• Journal of Plant Biology
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• 제35권3호
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• pp.253-257
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• 1992

Potyvirus group에 속하는 것으로 알려진 마늘 모자이크 바이러스 (GMV)가 식물에서 병을 유도하는 메카니즘을 이해하기 위하여, 마늘에 존재하는 GMV에 대한 cDNA clone인 clone 29-6을 분리하였다. Northern blot 분석에 의해 이 바이러스의 genome size는 약 9 kb이고, 또한 clone 29-6은 GLV genome과 유사성이 없었으며, 마늘잎으로부터 분리된 $poly(A)^{+}$ RNA와 강하게 hybridization되었다. 이러한 사실은 이 cDNA clone이 마늘에 감염하여 모자이크 병반을 유도하는 GMV에 대한 cDNA clone 중의 하나인 것으로 생각되었다. Clone 29-6을 probe으로 사용하여 마늘 바이러스의 cDNA 은행을 탐색하여 이와 중첩되는 clone을 선별하여 염기서열을 결정한 결과 이들의 염기서열이 중첩부위에서 서로 일치하지 않았는데 이는 마늘은 여러 형태의 GMV에 의해 감염되어 있음을 암시한다.

• Journal of Radiation Protection and Research
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• 제40권2호
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• pp.87-91
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• 2015

We have employed X-ray photoelectron spectroscopy (XPS) technique to examine the combined effects of low-energy electron (LEE) irradiation and $Fe^{3+}$ ion on DNA damage. pBR322 plasmid DNA extracted from E. coli ER2420 was used for preparing DNA-$Fe^{3+}$ sample. The C1s XPS spectra were scanned for LEE-irradiated and LEE-unirradiated samples and then curve-fitted. For the samples with LEE irradiation only or with Fe ion only, no significant changes from pure DNA samples were observed - a single effect of either $Fe^{3+}$ ion or LEE irradiation did not cause a significant damage. However, when these two components were combined, the DNA damage was increased quite significantly, compared to the sum of DNA damages caused by $Fe^{3+}$ ion and by LEE irradiation independently. This observation is consistent with our previous results [Radiat. Res. 177, 775 (2012)] which was done using gel-electrophoresis technique. Partial interpretation of the observed spectrum peaks was also attempted.

• Journal of Applied Biological Chemistry
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• 제53권4호
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• pp.202-206
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• 2010

The effects of aqueous extracts of red ginseng on the damage of DNA and erythrocyte by herbicides were evaluated using comet assay and hemolysis assay. Notably, the oxidative DNA damage and erytbrocyte hemolysis by 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were significantly suppressed by red ginseng treatment. Moreover, red ginseng could suppress significantly paraquat-induced oxidative DNA damage and hemolysis. These suppressive effects of red ginseng on the herbicide-induced damages might be due to the antioxidant components.

• Environmental Analysis Health and Toxicology
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• 제23권1호
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• pp.33-39
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• 2008

The genotoxicity of mercury compounds have been investigated with a variety of genetic endpoints in prokaryotic and eukaryotic cells. The mercury ions are positively charged and easily form complexes with DNA by binding with negatively charged centers to cause mutagenesis. Further, the mercury ions can react with sulfhydryl (-SH) groups of proteins associated with DNA replication and alter genetic information. Another mechanism by which mercury damages DNA molecule is via its probable involvement of reactive oxygen species (ROS) and induces DNA strand breaks. In order to investigate whether the ROS production was induced by mercury, we performed ROS assay. As the result, the ROS production was significantly increased when it grows dose-dependently and time-dependently. We compared mercury alone-treated group and mercury co-treated with Vitamin C or glutathione group. As the result, the ROS production induced by mercury was decreased by Vitamin C and glutathione. Co-treated with Vitamin C and glutathione group was the most effective to lowering ROS production induced by mercury.

• 한국자원식물학회지
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• 제22권6호
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• pp.489-497
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• 2009

In this study, we evaluated and compared the protective effects of two major constituents, baicalein and baicalin, against oxidative DNA and cell damages caused by hydroxyl radical. Antioxidant properties were evaluated using DPPH and hydroxyl radicals scavenging assays and $Fe^{2+}$ chelating assay. ${\varphi}X$ 174 RFI plasmid DNA and intracellular DNA migration assay were used to evaluate the protective effect against oxidative DNA damage. Also, MTT and lipid peroxidation assays were used to evaluate their protective effects against oxidative cell damage. Both baicalein and baicalin prevented intracellular DNA and cells from oxidative damage caused by hydroxyl radical via antioxidant activities. Baicalein demonstrated a stronger antioxidant activity in scavenging DPPH radicals and chelating $Fe^{2+}$ while baicalin scavenged hydroxyl radicals more efficiently. The differences in the level of baicalein and baicalin pose a different pathological pathway for each. The antioxidant activity of baicalin was due to its ability to scavenge hydroxyl radical whilst baicalein was a stronger $Fe^{2+}$ chelator. Further investigation to compare the molecular mechanisms of antitumor activities of baicalein and baicalin is vital to anticancer research.

