• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.53-56
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• 2002

Mammalian cell based biosensor kits are expected to be in assessment of samples toxicity more sensitive and accurate. A recombinant fluorescent Chinese Hamster Ovary (CHO) cell line was known to be responsive to the various toxicants Specially. KFC- AlO cell line. which contain the c-fos SRE::GFP plasmid (pKFG). was found to be able to detect toxicants sensitively. A biosensor kit was developed by using an immobilized KFC-A10 cell line. Immobilized recombinant fluorescent cells within agarose, known as a representative hydrogel matrix, have been maintained in the matrix viably and have shown constant fluorescent levels for long time. Immobilized cells have shown the ability to detect the chemical toxicity in the keep of fluorescent level as the metabolism is inhibited under toxic conditions.

• Journal of fish pathology
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• v.16 no.2
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• pp.125-129
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• 2003

Conncxin (Cx) is an important and essential protein induction of oocyte maturation, which is present in almost all mammalian tissucs except cirulating blood cells and adult skeletal museles. In this study, goldfish Cx43 cDNA sequence is available in GenBank under the accession number AB078505. Homology analyses using the GenBank and EMBL general database searches indicated that goldfish Cx43 cDNA has a high homology with carp Cx43 (95.1% identity), zebrafish Cx43 (90.5% identity), and chicken Cx43 (81.9% identity). Goldfish Cx43 is similar to the Cx family in its general features, and all the typical Cx consensus sequences are also found. Moreover, significantly increased Cx43 transcrpts were observed in mature goldfish (GSI; 18.3-21.7) pituitary and ovary when compared with immature goldfish (GSI; 4.9-6.0). Cx43 transeripts were weakly detectrd in both liver and kidney of immature and mature goldfish. There is possible that Cx43 nctivity was relation to oocyte maturation in the goldfish.

• Reproductive and Developmental Biology
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• v.39 no.1
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• pp.1-6
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• 2015

Luteolysis is a cyclical regression of the corpus luteum in many non-primate mammalian species. Prostaglandin $F_2{\alpha}$($PGF_2{\alpha}$) from the uterus and ovary induces functional and structural luteolysis in bovine. The action of $PGF_2{\alpha}$ is mediated by $PGF_2{\alpha}$ receptor located on the luteal steroidogenic and endothelial cell membranes. $PGF_2{\alpha}$ plays an important role in regulating nitric oxide production in endothelial cells of the bovine corpus luteum. Nitric oxide production and nitric oxide synthase activity are stimulated and induced by $PGF_2{\alpha}$ in luteal endothelial cells. Moreover, the reactive oxygen species inhibits progesterone secretion in bovine luteal cells and induces apoptosis. Thus, the interaction between $PGF_2{\alpha}$ and reactive oxygen species provides important aspects in physiology of the corpus luteum forfunctional and structural luteolysis.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.170.3-171
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• 2003

An efficient Erythropoietin (EPO)-expression system in mammalian cells is required for massive production for therapeutic use. Ammonium ion is a major problem in the production of valuable recombinant proteins in cultured animal cells. Therefore, it is of importance to devise a system by which a high productivity of human therapeutic recombinant protein can be maintained or enhanced under low ammonium concentration. To reduce the ammonium ion accumulated in EPO producing Chinese Hamster Ovary (CHO) ceels, IBE, we introduced the first two genes of the urea cycle, carbamoyl phosphate synthetase (CPSI) and arnithine transcarbamoylase (OTC), into IBE using a stable transfection method. (omitted)

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.63-69
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• 1990

To study the follicular atretic mechanism in mammalian ovary, the medium-sized (3.0-6.0mm) follicles of porcine ovary were morphologically classified as nonnal and atretic. Steroid concentrations in the follicular fluid were analyzed by radioimmunoassay, and the proteins in that fluid were electrophoretically separated. Concentrations of progesterone in the atretic follicular fluid of follicular phases were higher than those of normal ones (p < 0.05). Concentrations of testosterone were high in normal luteal and atretic follicular-phases follicles. The concentrations of estradiol remained significanily lower in atretic follicular-phases follicles than normal. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of follicular fluid proteins, four kinds of proteins (20K, 32K, 33K, 38K) were detected, and those proteins were not present in sera. According to the ovarian cycle, proteins of MW of 112K and 141K were identified. In atretic follicular fludies, MW of 23K and 24K were specifically detected. From the above results, we can conclude that, as ovarian cycle changes, steroid contents and protein composition in atretic follicular fluid are different from the normal developing follicular fluid. To further understand the physiologic roles of the proteins present in the atretic follicular fluids, these proteins need to be characterized and identified.

