OBJECTIVETo study the genotoxicity induced by organic bentonite particles in vitro.

METHODSHuman B lymphoblast cells (HMy2.CIR) were exposed to organic bentonite particles at the doses of 0, 1.88, 3.75, 7.50 and 15.00 µg/ml for 24, 48 and 72 h, calcium sulfate (30 µg/ml) and SiO2 (30 and 240 µg/ml) served as negative and positive controls, respectively. The genotoxicity of organic bentonite particles and soluble fraction was detected using comet assay and Cytokinesis-block micronucleus (CBMN) assay.

RESULTSThe results of comet assay indicated that % tail DNA increased with the exposure doses and time in organic bentonite group, % tail DNA at the dose of 15.00 µg/ml for 24 h, 48 h and 72 h in organic bentonite group were 3.20 ± 0.19, 4.63 ± 0.88 and 9.49 ± 1.31 respectively which were significantly higher than those in calcium sulfate group (1.40 ± 0.11, 1.37 ± 0.22 and 0.90 ± 0.16) and those in 30 µg/ml SiO2 group (1.83 ± 0.21, 1.41 ± 0.27 and 2.48 ± 0.25) (P < 0.01). The results of CBMN assay showed that micronucleus frequencies (MNF) in organic bentonite group (except for 1.88 µg/ml for 24 h) were significantly higher than those in 30 µg/ml calcium sulfate group (MNF for 24, 48 and 72 h were 1.33‰ ± 0.58‰, 1.33‰ ± 1.15‰ and 1.33‰ ± 0.58‰) and those in 30 µg/ml SiO2 group (2.00‰ ± 0.00‰, 1.68‰ ± 0.58‰ and 2.33‰ ± 0.58‰) (P < 0.01). The results of two assays demonstrated that the soluble fraction of organic bentonite did not induce the genotoxicity.

CONCLUSIONThe organic bentonite dusts can induce the genotoxicity in vitro, which may be from the particle fraction.

Bentonite ; toxicity ; Cells, Cultured ; Comet Assay ; DNA Damage ; Humans ; Lymphocytes ; drug effects ; Micronucleus Tests ; Mutagenicity Tests ; Quartz ; toxicity

OBJECTIVES: We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. METHODS: Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration (0.2 microm pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. RESULTS: Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from 0.01 microg/mL to 10 microg/mL). In particular, MN induction was affected by cytoB. CONCLUSIONS: All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.
Animals ; Comet Assay ; Cricetinae ; Cricetulus ; Cytochalasin B ; DNA ; Female ; Filtration ; Liver ; Micronucleus Tests ; Mutagenicity Tests* ; Nanoparticles* ; Ovary ; Rats ; Salmonella typhimurium ; Silver* ; Sonication

OBJECTIVETo determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC).

METHODSThe synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were studied using single cell gel electrophoresis (SCGE) assay (comet assay) and cytokinesis-blocked micronucleus (CBMN) test in vitro. The whole blood cells from a male donor and a female donor were either only exposed to 2450-MHz microwaves (5.0 mW/cm2) for 2 h or only exposed to MMC (0.0125 microgram/mL, 0.025 microgram/mL and 0.1 microgram/mL) for 24 h; and the samples were exposed to MMC for 24 h after exposure to MW for 2 h.

RESULTSIn the comet assay, the comet lengths (29.1 microns and 25.9 microns) of MW were not significantly longer than those (26.3 microns and 24.1 microns) of controls (P > 0.05). The comet lengths (57.4 microns, 68.9 microns, 91.4 microns, 150.6 microns, 71.7 microns, 100.1 microns, 145.1 microns) of 4 MMC groups were significantly longer than those of controls (P < 0.01). The comet lengths (59.1 microns, 92.3 microns, 124.5 microns, 182.7 microns and 57.4 microns, 85.5 microns, 137.5 microns, 178.3 microns) of 4 MW plus MMC groups were significantly longer than those of controls too (P < 0.01). The comet lengths of MW plus MMC groups were significantly longer than those of the corresponding MMC doses (P < 0.05 or P < 0.01) when the doses of MMC were > or = 0.025 microgram/mL. In the CBMN, the micronucleated cell (MNC) rates of MW were 5@1000 and 6@1000, which showed no difference compared with those (4@1000 and 4@1000) of controls (P > 0.05). The MNC rates of 4 MMC groups were 8@1000, 9@1000, 14@1000, 23@1000 and 8@1000, 8@1000, 16@1000, 30@1000 respectively. When the doses of MMC were > or = 0.05 microgram/mL, MNC rates of MMC were higher than those of controls (P < 0.05). MNC rates of 4 MW plus MMC groups were 12@1000, 13@1000, 20@1000, 32@1000 and 8@1000, 9@1000, 23@1000, 40@1000. When the doses of MMC were > or = 0.05 microgram/mL, MNC rates of MW plus MMC groups were much higher than those of controls (P < 0.01). MNC rates of 4 MW plus MMC groups were not significantly higher than those of the corresponding MMC doses.

CONCLUSIONThe low-intensity 2450-MHz microwave radiation can not induce DNA and chromosome damage, but can increase DNA damage effect induced by MMC in comet assay.

