• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.90-97
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• 2007

8-Hydroxyquinoline is used as antibacterial agent and antioxidant based on its function inducing the chelation of ferrous ion present in host resulting in production of chelated complex. This complex being transported to cell membrane of bacteria and fungi exerts antibacterial and antifungal action. In this study, we have carried out in vitro genetic toxicity tests and microarray analysis to understand the underlying mechanisms and the mode of action of toxicity of 8-hydroxyquinoline. TA1535 and TA98 cells were treated with 8-hydroxyquinoline to test its toxicity by basic genetic toxicity test, Ames and two new in vitro micronucleus and COMET assays were applied using CHO cells and L5178Y cells, respectively. In addition, microarray analysis of differentially expressed genes in L5178Y cells in response to 8-hydroxyquinoline were analyzed using Affymatrix genechip. The result of Ames test was that 8-hydroxyquinoline treatment increased the mutations in base substitution strain TA1535 and likewise, 8-hydroxyquinoline also increased mutations in frame shift TA98. 8-Hydroxyquinoline increased micronuclei in CHO cells and DNA damage in L5178Y. 8-Hdroxyquinoline resulted in positive response in all three tests showing its ability to induce not only mutation but also DNA damage. 783 Genes were initially selected as differentially expressed genes in response to 8-hydroxyquinoline by microarray analysis and 34 genes among them were over 4 times of log fold changed. These 34 genes could be candidate biomarkers of genetic toxic action of 8-hydroxyquinoline related to induction of mutation and/or induction of micronuclei and DNA damage. Further confirmation of these candidate markers related to their biological function will be useful to understand the detailed mode of action of 8-hydroxyquinoline.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.243-249
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• 2004

The cytokinesis-block micronucleus (CBMN) assay in combination with FISH technique using chromosome-specific centromeric probes for chromosome 1 and 4 was performed in mitogen stimulated human lymphocytes which were exposed to x-radiation to identify different sensitivity of chromosomes to the induction of micronuclei(MN) and aneuploidy by radiation. The frequencies of micronucleated cytokinesis-blocked(MNCB) cells and MN in binucleated lymphocytes(BN) increased with the increase in radiation dose. A significant induction of aneuploidy of chromosome 1 and 4 were found. The frequency of aneuploidy of chromosome 1 and 4 in the control were 9 per 2,000 BN cells and this increased to 47 and 71 following irradiation at a dose of 1 and 2 Gy, respectively. The induction of aneuploidy of chromosome 1 was higher than that of chromosome 4. The frequency of aneuploid BN cells with MN exhibiting positive centromere signal for either chromosome 1 and/or 4 increased in a dose dependent manner, and that for chromosome 1 is higher than that for chromosome 4. Among the total induced MN in irradiated lymphocytes, smaller proportion of MN exhibit centromeric signal of chromosome indicating that radiation-induced MN are mainly originated from chromosomal breakage rather than chromosomal non-disjunction. These results suggest that x-radiation can induce aneuploidy and supports the finding that chromosome vary in their sensitivity to aneuploidy induction by x-irradiation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.211-216
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• 2016

Micronucleus test is genotoxicity assay for detection of micronuclei in the cytoplasm of interphase cells. The reduction and replacement of in vivo toxicity testing on animals require the development of in vitro models to predict the genotoxicity or other tests for cosmetic products. In this study, we evaluated a genotoxicity assay for topically applied chemicals using a three-dimensional human reconstructed skin model, KeraSkin$^{TM}$. Two genotoxins, mitomycin C (MMC) and methyl methanesulfonate (MMS), induced significant dose-related increases in cytotoxicity and micronuclei induction in the skin model. In contrast, two non-genotoxins, 4-nitrophenol (4-NP) and trichloroethylene (TCE), induced cytotoxicity but not micronucleus formation. In conclusion, micronucleus test using human skin model may be useful for predicting in vitro genotoxic potentials of cosmetic products.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.375-382
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• 2015