• Animal cells and systems
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• v.5 no.1
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• pp.77-83
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• 2001

The present study was conducted to elucidate whether the expression level of poly(ADP-ribose) polymerase (PARP) is related to the ultraviolet radiation (UV)-induced apoptosis. After treatment of the mammalian cell lines HeLa S3 and Chinese hamster ovary (CHO) with 50 J/m2 UV, induction of apoptosis was determined by several means during 24 h post-incubation. Incidence of apoptosis was much lower in CHO than HeLa S3 cells based on the percentage of apoptotic cells in terms of morphological changes in nucleus or direct counting of viable cells and qualitative or quantitative DNA fragmentation. Interestingly, when the expression level of PARP was measured by western blotting, the amounts of PARP that was retained at each time point inversely correlated with the incidences of apoptosis in these cells. Concomitant with generation of the 85 kDa fragment, 116 kDa PARP disappeared in HeLa S3 within 6 h after UV treatment, whereas a fair amounts of 116 kDa band was still retained in CHO cells at 36 h post-incubation. This inverse relationship was also observed in the adaptive response system, in which cells weve treated with a high dose of UV after pretreatment with a low dose. As expected, typical adaptive responses appeared in CHO cells but not in HeLa cells, showing greater cell viability and lesser DNA fragmentation. During the adaptive response in CHO cells, PARP was expressed at much higher level compared to the single, high dose-treated cells. Interestingly, even though PARP was induced at 6 h post-incubation In both cell types, its expression was more prominent in CHO cells. Thus, our data indicate that the retained level of intact PARP against UV damage inversely correlates with incidence of apoptosis in mammalian cells, and also suggest that a machinery to protect the PARP degradation against UV damage exists in CHO but not in HeLa S3 cells.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.695-703
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• 2006

The dissolved oxygen level of any cell culture environment has a critical effect on cellular metabolism. Specifically, hypoxia condition decreases cell viability and recombinant protein productivity. In this work, to develop CHO cells producing recombinant protein with high productivity, mammalian expression vectors containing a human tissue-type plasminogen activator (t-PA) gene with hypoxia response element (HRE) were constructed and stably transfected into CHO cells. CHO/2HRE-t-PA cells produced 2-folds higher recombinant t-PA production than CHO/t-PA cells in a $Ba^{2+}-alginate$ immobilized culture, and 16.8-folds in a repeated batch culture. In a non-aerated batch culture of suspension-adapted cells, t-PA productivity of CHO/2HRE/t-PA cells was 4.2-folds higher than that of CHO/t-PA cells. Our results indicate that HRE is a useful tool for the enhancement of protein productivity in mammalian cell cultures.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.3.1-3.8
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• 2013

Objectives We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. Methods Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration ($0.2{\mu}m$ pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. Results Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from $0.01{\mu}g/mL$ to $10{\mu}g/mL$). In particular, MN induction was affected by cytoB. Conclusions All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6357-6362
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• 2012

Background: To determine the prevalence of mammalian target of rapamycin phosphorylation (p-mTOR) and vascular endothelial growth factor (VEGF) and any correlation with clinical characteristics and prognosis in ovarian clear cell carcinoma patients. Materials and Method: Seventy four paraffin-embedded specimens of such carcinomas frompatients who underwent surgery, received adjuvant chemotherapy and were followed up at King Chulalongkorn Memorial Hospital during January 2002 to December 2008 were stained with rabbit monoclonal IgG p-mTOR and rabbit polyclonal IgG VEGF using immunohistochemical methods. Medical records were reviewed and clinical variables were analysed. Results: The prevalence of positive p-mTOR in ovarian clear cell carcinoma was 87.9% and significantly higher in advance-stage than early-stage patients (100% versus 83.6%, P<0.05). Two-year disease free survival and 2-year overall survival in patients with positive p-mTOR expression were 60% and 69.2% with no differences from patients with negative p-mTOR expression (p>0.05). The prevalence of VEGF expression was 63.5% and significantly higher in chemo-sensitive than chemo-resistant patients (70.7% versus 37.5%, P<0.05). Two-year disease free survival and 2-year overall survival in patients with VEGF expression were 72.3% and 83% respectively which were significantly different from patients with negative VEGF expression (p<0.05). Conclusions: p-mTOR expression in ovarian clear cell carcinoma was significantly correlated with the stage of disease. VEGF expression was significantly correlated with chemosensitivity, and survival. Further studies of related targeted therapy might be promising.

• The Journal of Korean Medicine
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• v.32 no.1
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• pp.67-83
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• 2011

Objectives: The purpose of this study was to examine the single dose toxicity with oral administration and genotoxicities of Ssanghwa-tang fermented with Lactobacillus acidophyllus. Materials and Methods: Clinical signs, weight changes, lethal doses$(LD_{50})$, and postmortem evaluation were determined by Globally Harmonized Classification System(GHCS) in a single-dose oral toxicity study. In vitro mammalian chromosomal aberration test was conducted with Ames test by cell proliferation suppression assessment using the cultivated CHO-K1(Chinese hamster ovary fibroblast) origins. Bacterial reversion assay was performed using Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and Escherichia coli (WP2uvrA). In vivo micronucleus test was performed using ICR mouse bone marrow. Results: No clinical sign was observed and none of the groups with doses up to 2000 mg/kg showed significant acute oral toxicity in the single dose oral administration. None of the sample doses taken during the 6 to 18 hour groups showed significant aberrant metaphases comparing to the negative control group in the in vitro mammalian chromosomal aberration test. No evidence of mutagenicity was seen for Escherichia coli (WP2uvrA) or Salmonella typhimurium (TA98, TA100, TA1535, and TA1537). No significant increase in the frequency of micronuclei was seen in the micronucleus test. Conclusion: These results indicate that the $LD_{50}$ value of Ssanghwa-Tang fermented with Lactobacillus acidophyllus may be over 2000 mg/kg and it have no acute oral toxicity and genotoxicity.