Antibiotics, Antineoplastic ; adverse effects ; Cell Culture Techniques ; Chromosome Aberrations ; chemically induced ; Comet Assay ; DNA Damage ; Female ; Humans ; Lymphocytes ; Male ; Micronucleus Tests ; Microwaves ; adverse effects ; Mitomycin ; adverse effects ; Mutagenicity Tests

Chemical mutagenicity is a major hazard that is important to workers' health. Despite the use of large amounts of allyl chloride, the available mutagenicity data for this chemical remains controversial. To clarify the mutagenicity of allyl chloride and because a micronucleus (MN) test had not yet been conducted, we screened for MN induction by using male ICR mice bone marrow cells. The test results indicated that this chemical is not mutagenic under the test conditions. In this paper, the regulatory test battery and several assay combinations used to determine the genotoxic potential of chemicals in the workplace have been described. Further application of these assays may prove useful in future development strategies of hazard evaluations of industrial chemicals. This study also should help to improve the testing of this chemical by commonly used mutagenicity testing methods and investigations on the underlying mechanisms and could be applicable for workers' health.
Animals ; Bone Marrow Cells ; Classification* ; Humans ; Male ; Mice ; Mice, Inbred ICR ; Micronucleus Tests* ; Mutagenicity Tests* ; Occupational Diseases

Alkanes ; toxicity ; Animals ; Chromosome Aberrations ; Mice ; Mice, Inbred ICR ; Micronucleus Tests ; Mutagenicity Tests ; Mutagens ; Rats ; Rats, Sprague-Dawley ; Teratogens

OBJECTIVETo study the genotoxicity of components of diesel engine exhausts with ethanol-diesel blending fuel. To provide scientific arguments to find more economical and less polluted fuels.

METHODSAmes test, comet assay and GC-MS technique were used to test the genotoxicity and 16 kinds of PAHs on diesel engine exhausts with different proportions of ethanol (E0, E5, E10, E20).

RESULTSBoth Ames test and comet assay were positive. It shows that diesel engine exhausts can lead to mutation and DNA damage, especially in pure diesel oil. But the content of 16 kinds of PAHs and DNA damage level decreased in exhausts of E5. With the increase of ethanol proportion in diesel oil, the content of 16 kinds of PAHs and DNA damage level increased.

CONCLUSIONCompared with pure diesel oil and high proportion of ethanol fuel, E5 can reduce the genotoxicity and the brake specific exhausts of PAHs.

Air Pollutants ; toxicity ; Air Pollution ; Carbon Monoxide ; Comet Assay ; DNA Damage ; Ethanol ; toxicity ; Gasoline ; toxicity ; Mutagenicity Tests ; Particulate Matter ; Vehicle Emissions ; toxicity

Electromagnetic Fields ; adverse effects ; Humans ; Mutagenicity Tests

The overseas and domestic application status and research progress of genotoxicity evaluation of medical devices is briefly introduced. The trend of future development is analyzed.
Equipment and Supplies ; adverse effects ; Mutagenicity Tests

OBJECTIVEThe micronucleus test was applied to evaluate the genotoxicity of a new nanocomplex HA-PA66 root filling material in vitro.

METHODSThe dulbecco's modified eagle media(DMEM) extracts of the powder part and the mixture of the new nanomaterial were prepared separately. The V79 cell was used as the test cell and the mitomycin C(MMC) as the positive control. The MTT assay was employed in our study to evaluate the cytotoxic effect while the number of micronucleus was used as the criteria for the detection of genotoxocity.

RESULTSThe MTT values in test groups and negative group were not significantly different at different times (P > 0.05). The number of micronucleus in test groups (powder group: 6.1 +/- 1.1/1,000; complex group: 5.7 +/- 0.6/1,000) was similar to the negative control(5.3 +/- 0.8/1,000, P > 0.05), while they were significantly different to the positive control(123.9 +/- 8/1,000, P < 0.05).

CONCLUSIONThe new nanocomplex HA-PA66 root filling material showed no detectable cytotoxic and genotoxic effects in this study and was proved to be biocompatible.

Animals ; Biocompatible Materials ; toxicity ; Cricetinae ; Cricetulus ; Durapatite ; toxicity ; Micronucleus Tests ; methods ; Mutagenicity Tests ; methods ; Nanotechnology ; Nylons ; toxicity ; Root Canal Filling Materials ; toxicity

This study deals with the serious pollution of Seoul's ambient air and extends a warning regarding its adverse effects on human health. The collected dust samples exceeded the legal standard (15O microgram/m3 of total suspended particulates) of ambient air quality. Fine particles, with an aerodynamic diameter of less than 2.5 micrometer comprised on the average 75.4 percent of the total suspended particulates (TSP). The amount of ether extractable organic matter (EEOM) of the fine particles was found to range from 3.6 to 7.1 percent. Neutral, acidic and basic organics were fractionated. In the neutral fraction, aliphatic compounds (ALP), polyaromatic hydrocarbons0 (PAH), and polar neutral organic compounds (POCN) comprised 23.1, 37.8 and 39.1 percent, respectively. Mutagenic activities of the organic fractions were determined by Ames bioassay. PAH showed the most mutagenicity using Salmonella typhimurium TA98 strain and TA98NR(nitro-reductase activity deficient stain) in the presence of S-9 fractions.
Dust/analysis* ; Human ; Korea ; Mutagenicity Tests* ; Polycyclic Hydrocarbons/analysis*