• 대한의생명과학회지
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• 제15권1호
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• pp.1-8
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• 2009

Human genomic DNA is continuously attacked by oxygen radicals originated from cellular metabolic processes and numerous environmental carcinogens. 2-deoxyribonolactone (dL) is a major type of oxidized abasic (AP) lesion implicated in DNA strand scission, mutagenesis, and formation of covalent DNA-protein crosslink (DPC) with DNA polymerase (Pol) ${\beta}$. We show here that human DNA polymerase (Pol)${\iota}$ and mitochondrial $Pol{\gamma}$ give rise to stable DNA-protein crosslink (DPC) formation that is specifically mediated by dL lesion. $Pol{\gamma}$ mediates DPC formation at the incised dL residue by its 5'-deoxyribose-5-phosphate (dRP) lyase activity, while $Pol{\gamma}$ cross links with dL thorough its intrinsic dRP lyase and AP lyase activities. Reactivity in forming dL-mediated DPC was significantly higher with $Pol{\gamma}$ than with $Pol{\iota}$. DPC formation by $Pol{\gamma}$, however, can be reduced by an accessory factor of $Pol{\gamma}$ holoenzyme that may attenuate deleterious effects of crosslink adducts on mitochondrial DNA. Comparative kinetic analysis of DPC formation showed that the rate of DPC formation with either $Pol{\iota}$ or $Pol{\gamma}$ was lower than that with $Pol{\beta}$. These results revealed that the activity of catalytic lyase in DNA polymerases determine the efficiency of DPC formation with dL damages. Irreversible crosslink formation of such DNA polymerases by dL lesions may result in a prolonged strand scission and a suicide of DNA repair proteins, both of which could pose a threat to the genetic and structural integrity of DNA.

• Applied Biological Chemistry
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• 제48권2호
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• pp.155-160
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• 2005

본 연구에서는 매우 낮은 음의 산화환원전위를 나타내는 환원전리수가 paraquat에 의한 사람 임파구 DNA의 손상에 미치는 영향을 Comet assay를 사용하여 조사하였다. 환원전리수 처리에 의해서 paraquat에 의해 산화적으로 손상된 DNA가 회복되는 정도를 손상된 DNA로 인한 꼬리부분의 형광광도의 %비율로 나타내었다. Comet assay는 개별 세포의 DNA의 산화적 손상을 측정하는데 널리 사용되고 있다. 사람 임파구에 다양한 농도의 paraquat을 $37^{\circ}C$에서 30분간 처리한 후, 환원전리수를 첨가하여 30분간 반응시켰다. 그 결과 paraquat에 의한 임파구 DNA의 손상은 paraquart 농도증가에 의존적으로 증가하였다. 그러나 환원전리수를 처리한 결과 DNA의 산화적 손상이 paraquat 미처리 대조군 수준으로 거의 다 복구되었다.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.79-84
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• 2004

Three synthetic chemicals, benzoyl chloride, 2-propyn-l-ol, and 2-phenoxy ethanol were selected for genotoxicity testing, based on production quantity and available genotoxic data. In our previous report, benzoyl chloride induced chromosomal aberrations in Chinese hamster lung (CHL) fibroblast in vitro with and without metabolic activation, while 2-propyn-l-ol and 2-phenoxy ethanol induced only with metabolic activation. To compare the genotoxicity of chromosome aberration assay, the single cell gel electrophoresis (comet) assay subjected using CHL cells. As a result, statistically significant differences of tail moment values of benzoyl chloride, 2-propyn-1-ol, and 2-phenoxy ethanol were observed compared with control values on almost all concentrations with S9 or without S9 metabolic activation system. This results suggest that genotoxic results of the comet assay and the chromosome aberration assay show correlationship of genotoxicity in the CHL fibroblast. In summary, the positive result of chromosome aberration of benzoyl chloride, 2-propyn-l-ol, and 2-phenoxy ethanol was also induced DNA damages in comet assay with same cell line. Consequently, comet assay will be useful and more accurate tool to detect and to confirm the genotoxicity especially DNA damages in CHL fibroblast.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.151-151
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• 2001

According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process. We measured one kind of oxidative DNA damages, 8-hydroxydeoxyguanosine (8-OHdG) and its repair activities as an indicators of cellular oxidative stress in rat lungs by the repeated inhalation exposure to sodium chromate.(omitted)

• 대한본초학회지
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• 제21권4호
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• pp.77-84
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• 2006

Objectives : To evaluate the neuroprotective effects of modified Bo-Yang-Hwan-O-Tang (BHT), we investigated the neuronal death protection effects to oxidative damages in N2a neuroblastoma cells. Methods : To study the cytotoxic effect of BHT on N2a neuronal cells, the cell viability was determined by MTT assay. To investigate the neuronal death protection of BHT, N2a neuronal cells were induced oxidative damages by H2O2, and assayed the cell viability and DNA fragmentation. We also investigated DPPH free radical scavenging effects of BHT by tube test. Results : In MTT assay, $500{\mu}g/ml$ of BHT was not showed cytotoxic effect on N2a neuronal cells. BHT protected N2a neuronal cells from H2O2-induced cell death in a dose-dependent manner. BHT also protected N2a neuronal cells from H2O2-induced DNA fragmentation. BHT scavenged DPPH free radicals in a dose-dependent manner. Conclusion : These data suggest that BHT may have strong anti-oxidant effects through the free radical scavenging and neuroprotective effects in neuronal cells.