• Journal of Nutrition and Health
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• v.37 no.4
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• pp.281-290
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• 2004

The purpose of this project was to evaluate whether daily fruit juice consumption could reduce the DNA damage in healthy subjects. The study was performed using 67 healthy volunteers (29 smokers, 38 nonsmokers) who were supple-mented with 480 m1 of grape juice for 8 weeks. Eight weeks of grape juice consumption did not change any anthropometric parameters. Lymphocyte DNA damage before the study was significantly greater (p<0.05) in smoker than nonsmoker, but, grape juice consumption significantly reduced DNA damage in both smoker (26%) and nonsmoker (I7%) to the level where there was no difference remained between the two groups after the intervention trial. This preventive effect of grape juice against DNA damage was not affected by sex of the subjects in non-smokers. Plasma $\alpha$-carotene, Iyco-pene and ${\gamma}$-totopherol was significantly increased after the trial in smokers, while erythrocyte catalase was significan-tly increased in both smokers and nonsmokers. Total radical-trapping antioxidant potential (TRAP) level in all subjects was significantly reduced after the intervention, while GSH-Px activity was increased only in nonsmokers. These results suggests that daily consumption of grape juice may protect DNA damage in peripheral lymphocytes, and supports the hypothesis that grape juice might exert their effect partially via a decrease in oxidative damage to DNA in humans partly by improving their antioxidative defense system.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.276-276
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• 2013

Here we report an integrated microdevice consisting of an efficient passive mixer, a magnetic separation chamber, and a capillary electrophoretic microchannel in which DNA barcode assay, target pathogen separation, and barcode DNA capillary electrophoretic analysis were performed sequentially within 30 min for multiplex pathogen detection at the single-cell level. The intestine-shaped serpentine 3D micromixer provides a high mixing rate to generate magnetic particle-pathogenic bacteria-DNA barcode labelled AuNP complexes quantitatively. After magnetic separation and purification of those complexes, the barcode DNA strands were released and analyzed by the microfluidic capillary electrophoresis within 5 min. The size of the barcode DNA strand was controlled depending on the target bacteria (Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium), and the different elution time of the barcode DNA peak in the electropherogram allows us to recognize the target pathogen with ease in the monoplex as well as in the multiplex analysis. In addition, the quantity of the DNA barcode strand (~104) per AuNP is enough to be observed in the laser-induced confocal fluorescence detector, thereby making single-cell analysis possible. This novel integrated microdevice enables us to perform rapid, sensitive, and multiplex pathogen detection with sample-in-answer-out capability to be applied for biosafety testing, environmental screening, and clinical trials.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.16-20
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• 1989

The effect of E. coli plasmid DNA sequences contained by chimeric vectors on plasmid replication was investigated. We constructed YRp7- or 2.$\mu$m circle-based plasmids containing E. coli plasmid DNA sequences and those not containing it. By examining their maintenance in yeast, we showed that plasmid without E. coli plasmid DNA sdquences was nore stable and presented higher copy number, and espressed higher level of hepatitis B viral surface antigen as a foreign gene. This result suggested that E. coli plasmid DNA sequences within chimeric plasmid somehow inhibited plasmid replication in yeast.

• BMB Reports
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• v.38 no.1
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• pp.97-103
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• 2005

Under the condition of expression of $\lambda$ P protein at lethal level, the oriC DNA-binding activity is significantly affected in wild-type E. coli but not in the rpl mutant. In purified system, the $\lambda$ P protein inhibits the binding of both oriC DNA and ATP to the wild-type DnaA protein but not to the rpl DnaA protein. We conclude that the $\lambda$ P protein inhibits the binding of oriC DNA and ATP to the wild-type DnaA protein, which causes the inhibition of host DNA synthesis initiation that ultimately leads to bacterial death. A possible beneficial effect of this interaction of $\lambda$ P protein with E. coli DNA initiator protein DnaA for phage DNA replication has been proposed.

• Journal of fish pathology
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• v.16 no.3
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• pp.147-152
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• 2003

The CMV promoter driven luciferase reporter gene coding plasmid (pcDNA-luc) was constructed and used as a model for DNA immunization study. Expression of the recombinant luciferase protein was confirmed in vitro in RTG-2 cell line before using in vivo study in olive flounder. In dose response study, the maximum expression of the luciferase gene was found in the group injected with 10-15μg of plasmid DNA. The kinetic study showed that the luciferase gene expression was reached at the maximum level at one day after injection and slightly decreased after then but significantly high level of expression was sustained until the conducted experiment of 7 days. In the study of tissue distribution of gene expression, it was found that luciferase gene was expressed at the significant level in immune organs such as gill and spleen, located far from the injected site, suggesting the systemic distribution of the intramuscularly injected DNA in olive flounder.

