupational exposure limits for nanomaterials, this methodology will allow occupational health and safety practitioners to estimate worker exposures to specific materials, even in scenarios

Some aspects of the combined mutagenic utilization of ionizing radiation and chemical mutagens in the experimental mutagenesis with Chlorella vulgaris B

International Nuclear Information System (INIS)

Mekhandzhiev, A.D.; Chankova, S.G.; Petkova, S.D.

1979-01-01

The influence of mutagen dose and cell cycle phase in combined mutagenic effects of ionizing radiation and EMS was experimentally studied on Chlorella vulgaris B. The duration of the cell cycle phases was determined from autoradiographic data on the kinetics of the incorporated labelled precursor ( 3 H-thymidine). The mutagenic effect was evaluated on the 10th or 11th day by the induced pigment mutations on a total of 450,105 colonies. It was found that the combining of 2, 6 or 15 krad gamma rays with EMC in doses 0.002, 0.125 or 0.5 M on the 4th, 12th, 11th, 16th or 18th hour of the cell cycle has a different effect, depending on mutagen dose and cell cycle phase. In this way, combining three different doses of gamma rays with 0.5 M EMC(LDsub(90-99)) at the onset of G 1 induces a distinct rise in the percentage of pigment mutations, as compared to the theoretically expected. The superadditive effect in this case however was associated with limitation of the mutation spectrum. Treatment with average lethal combination (6 krad gamma rays + 0.002 M EMC or 6 krad gamma rays + 0.125 M EMC) was not very effective, but the induced mutations had a rather broader spectrum (8-9 types). A comparison of the theoretically expected yield of pigment mutations with the actually obtained one shows a superadditibility only in cells treated in G 1 (LD 60 ) and in the mid S-phase (LD 40 ). (A.B.)

Sampling and preparation method for mutagenicity test of exhaust gas from municipal waste incinerator; Haikibutsu shokyakuro hai gas no hen`i gensei shiken no tameno shiryo saishu/chosei hoho

Energy Technology Data Exchange (ETDEWEB)

Yoshino, H. [Kanagawa Environmental Research Center, Kanagawa (Japan); Urano, K. [Yokohama National Univ. (Japan)

1994-09-10

It is well known that many kinds of hazardous organic compounds in incinerator exhaust gases. In this study, a simple sampling method to test mutagenicity on exhaust gases in flue and its extracting and its solvent converting methods by organic solvents were examined. In sampling 100 to 300 l at about 2 l/min in aspirating speed of the extract gases, the most of mutagenic substance were collected almost completely by condensed water and qualtz wool column. And, the collected materials into the condensed water could almost perfectly recovered by extracting the condensed water with about its one fourth volume of ethylacetate on vibrating once in 5 min., extracting the quartz wool column on flowing 20 ml of ethylacetate at the speed of about 3 ml/min., and others. After mixing such effluents and dewatering with about 5 g of sodium sulfate, they are evaporated out ethylacetate and resolved with 5 ml of dimethylsulfoxide (DMSO) to execute Ames mutagenicity test. As a result, more than about 3000 net rev./Nm{sup 3} of the mutagenicity was estmated on TA 98 strain. 9 refs., 5 figs., 8 tabs.

Effect of eugenol on the genotoxicity of established mutagens in the liver

NARCIS (Netherlands)

Rompelberg, C.J.M.; Evertz, S.J.C.J.; Bruijntjes-Rozier, G.C.D.M.; Heuvel, P.D. van den; Verhagen, H.

1996-01-01

The influence of in vivo treatment with eugenol on established mutagens was studied to determine whether eugenol has antigenotoxic potential. The effects of eugenol in rats was investigated in the unscheduled DNA synthesis (UDS) assay with established mutagens and the Salmonella typhimurium

Paving asphalt products exhibit a lack of carcinogenic and mutagenic activity.

Science.gov (United States)

Goyak, Katy O; McKee, Richard H; Minsavage, Gary D; McGowan, Claude; Daughtrey, Wayne C; Freeman, James J

2011-10-01

A paving asphalt and a vacuum residuum (derived from crude oil by atmospheric and subsequent vacuum distillation and used as a blend stock for asphalt) were tested in skin carcinogenesis assays in mice and in optimized Ames assays for mutagenic activity. In the skin cancer tests, each substance was applied twice weekly for 104 weeks to the clipped backs of groups of 50 male C3H mice. Neither the paving asphalt nor the vacuum residuum (30% weight/volume and 75% weight/weight in US Pharmacopeia mineral oil, respectively) produced any tumors. The positive control benzo[a]pyrene (0.05% w/v in toluene) induced tumors in 46 of 50 mice, demonstrating the effectiveness of the test method. Salmonella typhimurium tester strain TA98 was used in the optimized Ames assay to evaluate mutagenic potential. Dimethylsulfoxide (DMSO) extractions of the substances were not mutagenic when tested up to toxic limits. Thus, under the conditions of these studies, neither the paving asphalt nor the vacuum residuum was carcinogenic or mutagenic.

Evaluation of acute and subacute toxicity and mutagenic activity of the aqueous extract of pecan shells [Carya illinoinensis (Wangenh.) K. Koch].

Science.gov (United States)

Porto, Luiz Carlos Santos; da Silva, Juliana; Ferraz, Alexandre de Barros Falcão; Corrêa, Dione Silva; dos Santos, Marcela Silva; Porto, Caroline Dalla Lana; Picada, Jaqueline Nascimento

2013-09-01

The infusion of pecan shells has been used to prevent and control hypercholesterolemia, diabetes and toxicological diseases. The aim of the present study was to evaluate toxicity and mutagenic effects of pecan shells aqueous extract (PSAE). Wistar rats were treated with a single dose of 300 or 2000 mg/kg of PSAE in the acute toxicity test. For the subacute test, the animals received 10 or 100 mg/kg of PSAE for 28 days. The mutagenicity was evaluated using Salmonella/microsome assay in TA1535, TA1537, TA98, TA100 and TA102 S. typhimurium strains in the presence and absence of metabolic activation (S9 mix) and micronucleus test in bone marrow. HPLC analyses indicated the presence of tannins, flavonoids, gallic and ellagic acids. Except for triglycerides, all treated groups presented normal hematological and biochemical parameters. Lower levels of triglycerides and weight loss were observed in the 100 mg/kg group. Mutagenic activities were not detected in S. typhimurium strains and by the micronucleus test. Based on these results, PSAE was not able to induce chromosomal or point mutations, under the conditions tested. The 100mg/kg dose showed significant antihyperlipidemic action, with no severe toxic effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mutagenic effectiveness and efficiency of EMS, sodium azide and gamma radiation in chickpea (Cicer arietinum L.)

International Nuclear Information System (INIS)

Barshile, J.D.; Apparao, B.J.

2006-01-01

Mutagenic effectiveness and efficiency of Ethyl Methane Sulphonate (EMS), Sodium Azide (SA) and gamma radiation on two cultivars of chickpea (Cicer arietinum L), Vijay and Vishwas were evaluated by the biological damages caused by them in M 1 generation and on the basis of frequency of chlorophyll mutations produced in the M 2 generation. All mutagenic treatments of EMS, SA and gamma radiation decreased germination, seedling height, plant survival and pollen fertility in both the cultivars. The extent of effect was dose dependent. LD 50 values of mutagen were found to be helpful for planning experimental mutagenesis in chickpea. Frequency of chlorophyll mutations in M 2 generation was less in Vijay as compared to Vishwas. Mutagenic effectiveness is inversely proportional to the increasing concentrations/doses of mutagens in both the cultivars, except for gamma radiation treatments in the cultivar Vishwas. All three mutagens (except EMS in the Vijay and gamma radiation in the cultivar Vishwas) exhibited gradual decrease in mutagenic efficiency, with an increase in their concentration/dose. (author)

Potential Dermal Exposure in greenhouses for manual sprayers: Analysis of the mix/load, application and re-entry stages

Energy Technology Data Exchange (ETDEWEB)

Ramos, Laura M.; Querejeta, Giselle A.; Flores, Andrea P.; Hughes, Enrique A.; Zalts, Anita [Instituto de Ciencias, Universidad Nacional de General Sarmiento (UNGS), J. M. Gutierrez 1150, (B1613GSX) Los Polvorines, Prov. de Buenos Aires (Argentina); Montserrat, Javier M., E-mail: jmontser@ungs.edu.ar [Instituto de Ciencias, Universidad Nacional de General Sarmiento (UNGS), J. M. Gutierrez 1150, (B1613GSX) Los Polvorines, Prov. de Buenos Aires (Argentina); Instituto de Investigaciones en Ingenieria Genetica y Biologia Molecular (CONICET), Vuelta de Obligado 2490, 2o piso, Buenos Aires (Argentina)

2010-09-01

An evaluation of the Potential Dermal Exposure for the mix/load, application and re-entry stages, associated with procymidone and deltamethrin usage, was carried out for tomatoes grown in greenhouses of small production units in Argentina. Eight experiments were done with four different operators, under typical field conditions with a lever operated backpack sprayer. The methodology applied was based on the Whole Body Dosimetry technique, evaluating a set of different data for the mix and load, application and re-entry operations. These results indicated that the Potential Dermal Exposure of the application step was (38 {+-} 17) mL h{sup -1} with the highest proportion on torso, head and arms. When the three stages were compared, re-entry was found to contribute least towards the total Potential Dermal Exposure; meanwhile in all cases, except one, the mix/load operation was the stage with highest exposure. The Margin of Safety for each different operation was also calculated and the proportion of pesticide drift from the greenhouse to the environment is presented. These results emphasize the importance of improving the personal protection measures in the mix and load stage, an operation that is not usually associated with high-risk in small production units.

Potential Dermal Exposure in greenhouses for manual sprayers: Analysis of the mix/load, application and re-entry stages

International Nuclear Information System (INIS)

Ramos, Laura M.; Querejeta, Giselle A.; Flores, Andrea P.; Hughes, Enrique A.; Zalts, Anita; Montserrat, Javier M.

2010-01-01

An evaluation of the Potential Dermal Exposure for the mix/load, application and re-entry stages, associated with procymidone and deltamethrin usage, was carried out for tomatoes grown in greenhouses of small production units in Argentina. Eight experiments were done with four different operators, under typical field conditions with a lever operated backpack sprayer. The methodology applied was based on the Whole Body Dosimetry technique, evaluating a set of different data for the mix and load, application and re-entry operations. These results indicated that the Potential Dermal Exposure of the application step was (38 ± 17) mL h -1 with the highest proportion on torso, head and arms. When the three stages were compared, re-entry was found to contribute least towards the total Potential Dermal Exposure; meanwhile in all cases, except one, the mix/load operation was the stage with highest exposure. The Margin of Safety for each different operation was also calculated and the proportion of pesticide drift from the greenhouse to the environment is presented. These results emphasize the importance of improving the personal protection measures in the mix and load stage, an operation that is not usually associated with high-risk in small production units.

Mutagenic effect of ionizing radiation and chemical and environmental agents in Tradescantia

International Nuclear Information System (INIS)

Cebulska-Wasilewska, A.

1988-01-01

The studies covered the following problems: an influence of some environmental agents on the mutagenic effectiveness of ionizing radiation, interaction between ionizing radiation and chemical mutagens in the induction of somatic mutations and also an application of Tradescantia model system for biological monitoring. The studies showed that the pretreatment of Tradescantia plants with sodium fluoride or the modification of the soil composition with dolomite admixture, visibly influences plants radiosensitivity. The analysis of the changes in the dose-response curves suggested that the employed agents were influencing in different ways the repair processes of the DNA. The studies on the interaction between agents proved that the synergistic effect occurs in case of combined action of ionizing radiation with such chemical mutagens as ethyl methansulfonate or 1,2 dibromomethane. It was also discovered that in the range of low doses the effect was proportional to radiation dose and total exposition to chemical mutagen. The field application of Tradescantia method defined the mutagenicity of air pollution in the Cracow area. The highest frequencies of mutations were detected after the Chernobyl accident and after the damage of the filters in the Pharmaceutical Plant. The applied method was evaluated in respect of its usefulness for biological monitoring of environmental pollution. 163 refs. (author)

Mutagenic activity of N-nitrosoethylene urea in higher plants. [C. cappilaris L

Energy Technology Data Exchange (ETDEWEB)

Sal' nikova, T.V.; Grigorova, N.V.; Laputin, D.L.; Shustova, L.L., Zazimko, V.V.; Shustov, G.V.; Kostyanovskiy, R.G.

1984-04-01

Cytopathogenetic effect of N-nitrosoethylene urea (NETM) on common wheat and C. cappilaris L. are studied. Air-dried wheat seeds were treated with 1 of 5 concentrations (0.1-0.01%) of NETM for 18 hours at pH 5.7 or 7.0. Treatment of seeds with NETM reduced the germinating power significantly at pH 5.7, especially at high concentrations of NETM. NETM is also a highly effective chemical mutagen. Maximum mutagenic effect appears at pH 7.0. NETM greatly reduced mitotic activity of wheat and C. cappilaris L. which is typical for alkylating type mutagens. The aberration rate is rather high for both objects studied. In both the anaphase and metaphase method of calculating chromosomal injuries, a great percentage of the total number of aberrations are chromatid type reconstructions which indicates predominance of the alkylating action of NETM. Wheat affected by NETM has a large number of anaphase cells with lagging chromosome which is atypical for alkylating type mutagens. This may be explained by the effect of NETM on centromeric and precentromeric parts of chromosomes and spindle filaments. NETM is an alkylating agent rather than a carbamoylating agent. It is a highly active and slightly toxic mutagen. 25 references, 1 figure.

Induction of bacterial antibiotic resistance by mutagenic halogenated nitrogenous disinfection byproducts

International Nuclear Information System (INIS)

Lv, Lu; Yu, Xin; Xu, Qian; Ye, Chengsong

2015-01-01

Halogenated nitrogenous disinfection byproducts (N-DBPs) raise concerns regarding their mutagenicity and carcinogenicity threatening public health. However, environmental consequence of their mutagenicity has received less attention. In this study, the effect of halogenated N-DBPs on bacterial antibiotic resistance (BAR) was investigated. After exposure to bromoacetamide (BAcAm), trichloroacetonitrile (TCAN) or tribromonitromethane (TBNM), the resistance of Pseudomonas aeruginosa PAO1 to both individual and multiple antibiotics (ciprofloxacin, gentamicin, polymyxin B, rifampin, tetracycline, ciprofloxacin + gentamicin and ciprofloxacin + tetracycline) was increased, which was predominantly ascribed to the overexpression of efflux pumps. The mechanism of this effect was demonstrated to be mutagenesis through sequencing and analyzing antibiotic resistance genes. The same induction phenomena also appeared in Escherichia coli, suggesting this effect may be universal to waterborne pathogens. Therefore, more attention should be given to halogenated N-DBPs, as they could increase not only genotoxicological risks but also epidemiological risks of drinking water. - Highlights: • The halogenated N-DBPs could induce bacterial antibiotic resistance. • Both individual and multiple resistances could be induced. • Efflux mechanism played an important role in the induced antibiotic resistance. • The halogenated N-DBPs induced bacterial antibiotic resistance via mutagenesis. • Effects of N-DBPs on antibiotic resistance may be universal to waterborne pathogens. - Halogenated N-DBPs could increase antibiotic resistance, even multidrug resistance via mutagenesis, contributing to the enrichment of antibiotic resistant bacteria in drinking water

Mutagen induced variability in Ragi (Eleucine coracana Gaertn)

International Nuclear Information System (INIS)

Haider, Z.A.; Mahto, J.L.; Kumar, Binod

1996-01-01

Varieties A-404 and HR-374 of Ragi (Eleucine coracana Gaertn) when subjected to different doses of gamma rays, EMS and their combination treatments showed a linear reverse relationship between doses and germination percentage. The same was true for seedling survival and pollen fertility. Variety A-404 proved to be more sensitive to all mutagenic treatments as compared to the variety HR-374. There was, however, a general gain with respect to panicle length in most of the treatments, where as for a number of fingers per panicle no order could be observed in any of the mutagen used. (author). 10 refs., 2 tabs

DNA repair in mutagen-injured higher plants

International Nuclear Information System (INIS)

Veleminsky, J.; Gichner, T.

1978-01-01

Data are summarized proving the occurrence of photoreactivation of UV-induced pyrimidine dimers in cells of Nicotiana tabucum, Gingko and carrot, the excision of dimers in cells of Nicotiana tabacum, Gingko and carrot, the excision of dimers in protoplasts of carrot and in embryos of Lathyrus sativus, and the repair of DNA single-strand breaks induced in carrot protoplasts and barley embryonic cells by ionizing radiation. In irradiated barley embryos the unscheduled DNA synthesis and higher accessibility of induced primers to DNA polymerase I of E. coli were observed preferentially in G 1 cells with diffused chromatin. These reactions were inhibited by caffeine and EDTA. Unscheduled DNA synthesis was also observed in synchronized irradiated root cuttings of Vicia faba and in barley embryos treated with 4-nitroquinoline oxide, the latter being inhibited by caffeine and hydroxyurea. Repair synthesis was also established in barley embryos treated with mutagenic N-methyl-N-nitrosourea under conditions that postponed the onset of germination after the treatment. The same conditions enhanced the repair of DNA single-strand breaks induced by this mutagen and several other monofunctional alkylating compounds. From tissues of barley and of Phaseolus multiflorus, endonucleases for apurinic sites were isolated and characterized. Some of them are located in chromatin, others in chloroplasts. The relation between DNA repair and genetic effects of mutagens in higher plants is also discussed. (Auth.)

Exposure to aerosol and gaseous pollutants in a room ventilated with mixing air distribution

DEFF Research Database (Denmark)

Bivolarova, Mariya Petrova; Ondráček, Jakub; Ždímal, Vladimír

2016-01-01

The present study investigates the aerosol and gas dispersal in a mechanically ventilated room and the personal exposure to these contaminants. The study was performed in a full-scale climate chamber. The room was air conditioned via mixing total volume ventilation system. The room occupancy was ...... of the thermal manikin were measured. The results showed higher exposure to the contaminants measured at the breathing zone than at the ambient air. The behaviour of the tracer gas and the aerosols was similar.......The present study investigates the aerosol and gas dispersal in a mechanically ventilated room and the personal exposure to these contaminants. The study was performed in a full-scale climate chamber. The room was air conditioned via mixing total volume ventilation system. The room occupancy...... was simulated by a sitting dressed thermal manikin with realistic body shape. During the experiments monodisperse aerosols of three sizes and nitrous oxide tracer gas were generated simultaneously from one location in the room. The aerosol and gas concentrations in the bulk room air and in the breathing zone...

Scanning electron-microscopic and X-ray-microanalytic observation of diesel-emission particles associated with mutagenicity

International Nuclear Information System (INIS)

Nakashima, K.; Yoshitsugu, K.; Tokiwa, H.; Fukuoka Environmental Research Center

1983-01-01

The particles formed by diesel combustion, which may contain various mutagenic chemicals like polycyclic aromatic hydrocarbons (PAH), are analyzed in their morphology by scanning electron microscopy; their sulfur content is detected by X-ray microanalysis, and mutagenicity is tested with a Salmonella typhimurium bioassay. The authors find a close correlation between sulfur content and mutagenicity of PAH. (Auth.)

A Perceptual Pathway to Bias: Interracial Exposure Reduces Abrupt Shifts in Real-Time Race Perception That Predict Mixed-Race Bias.

Science.gov (United States)

Freeman, Jonathan B; Pauker, Kristin; Sanchez, Diana T

2016-04-01

In two national samples, we examined the influence of interracial exposure in one's local environment on the dynamic process underlying race perception and its evaluative consequences. Using a mouse-tracking paradigm, we found in Study 1 that White individuals with low interracial exposure exhibited a unique effect of abrupt, unstable White-Black category shifting during real-time perception of mixed-race faces, consistent with predictions from a neural-dynamic model of social categorization and computational simulations. In Study 2, this shifting effect was replicated and shown to predict a trust bias against mixed-race individuals and to mediate the effect of low interracial exposure on that trust bias. Taken together, the findings demonstrate that interracial exposure shapes the dynamics through which racial categories activate and resolve during real-time perceptions, and these initial perceptual dynamics, in turn, may help drive evaluative biases against mixed-race individuals. Thus, lower-level perceptual aspects of encounters with racial ambiguity may serve as a foundation for mixed-race prejudice. © The Author(s) 2016.

In vitro mutagenicity and genotoxicity study of 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene, using the micronucleus test and the alkaline single cell gel electrophoresis technique (comet assay) in human lymphocytes.

Science.gov (United States)

Tafazoli, M; Kirsch-Volders, M

1996-12-20

The main objective of this study was to compare the cytotoxic genotoxic and mutagenic activity of a number of chlorinated aliphatic hydrocarbons, which are widely used as chemical intermediates, solvents, degreasing agents etc. in industry, and to establish the structure-toxicity relationship of the chemicals by using the most adequate determinants in estimating their toxicity. The mutagenicity and cytotoxicity of some of the candidate chemicals, namely 1,2-dichloroethylene, 1,1,2-trichloroethane, 1,3-dichloropropane, 1,2,3-trichloropropane and 1,1,3-trichloropropene were evaluated in an in vitro micronucleus assay. The cytokinesis-block methodology was applied on human lymphocytes in the presence or absence of an external metabolic activation system (S9-mix). In the micronucleus assay, all test substances, except 1,2,3-trichloropropane with and without S9-mix and 1,1,2-trichloroethane without S9-mix in the repeated experiment, exhibited a low but statistically significant mutagenic activity, compared to the concurrent control. However, none of the five chemicals was able to induce a clear and reproducible linear dose-dependent increase in micronucleus frequencies in this assay. Generally, mutagenic activity of the chemicals was found in the absence of severe cytotoxicity and/or cell cycle delay. The DNA breakage capacity and the cytotoxicity of these chemicals were also assessed in the alkaline single cell gel (SCG) electrophoresis test (comet assay) with and without S9-mix in isolated human lymphocytes. All chemical compounds induced DNA breakage, in the presence or absence of the metabolic activation system, at the doses tested. The data showed that the DNA reactivity of the chemicals increased with increasing degree of halogenation. The results of the present work suggested that the comet assay might be a more suitable and sensitive screening method than the micronucleus test for this particular class of compound. However, both assays do detect different

The Role of Genotypes That Modify the Toxicity of Chemical Mutagens in the Risk for Myeloproliferative Neoplasms

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Carol Ann Gross-Davis

2015-02-01

Full Text Available Background: The etiology of myeloproliferative neoplasms (MPN (polycythemia vera; essential thrombocythemia; primary myelofibrosis is unknown, however they are associated with a somatic mutation—JAK2 V617F—suggesting a potential role for environmental mutagens. Methods: We conducted a population-based case-control study in three rural Pennsylvania counties of persons born 1921–1968 and residing in the area between 2000–2008. Twenty seven MPN cases and 292 controls were recruited through random digit dialing. Subjects were genotyped and odds ratios estimated for a select set of polymorphisms in environmentally sensitive genes that might implicate specific environmental mutagens if found to be associated with a disease. Results: The presence of NAT2 slow acetylator genotype, and CYP1A2, GSTA1, and GSTM3 variants were associated with an average 3–5 fold increased risk. Conclusions: Exposures, such as to aromatic compounds, whose toxicity is modified by genotypes associated with outcome in our analysis may play a role in the environmental etiology of MPNs.

The effect of γ-radiation on smoked fish using short-term mutagenicity assays

International Nuclear Information System (INIS)

Dela Rosa, A.M.; Banzon, R.B.

1989-01-01

The effect of γ-radiation on the mutagenicity potential of wood-smoked fish was investigated. Smoked fish were irradiated with radiation doses of 2.0, 4.0, 6.0 and 8.0 kGy. The DMSO extracts of non-radiated and irradiated smoked fish were tested for mutagenicity using the Ames plate incorporation assay, host-mediated assay, and the micronucleus test. It was observed that γ-irradiation did not induce any significant increase in the number of revertants of TA98, TA100 and TA104 as compared with the non-radiated smoked fish. Results of the host-mediated assay and the micronucleus test showed no difference in the mutagenic response of non-radiated in irradiated smoked fish. The results indicate thet γ-radiation does not introduce mutagens in smoked fish. (author). 17 refs.; 6 tabs

Antimutagenic properties of lactic acid-cultured milk on chemical and fecal mutagens

Energy Technology Data Exchange (ETDEWEB)

Hosono, A.; Kashina, T.; Kada, T.

1986-09-01

The antimutagenic properties of milk cultured with Lactobacillus bulgaricus and Streptococcus thermophilus were examined using streptomycin-dependent strains of Salmonella in an in vitro assay system. The mutagens utilized for testing included 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide, 4-nitroquinoline-N-oxide, and fecal mutagenic extracts from cats, monkeys, dogs and other mammals. Both types of cultured milk exhibited antimutagenic activity on all mutagens used. Antimutagenic activities of the cultured milks with 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide and 4-nitroquinoline-N-oxide increased with incubation time but were thermolabile beyond 55/sup 0/C for 10 min.

Responses of physiological and biochemical components in Gossypium hirsutum L. to mutagens

International Nuclear Information System (INIS)

Muthusamy, A.; Vasanth, K.; Jayabalan, N.

2003-01-01

The two tetraploid varieties of cotton were exposed to gamma rays, EMS and SA. Chlorophyll, carotenoids, sugar, starch, free amino acids, protein, lipids, DNA and RNA were estimated quantitatively. All the physiological and biochemical components were increased in lower dose/concentration of the mutagenic treatments and they were decreased in higher dose/concentrations. The stimulation of the biochemical contents was a dose/concentration dependent response. Among the two varieties, MCU 11 was found to be responsive to mutagens than MCU 5. Based on the study the lower dose/concentration of the mutagenic treatments could enhance the biochemical components which is used for improved economic characters of cotton. (author)

Protection against UV-induced toxicity and lack of mutagenicity of Antarctic Sanionia uncinata

International Nuclear Information System (INIS)

Fernandes, A.S; Mazzei, J.L; Oliveira, C.G; Evangelista, H.; Marques, M.R.C.; Ferraz, E.R.A.; Felzenszwalb, I.

2017-01-01

Antarctica moss Sanionia uncinata (Hedw.) Loeske is exposed in situ to damaging levels of ultraviolet (UV) radiation. This moss has the ability to respond to UV radiation exposure producing secondary metabolites such as flavonoids, and has been recommended as a potential source of photoprotective compounds and antioxidants. The aim of the present paper was to investigate the free-radical scavenging activity and mutagenic and photomutagenic properties of methanolic (ME), hydroethanolic (HE) and ethanolic (EE) extracts of S. uncinata. The phenolic contents were evaluated by high-performance liquid chromatography (HPLC) and spectrophotometry. The findings showed that ME and EE presented the highest phenolic contents and inhibited free radical-scavenging activity against 2,2′-diphenyl-1 picrylhydrazyl (DPPH) and the HPLC analysis indicated several classes of phenolic acids and flavonoids. The sun protection factors (SPF) were determined by an in vitro method and the results showed significant values. The SPF values of BZ-3 at 50 μg/mL increased significantly in association with ME, HE and EE. The extracts did not induce mutagenicity in auxotrophic Salmonella typhimurium histidine and photomutagenicity was not detected in the TA102 and TA104 strains after exposure to UV-A at doses of up to 6.5 J/cm 2 for the TA102 strain and up to 0.24 J/cm 2 for the TA104 strain. In addition, with the exception of ME, all the extracts induced photoprotective effects in the presence of the TA104 strain at 0.04 J/cm 2 . The present results suggest that S. uncinata extracts did not induce photomutation and showed promise for photoprotection against the photobiological and ROS-inducing effects of the UV-A radiation.

The effect of Aspergillus niger mutagenization on citric acid biosynthesis

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Stanisław Walisch

2014-08-01

Full Text Available The industrial A. niger strain producing citric acid was mutagenized with the use of new chemical mutagens: free nitroxyl radicals. Strains of higher citric acid production yield were obtained. Citric acid was produced in a shorter time compared to the initial strain. During 6-12 months of storage most of the strains preserved their positive features which proves that mutants with profitable biotechnological properties were obtained. These mutants are used in industrial process.

Mutagenic effect of cyclophosphan on bone marrow cells of irradiated rats

International Nuclear Information System (INIS)

Barkan, R.S.; Yakovleva, T.K.

1979-01-01

The frequency of chromosome aberrations in bone marrow cells of male rats was studied 24 hours after the intraperitoneal injection of cyclophosphane (25 mg/kg weight). Cyclophosphane (CP) was injected to animals that had been earlier (15 days before, 1, 3, 4, 6 and 9 months earlier) exposed to X-ray and γ-irradiation at the dose of 400 rad. It has been shown that the preliminary irradiation of animals results in a higher mutagenic CP effect as against its effect for non irradiated rats. The effect was recorded during four months following the acute single x-irradiation (dose rate of 70 rad/min) and within one month following chronic γ-irradiation (dose rate of 100 rad/day). At later periods, the above effect fully disappeared. Chronic irradiation was less effective with regard to the subsequent mutagenic CP action than the acute irradiation. In most experiments with acute irradiation an increase in mutagenic CP efficiency revealed itself both in an increase in the frequency of cells with chromosome aberrations and in the cell damage rate. The possible mechanisms of the effect of preliminary irradiation on the subsequent mutagenic effect of chemical compounds are discussed

Absence of mutagenicity of plants used to treat gastrointestinal disorders

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Santos F.V.

2013-01-01

Full Text Available The Brazilian Savanna (locally called “Cerrado” is an important biome presenting several plants that are used in popular medicine. However, the risks associated with the consumption of derivatives from these plants are generally unknown. Studies with compounds obtained from different species have shown the risks of DNA damage. The present work assessed the in vivo mutagenicity of three plant species used in popular medicine to treat human gastrointestinal disorders (Mouriri pusa, Qualea grandiflora and Qualea multiflora. The micronucleus assay was performed in peripheral blood of mice submitted to acute treatments. Results showed that no assessed extracts were mutagenic in vivo. In fact, the absence of mutagenicity in the present study indicates that the extracts do not contain compounds capable of inducing DNA breaks or chromosomal loss. However, further analysis should be performed in others systems to guarantee their safety, mainly to human chronic use.

Survey of the mutagenicity of surface water, sediments, and drinking water from the Penobscot Indian Nation.

Science.gov (United States)

Warren, Sarah H; Claxton, Larry D; Diliberto, Janet; Hughes, Thomas J; Swank, Adam; Kusnierz, Daniel H; Marshall, Valerie; DeMarini, David M

2015-02-01

U.S. Environmental Protection Agency (US EPA) Regional Applied Research Effort (RARE) projects address the effects of environmental pollutants in a particular region on the health of the population in that region. This report is part of a RARE project that addresses this for the Penobscot Indian Nation (PIN), Penobscot Island, Maine, U.S., where the Penobscot River has had fish advisories for many years due to high levels of mercury. We used the Salmonella mutagenicity assay with strains TA100, TA98, YG1041, and YG1042 with and without metabolic activation to assess the mutagenic potencies of organic extracts of the Penobscot River water and sediment, as well as drinking-water samples, all collected by the PIN Department of Natural Resources. The source water for the PIN drinking water is gravel-packed groundwater wells adjacent to the Penobscot River. Most samples of all extracts were either not mutagenic or had low to moderate mutagenic potencies. The average mutagenic potencies (revertants/L-equivalent) were 337 for the drinking-water extracts and 177 for the river-water extracts; the average mutagenic potency for the river-sediment extracts was 244 revertants(g-equivalent)(-1). This part of the RARE project showed that extracts of the Penobscot River water and sediments and Penobscot drinking water have little to no mutagenic activity that might be due to the classes of compounds that the Salmonella mutagenicity assay detects, such as polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (nitroarenes), and aromatic amines. This study is the first to examine the mutagenicity of environmental samples from a tribal nation in the U.S. Published by Elsevier Ltd.

Distinguishing potential sources of genotoxic exposure via HPRT mutations

International Nuclear Information System (INIS)

Molholt, B.; Finette, B.A.

2000-01-01

T-cell HPRT (hypoxanthine phosphoribosyltransferase) mutations were used to monitor to environmental mutagens in children who have developed cancer at a persistently high rate in Toms River, New Jersey, USA. A preliminary epidemiological study has found a statistically-significant association between drinking public water (by pregnant mother or infant) and subsequent risk for childhood cancer. Three potential sources of mutagenic exposures in Toms River may have increased the rate of carcinogenic initiation significantly in children: 1. Benzidine-based, other azo-dye and anthraquinone dye wastes released by Ciba-Geigy enterprise; 2. Plastic wastes of Union Carbide enterprise; 3. Radium-224, present in unusually high concentrations in the Cohansey aquifer. Specific patterns of HPRT mutations are utilized to distinguish these various potential sources of carcinogenic exposures in the drinking water of families with childhood cancer and to differentiate chemically or radiologically induced cancers from those which occur spontaneously [ru

Mutagenicity of γ-irradiated oxygenated and deoxygenated solutions of 2-deoxy-D-ribose and D-ribose in Salmonella typhimurium

International Nuclear Information System (INIS)

Wilmer, J.; Leveling, H.; Schubert, J.

1981-01-01

Solutions of 2-deoxy-D-ribose and D-ribose were γ-irradiated under different experimental conditions and tested for mutagenicity, with and without preincubation, in Salmonella typhimurium. The irradiated sugar solutions were mutagenic in the tester strains TA 100 and TA 98. Except for malonaldehyde (MDA), which is not mutagenic in the concentrations produced radiolytically, the relative mutagenicities of the individual radiolytic products are unknown. With irradiated solutions of 2-deoxy-D-ribose, a relationship was found between the level of non-MDA aldehydes and the mutagenicity in TA 100. Heating the irradiated solutions of 2-deoxy-D-ribose resulted in a temperature-dependent reduction fo the mutagenicity. Autoclaved, non-irradiated solutions of 2-deoxy-D-ribose were not mutagenic in the Salmonella test. (orig.)

Carcinogen biomonitoring in human exposures and laboratory research: validation and application to human occupational exposures.

Science.gov (United States)

Talaska, Glenn; Maier, Andrew; Henn, Scott; Booth-Jones, Angela; Tsuneoka, Yutaka; Vermeulen, Roel; Schumann, Brenda L

2002-08-05

A multiple biomarker approach is required to integrate for metabolism, temporal response and exposure-response kinetics, biological relevance, and positive predictive value. Carcinogen DNA adduct analysis can be used in animal and in vitro studies to detect absorption permutations caused by mixture interactions, and to control metabolic variation when specific CYP450 genes (1A1 or 1A2) are knocked out. These enzymes are not critical to the metabolic activation of model Polycyclic Aromatic Compounds (PAC) and aromatic amines, respectively, as suggested by in vitro analysis. Several human studies have been carried out where multiple biomarkers have been measured. In a study of benzidine workers, the similarities in elimination kinetics between urinary metabolites and mutagenicity is likely responsible for a better correlation between these markers than to BZ-DNA adducts in exfoliated cells. In a study of rubber workers, the relationship between specific departments, urinary 1 HP and DNA adducts in exfoliated cells coincided with the historical urinary bladder cancer risk in these departments; the same relationship did not hold for urinary mutagenicity. In a study of automotive mechanics, biomarkers were used to monitor the effectiveness of exposure interventions. These data reinforce the notion that carcinogen biomarkers are useful to monitor exposure, but that a complementary approaches involving effect and perhaps susceptibility biomarkers is necessary to obtain the necessary information.

[Mutagenic effect of the food-coloring agents tartrazine and indigo carmine].

Science.gov (United States)

Karpliuk, I A; Volkova, N A; Okuneva, L A; Gogol', A T; Rybakova, K D

1984-01-01

The authors studied the mutagenic action of the food dyes, tartrazine (both Soviet and imported) and indigocarmine in a microbial model and in warm-blooded animals (linear mice). Determined the toxicity and mutagenic action of the dyes on E. coli, strain K-12, carried out chromosomal analysis of the bone marrow, examined the dominant lethals in CBA X C57BL/6 mice. The recommended daily dose amounts to 400 mg/kg for tartrazine and to 50 mg/kg for indigocarmine with regard to the safety factor equal to 100. The data derived as a result of studying the mutagenic activity of tartrazine manufactured in the USSR and CSSR and indigocarmine paste in 3 experimental models allow the conclusion to be made that the doses of these dyes applied in food industry are fairly safe.

DNA replication after mutagenic treatment in Hordeum vulgare.

Science.gov (United States)

Kwasniewska, Jolanta; Kus, Arita; Swoboda, Monika; Braszewska-Zalewska, Agnieszka

2016-12-01

The temporal and spatial properties of DNA replication in plants related to DNA damage and mutagenesis is poorly understood. Experiments were carried out to explore the relationships between DNA replication, chromatin structure and DNA damage in nuclei from barley root tips. We quantitavely analysed the topological organisation of replication foci using pulse EdU labelling during the S phase and its relationship with the DNA damage induced by mutagenic treatment with maleic hydrazide (MH), nitroso-N-methyl-urea (MNU) and gamma ray. Treatment with mutagens did not change the characteristic S-phase patterns in the nuclei; however, the frequencies of the S-phase-labelled cells after treatment differed from those observed in the control cells. The analyses of DNA replication in barley nuclei were extended to the micronuclei induced by mutagens. Replication in the chromatin of the micronuclei was rare. The results of simultanous TUNEL reaction to identify cells with DNA strand breaks and the labelling of the S-phase cells with EdU revealed the possibility of DNA replication occurring in damaged nuclei. For the first time, the intensity of EdU fluorescence to study the rate of DNA replication was analysed. Copyright © 2016 Elsevier B.V. All rights reserved.

Mutagenic DNA repair in Escherichia coli. VII

International Nuclear Information System (INIS)

Bridges, B.A.; Mottershead, R.P.

1978-01-01

Incubation of E. coli WP2 in the presence of chloramphenicol (CAP) for 90 min before and 60 min after γ-irradiation had no effect on the induction of Trp + mutations. Bacteria that had been treated with CAP for 90 min prior to UV irradiation showed normal or near normal yields of induced mutations to streptomycin or colicin E2 resistance. Most of these mutations lost their photoreversibility (indicating 'fixation') during continued incubation with CAP for a further 60 min after irradiation, during which time neither protein nor DNA synthesis was detectable. It is suggested that CAP-sensitive protein synthesis is not required for mutagenic (error-prone) repair of lesions in pre-existing DNA, arguing against an inducible component in this repair. In contrast the frequency of UV-induced mutations to Trp + (largely at suppressor loci) was drastically reduced by CAP pretreatment, confirming the need for an active replication fork for UV-mutagenesis at these loci. It is known from the work of others that CAP given after UV abolishes mutagenesis at these loci. It is concluded that CAP-sensitive protein synthesis (consistent with a requirement for an inducible function) is necessary for mutagenic repair only in newly-replicated DNA (presumably at daughter strand gaps) and not in pre-existing DNA. The data are consistent with but do not prove the hypothesis that CAP-sensitive and insensitive modes of mutagenesis reflect minor differences in the operation of a single basic mutagenic repair system. (Auth.)

