• Journal of Ginseng Research
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• 제31권1호
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• pp.1-13
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• 2007

We found that the main bacterial metabolite M1 is an active component of orally administered protopanxadiol-type ginsenosides, and that the anti-metastatic effect by oral administration of ginsenosides may be primarily mediated through the inhibition of tumor invasion, migration and growth of tumor cells by their metabolite M1. Pharmacokinetic study after oral administration of ginsenoside Rb1 revealed that M1 was detected in serum for 24 h by HPLC analysis but Rb1 was not detected. M1, with anti-metastatic property, inhibited the proliferation of murine and human tumor cells in a time- and concentration-dependent manner in vitro, and also induced apoptotic cell death (the ladder fragmentation of the extracted DNA). The induction of apoptosis by M1 involved the up-regulation of the cyclin-dependent kinase(CDK) inhibitor $p27^{Kip1}$ as well as the down-regulation of a proto-oncogene product c-Myc and cyclin D1 in a time-dependent manner. Thus, M1 might cause the cell-cycle arrest (G1 phase arrest) in honor cells through the up/down-regulation of these cell-growth related molecules, and consequently induce apoptosis. The nucleosomal distribution of fluorescence-labeled M1 suggests that the modification of these molecules is induced by transcriptional regulation. Tumor-induced angiogenesis (neovascularization) is one of the most important events concerning tumor growth and metastasis. Neovascularization toward and into tumor is a crucial step for the delivery of nutrition and oxygen to tumors, and also functions as the metastatic pathway to distant organs. M1 inhibited the tube-like formation of hepatic sinusoidal endothelial (HSE) cells induced by the conditioned medium of colon 26-L5 cells in a concentration-dependent manner. However, M1 at the concentrations used in this study did not affect the growth of HSE cells in vitro.

• Journal of Microbiology
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• 제39권1호
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• pp.24-30
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• 2001

In addition to effecting the catalysis of sugar uptake, the bacterial phosphoenolpyruvate::sugar phosphotransferase system regulates a variety of physiological processes. In a previous paper [Seok et al.,(1997) J. Biol. Chem. 272, 26511-26521], we reported the interaction with and allosteric regulation of Esiherichia coli glycogen phosphorylase activity by the histidine-containing phosphocarrier protein HPr in vitro. Here, we show that the specific interaction between HPr and glycogen phosphorylase occurs in vivo. To address the physiological role of the HPr-glycogen phosphorylase complex, intracellular glycogen levels were measured in E. coli strains transformed with various plasmids. While glycogen accumulated during the transition between exponential and stationary growth phases in wildtype cells, it did not accumulate in cells overproducing HPr or its inactive mutant regardless of the growth stage. From these results, we conclude that HPr mediates crosstalk between sugar uptake through the phosphoenolpyruvate:sugar phosphotransferase system and glycogen breakdown. The evolutionary significance of the HPr-glycogen phosphorylase complex is suggested.

• 한국유기농업학회지
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• 제23권1호
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• pp.1-18
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• 2015

The purpose of this study is to examine the tendency of certified organic cosmetics market and the certification standards and regulations they are under, compare one of the most commonly used COSMOS-standard AISBL with the Korea Ministry of Food and Drug Safety (MFDS) organic cosmetic standard regulation. And then examining their differences and any potential issues is to present suggestions to be made as data for certification standard for natural & organic cosmetics in Korea regulation. This contents of study will be used as good research and development to promote the sustainable growth of the natural & organic cosmetic ingredients which have been grown by organic farmers certified. Also certified organic ingredients may help to growth the organic industry. I believe these are actual comparative for application to develop of natural and organic cosmetics in Korea as well the strengthening of the competitiveness of organic cosmetics certified in the world.

• 한국미생물·생명공학회지
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• 제14권4호
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• pp.293-298
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• 1986

Micromonospora inyoensis 균주에 의한 sisomicin의 발효에서 항생물질의 생산성에 대한 여러 가지 탄소원의 영향을 batch culture를 이용하여 검토하였다. Starch, dextrin 및 maltose는 sisomicin의 생산에 좋은 탄소원으로 밝혀졌으나, glucose가 사용되었을 때 sisomicin 생산성은 carbon catabolite regulation에 기인하여 그게 감소되었다. 한편 sisomicin생합성에 대한 carbon catabolite regulation은 catabolite inhibition효과보다 주로 catabolite repression 효과에 좌우되었다.