We discovered three soil ciliates of the class Colpodea-Colpoda henneguyi Fabre-Domergue, 1889; C. lucida Greeff, 1888; and Bursaria truncatella $M{\ddot{u}}ller$, 1773 from Obong-ri, Ayajin-ri and Elwang-ri (Korea), respectively. Colpoda henneguyi had the following features: often wider preorally than postorally, size in vivo $60-80{\mu}m{\times}50-70{\mu}m$; extrusomes indistinct in vivo, cylindroid approximately $1{\mu}m$ long; notches caused by deep diagonal groove; yellowish globules on the cortex of the cell; 10-12 postoral kineties; silverline system aspera-type. Colpoda lucida exhibited the following features: broadly reniform, size in vivo $70-90{\mu}m{\times}50-70{\mu}m$; conspicuous extrusomes, $3.5-5{\mu}m$ long in vivo, cylindroid to fusiform; 13-16 postoral kineties; silverline system cucullus-type. Bursaria truncatella had the following features: bursiform, size in vivo $300-470{\mu}m{\times}120-260{\mu}m$; macronucleus coiled with highly variable shapes, $600-1100{\mu}m{\times}30-40{\mu}m$ long in vivo; micronuclei 16-25 in number, approximately $4{\mu}m$ in diameter; extrusomes cylindroid, $3-4{\mu}m$ long in vivo. This is the first report of colpodean ciliates from Korea, and we describe these species based on observations of live and impregnated (protargol and silver nitrate impregnation) specimens.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5333-5338
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• 2012

Vitamin B6 functions as a coenzyme in >140 enzymatic reactions involved in the metabolism of amino acids, carbohydrates, neurotransmitters, and lipids. It comprises a group of three related 3-hydroxy-2-methyl-pyrimidine derivatives: pyridoxine (PN), pyridoxal (PL), pyridoxamine (PM) and their phosphorylated derivatives [pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP)], In the folate metabolism pathway, PLP is a cofactor for the mitochondrial and cytoplasmic isozymes of serine hydroxymethyltransferase (SHMT2 and SHMT1), the P-protein of the glycine cleavage system, cystathionine ${\beta}$-synthase (CBS) and ${\gamma}$-cystathionase, and betaine hydroxymethyltransferase (BHMT), all of which contribute to homocysteine metabolism either through folate-mediated one-carbon metabolism or the transsulfuration pathway. Folate cofactors carry and chemically activate single carbons for the synthesis of purines, thymidylate and methionine. So the evidence indicates that vitamin B6 plays an important role in maintenance of the genome, epigenetic stability and homocysteine metabolism. This article focuses on studies of strand breaks, micronuclei, or chromosomal aberrations regarding protective effects of vitamin B6, and probes whether it is folate-mediated one-carbon metabolism or the transsulfuration pathway for vitamin B6 which plays critical roles in prevention of cancer and cardiovascular disease.

• Environmental Mutagens and Carcinogens
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• v.24 no.2
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• pp.91-98
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• 2004

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) is a powerful carcinogen in several species, limited model system exist to study carcinogenicity of this compound at cellular level. To enhance our under-standing of carcinogenicity of TCDD at cellular level, we investigated micronucleus (MN) frequency as a index of genetic toxicity and whether TCDD can transform the human cells in culture. Normal human cell lines, skin keratinocyte HaCaT, Chang liver and breast MCF10A cells were used. TCDD did not affect the cell viability of the Chang liver, HaCaT and MCF10A cells. The frequency of micronucleus was increased after treatment of TCDD for 24hr in Chang liver and HaCaT cells, but not changed in MCF10A cells. And we observed putative transformed cells in Chang liver cells exposed to 1 $\mu$M TCDD for 2 weeks. The putative transformed cells were also observed in HaCaT cells with subsequent exposure to TCDD (0.1, 1, 10, 100 nM) for 2 weeks after initial exposure to MNNG, but not observed in MCF10A cells. Collectively, these results indicate that the ability of TCDD to induce micronuclei may be involved in cellular transformation of Chang liver and HaCaT cells. Our putative TCDD-transformed cells of Chang liver and HaCaT are expected to provide a clue to the elucidation of TCDD-induced transformation pathway.