Mutagenicity and oxidative damage induced by an organic extract of the particulate emissions from a simulation of the deepwater horizon surface oil burns.

Science.gov (United States)

DeMarini, David M; Warren, Sarah H; Lavrich, Katelyn; Flen, Alexis; Aurell, Johanna; Mitchell, William; Greenwell, Dale; Preston, William; Schmid, Judith E; Linak, William P; Hays, Michael D; Samet, James M; Gullett, Brian K

2017-04-01

Emissions from oil fires associated with the "Deepwater Horizon" explosion and oil discharge that began on April 20, 2010 in the Gulf of Mexico were analyzed chemically to only a limited extent at the time but were shown to induce oxidative damage in vitro and in mice. To extend this work, we burned oil floating on sea water and performed extensive chemical analyses of the emissions (Gullett et al., Marine Pollut Bull, in press, ). Here, we examine the ability of a dichloromethane extract of the particulate material with an aerodynamic size ≤ 2.5 µm (PM 2.5 ) from those emissions to induce oxidative damage in human lung cells in vitro and mutagenicity in 6 strains of Salmonella. The extract had a percentage of extractable organic material (EOM) of 7.0% and increased expression of the heme oxygenase (HMOX1) gene in BEAS-2B cells after exposure for 4 hr at 20 µg of EOM/ml. However, the extract did not alter mitochondrial respiration rate as measured by extracellular flux analysis. The extract was most mutagenic in TA100 +S9, indicative of a role for polycyclic aromatic hydrocarbons (PAHs), reflective of the high concentrations of PAHs in the emissions (1 g/kg of oil consumed). The extract had a mutagenicity emission factor of 1.8 ± 0.1 × 10 5 revertants/megajoule thermal in TA98 +S9, which was greater than that of diesel exhaust and within an order of magnitude of open burning of wood and plastic. Thus, organics from PM 2.5 of burning oil can induce oxidative responses in human airway epithelial cells and are highly mutagenic. Environ. Mol. Mutagen. 58:162-171, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Comparative efficiency of chemical and radiation mutagens on two Cicer arietinum Rhizobial strains

Energy Technology Data Exchange (ETDEWEB)

Khare, A K; Shinde, D A; Nayak, M L [Jawaharlal Nehru Krishi Vishwa Vidyalaya, Indore (India)

1982-03-01

A comparison of efficacy due to chemical and radiation mutagens on morphology, nutritional totipotence and symbiotic character of two Cicer arietinum rhizobia has been made. The mutants produced as a result of radiations (gamma and UV rays) differed from parents in that, the mutant colony size was bigger and gelatinase activity was higher. The mutants were not deficient nutritionally, had wider host range and the size and number of nodules produced were higher. Radiation mutagenic effects were more pronounced than chemical mutagens. The mutants derived from chemicals were not as efficient as radiation mutants although they were better than parents in total nodulation.

Study on mutagenic and toxic compounds in lake water used as drinking water supply

International Nuclear Information System (INIS)

Monarca, S.; Zanardini, A.

1996-01-01

Trace amounts of mutagenic and toxic substances are frequently found in drinking water, causing a great concern for their potential health effects. Aim of this work is to develop a reliable and efficient screening method for detecting aquatic mutagens and toxins in surface water used for human consumption. For this purpose different methods of concentration of lake water have been experimented by using three different solid phase extraction systems at different pHs and studying the adsorbates by means of a mutagenicity test (Ames test), a toxicity test (LUMIStox) and chemical analysis (GC,MS). This integrated chemical/biological approach showed to be a suitable system for the preliminary choice of an efficient screening method for aquatic mutagens and toxins and to give useful data for the evaluation of potential health hazards

Study on increasing mutagenic efficiency of radiation breeding for rice

International Nuclear Information System (INIS)

Wan Xianguo; Pang Boliang; Zhu Xiaoqi

1993-04-01

Increasing mutagenic efficiency and improving selection method are of important topics for crop mutation breeding. Investigation on the radiation breeding for rice (Oryza Sativa L.) showed that the crossing in combination with gamma ray irradiation or laser irradiation and proper selection of dosage rate can increase mutagenic efficiency. According to the correlation of phenotype in M 1 generation and mutation frequency in M 2 for rice, the materials with certain characters were chose as seeds, thus the works of generation selections will be reduced

[EVALUATION OF THE CYTOGENETIC AND MUTAGEN-MODIFYING ACTIVITY OF CAFFEINE IN MOUSE BONE MARROW CELLS].

Science.gov (United States)

Durnev, A D; Kulakova, A V; Zhanataev, A K; Oganesiants, L A

2015-01-01

The cytogenetic and mutagen-modifying activity of caffeine was studied with the method of chromosomal aberrations in bone marrow cells of mice hybrids F1 CBAxC57BL/6. Caffeine per se was administered intragastrically or intraperitoneally, and in combination with mutagens--intragastrically. Mutagens injected intraperitoneally. Caffeine at doses of 10 and 100 mg/kg (single dose) and 10 mg/kg (five days) in parenteral administration and oral introduction failed to possess cytogenetic activity. In combination with mutagens caffeine (1, 10 and 100 mg/kg) had no effect on the cytogenetic activity of dioxydine (200 mg/kg/intraperitoneally) for a single coadministration, five-day pre or five-day coadministration. In combination with other mutagens under the same processing conditions caffeine at doses of 10 and 100 mg/kg significantly increased cytogenetic effects of cyclophosphamide (20 mg/kg) in the pretreatment of the animals and at the dose of 100 mg/kg significantly attenuated the cytogenetic effect of cisplatin (5 mg/kg) in single and repeated co-administration. Thus we have shown the absence of caffeine cytogenetic activity in vivo and showed the multidirectional effect of caffeine in doses far exceeding its daily consumption, to the manifestation ofcytogenetic effects of certain chemical mutagens in some modes of processing animals.

Bacterial mutagenicity and mammalian cell DNA damage by several substituted anilines.

Science.gov (United States)

Zimmer, D; Mazurek, J; Petzold, G; Bhuyan, B K

1980-04-01

Several substituted alkyl- and haloanilines were tested for their ability to mutate Salmonella typhimurium and to damage the DNA of mammalian (V79) cells. These results were correlated with their reported carcinogenicity. Of 9 suspected carcinogens, 4 were bacterial mutagens and 4 (out of 7 tested) damaged DNA of V79 cells. The following compounds were weakly mutagenic (less than 150 revertants/mumole): 4-fluoroaniline, 2,3-, 2,4-, 2,5- and 3,4-dimethylaniline, and 2-methyl-4-fluoroaniline. The following compounds were strong mutagens: 2,4,5-trimethylaniline, 2-methyl-4-chloro-, and 2-methyl-4-bromo-, 4-methyl-2-chloro-, 4-methyl-2-bromo- and 2-ethyl-4-chloroaniline. The compounds which damaged DNA in V79 cells were: 2 methyl-4-chloroaniline, 2-methyl-4-bromoaniline, 2,4,5- and 2,4,6-trimethylaniline.

Dietary phenolics as anti-mutagens and inhibitors of tobacco-related DNA adduction in the urothelium of smokers.

Science.gov (United States)

Malaveille, C; Hautefeuille, A; Pignatelli, B; Talaska, G; Vineis, P; Bartsch, H

1996-10-01

Human urine is known to contain substances that strongly inhibit bacterial mutagenicity of aromatic and heterocyclic amines in vitro. The biological relevance of these anti-mutagens was examined by comparing levels of tobacco-related DNA adducts in exfoliated urothelial cells from smokers with the anti-mutagenic activity in corresponding 24-h urine samples. An inverse relationship was found between the inhibition of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-mutagenicity by urine extracts in vitro and two DNA adduct measurements: the level of the putatively identified N-(deoxyguanosine-8-yl)-4-aminobiphenyl adduct and the total level of all tobacco-smoke-related carcinogen adducts including those probably derived from PhIP. Urinary anti-mutagenicity in vitro appears thus to be a good indicator of the anti-genotoxicity exerted by substances excreted in urine, that protect the bladder mucosal cells (and possibly other cells) against DNA damage. These substances appear to be dietary phenolics and/or their metabolites because (i) the anti-mutagenic activity of urine extracts (n = 18) was linearly related to their content in phenolics; (ii) the concentration ranges of these substances in urine extracts were similar to those of various plant phenols (quercetin, isorhamnetin and naringenin) for which an inhibitory effect on the liver S9-mediated mutagenicity of PhIP was obtained; (iii) treatment of urines with beta-glucuronidase and arylsulfatase enhanced both anti-mutagenicity and the levels of phenolics in urinary extracts; (iv) urinary extracts inhibited noncompetitively the liver S9-mediated mutagenicity of PhIP as did quercetin, used as a model phenolics. Several structural features of the flavonoids were identified as necessary for the inhibition of PhIP and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxiline mutagenicity. Fractionation by reverse-phase HPLC and subsequent analysis of two urinary extracts, showed the presence of several anti-mutagenic

Mutagenicity of some alkyl nitrites used as recreational drugs

Energy Technology Data Exchange (ETDEWEB)

Dunkel, V.C.; Cameron, T.P. (National Institute of Health, Bethesda (USA)); Rogers-Back, A.M.; Lawlor, T.E.; Harbell, J.W. (Microbiological Associates Inc., Rockville, MD (USA))

1989-01-01

When the AIDS epidemic was in its earliest stages, and prior to identification of HIV as the etiological factor, the use of volatile nitrites by the male homosexual community to enhance sexual activities appeared to have a significant role in this disease. Preliminary observations indicated that that portion of the male homosexual community which developed Kaposi's sarcoma were also heavy nitrite users. These nitrites had been demonstrated to be mutagenic in bacteria and thus it was postulated that they could be responsible for the appearance of the sarcoma. To evaluate further the genotoxic activity of these chemicals, six nitrites, including those most commonly used by homosexuals for sexual gratification, were selected for testing in the mouse lymphoma TK {plus minus} and Salmonell typhimurium mutagenicity assays. One chemical, n-amyl nitrite, was negative in the mouse lymphoma assay, while the other five chemicals, n-butyl, isobutyl, iso-amyl, sec-butyl, and n-propyl nitrite, were positive. All six compounds were positive in the Salmonella assay. The mutagenic and known toxic effects of these chemicals remain a concern because a large population of teenagers and young adults continue to abuse these substances.

MUTAGEN: Multi-user tool for annotating GENomes

DEFF Research Database (Denmark)

Brugger, K.; Redder, P.; Skovgaard, Marie

2003-01-01

MUTAGEN is a free prokaryotic annotation system. It offers the advantages of genome comparison, graphical sequence browsers, search facilities and open-source for user-specific adjustments. The web-interface allows several users to access the system from standard desktop computers. The Sulfolobus...

Determining effective radiation mutagen dose for garlic (Allium sativum L.)

International Nuclear Information System (INIS)

Taner, Y.; Kunter, B.

2004-01-01

This study was carried out to get database for future garlic mutation breeding studies. For this aim, 0, 5, 10, 15, 20, 25 and 30 Gy doses of Cs 137 (gamma-ray) were applied on garlic cloves as a physical mutagen. 50 cloves were used for each dose. Sixty days after treatment, germination rate and shoot development of cloves were determined. The Effective Mutagen Dose (ED 50 ) was calculated by regression analyses. According to the results, 4.455 Gy dose was found to be effective as ED 50 . (author)

Risks to the offspring from parental occupational exposures

International Nuclear Information System (INIS)

Haas, J.F.; Schottenfeld, D.

1979-01-01

Risks to the offspring of workers with occupational chemical exposures may derive from mutagenic, teratogenic or carcinogenic effects of industrial agents to which the parents are exposed. Evidence for impaired pregnancies and hazards to the offspring of working populations with chemical exposures is, however, very limited. Evidence is reviewed for hazards to the offspring resulting from parental occupational exposure to vinyl chloride, benzene, chloroprene, radiation and petroleum-derived hydrocarbons. Other environmental and behavioral factors with major effects on pregnancy outcome are considered. These include smoking, alcohol, and drug exposures. An approach to surveillance for chromosomal abnormalities in offspring of occupationally exposed parents is outlined

Study of Salmonella typhimurium mutagenicity assay of (E ...

African Journals Online (AJOL)

Study of Salmonella typhimurium mutagenicity assay of (E)-piplartine by the Ames test. AA Morandim-Giannetti, F Cotinguiba, LO Regasini, MC Frigieri, EA Varanda, A Coqueiro, MJ Kato, VS Bolzani, M Furlan ...

Experimental study of mutagenous and mitosis modifying activity of silver nanoparticles

Directory of Open Access Journals (Sweden)

B. S. Kirbik

2015-01-01

Full Text Available Mutagenous and mitosis modifying impact of silver nanoparticles has been studied on outbred mice. Nanoparticles were of round shape with dimensions of 5-50 nm, size of generated organic shell of 2-5 nm, the quantity in 1 mcm3 makes 120-270. Metaphasic analysis of mice bone marrow cells was used as a testing technique. The frequency of chromosome aberrations and mitotic index of preparations were accounted. During single intraperitoneal administration of the agent in the dose of 250 mcg/kg the silver nanoparticles demonstrated mitosis stimulating activity. No mutagenous effect of silver nanoparticles by daily administration for 4 days of 25 mcg/kg and single administration in the dose of 250 mcg/kg has been registered, but there is statistically insignificant tendency of aberrant metaphases increase. Consequently silver nanoparticles in the investigated doses demonstrated no mutagenous activity and can be considered safe for mammalian cells.

Simultaneous Determination of Mutagenicity and Toxicity of ...

African Journals Online (AJOL)

A demonstration of cytotoxicity is required (measurement of cell number, culture confluency and inhibition of mitotic index) for in vitro cytogenetic assays. The study therefore investigated whether delayed cytotoxicity can be used to simultaneously predict mutagenicity and cytotoxicty. Chinese hamster lung cells were ...

Analysis of Hexanitrostilbene (HNS) and Dipicryethane (DPE) for Mutagenicity by the Ames/Salmonella Assay

Energy Technology Data Exchange (ETDEWEB)

Wu, R; Felton, J

2007-10-12

The Ames/Salmonella assay, developed by Professor Bruce Ames at the University of California, Berkeley, is a rapid and sensitive assay for detecting mutagenicity of various chemical compounds (Maron and Ames, 1983). It is a widely accepted short-term assay for detecting chemicals that induce mutations in the histidine (his) gene of Salmonella typhimurium. This is a reverse mutation assay that detects the mutational reversion of his-dependent Salmonella to the his-independent counterpart. Thereby, mutagenic compounds will increase the frequency of occurrence of his-independent bacterial colonies. The assay utilizes the specific genetically constructed strains of bacteria either with or without mammalian metabolic activation enzymes (S9), Aroclor induced rat liver homogenate to assess the mutagenicity of different compounds. In this study, we will use the Ames/Salmonella assay to investigate the mutagenicity of Hexanitrostilbene (HNS) from both Bofors and Pantex, and Dipicryethane (DPE).

Cytotoxic and mutagenic effects of high let charged particles on human skin fibroblasts

International Nuclear Information System (INIS)

Tsuboi, Koji.; Park, M.S.; Chen, D.J.; Yang, T.C.

1992-01-01

Cytotoxic and mutagenic effects of high LET charged particles were quantitatively measured using primary cultures of human skin fibroblasts. The span of LETs selected were from 25 keV/μm(330 MeV/u) to 920 keV/μm (600 MeV/u). Mutations were scored at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus using 6-thioguanine (6-TG) for selection. Exposure to these high LET charged particles resulted in exponential survival curves whereas mutant induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (σ i ) and the action cross-section for mutant induction (σ m ) ranged from 2.2 to 92.0 μm 2 and 0.09 to 5.56 x 10 -3 μm 2 respectively, the maximum values were obtained by 56 Fe with an LET of 200 keV/μm. The mutagenicity (σ m /σ i ) ranged from 2.05 to 7.99 x 10 -5 with the maximum value at 150 keV/μm. Furthermore, the results of multiplex polymerase chain reaction (PCR) of some of the mutants induced by charged particles indicate that higher LET beams are more likely to cause larger deletions in the hprt locus. (author)

Mutagenicity and cytotoxicity of two regioisomeric mercapturic acids and cysteine S-conjugates of trichloroethylene.

NARCIS (Netherlands)

Commandeur, J.N.M.; Boogaard, P.J.; Mulder, G.J.; Vermeulen, N.P.E.

1991-01-01

The mutagenicity, cytotoxicity and metabolism of two regioisomic l-cysteine- and N-acetyl-l-cysteine-S-conjugates of trichloroethylene were studied. The 1,2-dichlorovinyl(1,2-DCV) isomers of both the cysteine conjugate and the mercapturate were much stronger mutagens in the Ames test with Salmonella

Differences in mutagenic and recombinational DNA repair in enterobacteria

International Nuclear Information System (INIS)

Sedgwick, S.G.; Goodwin, P.A.

1985-01-01

The incidence of recombinational DNA repair and inducible mutagenic DNA repair has been examined in Escherichia coli and 11 related species of enterobacteria. Recombinational repair was found to be a common feature of the DNA repair repertoire of at least 6 genera of enterobacteria. This conclusion is based on observations of (i) damage-induced synthesis of RecA-like proteins, (ii) nucleotide hybridization between E. coli recA sequences and some chromosomal DNAs, and (iii) recA-negative complementation by plasmids showing SOS-inducible expression of truncated E. coli recA genes. The mechanism of DNA damage-induced gene expression is therefore sufficiently conserved to allow non-E. coli regulatory elements to govern expression of these cloned truncated E. coli recA genes. In contrast, the process of mutagenic repair, which uses umuC+ umuD+ gene products in E. coli, appeared less widespread. Little ultraviolet light-induced mutagenesis to rifampicin resistance was detected outside the genus Escherichia, and even within the genus induced mutagenesis was detected in only 3 out of 6 species. Nucleotide hybridization showed that sequences like the E. coli umuCD+ gene are not found in these poorly mutable organisms. Evolutionary questions raised by the sporadic incidence of inducible mutagenic repair are discussed

Mutagenicity and genotoxicity of coal fly ash water leachate.

Science.gov (United States)

Chakraborty, Rajarshi; Mukherjee, Anita

2009-03-01

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals-sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significant (Ppercentage (%), tail length (mum), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

Correlation between mixed-function oxidase enzyme induction and aflatoxin B1-induced unscheduled DNA synthesis in the chick embryo, in vivo

International Nuclear Information System (INIS)

Hamilton, J.W.; Bloom, S.E.

1984-01-01

The unscheduled DNA synthesis (UDS) technique has been adapted for use in the chick embryo, in vivo, to determine the relationship between induction of the mixed-function oxidase (MFO) enzyme system and genetic damage from an indirect-acting mutagen-carcinogen. Embryos were injected at 6 days of incubation (DI) with either phenobarbital (PB), a specific inducer of P-450-associated enzyme activities, or 3,4,3',4'-tetrachlorobiphenyl (TCB), a specific inducer of P 1 -450-associated enzyme activities. Aflatoxin B 1 (AFB1) was injected 24 hr later (7 DI), followed by a 5-hr continuous 3 H-thymidine exposure. The livers were removed, prepared for autoradiography, and hepatocytes were scored for an increase in grains/nucleus, indicative of UDS. Aflatoxin B 1 caused a dose-related increase in UDS in all control and induction groups. Phenobarbital-induced embryos had an increased UDS response while TCB-induced embryos had a decreased UDS response, relative to noninduced embryos, for each dosage of AFB1. This suggests that the genotoxicity of an indirect-acting mutagen-carcinogen can be either increased or decreased, in vivo, depending on the inducer used. The chick embryo provides an excellent system for studying the effect of MFO induction on the genotoxicity of promutagen-carcinogens in a developing system

Mutagenicity tests on irradiated food

International Nuclear Information System (INIS)

Johnston-Arthur, T.

1979-01-01

The mutagenicity of ''standard'' food pellets from three different suppliers was tested after radappertization and after sterilization with steam, respectively. The histidine-deficient mutants G-46 and TA-1530 of salmonella typhimurium were used as indicators in a hostmediated assay. The mutant TA-1530 showed a highly sighificant increase of the back-mutation frequency after feeding with pellets irradiated with 3 Mrad gamma radiation. There were, however, large quantitative differences between the products of different suppliers. (G.G.)

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

OpenAIRE

Amrin Shaikh; Darshana Barot; Divya Chandel

2018-01-01

Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation ...

In vivo mutagenicity and clastogenicity of ionizing radiation in nuclear medicine

International Nuclear Information System (INIS)

Kelsey, K.T.

1991-01-01

The overall goal of our research was to investigate the mutagenic and clastogenic effects of exposure to low levels of ionizing radiation to human lymphocytes. Principally, we studied hospital patients referred to a nuclear medicine department for diagnostic cardiac imaging and nuclear medicine technologists who administer radionuclides. Emphasis in the first year, as described in the first progress report, was on optimization of the hprt mutation assay, measurement of mutant frequencies in patients imaged with thallium-201, and measurement of mutant frequencies in controls. Emphasis in the second and third years was on measurements of: (1) chromosome aberrations in patients imaged with thallium-201; (2) mutant frequencies in patients imaged with technetium-99; (3) mutant frequencies in nuclear medicine technicians and physical therapists; and (4) mutant frequencies in patients treated for Hodgkins disease with radiotherapy. The completed work has been published and is described below in more detail

Two dechlorinated chlordecone derivatives formed by in situ chemical reduction are devoid of genotoxicity and mutagenicity and have lower proangiogenic properties compared to the parent compound.

Science.gov (United States)

Legeay, Samuel; Billat, Pierre-André; Clere, Nicolas; Nesslany, Fabrice; Bristeau, Sébastien; Faure, Sébastien; Mouvet, Christophe

2018-05-01

Chlordecone (CLD) is a chlorinated hydrocarbon insecticide, now classified as a persistent organic pollutant. Several studies have previously reported that chronic exposure to CLD leads to hepatotoxicity, neurotoxicity, raises early child development and pregnancy complications, and increases the risk of liver and prostate cancer. In situ chemical reduction (ISCR) has been identified as a possible way for the remediation of soils contaminated by CLD. In the present study, the objectives were (i) to evaluate the genotoxicity and the mutagenicity of two CLD metabolites formed by ISCR, CLD-5a-hydro, or CLD-5-hydro (5a- or 5- according to CAS nomenclature; CLD-1Cl) and tri-hydroCLD (CLD-3Cl), and (ii) to explore the angiogenic properties of these molecules. Mutagenicity and genotoxicity were investigated using the Ames's technique on Salmonella typhimurium and the in vitro micronucleus micromethod with TK6 human lymphoblastoid cells. The proangiogenic properties were evaluated on the in vitro capillary network formation of human primary endothelial cells. Like CLD, the dechlorinated derivatives of CLD studied were devoid of genotoxic and mutagenic activity. In the assay targeting angiogenic properties, significantly lower microvessel lengths formed by endothelial cells were observed for the CLD-3Cl-treated cells compared to the CLD-treated cells for two of the three tested concentrations. These results suggest that dechlorinated CLD derivatives are devoid of mutagenicity and genotoxicity and have lower proangiogenic properties than CLD.

Synthesis and radiolabeling of heterocyclic food mutagens

International Nuclear Information System (INIS)

Rapoport, H.; Waterhouse, A.L.; Thompson, C.M.; O'Connell, J.F.

1986-01-01

The imidazoquinoline and imidazoquinoxaline food mutagens found in cooked meat are being synthesized by unambiguous methods that allow for the preparation of sufficient quantities of material for biological studies. These methods avoid difficult separations of regioisomeric mixtures of products and are designed to allow incorporation of specific high level tritium labeling

The mutagenicity of indoor air particles in a residential pilot field study: Application and evaluation of new methodologies

Science.gov (United States)

Lewtas, Joellen; Goto, Sumio; Williams, Katherine; Chuang, Jane C.; Petersen, Bruce A.; Wilson, Nancy K.

The mutagenicity of indoor air paniculate matter has been measured in a pilot field study of homes in Columbus, Ohio during the 1984 winter. The study was conducted in eight all natural-gas homes and two all electric homes. Paniculate matter and semi-volatile organic compounds were collected indoors using a medium volume sampler. A micro-forward mutation bioassay employing Salmonella typhimurium strain TM 677 was used to quantify the mutagenicity in solvent extracts of microgram quantities of indoor air particles. The mutagenicity was quantified in terms of both mutation frequency per mg of organic matter extracted and per cubic meter of air sampled. The combustion source variables explored in this study included woodburning in fireplaces and cigarette smoking. Homes in which cigarette smoking occurred had the highest concentrations of mutagenicity per cubic meter of air. The average indoor air mutagenicity per cubic meter was highly correlated with the number of cigarettes smoked. When the separate sampling periods in each room were compared, the mutagenicity in the kitchen samples was the most highly correlated with the number of cigarettes smoked.

Vaginal Calculus in a Woman With Mixed Urinary Incontinence and Vaginal Mesh Exposure.

Science.gov (United States)

Winkelman, William D; Rabban, Joseph T; Korn, Abner P

2016-01-01

Vaginal calculi are extremely rare and are most commonly encountered in the setting of an urethrovaginal or vesicovaginal fistula. We present a case of a 72-year-old woman with mixed urinary incontinence and vaginal mesh exposure incidentally found to have a large vaginal calculus. We removed the calculus surgically and analyzed the components. Results demonstrated the presence of ammonium-magnesium phosphate hexahydrate and carbonate apatite.

Mutagenic activity of 2-(2',4'-diaminophenoxy)ethanol in strains TA1538 and TA98 of Salmonella typhimurium.

Science.gov (United States)

Mohn, G; Bouter, S; de Knijff, P

1982-12-01

The mutagenicity of 2-(2',4'-diaminophenoxy)ethanol (2,4-DAPE) was compared with that of 2,4-diaminoanisole (2,4-DAA), a chemically related compound previously used in hair-dye formulations. Both chemicals were tested in standard procedures with the Salmonella/microsome mutagenicity test as described by Ames and colleagues. In several experiments, which extended over a total period of 2 years, 2,4-DAA exhibited definite, but variable mutagenicity toward strain TA1538 when S9 preparations of rat liver induced with Aroclor 1254 were present in the incubation mixtures. The compound 2,4-DAPE did not exhibit detectable mutagenic activity when tested concomitantly under the same experimental conditions. We conclude that 2,4-DAPE is not mutagenic for Salmonella under conditions of the standard mammalian microsome assay with strain TA1538 and TA98 as indicators.

Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system. [Quarterly report, October--December 1991

Energy Technology Data Exchange (ETDEWEB)

1992-01-13

The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

Ames Mutagenicity Assessment of Flavored Water Pipe Tobacco Products :A Cross Sectional Study in Tehran

Directory of Open Access Journals (Sweden)

Shahrzad Sadri

2016-12-01

Full Text Available Waterpipe smoking has become a global youth trend especially in the Middle East countries and Iran . The aim of this study was to determine the mutagenic effects of three most popular flavored tobaccos by four different salmonella typhimurium strains and compare the possible mutagenic effects of the test samples. Ames mutagenicity assessment was conducted according to the OECD guideline using TA100, TA98 , YG1024 and YG1029 strains. Charcoal burned flavored tobaccos of three different flavors including Orange, Double Apple, and Lime Mint were filtered and exposed to all strains after strain identification tests and MIC ,MBC determinations. The Ames test results indicated significant mutagenic effects of tobacco samples in all four test strains when compared with negative control (p≤0.0001. The highest Mutagenic Factor (MF was seen in Double Apple samples using TA 98 (MF=11.5±3.3 . In all experiments, TA strains showed higher sensitivity to the samples than YG strains which suggest these two strains for further regulatory toxicity tests ,policy making purposes and tobacco control programs . Present results represents an important step in understanding the genotoxic potentials of three most popular flavored tobaccos samples of a famous brand in the global markets .

Mutagenicity testing of diethylene glycol monobutyl ether.

Science.gov (United States)

Thompson, E D; Coppinger, W J; Valencia, R; Iavicoli, J

1984-01-01

The mutagenic potential of diethylene glycol monobutyl ether (diEGBE) was examined with a Tier I battery of in vitro assays followed by a Tier II in vivo Drosophila sex-linked recessive lethal assay. The in vitro battery consisted of: the Salmonella mutagenicity test, the L5178Y mouse lymphoma test, a cytogenetics assay using Chinese hamster ovary cells and the unscheduled DNA synthesis (UDS) assay in rat hepatocytes. Results of the Salmonella mutagenicity test, the cytogenetics test, and the rat hepatocyte assay were negative at concentrations up to 20 microL/plate, 7.92 microL/mL, and 4.4 microL/mL, respectively. Toxicity was clearly demonstrated at all high doses. A weak, but dose-related increase in the mutation frequency (4-fold increase over the solvent control at 5.6 microL/mL with 12% survival) was obtained in the L5178Y lymphoma test in the absence of metabolic activation. Results of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay results were assessed by performing the Tier II sex-linked recessive lethal assay in Drosophila in which the target tissue is maturing germinal cells. Both feeding (11,000 ppm for 3 days) and injection (0.3 microL of approximately 14,000 ppm solution) routes of administration were employed in the Drosophila assay. Approximately 11,000 individual crosses with an equal number of negative controls were performed for each route of administration. diEGBE produced no increase in recessive lethals under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6389113

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

International Nuclear Information System (INIS)

Sideropoulos, A.S.; Specht, S.M.; Jones, M.T.

1980-01-01

A simple screening methodology for the determination of mutagenicity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr + and hcr - are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm 2 , chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed 'mutational synergism' [18,20]. We have attempted to apply the procedure for securing data for 'mutational synergism' between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 μg/ml), quinine hydrobromide (50 μg/ml), primaquine diphosphate (50 μg/ml), chloroquine (50 μg/ml), quinine (50 μg/ml) and quinacrine dihydrochloride (25 μg/ml). All drugs tested give synergistic effects with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed. (orig.)

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

Energy Technology Data Exchange (ETDEWEB)

Sideropoulos, A S; Specht, S M; Jones, M T [Duquesne Univ., Pittsburgh, PA (USA). Dept. of Biological Sciences

1980-04-01

A simple screening methodology for the determination of mutagenicity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr/sup +/ and hcr/sup -/ are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm/sup 2/, chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed 'mutational synergism' (18,20). We have attempted to apply the procedure for securing data for 'mutational synergism' between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 ..mu..g/ml), quinine hydrobromide (50 ..mu..g/ml), primaquine diphosphate (50 ..mu..g/ml), chloroquine (50 ..mu..g/ml), quinine (50 ..mu..g/ml) and quinacrine dihydrochloride (25 ..mu..g/ml). All drugs tested give synergistic effects with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed.

Impacts of compact growth and electric vehicles on future air quality and urban exposures may be mixed.

Science.gov (United States)

Yu, Haofei; Stuart, Amy L

2017-01-15

'Smart' growth and electric vehicles are potential solutions to the negative impacts of worldwide urbanization on air pollution and health. However, the effects of planning strategies on distinct types of pollutants, and on human exposures, remain understudied. The goal of this work was to investigate the potential impacts of alternative urban designs for the area around Tampa, Florida USA, on emissions, ambient concentrations, and exposures to oxides of nitrogen (NO x ), 1,3-butadiene, and benzene. We studied three potential future scenarios: sprawling growth, compact growth, and 100% vehicle fleet electrification with compact growth. We projected emissions in the seven-county region to 2050 based on One Bay regional visioning plan data. We estimated pollutant concentrations in the county that contains Tampa using the CALPUFF dispersion model. We applied residential population projections to forecast acute (highest hour) and chronic (annual average) exposure. The compact scenario was projected to result in lower regional emissions of all pollutants than sprawl, with differences of -18%, -3%, and -14% for NO x , butadiene, and benzene, respectively. Within Hillsborough County, the compact form also had lower emissions, concentrations, and exposures than sprawl for NO x (-16%/-5% for acute/chronic exposures, respectively), but higher exposures for butadiene (+41%/+30%) and benzene (+21%/+9%). The addition of complete vehicle fleet electrification to the compact scenario mitigated these in-county increases for the latter pollutants, lowering predicted exposures to butadiene (-25%/-39%) and benzene (-5%/-19%), but also resulted in higher exposures to NO x (+81%/+30%) due to increased demand on power plants. These results suggest that compact forms may have mixed impacts on exposures and health. 'Smart' urban designs should consider multiple pollutants and the diverse mix of pollutant sources. Cleaner power generation will also likely be needed to support aggressive

Diffusion measures indicate fight exposure-related damage to cerebral white matter in boxers and mixed martial arts fighters.

Science.gov (United States)

Shin, W; Mahmoud, S Y; Sakaie, K; Banks, S J; Lowe, M J; Phillips, M; Modic, M T; Bernick, C

2014-02-01

Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

Ascorbic acid reduced mutagenicity at the HPRT locus in CHO cells against thermal neutron radiation

International Nuclear Information System (INIS)

Kinashi, Yuko; Sakurai, Yoshinori; Masunaga, Shinichiro; Suzuki, Minoru; Nagata, Kenji; Ono, Koji

2004-01-01

We investigated the biological effects of the long-lived radicals induced following neutron irradiation. It has been reported that radiation-induced long-lived radicals were scavenged by post-irradiation treatment of ascorbic acid (Koyama, 1998). We studied the effects of ascorbic acid acting as a long-lived radical scavenger on cell killing and mutagenicity in Chinese hamster ovary cells against thermal neutrons produced at the Kyoto University Research reactor. Ascorbic acid was added to cells 30 min after neutron irradiation and removed 150 min after irradiation. The biological end point of cell survival was measured by colony formation assay. The mutagenicity was measured by the mutant frequency in the HPRT locus. The post-irradiation treatment of ascorbic acid did not alter the cell killing effect of neutron radiation. However, the mutagenicity was decreased, especially when the cells were irradiated with boron. Our results suggested that ascorbic acid scavenged long-lived radicals effectively and caused apparent protective effects against mutagenicity of boron neutron capture therapy

Intramolecular tautomerisation and the conformational variability of some classical mutagens – cytosine derivatives: quantum chemical study

Directory of Open Access Journals (Sweden)

Hovorun D. M.

2011-04-01

Full Text Available Aim. To determine the lifetime of the mutagenic cytosine derivatives through the investigation of the physicochemical mechanisms of their intramolecular proton transfer. Methods. Non-empirical quantum chemistry, the analysis of the electron density by means of Bader’s atoms in molecules (AIM theory and physicochemical kinetics were used. Results. It is shown that the modification of all investigated compounds, except DCyt, prevents their pairing in both mutagenic and canonical tautomeric forms with a base which is an interacting partner. This effect can inhibit their mutagenic potential. It is also established that Watson-Crick tautomeric hypothesis can be formally expanded for the investigated molecules so far as a lifetime of the mutagenic tautomers much more exceeds characteristic time for the incorporation of one nucleotides pair by DNA biosynthesis machinery. It seems that just within the frame of this hypothesis it will be possible to give an adequate explanation of the mechanisms of mutagenic action of N4-aminocytosine, N4-methoxycytosine, N4-hydroxycytosine and N4dehydrocytosine, which have much more energy advantageous imino form in comparison with amino form. Conclusions. For the first time the comprehensive conformational analysis of a number of classical mutagens, namely cytosine derivatives, has been performed using the methods of non-empirical quantum chemistry at the MP2/6-311++G (2df,pd//B3LYP/6-311++G(d,p level of theory

Cloning of Salmonella typhimurium DNA encoding mutagenic DNA repair

International Nuclear Information System (INIS)

Thomas, S.M.; Sedgwick, S.G.

1989-01-01

Mutagenic DNA repair in Escherichia coli is encoded by the umuDC operon. Salmonella typhimurium DNA which has homology with E. coli umuC and is able to complement E. coli umuC122::Tn5 and umuC36 mutations has been cloned. Complementation of umuD44 mutants and hybridization with E. coli umuD also occurred, but these activities were much weaker than with umuC. Restriction enzyme mapping indicated that the composition of the cloned fragment is different from the E. coli umuDC operon. Therefore, a umu-like function of S. typhimurium has been found; the phenotype of this function is weaker than that of its E. coli counterpart, which is consistent with the weak mutagenic response of S. typhimurium to UV compared with the response in E. coli

Gene mutation, quantitative mutagenesis, and mutagen screening in mammalian cells: study with the CHO/HGPRT system

International Nuclear Information System (INIS)

Hsie, A.W.

1980-01-01

We have employed CHO cells to develop and define a set of stringent conditions for studying mutation induction to TG resistance. Several lines of evidence support the CHO/HGPRT system as a specific-locus mutational assay. The system permits quantification of mutation at the HGPRT locus induced by various physical and chemical mutagens. The quantitative nature of the system provides a basis for the study of structure-function relationships of various classes of chemical mutagens. The intra- and interlaboratory reproducibility of this system suggests its potential for screening environmental agents for mutagenic activity

Codon cassette mutagenesis: a general method to insert or replace individual codons by using universal mutagenic cassettes.

OpenAIRE

Kegler-Ebo, D M; Docktor, C M; DiMaio, D

1994-01-01

We describe codon cassette mutagenesis, a simple method of mutagenesis that uses universal mutagenic cassettes to deposit single codons at specific sites in double-stranded DNA. A target molecule is first constructed that contains a blunt, double-strand break at the site targeted for mutagenesis. A double-stranded mutagenic codon cassette is then inserted at the target site. Each mutagenic codon cassette contains a three base pair direct terminal repeat and two head-to-head recognition sequen...

In vitro evaluation of mutagenicity and genotoxicity of sitagliptin ...

African Journals Online (AJOL)

Keywords: Sitagliptin, Artificial sweeteners, Comet assay, DNA damage, Ames assay, Genotoxicity,. Mutagenicity. Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,. International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African.

Radiation-induced mutagenicity and lethality in Salmonella typhimurium

International Nuclear Information System (INIS)

Isildar, M.; Bakale, G.

1983-01-01

The mutagenic and lethal effects of ionizing radiation on histidine-deficient auxotrophs of Salmonella typhimurium were studied to improve the understanding of radiation damage to DNA. The auxotrophs were divided into two groups - one which is sensitive to base-pair substitutions and another sensitive to frameshifts. These groups were composed of parent-daughter pairs in which the chemical mutagenicity enhancing plasmid, pKM101, is absent in the parent strain and present in the daughter. Co-60 #betta#-radiation and 250 kV x-rays were used to irradiate the bacteria. Irradiation of the frameshift - sensitive strains which carry the pKm101 plasmid doubled the absolute number of induced revertants whereas irradiation of the base-pair substitution sensitive strain which also carries the pKm101 plasmid produced nearly no change in the number of induced revertants. A nearly negligible effect on the mutation rate was observed for all parent strains

Effectiveness and efficiency of certain mutagens in Linum usitatissimum L

International Nuclear Information System (INIS)

Lateef, M.A.; Nizam, J.