• 디지털융복합연구
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• 제12권7호
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• pp.103-112
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• 2014

새로운 기술 환경과 광고 환경을 바탕으로 탄생한 새로운 광고형태인 가상광고가 최근 본격적으로 집행되고 있다. 가상광고는 이전에 없었던 형태의 광고이며, 쉽게 프로그램 콘텐츠에 변화를 줄 수 있기 때문에 적절한 규제는 가상광고의 성장에 있어 매우 중요하다. 또한 시기적으로도 그 동안의 운용 결과를 바탕으로 전반적인 보완이 필요할 시점이다. 이러한 배경에서 2010년 이후 본격 진행되고 있는 가상광고의 규제에 대해 연구하였다. 먼저 가상광고의 성장과 효과에 대해 살펴보고 국내외의 가상광고 규제 현황을 파악하였으며, 가상광고 규제 관련 주요 쟁점들을 도출하여 보았다. 이를 바탕으로 향후 바람직한 가상광고 규제 방향을 제안하였다. 본 연구를 통하여 국내 가상광고 시장이 바람직한 방향으로 새로운 도약을 할 수 있는 계기가 되고 장기적인 성장을 이룰 수 있기를 기대해 본다.

• Journal of Cancer Prevention
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• 제23권4호
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• pp.170-175
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• 2018

Background: Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells. Methods: Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated. Results: Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5. Conclusions: These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

• BMB Reports
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• 제31권4호
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• pp.333-338
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• 1998

The sphingomyelin cycle and ceramide generation have been recognized as potential growth suppression signals in mammalian cells. Ceramide has been shown to induce differentiation, cell growth arrest, senescence, and apoptosis. Although the intracelluar target for the action of ceramide remains unknown, recent studies have demonstrated the role of cytosolic ceramideactivated protein phosphatase(CAPP). In this study, the cytotoxic effect of C2-ceramide, a synthetic cellpermeable ceramide analog, on HEp-2 cells and the mechanism by which ceramide induces cell death were investigated. The addition of exogenous C2-ceramide resulted in a concentration dependent cell death. Okadaic acid, a potent inhibitor of CAPP, enhanced ceramide-mediated cell death, which suggests that CAPP is not involved in this process. To understand the mechanism of action of ceramide, we studied the relationship between ceramide and c-Myc and pRb which are defined components of cell growth regulation. Western blot analyses revealed that C2-ceramide (10${\mu}M$) induced c-Myc down-regulation, but there were no significant changes in pRb. However, treatment of okadaic acid (10 nM) enhanced c-Myc and pRb down-regulation. Reduction of the amount of c-Myc and pRb occurred during HEp-2 cell death. These results suggest that the cytotoxic effect of ceramide in HEp-2 cells may not be mediated through the action of CAPP and that the downstream target for ceramide is c-Myc and pRb.

• 한국통신학회논문지
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• 제34권1B호
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• pp.34-46
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• 2009

The remarkable growth of Korean telecommunication market has based on the introduction of competition as well as mobile technology like CDMA. It was well Down that such a conspicuous growth has been towed by mobile service rather than fixed telephone service. In telecommunications service the number of subscribers to mobile was over 40 millions in 2006 and also, while the traffic amount of fixed telephone has been more decreased, that of mobile, which already outnumbers the fixed, has been constantly increased and will be much more in future. It will accelerate the substitution of access and call demand of fixed service by mobile. This change of technology and demand does affect directly the market performance of telecommunications. And regulation has also an effect on market structure, which finally affects on market performance. In this paper we suppose the fixed and mobile telecommunications services are in a same industry. After reviewing the relations among the demand, cost, charge structure and revenue structure in the one fixed and mobile telecommunications market using the framework of an industrial structure analysis, we discuss the current issues of telecommunications regulation and implications for the future regulation.

• BMB Reports
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• 제51권2호
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• pp.73-78
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• 2018

Vascular endothelial growth factor and its receptor (VEGF-VEGFR) system play a critical role in the regulation of angiogenesis and lymphangiogenesis in vertebrates. Each of the VEGF has specific receptors, which it activates by binding to the extracellular domain of the receptors, and, thus, regulates the angiogenic balance in the early embryonic and adult stages. However, de-regulation of the VEGF-VEGFR implicates directly in various diseases, particularly cancer. Moreover, tumor growth needs a dedicated blood supply to provide oxygen and other essential nutrients. Tumor metastasis requires blood vessels to carry tumors to distant sites, where they can implant and begin the growth of secondary tumors. Thus, investigation of signaling systems related to the human disease, such as VEGF-VEGFR, will facilitate the development of treatments for such illnesses.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.754-768
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• 2008

The past decades have seen enormous advances in our understanding of how GH acts. GH is a pituitary-derived polypeptide hormone that has diverse physiological effects including the regulation of bone growth, carbohydrate and lipid metabolism. The effects of GH are mediated directly and indirectly through IGF-I. In addition, GH stimulates the hepatic production of ALS. In postnatal life, IGF-I and -II circulate as 150 kDa ternary complexes consisting of one molecule each of IGFBP-3 or IGFBP-5, IGF-I or IGF-II and ALS. It is now known that ALS increases significantly the half-lives of the IGFs, IGFBP-3 and -5, and therefore is responsible for maintaining a circulating reservoir for each of these proteins.