• BMB Reports
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• v.32 no.2
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• pp.161-167
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• 1999

The role of oxidative stress in the initiation and the complication of diabetes was examined by monitoring blood glucose increase and oxidative DNA damage in rats treated with alloxan or streptozotocin (STZ). Oxidative DNA damage was assessed by quantitating 8-oxo-2'-deoxyguanosine ($oxo^8dG)$ excreted in urine and the $oxo^8dG$ accumulated in pancreas DNA. Both alloxan and STZ treatments resulted in an abrupt increase in blood glucose and significant increases in urinary and pancreatic $oxo^8dG$. Pretreatment of buthionine sulfoximine (BSO), a glutathione-depleting agent, slightly potentiated the increase of blood glucose and urinary $oxo^8dG$ in the alloxan- and STZ-treated rats. Furthermore, the BSO pretreatment caused significant amplification of pancreatic $oxo^8dG$ increase in the rats. On the other hand, pretreatment with 1,10- phenanthroline (o-phen), a chelator of divalent cations, showed different results between alloxan- and STZ-treated rats. The o-phen pretreatment completely blocked diabetes and the increase of $oxo^8dG$ by alloxan treatment, while it potentiated the increase of blood glucose and $oxo^8dG$ by STZ treatment. The results demonstrate that the causative effect of alloxan on diabetes may be the generation of reactive oxygen species through a Fenton type reaction, but that of STZ may not.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.208-217
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• 2022

We wanted to develop a real-time PCR assay capable of detecting Liobagrus obesus in environmental DNA (eDNA) extracted from freshwater samples using a pair of species-specific primers and probe for the endangered fish, L. obesus. The species-specific primers and probe were designed in consideration of single nucleotide polymorphisms between 65 species of freshwater fish living in the Republic of Korea within the cytochrome b (cytb) gene of mitochondrial DNA. The species-specific primers and probe, in the real-time PCR assay, showed high specificity as only the L. obesus genomic DNA (gDNA) was found to be positive in the specificity verification using 65 species gDNA of freshwater fish in the Republic of Korea. In addition, in the detection limit analysis using the serial dilution concentrations of L. obesus gDNA, it was found that it was possible to detect up to 0.2 pg, showing high sensitivity. Afterwards, using the species-specific primers and probe, real-time PCR assay was performed on freshwater samples obtained from 8 stations in the mid-upper basin of Geum River. As a result, the cytb gene of L. obesus was detected in total 5 stations including all 3 stations where this species was collected at the time of field survey. Therefore, the species-specific primers and probe developed in present study, and the real-time PCR assay using them, can accurately detect the cytb gene of L. obesus from eDNA samples, which can be utilized to monitor the existing habitats of this species and to discover potential new habitats.

• 대한약리학회:학술대회논문집
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• 2006.11a
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• pp.69.2-69.2
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• 2006

• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.355-364
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• 1969

Cross-hybridizations between DNA of two pseudomonads and a xanthomonad suggested that the three DNA types had a considerable section in common. The existence of this common part was proved by hybridization of preselected DNA, i.e. DNA resulting from a previous hybridization between any one set of two DNA types, with the third type. It was thus shown that about 50% of the DNA of the three organisms was similar. This common part was isolated in pure state and its % (G+C) was found to be indentical to the overall base composition of the native DNA. The evolutionary drift in % (G+C) could thus not be detected. The total molecular weight of the chromosornal DNA/bacterial nucleoid was determined to be 2.4 ${\times} 10^9$daltons. It can therefore be estimated that the common putida-fluorescenspelargonii DNA part consists of some 2,000 cistrons. P. putida and P. fluorescens share an additional 1,300 cistrons, and all xanthomonads share at least an additional 1,000 cistrons.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.99-105
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• 2005