1985-01-01

The effectiveness and efficiency of gamma rays, hydrazine, hydroxylamine, ethylmethane sulphonate and mitomycin-C. mutagens were studied on the basis of chlorophyll mutations in Linum usitatissimum L. (author)

An Evaluation of the Mode of Action Framework for MutagenicCarcinogens Case Study II: Chromium (VI).

Science.gov (United States)

In response to the 2005 revised U.S Environmental Protection Agency’s (EPA) Cancer Guidelines, a strategy is being developed to include all mutagenicity and other genotoxicity data with any additional information to determine whether a carcinogen operates through a mutagenic mode...

Using Saccharomyces cerevisiae to Test the Mutagenicity of Household Compounds: An Open Ended Hypothesis-Driven Teaching Lab

OpenAIRE

Marshall, Pamela A.

2007-01-01

In our Fundamentals of Genetics lab, students perform a wide variety of labs to reinforce and extend the topics covered in lecture. I developed an active-learning lab to augment the lecture topic of mutagenesis. In this lab exercise, students determine if a compound they bring from home is a mutagen. Students are required to read extensive background material, perform research to find a potential mutagen to test, develop a hypothesis, and bring to the lab their own suspected mutagen. This lab...

Oxidative Damage and Mutagenic Potency of Fast Neutron and UV-B Radiation in Pollen Mother Cells and Seed Yield of Vicia faba L.

Directory of Open Access Journals (Sweden)

Ekram Abdel Haliem

2013-01-01

Full Text Available In recent years, there has been a great deal of attention toward free radicals, reactive oxygen species (ROS generated by exposure of crop plant cells to physical radiations. Henceforth, the current study was planned to compare oxidative stress and mutagenic potential of different irradiation doses of fast neutron (FN and UV-B on meiotic-pollen mother cells (PMCs, pollen grains (PGs and seeds yielded from irradiated faba beans seedlings. On the cytogenetic level, each irradiation type had special interference with DNA of PMC and exhibited wide range of mutagenic action on the frequency and type of chromosomal anomalies, fertility of PGs and seed yield productivity based on the irradiation exposure dose and radiation sensitivity of faba bean plants compared with un-irradiated ones. On the molecular level, SDS-PAGE and RPAD-PCR analyses of seeds yielded from irradiated seedlings exhibited distinctive polymorphisms based on size, intensity, appearance, and disappearance of polypeptides bands compared with un-irradiated ones. The total values of protein and DNA polymorphisms reached 88% and 90.80% respectively. The neutron fluency (2.3 × 106 n/cm2 and UV-B dose for 1 hr were recorded as bio-positive effects. The present study proved that genetic variations revealed by cytogenetic test could be supported by gene expression (alterations in RAPD and protein profiles.

Mutagens and carcinogens in foods. Epidemiologic review.

OpenAIRE

Hislop, T. G.

1993-01-01

Evidence that diet contributes to the development of cancer is strengthening. This paper examines mutagens and carcinogens, such as naturally occurring substances, products of cooking and food processing, intentional and unintentional additives, and contaminants, found in foods. Such substances are present in minute quantities in the diets of average Canadians. Indication of health risk is largely limited to experimental laboratory evidence.

Mutagens and carcinogens in foods. Epidemiologic review.

Science.gov (United States)

Hislop, T. G.

1993-01-01

Evidence that diet contributes to the development of cancer is strengthening. This paper examines mutagens and carcinogens, such as naturally occurring substances, products of cooking and food processing, intentional and unintentional additives, and contaminants, found in foods. Such substances are present in minute quantities in the diets of average Canadians. Indication of health risk is largely limited to experimental laboratory evidence. PMID:8499796

Mutagenic assessment of Lithobates catesbeianus tadpoles exposed to the 2,4-D herbicide in a simulated realistic scenario.

Science.gov (United States)

Mesak, Carlos; de Oliveira Mendes, Bruna; de Oliveira Ferreira, Raíssa; Malafaia, Guilherme

2018-05-01

The aim of the current study is to assess possible erythrocyte mutagenic effects on Lithobates catesbeianus tadpoles exposed to water contaminated with 2,4-D. In order to do so, tadpoles were exposed to a predictive and environmentally relevant herbicide concentration (1.97 mg/L), which is likely to be found in lentic environments formed by superficial water runoffs in pasture areas where the herbicide was applied. The micronucleus test, as well as tests for other nuclear abnormalities, was conducted after 3, 5, and 9 days of exposure (d.e.). Changes in the biomass and mouth-cloaca length or interference in the larval development of the animals (in the three evaluated times) were not recorded. However, tadpoles exposed to 2,4-D showed the highest total number of nuclear abnormalities, as well as the highest frequency of binucleated erythrocytes and kidney-shaped nuclei (shortly after 3 d.e.). The micronucleus frequency was also higher in animals exposed to 2,4-D (in the 3rd, 5th, and 9th d.e.), as well as the frequency of binucleated cells (3rd, 5th, and 9th d.e.) presenting notched (9th d.e.) and blebbled (9th d.e.) nuclei in comparison to those of the control, after 5 and 9 days of exposure. Therefore, the current study is a pioneer in showing that 2,4-D has a mutagenic effect on L. catesbeianus tadpoles, even at low concentrations (environmentally relevant) and for a short period of time, a fact that may lead to direct losses in anuran populations living in areas adjacent to those subjected to 2,4-D herbicide application.

The effective use of physical and chemical mutagen in the induction of mutation for crop improvement in Malaysia

International Nuclear Information System (INIS)

Abdul Rahim Harun

2001-01-01

The earliest work of induced mutations breeding program in Malaysia was reported in 1967. The project was carried out by Rubber Research Institute of Malaysia using x-radiation in an attempt to improve rubber trees for dwarfism and disease resistance. Subsequently, more efforts were taken up by the universities to promote the technology for genetic changes and creation of new genetic resources, particularly in crops that are not easily achievable through conventional techniques. Gamma radiation is always been used as physical mutagen, while ethyl methane sulfonate (EMS) was a popular chemical mutagen used in induced mutation breeding in the country. Gamma rays is an effective mutagen to which more than 30 potential mutants were produced up to now through mutagenesis of several important food crops and ornamental plants. Although chemical mutagen such as EMS were reported being used, the result is not so convincing as compared to gamma radiation. Malaysian Institute for Nuclear Technology Research (MINT) has initiated and promoted nuclear technique in mutation breeding for the improvement of importance food crops such as rice, legume and other potential crops for export, like fruit trees and ornamentals. Gamma radiation is the main source of mutagen used in mutation-breeding programme at MINT. The effectiveness of these two mutagens were verified with mutants derived through induced mutation breeding in the country which some mutant has shown outstanding improvement and released as new varieties and cultivars. This paper summarises and discuss the effects as well as achievement attained through the use of ionizing radiation and chemical mutagen in plant mutation breeding in Malaysia. (author)

The effective use of physical and chemical mutagen in the induction of mutation for crop improvement in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Abdul Rahim Harun [Malaysian Institute for Nuclear Technology Research, Bangi, Selangor (Malaysia)

2001-03-01

The earliest work of induced mutations breeding program in Malaysia was reported in 1967. The project was carried out by Rubber Research Institute of Malaysia using x-radiation in an attempt to improve rubber trees for dwarfism and disease resistance. Subsequently, more efforts were taken up by the universities to promote the technology for genetic changes and creation of new genetic resources, particularly in crops that are not easily achievable through conventional techniques. Gamma radiation is always been used as physical mutagen, while ethyl methane sulfonate (EMS) was a popular chemical mutagen used in induced mutation breeding in the country. Gamma rays is an effective mutagen to which more than 30 potential mutants were produced up to now through mutagenesis of several important food crops and ornamental plants. Although chemical mutagen such as EMS were reported being used, the result is not so convincing as compared to gamma radiation. Malaysian Institute for Nuclear Technology Research (MINT) has initiated and promoted nuclear technique in mutation breeding for the improvement of importance food crops such as rice, legume and other potential crops for export, like fruit trees and ornamentals. Gamma radiation is the main source of mutagen used in mutation-breeding programme at MINT. The effectiveness of these two mutagens were verified with mutants derived through induced mutation breeding in the country which some mutant has shown outstanding improvement and released as new varieties and cultivars. This paper summarises and discuss the effects as well as achievement attained through the use of ionizing radiation and chemical mutagen in plant mutation breeding in Malaysia. (author)

Genotoxic and mutagenic properties of Bauhinia platypetala extract, a traditional Brazilian medicinal plant.

Science.gov (United States)

Santos, Francisco José Borges Dos; Moura, Dinara Jaqueline; Péres, Valéria Flores; Sperotto, Angelo Regis de Moura; Caramão, Elina Bastos; Cavalcante, Ana Amélia de Carvalho Melo; Saffi, Jenifer

2012-12-18

Bauhinia platypetala Burch. is a traditionally used Brazilian medicinal plant, although no evidence in the literature substantiates the safety of its use. The aim of this study was to investigate the safety of the ethanolic extract and the ethereal fraction of B. platypetala leaves. The identification of chemical compounds from the B. platypetala ethanolic extract and its ethereal fraction was performed by GC/MS and ESI-MS/MS. The plant's toxicological, cytotoxic, mutagenic and genotoxic properties were determined in Saccharomyces cerevisiae strains and V79 cell culture by survival assays and comet assay. The major compound identified in the B. platypetala ethanolic extract is palmitic acid, kaempferitirin and quercitrin, while the B. platypetala ethereal fraction was found to be rich in phytol, gamma-sitosterol and vitamin E. Moreover, the results indicated that the B. platypetala ethanolic extract has an anti-oxidative effect against H(2)O(2) in yeast. In addition, the B. platypetala ethanolic extract did not induce mutagenic effects on the S. cerevisiae N123 strain, but the ethereal fraction of B. platypetala at higher concentrations (250-500 μg/mL) induced cytotoxicity and mutagenicity. A slight cytotoxic effect was observed in mammalian V79 cells; however, both the B. platypetala ethanolic extract and its ethereal fraction were able to induce DNA strand breaks in V79 cells, as detected by the alkaline comet assay. The B. platypetala ethanolic extract has antioxidant action and showed absence of mutagenic effects in yeast S. cerevisiae. On the other hand B. platypetala ethereal fraction is mutagenic and does not show antioxidant activity in yeast. In mammalian cells B. platypetala ethanolic extract and it's ethereal fraction induce cyotoxic and genotoxic action. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Mutagenic effect of tritated water on spores of Bacillus subtilis

International Nuclear Information System (INIS)

Tanooka, H.; Munakata, N.

1978-01-01

The mutagenic effect of tritiated water was observed with spores of Bacillus subtilis polA strain suspended in 50 mCi/ml of tritiated water for various intervals. Dose rate given by tritium beta particles to spore core was estimated to be 400 rad/hr from some assumptions and E. coli data computed by Bockrath et al. and Sands et al. The initial mutation rate was 4.2 x 10 -9 mutants/rad, as compared with 2.4 x 10 -9 mutants/rad for 60 Co γ rays and 3.3 x 10 -9 mutants/rad for 30-kVp x rays. The mutagenic effect of tritiated water on spores is most likely due to beta particle ionizing radiation damage

Mutagenic action of radiation with different LET on Bacillus subtilis cells

International Nuclear Information System (INIS)

edinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" data-affiliation=" (Obedinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" >Borejko, A.V.; edinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" data-affiliation=" (Obedinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" >Krasavin, E.A.

1997-01-01

The induction of the his - -> his + mutants in vegetative and spores of Bacillus subtilis wild type cells irradiated with γ-rays and helium ions (LET = 20-80 keV/μm) has been investigated. It was shown that the dose dependence of the mutation induction in vegetative cells is described by a linear-quadratic function of dose in case of both γ-rays and helium ions. RBE (LET) dependencies on the lethal and mutagenic effect of radiation have a local maximum. The maximum of RBE (LET) dependence on the mutagenic assay is shifted at the low region of LET in comparison with the lethal effect of irradiation. (author)

Is ultraviolet enhanced reactivation of mammalian virus mutagenic

International Nuclear Information System (INIS)

Bockstahler, L.E.; Hellman, K.B.; Cantwell, J.M.; Strickland, A.

1981-01-01

Ultraviolet enhanced reactivation consists of an increase in the survival of certain uv-irradiated mammalian viruses when assayed for infectivity in uv-irradiated host mammalian cells, as compared with unirradiated cells. In this report ultraviolet enhanced reactivation is described, and a review is presented of investigations from this and other laboratories to establish whether or not this process is mutagenic. The answer to this question may help establish if error-prone DNA repair is induced in irradiated mammalian cells. We approached the mutagenesis question by examining the phenotypic reversion of a uv-irradiated temperature sensitive mutant of Herpes simplex virus to wild type growth in uv-irradiated monkey kidney cells. Apparent reversion was observed in both irradiated and unirradiated cells. No correlation could be found between the extent of reversion and uv exposure to the cells. The conclusions from studies reported by other investigators using various mammalian virus mutagenesis systems are conflicting. It was generally agreed that viral mutagenesis occurs when irradiated virus is passaged through either irradiated or unexposed cells. However, in some studies it was found that the frequency of mutagenesis in irradiated cells was greater than that in unirradiated cells, while in other studies increased mutagenesis in irradiated cells was not observed

(Anti)mutagenic and immunomodulatory properties of quercetin glycosides

Czech Academy of Sciences Publication Activity Database

Valentová, Kateřina; Šíma, Petr; Rybková, Z.; Křižan, Jiří; Malachová, K.; Křen, Vladimír

2016-01-01

Roč. 96, č. 5 (2016), s. 1492-1499 ISSN 0022-5142 R&D Projects: GA ČR(CZ) GAP301/11/0767; GA MŠk(CZ) LD14096 Institutional support: RVO:61388971 Keywords : quercetin glycosides * (anti)mutagenicity * mice Subject RIV: EE - Microbiology, Virology Impact factor: 2.463, year: 2016

Space mutagenic effect of Trichoderma reesei

International Nuclear Information System (INIS)

Tian Xingshan; Zhou Fengzheng; Huang Xiaoguang; Kuang Zheshi; Pan Mushui; Li Guoli; Guo Yong

2005-01-01

The slant mycelia cultured with or without mutagenic agent diethyl sulfate (DS) and spores of Trichoderma reesei were loaded in the 18th returning satellite. Systematical screening showed that the life cycle and morphology of some strains had changed after space flight. After selection and domestication, 3 mutant strains with high cellulose enzyme activity were isolated. The cellulose enzyme productivities of the mutants were significantly increased more than 50%, and the mutant were generically stable. (authors)

Mutagenicity assessment of two herbal medicines, Urtan and Carmint in human leukocytes by single cell gel electrophoresis

International Nuclear Information System (INIS)

Jalili, M.; Hatami, A.; Kalantari, H.; Kalantar, E.

2006-01-01

The use of herbal medicine is an old and still widespread particle, which makes studies their genotoxicity essential. Urtan and Carmint are examples of herbal medicines used in Iran which used for the treatment of hyperplasia, diuretic, urinary diffusion and antispasmodic action, carminative gastrointestinal disfunction respectively. The aim of this study was to evaluate the mutagenicity of these herbal medicines in human leukocytes by Single Cell Gel Electrophoresis (SCGE). Both the herbal medicines were used at four concentrations (0.046, 0.092, 0.138 and 0.184/ 100 ml). The results were compared against positive (Cr VI) and negative (no mutagen) control groups. Fluorescence microscope was used to observe the DNA damage in randomly selected cells, which were stained with ethidium bromide. Microscopic observation of the affected cells due to Urtan and Carmint was encouraging as compared to previous studies using SCGE. Both Urtan and Carmint exhibited considerable DNA damage to the blood cells. For example, Urtan at o.184 g/100ml concentration had almost 23% mutagenic effect and as the concentration increased the mutagenic effect also increased. Similarly Carmint exhibited considerable DNA damage on blood cells. Therefore, both the herbal medicines may have some mutagenic effect. (author)

Studies on tritium (tritiated water) mutagenicity and teratogenicity in rats

International Nuclear Information System (INIS)

Yagova, A.Kh.

1979-01-01

Single parental exposures to a range of tritium (tritiated water) activities, injecterd intraperitoneally, were used to study induction of genetic damage and effects on prenatal development in rats. In the male, treatment of postmeiotic stages of spermatogenesis was found to produce genetic damage, as judged by the dominant lethality test, at activity levels of the order of 1.0 microcurie/g body weight and above; when treating spermatogonia, no genetic damage was detected by this test. In the female, induced dominant lethality was observed after exposing oocytes in growing follicles to a tritium activity level of 10 microcurie/g b.w. Cytogenetic analysis of spermatocytes in meiosis disclosed increased frequency of reciprocal translocations after exposure of premeiotic cells (spermatogonia) to activities above 7 microcurie/g b.w., the effect tending to rise with increase in activity aministered per gram of body weight. Maternal treatment during early pregnancy was shown to raise prenatal death rate only at activities above 0.1 microcurie/g b.w; with such low activities, no discernible effects on postnatal development were noted, judging by postnatal death rate and increase in offspring body weight with time. In conclusion, experimental evidence was obthained that a tritiated water activity level of 0.1 microcurie per gram body weight (which is one order of magnitude above the annual limit of intake of tritiated water for members of the public) appears to produce no mutagenic effect and exert no influence upon the embryo

Petroleum distillates suppress in vitro metabolic activation: higher [S-9] required in the Salmonella/microsome mutagenicity assay.

Science.gov (United States)

Carver, J H; Machado, M L; MacGregor, J A

1985-01-01

To determine if standard conditions used in the Salmonella/mammalian microsome mutagenicity assay could reliably screen complex petroleum samples, two high-boiling (700-1,070 degrees F) distillates and their separated aromatic fractions were tested. The initial mutagenic activities were inconsistent with the samples' known polyaromatic hydrocarbon (PAH) contents and observed potencies in a dermal carcinogenesis bioassay. A significant mutagenic response was observed only at S-9 concentrations 5 to 10 times higher than those used in the standard assay, supporting the use of elevated levels of S-9 in the Salmonella/microsome assay to assess the carcinogenic potential of petroleum-derived materials. All four samples masked the expected mutagenic activity of added PAHs (benzo[a]pyrene and perylene). Data suggested that petroleum distillates suppress the functional efficacy of the S-9; possible mechanisms are discussed.

Antigenotoxic effects of Citrus aurentium L. fruit peel oil on mutagenicity of two alkylating agents and two metals in the Drosophila wing spot test.

Science.gov (United States)

Demir, Eşref; Kocaoğlu, Serap; Cetin, Huseyin; Kaya, Bülent

2009-07-01

Antigenotoxic effects of Citrus aurentium L. (Rutaceae) fruit peel oil (CPO) in combination with mutagenic metals and alkylating agents were studied using the wing spot test of D. melanogaster. The four reference mutagens, potassium dichromate (K2Cr2O7), cobalt chloride (CoCl2), ethylmethanesulfonate (EMS), and N-ethyl-N-nitrosourea (ENU) were clearly genotoxic. CPO alone at doses from 0.1 to 0.5% in Tween 80 was not mutagenic and did not enhance the mutagenic effect of the reference mutagens. However, antigenotoxic effects of CPO were clearly demonstrated in chronic cotreatments with mutagens and oil, by a significant decrease in wing spots induced by all four mutagens. The D. melanogaster wing spot test was found to be a suitable assay for detecting antigenotoxic effects in vivo. Copyright 2009 Wiley-Liss, Inc.

Induction of transposon TN1 translocation under the action of different mutagens

International Nuclear Information System (INIS)

Kubanejshvili, M.G.; Smirnov, S.P.; Tarasov, V.A.

1983-01-01

Migration of ampicillin transposon Tn1 under normal conditions in Escherichia coli cells proceeds with low frequency (10 -4 transpositions for cell). The low transposition frequency is conditioned by the transposition repression, realized by the gene-repressor in transposon structure and, probably, by other regulating genes of the bacterium-host. E. coli cell treatment by physical and chemical mutagens resulted in induction of translocation of ampicillin transposon Tn1 from plasmid RP4 into other replicons. Mitomycin C and ultraviolet radiation produced stronger inducing effect as compared to nitroso-guanidine (NG). The effect of the given mutagens on transposition Tn1 correlated with their activating capacity with respect to inducible SOS-functions of E coli. The mutation of rec A didn't influence on spontaneous Tn1 transposition, but blocked completely the induction of transposition process under mutagen effect. The relationship of inducible transposition with SOS-functions in E. coli cells, controlled by recA and lexA genes, as well as the possible role of the process in genetic microorganism variability are discussed in the paper

FTIR analysis and evaluation of carcinogenic and mutagenic risks of nitro-polycyclic aromatic hydrocarbons in PM1.0.

Science.gov (United States)

Schneider, Ismael Luís; Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana Milena; Silva E Silva, Gabriel; Balzaretti, Naira; Braga, Marcel Ferreira; Oliveira, Luís Felipe Silva

2016-01-15

Nitro-polycyclic aromatic hydrocarbons (NPAHs) represent a group of organic compounds of significant interest due to their presence in airborne particulates of urban centers, wide distribution in the environment, and mutagenic and carcinogenic properties. These compounds, associated with atmospheric particles of size PM1.0) using infrared spectrometry. Carcinogenic and mutagenic risks of the studied NPAHs associated with PM1.0 samples were also determined for two sampling sites: Canoas and Sapucaia do Sul. The results showed that NPAH standard spectra can effectively identify NPAHs in PM1.0 samples. The transmittance and emissivity sample spectra showed broader bands and lower relative intensity than the standard NPAH spectra. The carcinogenic risk and the total mutagenic risk were calculated using the toxic equivalent factors and mutagenic potency factors, respectively. Canoas showed the highest total carcinogenic risk, while Sapucaia do Sul had the highest mutagenic risk. The seasonal analysis suggested that in the study area the ambient air is more toxic during the cold periods. These findings might of significant importance for the decision and policy making authorities.

Mutagenic and antimutagenic potentials of fruit juices of five ...

African Journals Online (AJOL)

Mutagenic and antimutagenic activities of freeze dried fruit juices (FDFJ) of Morinda elliptica Ridl. (Rubiaceae), Morinda citrifolia L. (Rubiaceae), Averrhoa bilimbi L. (Oxalidaceae), Phyllantus acidus (L.) Skeels (Phyllantaceae) and Myristica fragrans Houtt. (Myristicaceae) in Allium cepa L was evaluated. Testing the ...

Genotoxicity and mutagenicity of solid waste leachates: A review

African Journals Online (AJOL)

user

2013-07-03

Jul 3, 2013 ... There is need for a shift from waste disposal to sustainable waste management. Awareness on possible health ... Key words: Solid waste leachate, genotoxicity, mutagenicity, environmental pollution. INTRODUCTION. Solid wastes .... landfills and incineration residues from Japan include persistent organic ...

Circular dichroism study of the interaction between mutagens and bilirubin bound to different binding sites of serum albumins

Science.gov (United States)

Orlov, Sergey; Goncharova, Iryna; Urbanová, Marie

Although recent investigations have shown that bilirubin not only has a negative role in the organism but also exhibits significant antimutagenic properties, the mechanisms of interactions between bilirubin and mutagens are not clear. In this study, interaction between bilirubin bound to different binding sites of mammalian serum albumins with structural analogues of the mutagens 2-aminofluorene, 2,7-diaminofluorene and mutagen 2,4,7-trinitrofluorenone were investigated by circular dichroism and absorption spectroscopy. Homological human and bovine serum albumins were used as chiral matrices, which preferentially bind different conformers of bilirubin in the primary binding sites and make it observable by circular dichroism. These molecular systems approximated a real system for the study of mutagens in blood serum. Differences between the interaction of bilirubin bound to primary and to secondary binding sites of serum albumins with mutagens were shown. For bilirubin bound to secondary binding sites with low affinity, partial displacement and the formation of self-associates were observed in all studied mutagens. The associates of bilirubin bound to primary binding sites of serum albumins are formed with 2-aminofluorene and 2,4,7-trinitrofluorenone. It was proposed that 2,7-diaminofluorene does not interact with bilirubin bound to primary sites of human and bovine serum albumins due to the spatial hindrance of the albumins binding domains. The spatial arrangement of the bilirubin bound to serum albumin along with the studied mutagens was modelled using ligand docking, which revealed a possibility of an arrangement of the both bilirubin and 2-aminofluorene and 2,4,7-trinitrofluorenone in the primary binding site of human serum albumin.

Antimutagenic effects of betel leaf extract against the mutagenicity of two tobacco-specific N-nitrosamines.

Science.gov (United States)

Padma, P R; Amonkar, A J; Bhide, S V

1989-03-01

Epidemiological studies have implicated chewing tobacco alone to be more hazardous than chewing tobacco with betel quid. Experimental studies have shown that betel leaf is antimutagenic against standard mutagens like benzo[a]pyrene and dimethylbenz[a]anthracene. Since the tobacco-specific N-nitrosamines (TSNA) are the only carcinogens present in unburnt forms of tobacco, including chewing tobacco, we tested the effect of an extract of betel leaf against the mutagenicity of the two important TSNA, viz., N'-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, using the Ames Salmonella/microsome assay with TA100 +S9 and the in vivo micronucleus test. In both the test systems it was observed that betel leaf extract suppressed the mutagenic effects of both the nitrosamines to a significant extent.

The use of organic solvents in mutagenicity testing.

Science.gov (United States)

Abbondandolo, A; Bonatti, S; Corsi, C; Corti, G; Fiorio, R; Leporini, C; Mazzaccaro, A; Nieri, R; Barale, R; Loprieno, N

1980-10-01

13 organic substances (dimethylsulfoxide, methanol, ethanol, n-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, dl-sec-amyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were considered from the standpoint of their use as solvents for water-insoluble chemicals to be tested for mutagenicity. First, the effect of these solvents on cell survival was studied in the yeast Schizosaccharomyces pombe and in V79 Chinese hamster cells. 8 solvents showing relatively low toxicity on either cell system (dimethylsulfoxide, ethanol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were tested for their effect on aminopyrine demethylase. 4 solvents (ethanol, 1,4-diethylene dioxide, methyl acetate and formamide) showed a more or less pronounced adverse effect on the microsomal enzymic activity. The remaining 4 and methanol (whose effect on aminopyrine demethylase was not testable) were assayed for mutagenicity in S. pombe. They all gave negative results both with and without the post-mitochondrial fraction from mouse liver.

Pollen genetic markers for detection of mutagens in the environment

International Nuclear Information System (INIS)

Nilan, R.A.; Rosichan, J.L.; Arenaz, P.; Hodgdon, A.L.; Kleinhofs, A.

1980-01-01

To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. To be useful for the development of mutagen detection systems proteins should be: (1) activity stainable or immunologically identifiable in the pollen, (2) the products of one to three loci; and (3) gametophytic and nuclear in origin. Several proteins, including alcohol dehydrogenase in maize, which meet these criteria are discussed. The waxy locus in barley and maize which controls starch deposition for pollen screening and mutant detection. Thirty waxy mutant lines, induced by sodium azide and gamma-rays are characterized for spontaneous and induced reversion frequencies, allelism, karyotype, amylose content, and UDPglucose glucosyltransferase (waxy gene product) activity. Twelve mutant alleles are being mapped by recombinant frequencies

Codon cassette mutagenesis: a general method to insert or replace individual codons by using universal mutagenic cassettes.

Science.gov (United States)

Kegler-Ebo, D M; Docktor, C M; DiMaio, D

1994-05-11

We describe codon cassette mutagenesis, a simple method of mutagenesis that uses universal mutagenic cassettes to deposit single codons at specific sites in double-stranded DNA. A target molecule is first constructed that contains a blunt, double-strand break at the site targeted for mutagenesis. A double-stranded mutagenic codon cassette is then inserted at the target site. Each mutagenic codon cassette contains a three base pair direct terminal repeat and two head-to-head recognition sequences for the restriction endonuclease Sapl, an enzyme that cleaves outside of its recognition sequence. The intermediate molecule containing the mutagenic cassette is then digested with Sapl, thereby removing most of the mutagenic cassette, leaving only a three base cohesive overhang that is ligated to generate the final insertion or substitution mutation. A general method for constructing blunt-end target molecules suitable for this approach is also described. Because the mutagenic cassette is excised during this procedure and alters the target only by introducing the desired mutation, the same cassette can be used to introduce a particular codon at all target sites. Each cassette can deposit two different codons, depending on the orientation in which it is inserted into the target molecule. Therefore, a series of eleven cassettes is sufficient to insert all possible amino acids at any constructed target site. Thus codon cassettes are 'off-the-shelf' reagents, and this methodology should be a particularly useful and inexpensive approach for subjecting multiple different positions in a protein sequence to saturation mutagenesis.

Physical‐chemical and microbiological characterization, and mutagenic activity of airborne PM sampled in a biomass‐fueled electrical production facility

DEFF Research Database (Denmark)

Cohn, Corey A.; Lemieux, Christine L.; Long, Alexandra S.

2011-01-01

Biomass combustion is used in heating and electric power generation in many areas of the world. Airborne particulate matter (PM) is released when biomass is brought to a facility, stored, and combusted. Occupational exposure to airborne PM within biomass‐fueled facilities may lead to health probl...... includes PM from biomass combustion as well as internal combustion vehicles, may contribute to an elevated risk of adverse health effects. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.......Biomass combustion is used in heating and electric power generation in many areas of the world. Airborne particulate matter (PM) is released when biomass is brought to a facility, stored, and combusted. Occupational exposure to airborne PM within biomass‐fueled facilities may lead to health...... collected in March was more toxic than PM collected in August. Overall, airborne PM collected from the facility, especially that from the boiler room, were more toxic than PM generated from straw and wood chips. The results suggest that exposure to combustion PM in a biomass‐fueled facility, which likely...

ASCORBIC ACID REDUCTION OF ACTIVE CHLORINE PRIOR TO DETERMINING AMES MUTAGENICITY OF CHLORINATED NATURAL ORGANIC MATTER (NOM)

Science.gov (United States)

Many potable water disinfection byproducts (DBPs) that result from the reaction of natural organic matter (NOM) with oxidizing chlorine are known or suspected to be carcinogenic and mutagenic. The Ames assay is routinely used to assess an overall level of mutagenicity for all com...

Radiation-induced mutagenicity and lethality in Ames tester strains of Salmonella

International Nuclear Information System (INIS)

Isildar, M.; Bakale, G.

1984-01-01

Mutation and killing induced by X radiation and 60 Co γ radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium. Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit significantly higher radiation-induced mutations compared to their plasmidless parent strains TA1535, TA1537, and TA1538, respectively. Among the plasmid-containing strains, TA98 and TA2637 are much more sensitive to the mutagenic action of radiation than is TA100 based on a comparison with their respective spontaneous mutation rates; however, no uniformity was observed in the responses of the strains to the lethal action of ionizing radiation. The following conclusions are consistent with these observations: (1) the standard Ames Salmonella assay correctly identifies ionizing radiation as a mutagenic agent; (2) frameshift-sensitive parent strains are more sensitive to the mutagenic effects of ionizing radiation than is the only strain studied that is sensitive to base-pair substitutions; and (3) enhancement of mutagenesis and survival is related to plasmid-mediated repair of DNA damage induced by ionizing radiation and does not involve damage induced by Cerenkov-generated uv radiation which is negligible for our irradiation conditions

Effect of mutagens on seed germination in chilli (Capsicum annuum L.)

International Nuclear Information System (INIS)

Dhamayanthi, K.P.M.; Reddy, V.R.K.

2002-01-01

Seeds of chilli variety CO-2 (Coimbatore-2) were irradiated with gamma rays ranging from 10 kR to 35 kR at an interval of 5 kR and the effect on seed germination, seedling survival, percent lethality and seedling injury were studied. Lower doses were stimulative, while higher doses had inhibitory effect on seed germination and seedling survival. The highest percentage of seed germination (37.5) and seedling survival (31.3) was recorded at 10 kR as compared to 28 percent of germination and 3.3 percent seedling survival in control. Percent lethality (9.6%) and seedling injury (6.5%) were comparatively low than the lethality percentage and seedling injury of the higher dose treatments. In chemical mutagen treatments, the maximum seed germination (54.5%) and seedling survival (51.2%), seedling lethality (0.97%) and seedling injury (1.37%) were obtained in the treated seeds of EMS at 0.5% concentration followed by 39.5% seed germination and 30.0% seedling survival, seedling lethality (3.8%) and seedling injury (3.06%) of MMS. The stimulative effect of seed germination is more in chemical mutagens than the physical mutagen. There was a proportionate decrease in germination percentage and seedling survival with an increase in dose/concentration of both the chemicals. (author)

Effect of mutagens on the quality characters and disease resistant genes of diploid cotton (Gossypium arboreum L.)

International Nuclear Information System (INIS)

Haidar, S.; Khan, I.A.; Mansoor, S.

2002-01-01

In both M1 and M2 plant height decreased with the increase in dose for both the mutagens. The 15 Krad and 0.15M EMS doses increased 122.7 and 128.3 gm seed cotton yield as compared to control respectively while all other doses of both mutagens decreased the yield of seed cotton. The EMS dose 0.10 M drastically decreased 184 gm seed cotton yield as compared to control. There was no larger effect of both mutagens on GOT % whereas staple length was slightly increased and micronaire value decreased as compared to control for all the doses of both mutagens. It was observed in M2 that mutation dose 10 Krad increased 165.6 gm seed cotton yield as compared to control but slight reduction in GOT % was observed. In M2 GOT were increased 3.5 % with 15 Krad and 3.6 % with EMS 0.10 M as compared to control. There were no larger effects for both mutagens in case of staple length, micronaire and uniformity ratio for all the doses as compared to control. respectively. In both M1 and M2 no plant was observed susceptible to cotton leaf curl virus and bacterial blight diseases of cotton

Nitrite and hypochlorite treatments in determination of the contributions of IQ-type and non-IQ-type heterocyclic amines to the mutagenicities in crude pyrolyzed materials

Energy Technology Data Exchange (ETDEWEB)

Tsuda, M.; Negishi, C.; Makino, R.; Sato, S.; Yamaizumi, Z.; Hirayama, T.; Sugimura, T.

1985-12-01

The mutagenic heterocyclic amines Glu-P-2, MeA alpha C and Phe-P-1, which possess a 2-aminopyridine structure in their molecule (non-IQ-type mutagens), were found to be inactivated by nitrite treatment under acidic conditions, as observed previously with Trp-P-1, Trp-P-2, Glu-P-1 and A alpha C. In contrast, MeIQx, 4,8- and 7,8-DiMeIQx, which were originally isolated from fried beef or heated model mixtures of creatinine, amino acids and glucose, and which have a 2-aminoimidazole moiety in their molecules (IQ-type mutagens), were very resistant to nitrite treatment like IQ and MeIQ. Both types of mutagenic heterocyclic amines were completely inactivated by treatment with hypochlorite. This differential inactivation of mutagenic heterocyclic amines by nitrite and hypochlorite was used in determination of the contributions of IQ-type and non-IQ-type mutagens to the total mutagenicities of various pyrolyzed materials. The percentage contributions of IQ-type mutagens to the mutagenicities of broiled sardine, fried beef, broiled horse mackerel, cigarette smoke condensate and albumin tar were 88, 75, 48, 6 and 4, respectively.

Effectiveness and efficiency of chemical mutagens in cowpea (Vigna ...

African Journals Online (AJOL)

STORAGESEVER

2008-11-19

Nov 19, 2008 ... A study was undertaken in a cowpea (Vigna unguiculata (L.) Walp.) variety CO 6 to assess the efficiency and effectiveness of chemical mutagens; ethyl methane sulphonate (EMS), diethyl sulphate (DES) and sodium azide (SA). EMS treatments were found highly effective than the other chemicals.

Mutagenic potentials of crataegus and laxaricin in human blood ...

African Journals Online (AJOL)

Single cell gel electrophoresis (SCGE) or comet assay was introduced as a microelectrophoretic method for direct visualization of DNA damage in individual cells. Green plants in general contain mutagenic and carcinogenic substances, but there is little information. Due to the increased use and availability of herbal ...

The changeability of Pyricularia oryzae Cav. 1. The action of some mutagenous factors

International Nuclear Information System (INIS)

Voinova, T.M.; Terekhova, V.A.; D'yakov, Yu.T.

1983-01-01

The lethal and mutagenous actions of UV rays, nitrozomethylurea, and nitrosoguanidine in respect to Conidia of rice Pyricularia oryzae Cav. agent have been investigated. It has been found out that low doses of UV-radiation, which are not lethal for a three-cell conidia, increase the intensity of two-cell vegetation. All the investigated mutagens cause a formation of mutants which are deficient according to pigment synthesis white and pink colonies and differ by their reduced growth. Auxotrophic mutants were mainly obtained under the action of nitroso compounds

Atypical Role for PhoU in Mutagenic Break Repair under Stress in Escherichia coli.

Directory of Open Access Journals (Sweden)

Janet L Gibson

Full Text Available Mechanisms of mutagenesis activated by stress responses drive pathogen/host adaptation, antibiotic and anti-fungal-drug resistance, and perhaps much of evolution generally. In Escherichia coli, repair of double-strand breaks (DSBs by homologous recombination is high fidelity in unstressed cells, but switches to a mutagenic mode using error-prone DNA polymerases when the both the SOS and general (σS stress responses are activated. Additionally, the σE response promotes spontaneous DNA breakage that leads to mutagenic break repair (MBR. We identified the regulatory protein PhoU in a genetic screen for functions required for MBR. PhoU negatively regulates the phosphate-transport and utilization (Pho regulon when phosphate is in excess, including the PstB and PstC subunits of the phosphate-specific ABC transporter PstSCAB. Here, we characterize the PhoU mutation-promoting role. First, some mutations that affect phosphate transport and Pho transcriptional regulation decrease mutagenesis. Second, the mutagenesis and regulon-expression phenotypes do not correspond, revealing an apparent new function(s for PhoU. Third, the PhoU mutagenic role is not via activation of the σS, SOS or σE responses, because mutations (or DSBs that restore mutagenesis to cells defective in these stress responses do not restore mutagenesis to phoU cells. Fourth, the mutagenesis defect in phoU-mutant cells is partially restored by deletion of arcA, a gene normally repressed by PhoU, implying that a gene(s repressed by ArcA promotes mutagenic break repair. The data show a new role for PhoU in regulation, and a new regulatory branch of the stress-response signaling web that activates mutagenic break repair in E. coli.