• Genomics & Informatics
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• v.10 no.3
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• pp.206-211
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• 2012

DNA barcoding has been widely used in species identification and biodiversity research. A short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence serves as a DNA bio-barcode. We collected DNA barcodes, based on COI sequences from 156 species (529 sequences) of fish, insects, and shellfish. We present results on phylogenetic relationships to assess biodiversity the in the Korean peninsula. Average GC% contents of the 68 fish species (46.9%), the 59 shellfish species (38.0%), and the 29 insect species (33.2%) are reported. Using the Kimura 2 parameter in all possible pairwise comparisons, the average interspecific distances were compared with the average intraspecific distances in fish (3.22 vs. 0.41), insects (2.06 vs. 0.25), and shellfish (3.58 vs. 0.14). Our results confirm that distance-based DNA barcoding provides sufficient information to identify and delineate fish, insect, and shellfish species by means of all possible pairwise comparisons. These results also confirm that the development of an effective molecular barcode identification system is possible. All DNA barcode sequences collected from our study will be useful for the interpretation of species-level identification and community-level patterns in fish, insects, and shellfish in Korea, although at the species level, the rate of correct identification in a diversified environment might be low.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.147-156
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• 2010

There are four key factors for gas-phase biofilters; biocatalysts(microorganisms), packing materials, design/operating techniques, and diagnosis/management techniques. Biofilter performance is significantly affected by microbial community structures as well as loading conditions. The microbial studies on biofilters are mostly performed on basis of culture-dependent methods. Recently, advanced methods have been proposed to characterize the microbial community structure in environmental samples. In this study, the physiological, biochemical and molecular methods for profiling microbial communities are reviewed, and their applicability to biofilters is discussed. Community-level physiological profile is based on the utilization capability of carbon substrate by heterotrophic community in environmental samples. Phospholipid fatty acid analysis method is based on the variability of fatty acids present in cell membranes of different microorganisms. Molecular methods using DNA directly extracted from environmental samples can be divided into "partial community DNA analysis" and "whole community DNA analysis" approaches. The former approaches consist in the analysis of PCR-amplified sequence, the genes of ribosomal operon are the most commonly used sequences. These methods include PCR fragment cloning and genetic fingerprinting such as denaturing gradient gel electrophoresis, terminal-restriction fragment length polymorphism, ribosomal intergenic spacer analysis, and random amplified polymorphic DNA. The whole community DNA analysis methods are total genomic cross-DNA hybridization, thermal denaturation and reassociation of whole extracted DNA and extracted whole DNA fractionation using density gradient.

• Environmental Mutagens and Carcinogens
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• v.7 no.2
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• pp.59-64
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• 1987

Cytotoxic and genotoxic potential of monosodium glutamate (MSG) were evaluated in primary cultures of rat hepatocytes. When exposed to liver cell culture continuously for 24 hr, MSG did not show any cytotoxic effects up to 0.5% (w/v) level as determined by Tryphan Blue exclusion and lactic dehydrogenase release test. MSG also did not induce unscheduled DNA synthesis or DNA single-strand breaks in hepatocyte cultures up to 1% level. No synergistic effects of MSG were observed on aflatoxin B$_1$-induced DNA damage when 1% MSG was treated to liver cell culture along with aflatoxin B$_1$.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.186-191
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• 2002

The usefulness of oligonucleotide DNA chip was evaluated for detection and primary level identification of major waterborne viruses in environmental samples. The enteric waterborne viruses included enterovirus, adenovirus, and rotavirus. Total intracellular RNA of 10 BGM cell plates showing virus-specific cytopathic effects was extracted at the third day after inoculation. The intracellular RNA was then subjected to either enterovirus-specific RT-PCR followed by sequencing analysis, or the DNA chip. Seven out of 10 positive samples in cell culture were positive but the other three sample were turned out to be negative by both RT-PCR and DNA chip analyses. Nucleotide sequencing results and the DNA chip hybridization results of the RT-PCR product were in complete agreement in the identification of the 7 positive samples as enteroviruses. Using the DNA chip, it took only 3∼4 hr to complete detection and primary level identification of target viruses and additional procedures such as gel electrophoresis or nucleotide sequencing were not necessary. We believe that the DNA chip system can be employed as a highly effective and new detection methodology for environmental viruses.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.117-123
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• 1997

Viral coat protein (CP) encoding cDNA with artificial start and stop codons was synthesized by reverse-transcriptase polymerase chain reaction (RT-PCR) from the Korean isolate of potato virus Y-vein nectrosis strain (pVY-VN). To make PVY CP cDNA to untranslatable form, three stop codons were inserted near the start codon by "megaprimer-PCR" method. The untranslatable CP cDNA was subcloned to plant expression vector and transferred to N. tabacum cv. NC82 by Agrobacterium-mediated transformation. Highly resistant plants to PVY infection were screened, based on symptom development after mechanical virus inoculation. By genomic PCR and Southern blot analysis, one or more copies of the untranslatable CP gene were found in all transformants. From northern blot analysis, highly resistant transgenic lines had very low level of CP transcript but susceptible lines had high level, suggesting resistance to PVY infection should be related to RNA-mediated mechanism.mechanism.