• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.61-61
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• 1996

Taxol is used as cancer therapeutic agent. It has been known as weak posotive of chromosome aberration assay in vitro in our previous results (Ryu et al., 1996) and potent clastogens in the mouse bone marrow micronucleus (Tinwell and Ashby, 1994). We performed microgel electrophoresis to determine the effect of taxol and it's precursor 10-deacetyl baccatin III(DAB) on DNA. Microgel electrophoresis is useful, rapid, simple, visual, and sensitive technique for measuring DNA breakage and repair mechanisms in mammalian 근ells. The range of concentration used for taxol were 854, 427, 213.5, 106.8, 53.4 Ug/ml, for DAB 910 ,455, 227.5 U9/ml, Cell viability always exceed 85%. We analyzed the results by using the special software of image analyzer for this comet assay (Komet 3.0). By using this image analyzer software , we can get the result as the tail moment ((mean of tail length - mean of head lengh) x tail%DNA/100). A slight increase in DNA migration was observed for taxol at the concentration of 854 Ug/m4 in the absence of S9 mixture. No increased DNA migration was observed after treatment with DAB.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.130-136
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• 2008

Background: Human cytomegalovirus UL18, a MHC class I homologue, has been considered a natural killer (NK) cell decoy. It ligates LIR-1/ILT2 (CD85j), an NK inhibitory receptor, to prevent lysis of infected target cells. However, precise role of UL18 to NK cell cytotoxicity is yet elusive. Difficulty in clarifying the function of UL18 lies in complication in detecting UL18 mainly due to low level expression of UL18 on the surface and gradual loss of its expression. Methods: To overcome this hurdle, cDNA of cytoplasmic tail-less UL18 was constructed and expressed in swine endothelial cell (SEC). The expression level and its stability in the cell surface were monitored with FACS analysis. Results: Surface expression of UL18 is up-regulated by removing cytoplasmic tail portion from UL18F (a full sequence of UL18). SECs transfected with a cDNA of UL18CY (a cytoplasmic tail-less UL18) stably expressed UL18 molecule on the surface without gradual loss of its expression during 6 week continuous cultures. In the NK cytotoxicity assay, UL18 functions either inhibiting or activating NK cell cytotoxicity according to the source of NK cells. We found that there is individual susceptibility in determining whether the engagement of NK cell and UL18 results in overall inhibiting or activating NK cell cytotoxicity. Conclusion: In this study, we found that cytoplasmic tail is closely related to the regulatory function for controlling surface expression of UL18. Furthermore, by constructing stable cell line in which UL18 expression is up-regulated and stable, we provided a useful tool to clarify exact functions of UL18 on various immune cells having ILT2 receptor.

• The Korean Journal of Food And Nutrition
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• v.28 no.1
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• pp.34-39
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• 2015

In this study, portective effect on DNA damage several mushrooms (Pleurotus ostreatus, Flammulina velutipes, Lentinula edodes) according to cooking methods was investigated using Comet assay. Three edible mushrooms were cooked by grilling, blanching, pan-frying, or by preparing 'Jeon' (traditional Korean pancake). Cells were incubated in medium with 4 kinds of samples for 48 h ($37^{\circ}C$) were further treated with hydrogen peroxide ($H_2O_2$) for 5 min as an oxidative stimulus. Oxidative damage was evaluated by single-cell gel electrophoresis (Comet assay) and quantified by tail DNA% (TD), tail length (TL), tail moment (TM). Though oxidative DNA damages expressed as TD, TL, TM of 4 cooked samples were higher than raw sample, which means lower protective activities, all samples including raw sample had significantly higher protective effects than the positive control (p<0.05). The protective effect on DNA damage of cooked samples decreased much more when soybean oil added, likely due to the thermal oxidation of oil during cooking. Although heat treatment could degrade protective effect on DNA damage of mushrooms, the cooked mushroom had significant effect on oxidative stress. In conclusion, grilling and blanching were the most advantageous cooking methods to protect oxidative DNA damage induced by $H_2O_2$.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.19-24
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• 2001

Agricultural pesticides may cause certain biological risks since they are widely used to eradicate pests. Agricultural disasters may arise even from the possibility of their synergistic interaction with other harmful enviromnetal factors. The effect of pesticide on radiation-induced DNA damage in human blood lymphocytes was evaluated by the single cell gel electrophoresis (SCGE) assay. The lymphocytes, with or without pretreatment of the pesticide, were exposed to 0-2.0 Gy of $^60 CO$ gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed an excellent dose-response relationship. The present study confirms that the pesticide has the cytotoxic effect on lymphocytes and that it shows the synergistic interaction with radiation on DNA damage as well. The results may have a role of providing biological information necessary for the prevention of environmental disaster.