A novel QSAR model of Salmonella mutagenicity and its application in the safety assessment of drug impurities

International Nuclear Information System (INIS)

Valencia, Antoni; Prous, Josep; Mora, Oscar; Sadrieh, Nakissa; Valerio, Luis G.

2013-01-01

As indicated in ICH M7 draft guidance, in silico predictive tools including statistically-based QSARs and expert analysis may be used as a computational assessment for bacterial mutagenicity for the qualification of impurities in pharmaceuticals. To address this need, we developed and validated a QSAR model to predict Salmonella t. mutagenicity (Ames assay outcome) of pharmaceutical impurities using Prous Institute's Symmetry℠, a new in silico solution for drug discovery and toxicity screening, and the Mold2 molecular descriptor package (FDA/NCTR). Data was sourced from public benchmark databases with known Ames assay mutagenicity outcomes for 7300 chemicals (57% mutagens). Of these data, 90% was used to train the model and the remaining 10% was set aside as a holdout set for validation. The model's applicability to drug impurities was tested using a FDA/CDER database of 951 structures, of which 94% were found within the model's applicability domain. The predictive performance of the model is acceptable for supporting regulatory decision-making with 84 ± 1% sensitivity, 81 ± 1% specificity, 83 ± 1% concordance and 79 ± 1% negative predictivity based on internal cross-validation, while the holdout dataset yielded 83% sensitivity, 77% specificity, 80% concordance and 78% negative predictivity. Given the importance of having confidence in negative predictions, an additional external validation of the model was also carried out, using marketed drugs known to be Ames-negative, and obtained 98% coverage and 81% specificity. Additionally, Ames mutagenicity data from FDA/CFSAN was used to create another data set of 1535 chemicals for external validation of the model, yielding 98% coverage, 73% sensitivity, 86% specificity, 81% concordance and 84% negative predictivity. - Highlights: • A new in silico QSAR model to predict Ames mutagenicity is described. • The model is extensively validated with chemicals from the FDA and the public domain. • Validation tests

Mutagenic activities of metal compounds in bacteria

Energy Technology Data Exchange (ETDEWEB)

Nishioka, H

1975-01-01

Environmental contaminations by certain metal compounds are bringing about serious problems to human health, including genetic hazards. It has been reported that some compounds of iron, manganese and mercury induce point mutations in microorganisms. Also it has been observed that those of aluminum, antimony, arsenic, cadmium, lead and tellurium cause chromosome aberrations in plants, insects and cultured human cells. The mechanism of mutation induction by these metals remains, however, still obscure. For screening of chemical mutagens, Kada et al, recently developed a simple and efficient method named rec-assay by observing differential growth sensitivities to drugs in wild and recombination-deficient strains of Bacillus subtilis. When a chemical is more inhibitory for Rec/sup -/ than for Rec/sup +/ cells, it is reasonable to suspect mutagenicity based on its DNA-damaging capacity. In the present report, 56 metal compounds were tested by the rec-assay. Compounds showing positive results in the assay such as potassium dichromate (K/sub 2/Cr/sub 2/O/sub 7/), ammonium molybdate ((NH/sub 4/)/sub 6/Mo/sub 7/O/sub 24/) and sodium arsenite (NaAsO/sub 2/) were then examined as to their capacities to induce reversions in E. coli Trp/sup -/ strains possessing different DNA repair pathways. 11 references, 3 tables.

On the mutagenicity of homologous recombination and double-strand break repair in bacteriophage.

Science.gov (United States)

Shcherbakov, Victor P; Plugina, Lidiya; Shcherbakova, Tamara; Sizova, Svetlana; Kudryashova, Elena

2011-01-02

The double-strand break (DSB) repair via homologous recombination is generally construed as a high-fidelity process. However, some molecular genetic observations show that the recombination and the recombinational DSB repair may be mutagenic and even highly mutagenic. Here we developed an effective and precise method for studying the fidelity of DSB repair in vivo by combining DSBs produced site-specifically by the SegC endonuclease with the famous advantages of the recombination analysis of bacteriophage T4 rII mutants. The method is based on the comparison of the rate of reversion of rII mutation in the presence and in the absence of a DSB repair event initiated in the proximity of the mutation. We observed that DSB repair may moderately (up to 6-fold) increase the apparent reversion frequency, the effect of being dependent on the mutation structure. We also studied the effect of the T4 recombinase deficiency (amber mutation in the uvsX gene) on the fidelity of DSB repair. We observed that DSBs are still repaired via homologous recombination in the uvsX mutants, and the apparent fidelity of this repair is higher than that seen in the wild-type background. The mutator effect of the DSB repair may look unexpected given that most of the normal DNA synthesis in bacteriophage T4 is performed via a recombination-dependent replication (RDR) pathway, which is thought to be indistinguishable from DSB repair. There are three possible explanations for the observed mutagenicity of DSB repair: (1) the origin-dependent (early) DNA replication may be more accurate than the RDR; (2) the step of replication initiation may be more mutagenic than the process of elongation; and (3) the apparent mutagenicity may just reflect some non-randomness in the pool of replicating DNA, i.e., preferential replication of the sequences already involved in replication. We discuss the DSB repair pathway in the absence of UvsX recombinase. Copyright © 2010 Elsevier B.V. All rights reserved.

Bystander effect of alpha-particle irradiation on mutagenicity and its associated mechanism

International Nuclear Information System (INIS)

Lu Ying; Yang Zhihua; Cao Zhenshan; Fan Feiyue; Zhu Maoxiang

2004-01-01

The work is to investigate α-particle irradiation-induced bystander effects on the mutagenicity in human chromosome 11 in the human-hamster hybrid (A L cells) and its possible mechanism. A L cells were used for assaying mutation rates of human chromosome 11 through screening mutants in the presence of anti-CD59 surface antigen antibody (S1) and complement. A grid was interposed between α-particle source and the cells being irradiated, so as to fix proportion of the irradiated cells (15%) and the bystander effects on the mutagenicity were detected. Free radical scavenger DMSO and intercellular communication inhibitor Lindane were selected to investigate the potential mechanism of α-particle induced bystander effect. There was clear dose-dependent relationship between mutation rate and the dose of alpha particle radiation. However, the mutant fractions of cell population shielded by the grid in α-particle irradiation system were much higher than the expected levels of irradiated cells. Lindane, but not DMSO, could obviously decrease this bystander effect induced by α-particle irradiation. Alpha-particle irradiation can induce bystander effect on the mutagenicity, in which intercellular communication may play important roles

Improvement of mutation rate and reduction of somatic effects by double treatment of chemical mutagens in barley

International Nuclear Information System (INIS)

Koo, B.C.; Maluszynski, M.

1996-01-01

Mutation techniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties; Dema, Grosso were treated with two types of mutagens; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN 3 ) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M 1 seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0 mM MNH (0.5 mM MNH + 0.5 mM MNH), for example, were less than one of plants of single treatment of 1.0 mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M 1 plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M 2 seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects

Effects of chemical and physical mutagens on the frequency of a large genetic duplication in Salmonella typhimurium. I

International Nuclear Information System (INIS)

Hoffman, G.R.; Morgan, R.W.

1978-01-01

In Salmonella typhimurium a simple selection has been described to detect bacteria that are merodiploid for almost one-third of the chromosome. The selective procedure is based upon improved utilization of L-malate as the sole carbon source in merodiploid strains. The spontaneous frequency of the duplication in haploid strains is approximately 10 -4 per cell plated. Following the exposure of a haploid strain to mutagenic agents, there is a dose-dependent increase in the duplication frequency above the spontaneous level. In this paper the authors describe the induction of genetic duplications in Salmonella typhimurium by X-rays, ultraviolet light (UV), ethyl methanesulfonate (EMS), nitrous acid, and the azaacridine half mustard, ICR-372. (Auth.)

Absence of Mutagenicity in Three Nigerian Medicinal Plants ...

African Journals Online (AJOL)

Erah

of the medicinal plant trade in the region [2]. One of the basic criteria set by World Health. Organization (WHO) for the use of herbs as medicines is that they should be shown to be non-toxic [3,4]. Bacterial reverse mutation assay (Ames test) was used in this work to evaluate the mutagenic potential of the methanolic extracts ...

Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

Science.gov (United States)

Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

1994-01-01

The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

Isolation and characterization of X-linked mutants of Drosophila melanogaster which are sensitive to mutagens

International Nuclear Information System (INIS)

Boyd, J.B.; Golino, M.D.; Nguyen, T.D.; Green, M.M.

1976-01-01

Thirteen X-linked mutants have been isolated in Drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41. Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the X-chromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)101 locus, two to mus(1)102, two to mus(1)103, and one each to mus(1)104, mus(1)105, and mus(1)106. Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)101 and mus(1)102 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(1)101, and mus(1)104 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2-acetylaminofluorene and a deficiency in post-replication repair. Only the mei-41 mutants are hypersensitive to uv radiation, although several of the mutants exhibit sensitivity to γ-rays. Semidominance is observed in female larvae of the mei-41, mus(1)104, and mus(1)103 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast

Prophage induction, mutagenesis, and cell survival of Ames' mutagen tester strains after 8-methoxypsoralen plus ultraviolet light-A

Energy Technology Data Exchange (ETDEWEB)

Wheeler, L.A.; DeMeo, M. (California Univ., Los Angeles (USA)); Lowe, N. (Combined UCLA-WADSWORTH Dermatology Program, Los Angeles, CA (USA))

1983-10-01

8-methoxypsoralen (8-MOP) is not detected as a mutagen in the standard Ames test either in the presence or absence of S9-mix and/or ultraviolet light-A (320-400 nm). The Ames strains have been shown to harbor bacteriophages that are inducible by carcinogens and mutagens. Psoralen plus UVA (PUVA) was found to be a potent prophage inducing treatment. Induction was observed in TA1535, TA1538, TA98, TA100, TA1978 and TA1975 with 8-MOP and UVA. PUVA is a potent bactericidal treatment at concentrations of 8-MOP above 0.5 ..mu..g/ml and 2.5 kJ/m/sup 2/ in tester strains TA1535, TA1538, TA98 and TA100. PUVA is known to be bactericidal, but the cytotoxicity observed in the present study was unique in that the frameshift tester strains (TA1538 and TA98) were more sensitive to the lethal effects of PUVA than the base pair tester strains (TA1535 and TA100). The differential cytotoxicity in such closely related strains led to the examination of some of the strains from which the Ames strains were derived. It is postulated that TA1535 retains a DNA repair function that is lost by TA1538 during the selection for uvrB deficient strains.

Studies on chemical and physical mutagens' induced polygenic variability in mungbean (Vigna radiata (L.) Wilczek)

International Nuclear Information System (INIS)

Sangwan, H.P.S.; Singh, M.P.

1990-01-01

Full text: Pulses used to be and still are cultivated on marginal lands under poor management conditions which result in low production. Genotypes which could respond to better management have been eliminated by past selection. It is, therefore, difficult and challenging to breed high yielding varieties in pulse crops with the limited genetic variability available. Induced mutations could supplement this variability. Extensive studies on genotype-mutagen interaction were undertaken with six varieties of mungbean having contrasting seed characteristics, morphological traits and genetic backgrounds. Each variety was treated with 300 Gy and 600 Gy of gamma rays, 0.1 and 0.5% of EMS, and 0.1 and 0.05 of SA. Dry seeds, water soaked and phosphate buffer soaked seeds served as controls. The following observations were made: differential response of varieties to mutagen treatments - irrespective of the variety or the characters; gamma-rays proved to be more effective than chemical mutagens; mutagenic treatments resulted in development of early maturing mutants that can fit well in multiple cropping systems particularly in raising a mung crop after the wheat harvest. The fact that some mutants were detected in M 4 with significant increase in yield and marginal improvement in protein content generation suggests the possibility of improving both characters provided a large population is screened. (author)

Mutagenicity and antimutagenicity of Salacia crassifolia (mart. Ex. Schult. G. Don. evaluated by Ames test

Directory of Open Access Journals (Sweden)

C. C. Carneiro

2017-09-01

Full Text Available Abstract Salacia crassifolia (Mart. Ex. Schult. G. Don. is a bush which belongs to Celastraceae family and occurs specially in Brazilian Cerrado. Its leaves, stem, seeds and fruits are popularly used for several medicinal purposes, such as antitumoral, antirheumatic, anti-inflammatory and antimicrobial. In this study, the mutagenic and antimutagenic activities of S. crassifolia stem bark fractions (hexane, ethyl acetate and hydroalcoholic were evaluated by the Ames mutagenicity assay in Salmonella typhimurium TA98 and TA100 strains. By the obtained results, all S. crassifolia fractions did not significantly increase the number of prototrophic revertants for histidine (His+ in both S. typhimurium strains tested (p > 0.05, suggesting absence of mutagenicity. Regarding antimutagenicity, the fractions ethyl acetate and hydroalcoholic significantly decreased the number of His+ revertants colonies induced by positive control for strain TA98 (p < 0.05, demonstrating protection against mutagenicity induced by 4-nitroquinolile1-oxide, whereas the hexane fraction did not show antimutagenic effect in this strain. In the TA100 strain, all fractions of S. crassifolia protected DNA against the harmful action of sodium azide, and the hexane fraction exhibited the greatest protection in this work. Thus, it’s possible conclude that the fractions of S. crassifolia tested in this study could be used in chemoprevention.

Interactive lethal and mutagenic effects of ultraviolet light and bleomycin in yeast: synergism or antagonism?

Science.gov (United States)

Lillo, O L; Severgnini, A A; Nunes, E M

1997-11-01

The mutagenic interactions of ultraviolet light and bleomycin in haploid populations of Saccharomyces cerevisiae were analyzed. Survival and mutation frequency as a function of different bleomycin concentrations after one conditioning dose of UV radiation were determined. Furthermore, corresponding interaction functions and sensitization factors were calculated. A synergistic interaction between UV light and bleomycin was shown for both lethal and mutagenic events when the cells were in nutrient broth during the treatments. Conversely, the interaction between UV light and bleomycin was antagonistic when the cells were in deionized water during the treatment. The magnitude of lethal and mutagenic interactions depends on dose, and thus presumably on the number of lesions. The observed interactions between UV light and bleomycin suggest that the mechanism that is most likely involved is the induction of repair systems with different error probabilities during the delay of cell division.

Antioxidant, mutagenic and antimutagenic activities of an aqueous extract of Limoniastrum guyonianum gall.

Science.gov (United States)

Krifa, Mounira; Bouhlel, Ines; Skandrani, Ines; Chekir-Ghedira, Leila; Ghedira, Kamel

2014-01-01

An aqueous extract of Limoniastrum guyonianum gall (G extract) was tested on Salmonella typhimurium to assess its mutagenic and antimutagenic effects. This extract showed no mutagenicity when tested with S. typhimurium strain TA104 either with or without exogenous metabolic activation mixture (S9), whereas our findings revealed that the aqueous gall extract induced a mutagenic effect in S. typhimurium TA1538 when tested in the presence, as well as in the absence, of S9 activation mixture at the concentration of 500 µg/mL. Thus, the same concentration produced a mutagenic effect, when incubated with S. typhimurium TA100 in the presence of metabolic activation mixture. In contrast, our results showed a weak antimutagenic potential of the same extract against sodium azide in the presence of S. typhimurium TA100 and S. typhimurium TA1538 without metabolic activation (S9), whereas, in the presence of S. typhimurium TA104, we obtained a significant inhibition percentage (76.39%) toward 3.25 µg/plate of methylmethanesulfonate. Antimutagenicity against aflatoxin B1, 4-nitro-o-phenylene-diamine and 2-aminoanthracène was significant, with an inhibition percentage of, respectively, 70.63, 99.3 and 63.37% in the presence of, respectively, S. typhimurium TA100, S. typhimurium TA1538 and S. typhimurium TA104 strains at a concentration of 250 µg/plate after metabolic activation (S9). Antioxidant capacity of the tested extract was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the nonenzymatic (2,2-diphenyl-1-picrylhydrazyl) system. G extract exhibited high antioxidant activity.

Biological effects from electromagnetic fields: Research progress and exposure measurements

International Nuclear Information System (INIS)

Mauro, F.; Lovisolo, G.A.; Raganella, L.

1992-01-01

Although it is commonly accepted that exposure to high levels of electromagnetic, micro- and radiofrequency waves produces harmful effects to the health of man, the formulation of exposure limits is still an open process and dependent upon the evolving level of knowledge in this field. This paper surveys the current level of knowledge gained through 'in vitro' and 'in vivo' radiological and epidemiological studies on different types of electromagnetic radiation derived effects - chromosomal, mutagenic, carcinogenic. It then reviews efforts by international organizations, e. g., the International Radiation Protection Association, to establish exposure limits for radiofrequency electromagnetic fields. Brief notes are given on the electromagnetic radiation monitoring campaign being performed by public health authorities in the Lazio Region of Italy

Radiosensitization, mutagenicity, and toxicity of Escherichia coli by several nitrofurans and nitroimidazoles. [X radiation

Energy Technology Data Exchange (ETDEWEB)

Chessin, H.; McLaughlin, T.; Mroczkowski, Z.; Rupp, W.D.; Low, K.B.

1978-08-01

Representative nitrofurans (nitrofurantoin, nifuroxime, NF-167, NF-269) and nitroimidazoles (metronidazole, misonidazole) were found to sensitize hypoxic RecA/sup -/ Escherichia coli cells to X irradiation. These compounds were also mutagenic to E. coli using a UvrA/sup -/ strain as a test system, and toxic at high concentrations, using several strains differing in their repair capacity. However, the relative degrees of radiosensitization, mutagenicity, and toxicity, for the various compounds, were not simply correlated, suggesting that potential radiosensitizers with fewer side effects could be screened using bacteria.

Micronuclei frequency in children exposed to environmental mutagens: a review

DEFF Research Database (Denmark)

Neri, Monica; Fucic, Aleksandra; Knudsen, Lisbeth E

2003-01-01

studies in children are a promising field, since because of evident differences in the uptake, metabolism, distribution and excretion of mutagens this population seems to be more susceptible than adults. Further, the effect of major confounders such as cigarettes smoking, occupation, life...

A novel QSAR model of Salmonella mutagenicity and its application in the safety assessment of drug impurities

Energy Technology Data Exchange (ETDEWEB)

Valencia, Antoni; Prous, Josep; Mora, Oscar [Prous Institute for Biomedical Research, Rambla de Catalunya, 135, 3-2, Barcelona 08008 (Spain); Sadrieh, Nakissa [Office of Pharmaceutical Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993-0002 (United States); Valerio, Luis G., E-mail: luis.valerio@fda.hhs.gov [Office of Pharmaceutical Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993-0002 (United States)

2013-12-15

As indicated in ICH M7 draft guidance, in silico predictive tools including statistically-based QSARs and expert analysis may be used as a computational assessment for bacterial mutagenicity for the qualification of impurities in pharmaceuticals. To address this need, we developed and validated a QSAR model to predict Salmonella t. mutagenicity (Ames assay outcome) of pharmaceutical impurities using Prous Institute's Symmetry℠, a new in silico solution for drug discovery and toxicity screening, and the Mold2 molecular descriptor package (FDA/NCTR). Data was sourced from public benchmark databases with known Ames assay mutagenicity outcomes for 7300 chemicals (57% mutagens). Of these data, 90% was used to train the model and the remaining 10% was set aside as a holdout set for validation. The model's applicability to drug impurities was tested using a FDA/CDER database of 951 structures, of which 94% were found within the model's applicability domain. The predictive performance of the model is acceptable for supporting regulatory decision-making with 84 ± 1% sensitivity, 81 ± 1% specificity, 83 ± 1% concordance and 79 ± 1% negative predictivity based on internal cross-validation, while the holdout dataset yielded 83% sensitivity, 77% specificity, 80% concordance and 78% negative predictivity. Given the importance of having confidence in negative predictions, an additional external validation of the model was also carried out, using marketed drugs known to be Ames-negative, and obtained 98% coverage and 81% specificity. Additionally, Ames mutagenicity data from FDA/CFSAN was used to create another data set of 1535 chemicals for external validation of the model, yielding 98% coverage, 73% sensitivity, 86% specificity, 81% concordance and 84% negative predictivity. - Highlights: • A new in silico QSAR model to predict Ames mutagenicity is described. • The model is extensively validated with chemicals from the FDA and the public domain. �

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters.

Science.gov (United States)

Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

2015-03-31

A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.

MUTAGENICITY OF NITRITE-TREATED AQUEOUS EXTRACT OF 'PIPER BETLE'; L

Science.gov (United States)

Betel quid is chewed as a masticatory material by people in certain areas of Asia. The quid chewing has been related to oral cancer by epidemiological study. The mutagenic components in the aqueous extracts of betel quid ingredients were studied. Only nitrite-treated aqueous extr...

Mutagenicity of diesel exhaust soot dispersed in phospholipid surfactants

Energy Technology Data Exchange (ETDEWEB)

Wallace, W.; Keane, M.; Xing, S.; Harrison, J.; Gautam, M.; Ong, T.

1994-06-01

Organics extractable from respirable diesel exhaust soot particles by organic solvents have been known for some time to be direct acting frameshift mutagens in the Ames Salmonella typhimurium histidine reversion assay. Upon deposition in a pulmonary alveolus or respiratory bronchiole, respirable diesel soot particles will contact first the hypophase which is coated by and laden with surfactants. To model interactions of soot and pulmonary surfactant, the authors dispersed soots in vitro in the primary phospholipid pulmonary surfactant dipalmitoyl glycerophosphorylcholine (lecithin) (DPL) in physiological saline. They have shown that diesel soots dispersed in lecithin surfactant can express mutagenic activity, in the Ames assay system using S. typhimurium TA98, comparable to that expressed by equal amounts of soot extracted by dichloromethane/dimethylsulfoxide (DCM/DMSO). Here the authors report additional data on the same system using additional exhaust soots and also using two other phospholipids, dipalmitoyl glycerophosphoryl ethanolamine (DPPE), and dipalmitoyl phosphatidic acid (DPPA), with different ionic character hydrophilic moieties. A preliminary study of the surfactant dispersed soot in an eucaryotic cell test system also is reported.

Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

Science.gov (United States)

Pratt, J. R.

1981-01-01

Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

Chemical characterization and cytotoxic, genotoxic, and mutagenic properties of Baccharis trinervis (Lam, Persoon) from Colombia and Brazil.

Science.gov (United States)

Jaramillo-García, Victoria; Trindade, Cristiano; Lima, Elisiane; Guecheva, Temenouga N; Villela, Izabel; Martinez-Lopez, Wilner; Corrêa, Dione S; Ferraz, Alexandre de B F; Moura, Sidnei; Sosa, Milton Quintana; Da Silva, Juliana; Henriques, João Antônio Pegas

2018-03-01

Baccharis trinervis (Lam, Persoon) leaves are used in the traditional medicine for the treatment of high fevers, edema, inflammation, sores and muscle cramps, snakebites and as antiseptic. To investigate the cytotoxic, genotoxic, and mutagenic effects of extracts and fractions of B. trinervis from Brazil and Colombia in Chinese Hamster Ovary (CHO) cells, and to examine the mutagenic activity in Salmonella typhimurium. Aqueous extracts (AE) of aerial parts of B. trinervis from Brazil (B) and Colombia (C) were fractioned in ethyl acetate fraction (EAF), butanol extract (BF), and aqueous residue fraction (ARF). Qualitative chemical screening and determination of total flavonoid content were made. Identification of chemical constituents was performed by High Performance Liquid Chromatography (HPLC) and High Resolution Mass Spectrometry (HRMS). For the in vitro tests, CHO cells were treated for 3h with extracts and fractions. The cytotoxic activity was evaluated by clonal survival and 3-(4.5-dimethylthiazole-2-yl)-2.5-biphenyl tetrazolium bromide reduction assay (MTT). Genotoxic and mutagenic effects were evaluated by the alkaline comet assay and Cytokinesis-blockage micronucleus test (CBMN), respectively. Additionally, Salmonella/microsome assay was carried out to determinate the mutagenic effects in EAF from Brazil and Colombia. Phytochemical analyses indicated the presence of saponins and flavonoids. AE and EAF were the samples with the highest quantity of total flavonoids. HPLC showed the presence of luteolin only in AEC, and caffeic acid, ellagic acid, rosmarinic acid, and rutin were identified in AEB and AEC (AEC>AEB). The HRMS in positive mode of EAFB and EAFC showed presence of two carboxylic acids, coumarin, and two terpenoids. In addition, were identified one terpenoid and two carboxylic acids in AE, BF and ARF of B. trinervis from both countries in negative mode. Dose-dependent cytotoxic effects were observed in CHO cells treated with B. trinervis extracts

Toxicological evaluation of complex industrial wastes: Implications for exposure assessment

Energy Technology Data Exchange (ETDEWEB)

DeMarini, D.M.; Gallagher, J.E.; Houk, V.S.; Simmons, J.E.

1990-07-01

We evaluated a variety of short-term bioassays to construct a battery of tests that could be used for assessing the biological effects of potentially hazardous complex industrial wastes. Ten samples were studied for hepatotoxicity; these samples and an additional five were studied for mutagenicity. Although the data are limited to these samples, the results suggest that the Salmonella assay (strain TA98) or a prophage-induction assay (both in the presence of S9) in combination with determination of relative liver weight and levels of a set of serum enzymes in rats may provide a battery of tests suitable to characterize complex industrial wastes for mutagenic and hepatotoxic potential. The biological activities exhibited by the wastes were not readily predicted by the chemical profiles of the wastes, emphasizing the importance of characterizing potentially hazardous complex industrial wastes by both chemical and biological means. DNA from liver, lung, and bladder of rats exposed to some of the wastes was analyzed by the 32P-postlabeling technique for the presence of DNA adducts. A waste that produced mutagenic urine produced a DNA adduct in bladder DNA. The implications of this approach for assessment of exposure to complex hazardous waste mixtures are discussed.

Induction of mutagenized tomato populations for investigation on agronomic traits and mutant phenotyping

Directory of Open Access Journals (Sweden)

Rafiul Amin Laskar

2018-01-01

Full Text Available Global demand for tomato production increased tremendously due to its diverse utility in raw, cooked and processed form of food. This necessitates the continued supply of highly nutritious and better yielding improved cultivars to the producers, considering the rapid changing agro-climatic condition. In this study, induced mutant tomato populations of widely recommended tomato genotype Arka Vikas (Sel-22 were generated using chemical mutagen ethyl methane sulfonate (EMS, hydrazine hydrates (HZ and their combined treatments. In the in vitro study, a gradual reduction in germination percentage and seedling height occurred with the increasing concentrations of mutagens. Combination of EMS and HZ caused maximum biological inhibition followed by EMS and HZ treatments alone in M1 generation. The rate of survival and fertility in M1 plants of tomato was found highly affected due to mutagenic treatment, in which sensitivity toward combined treatment was found highest followed by EMS and HZ. Inspection on induced phenotypic variations in individual plants of M2 population resulted in identification and isolation of wide range of mutants with altered phenotypes. Highest mutation frequency was resulted by combined mutagens followed by the EMS and HZ treatment. Agronomic trait analyses showed intra and inter treatment variations in three quantitative traits (Plant height, fertile branch per plant and fruits per plant of M2 mutagenized population. Assessment on rate of mutant recovery in M2 population showed highest mutant recovery is possible with combination treatments and then 0.02% HZ followed by 0.02% EMS. In the present study, phenotyping of the mutants revealed that vegetative organs (‘plant size’, ‘plant habit’ and ‘leaf morphology’ was the most sensitive category (69.33% to which most of the mutant belongs, followed by ‘fruit color and size’ (20.27% and ‘germination’ (9.79%. Comparative investigation on number of mutants and

Safety Evaluation of Turmeric Polysaccharide Extract: Assessment of Mutagenicity and Acute Oral Toxicity

Science.gov (United States)

Velusami, Chandrasekaran Chinampudur; Boddapati, Srinivasa Rao; Hongasandra Srinivasa, Srikanth; Richard, Edwin Jothie; Balasubramanian, Murali

2013-01-01

Curcuma longa Linn. (Zingiberaceae) commonly known as turmeric has long been used for centuries as a spice and household remedy. The present study was carried out to assess the possible mutagenic potential and acute oral toxicity of polysaccharide extract of turmeric rhizome (NR-INF-02) using standard tests. The standard battery of in vitro genotoxicity tests, bacterial reverse mutation test (BRMT), chromosome aberration (CA), and micronucleus (MN) tests were employed to assess the possible mutagenic activity of NR-INF-02 (Turmacin). The results showed no mutagenic effect with NR-INF-02 up to a dose of 5000 µg/mL in BRMT. The results on CA and MN tests revealed the non clastogenic activity of NR-INF-02 in a dose range of 250.36 to 2500 µg/mL with and without metabolic activation (S9). In acute oral toxicity study, NR-INF-02 was found to be safe up to 5 g/kg body weight in Wistar rats. Overall, results indicated that polysaccharide extract of C. longa was found to be genotoxically safe and also exhibited maximum tolerable dose of more than 5 g/kg rat body weight. PMID:24455673

28. Annual Meeting of the European Environmental Mutagen Society

International Nuclear Information System (INIS)

1998-09-01

The 28 th Annual Meeting of the European Environmental Mutagen Society took place in Salzburg from September 7 th till September 11 th , 1998. A lot of presentations also dealt with many radiation effects on cells, chromosomal aberrations and genetic effects caused by radioactive irradiation. In vivo and in vitro experiments concerning radiation injuries and carcinomas are analyzed. (Cecil)

Mutagenicity and estrogenicity of raw water and drinking water in an industrialized city in the Yangtze River Delta.

Science.gov (United States)

Xiao, Sanhua; Lv, Xuemin; Zeng, Yifan; Jin, Tao; Luo, Lan; Zhang, Binbin; Zhang, Gang; Wang, Yanhui; Feng, Lin; Zhu, Yuan; Tang, Fei

2017-10-01

Public concern was aroused by frequently reported water pollution incidents in Taihu Lake and the Yangtze River. The pollution also caught and sustained the attention of the scientific community. From 2010 to 2016, raw water and drinking water samples were continually collected at Waterworks A and B (Taihu Lake) and Waterworks C (Yangtze River). The non-volatile organic pollutants in the water samples were extracted by solid phase extraction. Ames tests and yeast estrogen screen (YES) assays were conducted to evaluate the respective mutagenic and estrogenic effects. Water samples from the Yangtze River-based Waterworks C possessed higher mutagenicity than those from Taihu Lake-based Waterworks A (P＜0.001) and Waterworks B (P = 0.026). Water treatment enhanced the direct mutagenicity (P = 0.022), and weakened the estrogenicity of the raw water (P＜0.001) with a median removal rate of 100%. In fact, very few of the finished samples showed estrogenic activity. Raw water samples from Waterworks A showed weaker estrogenicity than those from Waterworks B (P = 0.034) and Waterworks C (P = 0.006). In summary, mutagenic effects in drinking water and estrogenic effects in raw water merited sustained attention. The Yangtze River was more seriously polluted by mutagenic and estrogenic chemicals than Taihu Lake was. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of mutagens on enzymes of germinating seeds of cotton (Gossypium hirsutum L.)

International Nuclear Information System (INIS)

Muthusamy, A.; Jayabalan, N.; Juliana, B.

2000-01-01

The activities of the enzymes amylases, protease and phosphatases were studied in cotton during germination. The seeds were treated with 100-500 Gy of gamma rays, 10-50 mM of EMS, CA and SA in two cultivated varieties viz.. MCU 5 and MCU 11. Activity pattern of amylases, protease and phosphatases in treated seeds were significantly altered from controls. The alteration were positively correlated with increasing dose/concentration of mutagens up to 300 Gy of gamma rays and 30 mM of EMS, CA and SA. The present study pave the ways to discuss the importance of the enzymes and mutagens in germination of cotton seeds. (author)

Molecular Modeling of the Major DNA Adduct Formed from Food Mutagen Ochratoxin A in NarI Two-Base Deletion Duplexes: Impact of Sequence Context and Adduct Ionization on Conformational Preference and Mutagenicity.

Science.gov (United States)

Kathuria, Preetleen; Sharma, Purshotam; Manderville, Richard A; Wetmore, Stacey D

2017-08-21

Exposure to ochratoxin A (OTA), a possible human carcinogen, leads to many different DNA mutations. As a first step toward understanding the structural basis of OTA-induced mutagenicity, the present work uses a robust computational approach and a slipped mutagenic intermediate model previously studied for C 8 -dG aromatic amine adducts to analyze the conformational features of postreplication two-base deletion DNA duplexes containing OT-dG, the major OTA lesion at the C 8 position of guanine. Specifically, a total of 960 ns of molecular dynamics simulations (excluding trial simulations) were carried out on four OT-dG ionization states in three sequence contexts within oligomers containing the NarI recognition sequence, a known hotspot for deletion mutations induced by related adducts formed from known carcinogens. Our results indicate that the structural properties and relative stability of the competing "major groove" and "stacked" conformations of OTA adducted two-base deletion duplexes depend on both the OTA ionization state and the sequence context, mainly due to conformation-dependent deviations in discrete local (hydrogen-bonding and stacking) interactions at the lesion site, as well as DNA bending. When the structural characteristics of the OT-dG adducted two-base deletion duplexes are compared to those associated with previously studied C 8 -dG adducts, a greater understanding of the effects of the nucleobase-carcinogen linkage, and size of the carcinogenic moiety on the conformational preferences of damaged DNA is obtained. Most importantly, our work predicts key structural features for OT-dG-adducted deletion DNA duplexes, which in turn allow us to develop hypotheses regarding OT-dG replication outcomes. Thus, our computational results are valuable for the design and interpretation of future biochemical studies on the potentially carcinogenic OT-dG lesion.

Studies on chlorophyll and viable mutations in green gram (Vigna radiata L. Wilczek) II: Response to mutagen

Energy Technology Data Exchange (ETDEWEB)

Krishnaswami, S; Rathinam, M [Tamil Nadu Agricultural Univ., Coimbatore (India). Dept. of Agricultural Botany

1980-09-01

The frequency and spectrum of chlorophyll and viable mutations in relation to type and dose of mutagen and cluster progenies were studied in four green gram cultivars viz., Kopergaon, Pusa Baisakhi, L. 24/2 and Sel. 122 subjected to two levels of EMS and gamma irradiation, severally and in conjunction. While chlorophyll mutations did not vary with the mutagen dose, viable mutations exhibited a direct relationship. Combinations of the mutagens were more effective in mutation induction. While no difference was manifested between the cluster families in respect of chlorophyll mutations, progenies of the second cluster recorded less viable mutations than either the first or the third. Viridis and xanthoviridis among chlorophyll mutations, and those affecting plant duration and stature among viable were more predominant.

Evaluation of genotoxic and anti-mutagenic properties of cleistanthin A and cleistanthoside A tetraacetate.

Science.gov (United States)

Himakoun, Lakana; Tuchinda, Patoomratana; Puchadapirom, Pranom; Tammasakchai, Ratigon; Leardkamolkarn, Vijittra

2011-01-01

Cleistanthin A (CleinA) and cleistanthoside A (CleisA) isolated from plant Phyllanthus taxodiifolius Beille have previously shown potent anticancer effects. To promote their medicinal benefits, CleisA was modified to cleistanthoside A tetraacetate (CleisTA) and evaluated for genotoxic and anti-mutagenic properties in comparison with CleinA. Both compounds showed no significant mutagenic activity to S. typhimulium bacteria and no cytotoxic effect to normal mammalian cells. The non genotoxic effect of CleinA was further confirmed by un-alteration of cytokinesis-block proliferation index (CBPI) and micronucleus (MN) frequency assays in Chinese hamster lung fibroblast (V79) cells, and of CleisTA was confirmed by un-changes of human peripheral blood lymphocytes (HPBL) chromosomal structure assay. Moreover, the metabolic form of CleinA efficiently demonstrated cytostasis effect to V79 cell and prevented mutagen induced Salmonella TA98 and TA100 reversion, whereas both metabolic and non-metabolic forms of CleisTA reduced HPBL mitotic index (%M.I) in a concentration-dependent relationship. The results support CleinA and CleisTA as the new lead compounds for anti-cancer drug development.

Toxicity, mutagenicity, and behavioral effects of β-CIT, a ligand for dopamine transporter exploration by SPECT

International Nuclear Information System (INIS)

Emond, P.; Farde, L.; Chalon, S.; Belzung, C.; Mauclaire, V.; Chiron, J. P.; Halldin, C.; Besnard, J.C.; Guilloteau, D.

1998-01-01

The cocaine analog β-CIT is one of the most used compounds for SPET examination of the dopamine transporter in drug abuse and Parkinson's disease. However, the toxicity of this agent has not yet been studied. We report here acute toxicity, mutagenicity, and effect on locomotor activity of β-CIT. Acute toxicity experiments were performed in mice and rats. The LD50 values were about 20 mg and 5 mg for mice and rats, respectively. There was no sex difference. The mutagenicity was evaluated using the Ames' test. No mutagenic effect was observed for β-CIT. Effects on locomotor activity were measured in mice using the open-field test. β-CIT increased locomotion (+65%) when injected at a dose of 0.312 mg/kg; the maximal increase (+205%) was observed at a dose of 1.25 mg/kg; at higher doses, the effect was decreased slightly. These pharmacological findings are in agreement with an inhibitory effect of β-CIT at the dopamine transporter. We conclude that with no mutagenic effects and LD50 more than 6 orders of magnitude higher than the routinely used doses in PET or SPET, it can be assumed that β-CIT can be safely used as a radioligand in humans

Toxicity, mutagenicity, and behavioral effects of {beta}-CIT, a ligand for dopamine transporter exploration by SPECT

Energy Technology Data Exchange (ETDEWEB)

Emond, P.; Farde, L.; Chalon, S.; Belzung, C.; Mauclaire, V.; Chiron, J. P.; Halldin, C.; Besnard, J.C.; Guilloteau, D

1998-05-01

The cocaine analog {beta}-CIT is one of the most used compounds for SPET examination of the dopamine transporter in drug abuse and Parkinson's disease. However, the toxicity of this agent has not yet been studied. We report here acute toxicity, mutagenicity, and effect on locomotor activity of {beta}-CIT. Acute toxicity experiments were performed in mice and rats. The LD50 values were about 20 mg and 5 mg for mice and rats, respectively. There was no sex difference. The mutagenicity was evaluated using the Ames' test. No mutagenic effect was observed for {beta}-CIT. Effects on locomotor activity were measured in mice using the open-field test. {beta}-CIT increased locomotion (+65%) when injected at a dose of 0.312 mg/kg; the maximal increase (+205%) was observed at a dose of 1.25 mg/kg; at higher doses, the effect was decreased slightly. These pharmacological findings are in agreement with an inhibitory effect of {beta}-CIT at the dopamine transporter. We conclude that with no mutagenic effects and LD50 more than 6 orders of magnitude higher than the routinely used doses in PET or SPET, it can be assumed that {beta}-CIT can be safely used as a radioligand in humans.