Perchloroethylene (tetrachloroethylene, PCE), a dry cleaning and degreasing solvent, can enter ground-water through accidental leak or spills. PCE can be degraded to trichloroethylene (TCE), 1, 1-dichloroethylene (DCE) and vinyl chloride (VC) as potential bio-product. These compounds have been reported that they can cause clinical diseases and cytotoxicity. However, only a little genotoxic information of these compounds has been known. In this study, we investigated DNA single strand breaks of PCE, TCE, DCE and VC by single cell gel electrophoresis assay, (comet assay) which is a sensitive, reliable and rapid method for DNA single strand breaks with mouse lymphoma L5178Y cells. From these results, $37.5\;{\mu}g/ml$ of PCE, $189\;{\mu}g/ml$ of TCE and $56.4\;{\mu}g/ml$ of DCE were revealed significant DNA damages in the absence of S-9 metabolic activation system meaning direct-acting mutagen. And in the presence of S-9 metabolic activation system, $41.5\;{\mu}g/ml$ of PCE, $328.7\;{\mu}g/ml$ of TCE and $949\;{\mu}g/ml$ of DCE were induced significant DNA damage. In the case of VC, it was revealed a significant DNA damage in the presence of S-9 metabolic activation system. Therefore, we suggest that chloroethylene compounds (PCE, TCE, DCE and VC) may be induced the DNA damage in a mammalian cell.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.125-132
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• 2003

The present study was attempted to investigate and compare the antioxidant potency of several well-know flavonoids, antioxidant vitamin and commercially available popular beverages. The antioxidant potency was assessed by the effect on reducing oxidative DNA damage of human lymphocytes. Cellular oxidative DNA damage was measured by SCGE (single-cell gel electrophoresis), also known as comet assay. Lymphocytes were pre-treated for 30 minutes with wide ranges of doses of apigenin, kaempferol, luteolin, myricetin, rutin, quercetin, $\alpha$-tocopherol (10,25,50,100,200,500,1000 $\mu$M) ,green tea extract or grape juice (10,50,100,250,500,1000 $\mu$g/mL) followed by a $H_2O$$_2$(100 $\mu$M) treatment for 5 min as an oxidative stimulus. The physiological function of each antioxidant substance on oxidative DNA damage was analyzed as tail moment (tail length $\times$ percentage migrated DNA in tail) and expressed as relative DNA damage score after adjusting by the level of control treatment. Cells treated with $H_2O$$_2$alone (positive control) had an extensive DNA damage compared with cells treated with phosphate buffered saline (PBS, negative control) or pre-treated with all the tested samples. Of all the six flavonoids, quercetin was the most potent antioxidant showing the lowest $ED_{50}$/ of 8.5 $\mu$g/mL (concentration to produce 50% protection of relative DNA damage). The antoxidant potency of individual flavonoids were ranked as follows in a decreasing order; luteolin (18.4 $\mu$g/mL), myricetin (19.0 $\mu$g/mL) , rutin (22.2 $\mu$g/mL) , apigenin (24,3 $\mu$g/mL) , kaempferol (25.5 $\mu$g/mL). The protective effect of $\alpha$-tocopherol was substantially lower (highest $ED_{50}$value of 55.0 $\mu$g/mL) than all the other flavonoids, while the protective effect was highest in green tea and grape juice with low ED5O value of 7.6 and 5.3, respectively. These results suggest that flavonoids, especially quercetin, and natural compounds from food product, green tea and grape juice, produced powerful anti-oxidative activities, even stronger than $\alpha$-tocopherol. Taken together, supplementation of antioxidants to lymphocytes followed by oxidative stimulus inhibited damage to cellular DNA, supporting a protective effect against oxidative damage induced by reactive oxygen species.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.73-78
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• 2002

This study was conducted to investigate total protein, DNA, and RNA content in corpus luteum(CL) without and with central cavity in dairy cow. Stage of the estrous cycle of corpus luteum from slaughterhouse(CL3, days 11 to 17) was classified by method of Ireland et. al.(1980). Corpus luteum was classified into corpus luteum without(less than 2mm in diameter) and with central cavity(more than 2mm in diameter) by method of Kastelic et. al.(1990). 1 In total protein content, CL with central cavity did not differ from CL without central cavity. 2. In DNA content, CL with central cavity was significantly lower than CL without central cavity(p＜0.05). 3. In protein: DNA ratios, CL with central cavity was significantly lower than CL without central cavity(p＜0.05). 4. But in RNA content, protein:RNA and RNA:DNA ratios, CL with central cavity did not differ from CL without central cavity.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.33-37
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• 2004