• Animal Systematics, Evolution and Diversity
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• v.31 no.3
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• pp.182-190
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• 2015

Two heterotrichid ciliates, Climacostomum virens (Ehrenberg, 1838) Stein, 1859 from brackish water and freshwater, and Fabrea salina Henneguy, 1890 from a solar saltern, were collected in Korea. They are novelly investigated in Korea by means of live observation, protargol staining and nuclear small subunit (SSU) rRNA gene sequencing. Climacostomum virens is characterized by pouch-like body shape, body length of $200-370{\mu}m$ in vivo, conspicuous cytopharyngeal tube, macronuclei ribbon-like shape, and one to four in number, with or without symbiont algae in cytoplasm, 34-66 somatic kineties, 67-113 adoral zone of membranelles, 8-42 peristomial kineties, 24-37 apical membranelles. SSU rDNA sequence size is 1,591 bp and GC contents 48.52%. Fabrea salina is also characterized by scoop-like body shape with proboscis, body length of $190-240{\mu}m$ in vivo, one to two rod-shaped macronuclei, oval micronuclei, grayish green cortical granules, 104-186 somatic kineties, 4-8 preoral kineties, 7-19 peristomial kineties and fragmented paroral membrane. SSU rDNA sequence size is 1,598 bp and GC contents 47.50%.

• The Korean Journal of Community Living Science
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• v.28 no.1
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• pp.131-141
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• 2017

This study was carried out to perform genotoxicological safety evaluation of crude antifungal compounds produced by Bacillus subtilis SN7 (B. subtilis SN7) isolated from meju. Bacterial reverse mutation assay with Salmonella typhimurium TA98, TA100, TA1535, and TA1537 or Escherichia coli WP2uvrA in the presence and absence of the S9 metabolic activation system was carried out, and the crude antifungal compounds produced by B. subtilis SN7 showed no significant increase in the number of revertant colonies. In the chromosomal aberration tests using Chinese hamster lung (CHL) cells, sample treatment groups showed no increase in the frequency of chromosome aberrations compared to the negative control group. Furthermore, in the micronucleus formation test, the crude antifungal compounds showed no significance increase in the frequency of polychromatic erythrocytes with micronuclei. These results suggest that the crude antifungal compounds produced by B. subtilis SN7 isolated from meju showed no harmful genotoxic effects.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.29-35
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• 2012

Two Spirostomum species collected from freshwater in Korea were identified as S. caudatum (Muller, 1786) and S. teres (Claparede and Lachmann, 1858). They are recorded for the first time in Korea. The description was based on the observation of living specimens and protargol impregnated specimens. Diagnostics of these species are as follows. Spirostomum caudatum: body size $400-450{\times}20-30\;{\mu}m$ in vivo, shaped long and slender with a tapered posterior part, highly contractile; macronucleus ellipsoid; adoral zone of membranelles occupied 30% of body length; somatic kineties 14-22 in number. Spirostomum teres: body size $240-460{\times}25-40\;{\mu}m$ in vivo, shaped long and slender with a flattened posterior end, highly contractile; cortical granules arranged in 2-3 rows; adoral zone of membranelles occupied 50% of body length; somatic kineties 20-30 in number; macronucleus ellipsoid; micronuclei 2-3 in number. Spirostomum caudatum and S. teres are the most similar congeners, but they are different in the posterior part of body (tail-like posterior part vs. flattened posterior end), length of adoral zone of membranelles in body length (1/3 vs. 1/2), and the number of somatic kineties (14-22 vs. 20-30). These populations match with European populations in morphological characters.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.150-150
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• 2001

To investigate the genotoxic effect of 1, 1-dichloro-1-fluoroethane, which was widely used as a cleaning solvent at the electronic part industry, the micronucleus frequencies were recorded by examining polychromatic erythrocytes in bone marrows of the rodents exposed to it with different routes.(omitted)