Mutagenicity and antimutagenicity of Baccharis dracunculifolia extract in chromosomal aberration assays in Chinese hamster ovary cells.

Science.gov (United States)

Munari, Carla Carolina; Resende, Flávia Aparecida; Alves, Jacqueline Morais; de Sousa, João Paulo; Bastos, Jairo Kenupp; Tavares, Denise Crispim

2008-09-01

Baccharis dracunculifolia De Candole (Asteraceae), a native plant from the Brazilian "cerrado", is widely used in folk medicine as an anti-inflammatory agent and for the treatment of gastrointestinal diseases. B. dracunculifolia has been described as the most important plant source of propolis in southeastern Brazil, which is called green propolis due to its color. The aim of the present study was to evaluate the mutagenic and antimutagenic effects of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE) on Chinese hamster ovary cells. On one hand, the results showed a significant increase in the frequencies of chromosome aberrations at the highest Bd-EAE concentration tested (100 microg/mL). On the other hand, the lowest Bd-EAE concentration tested (12.5 micro/mL) significantly reduced the chromosome damage induced by the chemotherapeutic agent doxorubicin. The present results indicate that Bd-EAE has the characteristics of a so-called Janus compound, that is, Bd-EAE is mutagenic at higher concentrations, whereas it displays a chemopreventive effect on doxorubicin-induced mutagenicity at lower concentrations. The constituents of B. dracunculifolia responsible for its mutagenic and antimutagenic effects are probably flavonoids and phenylpropanoids, since these compounds can act either as pro-oxidants or as free radical scavengers depending on their concentration.

Radiation and chemical mutagen induced somaclonal variations through in vitro organogenesis of cotton (Gossypium hirsutum L.).

Science.gov (United States)

Muthusamy, Annamalai; Jayabalan, Narayanasamy

2014-12-01

The purpose of the investigation was to induce somaclonal variations by gamma rays (GR), ethylmethane sulphonate (EMS) and sodium azide (SA) during in vitro organogenesis of cotton. The shoot tip explants were irradiated with 5-50 Gray (Gy) GR (Cobalt 60), 0.5-5.0 mM EMS and SA separately, and inoculated on Murashige and Skoog (MS) medium fortified with plant growth regulator (PGR) for organogenesis. The plantlets with well-developed root systems were acclimatized and transferred into the experimental field to screen the somaclonal variations during growth and development. The number of somaclonal variations was observed in growth of irradiated/treated shoot tips, multiplication, plantlet regeneration and growth in vitro and ex vitro. The lower doses/concentrations of mutagenic treatments showed significant enhancement in selected agronomical characters and they showed decreased trends with increasing doses/concentrations of mutagenic agents. The results of the present study revealed the influence of lower doses/concentrations of mutagenic treatments on in vitro and ex vitro growth of cotton plantlets and their significant improvement in agronomical characters which needs further imperative stability analysis. The present observations showed the platform to use lower doses/concentrations of mutagenic agents to induce variability for enhanced agronomical characters, resistant and tolerant cotton varieties.

Development and Application of a Human PBPK Model for Bromodichloromethane (BDCM) to Investigate Impacts of Multi-Route Exposure

Science.gov (United States)

Due to its presence in water as a volatile disinfection byproduct, BDCM, which is mutagenic and a rodent carcinogen, poses a risk for exposure via multiple routes. We developed a refined human PBPK model for BDCM (including new chemical-specific human parameters) to evaluate the...

Using Saccharomyces cerevisiae to test the mutagenicity of household compounds: an open ended hypothesis-driven teaching lab.

Science.gov (United States)

Marshall, Pamela A

2007-01-01

In our Fundamentals of Genetics lab, students perform a wide variety of labs to reinforce and extend the topics covered in lecture. I developed an active-learning lab to augment the lecture topic of mutagenesis. In this lab exercise, students determine if a compound they bring from home is a mutagen. Students are required to read extensive background material, perform research to find a potential mutagen to test, develop a hypothesis, and bring to the lab their own suspected mutagen. This lab uses a specially developed strain of Saccharomyces cerevisiae, D7, to determine if a compound is a mutagen. Mutagenesis of the D7 genome can lead to a scorable alteration in the phenotypes of this strain. Students outline and carry out a protocol for treatment of the yeast tester strain, utilizing the concept of dose/response and positive and negative controls. Students report on their results using a PowerPoint presentation to simulate giving a scientific presentation. The students' self-assessment of their knowledge indicated that, in all cases, the students felt that they knew more about the assay, mutagenesis, and the relationship between genotype and phenotype (P exercise.

Charged-particle mutagenesis 2. Mutagenic effects of high energy charged particles in normal human fibroblasts

Science.gov (United States)

Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

1994-01-01

The biological effects of high Linear Energy Transfer (LET) charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 sq micrometer and 0.09 to 5.56 x 10(exp -3) sq micrometer respectively. The maximum values were obtained by Fe-56 with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(exp -5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

The ability of two cooked food mutagens to induce aberrant crypt foci in mice

DEFF Research Database (Denmark)

Kristiansen, E.; Meyer, Otto A.; Thorup, I.

1997-01-01

induced a higher percentage of medium or large sized aberrant crypt foci than PhIP or IQ, The interpretation of the aberrant crypt foci as precursor lesions for colon cancer in the PhIP and IQ mice is difficult because PhIP and IQ have not been reported to be colonic carcinogens, If cooked food mutagens......The aberrant crypt foci assay has been used extensively to study different compounds for chemopreventive action, but almost all investigations have used initiators not normally found in the diet, In the present study two food-borne initiators, 2-amino-3-methyl-imidazo [4,5-f]quinoline (IQ) and 2......-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) were used, To simulate the human exposure further, we chose a feeding regimen with continuous low IQ- and PhIP-doses, Throughout the study female mice were given diets with or without 0.03% IQ or 0.03% PhIP, Two additional groups were given...

Mutagenic DNA repair in Escherichia coli: Pt. 17

International Nuclear Information System (INIS)

Sharif, F.; Bridges, B.A.

1990-01-01

In contrast to the dnaE485 mutation, which is nearly 'dead-stop', dnaE1026 allows DNA synthesis for some time at restrictive temperatures. When bacteria carrying the dnaE486 or dnaE1026 temperature-sensitive mutations were incubated at restrictive temperature after exposure to UV light they showed little or no fixation of mutations as determined by loss of photoreversibility and the mutation frequency fell progressively. These results confirm a role for DnaE protein in UV mutagenesis. A derivative of dnaE1026 carrying the umuC122 allele which blocks normal UV mutagenesis showed induction of mutations when photoreversing light was given to UV-irradiated bacteria after a period of incubation at either permissive or restrictive temperature. The defective DnaE1026 protein is therefore able to carry out the misincorporations postulated to be the first step in the mutagenic process. Its inability to give rise to mutations in umu + bacteria may therefore be attributed to its inability to participate in a later step. In contrast, UV-irradiated dnaE486 umuC122 bacteria did not show mutagenesis when incubated at restrictive temperature before photoreversal, suggesting that the altered DnaE486 protein was not able to carry out the postulate misincorporation step at 43 0 C. DNA polymerase III α-subunit therefore appears to be required for both the misincorporation and bypass steps in the two-step model for UV mutagenesis. (Author)

28. Annual Meeting of the European Environmental Mutagen Society

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

The 28{sup th} Annual Meeting of the European Environmental Mutagen Society took place in Salzburg from September 7{sup th} till September 11{sup th}, 1998. A lot of presentations also dealt with many radiation effects on cells, chromosomal aberrations and genetic effects caused by radioactive irradiation. In vivo and in vitro experiments concerning radiation injuries and carcinomas are analyzed. (Cecil)

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

International Nuclear Information System (INIS)

Sideropoulos, A.S.; Specht, S.M.; Jones, M.T.

1980-01-01

A simple screening methodology for the determination of mutagenictity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr + and hcr - are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm 2 , chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed mutational synergism. We have attempted to apply the procedure for securing data for mutational synergism between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 μg/ml), quinine hydrobromide (50 μg/ml), primaquine diphosphate (50 μg/ml), chloroquine (50μg/ml) and quinacrine dihydrochloride (25 μg/ml). All drugs tested give synergistic effets with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed. (orig.)

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

Energy Technology Data Exchange (ETDEWEB)

Sideropoulos, A S; Specht, S M; Jones, M T [Duquesne Univ., Pittsburgh, PA (USA). Dept. of Biological Sciences

1980-04-01

A simple screening methodology for the determination of mutagenictity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr/sup +/ and hcr/sup -/ are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm/sup 2/, chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed mutational synergism. We have attempted to apply the procedure for securing data for mutational synergism between ultraviolet (uv) radiation and a number of antimalarial drugs including quinine hydrochloride (50 ..mu..g/ml), quinine hydrobromide (50 ..mu..g/ml), primaquine diphosphate (50 ..mu..g/ml), chloroquine (50..mu..g/ml) and quinacrine dihydrochloride (25 ..mu..g/ml). All drugs tested give synergistic effects with uv light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of uv than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed.

Bacterial and human cell mutagenicity study of some C[sub 18]H[sub 10] cyclopenta-fused polycyclic aromatic hydrocarbons associated with fossil fuels combustion

Energy Technology Data Exchange (ETDEWEB)

Lafleur, A.L.; Longwell, J.P.; Marr, J.A.; Monchamp, P.A.; Thilly, W.G. (Massachusetts Institute of Technology, Cambridge (United States)); Mulder, P.P.Y.; Boere, B.B.; Cornelisse, J.; Lugtenburg, J. (Univ. of Leiden (Netherlands))

1993-06-01

A number of isomeric C[sub 18]H[sub 10] polycyclic aromatic hydrocarbons (PAHs), thought to be primarily cyclopenta-fused PAHs, are produced during the combustion and pyrolysis of fossil fuels. To determine the importance of their contributions to the total mutagenic activity of combustion and pyrolysis samples in which they are found, we characterized reference quantities of four C[sub 18]H[sub 10] CP-PAHs: benzol [ghi] fluoranthene (BF), cyclopenta [cd] pyrene (CPP), cyclopent [hi] acephenanthrylene (CPAP), and cyclopent [hi] acaenthrylene (CPAA). Synthesis of CPAA and CPAP is described. The availability of reference samples of these isomers also proved to be an essential aid in the identification of the C[sub 18]H[sub 10] species often found in combustion and pyrolysis samples. Chemical analysis of selected combustion and pyrolysis samples showed that CPP was generally the most abundant C[sub 18]H[sub 10] isomer, followed by CPAP and BF. CPAA was detected only in pyrolysis products from pure PAHs. We tested the four C[sub 18]H[sub 10] PAHs for mutagenicity in a forward mutation assay using S. typhimurium. CPP, BF, and CPAA were roughly twice as mutagenic as benzo[a]pyrene (BaP), whereas CPAP was only slightly active. These PAHs were also tested for mutagenic activity in human cells. In this assay, CPP and CPAA were strongly mutagenic but less active than BaP, whereas CPAP and BF were inactive at the dose levels tested. Also, the bacterial and human cell mutagenicity of CPAA and CPAP were compared with the mutagenicity of their monocyclopenta-fused analogs, aceanthrylene and acephenanthrylene. Although the mutagenicities of CPAP and acephenanthrylene are similar, the mutagenic activity of CPAA is an order of magnitude greater than that of aceanthrylene.

Mutagenicity in salmonella of nitro-organic compounds in extracts of fly ash of a fluidized-bed combustor

International Nuclear Information System (INIS)

Remsen, J.F.; Harris, W.R.

1983-01-01

The mutagenicity of a crude benzene/methanol extract of fly ash from an atmospheric fluidized-bed combustor was tested in Salmonella. Six strains were used including three which were mutants in a nitroreductase gene locus. The numbers of revertants from his- to his+ as a function of the amount of fly ash extracted were determined. The results showed that the major mutagens in the crude extract were nitro compounds from the fact that reversion rates in the nitro-reductase-deficient strains were significantly lower than in the parent strains from which they were derived. The responses of three parental strains, TA1538, TA98, and TA100, were quite similar, thus no conclusions could be made about frameshift versus base-substitution mutagens. No identification of specific nitro-organic compounds has been made

Intercellular distribution of mutations induced in oopcytes of Drosophila melanogaster by chemical and physical mutagens

International Nuclear Information System (INIS)

Traut, H.

1979-01-01

When females of Drosophila melanogaster are treated with chemical or physical mutagens, not only in one but also in both of the two homologous X chromosomes of a given oocyte, a recessive sex-linked lethal mutation may be induced. A method is described that discriminates between such single and double mutations. A theory is developed to show how a comparison betweeen the expected and the observer frequency of double mutations yields an indication of the intercellular distribution (random or nonrandom) of recessive lethal mutations induced by mutagenic agents in oocytes and, consequently, of the distribution (homogenous or nonhomogeneous) of those agents. Three agents were tested: FUdR (12.5, 50.0 and 81.0 μg/ml), mitomycin C (130.0 μg/ml) and x rays (2000 R, 150 kV). After FUdR feeding, no increase in the mutation frequency usually observed in D. melanogaster without mutagenic treatment was obtained (u = 0.13%, namely three single mutations among 2332 chromosomes tested). After mitomycin C feeding 104 single and three double mutations were obtained. All of the 50 mutations observed after x irradiation were single mutations. The results obtained in the mitomycin C and radiation experiments favor the assumption of a random intercellular distribution of recessive lethal mutations induced by these two agents in oocytes of D. melanogaster. Reasons are discussed why for other types of mutagenic agents nonrandom distributions may be observed with our technique

Peptide bond-forming reagents HOAt and HATU are not mutagenic in the bacterial reverse mutation test.

Science.gov (United States)

Nicolette, John; Neft, Robin E; Vanosdol, Jessica; Murray, Joel

2016-04-01

The peptide bond-forming reagents 1-hydroxy-7-azabenzotriazole (HOAt, CAS 39968-33-7) and O-(7-Azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, CAS 148893-10-1) either have structural alerts, unclassified features or are considered out of domain when evaluated for potential mutagenicity with in silico programs DEREK and CaseUltra. Since they are commonly used reagents in pharmaceutical drug syntheses, they may become drug substance or drug product impurities and would need to be either controlled to appropriately safe levels or tested for mutagenicity. Both reagents were tested in the bacterial reverse mutation (Ames) test at Covance, under GLP conditions, following the OECD test guideline and ICH S2(R1) recommendations and found to be negative. Our data show that HOAt and HATU-common pharmaceutical synthesis reagents-are not mutagenic, and can be treated as ordinary drug impurities. © 2016 Wiley Periodicals, Inc.

Assessing chemical mutagens: the risk to humans

International Nuclear Information System (INIS)

Brewen, J.G.

1978-01-01

Some topics discussed are as follows: chromosomal aberrations induced by x radiation, tritiated thymidine, maleic hydrazide, and nitrogen mustard; removal of pyrimidine dimers by photoreactivation in amphibian cells following uv radiation; effects of 4-nitroquinoline-oxide on leukocytes from XP and normal patients; DNA as a target for alkylating agents; sensitivity of spermatogonia to chemical mutagens; chromosomal aberrations induced by 8-ethoxycaffeine, methoxycaffeine, cytosine arabinoside, streptonigrin, bleomycin, and phleomycin; effects of MMS and triethylenemelamine on germ cells; and use of chromosomal aberrations for improving risk estimates for ionizing radiation

In vivo and in vitro evaluation of the mutagenic potential of carbamazepine: does melatonin have anti-mutagenic activity?

Science.gov (United States)

Awara, W M; El-Gohary, M; El-Nabi, S H; Fadel, W A

1998-01-16

The mutagenic potential of carbamazepine (CBZ) therapy has been evaluated both in vivo and in vitro. Analysis of chromosome aberrations (CA), sister chromatid exchanges (SCEs), mitotic and proliferation indices (PRI) were performed. The in vivo study was carried out on 30 patients with idiopathic epilepsy end undergoing treatment with CBZ for different periods starting from 6 months up to 15 years. Plasma CBZ levels were also determined for each patient. The results showed that the total CA and SCEs were significantly increased in CBZ-treated patients. There was no significant correlation between CA and either duration of treatment or the plasma CBZ levels for each patient. The mitotic and proliferation indices were found to be slightly but non-significantly decreased compared to control values. On the other hand, in vitro analysis showed a significant dose-dependent increase in CA and SCEs in human lymphocyte cultures treated with CBZ (4-12 microg/ml). The mitotic and proliferation indices were also found to be decreased but only significantly in case of high doses of CBZ (12 microg/ml). Pretreatment of human lymphocytes with melatonin (0.5 mM) exhibited a significant decrease in the frequencies of CBZ-induced CA and SCEs as compared with non-treated cultures. The depressed mitotic and proliferation indices were also found to be improved in cultures pretreated with melatonin. In conclusion, these observations suggest that CBZ monotherapy may lead to chromosome damaging effects (genotoxic) and the use of melatonin as anti-mutagenic agent for human protection against CBZ-induced chromosome damage should be considered.

Organic mutagens and drinking water in The Netherlands : a study on mutagenicity of organic constituents in drinking water in The Netherlands and their possible carcinogenic effects

NARCIS (Netherlands)

Kool, H.J.

1983-01-01

Several mutagenic and carcinogenic organic compounds have been detected in Dutch surface waters and in drinking water prepared from these surface waters. Although the levels of these compounds in drinking- and surface water are relatively low, in general below μg per litre, it appeared that organic

Biomedical and biophysical research and calibration projects: radiobiology. Chromosomal aberrations in human lymphocytes - response to mixed neutron/photon exposures

International Nuclear Information System (INIS)

Slabbert, J.P.; Hough, J.H.; Jansen, S.

1991-01-01

Whether synergistic interaction damage is realized when lymphocytes are exposed to mixed high/low LET radiation fields, and if so, how well these effects can be predicted, was investigated. Whole-blood samples were exposed, at 37 degrees C, to neutrons, 60 Co gamma-rays and a mixture of 25% neutrons and 75% photons. The mixture was delivered both sequentially and simultaneously. A significant difference between the sequential and simultaneous irradiations was evident. Both mixed-field exposures yield aberration frequencies in excess of the sum predicted for individual irradiations. 5 refs., 2 figs., 1 tab

Preclinical safety evaluation of intravenously administered mixed micelles.

Science.gov (United States)

Teelmann, K; Schläppi, B; Schüpbach, M; Kistler, A

1984-01-01

Mixed micelles, with their main constituents lecithin and glycocholic acid, form a new principle for the parenteral administration of compounds which are poorly water-soluble. Their composition of mainly physiological substances as well as their comparatively good stability substantiate their attractivity in comparison to existing solvents. A decomposition due to physical influences such as heat or storage for several years will almost exclusively affect the lecithin component in the form of hydrolysis into free fatty acids and lysolecithin. Their toxicity was examined experimentally in various studies using both undecomposed and artificially decomposed mixed micelles. In these studies the mixed micelles were locally and systemically well tolerated and proved to be neither embryotoxic, teratogenic nor mutagenic. Only when comparatively high doses of the undecomposed mixed micelles were administered, corresponding to approximately 30 to 50 times the anticipated clinical injection volume (of e.g. diazepam mixed micelles), did some vomitus (dogs), slight liver enzyme elevation (rats and dogs), and slightly increased liver weights (dogs) occur. After repeated injections of the artificially decomposed formulation (approximately 25% of lecithin hydrolyzed to free fatty acids and lysolecithin) effects such as intravascular haemolysis, liver enzyme elevations and intrahepatic cholestasis (dogs only) were observed but only when doses exceeding a threshold of approximately 40 to 60 mg lysolecithin/kg body weight were administered. All alterations were reversible after cessation of treatment.

Effects of chemical smokes on flora and fauna under field and laboratory exposures.

Science.gov (United States)

Schaeffer, D J; Novak, E W; Lower, W R; Yanders, A; Kapila, S; Wang, R

1987-06-01

Various types of obscurant smokes are used routinely in training by the U.S. Army. Because continued routine use of the smokes could be detrimental to the native flora and fauna at training sites, a preliminary biological and chemical field study of fogoil, hexachloroethane, and tank diesel smokes was conducted. Smoke plumes were sampled and chemically analyzed at distances of 15-150 m from the smoke source where Tradescantia clones 4430 and 03 and the native plant Ambrosia dumosa and the native rodent Dipodomys merriami were exposed for 30 min. In addition, Tradescantia clone 4430 was exposed to tank diesel in the laboratory at concentration levels equivalent to exposure at 15 and 50 m. Tradescantia clones were examined for mutagenic effects indicated by micronuclei induction in developing pollen and pink somatic mutations in stamen hairs. Photosynthetic perturbations were measured in Tradescantia and A. dumosa using variable fluorescence induction. Animals were examined for sister chromatid exchanges and chromosome aberrations. It was found that all of the smokes tested exerted varying degrees of physiological and mutagenic effects in one or more assay system at one or more exposure distance. The studies reported here indicate that exposed ecological systems, or at least components of these systems, are at a higher risk than are unexposed components (e.g., organisms) for several types of damage attributed to obscurant smoke exposure.

[Genetic control of the sensitivity of Aspergillus nidulans to mutagenic factors. VII. Inheritance of cross-sensitivity to different mutagenic factors by uvs-mutants].

Science.gov (United States)

Evseeva, G V; Kameneva, S V

1977-01-01

To study the inheritance of the sensitivity to UV, X-rays, methylmethanesulphonate (MMS), nitrosoguanidine (NG) and nitrous acid (NA) in five uvs mutants of Aspergillus nidulans, having multiple sensitivity to these factors, the sensitivity of recombinants obtained from crossing uvs mutants with uvs+ strain, resistant to all the factors analysed, and uvs leads to uvs+ revertants is investigated. Four uvs mutants (15, 17, 19 and 26) are found to have a nomogenic control of sensitivity to different mutagens. In one mutant (uvs11) the sensitivity to five factors is controlled by two non-linked mutations, one of them determining the sensitivity to UV, NG, NA, and the other--to X-rays and MMC. Phenotypic manifestations of uvs mutations is modified by cell genotype, both chromosomal and cytoplasmic factors being responsible for the modification. Phenotypic modification of uvs mutation results in the change to some (but not to all) mutagenic factors. It suggests, that not the product of uvs gene, but some other components of the reparation complex are modified. Otherwise, reparation of different DNA damages can be carried out by a single enzyme acting in different reparation complexes.

Operator dermal exposure and protection provided by personal protective equipment and working coveralls during mixing/loading, application and sprayer cleaning in vineyards.

Science.gov (United States)

Thouvenin, Isabelle; Bouneb, Françoise; Mercier, Thierry

2017-06-01

The efficiency of a working coverall combined with personal protective equipment to protect operators against dermal exposure to plant protection products under field conditions was studied. Operators wore a non-certified water-repellent finish polyester/cotton coverall plus a certified gown during the mixing/loading and the cleaning phases. Insecticide foliar application to a vineyard was selected as the exposure scenario. The overall dermal residue levels measured in this study were in the range of data recently collected in Europe. The water-repellent finish working coverall reduced body exposure by a factor of approximately 95%. Wearing a Category III Type 3 partial body gown during mixing/loading and cleaning of the application equipment led to a further protective effect of 98.7%. The combination of a water-repellent finish working coverall and partial body protection during specific tasks provided satisfactory levels of protection and can be considered as suitable protection for the conditions of use studied.

Toxicity, mutagenicity and transport in Saccharomyces cerevisiae of three popular DNA intercalating fluorescent dyes.

Science.gov (United States)

Sayas, Enric; García-López, Federico; Serrano, Ramón

2015-09-01

We have compared the toxicity, mutagenicity and transport in Saccharomyces cerevisiae of three DNA-intercalating fluorescent dyes widely used to stain DNA in gels. Safety data about ethidium bromide (EtBr) are contradictory, and two compounds of undisclosed structure (Redsafe and Gelred) have been proposed as safe alternatives. Our results indicate that all three compounds inhibit yeast growth, with Gelred being the most inhibitory and also the only one causing cell death. EtBr and Gelred, but not Redsafe, induce massive formation of petite (non-respiratory) mutants, but only EtBr induces massive loss of mitochondrial DNA. All three compounds increase reversion of a chromosomal point mutation (lys2-801(amber) ), with Gelred being the most mutagenic and Redsafe the least. These dyes are all cationic and are probably taken by cells through non-selective cation channels. We could measure the glucose-energized transport of EtBr and Gelred inside the cells, while uptake of Redsafe was below our detection limit. We conclude that although all three compounds are toxic and mutagenic in the yeast system, Redsafe is the safest for yeast, probably because of very limited uptake by these cells. Copyright © 2015 John Wiley & Sons, Ltd.

In vivo mutagenicity studies in rats mice and Chinese hamsters fed irradiated foodstuffs - chicken, fish, dates, pulses, mangoes and cocoa beans

International Nuclear Information System (INIS)

Renner, H.W.

1982-01-01

Three in vivo genetic toxicity tests were performed in rats, mice and Chinese hamsters to detect possible mutagenic effects of irradiated chicken, dried dates, fish, cocoa beans, pulses and mangoes. The tests employed were the micronucleus test and sister-chromatid exchange (SCE) test for irradiated and unirradiated samples of all foodstuffs listed, and the spermatogonia test, (including SCE technique) in mice for irradiated and unirradiated chicken, fish and dates only. In the case of cocoa beans, the mutagenicity tests were performed on an additional test group fed beans fumigated with ethylene oxide. The different mammalian species used for the various experiments are given below. None of the tests provided any evidence of mutagenicity induced by irradiation in any of the foodstuffs studied. Moreover, these tests are currently considered to be the most sensitive in vivo mutagenicity tests in mammals. (orig.)

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers.

Science.gov (United States)

Shaikh, Amrin; Barot, Darshana; Chandel, Divya

2018-04-01

Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation of gasoline fumes. The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Suppressive effects of coffee on the SOS responses induced by UV and chemical mutagens

International Nuclear Information System (INIS)

Obana, Hirotaka; Nakamura, Sei-ichi; Tanaka, Ryou-ichi

1986-01-01

SOS-inducing activity of UV or chemical mutagens was strongly suppressed by instant coffee in Salmonella typhimurium TA1535/pSK1002. As decaffeinated instant coffee showed a similarly strong suppressive effect, it would seem that caffeine, a known inhibitor of SOS responses, is not responsible for the effect observed. The suppression was also shown by freshly brewed coffee extracts. However, the suppression was absent in green coffee-bean extracts. These results suggest that coffee contains some substance(s) which, apart from caffeine, suppresses SOS-inducing activity of UV or chemical mutagens and that the suppressive substance(s) are produced by roasting coffee beans. (Auth.)

Fungal flora of Egyptian baladi bread with special reference to the mutagenic effects of their toxic metabolites.

Science.gov (United States)

Megalla, S E; Abdou, R F; Bagy, M M

1985-01-01

The fungal flora of wheat flour and baladi bread in upper Egypt were investigated. Most of the isolated fungal species belong to the genus Aspergillus. The presence of non heat resistant fungi of the both flat surfaces of baladi bread, came from contamination after baking and from improper handling at homes. Among the heat resistant fungi, A. fumigatus and A. niger, were recorded to inhabit the spongy crumb although the high temperature of baking process which reached approximately 100 degrees C in the center of the bread. The mutagenic effects of the fungal metabolites of the extract of mouldy Egypt were investigated. Most of the isolated fungal species all stages of mitotic division. The most interesting effect of these fungal metabolites were the induction of tripolar and quadripolar spindle. Multinucleate and polyploid cells were also observed under relatively high concentrations. It was noticed that at either higher concentrations or lower concentrations with long exposure, damaged cells were observed. The hazards involved through the consumption of individuals to such mouldy bread, is accumulation of possible deleterious effects from both long and short term exposure to these toxic metabolites.

Plants as warning signal for exposure to low dose radiation

International Nuclear Information System (INIS)

Rusli Ibrahim; Norhafiz Talib

2012-01-01

The stamen-hair system of Tradescantia for flower colour has proven to be one of the most suitable materials to study the frequency of mutations induced by low doses of various ionizing radiations and chemical mutagens. The system has also been used successfully for detecting mutagenic synergisms among chemical mutagens and ionizing radiations as well as for studying the variations of spontaneous mutation frequency. In this study of radiobiology, the main objective is to observe somatic mutation (occurrence of pink cells from blue cells) induced on stamen hairs of five Tradescantia sp. available in Malaysia after exposure to low doses of chronic gamma irradiation using Gamma Green House. Pink cells appeared only on Tradescantia Pallida Purpurea stamen hairs after 13 days of exposure to irradiation with different doses of gamma rays. The highest number of stamens with pink cells was recorded from flowers irradiated with the highest dose of 6.37 Gy with 0.07 Gy/ h of dose rate. The lowest number of stamens with pink cells was recorded with an average of 0.57, irradiated with the lowest dose of 0.91 Gy with 0.01 Gy/ h of dose rate. There were no pink cells observed on Tradescantia Spathaceae Discolor after exposure to different doses of gamma rays. Similar negative results were observed for the control experiments. The principal cells in this assay are the mitotic stamen hair cells developing in the young flower buds. After exposure to radiation, the heterozygous dominant blue character of the stamen hair cell is prevented, resulting in the appearance of the recessive pink color. Furthermore, no pink cell appears on all species of Tradescantia spathaceae after irradiated with different doses of gamma rays. The sensitivity of the Tradescantia has been used widely and has demonstrated the relation between radiation dose and frequency of mutation observed at low doses which can contribute to the effects of low doses and their consequences for human health. This system

Non-human primates avoid the detrimental effects of prenatal androgen exposure in mixed-sex litters: combined demographic, behavioral, and genetic analyses.

Science.gov (United States)

Bradley, Brenda J; Snowdon, Charles T; McGrew, William C; Lawler, Richard R; Guevara, Elaine E; McIntosh, Annick; O'Connor, Timothy

2016-12-01

Producing single versus multiple births has important life history trade-offs, including the potential benefits and risks of sharing a common in utero environment. Sex hormones can diffuse through amniotic fluid and fetal membranes, and females with male littermates risk exposure to high levels of fetal testosterone, which are shown to have masculinizing effects and negative fitness consequences in many mammals. Whereas most primates give birth to single offspring, several New World monkey and strepsirrhine species regularly give birth to small litters. We examined whether neonatal testosterone exposure might be detrimental to females in mixed-sex litters by compiling data from long-term breeding records for seven primate species (Saguinus oedipus; Varecia variegata, Varecia rubra, Microcebus murinis, Mirza coquereli, Cheirogaleus medius, Galago moholi). Litter sex ratios did not differ from the expected 1:2:1 (MM:MF:FF for twins) and 1:2:2:1 (MMM:MMF:MFF:FFF for triplets). Measures of reproductive success, including female survivorship, offspring-survivorship, and inter-birth interval, did not differ between females born in mixed-sex versus all-female litters, indicating that litter-producing non-human primates, unlike humans and rodents, show no signs of detrimental effects from androgen exposure in mixed sex litters. Although we found no evidence for CYP19A1 gene duplications-a hypothesized mechanism for coping with androgen exposure-aromatase protein evolution shows patterns of convergence among litter-producing taxa. That some primates have effectively found a way to circumvent a major cost of multiple births has implications for understanding variation in litter size and life history strategies across mammals. © 2016 Wiley Periodicals, Inc.

QSAR pre-screen of 70,983 substances for genotoxic carcinogenicity, mutagenicity and developmental toxicity in the EU FP7 project ChemScreen

DEFF Research Database (Denmark)

Wedebye, Eva Bay; Dybdahl, Marianne; Nikolov, Nikolai Georgiev

2014-01-01

be performed in REACH on known genotoxic carcinogens or germ cell mutagens with appropriate risk management measures implemented, a QSAR pre-screen for genotoxic carcinogenicity, germ cell mutagenicity and (limited) developmental toxicity was included in the project. Predictions for estrogenic and anti...... algorithms were applied to combine the predictions from the individual models to reach overall predictions for genotoxic carcinogenicity, germ cell mutagenicity and developmental toxicity. Furthermore, the full list of REACH pre-registered substances (143,835) was searched for substances containing certain...

Discerning the Chemical Composition and Mutagenic Effects of Soy Biodiesel PM

Science.gov (United States)

Discerning the Chemical Composition and Mutagenic Effects of Soy Biodiesel PM David G. Nashab, Esra Mutluc, William T. Prestond, Michael D. Haysb, Sarah H. Warrenc, Charly Kingc, William P. Linakb, M. lan Gilmourc, and David M. DeMarinic aOak Ridge Institute for Science and Ed...

Use of physical/chemical mutagens in plant breeding program in Vietnam

International Nuclear Information System (INIS)

Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich

2001-01-01

Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN 3 ). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

Use of physical/chemical mutagens in plant breeding program in Vietnam

Energy Technology Data Exchange (ETDEWEB)

Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich [Agricultural Genetics Institute, Hanoi (Viet Nam)

2001-03-01

Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN{sub 3}). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

Recent perspectives on the relations between faecal mutagenicity, genotoxicity and diet

Directory of Open Access Journals (Sweden)

Silvia eGratz

2011-03-01

Full Text Available DNA damage is an essential component of the genesis of colonic cancer. Gut microbial products and food components are thought to be principally responsible for the damage that initiates disease progression. Modified Ames tests and Comet assays have been developed for measuring mutagenicity and genotoxicity. Their relevance to oncogenesis remains to be confirmed, as does the relative importance of different mutagenic and genotoxic compounds present in faecal water and the bacteria involved in their metabolism. Dietary intervention studies provide clues to the likely risks of oncogenesis. High-protein diets lead to increases in N-nitroso compounds in faecal water and greater DNA damage as measured by the Comet assay, for example. Other dietary interventions, such as non-digestible carbohydrates and probiotics, may lead to lower faecal genotoxicity. In order to make recommendations to the general public, we must develop a better understanding of how genotoxic compounds are formed in the colon, how accurate the Ames and Comet assays are, and how diet affects genotoxicity.

Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

International Nuclear Information System (INIS)

Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

1976-01-01

It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

Mutagenic effects of irradiated glucose in Drosophila melanogaster

International Nuclear Information System (INIS)

Varma, M.B.; Rao, K.P.; Nandan, S.D.; Rao, M.S.

1982-01-01

The mutagenic effects of irradiated glucose were studied using the sex-linked recessive lethal test in Drosophila melanogaster. Oregon K males of D. melanogaster reared on a medium containing 20 or 40% glucose irradiated with a dose of 0.02, 0.10, 0.20, 2 or 5 Mrad #betta#-rays were scored for the induction of sex-linked recessive lethals. The results showed no significant increase in the frequency of X-lethals in Drosophila at any of the dose levels. (author)

Mutagenic effects of 3-carbethoxypsoralen and 8-methoxypsoralen plus 365-nm irradiation in mammalian cells

International Nuclear Information System (INIS)

Papadopoulo, D.; Sagliocco, F.; Averbeck, D.

1983-01-01

Cell survival, i.e. colony-forming ability, and the induction of 6-thioguanine-resistant (6-TGsup(r)) mutants were determined in Chinese hamster V79 cells by using two photoreactive furocoumarins of photochemotherapeutic interest: the bifunctional compound 8-methoxypsoralen (8-MOP) and the monofunctional compound 3-carbethoxypsoralen (3-CPs). To quantify the mutation induction in V79 cells mutants deficient in the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT) were selected with the purine analogue 6-thioguanine (6-TG). Both compounds exhibited lethal and mutagenic activities but the monofunctional compound 3-CPs was less lethal and mutagenic than the bifunctional compound 8-MOP. (Auth.)

Investigation of mutagenicity of extracts of hydrobionts from lake Drukshiai and water from its streamlets

International Nuclear Information System (INIS)

Lekevichius, R.; Dagyte, B.; Sabaliuniene, I.; Shumyliene, I.; Mishkelevichiute, E.

1995-01-01

Rain-water samples from Ignalina NPP buildings and industry sewerage water samples collected in 1993-1994 induced statistically significant increase in levels of frameshift and and base-substitution mutations in Salmonella typhimurium Ames tester strains. It was found that mutagens originated not by Ignalina NPP get into lake Drukshiai from its streamlets. Extracts from 4 species of molluscs did not induce frameshift and base-substitution mutations in Ames tester-strains. Among extracts of liver, muscles and gonads from 4 fish species tested, the highest mutagenicity levels were induced by extracts of gonads from the largest fish. (author). 4 refs., 4 tabs

Assessment of the mode of action for hexavalent chromium-induced lung cancer following inhalation exposures

International Nuclear Information System (INIS)

Proctor, Deborah M.; Suh, Mina; Campleman, Sharan L.; Thompson, Chad M.

2014-01-01

Highlights: • No published or well recognized MOA for Cr(VI)-induced lung tumors exists. • MOA analysis for Cr(VI)-induced lung cancer was conducted to inform risk assessment. • Cr(VI) epidemiologic, toxicokinetic, toxicological, mechanistic data were evaluated. • Weight of evidence does not support a mutagenic MOA for Cr(VI)-induced lung cancer. • Non-linear approaches should be considered for evaluating Cr(VI) lung cancer risk. - Abstract: Inhalation of hexavalent chromium [Cr(VI)] is associated with increased lung cancer risk among workers in several industries, most notably chromate production workers exposed to high concentrations of Cr(VI) (≥100 μg/m 3 ), for which clear exposure–response relationships and respiratory irritation and tissue damage have been reported. Data from this industry are used to assess lung cancer risk associated with environmental and current occupational exposures, occurring at concentrations that are significantly lower. There is considerable uncertainty in the low dose extrapolation of historical occupational epidemiology data to assess risk at current exposures because no published or well recognized mode of action (MOA) for Cr(VI)-induced lung tumors exists. We conducted a MOA analysis for Cr(VI)-induced lung cancer evaluating toxicokinetic and toxicological data in humans and rodents and mechanistic data to assess plausibility, dose–response, and temporal concordance for potential MOAs. Toxicokinetic data support that extracellular reduction of Cr(VI), which limits intracellular absorption of Cr(VI) and Cr(VI)-induced toxicity, can be overwhelmed at high exposure levels. In vivo genotoxicity and mutagenicity data are mostly negative and do not support a mutagenic MOA. Further, both chronic bioassays and the epidemiologic literature support that lung cancer occurs at exposures that cause tissue damage. Based on this MOA analysis, the overall weight of evidence supports a MOA involving deposition and accumulation

Quantitative changes in endogenous DNA damage correlate with conazole mutagenicity and tumorigenicity.

Science.gov (United States)

The mouse liver tumorigenic conazolefungicides triadimefon and propiconazole have previously been shown to be in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses, whereas the nontumorigenic conazole myclobutanil w...