In order to study the effect of temperature of denaturation, annealing and extension and cycles on amplification of DNA by PCR method, We isolated the hepatitis B virus DNA from hepatitis B patient blood and compared the density of DNA amplified by Reference PCR Program (denaturation at $94^{\circ}C$ for 30 sec., annealing at $60^{\circ}C$ for 1 min., extension at $72^{\circ}C$ for 1 min., holding at $72^{\circ}C$ for 5min., 30 cycles) that is usually used in laboratory to the density of DNA amplified by PCR program changed only the denaturation temperature or annealing temperature or extension temperature. We amplified about 341bp of hepatitis B virus DNA by Reference PCR Program from hepatitis patient blood, but the DNAs denatured at $72^{\circ}C$ or $60^{\circ}C$ were not detectable on photoradiography film. The DNA amplified at $37^{\circ}C$ of annealing temperature was not detectable, but the DNA annealed at $72^{\circ}C$ was detectable the lower density of DNA than the DNA amplified by Reference PCR Program. Each DNA amplified by PCR program changed only the extension temperature to $37^{\circ}C$ or $60^{\circ}C$ was almost same density as DNA amplified by Reference PCR Program. We compared the density of hepatitis B virus DNA amplified by Reference PCR Program for 30 cycles, 20 cycles, 10 cycles, and 5 cycles. The DNA cycled for 20 cycles was not amplified well as cycled for 30 cycles, but the DNA was detectable on the photoradiography film. The DNAs amplified for 10 cycles or 5 cycles were not detectable on photoradiorgaphy film. The concentration of hepatitis B virus DNA amplified in Reference PCR condition for 30 cycles, 20 cycles, 10 cycles, and 5 cycles were $72{\mu}g/m{\ell}$, $83{\times}10^{-3}{\mu}g/m{\ell}$, $27{\times}10^{-6}{\mu}g/m{\ell}$, and nondetectable, respectively.

• YAKHAK HOEJI
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• v.49 no.6
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• pp.484-489
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• 2005

Streptococcus pmeumoniae is the leading cause of pneumonia and bacterial meningitis. The current polysaccharide vaccine has been reported ineffective in elderly adults and children less than 2 years of age. Thus, in recent many researchers have been focused on a different approach, DNA vaccine. In our laboratory we developed a Streptococcus pneumoniae DNA (SPDNA) vaccine. This SPDNA vaccine was formulated by inserting the region encoding part of the capsule in the S. pneumoniae into the LAMP-1. In present work, with use of the SPDNA vaccine we attempted to establish a certain methodology useful for evaluation of effectiveness and immunoresponse of a DNA vaccine. Results showed that the subcutaneous route was the most effective for production of antisera specific for S. pneumoniae in mice. By isotyping analyses, IgM, IgGl, IgG2a, and IgG2b were determined. In addition, INF-$\gamma$ and IL-4 were predominantly detected. Combination of those data resulted in a pattern of IgGl < IgG2a=IgG2b and INF$\gamma\>$ >IL-4, which indicates the inmmunity towards the Thl response predominantly; furthermore, the SPDNA vaccination induced resistance of the CD4+T lymphocyte-depleted mice against disseminated pneumococcal infection. These data appear to be possibly due to activation of CDS8+T cell-activation. Taken together, this methodology can be applied for evaluating efficacy and mode of action of a DNA vaccine as minimum critera.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.29-33
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• 2005

A DNA vaccine methodology using eukaryote expression vectors to produce immunizing proteins in the vaccinated hosts is a novel approach to the development of vaccine and immuno-therapeutics, and it has achieved considerable success over several infectious diseases and various cancers. To further enhance its efficiency, attempts were made to develop novel plasmid vectors containing multiple immunostimulatory CpG motifs, for rapid and strong immune response. First, a 2.9 kb compact plasmid vector (pVAC), containing CMV promoter, polycloning site, BGH poly(A) terminator, ampicillin resistance gene and pBR322 origin was constructed. A pVAC-hEPO was also constructed, which contained a human erythropoietin gene, for evaluating the transfection efficiency of naked plasmid DNA both in vitro and in vivo. To examine the adjuvant effect of multi-CpG motifs on naked plasmid DNA, 22 and 44 enriched and unmethylated CpG motifs were introduced into pVAC to generate pVAC-ISS1 and pVAC-ISS2, respectively. $100{\mu}g$ of pSecTagB, pVAC, pVAC-ISS1 or pVAC-ISS2 were each injected intramuscularly into the tibilias anterior muscle of Balb/c mice. The level of interleukin-6 induced in the mice injected with pVAC-ISS1 and pVAC-ISS2 were significantly elevated after 12 hours, which were almost 2 and 2.5 times higher than that in the mice injected with pSecTagB, respectively. These results suggest that DNA vaccine plasmids with enriched CpG motifs can induce rapid secretion of interleukin-6 by lymphocytes. In conclusion, these vectors can contribute to the development of adjuvant-free DNA vaccinations against infectious diseases and various cancers.