• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.153-153
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• 2001

Nitric oxide (NO) has multifaceted roles in carcinogenesis. Besides acting as an initiator, NO may also playa role in the promotional stage of tumorigenesis or neoplastic transformation. In line with this notion, our previous studies have revealed that the tumor promotor phorbol ester induces expression of inducible nitric oxide synthase (iNOS) and NO production in mouse skin.(omitted)

• Microbiology and Biotechnology Letters
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• v.25 no.6
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• pp.586-591
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• 1997

In the course of screening for the tipA promoter-inducing substances, we isolated an active compound, sulfomycin Ia, from the mycelium of a microorganism designated 50634. The producing organism was identified as Streptomyces sp. on the basis of taxonomic studies. Sulfomycin Ia was purified from mycelial extract by silica gel column chromatography, LH-20 column chromatography, silica gel TLC, and preparative HPLC. The molecular weight of sulfomycin Ia was determined to be m/z 1129 (M+Na)$^{+}$ by FAB mass measurement and $^{1}$H NMR spectroscopic analysis. The structure was assigned as a derivative of sulfomycin I with thiazole, methyloxazole, oxazole, and pyridine rings by $^{1}$H NMR spectral data.

• KSBB Journal
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• v.5 no.3
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• pp.195-200
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• 1990

The growth behavior of recombinant Escherichia coli cells having plasmid pIF-III-B, which carries human alpha-interferon gene under the control of lpp promoter, lac promoter and lac operator, was studied by using of various E. coli host strains. Expression of the alpha-IFN gene is controllable by using inducer IPTG because the plasmid also contains lacI gene which produces lac regressors. The repressors block the transcription of alpha-IFN gene. There were considerable differences in cell growth according to the host strains used. Cell growth was inhibited not only by plasmid pIF-III-B itself but also by the induction of alph-a-IFN gene expression. Growth inhibition caused by the plasmid itself was more serious than that caused by the induction of alpha-IFN gene expression.

• Toxicological Research
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• v.13 no.4
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• pp.367-370
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• 1997

Fumonisin $B_{1}$ ($FB_{1}$) is hepatotoxic in all species, and initiator and promotor for hepatocarcinogenesis produced mainly by Fusarium moniliforme. This fungus is commonly natural contaminant of corn and other grains worldwide, and has been associated with animal and human diseases. In these study, natural occurrence of $FB_{1}$ was surveyed in 30 healthy domestic corn kernels in Chonbuk and Kangwon province, harvested in 1994 and intended for human consumption, and 15 imported American and Chinese samples of each, collected from different ship-loading at Inchon harbor for animal foodstuffs. $FB_{1}$ contents were measured by high-performance liquid chromatography (HPLC) with a fiourescence detector. The data revealed that 2 out of 12 corn kernels from Kangwon province with 1.1 and 0.7 ppm, and 2 out of 18 corns from Chonbuk province with 0.5 and 1.3 ppm, respectively. However, there was no detection of $FB_{1}$ in imported corn samples, even though those were visibly moldy.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.76-76
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• 1995

Virus-encoded HIV-1 reverse transcriptase (RTase) is one of the major targets for the development of drugs for HIV-1 since it is an essential enzyme-for the replication cycle of HIV-1. We cloned the entire reverse trancriptase gene into an inducible expression vector with tac promotor= RTase was stably overexpressed and induced by IPTG and the highly-expressed RTase was purified partially by use of DEAE cellulose and Mono Q column. The partially purified enzyme (663kDa, 51kDa) as exhibited by SDS-PAGE showed the high specific activity (16,570U/mg) when the assay for the RTase activity was carried out using $^3$H-dTTP and poly(rA): oligo(dT)12-18 as the substrate.

• 한국디지털정책학회:학술대회논문집
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• 2003.12a
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• pp.465-477
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• 2003

본 연구에서는 농촌지역정보화 사업에 대한 추진주체를 바탕으로 한 '민간주도형' 농촌지역정보화 마을과 '정부주도형' 농촌지역정보화마을간의 운영상의 차이점을 사례연구를 통하여 비교 분석하였다. 민간주도형인 경우, 자생력, 커뮤니티, 다양한 아이디어 창출 등의 측면에서 강점을 보인 반면, '정부주도형'인 경우, 확산속도, 사이트 운영, 하드웨어 보급 등의 측면에서 강점을 나타냈다. 이러한 비교분석을 통해 본 연구에서는 농촌지역정보화의 성공적 운영을 위한 유용한 가이드라인을 제공하고자 한다. 특히 지역정보화 사업을 추진하는 정부, 지방자치단체, 지역주민에게 방향설정을 제시해 줄 것이다.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.165-172
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• 1987

An expression vector in a mammalian cell was constructed using the origin of replication (OR) and the promoters of SV40. The plasmid pSVOE was constructed by inserting SV40 DNA fragment (1, 118bp) containing SV40 OR and promoters into pBR322-1, and then a multiple cloning sequence was inserted at the immediate downstream of the late promoter of SV40 in the pSVOE vector. The plasmid was named pSVML. As a selection marker, thymidine kinase gene of herpes simplex virus with its promoter was inserted into EcoRI site of pSVML and the recombinant was named pSVML-TKp. To test the expression capacity of foreigen gene inserted at the multiple cloning site of pSVML, the thymidine kinase gene without its own promoter was inserted at the BamHI site of pSVML. The recombinant was named pSVML-TK. These plasmids, pSVML-TKp and pSVML-TK, were transfected into COS cells with calcium phosphate precipitation method. The thymidine kinase activity was significantly increased in both transfected cells.