Stimulation of germination of conidium Aspergillus niger, a citric acid producer, under the action of mutagenic factors

International Nuclear Information System (INIS)

Golubtsova, V.M.; Shcherbakova, E.Ya.; Smirnov, V.A.; Runkovskaya, L.Ya.

1976-01-01

The action of low doses of various mutagens, namely, 2% cyclophosphane solution (30 min), 1% thiophosphamide solution (30 min), 0.05% nitrosomethylurea solution (30 and 60 min), γ-rays (10 krads) and UV-rays (10000 erg/mm 2 ) stimulates germination of conidium Aspergillus niger, a citric acid producer. At the above-mentioned doses of mutagens, a minor quantity of morphological varieties are formed, and the variability value of acid production by Asp. niger is maintained at the spontaneous level

Mutagenicity of 1-Ethyl-2,4,5-triphenyl-1H-imidazole and Six Derivatives in Salmonella typhimurium

OpenAIRE

KORKMAZ, Ferhan; Korkmaz, Ferhan; MERCANGOZ, Ayse

2010-01-01

 Newly synthesized 1-Ethyl-2,4,5-triphenyl-1H-imidazole and its six derivatives were tested by Ames assay. In order to reveal the mutagenic activities of the compounds, two different mutant strains of Salmonella typhimurium (TA98 and TA100) were used in an Ames assay with/without S9 microsomal fraction from rat liver. It was found that the compounds have no mutagenic activities.          &nb...

Two nitro derivatives of azabenzo[a]pyrene N-oxide: Electronic properties and their relation to mutagenic activity

Energy Technology Data Exchange (ETDEWEB)

Ostojić, Bojana D., E-mail: bostojic@chem.bg.ac.rs; Đorđević, Dragana S.

2015-03-21

Highlights: • Molecular properties of nitro isomers of azabenzo[a]pyrene N-oxide are investigated. • Stability, ionization potential, electron affinity, and polarizability are determined. • High quality DFT methods are employed. • Nitroreduction, oxidation, and polarizability are not crucial for mutagenicity. • Dipole moment and electronic charge distribution are important for characterization. - Abstract: The equilibrium geometries, relative energies, IR and Raman spectra, vertical ionization potentials (IP), vertical electron affinities (EA), dipole moments (μ), electronic dipole polarizabilities (α), and molecular electrostatic potentials (MEP) of two species that show very high mutagenicity, 1-nitro-6-azabenzo[a]pyrene N-oxide (1-N-6-ABPO) and 3-nitro-6-azabenzo[a]pyrene N-oxide (3-N-6-ABPO), are investigated by means of Density Functional Theory (DFT) using B3LYP functional with different basis sets. The 3-N-6-ABPO isomer was estimated to be much more mutagenic in Salmonella typhimurium tester strain TA98 (396 000 revertants/nmol) than 1-N-6-ABPO (36 100 revertants/nmol) (Fukuhara et al., 1992). The results show that for both isomers the structural, energetic, and vibrational properties are similar. The orientation of the nitro group with respect to the plane of the aromatic system as well as the nitroreduction and oxidation reaction and polarizability seem not be important for the determination of different mutagenic behavior of these isomers. However, the dipole moment of 3-N-6-ABPO is about 3 times that of 1-N-6-ABPO. The larger dipole moment and the different electronic charge distribution of 3-N-6-ABPO compared to 1-N-6-ABPO imply stronger electrostatic and inductive molecular interactions so that the active site of the enzyme involved in the mutagenic activation can more effectively bind 3-N-6-ABPO compared to 1-N-6-ABPO.

Mutagenic and morphologic impacts of 1.8 GHz radiofrequency radiation on human peripheral blood lymphocytes (hPBLs) and possible protective role of pre-treatment with Ginkgo biloba (EGb 761)

Energy Technology Data Exchange (ETDEWEB)

Esmekaya, Meric Arda, E-mail: mericarda@yahoo.com [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey); Aytekin, Ebru [Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara (Turkey); Ozgur, Elcin; Gueler, Goeknur [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey); Ergun, Mehmet Ali [Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara (Turkey); Oemeroglu, Suna [Department of Histology and Embryology, Gazi University, Faculty of Medicine, Ankara (Turkey); Seyhan, Nesrin [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey)

2011-12-01

The mutagenic and morphologic effects of 1.8 GHz Global System for Mobile Communications (GSM) modulated RF (radiofrequency) radiation alone and in combination with Ginkgo biloba (EGb 761) pre-treatment in human peripheral blood lymphocytes (hPBLs) were investigated in this study using Sister Chromatid Exchange (SCE) and electron microscopy. Cell viability was assessed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) reduction assay. The lymphocyte cultures were exposed to GSM modulated RF radiation at 1.8 GHz for 6, 8, 24 and 48 h with and without EGb 761. We observed morphological changes in pulse-modulated RF radiated lymphocytes. Longer exposure periods led to destruction of organelle and nucleus structures. Chromatin change and the loss of mitochondrial crista occurred in cells exposed to RF for 8 h and 24 h and were more pronounced in cells exposed for 48 h. Cytoplasmic lysis and destruction of membrane integrity of cells and nuclei were also seen in 48 h RF exposed cells. There was a significant increase (p < 0.05) in SCE frequency in RF exposed lymphocytes compared to sham controls. EGb 761 pre-treatment significantly decreased SCE from RF radiation. RF radiation also inhibited cell viability in a time dependent manner. The inhibitory effects of RF radiation on the growth of lymphoctes were marked in longer exposure periods. EGb 761 pre-treatment significantly increased cell viability in RF + EGb 761 treated groups at 8 and 24 h when compared to RF exposed groups alone. The results of our study showed that RF radiation affects cell morphology, increases SCE and inhibits cell proliferation. However, EGb 761 has a protective role against RF induced mutagenity. We concluded that RF radiation induces chromosomal damage in hPBLs but this damage may be reduced by EGb 761 pre-treatment. - Highlights: Black-Right-Pointing-Pointer RF Radiation inhibits cell proliferation. Black-Right-Pointing-Pointer RF radiation induces chromosomal damage

Mutagenic and antimutagenic activities of Artemisia absinthium volatile oil by the bacterial reverse mutation assay in Salmonella typhimurium strains TA98 and TA100

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Mahboubeh Taherkhani

2014-09-01

Full Text Available Objective: To investigate the mutagenic and antimutagenic activities of Artemisia absinthium L. (A. absinthium essential oil by the bacterial reverse mutation assay in Salmonella typhimurium (S. typhimurium strains. Methods: Water-distilled essential oil of A. absinthium collected from Ardabil, NorthWestern Iran, was investigated for mutagenic and antimutagenic activities. In present study, the mutagenic and antimutagenic activities of A. absinthium oil were investigated by the bacterial revere mutation assay in S. typhimurium TA98 and TA100 strains with and without S9 (microsomal mutagenesis assay. Results: The comparative mutagenicity effect was seen in 1.5 mg/plate by the bacterial reverse mutation assay in S. typhimurium TA98 strains, without S9 and the excellent antimutagenicity effect was seen in 1.5 mg/plate against S. typhimurium TA100, without S9. Conclusions: The mutagenicity and antimutagenicity effects of the volatile oil of A. absinthium were seen without the presence of metabolic activation.

Comparison of BTX Profiles and Their Mutagenicity Assessment at Two Sites of Agra, India

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Vyoma Singla

2012-01-01

Full Text Available In the present study, the concentrations of three volatile organic compounds (VOCs, namely, acronym for benzene, toluene, and xylenes (BTX were assessed because of their role in the tropospheric chemistry. Two representative sites, a roadside and a petrol pump, were chosen for sample collection. VOCs were collected using SKC-activated charcoal tubes and SKC personal sampler and characterized by gas chromatograph using flame ionization detector. Among BTX, benzene had the highest concentration. At the roadside, mean concentration of benzene, toluene, o-,m-xylene, and p-xylene were 14.7 ± 2.4 μgm−3, 8.1 ± 1.2 μgm−3, 2.1 ± 0.8 μgm−3, and 5.1 ± 1.2 μgm−3, respectively. At the petrol pump, the mean concentrations of benzene, toluene, o-,m-xylene and p-xylene were 19.5 ± 3.7 μgm−3, 12.9 ± 1.1 μgm−3, 3.6 ± 0.5 μgm−3 and 11.1 ± 1.5 μgm−3, respectively, and were numerically higher by a fraction of 2. Monthly variation of BTX showed maximum concentration in winter. Inter-species ratios and inter-species correlation indicated traffic as the major source of BTX. Extracts of samples were positive in both Salmonella typhimurium tester strains TA98 and TA100 without metabolic activation suggesting the presence of direct mutagens in ambient air that can cause both frame-shift and base-pair mutation. The mutagenic response was greater for TA100 than TA98 suggesting greater activity for base-pair mutagenicity than frame-shift mutagenicity and was found to be statistically significant.

Cellular Mutagenicity and Heavy Metal Concentrations of Leachates Extracted from the Fly and Bottom Ash Derived from Municipal Solid Waste Incineration

Science.gov (United States)

Chen, Po-Wen; Liu, Zhen-Shu; Wun, Min-Jie; Kuo, Tai-Chen

2016-01-01

Two incinerators in Taiwan have recently attempted to reuse the fly and bottom ash that they produce, but the mutagenicity of these types of ash has not yet been assessed. Therefore, we evaluated the mutagenicity of the ash with the Ames mutagenicity assay using the TA98, TA100, and TA1535 bacterial strains. We obtained three leachates from three leachants of varying pH values using the toxicity characteristic leaching procedure test recommended by the Taiwan Environmental Protection Agency (Taiwan EPA). We then performed the Ames assay on the harvested leachates. To evaluate the possible relationship between the presence of heavy metals and mutagenicity, the concentrations of five heavy metals (Cd, Cr, Cu, Pb, and Zn) in the leachates were also determined. The concentrations of Cd and Cr in the most acidic leachate from the precipitator fly ash and the Cd concentration in the most acidic leachate from the boiler fly ash exceeded the recommended limits. Notably, none of the nine leachates extracted from the boiler, precipitator, or bottom ashes displayed mutagenic activity. This data partially affirms the safety of the fly and bottom ash produced by certain incinerators. Therefore, the biotoxicity of leachates from recycled ash should be routinely monitored before reusing the ash. PMID:27827867

Enhanced sensitivity to mutagens - EMS, MH, SM by pre-soaking - A taxometric study based on M{sub 1} parameters in finger millet

Energy Technology Data Exchange (ETDEWEB)

Singh, B; Sinha, S.K. [Plant Breeding and Genetics, OUAT, Bhubaneswar (India)], E-mail: sing_baburam@yahoo.co.in

2008-07-01

Pre-soaking seeds before treatment enhances sensitivity to many chemical mutagens; but little work has been done with maleic hydrazide (MH), a chromosome breaking agent and preferential inducer of micromutation and streptomycin (SM), a cytoplasmic mutagen. In the present investigation on pre-soaking (PS) effects in finger millet (Eleusine coracana, Gaertn), we included these two mutagens, besides one commonly used mutagen, EMS to determine a common effective PS range usingM{sub 1}seedling traits. Since differentM{sub 1}parameters, mutagens and their doses showed different peaks of response, we adopted a taxometric approach using all characters together. Combinations of chemicals, doses and sixM{sub 1}seedling attributes gave 48 characters for the numerical classification of PS periods (0, 8, 10, 12, 14, 16 and 18 h) as OTUs. Dendrogram from the similarity matrix using UPGMA clustering showed two clusters : (1) Cl. 1 of three OTUs (0, 8 and 10 h PS) and (2) Cl.2 of four OTUs(12-18h PS).We considered 12-18h as effective PS range and 0-10h as ineffective for all kinds of mutagens. The effective range would contain the major peak of sensitivity; the ineffective range might show a small peak. We confirmed these inferences with SM induced albinism as an indicator of plastid mutations. Higher doses shifted the peak within the effective range towards lower PS and low dose towards longer PS. Taxometrics could be usefully adopted in mutagenesis studies. (author)

Reaction mixtures formed by nitrite and selected sulfa-drugs showed mutagenicity in acidic medium

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Claudia Trossero

2009-01-01

Full Text Available Nitrite, which is present in preserved meat and can be produced in the oral cavity by reduction of nitrate taken from vegetables, could react in stomach with nitrosatable drugs, giving genotoxic-carcinogenic N-nitroso compounds (NOC. The mutagenicity of reaction mixtures formed by sodium nitrite and selected sulfa-drugs (sulfathiazole, HST; phtalylsulfathiazole, PhST; complex Co(II-sulfathiazole, Co(II-ST in acidic medium was evaluated using the Salmonella typhimurium reverse mutation assay (Ames test, with TA98 and TA 100 strains. The reactions were carried out at room temperature, with a mole ratio [nitrite]/[sulfa-drug] > 1. The three reaction mixtures showed mutagenic effects in the considered range.

Carcinogenic and mutagenic properties of chemicals in drinking water

Energy Technology Data Exchange (ETDEWEB)

Bull, R J

1985-12-01

Isolated cases of careless handling of industrial and domestic waste has lead to a wide variety of dangerous chemicals being inadvertently introduced into drinking water. However, chemicals with established carcinogenic and mutagenic properties that occur with a high frequency and in multiple locations are limited in number. To date, the chief offenders have been chemicals of relatively low carcinogenic potency. Some of the more common chemicals are formed as by-products of disinfection. The latter process is generally regarded as essential to the production of a ''microbiologically safe'' drinking water. Consequently, any reductions in what may be a relatively small carcinogenic risk must be balanced against a potential for a higher frequency of waterborne infectious disease. The results of recent toxicological investigations will be reviewed to place the potential carcinogenic and mutagenic hazards frequently associated with drinking water into perspective. First, evidence for the carcinogenicity of certain volatile organic compounds such as trichloroethylene, tetrachloroethylene and carbon tetrachloride is considered. Second, the carcinogenic activity that can be ascribed to various by-products of chlorination is reviewed in some detail. Finally, recent evidence that other chemicals derived from the treatment and distribution of drinking water is highlighted as an area requiring move systematic attention. 72 references.

Detection of mutagens in water-distribution systems after disinfection.

Science.gov (United States)

Guzzella, Licia; Di Caterino, Filomena; Monarca, Silvano; Zani, Claudia; Feretti, Donatella; Zerbini, Ilaria; Nardi, Giuseppe; Buschini, Annamaria; Poli, Paola; Rossi, Carlo

2006-09-19

This research examined the quality of water-before and after distribution-of four drinking-water production plants located in Northern Italy, two of which collected water from local aquifers and two from the River Po. A battery of genotoxicity assays for monitoring drinking-water was performed to assess the quality of the water produced by the treatment plants under study. Three different sampling stations were selected at each plant, one right at the outlet of the treatment plant and two along with the distribution pipelines. Raw river water was also sampled and analysed as a control. The water samples (500 l) were concentrated on silica C18 cartridges and the extracts were tested in in vitro mutagenicity assays (Salmonella/microsome assay with strains TA 98 and TA 100; SOS Chromotest with Escherichia coli strain PQ37); gene conversion, point mutation and mitochondrial DNA mutability assays with the diploid Saccharomyces cerevisiae strain D7 and a toxicity test using the bioluminescent bacterium Vibrio fischeri (Microtox). The Microtox test and the mitochondrial DNA mutability assay showed the greatest sensitivity towards toxic or mutagenic substances in the water extracts considered. The results show that this battery of short-term tests is applicable in the routine monitoring of drinking-water quality before and after distribution.

Comparative effects of ionizing radiation and two gaseous chemical mutagens on somatic mutation induction in one mutable and two non-mutable clones of Tradescantia

International Nuclear Information System (INIS)

Nauman, C.H.; Sparrow, A.H.; Schairer, L.A.

1976-01-01

The X-ray dose responses of mutable clone 0106 of Tradescantia (mutable for blue to pink), and its parent clone 02 have been determined for pink and colorless mutations in stamen hair cells, and are compared to the previously determined X-ray response for pink mutations of a third unrelated clone, clone 4430 (hybrid of T. subacaulis and T. hirsutiflora). X-ray response curves are compared to the response curves of the same three clones after exposure to the gaseous phase of the alkylating agent ethyl methanesulfate (EMS) and the fumigant and gasoline additive 1,2-dibromoethane (DBE). X-irradiation induces a pink mutation rate in mutable clone 0106 that is significantly higher than that of the nearly identical pink mutation rates in clones 02 and 4430. However, the colorless mutation rates of clones 02 and 0106 are not significantly different from one another. In clones 02 and 0106, pink mutations occur more frequently than colorless mutations at lower doses, but colorless dose-response curves saturate at higher doses than do those for pink mutations. Exposure-response curves for EMS and DBE have characteristics similar to those of X-ray response curves: exponential rise followed by an area of saturation. However, it was found that the relative sensitivities of the three clones to the gaseous mutagens and to ionizing radiation do not parallel one another. Where clones 02 and 4430 are equally sensitive to X-rays, at equal mutagen concentration clone 4430 is 6-7 times more sensitive to EMS and 7-9 times more sensitive to DBE than is clone 02. Mutable clone 0106 shows intermediate sensitivities to both EMS and DBE

Mutagenicity of diesel engine exhaust is eliminated in the gas phase by an oxidation catalyst but only slightly reduced in the particle phase.

Science.gov (United States)

Westphal, Götz A; Krahl, Jürgen; Munack, Axel; Ruschel, Yvonne; Schröder, Olaf; Hallier, Ernst; Brüning, Thomas; Bünger, Jürgen

2012-06-05

Concerns about adverse health effects of diesel engine emissions prompted strong efforts to minimize this hazard, including exhaust treatment by diesel oxidation catalysts (DOC). The effectiveness of such measures is usually assessed by the analysis of the legally regulated exhaust components. In recent years additional analytical and toxicological tests were included in the test panel with the aim to fill possible analytical gaps, for example, mutagenic potency of polycyclic aromatic hydrocarbons (PAH) and their nitrated derivatives (nPAH). This investigation focuses on the effect of a DOC on health hazards from combustion of four different fuels: rapeseed methyl ester (RME), common mineral diesel fuel (DF), SHELL V-Power Diesel (V-Power), and ARAL Ultimate Diesel containing 5% RME (B5ULT). We applied the European Stationary Cycle (ESC) to a 6.4 L turbo-charged heavy load engine fulfilling the EURO III standard. The engine was operated with and without DOC. Besides regulated emissions we measured particle size and number distributions, determined the soluble and solid fractions of the particles and characterized the bacterial mutagenicity in the gas phase and the particles of the exhaust. The effectiveness of the DOC differed strongly in regard to the different exhaust constituents: Total hydrocarbons were reduced up to 90% and carbon monoxide up to 98%, whereas nitrogen oxides (NO(X)) remained almost unaffected. Total particle mass (TPM) was reduced by 50% with DOC in common petrol diesel fuel and by 30% in the other fuels. This effect was mainly due to a reduction of the soluble organic particle fraction. The DOC caused an increase of the water-soluble fraction in the exhaust of RME, V-Power, and B5ULT, as well as a pronounced increase of nitrate in all exhausts. A high proportion of ultrafine particles (10-30 nm) in RME exhaust could be ascribed to vaporizable particles. Mutagenicity of the exhaust was low compared to previous investigations. The DOC reduced

Assessment of mutagenic damage by monofunctional alkylating agents and gamma radiation in haploid and diploid frogs, Xenopus laevis

International Nuclear Information System (INIS)

Hart, D.R.; Armstrong, J.B.

1984-01-01

Adult male South African clawed frogs, Xenopus laevis, were mutagenized by 3-day immersion in aqueous solutions of ethyl methanesulfonate (EMS), diethyl nitrosamine (DEN), or ethyl nitrosourea (ENU), or by acute exposure to gamma radiation. They were then spawned repeatedly at 2-week intervals with untreated females, and embryonic survival of the progeny was used to assess genetic damage. Recessive lethal effects were assessed from reduced survival of androgenetic haploid progeny. Neither recessive nor dominant lethal effects were obtained after exposure to 100 mg/liter EMS or 2 g/liter DEN. At 250 mg/liter EMS, peak dominant lethality occurred 3-5 weeks after treatment. Most embryos hatched, but many were abnormal and died shortly after hatching. Haploid survival was significantly reduced over a broader period, from 1 to 13 weeks after mutagenesis. Treatment with 75 mg/liter ENU produced effects similar to the 250-mg/liter EMS mutagenesis. At 400 mg/liter EMS, the frequency and severity of the effects on both diploid and haploid embryos were increased over the lower dose. Gamma irradiation at 1500 R produced effects similar to the 400-mg/liter mutagenesis, except that peak dominant lethality extended from 1 to 7 weeks

Characterization of mutagen-activated cellular oncogenes that confer anchorage independence to human fibroblasts and tumorigenicity to NIH 3T3 cells: Sequence analysis of an enzymatically amplified mutant HRAS allele

International Nuclear Information System (INIS)

Stevens, C.W.; Manoharan, T.H.; Fahl, W.E.

1988-01-01

Treatment of diploid human fibroblasts with an alkylating mutagen has been shown to induce stable, anchorage-independent cell populations at frequencies consistent with an activating mutation. After treatment of human foreskin fibroblasts with the mutagen benzo[α]pyrene (±)anti-7,8-dihydrodiol 9,10-epoxide and selection in soft agar, 17 anchorage-independent clones were isolated and expanded, and their cellular DNA was used to cotransfect NIH 3T3 cells along with pSV2neo. DNA from 11 of the 17 clones induced multiple NIH 3T3 cell tumors in recipient nude mice. Southern blot analyses showed the presence of human Alu repetitive sequences in all of the NIH 3T3 tumor cell DNAs. Intact, human HRAS sequences were observed in 2 of the 11 tumor groups, whereas no hybridization was detected when human KRAS or NRAS probes were used. Slow-migrating ras p21 proteins, consistent with codon 12 mutations, were observed in the same two NIH 3T3 tumor cell groups that contained the human HRAS bands. Genomic DNA from one of these two human anchorage-independent cell populations (clone 21A) was used to enzymatically amplify a portion of exon 1 of the HRAS gene. The results demonstrate that exposure of normal human cells to a common environmental mutagen yields HRAS GC → TA codon 12 transversions that have been commonly observed in human tumors

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

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Amrin Shaikh

2018-04-01

Full Text Available Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group and 70 healthy age-matched individuals with no known exposure (comparison group. Buccal micronucleus cytome assay (BMCyt was performed to check the genotoxicity caused due to inhalation of gasoline fumes. Results: The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Conclusion: Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Mutagenic effect of sewage waters of the Ignalina NPP on the cells of sea-trout

International Nuclear Information System (INIS)

Stasiunaite, P.

1996-01-01

Using a developing embryos of sea-trout as a test-object, the mutagenicity of water in the first biotope of Lake Drukshiai as well as in industrial and rain water sewer pipe was evaluated. Artesian water was used as a control one. The mutagenic potential of water in station 1 of Lake Drukshiai approximately made up 8.1% and statistically did not differ from the control (7.0%). The effect of water of station 7 upon the inherited embryonic cells was significantly greater, average frequency of chromosome aberration reaching 27.3%. The analysis of the obtained data showed that industrial - rain sewage water constantly penetrating into Lake Drukshiai may significantly worsen its ecological situation, i.e. to increase the accumulation of mutations in the communities and their amount in the succeeding generations. The genotoxicity of water of the 1 st biotope of Lake Drukshiai, which is the farthest point from the Ignalina NPP, may be used as a control when investigating the mutagenic impact of water of other biotopes in the lake, especially in the stations located at the shortest distance from the energetic objects. 8 refs., 1 tab

Cytotoxicity and mutagenicity of cola and grape flavored soft drinks in bone marrow cells of rodents

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Elisângela Düsman

2013-03-01

Full Text Available Due to the large consumption of soft drinks in Brazil and worldwide in recent years and considering that some of the components present in their composition pose potential risks to human health, the aim of this study was to evaluate the cytotoxic and mutagenic potential of specific cola and grape-flavored soft drink brands. Bone marrow cells of Wistar rats were initially treated by gavage with one single dose of Cola or Grape soft drink, which was next offered ad libitum (instead of water for 24 hours. A negative control treatment was performed by administering one single dose of water and a positive control administering cyclophosphamide intraperitoneally. Statistical analysis showed that the Cola and Grape soft drinks studied were not cytotoxic. However, the Cola soft drink proved mutagenic in this experiment treatment time. Therefore, this study serves as a warning about the consumption of Cola-flavored soft drink and for the need for further subchronic and chronic studies on soft drinks in order to evaluate the long term mutagenic and cytotoxic effects of these substances.

Molecular basis of the mutagenic and lethal effects of ultraviolet irradiation

International Nuclear Information System (INIS)

Grossman, L.

1982-01-01

Using bacteria as a model, the molecular basis of the mutagenic and lethal effects of uv radiation is being studied. Attention is focused on the mechanism of action of uv-1 specific endonucleases in the repair of damaged DNA. The isolation and identification of similar enzymes in human cells are being conducted concurrently

Mutagenic effects of tributyltin and inorganic lead (Pb II on the fish H. malabaricus as evaluated using the comet assay and the piscine micronucleus and chromosome aberration tests

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Ferraro Marcos Vinícius M.

2004-01-01

Full Text Available Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT and inorganic lead (PbII using samples of the fish Hoplias malabaricus (commonly called traíra using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 mg/g of body weight (bw of TBT, six to 21 mg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus which had been injected with solutions of TBT, PbII or with water (the control group. After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01, the micronucleus assay showing morphological alterations of the nucleus.

Test of mutagenicity of an irradiated standard diet for laboratory animals in the host-mediated assay with salmonella typhimurium TA 1530

International Nuclear Information System (INIS)

Muenzner, R.; Renner, H.W.

1976-01-01

Feed irradiated at a dose of 3 Mrad was tested for mutagenic activity in the host-mediated assay with the mouse as host and Salmonella typhimurium TA 1530 as indicator organism. In the in vivo and in the in vitro comparative test the irradiated feed showed no mutagenic effect. (orig.) [de

The mouse lymphoma thymidine kinase assay for the assessment and comparison of the mutagenic activity of cigarette mainstream smoke particulate phase.

Science.gov (United States)

Schramke, H; Meisgen, T J; Tewes, F J; Gomm, W; Roemer, E

2006-10-29

The mouse lymphoma thymidine kinase assay (MLA) has been optimized to quantitatively determine the in vitro mutagenicity of cigarette mainstream smoke particulate phase. To test whether the MLA is able to discriminate between different cigarette types, specially constructed cigarettes each containing a single tobacco type - Bright, Burley, or Oriental - were investigated. The mutagenic activity of the Burley cigarette was statistically significantly lower, up to approximately 40%, than that of the Bright and Oriental cigarettes. To determine the impact of two different sets of smoking conditions, American-blend cigarettes were smoked under US Federal Trade Commission/International Organisation for Standardisation conditions and under Massachusetts Department of Public Health (MDPH) conditions. Conventional cigarettes - eight from the US commercial market plus the Reference Cigarettes 1R4F and 2R4F - and an electrically heated cigarette smoking system (EHCSS) prototype were tested. There were no statistically significant differences between the two sets of smoking conditions on a per mg total particulate matter basis, although there was a consistent trend towards slightly lower mutagenic activity under MDPH conditions. The mutagenic activity of the EHCSS prototype was distinctly lower than that of the conventional cigarettes under both sets of smoking conditions. These results show that the MLA can be used to assess and compare the mutagenic activity of cigarette mainstream smoke particulate phase in the comprehensive toxicological assessment of cigarette smoke.

Effects of prenatal exposure to nanoparticles titanium dioxide and carbon black on female germline DNA stability

DEFF Research Database (Denmark)

Boisen, Anne Mette Zenner

Particulate air pollution has been associated with an increased risk of cardiovascular disease and cancer in humans. Air pollution may also adversely affect pregnancy outcome and the integrity of sperm cells DNA. Animal studies have shown that inhalation of air particulates can induce mutations...... in premeiotic sperm cells. The investigation of potential mutagenic risk is of outmost importance, as it may lead to cancer. Furthermore, heritable mutations may be passed on to descendents and thereby pose a permanent genetic risk to the population. The nanosized fraction of particulate air pollution has...... are needed. Expanded simple tandem repeat (ESTR) loci in mice are sensitive markers of mutagenic effects resulting from environmental exposures; Studies on adult mice have revealed that while particulate air pollution induced ESTR mutations in premeiotic sperm cells, the female germline was not affected...

Radiation-induced mutagenicity in repair deficient Chinese hamster ovary (CHO) mutants

International Nuclear Information System (INIS)

Tesmer, J.G.; Saunders, E.H.; Chen, D.J.

1987-01-01

To determine if there is a relationship between DNA double-strand break repair and mutagenicity the authors utilized two x-ray sensitive mutants of Chinese hamster ovary cells along with the parental line K1. The two mutant lines xrs-5 and xrs-6, which have different DSB repair capabilities, were used to determine cell killing and 6-thioguanine resistance (6TG/sup r/) mutation frequencies induced by either x-rays of α-particles, x-ray survival data indicated the two mutant lines have similar sensitivity and are 5-7 fold more sensitive than the parental line K1. The mutant lines are also sensitive to α-particles but to a lesser extent. The authors' 6TG mutation data indicated that the two mutant lines are hypermutable. When mutation frequencies were plotted against the log of survival, mutation frequency at a given survival level was greater in mutant cell population than in parental K1 cells. Their results support the notion that repair of DSB play an important role in the expression of radiation-induced cell killing and mutagenicity

Potential use of DNA adducts to detect mutagenic compounds in soil

International Nuclear Information System (INIS)

Hua Guoxiong; Lyons, Brett; Killham, Ken; Singleton, Ian

2009-01-01

In this study, three different soils with contrasting features, spiked with 300 mg benzo[a]pyrene (BaP)/kg dry soil, were incubated at 20 deg. C and 60% water holding capacity for 540 days. At different time points, BaP and DNA were extracted and quantified, and DNA adducts were quantified by 32 P-postlabelling. After 540 days incubation, 69.3, 81.6 and 83.2% of initial BaP added remained in Cruden Bay, Boyndie and Insch soils, respectively. Meanwhile, a significantly different amount of DNA-BaP adducts were found in the three soils exposed to BaP over time. The work demonstrates the concept that DNA adducts can be detected on DNA extracted from soil. Results suggest the technique is not able to directly reflect bioavailability of BaP transformation products. However, this new method provides a potential way to detect mutagenic compounds in contaminated soil and to assess the outcomes of soil remediation. - A novel DNA adduct assay may provide a potential technique to detect mutagenic compounds in contaminated soil

Alkaline azide mutagenicity in cowpea

Energy Technology Data Exchange (ETDEWEB)

Mahna, S K; Bhargava, Anubha; Mohan, Lalit [Cytogenetics and Mycology Laboratory, Department of Botany, Government College, Ajmer (India)

1990-07-01

Sodium azide is known as a potent mutagen in cereals and legumes. It is very effective in acidic medium in barley. Here an attempt is made to measure the effectiveness of sodium azide in alkaline medium (pH 7.4) on cowpea (Vigna unguiculata (L.) Walp., variety FS-68). Seeds pre-soaked in distilled water for 5 hours were treated with different concentrations (10{sup -6}, 10{sup -5}, 10{sup -4} and 10{sup -3}M) of sodium azide (NaN{sub 3}) for 4 hours at 28{+-} 2 deg. C. Bottles were intermittently shaken, then the seeds were thoroughly washed in running tap water and subsequently planted in pots. The treatment caused significant biological damage such as reduction in seed germination, length of root and shoot, number of nodules and pods per plant and morphological leaf variations. Morphological, as well as chlorophyll mutants, were detected in M{sub 2}.

Alkaline azide mutagenicity in cowpea

International Nuclear Information System (INIS)

Mahna, S.K.; Bhargava, Anubha; Mohan, Lalit

1990-01-01

Sodium azide is known as a potent mutagen in cereals and legumes. It is very effective in acidic medium in barley. Here an attempt is made to measure the effectiveness of sodium azide in alkaline medium (pH 7.4) on cowpea (Vigna unguiculata (L.) Walp., variety FS-68). Seeds pre-soaked in distilled water for 5 hours were treated with different concentrations (10 -6 , 10 -5 , 10 -4 and 10 -3 M) of sodium azide (NaN 3 ) for 4 hours at 28± 2 deg. C. Bottles were intermittently shaken, then the seeds were thoroughly washed in running tap water and subsequently planted in pots. The treatment caused significant biological damage such as reduction in seed germination, length of root and shoot, number of nodules and pods per plant and morphological leaf variations. Morphological, as well as chlorophyll mutants, were detected in M 2

CONCRETE MIX DESIGN FOR STRUCTURES SUBJECTED TO EXPOSURE CLASS XC1 DEPENDING ON CONCRETE COVER

Directory of Open Access Journals (Sweden)

O. Yu. Cherniakevich

2016-01-01

Full Text Available The reinforced steel corrosion which is the most important problem of reinforced concrete structures durability is generally stipulated for carbonization of concrete surrounding it. Concrete cover calculation at the design stage is predicated one because of the differences in manufacturing conditions and use of constructions. The applying of the probabilistic approaches to the carbonation process modeling allows to get predicated grade of the depth of carbonization of concrete and, thus, to settle minimum concrete cover thickness for a given projected service life of a construction. The procedures for concrete mix design for different strength classes of concrete are described in the article. Current recommendations on assignment of concrete strength class as well as concrete cover are presented. The European Standard EN 206:2013 defines the content requirements for the concrete structures operated in the exposure class XC1, including the minimum values of water-cement ratio, minimum cement content, and minimum strength class of concrete. Since the standard does not include any basis or explanations of the requirements, we made an effort to develop a scientific justification for the mentioned requirements. We developed the probabilistic models for the process of carbonation of concrete based on the concrete mix which was designed using the software VTK-Korroziya. The reinforced concrete structures with concrete cover 20–35 mm operated in the most unfavorable conditions within the exposure class XC1 were analyzed. The corresponding probabilistic calculations of the depth of carbonated concrete are described in the article. 

Computational Model Prediction and Biological Validation Using Simplified Mixed Field Exposures for the Development of a GCR Reference Field

Science.gov (United States)

Hada, M.; Rhone, J.; Beitman, A.; Saganti, P.; Plante, I.; Ponomarev, A.; Slaba, T.; Patel, Z.

2018-01-01

The yield of chromosomal aberrations has been shown to increase in the lymphocytes of astronauts after long-duration missions of several months in space. Chromosome exchanges, especially translocations, are positively correlated with many cancers and are therefore a potential biomarker of cancer risk associated with radiation exposure. Although extensive studies have been carried out on the induction of chromosomal aberrations by low- and high-LET radiation in human lymphocytes, fibroblasts, and epithelial cells exposed in vitro, there is a lack of data on chromosome aberrations induced by low dose-rate chronic exposure and mixed field beams such as those expected in space. Chromosome aberration studies at NSRL will provide the biological validation needed to extend the computational models over a broader range of experimental conditions (more complicated mixed fields leading up to the galactic cosmic rays (GCR) simulator), helping to reduce uncertainties in radiation quality effects and dose-rate dependence in cancer risk models. These models can then be used to answer some of the open questions regarding requirements for a full GCR reference field, including particle type and number, energy, dose rate, and delivery order. In this study, we designed a simplified mixed field beam with a combination of proton, helium, oxygen, and iron ions with shielding or proton, helium, oxygen, and titanium without shielding. Human fibroblasts cells were irradiated with these mixed field beam as well as each single beam with acute and chronic dose rate, and chromosome aberrations (CA) were measured with 3-color fluorescent in situ hybridization (FISH) chromosome painting methods. Frequency and type of CA induced with acute dose rate and chronic dose rates with single and mixed field beam will be discussed. A computational chromosome and radiation-induced DNA damage model, BDSTRACKS (Biological Damage by Stochastic Tracks), was updated to simulate various types of CA induced by

Non-random alkylation of DNA sequences induced in vivo by chemical mutagens

Energy Technology Data Exchange (ETDEWEB)

Durante, M.; Geri, C.; Bonatti, S.; Parenti, R. (Universita di Pisa (Italy))

1989-08-01

Previous studies of the interaction of alkylating agents on the eukaryotic genome support the idea that induction of DNA adducts is at specific genomic sites. Here we show molecular and cytological evidence that alkylation is rather specific. Mammalian cell cultures were exposed to different doses of mutagens and the DNA was analyzed by density gradient ultracentrifugation, hydroxylapatite fractionation, and by restriction enzyme analysis. Studies with the labelled mutagens N-ethyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine show that there is a non-random distribution of the adducts. The adducts are found more frequently in A-T, G-C rich satellite DNA and highly repetitive sequences. Analysis with restriction enzymes shows that both methyl and ethyl groups influence the restriction patterns of the enzymes HpaII and MspI that recognize specific endogenous DNA methylation. These data suggest, as a subsequent mechanism, a modification in the pattern of the normal endogenous methylation of 5-methylcytosine.

Comparative study of the mutagenic and genotoxic activity associated with inhalable particulate matter in Rio de Janeiro air

Energy Technology Data Exchange (ETDEWEB)

Miguel, A.G.; Daisey, J.M.; Sousa, J.A. (Federal Univ. of Rio de Janeiro (Brazil))

1990-01-01

We have determined the genotoxic and mutagenic activities associated with inhalable particulate matter (IPM) collected in Rio de Janeiro, Brazil, Camden, NJ, and Caldecott Tunnel, CA, and used these results to compare three different bioassays. Samples collected every 12 hr (Rio) or every 24 hr (Camden) were extracted sequentially with cyclohexane (CX), dichloromethane (DCM), and acetone (ACE), for a rough fractionation by polarity, and composites of the extracts were tested for mutagenicity using the Salmonella frame shift (TA98) and base substitution (TA100) tester strains, as well as for genotoxicity using the Rossman Microscreen bioassay based on the induction of lambda-prophage in a lysogenic Escherichia coli strain. All samples were tested without and with S9 metabolic activation. Maximum mutagenic and genotoxic activities were in the nonpolar (CX) and polar (ACE) fractions, respectively, indicating that these two assays detect different classes of compounds with different efficiencies. Oxidative aging of the Rio aerosol is indicated by a shift in activities in both tests from the less polar fractions in the day to the polar (ACE) fraction at night. The Rio TA98 mutagenic (18 rev/m3) and genotoxic (1.4 x 10(5) PFU/m3) activities were higher than those for Camden, an Eastern U.S. city, by factors of 1.4 and 2.8, respectively.

Predictive Models for Carcinogenicity and Mutagenicity: Frameworks,State-of-the-Art, and Perspectives

Science.gov (United States)

Mutagenicity and carcinogenicity are endpoints of major environmental and regulatory concern. These endpoints are also important targets for development of alternative methods for screening and prediction due to the large number of chemicals of potential concern and the tremendou...

