• Toxicological Research
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• v.24 no.2
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• pp.151-159
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• 2008

Rhus verniciflua Stokes(RVS), one of traditional medicinal plants in Asia, was found to have pharmacological activities such as antioxidative and antiapoptotic effects, raising the possibility for the development of a novel class of anti-cancer drugs. Thus, potential genotoxic effects of RVS in three short-term mutagenicity assays were investigated, which included the Ames assay, in vitro Chromosomal aberration test, and the in vivo Micronucleus assay. In Ames test, the addition of RVS water extracts at doses from 313 up to 5000 mg/plate induced an increase more than 2-fold over vehicle control in the number of revertant colonies in TA98 and TA1537 strains for detecting the frame-shift mutagens. The similar increase in reversion frequency was observed after the addition of RVS ethanol extracts. To assess clastogenic effect, in vitro chromosomal aberration test and in vivo micronucleus assay were performed using Chinese hamster lung cells and male ICR mice, respectively. Both water and ethanol extracts from RVS induced significant increases in the number of metaphases with structural aberrations mostly at concentrations showing the cell survival less than 60% as assessed by in vitro CA test. Also, there was a weak but statistically significant increase in number of micronucleated polychromatic erythrocytes(MNPCEs) in mice treated with water extract at 2000 mg/kg while ethanol extracts of RVS at doses of up to 2000 mg/kg did not induce any statistically significant changes in the incidence of MNPCEs. Therefore, our results lead to conclusion that RVS acts as a genotoxic material based on the available in vitro and in vivo results.

• Toxicological Research
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• v.30 no.3
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• pp.211-220
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• 2014

Resveratrol has received considerable attention as a polyphenol with various biological effects such as anti-inflammatory, anti-oxidant, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. As part of the overall safety assessment of HS-1793, a novel resveratrol analogue free from the restriction of metabolic instability and the high dose requirement of resveratrol, we assessed genotoxicity in three in vitro assays: a bacterial mutation assay, a comet assay, and a chromosomal aberration assay. In the bacterial reverse mutation assay, HS-1793 did not increase revertant colony numbers in S. typhimurium strains (TA98, TA100, TA1535 and TA1537) or an E. coli strain (WP2 uvrA) regardless of metabolic activation. HS-1793 showed no evidence of genotoxic activity such as DNA damage on L5178Y $Tk^{+/-}$ mouse lymphoma cells with or without the S9 mix in the in vitro comet assay. No statistically significant differences in the incidence of chromosomal aberrations following HS-1793 treatment was observed on Chinese hamster lung cells exposed with or without the S9 mix. These results provide additional evidence that HS-1793 is non-genotoxic at the dose tested in three standard tests and further supports the generally recognized as safe determination of HS-1793 during early drug development.

• Korean Journal of Microbiology
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• v.17 no.3
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• pp.137-151
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• 1979

Germinating conidia of Aspergillus nidulans diploid heterozygous for color and other genetic markers were used to direct and distinguish genetic events such as mutation, mitotic crossingover and nondisjunction in a single test after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NG), mitomycin C(MC), and chloral hydrate(CH). The following results were obtained : 1. NG reduced the survival of conidia and increased the frequencies of miototic segregants about sevenfoli over the control ; among the mitotic segregants the predominant genetic event was mitotic crossingover. NG also produced many abnormal colonies, which appeared to be of the types caused by induced semidominant lethals or chromosomal aberrations, and the aneuploid types found spontaneously. 2. After treatment with MC the survival of conidia was reduced but few abnormal colonies were produced. The frequencies of miotic segregants were increased about threefold over the control ; in the mitotic segeregants the induced genetic event was mitotic crossingover. 3. CH gave no apparent effect on the survival of conidia and the frequencies of mitotic segregants. However, CH generated abnormal colonies, very greatly, which turned out to be of the aneuploid types. This result suggests that CH interferes with the normal distribution of chromosomes in mitosis.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.897-898
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• 2008

Array comparative genomic hybridization (aCGH) has been used to detect chromosomal regions of amplifications or deletions, which allows identification of new cancer related genes. As aCGH, a large-scale spatial data, contains significant amount of noises in its raw data, it has been an important research issue to segment genomic DNA regions to detect its true underlying copy number aberrations (CNAs). In this study, we focus on applying a segmentation method to multiple data sets. We compare two different threshold values for analyzing aCGH data with CBS method [1]. The proposed threshold values are p-value or $Q{\pm}1.5IQR$ and $Q{\pm}1.5IQR$.