• Molecules and Cells
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• v.44 no.8
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• pp.569-579
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• 2021

Cyclase-associated protein 2 (CAP2) has been addressed as a candidate biomarker in various cancer types. Previously, we have shown that CAP2 is expressed during multi-step hepatocarcinogenesis; however, its underlying mechanisms in liver cancer cells are not fully elucidated yet. Here, we demonstrated that endoplasmic reticulum (ER) stress induced CAP2 expression, and which promoted migration and invasion of liver cancer cells. We also found that the ER stress-induced CAP2 expression is mediated through activation of protein kinase C epsilon (PKCε) and the promotor binding of activating transcription factor 2 (ATF2). In addition, we further demonstrated that CAP2 expression promoted epithelial-mesenchymal transition (EMT) through activation of Rac1 and ERK. In conclusion, we suggest that ER stress induces CAP2 expression promoting EMT in liver cancer cells. Our results shed light on the novel functions of CAP2 in the metastatic process of liver cancer cells.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.78-83
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• 1998

Anticarcinogenicity of 12 kinds of colored rice cultivars was investigated in vitro with Ilpumbyeo as a control. Pigment and hexane fractions were prepared from the rice brans through extraction with 80% ethanol containing 0.5% TFA or n-hexane to use subsequent evaluation of their anticarcinogenic effect by determining inhibitory activity against DNA strand scission and tumor promotion, as well as antimutagenic activity using SOS chromotest system. Antimutagenic activity of the pigment fractions was revealed to decrease in order of LK1B4-12-1-1 > Sanghaehanghyulla > HP833-1-3-1-1 > Chokoto14 > Jagwangdo > Jajin > Kilmheugmi > Tiwan-Tsi-C > Heugjinmi > Linsia-Shoea-Dau > Suweon425 > Suweon415. The activity of the hexane fractions decreased in order of LK1B4-12-1-1 > Sanghaehyanghyulla>Ilpunibyeo > HP833-1-3-1-1 > Chokoto14 > Jagwangdo > Jajin > Linsia-Shoea-Dau >Tiwan-Tsi-C > Heugjinmi > Suweon425, Kilimheugmi > Suweon415. Results showed that inhibitory activity against DNA strand scission in the pigment fractions decreased in order of HP833-1-3-1-1 > Tiwan-Tsi-C > Jajin > Chokoto14 > Suweon425 > Heugjinmi > LK1B4-12-1-1 > Suweon415 > Jagwangdo > Kilimheugmi > Linsia-Shoea-Dau > Sanghaehyanghyulla. On the other hand, the activity of the hexane fractions decreased in order of LK1B4-12-1-1 > Suweon 415 > Kilimheugmi > Chokoto14 > Heugjinmi > Jajin > Suweon425 > Tiwan-Tsi-C > Sanghaehyanghyulla a Linsia-Shoea-Dau > Jagwangdo > HP833-1-3-1-1 > Ilpumbyeo. Experiment using the short-term assay for promotor substance showed that inhibitory activity contained in the pigment fractions against rumor promotor TPA decreased in order of Linsia-Shoea-Dau > Kilimheugmi > HP833-1-3-1-1, Suweon425 > Heugjinmi > Jajin > Chokoto14 > Sanghaehyanghylla > Suweon 415 > LK1B4-12-1-1 > Tiwan-Tsi-C > Jagwangdo.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.94-105
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• 2001

Background : Examining the biological susceptibility of Mycobacterium tuberculosis to pyrazinamide (PZA) in vitro is very difficult as PZA is inactive under normal culture conditions. The biological susceptibility test, an enzyme assay for Pzase activity, and a genetic test for pncA gene mutations, were performed in order to predict PZA resistance. Methods : 28 cultured clinical isolates of Mycobacterium tuberculosis were tested. The biological susceptibility was performed by the absolute concentration method using Lowenstein-Jensen media. The PZase activity was tested by means of Wayne's method. A 710-bp region includes the entire open reading frame of pncA was amplified and sequenced. Results : All six strains with positive PZase activity exhibited no pncA mutations with one strain showing a false resistance in the biological susceptibility test. Among the 22 strains with no PZase activity, 21 exhibited showed pncA mutations. In the biological susceptibility test, 20 strains were resistant, and one was susceptible, and the other flied to test. The mutation types varied with ten missense, one silent and one nonsense mutation 1 slipped-strand mispairing, and 6 frameshift mutations. Three strains had an adenine to guanine mutation at position -11 upstream of the start codon. Conclusion : The mutation at the pncA promotor region is frequent at -11 upstream position. Automatic sequencing of pncA is a useful tool for rapid and accurate detection of PZA resistant M. tuberculosis, and for demonstrating the epidemiological relatedness of the PZA resistant M. tuberculosis strains.