The role of genotype in the mutagenic effect of ionizing radiations with different LET on E. coli cells

International Nuclear Information System (INIS)

Tokarova, B.; Amirtaev, K.G.; Krasavin, E.A.; Kozubek, S.

1988-01-01

The mutagenic effects of γ-irradiation and accelerated deuterium and helium ions on Escherichia coli cells with various repair genotype (wild type, pol A, lex A, and rec BC mutants) have been investigated. It has been shown that the types of dose dependences of the mutagenic effect and the relative genetic effectivenes for various linear energy transfers of ionizing radiation differ in the case of repair deficient mutants and are discussed in terms of current hypotheses. 12 refs.; 2 figs.; 2 tabs

Problems in extrapolating genotoxicity data from cellular systems in vitro

Energy Technology Data Exchange (ETDEWEB)

Mohn, G.R.; van Zeeland, A.A.

1986-01-01

The experiments involved quantitative comparative mutagenesis determinations using ethylating agents differing in DNA reactivity, mammalian metabolism, and mutagenic potency. The results can be summarized as follows: (1) Under standardized in vitro treatment conditions and at identical DNA dose levels, the frequencies of induced mutations observed in the present bacterial systems are not representative and usually lower than those induced in cultured mammalian cells. (2) Under the same in vitro treatment conditions, the relative mutagenic potency order is identical in bacteria and the mammalian cells, namely, N-ethyl-N'-nitrosoquinioline(ENNG) > ethylnitrosourea (ENU) > diethylsulfate (DES) > ethylmethanesulfonate (EMS); diethylnitrosamine (DEN) being not mutagenic in the two organisms without addition of mammalian (rodent) liver preparations containing Cyt-P450-dependent mixed function oxidases. (3) The extremely high mutagenic activity of ENNG in bacteria and mammalian cells in vitro is very probably due to its intracellular, glutathione-mediated activation to highly reactive chemical species. (4) Both in bacteria and the mammalian cells the frequencies of induced mutations are directly proportional to the levels of O6-ethylguanine formed in DNA after exposure to ENNG, ENU, DES, and EMS, in contrast to results obtained when other DNA adducts are used as dose parameters. (5) The addition of mouse liver S-9 preparations in the in vitro assays allows to determine which chemicals are likely to be substantially activated (DEN) or deactivated (ENNG) in vivo; however, the mutagenic potency order remained the same under these conditions. (6) When the indicator bacteria are exposed directly to the in vivo metabolism of living animals, the relative order of mutagenic potency on the basis of exposure levels becomes drastically different from that observed in vitro, using either E. coli or V79 mammalian cells.

No-observed effect levels are associated with up-regulation of MGMT following MMS exposure.

Science.gov (United States)

Doak, Shareen H; Brüsehafer, Katja; Dudley, Ed; Quick, Emma; Johnson, George; Newton, Russell P; Jenkins, Gareth J S

2008-12-15

The alkylating agents methyl methanesulphonate (MMS) and ethyl methanesulphonate (EMS) have non-linear dose-response curves, with a no-observed effect level (NOEL) and a lowest observed effect level (LOEL) for both gross chromosomal damage and mutagenicity. However, the biological mechanism responsible for the NOEL has yet to be identified. A strong candidate is DNA repair as it may be able to efficiently remove alkyl adducts at low doses resulting in a NOEL, but at higher doses fails to fully remove all lesions due to saturation of enzymatic activity resulting in a LOEL and subsequent linear increases in mutagenicity. We therefore assessed the transcriptional status of N-methylpurine-DNA glycoslase (MPG) and O(6)-methylguanine DNA methyltransferase (MGMT), which represent the first line of defence following exposure to alkylating agents through the respective enzymatic removal of N7-alkylG and O(6)-alkylG. The relative MPG and MGMT gene expression profiles were assessed by real-time RT-PCR following exposure to 0-2 microg/ml MMS for 1-24h. MPG expression remained fairly steady, but in contrast significant up-regulation of MGMT was observed when cells were treated with 0.5 and 1.0 microg/ml MMS for 4h (2.5- and 6.5-fold increases respectively). These doses lie within the NOEL for MMS mutagenicity (LOEL is 1.25 microg/ml), thus this boost in MGMT expression at low doses may be responsible for efficiently repairing O(6)methylG lesions and creating the non-linear response for mutations. However, as the LOEL for MMS clastogenicity is 0.85 microg/ml, O(6)-alkylG is unlikely to be responsible for the clastogenicity observed at these concentrations. Consequently, at low doses N7-methylG is possibly the predominant cause of MMS clastogenicity, while O(6)-methylG is more likely to be responsible for MMS mutagenicity, with MGMT up-regulation playing a key role in removal of O(6)-alkylG lesions before they are fixed as permanent point mutations, resulting in non-linear dose

Trichloroethylene Biotransformation and its Role in Mutagenicity, Carcinogenicity and Target Organ Toxicity

Science.gov (United States)

Lash, Lawrence H.; Chiu, Weihsueh A.; Guyton, Kathryn Z.; Rusyn, Ivan

2014-01-01

Metabolism is critical for the mutagenicity, carcinogenicity, and other adverse health effects of trichloroethylene (TCE). Despite the relatively small size and simple chemical structure of TCE, its metabolism is quite complex, yielding multiple intermediates and end-products. Experimental animal and human data indicate that TCE metabolism occurs through two major pathways: cytochrome P450 (CYP)-dependent oxidation and glutathione (GSH) conjugation catalyzed by GSH S-transferases (GSTs). Herein we review recent data characterizing TCE processing and flux through these pathways. We describe the catalytic enzymes, their regulation and tissue localization, as well as the evidence for transport and inter-organ processing of metabolites. We address the chemical reactivity of TCE metabolites, highlighting data on mutagenicity of these end-products. Identification in urine of key metabolites, particularly trichloroacetate (TCA), dichloroacetate (DCA), trichloroethanol and its glucuronide (TCOH and TCOG), and N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NAcDCVC), in exposed humans and other species (mostly rats and mice) demonstrates function of the two metabolic pathways in vivo. The CYP pathway primarily yields chemically stable end-products. However, the GST pathway conjugate S-(1,2-dichlorovinyl)glutathione (DCVG) is further processed to multiple highly reactive species that are known to be mutagenic, especially in kidney where in situ metabolism occurs. TCE metabolism is highly variable across sexes, species, tissues and individuals. Genetic polymorphisms in several of the key enzymes metabolizing TCE and its intermediates contribute to variability in metabolic profiles and rates. In all, the evidence characterizing the complex metabolism of TCE can inform predictions of adverse responses including mutagenesis, carcinogenesis, and acute and chronic organ-specific toxicity. PMID:25484616

Mutagen Sensitivity, Apoptosis, and Polymorphism in DNA Repair as Measures of Prostate Cancer Risk

National Research Council Canada - National Science Library

Goldman, Radoslav

2006-01-01

.... We also created a computerized database of the samples in Microsoft Access. We developed assays for mutagen sensitivity, comet assay, and apoptosis in white blood cells exposed to bleomycin and ionizing radiation to evaluate...

Mutagenicity of New Lead Compounds to Treat Sickle Cell Disease Symptoms in a Salmonella/Microsome Assay

Directory of Open Access Journals (Sweden)

Chung Man Chin

2010-02-01

Full Text Available A series of phthalimide derivatives planned as drugs candidates to treat the symptoms of sickle cell anemia were evaluated in a mutagenicity test using strains of Salmonella typhimurium TA100 and TA102, without and with addition of S9 mixture, with the aim to identify the best structural requirements for a drug candidate without genotoxic activity. The compounds (1,3-dioxo-1,3-dihydro-2H-isoindol-2-ylmethyl nitrate (1; (1,3-dioxo-1,3-dihydro-2H-isoindol-2-ylethyl nitrate (2; 3-(1,3-dioxo-1,3-dihydro-2H-iso-indol-2-ylbenzyl nitrate (3; 4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl-N-hydroxy-benzenesulfonamide (4; 4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-ylbenzyl nitrate (5 and 2-[4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-ylphenyl]ethyl nitrate (6 presented mutagenic potency ranging between 0-4,803 revertants/μmol. These results allowed us to propose that a methyl spacer linked to a nitrate ester subunit associated to meta aromatic substitution decreases mutagenicity.

Genome-wide screening for genes whose deletions confer sensitivity to mutagenic purine base analogs in yeast

Directory of Open Access Journals (Sweden)

Kozmin Stanislav G

2005-06-01

Full Text Available Abstract Background N-hydroxylated base analogs, such as 6-hydroxylaminopurine (HAP and 2-amino-6-hydroxylaminopurine (AHA, are strong mutagens in various organisms due to their ambiguous base-pairing properties. The systems protecting cells from HAP and related noncanonical purines in Escherichia coli include specialized deoxyribonucleoside triphosphatase RdgB, DNA repair endonuclease V, and a molybdenum cofactor-dependent system. Fewer HAP-detoxification systems have been identified in yeast Saccharomyces cerevisiae and other eukaryotes. Cellular systems protecting from AHA are unknown. In the present study, we performed a genome-wide search for genes whose deletions confer sensitivity to HAP and AHA in yeast. Results We screened the library of yeast deletion mutants for sensitivity to the toxic and mutagenic action of HAP and AHA. We identified novel genes involved in the genetic control of base analogs sensitivity, including genes controlling purine metabolism, cytoskeleton organization, and amino acid metabolism. Conclusion We developed a method for screening the yeast deletion library for sensitivity to the mutagenic and toxic action of base analogs and identified 16 novel genes controlling pathways of protection from HAP. Three of them also protect from AHA.

Assessment of the mutagenic and antimutagenic activity of Synadenium umbellatum Pax latex by micronucleus test in mice

Directory of Open Access Journals (Sweden)

PR. Melo-Reis

Full Text Available Synadenium umbellatum Pax, popularly known as "cola-nota", is a medicinal plant that grows in tropical regions. The latex of this plant is used against various diseases, such as diabetes mellitus, leprosy, tripanosomiasis, leukemia, and several malignant tumors. The mutagenic, antimutagenic, and cytotoxic effects of the latex of this plant were investigated by measuring the frequency of micronuclei in mice bone marrow cells. To evaluate mutagenicity, the animals were treated with four doses of latex (10, 30, 50, and 100 mg/kg body weight. To study the antimutagenic activity, the animals were simultaneously treated with latex and mitomycin C (4 mg/kg. The cytotoxicity was evaluated by polychromatic and normochromatic erythrocytes ratio. Our results showed a significant increase of frequency of micronucleated polychromatic erythrocytes (MNPCE compared to the negative control group (p 0.05 was detected at the doses of 50 and 100 mg/kg. Under our experimental conditions, the results obtained indicate strong mutagenic and cytotoxic activity of S. umbellatum latex except the dose of 10 mg/kg and moderate antimutagenic effect at lower doses.

Analysis of mutagenic DNA repair in a thermoconditional mutant of Saccharomyces cerevisiae. Pt. 3

International Nuclear Information System (INIS)

Siede, W.; Eckardt, F.

1986-01-01

Recent studies regarding the influence of cycloheximide on the temperature-dependent increase in survival and mutation frequencies of a thermoconditional rev2 mutant lead to the suggestion that the REV2-coded mutagenic repair function is UV-inducible. In the present study we show that stationary-phase rev2sup(ts) cells are characterized by a biphasic linear-quadratic dose-dependence of mutation induction ('mutation kinetics') of ochre alleles at 23 0 C (permissive temperature) but linear kinetics at the restrictive temperature of 36 0 C. Mathematical analysis using a model based on Poisson statistics and a further mathematical procedure, the calculation of 'apparent survival', support the assumption kinetics investigated can be attributed to a UV-inducible component of mutagenic DNA repair controlled by the REV2 gene. (orig.)

The inactivating and mutagenic effect of hydroxylamine on bacteriophage φX174

NARCIS (Netherlands)

Pol, J.H. van de; Arkel, G.A. van

1965-01-01

The inactivation of bacteriophage ΦXI74 by the mutagenic agents nitrous acid and ultraviolet irradiation proceeds according to a single-hit kinetics. However, treatment of purified ΦXI74 by hydroxylamine (HA) at pH 6 and 25° results in an inactivation that is not strictly exponential. The

Diesel exhaust particles are mutagenic in FE1-MutaMouse lung epithelial cells

DEFF Research Database (Denmark)

Jacobsen, Nicklas Raun; Møller, Peter; Cohn, Corey Alexander

2008-01-01

The particulate phase of diesel engine exhaust is likely carcinogenic. However, the mechanisms of diesel exhaust particles (DEPs) induced mutagenicity/carcinogenicity are still largely unknown. We determined the mutant frequency following eight repeated 72 h incubations with 37.5 or 75 microg...

Assessment of the mutagenic potential of hexavalent chromium in the duodenum of big blue® rats.

Science.gov (United States)

Thompson, Chad M; Young, Robert R; Dinesdurage, Harshini; Suh, Mina; Harris, Mark A; Rohr, Annette C; Proctor, Deborah M

2017-09-01

A cancer bioassay on hexavalent chromium Cr(VI) in drinking water reported increased incidences of duodenal tumors in B6C3F1 mice at exposures of 30-180ppm, and oral cavity tumors in F344 rats at 180ppm. A subsequent transgenic rodent (TGR) in vivo mutation assay in Big Blue® TgF344 rats found that exposure to 180ppm Cr(VI) in drinking water for 28days did not increase cII transgene mutant frequency (MF) in the oral cavity (Thompson et al., 2015). Herein, we extend our analysis to the duodenum of these same TgF344 rats. At study termination, duodenum chromium levels were below either the limit of detection or quantification in control rats, but were 24.6±3.8μg/g in Cr(VI)-treated rats. The MF in control (23.2×10 -6 ) and Cr(VI)-treated rats (22.7×10 -6 ) were nearly identical. In contrast, the MF in the duodenum of rats exposed to 1-ethyl-1-nitrosourea for six days (study days 1, 2, 3, 12, 19, 26) increased 24-fold to 557×10 -6 . These findings indicate that mutagenicity is unlikely an early initiating event in Cr(VI)-induced intestinal carcinogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Oxygen effect on mutagenic ionizing radiation damage in Bacillus subtilis spores of DNA polymerase I-proficient and -deficient strains

International Nuclear Information System (INIS)

Tanooka, H.

1980-01-01

The nature of mutagenic ionizing radiation damage modified by the presence of oxygen or water was examined by comparing mutagenic with lethal expression of the damage in Bacillus subtilis spores irradiated with 6-MeV electrons. No specific difference was recognized between oxygen-dependent and -independent damages or between polA + -dependent and -independent damages with this system. The induced mutation frequency for His + mutation per lethal hit was 4.7 x 10 -5 for all tested cases

Role of certain plant natural products or gamma radiation in the control of mutagenic activity of some heterocyclic amines

International Nuclear Information System (INIS)

Abu Ghadeer, A.R.M.; El-Sedeek, A.B.A.; Salem, A.M.; Abu Zaid, M.M.

1999-01-01

The present study was designed to use ames test to evaluate the antimutagenic effect of some natural products on the lever microsomes extracted from rats and incubated with some chemical mutagens (heterocyclic compounds). Male swiss albino rats (120-140 g) were used as the source of liver microsomes. Three natural products (Nigella extract, garlic powder and sesame oil) were used to evaluate their antimutagenic activities on six heterocyclic amines. All the tested natural products exhibited their antimutagenic activities when added to the investigated heterocyclic compounds and the most effective product was nigella sativa. another group of rats was exposed to gamma-radiation (6.5 Gy) for testing the validity of ames test in quantitating mutagenicity using liver microsomes of irradiated rats. Liver microsomes from irradiated rats showed to lose ability for metabolic activation needed for heterocyclic amines to exert their mutagenic effect on salmonella typhimurium

Hypersensitive responses of cells in the thymus, spleen, and intestinal crypt of mice to interphase death after treatment with x rays and chemical mutagens

International Nuclear Information System (INIS)

Kinuta, Masakatsu

1986-01-01

Upon whole-body exposure of mice to X rays or administration of chemical mutagens, cells in thymus, spleen and intestinal crypt undergo sensitive response to interphase death. We developed an effective method for detecting dead cells in the interphase by scoring stained cells in situ in exposed tissues after staining frozen section with erythrosin B. Cell killing was detected at doses as low as 1 % of lethal doses after treatment with X rays and chemicals. Strain N4 was highly sensitive to interphase-cell-death and hybrids of N4 and resistant strain HT or C3H were also sensitive to cell-death, indicating a dominant trait of the sensitive cell-death response. (author)

Low dose intoxication and a crisis of regulatory models. Chemical mutagens in the Deutsche Forschungsgemeinschaft (DFG), 1963-1973.

Science.gov (United States)

von Schwerin, Alexander

2010-12-01

Regulation and the prevention of danger are among the main characteristics of the modern state. However, the idea and the conceptualization of what danger is have changed over time. The genealogy of these changes shows that the history of social change and the history of knowledge are well connected. The 1970s marked the start of a social transformation of Western industrialized societies. This article proposes that this transformation was connected with basic epistemic reconfigurations and that the genealogy of risk played a significant role. This thesis is explored through the example of DFG advisory politics. Beginning in the 1960s, the DFG expert commissions that had been established to make policy and regulation recommendations began to focus more and more on the health effects of environmental pollution. The Commission for Questions of Mutagenicity played a particularly interesting role because its recommendations resulted in the foundation of a research institution run by the DFG, the Central Laboratory for Mutagenicity Testing (CML). The challenges faced by the CML in mutagenic research and testing effected a crisis of the expert-based advisory politics of the Mutagenicity Commission and a fundamental shift in the way scientific (regulatory) knowledge was perceived and valued politically. The pattern of this crisis calls to mind the constellation of the "risk society", but as will be shown, the (re)balancing of science and politics/society presented here is more adequately understood within the framework of political epistemology.

An evaluation of the mode of action framework for mutagenic carcinogens: chromium (VI)

Science.gov (United States)

In response to the 2005 revised U.S Environmental Protection Agency’s (EPA) Cancer Guidelines, a strategy is being developed to determine whether a carcinogen operates through a mutagenic mode of action (MOA). This information is necessary for EPA to decide whether age-dependent ...

The relative cytotoxicity and mutagenicity of cyclobutane pyrimidine dimers and photoproducts in Escherichia coli cells

International Nuclear Information System (INIS)

Tang, Moon-shong; Hrncir, J.; Mitchell, D.; Ross, J.; Clarkson, J.

1986-01-01

In order to calculate the relative cytotoxicity and mutagenicity of cyclobutane pyrimidine dimers and photoproducts, the authors have measured survival and mutation induction in UV-irradiated excision-deficient E. coli uvrA cells, with or without complete photoreactivation of the dimers. Radioimmunoassays with specificity for dimers or photoproducts have shown that maximum photoreactivation eliminates all of the dimers produce up to 10 Jm -2 254-nm light, while it has no effect on photoproducts. These results were confirmed by measuring the frequency of T4 endonuclease V-sensitive sites. Based on the best fit equations for survival and mutation induction, the authors have found that the calculated cytotoxicity of photoproducts is similar to that of dimers; however, the former is much more mutagenic than the latter. (Auth.)

Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae.

Science.gov (United States)

Toyoshima, Yoshiyuki; Takahashi, Akemi; Tanaka, Hisaki; Watanabe, Jun; Mogi, Yoshinobu; Yamazaki, Tatsuo; Hamada, Ryoko; Iwashita, Kazuhiro; Satoh, Katsuya; Narumi, Issay

2012-12-01

Aspergillus oryzae is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of A. oryzae were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was (12)C(5+) ion beams with an LET of 121keV/μm. The (12)C(5+) ion beams had a 3.6-times higher lethal effect than low-LET (0.2keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. (12)C(6+) ion beams with an LET of 86keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to (12)C(6+) ion beams increased with an increase in dose and reached 3.47×10(-3) at 700Gy. In the dose range from 0 to 700Gy, (12)C(5+) ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67×10(-3)) at 400Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (sB) and ATP sulfurylase gene (sC) loci, the loss of function of which results in a selenate resistant phenotype, were compared between (12)C(5+) ion beams and γ-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all cases. Although the incidence of deletions >2bp was generally low, deletions >20bp were characteristic for (12)C(5+) ion beams. γ-rays had a tendency to generate mutants carrying a multitude of mutations in the same locus. Both forms of radiation also induced genome-wide large-scale mutations including chromosome rearrangements and large deletions. These results provide new basic insights into the mutation breeding of A. oryzae using ionizing radiation. Crown Copyright © 2012. Published

Effects of chemical and physical mutagens on the frequency of a large genetic duplication in Salmonella typhimurium. II

International Nuclear Information System (INIS)

Hoffman, G.R.; Morgan, R.W.; Kirven, R.

1978-01-01

Strains of Salmonella typhimurium which contain a duplication of approximately 30% of the genome may be obtained by a simple selective procedure. These strains are highly unstable, losing the duplication when grown on non-selective medium. In this paper the authors report that treatment of merodiploid bacteria with mutagenic agents stimulates the rate at which haploid segregants are obtained from merodiploid strains. The mutagens which have been tested for this effect are X-rays, ultraviolet light (UV), ethyl methanesulfonate (EMS), and the azaacridine half-mustard ICR-372. (Auth.)

Improved mutagen-testing systems in mice. Progress report, 1 June 1975--31 May 1976

International Nuclear Information System (INIS)

Roderick, T.H.

1976-01-01

Progress is reported on the following research projects: detection of inversions; inversions produced by chemical mutagens and x radiation; phenotypic effects of inversions; linkage of inversions; cytology of inversions; Robertsonian metacentric translocations; and somatic crossing-over in mammals

M1 chimerism following mutagen treatment of seeds in rice and some other cereals

International Nuclear Information System (INIS)

Kawai, T.

1983-01-01

Articles reporting on M 1 chimerism following treatment of seed with mutagen in cereals were mostly published in the 1960's. Rice is a good material for making such studies because of its relatively large number of seeds per panicle, rather easily identifiable tillering and panicle branching systems and uniform growth after seedling transplanting. The present article summarizes results of studies on M 1 chimerism in rice and some other cereals which may serve as reference information in discussing M 1 chimerism of those plant species showing different development patterns, as dicotyledonous plants, following treatment of seed with mutagen. Studies on M 1 chimerism provide not only knowledge of the sporophyte development but also basic information for developing methods of harvesting M 2 seed which provide the maximum numbers of mutants of different origins in a limited number of M 2 plants. (author)

MUTAGENICITY AND DISINFECTION BY-PRODUCTS IN SURFACE DRINKING WATER DISINFECTED WITH PERACETIC ACID

Science.gov (United States)

The aims of this research were to study the influence of peracetic acid (PAA) on the formation of mutagens in surface waters used for human consumption and to assess its potential application for the disinfection of drinking water. The results obtained using PAA were compared to ...

Quasi-QSAR for mutagenic potential of multi-walled carbon-nanotubes.

Science.gov (United States)

Toropov, Andrey A; Toropova, Alla P

2015-04-01

Available on the Internet, the CORAL software (http://www.insilico.eu/coral) has been used to build up quasi-quantitative structure-activity relationships (quasi-QSAR) for prediction of mutagenic potential of multi-walled carbon-nanotubes (MWCNTs). In contrast with the previous models built up by CORAL which were based on representation of the molecular structure by simplified molecular input-line entry system (SMILES) the quasi-QSARs based on the representation of conditions (not on the molecular structure) such as concentration, presence (absence) S9 mix, the using (or without the using) of preincubation were encoded by so-called quasi-SMILES. The statistical characteristics of these models (quasi-QSARs) for three random splits into the visible training set and test set and invisible validation set are the following: (i) split 1: n=13, r(2)=0.8037, q(2)=0.7260, s=0.033, F=45 (training set); n=5, r(2)=0.9102, s=0.071 (test set); n=6, r(2)=0.7627, s=0.044 (validation set); (ii) split 2: n=13, r(2)=0.6446, q(2)=0.4733, s=0.045, F=20 (training set); n=5, r(2)=0.6785, s=0.054 (test set); n=6, r(2)=0.9593, s=0.032 (validation set); and (iii) n=14, r(2)=0.8087, q(2)=0.6975, s=0.026, F=51 (training set); n=5, r(2)=0.9453, s=0.074 (test set); n=5, r(2)=0.8951, s=0.052 (validation set). Copyright © 2014 Elsevier Ltd. All rights reserved.

Performance of mutagen treated Jatropha curcas (Petro-crop) on alkali soil

International Nuclear Information System (INIS)

Pandey, R.K.; Datta, S.K.; Mishra, P.N.

1998-01-01

Under the user land development programme, seeds of Jatropha curcas (Euphorbiaces) were treated with 6, 12, 18 and 24 krad of gamma rays and sown in randomised block design on different grades of alkali soils. Wide range of variability could be detected in mutagen treated population. Results indicate that suitable strains of J. curcas can be isolated through mutation breeding programme for utilisation of user land. (author)

Use of mutagenous factors in the breeding of vegetatively propagated plants

International Nuclear Information System (INIS)

Dryagina, I.V.; Fomenko, N.N.

1978-01-01

Given is a review of the literature and authors data on using mutagenous factors with different nature to breed some new and useful forms of plants reproduced vegetatively. The problem history and prospects of the practical application of the method are stated. In particular the data on ionizing radiation use in fruit crop selection to breed mutation forms (effect on buds, pollen, seeds etc.) are presented

The effect of green tea and olive oil on the mutagenic activity of heterocyclic amines extracted from common food consumed in Saudi Arabia.

Science.gov (United States)

Awney, Hala

2011-05-01

The effect of green tea (GT) and green tea with olive oil (GT+OL) as antioxidants on the formation and mutagenic activity of heterocyclic aromatic amines (HCAs) extracted from beef shawerma, grilled chicken and fried beef liver was examined. HCAs were extracted by blue rayon, analyzed as spiked and unspiked samples with high-performance liquid chromatography and its mutagenic response was assessed by Sallmonela typhimurium 100 in the Ames test. Surprisingly, GT and GT+OL augmented HCAs measured in beef shawerma and grilled chicken but total HCAs measured in GT+OL were less than GT treatment. Both treatments altered the HCA profile as imidazoquinoline type became the most abundant. In control and GT+OL fried beef liver no HCAs were detected, but Trp-P1 was detected in GT treatment. Generally, the mutagenic response of HCAs measured in GT+OL was less than GT in beef shawerma and grilled chicken. However, the mutagenic response of control and 2% GT+OL fried liver was negative. These data suggest that GT concentrations used in this study may induce free radical formation during the Millared reaction due to its pro-oxidative effect, which augmented the HCAs formed and its mutagenic response. In order to optimize both safety and quality of our diets, more need to be done to fully understand the risk of HCAs in food.

Impacts of Mixing on Acceptable Indoor Air Quality in Homes

Energy Technology Data Exchange (ETDEWEB)

Sherman, Max H.; Walker, Iain I.

2010-01-01

Ventilation reduces occupant exposure to indoor contaminants by diluting or removing them. In a multi-zone environment such as a house, every zone will have different dilution rates and contaminant source strengths. The total ventilation rate is the most important factor in determining occupant exposure to given contaminant sources, but the zone-specific distribution of exhaust and supply air and the mixing of ventilation air can play significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage, air distribution system, and contaminant source and occupant locations. Most U.S. and Canadian homes have central heating, ventilation, and air conditioning systems, which tend to mix the air; thus, the indoor air in different zones tends to be well mixed for significant fractions of the year. This article reports recent results of investigations to determine the impact of air mixing on exposures of residential occupants to prototypical contaminants of concern. We summarize existing literature and extend past analyses to determine the parameters than affect air mixing as well as the impacts of mixing on occupant exposure, and to draw conclusions that are relevant for standards development and for practitioners designing and installing home ventilation systems. The primary conclusion is that mixing will not substantially affect the mean indoor air quality across a broad population of occupants, homes, and ventilation systems, but it can reduce the number of occupants who are exposed to extreme pollutant levels. If the policy objective is to minimize the number of people exposed above a given pollutant threshold, some amount of mixing will be of net benefit even though it does not benefit average exposure. If the policy is to minimize exposure on average, then mixing air in homes is detrimental and should not be encouraged. We also conclude that most homes in the US have adequate mixing

Effects of physical and chemical mutagens on various quantitative traits in chickpea (Cicer arietinum L.)

International Nuclear Information System (INIS)

Wani, Aijaz A.; Anis, Mohammad

2004-01-01

Seeds of two chickpea varieties viz., Pusa-212 and Pusa-372 were subjected to 15, 20, 30 and 40 Kr doses of gamma rays and 0.1, 0.2, 0.3 and 0.4 per cent EMS treatment. A set of seeds of both the varieties irradiated at 20 Kr and 30 Kr was also subjected to treatment with EMS at 0.2, and 0.3 per cent. Data on eight quantitative traits viz., days taken to flowering and maturity, plant height (em), number of primary branches plant -1 , number of pods plant -1 , number of seeds pod -1 , 100-seed weight (g) and total seed yield plant -1 (g) were recorded for all the mutagenic treatments. The lower dose treatments in general, showed stimulatory effect whereas, higher treatments showed inhibitory effects on the mean performance of all the polygenic traits. Increase in C.V. in the mutagen treated population indicated that significant spectrum of phenotypic variability was created in all the polygenic traits in both the varieties. A comparison of the pooled effect of different levels of a particular mutagen on the mean value of various traits revealed that combination treatments proved to be most effective followed by EMS and gamma rays in inducing the magnitude of variability. The Var. Pusa 372 was comparatively more sensitive than the Var. Pusa-212. (author)

Exhaust gas emissions and mutagenic effects of modern diesel fuels, GTL, biodiesel and biodiesel blends

Energy Technology Data Exchange (ETDEWEB)

Munack, Axel; Ruschel, Yvonne; Schroeder, Olaf [Federal Research Institute for Rural Areas, Forestry and Fisheries, Braunschweig (Germany)], E-mail: axel.munack@vti.bund.de; Krahl, Juergen [Coburg Univ. of Applied Sciences (Germany); Buenger, Juergen [University of Bochum (Germany)

2008-07-01

Biodiesel can be used alone (B100) or blended with petroleum diesel in any proportion. The most popular biodiesel blend in the U.S.A. is B20 (20% biodiesel, 80% diesel fuel), which can be used for Energy Policy Act of 1992 (EPAct) compliance. In the European Union, the use of biofuel blends is recommended and was introduced by federal regulations in several countries. In Germany, biodiesel is currently blended as B5 (5% biodiesel) to common diesel fuel. In 2008, B7 plus three percent hydrotreated vegetable oil (HVO) as well is intended to become mandatory in Germany. To investigate the influence of blends on the emissions and possible health effects, we performed a series of studies with several engines (Euro 0, III and IV) measuring regulated and non-regulated exhaust compounds and determining their mutagenic effects. Emissions of blends showed an approximate linear dependence on the blend composition, in particular when regulated emissions are considered. However, a negative effect of blends was observed with respect to mutagenicity of the exhaust gas emissions. In detail, a maximum of the mutagenic potency was found in the range of B20. From this point of view, B20 must be considered as a critical blend, in case diesel fuel and biodiesel are used as binary mixtures. (author)

Dose-response and operational thresholds/NOAELs for in vitro mutagenic effects from DNA-reactive mutagens, MMS and MNU.

Science.gov (United States)

Pottenger, Lynn H; Schisler, Melissa R; Zhang, Fagen; Bartels, Michael J; Fontaine, Donald D; McFadden, Lisa G; Bhaskar Gollapudi, B

2009-08-01

The dose-response relationships for in vitro mutagenicity induced by methylmethanesulfonate (MMS) or methylnitrosourea (MNU) in L5178Y mouse lymphoma (ML) cells were examined. DNA adducts (N7-methylguanine, N7MeG and O(6)-methylguanine, O(6)MeG) were quantified as biomarkers of exposure. Both endpoints were assessed using 5replicates/dose (4-h treatment) with MMS or MNU (0.0069-50muM), or vehicle (1% DMSO). Mutant frequency (MF) (thymidine kinase (TK) locus) was determined using the soft agar cloning methodology and a 2-day expression period; in addition, microwell and Sequester-Express-Select (SES) methods were used for MMS. Isolated DNA was acid-hydrolyzed, and adducts quantified by LC/ESI-MS/MS, using authentic and internal standards. MF dose-responses were analyzed using several statistical approaches, all of which confirmed that a threshold dose-response model provided the best fit. NOAELs for MF were 10muM MMS and 0.69muM MNU, based on ANOVA and Dunnett's test (p/=10muM MMS or 3.45muM MNU. O(6)MeG levels were only quantifiable at >/=10muM MNU; O(6)MeG was not quantifiable in control or MMS-treated cells at current detection limits. Thus, (1) cells treated with MMS did not demonstrate increases in TK(-) MF, but did demonstrate quantifiable levels of N7MeG adducts; and (2) the levels of N7MeG adducts did not correlate with induced MF, as MNU-treated cells had fewer N7MeG adducts but higher MF compared with MMS-treated cells, for quasi-equimolar doses. Taken together, these results demonstrate operational thresholds, defined as the highest dose for which the response is not significantly (statistically or biologically) distinguishable from the control/background values, for induction of mutations and N7MeG adducts in ML cells treated with MMS or MNU, and a lack of correlation between induced MF and levels of N7MeG adducts.

Hyper production of alkaline protease by mutagenized bacillus subtilis

International Nuclear Information System (INIS)

Qureshi, A.M.; Tanseem, F.

2010-01-01

The purpose of this work was to augment the alkaline protease production from Bacillus subtilis by using chemical mutagen (MMS) and UV mutagenesis. A number of mutants were isolated which produce high levels of extra cellular proteases. Analysis of culture supernatants of these mutants had shown that the total amounts of proteolysis activity were increased from 1 to 2 fold over the wild strain. Clones showing promote response were further characterized by analyzing different parameters; like of Temperature, pH substrate concentration and incubation period, to study the activity of protease enzyme. (author)

Cytotoxic, phytotoxic, and mutagenic appraisal to ascertain toxicological potential of particulate matter emitted from automobiles.

Science.gov (United States)

Anwar, Khaleeq; Ejaz, Sohail; Ashraf, Muhammad; Altaf, Imran; Anjum, Aftab Ahmad

2013-07-01

Vehicular air pollution is a mounting health issue of the modern age, particularly in urban populations of the developing nations. Auto-rickshaws are not considered eco-friendly as to their inefficient engines producing large amount of particulate matter (PM), thus posing significant environmental threat. The present study was conducted to ascertain the cytotoxic, phytotoxic, and mutagenic potential of PM from gasoline-powered two-stroke auto-rickshaws (TSA) and compressed natural gas-powered four-stroke auto-rickshaws (FSA). Based on the increased amount of aluminum quantified during proton-induced X-ray emission analysis of PM from TSA and FSA, different concentrations of aluminum sulfate were also tested to determine its eco-toxicological potential. The MTT assay demonstrated significant (p < 0.001) dose-dependent cytotoxic effects of different concentrations of TSA, FSA, and aluminum sulfate on BHK-21 cell line. LC50 of TSA, FSA, and aluminum sulfate was quantified at 16, 11, and 23.8 μg/ml, respectively, establishing PM from FSA, a highly cytotoxic material. In case of phytotoxicity screening using Zea mays, the results demonstrated that all three tested materials were equally phytotoxic at higher concentrations producing significant reduction (p < 0.001) in seed germination. Aluminum sulfate proved to be a highly phytotoxic agent even at its lowest concentration. Mutagenicity was assessed by fluctuation Salmonella reverse mutation assay adopting TA100 and TA98 mutant strains with (+S9) and without (-S9) metabolic activation. Despite the fact that different concentrations of PM from both sources, i.e., TSA and FSA were highly mutagenic (p < 0.001) even at lower concentrations, the mutagenic index was higher in TSA. Data advocate that all tested materials are equally ecotoxic, and if the existing trend of atmospheric pollution by auto-rickshaws is continued, airborne heavy metals will seriously affect the normal growth of local inhabitants and

Spontaneous and mutagen-induced deletions: mechanistic studies in Salmonella tester strain TA102

International Nuclear Information System (INIS)

Levin, D.E.; Marnett, L.J.; Ames, B.N.

1984-01-01

Salmonella tester strain TA102 carries the hisG428 ochre mutation on the multicopy plasmid pAQ1. DNA sequence analysis of 45 spontaneous revertants of hisG428 on the chromosome in the presence of pKM101 (strain TA103) indicates that hisG428 revertants fall into three major categories: (i) small, in-frame deletions (3 or 6 base pairs) that remove part or all of the ochre triplet; (ii) base substitution mutations at the ochre site; (iii) extragenic ochre suppressors. Deletion revertants are identified in a simple phenotypic screen by their resistance to the inhibitory histidine analog thiazolealanine, which feedback inhibits the wild-type hisG enzyme but not the enzyme resulting from the deletions. The effect of various genetic backgrounds on the generation of spontaneous deletion revertants was examined. The presence of a uvrB mutation or a recA mutation suppressed the generation of spontaneous deletion revertants to approximately 1/2.5. When hisG428 was in multiple copies on pAQ1, the frequency of spontaneous deletion revertants increased by 40-fold, which is the approximate copy number of pAQ1. Mutagenic agents that induce single-strand breaks in DNA (e.g., x-rays, bleomycin, and nalidixic acid) induced deletion revertants in TA102. These agents induced deletion revertants only in hisG428 on pAQ1 and only in the presence of pKM101. Deletion revertants were not induced by frameshift mutagens (i.e., ICR-191 and 9aminoacridine). These results indicate that different pathways exist for the generation of spontaneous and mutagen-induced deletion revertants of hisG428. 41 references, 2 figures, 3 tables

Urinary 1-hydroxypyrene and mutagenicity in bus drivers and mail carriers exposed to urban air pollution in Denmark

DEFF Research Database (Denmark)

Hansen, Åse Marie; Wallin, Håkan; Binderup, Mona Lise

2004-01-01

BACKGROUND: Previous studies in Denmark have shown that bus drivers and tramway employees were at an increased risk for developing several types of cancer and that bus drives from central Copenhagen have high levels of biomarkers of DNA damage.AIMS: The present study evaluates 1-hydroxypyrene....../mol creatinine [CI: 0.37-1.47] and female bus drivers 1.90 revertants/mol creatinine [CI: 1.01-2.79] higher mutagenic activity in urine than mail carriers. CONCLUSION: The present study indicates that bus drivers are more exposed to polycyclic aromatic hydrocarbons (PAH) and mutagens than mail carriers. Mail...

A multi-step process of viral adaptation to a mutagenic nucleoside analogue by modulation of transition types leads to extinction-escape.