• Parasites, Hosts and Diseases
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• v.41 no.1
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• pp.41-45
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• 2003

Effects of gamma irradiation on the worm survival and chromosomal aberration of Clonorchis sinensis were studied. The metacercariae irradiated with various amounts of gamma radiation (ranging from 5 Gy to 50 Gy) were fed to rats, and the effects were compared with those of non-irradiated controls. Recovery rates of adult worms in irradiated groups were reduced gradually as increasing of the irradiation doses. No worm was recovered from rats which were fed with 50 Gy irradiated metacercariae. The chromosome number was 2n = 56 in all worms from all experimental groups. However, the groups irradiated with 20 Gy, 25 Gy or 30 Gy showed variations in the chromosome number, depending on different cells in the same individual. Radiation doses used in this study did not appear to induce chromosome aberrations, however, irradiation with 30 Gy showed slightly reduced chromosome size.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.245-250
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• 1984

Reciprocal exchanges of DNA in sister chromatids (SCEs) are induced by various carcinogens and mutagens, although the quantitative relationship between the number of mutations and SCEs induced varies among chemicals. Nevertheless, the analysis of SCEs production by various agents often proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity. Mercury, even if which has no evidences for mutagenicity and carcinogenicity, is reported to exert some cytotoxic effects, such as chromosomal aberrations or bad influences to ovulation and reproduction in experimental animals, etc.. In this study, tests for sister chromatid exchanges have been carried out on normal human lymphocytes in whole blood culture to add mercury chloride ($HgCl_2$) or methylmercury chloride ($CH_3\;HgCl$) for 72 hr. The results indicate the dose-dependent relationship between the frequencies of SCEs and the concentrations of $HgCl_2,\;CH_{3}HgCl$ and 5-bromo-2'-deoxyuridine (BrdU). Lymphocyte proliferation has depressed in the higher concentration of mercury.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.125-126
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• 2006

NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.124-124
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• 2002

• Journal of Plant Biology
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• v.33 no.3
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• pp.189-196
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• 1990

Suspension cell lines have been newly established from the calli derived from the immuature embryo culture of hexapolid (Triticum aestivum var. sicco), tetrapolid (T. durum) and diploid (T. tauchii or Aegilops squarrosa) wheat species. The chromosomal variation in suspension cultured cell lines was examined and old cell line, C82d, established from T. aestivum var. copain was also used. New method using 1-bromonaphthalene for metaphase rapping of suspension cells was developed. Variation in chromosome number was observed among all the suspension lines. Cells with doubled chromosome number and deleted chromosome were also observed. Extensive structural changes in chromosome were found in C82d line. Chromosome aberrations showed loss of chromosome arms and chromosome segment. The mean chromosome number in suspension cells of T. aestivum var. sicco was 40, in C82d line 33, in T. durum 28 and in T. tauchii 14. The stability of chromosome in suspension cells of diploid and tetrapolid wheats was higher than that of hexaploid wheat.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.233-240
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• 1993

Chromosomal aberration analysis, as a basis for biological radiation dosimetry, was performed for radiation dose ranges below 150 cGy. The yield, ratio of lymphocytes with dicentric and/or ring chromosomes, was 0, 0, 0.4, 0.5, 0.6, 0.8, 1.8, 5.5, 8.0, and $18.5\%$ for 0,5, 10, 15, 20, 25, 50, 75, 100 and 150 cGy, respectively. The Qdr, ratio of dicentric and ring chromosomes in total lymphocytes, was 0, 0, 0.004, 0.005, 0.006, 0.009, 0.018, 0.055, 0.084 and 0.207, respectively. The Qdr, ratio of dicentric and ring chromosomes in lymphocytes with aberration, was 1.0 for the radiation doses up to 75 cGy and 1.05 and 1.11 for 100 and 150 cGy, respectively. From the results, it seems possible to estimate radiation dose from Ydr when the exposure is 25 cGy or more. All the 5 radiation workers studied, with exposure much less than 1 mSv per month, had chromosomal aberrations. And acentric fragment pairs, in addition to dicentric and ring chromosomes, showed good dose response relationship and so may be useful for biological dosimetry for low dose radiation.