• 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.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.497-501
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• 1996

A gene coding for triosephosphate isomerase (TPI) from a rat skeletal muscle cDNA library was cloned and its nucleotide sequence was determined. The 1, 348-bp cDNA clone contains 24 bp $5^I$ noncoding region, the entire 750 bp coding region corresponding to a protein of 249 amino acids, $547bp 3^I$ noncoding region and part of a poly(A) tail. It also contains a polyadenylation signal, AATAAA, starting from 17 bp upstream of the poly(A) tail. The calculated molecular weight of rat TPI is 27.8 kDa and the net charge is +4. The deduced amino acid sequence from rat TPI CDNA sequence has 93% and 94% homology with that of mouse and human clones, respectively. The amino acids at the residue of Asn12, Lys14, His96, Glu 166, His96, His101, Ala177, Tyr165, Glu13O, Tyr2O9, and Ser212 in catalytic site are completely identical, confirming that the functional residues in TPI proteins are highly conserved throughout evolution. The most profound characteristic of rat TPI enzyme, compared with other TPIs, is that there are five cysteine substitutions at the residue of 21, 27, 159, 195 and 204. A Glu123 instead of Gly was found in rabbit, rhesus, mouse and human sequences. Through the method of RT-PCR, the mRNA transcription level of TPI gene was found to be different among various tissues and was highest in muscle.

• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.11.1-11.8
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• 2018

Interspecific hybridization experiments were conducted between the common seahorse Hippocampus kuda (male) and the slender seahorse H. reidi (female) during artificial rearing to develop a new aquarium fish with unique polyandrous mating. Molecular analysis via mitochondrial DNA (mtDNA) cytochrome b and nuclear DNA (ncDNA) ribosomal protein S7 gene supported the hybridization between the two species, and the hybrid also showed morphological characteristics of both species. Juveniles of H. kuda have dense melanophores on the whole body or only on the trunk and tail, whereas juveniles of H. reidi have thin melanophores on the whole body or present in stripes only along their prominent trunk and tail rings. However, all the hybrid juveniles had dense melanophores only on the tail, with the striped trunk rings, thus showing an intermediate pattern, and these patterns were limited to the fairly early stage of development (1-10 days old). In contrast, the two eye spines in the hybrid were apparent after 9 days old, which were not inherited from H. kuda (one eye spine), but from H. reidi (two eye spines). According to LOESS (local regression) analysis, the growth rate increased between 20 and 25 days, and the hybrids grew faster than H. kuda when they entered the explosive second phase of growth between 25 and 45 days for all the seahorses. This study highlights the hybridization between H. kuda and H. reidi may contribute to the improved taxonomic information of young seahorses.

• BMB Reports
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• v.38 no.2
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• pp.161-166
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• 2005

Functional protein of MB78 bacteriophage having apparent molecular weight of 22 kDa is expressed from 1.7 kb HindIII G fragment. The nucleotide sequence of this fragment showed two open reading frames of 222 and 196 codons in tail-to-tail orientation separated by a 62-nucleotide intercistronic region. The ORF of 22 kDa protein is present in opposite orientation, i.e. in the complementary strand, preceded by a strong ribosomal binding site and a promoter sequence. Another ORF started from the beginning of the fragment whose promoter region and translational start site lies in the 0.45 kb HincII U fragment which is located next to the HindIII G fragment, that has the sequence for DNA bending. 3' end of the fragment has high sequence homology to the EaA and EaI proteins of bacteriophage P22, a close relative of MB78 phage.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.84-85
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• 2006

This study was carried out to ascertain phylogenetic status of long-tail chicken which found recently in Korea and was presumed to be a kind of Korean Natives. 10 loci microsatellites were analysed for 449 birds of 11 groups and 2 region of mitochondrial DNA were sequenced for 135 birds of the same groups, that consist of 3 introduced breeds and 8 Korean Natives including 3 long-tail chicken. In mean numbers of alleles per locus(MNA) for microsatellites, long-tail chicken were smaller (2.60${\sim}$3.20) than the others, but in heterozygosities, were higher(0.4087${\sim}$0.5375) than others that were the same level of MNA. And in the neighbor joining bootstrap tree drawing by Nei's standard distance, they made a cluster with some Korean Native groups. All of the nucleotide sequences of mitochondrial cytochrome b gene and D-loop were classified into 23 haplotypes. In long-tail chicken, the haplotypes were 3 kinds, and were different among the groups (LTA, LTB and LTD). Resultly, it was supposed that 3 groups of the long-tail chicken be all a kind of Korean Natives.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.18-23
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• 2002

The detection characteristics of gamma-irradiated $(0{\sim}4\;kGy)$ soybeans produced in Korea and China were investigated by thermoluminescene (TL), electron spin resonance (ESR), and DNA comet assay. The TL glow curves were shown at around $200^{\circ}C$ for irradiated soybeans, while that at $280^{\circ}C$ for the non-irradiated one. The normalization with a re-irradiation step at 1 kGy could verify the above detection results. The Korean soybean showed higher glow curves than Chinese did. The ESR spectroscopy for husks of irradiated soybeans revealed specific signals (g = 2.02374, 1.98715) derived from cellulose radical, which intensities were proportional to irradiation does, with the higher peaks in Chinese sample than Korean one. The DNA comet for the non-irradiated sample showed no or little tails, while those for irradiated samples above 0.5 kGy were remarkably changed in their length, size, and concentration, thus resulting in distinguishing non-irradiated from irradiated samples. As a result, TL, ESR, and DNA comet determinations were found suitable for the detection of irradiated soybean at 0.5 kGy or more, and negligible differences were observed between Korean and Chinese origins in their detection characteristics.