• 한국미생물·생명공학회지
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• 제36권1호
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• pp.12-20
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• 2008

세포배양 유래 생물의약품 생산 공정에서 다양한 바이러스가 오염된 사례가 있기 때문에 바이러스 안전성 검증이 필수적이다. MVM은 동물 세포주와 동물 세포 배양 공정에 오염되는 대표적인 바이러스이다. 세포배양 유래 생물의약품의 MVM 안전성을 확보하기 위해, 세포주, 원료물질, 제조공정, 완제품에서 MVM을 정량적으로 검출하고, 제조공정에서 MVM 제거 검증을 위한 시험법으로 활용이 가능한 real-time PCR 시험법을 확립하였다. MVM에 특이적인 primer를 선별하였으며, 형광염료 SYBR Green I을 사용하여 MVM DNA 정량 검출 시험법을 최적화하였다. 세포배양 법에 의한 감염역가와 비교한 결과 real-time PCR 민감도는 $6{\times}10^{-2}TCID_{50}/mL$이었다. 확립된 시험법의 신뢰성(reliability)을 보증하기 위해 시험법 검증을 실시한 결과 특이성(specificity)과 재현성(reproducibility)이 우수함을 확인하였다. 확립된 real-time PCR을 생물의약품 제조공정 검증에 적용할 수 있는지 확인하기 위하여 인위적으로 MVM을 오염시킨 CHO 세포에서 MVM검출 시험을 실시한 결과 MVM을 감염시킨 CHO 세포와 세포배양 상청액에서 MVM을 정량적으로 검출할 수 있었다. 또한 바이러스 필터 공정에서 MVM제거 효과를 감염역가 시험법과 비교 검증한 결과 더 높은 민감도로 빠른 시간에 동일한 결과를 얻을 수 있었다. 위와 같은 결과에서 확립된 MVM real-time PCR시험법은 생물의약품 안전성 보증을 위한 세포주 검증, 생물의약품 생산 공정 검증, 바이러스 제거 공정 검증 등에서 감염역가 시험법을 대신할 수 있는 신속하고, 특이성과 민감성이 우수한 시험법임을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.31-32
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• 2011

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1303-1304
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• 2004

• Preventive Nutrition and Food Science
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• 제8권1호
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• pp.36-39
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• 2003

Many defined cell culture media were formulated over 3() years ago and may be deficient in certain micronutrients whose essentiality has only subsequently been recognised. The objective of this study was to evaluate whether alpha-minimal essential medium (MEM) supplemented with 10% foetal bovine serum contained sufficient selenium for optimal activity of the selenium containing enzymes cytosolic glutathione peroxidase (cGPx) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in cultured Chinese hamster ovary (CHO) cells. Additionally, the effect of zinc deficiency and metallothionein (MT) overexpression on cGPx and PHGPx activity was studied. The addition of 100 nM of selenous acid to the culture medium increased cGPx expression by 10-fold and PHGPx by about 2-fold in both wild-type CHO-K1 cells and CHO-K1 cells overexpressing mouse MT-1. Zinc deficiency had no significant effect on enzyme activity, but cells overexpressing mouse MT-1 had higher levels of cGPx activity. Zinc deficiency decreased cell survival but overexpression of MT-1 was partially protective, probably because its presence in quantity favoured the uptake, sequestration and cellular retention of any remaining zinc. This study demonstrates that selenium in complete alpha-MEM is insufficient for optimal cGPx and PHGPx activity and may compromise the cellular response to oxidative stress.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 춘계학술대회 및 국제심포지움 초록집
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• pp.204-204
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• 2005

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.151.1-151.1
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• 2003

B cell translocation gene-1 (Btg-1), originally discovered from chromosomal translocation in chronic B-cell lymphocytic leukemia. belongs to the APRO family. Btg-1 exhibit antiproliferative function. being expressed during the $G_{0}/G_{1}$ transition phase of cell cycle. Btg-1 is fully expressed in quiescent and differentiated cells. while the protein expression decreases as the cell progresses through the cell cycle. (omitted)

• Molecular & Cellular Toxicology
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• 제3권sup4호
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• pp.34.4-34.4
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• 2007

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.459-462
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• 2001

Angiopoietin-2 (Ang2) is a naturally occurring antagonist for angiopoietin-l (Angl) and its Tie2 receptor during vasculogenesis, Although angiopoietins have been expressed in several mammalian cell lines, their expression levels are low. Recombinant Chinese hamster ovary (CHO) cell lines expressing a high level of human Ang2 or its analog, human $Ang2_{443}$, with an amino-terminal FLAG-tag were constructed by transfecting the expression vectors into dhfr-deficient CHO cells and subsequent gene amplification in medium containing stepwise increments in methotrexate level. Secreted Ang2 or human $Ang2_{443}$ were purified from the cultured medium using an anti-FLAG- agarose affinity chromatography, The purified Ang2 and $Ang2_{443}$ migrated on SOS-PAGE as a broad band, characteristic of glycosylated protein. Their biological activity in vitro was demonstrated in a serum deprivation-induced apoptosis assay. Ang2 at high concentration, like AngI, can be an apoptosis survival factor for endothelial cells through the activation of the Tie2 receptor.

• 한국환경성돌연변이발암원학회지
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• 제24권3호
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.505-509
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• 2016

We have investigated the characteristics of amorphous silicon (a-Si) thin-film solar cell by inserting barrier layer. The conversion efficiency of a-Si thin-film solar cells on graphite substrate shows nearly zero because of the surface roughness of the graphite substrate. To enhance the performance of solar cells, the surface morphology of the back side were modified by changing the barrier layer on graphite. The surface roughness of graphite substrate with the barrier layer grown by plasma enhanced chemical vapor deposition (PECVD) reduced from ~2 um to ~75 nm. In this study, the combination of the barrier layer on graphite substrate is important to increase solar cell efficiency. We achieved ~ 7.8% cell efficiency for an a-Si thin-film solar cell on graphite substrate with SiNx/SiOx stack barrier layer.