Directory of Open Access Journals (Sweden)

Rubén Agudo

2010-08-01

Full Text Available Resistance of viruses to mutagenic agents is an important problem for the development of lethal mutagenesis as an antiviral strategy. Previous studies with RNA viruses have documented that resistance to the mutagenic nucleoside analogue ribavirin (1-β-D-ribofuranosyl-1-H-1,2,4-triazole-3-carboxamide is mediated by amino acid substitutions in the viral polymerase that either increase the general template copying fidelity of the enzyme or decrease the incorporation of ribavirin into RNA. Here we describe experiments that show that replication of the important picornavirus pathogen foot-and-mouth disease virus (FMDV in the presence of increasing concentrations of ribavirin results in the sequential incorporation of three amino acid substitutions (M296I, P44S and P169S in the viral polymerase (3D. The main biological effect of these substitutions is to attenuate the consequences of the mutagenic activity of ribavirin -by avoiding the biased repertoire of transition mutations produced by this purine analogue-and to maintain the replicative fitness of the virus which is able to escape extinction by ribavirin. This is achieved through alteration of the pairing behavior of ribavirin-triphosphate (RTP, as evidenced by in vitro polymerization assays with purified mutant 3Ds. Comparison of the three-dimensional structure of wild type and mutant polymerases suggests that the amino acid substitutions alter the position of the template RNA in the entry channel of the enzyme, thereby affecting nucleotide recognition. The results provide evidence of a new mechanism of resistance to a mutagenic nucleoside analogue which allows the virus to maintain a balance among mutation types introduced into progeny genomes during replication under strong mutagenic pressure.

Micronuclei frequency in children exposed to environmental mutagens: a review

DEFF Research Database (Denmark)

Neri, Monica; Fucic, Aleksandra; Knudsen, Lisbeth E

2003-01-01

Cytogenetic monitoring has been traditionally used for the surveillance of populations exposed to genotoxic agents. In recent years sensitivity problems emerged in surveys of populations exposed to low levels of mutagens, and therefore alternative approaches have been explored. Biomonitoring....... The limited number of published papers indicates that the conduct of properly designed studies on the effect of environmental pollutants in children may be difficult. This review confirmed the usefulness of MN assay in biomonitoring studies conducted in children, revealing that in many circumstances...

The photoreactivable component in the mutagenic action of ionizing radiations

International Nuclear Information System (INIS)

Myasnik, M.N.; Morozov, I.I.; Derevyanko, R.I.

1980-01-01

The influence of visible light on the lethal and the mutagenic effects of gamma-radiation on E. coli WP 2 uvrA + and E. coli WP 2 uvrA cells was studied. It was shown that visible light appears to reduce the yield of gamma-induced prototrophs in E. coli WP 2 uvrA cells while the yield of prototrophs in E. coli WP 2 uvrA + stays unchanged. Visible light did not change the survival of gamma-irradiated cells. (author)

Topology of evolving, mutagenized viral populations: quasispecies expansion, compression, and operation of negative selection.

Science.gov (United States)

Ojosnegros, Samuel; Agudo, Rubén; Sierra, Macarena; Briones, Carlos; Sierra, Saleta; González-López, Claudia; Domingo, Esteban; Cristina, Juan

2008-07-17

The molecular events and evolutionary forces underlying lethal mutagenesis of virus (or virus extinction through an excess of mutations) are not well understood. Here we apply for the first time phylogenetic methods and Partition Analysis of Quasispecies (PAQ) to monitor genetic distances and intra-population structures of mutant spectra of foot-and-mouth disease virus (FMDV) quasispecies subjected to mutagenesis by base and nucleoside analogues. Phylogenetic and PAQ analyses have revealed a highly dynamic variation of intrapopulation diversity of FMDV quasispecies. The population diversity first suffers striking expansions in the presence of mutagens and then compressions either when the presence of the mutagenic analogue was discontinued or when a mutation that decreased sensitivity to a mutagen was selected. The pattern of mutations found in the populations was in agreement with the behavior of the corresponding nucleotide analogues with FMDV in vitro. Mutations accumulated at preferred genomic sites, and dn/ds ratios indicate the operation of negative (or purifying) selection in populations subjected to mutagenesis. No evidence of unusually elevated genetic distances has been obtained for FMDV populations approaching extinction. Phylogenetic and PAQ analysis provide adequate procedures to describe the evolution of viral sequences subjected to lethal mutagenesis. These methods define the changes of intra-population structure more precisely than mutation frequencies and Shannon entropies. PAQ is very sensitive to variations of intrapopulation genetic distances. Strong negative (or purifying) selection operates in FMDV populations subjected to enhanced mutagenesis. The quantifications provide evidence that extinction does not imply unusual increases of intrapopulation complexity, in support of the lethal defection model of virus extinction.

Dietary Intake of Meat Cooking-Related Mutagens (HCAs) and Risk of Colorectal Adenoma and Cancer: A Systematic Review and Meta-Analysis

OpenAIRE

Chiavarini, Manuela; Bertarelli, Gaia; Minelli, Liliana; Fabiani, Roberto

2017-01-01

Much evidence suggests that the positive association between meat intake and colorectal adenoma (CRA) and cancer (CRC) risk is mediated by mutagenic compounds generated during cooking at high temperature. A number of epidemiological studies have estimated the effect of meat-related mutagens intake on CRC/CRA risk with contradictory and sometimes inconsistent results. A literature search was carried out (PubMed, Web of Science and Scopus) to identify articles reporting the relationship between...

Stable isotope dilution quantification of mutagens in cooked foods by combined liquid chromatography-thermospray mass spectrometry

International Nuclear Information System (INIS)

Yamaizumi, Ziro; Kasai, Hiroshi; Nishimura, Susumu; Edmonds, C.G.; McCloskey, J.A.

1986-01-01

A method of general applicability for the detection and quantification of mutagens in cooked foods at the ppb level is presented. A minimal sample prefractionation is employed and [Me- 2 H 3 ]-labeled analogs of the compounds of interest are added for identification and quantification of mutagens by accurate measurement of chromatographic retention (K') in reverse-phase high-performance liquid chromatography (HPLC), and by measurement of the ratio of response of the protonated molecular ions of analyte and internal standard by directly coupled liquid chromatography-mass spectrometry (LC/MS). Initial application is demonstrated in the analysis of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MelQ) in broiled salmon. (Auth.)

An evaluation of the mode of action framework for mutagenic carcinogens: Chromium (VI): SOT.

Science.gov (United States)

In response to the 2005 revised U.S Environmental Protection Agency’s (EPA) Cancer Guidelines, a strategy is being developed to determine whether a carcinogen operates through a mutagenic mode of action (MOA). This information is necessary for EPA to decide whether age-dependent ...

Mutagenic effect of gamma-rays on improvement of yield attributing traits of greengram (Vigna radiata (L.) Wilczek)

International Nuclear Information System (INIS)

Das, T.R.; Baisakh, B.

2014-01-01

Seed samples of two morphologically distinct varieties (Sujata and OBGG-52) of greengram were treated with three doses of Gamma-rays (200 Gy, 400 Gy and 600 Gy). Mutagenic treatments in general showed reduction in mean values of germination, survival and plant growth traits in comparison to control in M 1 generation and the magnitude of reduction was directly related to the dose of the mutagens. The spectrum of chlorophyll mutations includes albina, xantha, chlorina, striata and viridis in both the varieties. The varied morphological mutations observed in leaf of both the genotypes were tricotyledonary, quadrifoliate, pentafoliate and lobed leaf. Early flowering, late flowering, tall plant, trailing type, profused poded, bold poded and sterile plant were also observed as an effect of mutagen in both the genotypes. The M 2 populations showed wider range of variations than the parent varieties. Magnitude of changes varied with mutagen dose and the varieties. Higher the dose of treatment, greater the shift in the mean and variance of different yield parameters. Genetic advance estimates showed that selection in M 2 populations would be effective in improving the yield/plant. Following selection among M 2 plants and M 3 progenies on the basis of higher yield, high yielding mutant cultures in both varieties were isolated in M 4 and evaluated in M 5 generation. Gamma-ray dose of 200 Gy was most effective for improving the yield traits in both the genotypes as it brought out improvement in pods/plant, pod length and 100-seed wt. where as 400 Gy improved 100- seed wt. in only Sujata and 600 Gy improved pod length and seeds/pod only. Isolation of high yielding lines from the gamma-rays treated population of greengram proved that different doses of gamma rays induced improvement of different yield attributing characters in greengram. (author)

Effect of physical and chemical mutagens on seed germination and survival of seedling in Lycopersicon esculentum Mill

International Nuclear Information System (INIS)

Jayabalan, N.; Rao, G.R.

1987-01-01

Dry and healthy seeds of Lycopersicon esculentum Mill. var. Co-2 were irradiated with gamma rays at 10 KR, 20 KR, 30 KR, 40 KR and 50 KR. The percentage of seed germination was directly proportional to the dose given. The survival percentage decreased with higher doses. Concentration of EMS and NMU applied, ranged from 10 mM to 50 mM and 1 mM to 5 mM, respectively. The duration of soaking of seed was 4 hours in distilled water and 4 hours in mutagenic agents. In treated seeds, the percentage of germination and survival of seedlings decreased with an increase in concentration of these chemical mutagens. These observations are discussed in detail. (author). 11 refs

Reduction of hexavalent chromium by fasted and fed human gastric fluid. I. Chemical reduction and mitigation of mutagenicity

Energy Technology Data Exchange (ETDEWEB)

De Flora, Silvio, E-mail: sdf@unige.it [Department of Health Sciences, University of Genoa, 16132 Genoa (Italy); Camoirano, Anna, E-mail: Anna.Fiorenza.Camoirano@unige.it [Department of Health Sciences, University of Genoa, 16132 Genoa (Italy); Micale, Rosanna T., E-mail: rosannamicale@yahoo.it [Department of Health Sciences, University of Genoa, 16132 Genoa (Italy); La Maestra, Sebastiano, E-mail: lamaestra78@yahoo.it [Department of Health Sciences, University of Genoa, 16132 Genoa (Italy); Savarino, Vincenzo, E-mail: vsavarin@unige.it [Gastroenterology Unit, Department of Internal Medicine, University of Genoa, 16132 Genoa (Italy); Zentilin, Patrizia, E-mail: Patrizia.Zentilin@unige.it [Gastroenterology Unit, Department of Internal Medicine, University of Genoa, 16132 Genoa (Italy); Marabotto, Elisa, E-mail: emarabotto@libero.it [Gastroenterology Unit, Department of Internal Medicine, University of Genoa, 16132 Genoa (Italy); Suh, Mina, E-mail: msuh@toxstrategies.com [ToxStrategies, Mission Viejo, CA 92692 (United States); Proctor, Deborah M., E-mail: dproctor@toxstrategies.com [ToxStrategies, Mission Viejo, CA 92692 (United States)

2016-09-01

Evaluation of the reducing capacity of human gastric fluid from healthy individuals, under fasted and fed conditions, is critical for assessing the cancer hazard posed by ingested hexavalent chromium [Cr(VI)] and for developing quantitative physiologically-based pharmacokinetic models used in risk assessment. In the present study, the patterns of Cr(VI) reduction were evaluated in 16 paired pre- and post-meal gastric fluid samples collected from 8 healthy volunteers. Human gastric fluid was effective both in reducing Cr(VI), as measured by using the s-diphenylcarbazide colorimetric method, and in attenuating mutagenicity in the Ames test. The mean (± SE) Cr(VI)-reducing ability of post-meal samples (20.4 ± 2.6 μg Cr(VI)/mL gastric fluid) was significantly higher than that of pre-meal samples (10.2 ± 2.3 μg Cr(VI)/mL gastric fluid). When using the mutagenicity assay, the decrease of mutagenicity produced by pre-meal and post-meal samples corresponded to reduction of 13.3 ± 1.9 and 25.6 ± 2.8 μg Cr(VI)/mL gastric fluid, respectively. These data are comparable to parallel results conducted by using speciated isotope dilution mass spectrometry. Cr(VI) reduction was rapid, with > 70% of total reduction occurring within 1 min and 98% of reduction is achieved within 30 min with post-meal gastric fluid at pH 2.0. pH dependence was observed with decreasing Cr(VI) reducing capacity at higher pH. Attenuation of the mutagenic response is consistent with the lack of DNA damage observed in the gastrointestinal tract of rodents following administration of ≤ 180 ppm Cr(VI) for up to 90 days in drinking water. Quantifying Cr(VI) reduction kinetics in the human gastrointestinal tract is necessary for assessing the potential hazards posed by Cr(VI) in drinking water. - Highlights: • Cr(VI) reduction capacity was greater in post-meal than paired pre-meal samples. • Cr(VI) reduction was rapid, pH dependent, and due to heat stable components. • Gastric fluid attenuates

In vivo evaluation of the mutagenic potential and phytochemical characterization of oleoresin from Copaifera duckei Dwyer

Directory of Open Access Journals (Sweden)

Edson Luis Maistro

2005-12-01

Full Text Available We characterized the chemical constituents of Copaifera duckei oleoresin and used dermal application to Wistar rats to evaluated its possible mutagenic and cytotoxic activities on peripheral blood reticulocytes and bone marrow cells. Chemical characterization of the oleoresin revealed the presence of sesquiterpene hydrocarbons, an unidentified neutral diterpene and diterpene acids. To evaluate mutagenicity evaluation the rats were treated with 10, 25 and 50% of the LD50 dose of the oleoresin for three consecutive days and peripheral blood collected after 0, 24, 48 and 72 h for micronucleus analysis. The rats were humanly sacrificed 24 hours after the last treatment and chromosome preparations made using standard techniques. At the three concentrations and the three time intervals tested we found that there were no statistically significant differences in either the mean number of micronucleated reticulocytes (MNRETs or the number of chromosomal aberrations as to the negative control. However, at 25 and 50% of the LD50 dose of the oleoresin there was a significant decrease in the mitotic index (MI as compared to the negative control. Under our experimental conditions, C. duckei V11 oleoresin produced no mutagenic effects on bone marrow cells or in peripheral reticulocytes as assessed by chromosome aberrations and the micronucleus test respectively, but showed cytotoxic activity at high doses.

Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to X-rays.

Science.gov (United States)

Varès, Guillaume; Wang, Bing; Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru

2011-01-10

The ability of cells to adapt low-dose or low-dose rate radiation is well known. High-LET radiation has unique characteristics, and the data concerning low doses effects and high-LET radiation remain fragmented. In this study, we assessed in vitro the ability of low doses of X-rays to induce an adaptive response (AR) to a subsequent challenging dose of heavy-ion radiation. Lymphoblastoid cells (TK6, AHH-1, NH32) were exposed to priming 0.02-0.1Gy X-rays, followed 6h later by challenging 1Gy heavy-ion radiation (carbon-ion: 20 and 40keV/μm, neon-ion: 150keV/μm). Pre-exposure of p53-competent cells resulted in decreased mutation frequencies at hypoxanthine-guanine phosphoribosyl transferase locus and different H2AX phosphorylation kinetics, as compared to cells exposed to challenging radiation alone. This phenomenon did not seem to be linked with cell cycle effects or radiation-induced apoptosis. Taken together, our results suggested the existence of an AR to mutagenic effects of heavy-ion radiation in lymphoblastoid cells and the involvement of double-strand break repair mechanisms. Copyright © 2010 Elsevier B.V. All rights reserved.

Monitoring ambient air for mutagenicity using the higher plant Tradescantia

International Nuclear Information System (INIS)

Schairer, L.A.; Sautkulis, R.C.; Tempel, N.R.

1982-01-01

The major emphasis for short-term bioassays has been placed on bacterial and mammalian cell lines. However, for increased perspective on the state-of-the-art of specific in vitro assays it is important to consider the environmental impact on whole organisms by reviewing the contributions made by in vivo assays. This paper will deal exclusively with somatic mutation in the Tradescantia stamen hair: describing the system briefly, demonstrating its relevance to environmental mutagen assessment and discussing its adaptation for in situ ambient atmosphere monitoring

Examination of Mutagenic Effects of GAL-57 Herbicide (Bentazone+Dicamba Using Mouse Micronucleus Test

Directory of Open Access Journals (Sweden)

Vesela Karan

2007-01-01

Full Text Available A micronucleus test was run to investigate mutagenic potential of the herbicide GAL-57, a formulated mixture of bentazone and dicamba.The test was applied to mice of both sexes (strain: CRL: NMRI BR and the herbicide (product was administered by gavage at 2000 mg/kg rate, twice within 24 hs. Cyclophosphamide (positive control was administered at 60 mg/kg, while distilled water as a solvent was negative control. The animals were sacrificed 24 hs after second treatment, their bone marrow cells isolated from femur, and effects evaluated.The data acquired showed that repeated treatment of mice with GAL-57 caused neither biological nor significant statistical increase in the number of micronuclei in treated animals. At the same time, the number of micronucleated polychromatic erythrocytes in the bone marrow of animals treated with cyclophosphamide (positive control showed a significant statistical increase. The results suggest that the herbicide product tested did not show any mutagenic activity under the conditions of mouse micronucleus test.

Effect of Increased Water Intake on Urinary DNA Adduct Levels and Mutagenicity in Smokers: A Randomized Study

Directory of Open Access Journals (Sweden)

Inmaculada Buendia Jimenez

2015-01-01

Full Text Available The association between fluid intake and bladder cancer risk remains controversial. Very little is known about to which extent the amount of water intake influences the action of excreting toxics upon the urinary system. This proof of concept trial investigates the effect of water intake on mutagenesis in smokers, a high risk population for bladder cancer. Methods. Monocentric randomized controlled trial. Inclusion Criteria. Male subjects aged 2045–45 y/o, smokers, and small drinkers (24-hour urinary volume 700 mOsmol/kg. Outcomes. 4-ABP DNA adducts formation in exfoliated bladder cells in 24-hour urine collection and urinary mutagenicity in 24-hour urine. Test Group. Subjects consumed 1.5 L daily of the study product (EVIAN on top of their usual water intake for 50 days. Control Group. Subjects continued their usual lifestyle habits. Results. 65 subjects were randomized. Mean age was 30 y/o and mean cigarettes per day were 20. A slight decrease in adducts formation was observed between baseline and last visit but no statistically significant difference was demonstrated between the groups. Urinary mutagenicity significantly decreased. The study shows that increasing water intake decreases urinary mutagenicity. It is not confirmed by urinary adducts formation. Further research would be necessary.

Characterization of urban aerosol: seasonal variation of mutagenicity and genotoxicity of PM2.5, PM1 and semi-volatile organic compounds.

Science.gov (United States)

Bocchi, Clara; Bazzini, Cristina; Fontana, Federica; Pinto, Giancarlo; Martino, Anna; Cassoni, Francesca

2016-10-01

Urban particulate matter (PM) is an environmental public health concern as it has been classified by the IARC as carcinogenic to humans (group 1) and it's well known that pollutants are more associated with the finest fractions of PM. In this study we characterize urban aerosol in Bologna, county town of Emilia-Romagna in the north of Italy, collecting PM 2.5 , PM 1 and semi-volatile organic compounds using polyurethane foam. Samples were collected in three different seasons (winter, summer and autumn) and were extracted with acetone. On these three fractions we assessed mutagenicity using Salmonella reverse mutation test and genotoxicity by alkaline comet assay and micronucleus assay in human lung cancer cell line, A549. Organic extracts were also characterized for alkanes, polycyclic aromatic hydrocarbons (PAHs), nitrated and oxygenated PAHs. We also evaluated associations between the physicochemical parameters of samples and their genotoxicity. The particulate samples, collected in autumn and winter, indicated the presence of both base pair substitution and frameshift mutagens using TA98 and TA100 strains of Salmonella typhimurium and the mutagenicity was more associated with the finest fraction. Enhanced mutagenic response was observed in the absence of enzyme activation. Only a third of comet and a half of micronucleus assays gave positive results that, unlike Salmonella's ones, are not season-related. These results were compared with environmental chemicals concentrations and we found that Salmonella's data correlated with PAHs detected on PM filters and with mass concentrations, whereas the DNA damage correlate only with PAHs extracted from polyurethane foams. The use of different assays was sensitive to detect and identify different classes of airborne mutagenic/genotoxic compounds present in aerosol, showing that monitoring air quality using this methodology is relevant. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of mutagen application of sodium azide and gamma radiation in rice seeds

International Nuclear Information System (INIS)

Guimaraes, E.P.

1980-01-01

Effects of mutagen application of sodium azide and gamma radiation in rice seeds. Upland rice seeds, variety Dourado Precoce, were treated with gamma-rays and sodium azide(SA). Biological effects of these treatments were studied in the M 1 and M 2 generations. Survival number, seedling height, plant fertility and chlorophyill mutation frequencies based on mutations per 100 M 1 panicles and mutants per 100 M 2 seedlings were analysed. Among these characters, plant fertility was the most sensitive for mutagen treatments, and higher doses of gamma-rays or higher concentrations of sodium azide reduced significantly fertility of M 1 plants. The same effect as increase of concentration of sodium azide was observed when the acidity of buffer solution was increased, or when seeds were pre-treated in distilled water. The maximum chlorophyll mutation frequencies were obtained in sodium azide treatments: 40.74% in the M 1 panicles and 10.67% in the M 2 seedlings, in comparison with the maximum frequenies in gamma-irradiation of 10.39% in the M 1 panicles and 1.73% in the M 2 seedlings. (Author) [pt

Mutagenic treatments towards increasing the frequency of day-neutral mutations and standardization of procedures for tissue culture, in potato

International Nuclear Information System (INIS)

Upadhya, M.D.; Chandra, R.; Abraham, M.J.

1976-01-01

Various chemical mutagens and gamma radiation have been used on single dormant eyes and true seeds with a view to finding effective mutagenic treatment for the induction of day-length neutral mutants in potato using an effective screening technique for the isolation of day-length neutral mutants. Sodium meta bisulphite (SMS) was found to be an efficient mutagen in inducing mutations for this trait in true seeds although the same concentrations, when used for treating the single tuber eyes proved lethal. Pre-soaking the seeds for 24 hrs prior to treatment with 0.0025M SMS gave highest frequency of the mutants followed by 48 hrs presoaking, indicating a sensitive stage during the cell cycle in true seeds. Other mutagen treatments gave different frequencies of mutations. The highest frequency of day-length neutral mutants was observed when seeds irradiated with 40 Kr of gamma radiation were treated with 0.05M hydrazinium dichloride solution. Screening procedures have also been standardised with the development of synethetic media for the isolation of biochemical mutants at the true seed level. Initial efforts have yielded mutants resistant to LD 100 doses of ethionine. Another aspect of the study was to develop a proper potato callus culture technique. A medium has been developed to produce and maintain callus from potato leaf strips. Efforts on the regeneration of shoot and roots from callus, have so far lead to differentiation of callus to form roots. The ultimate aim of these studies is to develop plantlets from single cell which would form the units of mutation induction and isolation. (author)

Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.**

Science.gov (United States)

We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.

Science.gov (United States)

We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

Carcinogens, Teratogens and Mutagens: Their Impact on Occupational Health, Particularly for Women in Veterinary Medicine.

Science.gov (United States)

Milligan, J. E.; And Others

1983-01-01

Pregnant women, especially those working in veterinary medicine, face occupational health/disease risks from mutagens, teratogens, and carcinogens. These hazards can be placed into three categories: physical, chemical, and biological. Each of these hazards is discussed with examples. (Author/JN)

Two-dimensional IR spectroscopy of the anti-HIV agent KP1212 reveals protonated and neutral tautomers that influence pH-dependent mutagenicity.

Science.gov (United States)

Peng, Chunte Sam; Fedeles, Bogdan I; Singh, Vipender; Li, Deyu; Amariuta, Tiffany; Essigmann, John M; Tokmakoff, Andrei

2015-03-17

Antiviral drugs designed to accelerate viral mutation rates can drive a viral population to extinction in a process called lethal mutagenesis. One such molecule is 5,6-dihydro-5-aza-2'-deoxycytidine (KP1212), a selective mutagen that induces A-to-G and G-to-A mutations in the genome of replicating HIV. The mutagenic property of KP1212 was hypothesized to originate from its amino-imino tautomerism, which would explain its ability to base pair with either G or A. To test the multiple tautomer hypothesis, we used 2D IR spectroscopy, which offers subpicosecond time resolution and structural sensitivity to distinguish among rapidly interconverting tautomers. We identified several KP1212 tautomers and found that >60% of neutral KP1212 is present in the enol-imino form. The abundant proportion of this traditionally rare tautomer offers a compelling structure-based mechanism for pairing with adenine. Additionally, the pKa of KP1212 was measured to be 7.0, meaning a substantial population of KP1212 is protonated at physiological pH. Furthermore, the mutagenicity of KP1212 was found to increase dramatically at pH KP1212 molecules. Overall, our data reveal that the bimodal mutagenic properties of KP1212 result from its unique shape shifting ability that utilizes both tautomerization and protonation.

A re-circulated toxicity exposure chamber to evaluate hydrocarbon dispersions

International Nuclear Information System (INIS)

Fuller, C.B.; Bonner, J.S.; Bujnoch, J.D.; Ussery, S.F.; Arrambide, G.; Sterling, M.C.

2002-01-01

Traditional toxicology methods are not suitable for evaluating chemically dispersed oil which exists mostly as a colloidal suspension and as dissolved fractions. A new toxicity exposure chamber was designed with separate chambers for scaled mixing and organism exposure. The design of the chamber incorporates continuous recirculation between the mixing and exposure chamber and an upward flow in the exposure chamber. The toxicity exposure system incorporates scalable and quantitative mixing inputs with real time particle size analysis and traditional petrochemistry methods to characterize the exposure regime. Changes in dispersion were successfully translated to the organism exposure regime. The study determined the petroleum toxicity with a juvenile marine test species. Low control mortality demonstrated the usefulness of the method for testing toxicity of colloidal oil suspensions. 20 refs., 1 tab., 4 figs

Topology of evolving, mutagenized viral populations: quasispecies expansion, compression, and operation of negative selection

Directory of Open Access Journals (Sweden)

Sierra Saleta

2008-07-01

Full Text Available Abstract Background The molecular events and evolutionary forces underlying lethal mutagenesis of virus (or virus extinction through an excess of mutations are not well understood. Here we apply for the first time phylogenetic methods and Partition Analysis of Quasispecies (PAQ to monitor genetic distances and intra-population structures of mutant spectra of foot-and-mouth disease virus (FMDV quasispecies subjected to mutagenesis by base and nucleoside analogues. Results Phylogenetic and PAQ analyses have revealed a highly dynamic variation of intrapopulation diversity of FMDV quasispecies. The population diversity first suffers striking expansions in the presence of mutagens and then compressions either when the presence of the mutagenic analogue was discontinued or when a mutation that decreased sensitivity to a mutagen was selected. The pattern of mutations found in the populations was in agreement with the behavior of the corresponding nucleotide analogues with FMDV in vitro. Mutations accumulated at preferred genomic sites, and dn/ds ratios indicate the operation of negative (or purifying selection in populations subjected to mutagenesis. No evidence of unusually elevated genetic distances has been obtained for FMDV populations approaching extinction. Conclusion Phylogenetic and PAQ analysis provide adequate procedures to describe the evolution of viral sequences subjected to lethal mutagenesis. These methods define the changes of intra-population structure more precisely than mutation frequencies and Shannon entropies. PAQ is very sensitive to variations of intrapopulation genetic distances. Strong negative (or purifying selection operates in FMDV populations subjected to enhanced mutagenesis. The quantifications provide evidence that extinction does not imply unusual increases of intrapopulation complexity, in support of the lethal defection model of virus extinction.

Kinetic characterization of glucose aerodehydrogenase from Aspergillus niger EMS-150-F after optimizing the dose of mutagen for enhanced production of enzyme

OpenAIRE

Umbreen, Huma; Zia, Muhammad Anjum; Rasul, Samreen

2013-01-01

In the present study enhanced production of glucose aerodehydrogenase from Aspergillus niger has been achieved after optimizing the dose of chemical mutagen ethyl methane sulfonate (EMS) that has not been reported earlier. Different doses of mutagen were applied and a strain was developed basing upon the best production. The selected strain Aspergillus niger EMS-150-F was optimized for nutrient requirements in order to produce enzyme through fermentation and the results showed the best yield ...

Mutagenic and carcinogenic structural alerts and their mechanisms of action.

Science.gov (United States)

Plošnik, Alja; Vračko, Marjan; Dolenc, Marija Sollner

2016-09-01

Knowing the mutagenic and carcinogenic properties of chemicals is very important for their hazard (and risk) assessment. One of the crucial events that trigger genotoxic and sometimes carcinogenic effects is the forming of adducts between chemical compounds and nucleic acids and histones. This review takes a look at the mechanisms related to specific functional groups (structural alerts or toxicophores) that may trigger genotoxic or epigenetic effects in the cells. We present up-to-date information about defined structural alerts with their mechanisms and the software based on this knowledge (QSAR models and classification schemes).

City air pollution of polycyclic aromatic hydrocarbons and other mutagens: occurrence, sources and health effects

DEFF Research Database (Denmark)

Nielsen, T.; Ejsing Jørgensen, Hans; Larsen, J.C.

1996-01-01

The presence of polycyclic aromatic hydrocarbons (PAH), mutagens and other air pollutants was investigated in a busy street in central Copenhagen and in a park area adjacent to the street. The winter concentration of benzo(a)pyrene was 4.4+/-1.2 ng/m(3) in the street air and 1.4+/-0.6 ng/m(3......) in the city park. The atmospheric concentrations of PAH decreased in the order of: street > city background air similar to suburbs > village > open land. The traffic contribution of PAH to street air was estimated to be 90% on working days and 60% during weekends and its contribution to city background air...... was estimated to be 40%. Four different approaches to evaluate the health effects are discussed. The direct effect of PAH air pollution, and other mutagens, is considered to be a maximum of five lung cancer cases each year out of one million people....

The influence of environmental exposure to complex mixtures including PAHs and lead on genotoxic effects in children living in Upper Silesia, Poland

DEFF Research Database (Denmark)

Mielzynska, Danuta; Siwinska, Ewa; Kapka, Lucyna

2006-01-01

of exposure were as follows: PbB 7.69 microg/dl, DNA adducts 9.59 adducts per 10(8) nt, 1-OHP 0.54 micromol/mol creatinine, and urinary mutagenicity presented as the number of revertants per mmol of creatinine: 485 for TA 98 and 1318 for YG1024. Mean value of MN was 4.44 per 1000 binucleated cells and SCE...

Phonic and induced level of mutations and mutagenicity in bioorganisms habitating in the environs of Ignalina APP

International Nuclear Information System (INIS)

Lekevichius, R.; Morkunas, V.; Knabikas, A.

1992-01-01

The investigation of the extracts from the water, mud and hydrobionts of the lake Drukshiai before the construction of the Ignalina atomic power plant (1982-1984) and after its construction enabled to detect the moment of the build-up of mutagens in the hydrobionts (in 1986), when the extracts began to induce spot mutations in Salmonella typhimurium and exchanges of sister chromatids in human leukocytes in vitro. The mutagenicity of rain water, sewerage water and water from the cooler of the atomic power plant to drosophila and Salmonella typhimurium has been detected. The increments of mutations in the populations of Larus ridibundus and Microtus arvalis inhabiting the surroundings of the atomic power plant has not been noticed. (author). 4 figs., 4 refs

Feature combination networks for the interpretation of statistical machine learning models: application to Ames mutagenicity.

Science.gov (United States)

Webb, Samuel J; Hanser, Thierry; Howlin, Brendan; Krause, Paul; Vessey, Jonathan D

2014-03-25

A new algorithm has been developed to enable the interpretation of black box models. The developed algorithm is agnostic to learning algorithm and open to all structural based descriptors such as fragments, keys and hashed fingerprints. The algorithm has provided meaningful interpretation of Ames mutagenicity predictions from both random forest and support vector machine models built on a variety of structural fingerprints.A fragmentation algorithm is utilised to investigate the model's behaviour on specific substructures present in the query. An output is formulated summarising causes of activation and deactivation. The algorithm is able to identify multiple causes of activation or deactivation in addition to identifying localised deactivations where the prediction for the query is active overall. No loss in performance is seen as there is no change in the prediction; the interpretation is produced directly on the model's behaviour for the specific query. Models have been built using multiple learning algorithms including support vector machine and random forest. The models were built on public Ames mutagenicity data and a variety of fingerprint descriptors were used. These models produced a good performance in both internal and external validation with accuracies around 82%. The models were used to evaluate the interpretation algorithm. Interpretation was revealed that links closely with understood mechanisms for Ames mutagenicity. This methodology allows for a greater utilisation of the predictions made by black box models and can expedite further study based on the output for a (quantitative) structure activity model. Additionally the algorithm could be utilised for chemical dataset investigation and knowledge extraction/human SAR development.

Photosynthetic and biochemical mechanisms of an EMS-mutagenized cowpea associated with its resistance to cowpea severe mosaic virus.

Science.gov (United States)

Souza, Pedro F N; Silva, Fredy D A; Carvalho, Fabricio E L; Silveira, Joaquim A G; Vasconcelos, Ilka M; Oliveira, Jose T A

2017-01-01

The seed treatment of a CPSMV-susceptible cowpea genotype with the mutagenic agent EMS generated mutagenized resistant plantlets that respond to the virus challenge by activating biochemical and physiological defense mechanisms. Cowpea is an important crop that makes major nutritional contributions particularly to the diet of the poor population worldwide. However, its production is low, because cowpea is naturally exposed to several abiotic and biotic stresses, including viral agents. Cowpea severe mosaic virus (CPSMV) drastically affects cowpea grain production. This study was conducted to compare photosynthetic and biochemical parameters of a CPSMV-susceptible cowpea (CE-31 genotype) and its derived ethyl methanesulfonate-mutagenized resistant plantlets, both challenged with CPSMV, to shed light on the mechanisms of virus resistance. CPSMV inoculation was done in the fully expanded secondary leaves, 15 days after planting. At 7 days post-inoculation, in vivo photosynthetic parameters were measured and leaves collected for biochemical analysis. CPSMV-inoculated mutagenized-resistant cowpea plantlets (MCPI) maintained higher photosynthesis index, chlorophyll, and carotenoid contents in relation to the susceptible (CE-31) CPSMV-inoculated cowpea (CPI). Visually, the MCPI leaves did not exhibit any viral symptoms neither the presence of the virus as examined by RT-PCR. In addition, MCPI showed higher SOD, GPOX, chitinase, and phenylalanine ammonia lyase activities, H 2 O 2 , phenolic contents, and cell wall lignifications, but lower CAT and APX activities in comparison to CPI. All together, these photosynthetic and biochemical changes might have contributed for the CPSMS resistance of MCPI. Contrarily, CPI plantlets showed CPSMV accumulation, severe disease symptoms, reduction in the photosynthesis-related parameters, chlorophyll, carotenoid, phenolic compound, and H 2 O 2 contents, in addition to increased β-1,3-glucanase, and catalase activities that might have

Characterization of Novel Sorghum brown midrib Mutants from an EMS-Mutagenized Population

OpenAIRE

Sattler, Scott E.; Saballos, Ana; Xin, Zhanguo; Funnell-Harris, Deanna L.; Vermerris, Wilfred; Pedersen, Jeffrey F.

2014-01-01

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously describe...

Mutagenic hazards of complex polycyclic aromatic hydrocarbon mixtures in contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Lemieux, C.L.; Lambert, A.B.; Lundstedt, S.; Tysklind, M.; White, P.A. [Health Canada, Ottawa, ON (Canada). Safe Environment Program

2008-04-15

The objective of the present study was to evaluate hazard/risk assessment methods for complex environmental mixtures that involve a targeted, priority chemical approach based on the cumulative hazard/risk of known mixture components or analyses of sufficiently similar mixtures. Ten polycyclic aromatic hydrocarbon (PAH)-contaminated soils were separated into nonpolar and semipolar fractions, and both fractions elicited positive responses on the Salmonella reverse mutation assay. Targeted and nontargeted methods of hazard prediction routinely overestimated mutagenic activities for the nonpolar soil fractions, suggesting nonadditive interactions of PAHs in complex mixtures. This suggests that current risk assessment methods for complex mixtures may provide conservative estimates regarding soils contaminated with priority PAHs alone. Significant underestimations of total risk, however, will be obtained if the soils also contain unidentified PAHs as well as polycyclic aromatic compounds and related compounds that contribute to the total mutagenic activity. Furthermore, estimates of excess lifetime cancer risk associated with the nondietary ingestion of the PAH-contaminated soils studied here indicate that a traditional risk assessment model based on identified priority PAHs and an assumption of additivity generally underestimates the risk associated with the nonpolar soil fractions (in comparison to bioassay-derived risk estimates). Additional cancer risk may be associated with the more polar compounds that also are found at these contaminated sites and that rarely are included in the standard risk assessment methodology.

Effect of mutagens, chemotherapeutic agents and defects in DNA repair genes on recombination in F' partial diploid Escherichia coli

International Nuclear Information System (INIS)

Norin, A.J.; Goldschmidt, E.P.

1979-01-01

The ability of mutagenic agents, nonmutagenic substances and defects in DNA repair to alter the genotype of F' partial diploid (F30) Escherichia coli was determined. The frequency of auxotrophic mutants and histidine requiring (His - ) haploid colonies was increased by mutagen treatment but Hfr colonies were not detected in F30 E. coli even with specific selection techniques. Genotype changes due to nonreciprocal recombination were determined by measuring the frequency of His - homogenotes, eg. F' hisC780, hisI + /hisC780, hisI + , arising from a His + heterogenote, F' hisC780 hisI + /hisC + , his1903. At least 75% of the recombinants were homozygous for histidine alleles which were present on the F' plasmid (exogenote) of the parental hetergenote rather than for histidine alleles on the chromosome. Mutagens, chemotherapeutic agents which block DNA synthesis and a defective DNA polymerase I gene, polA1, were found to increase the frequency of nonreciprocal recombination. A defect in the ability to excise thymine dimers, uvrC34, did not increase spontaneous nonreciprocal recombination. However, UV irradiation but not methyl methanesulfonate (MMS) induced greater recombination in this excision-repair defective mutant than in DNA-repair-proficient strains. (Auth.)

Exposure of health care workers and occupants to coughed airborne pathogens in a double-bed hospital patient room with overhead mixing ventilation

DEFF Research Database (Denmark)

Bolashikov, Zhecho D.; Melikov, Arsen K.; Brand, Marek

2012-01-01

The exposure of a doctor and a second patient was studied in a simulated two-bed hospital isolation room. The room was ventilated at three air change rates (3h-1, 6h-1, and 12h-1) by mixing air distribution keeping at 22C (71.6F). The effect of the distance between the doctor and the coughing...

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro extracts

Directory of Open Access Journals (Sweden)

Leonardo S. Vidal

2010-01-01

Full Text Available Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain. Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines.

Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution