• Journal of dental hygiene science
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• v.17 no.5
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• pp.433-438
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• 2017

Relative to its incidence, oral cancer has serious negative social effects. The exact causes of oral cancer have not been clarified, but many studies have implicated smoking and drinking. However, the fundamental mechanism of oral cancer causation has yet to be elucidated. Lysophosphatidic acid (LPA) augments epithelial mesenchymal transition (EMT) and development of various cancer cells. However, a detailed mechanistic explanation for LPA-induced EMT and the effects of EMT-promoting conditions on oral squamous cell carcinoma development remain elusive. In the present study, a quantitative reverse transcription polymerase chain reaction was used to analyze TWIST1, Slug, E-cadherin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript expression. Immunoblotting was used to analyze TWIST1, Slug, E-cadherin, and GAPDH protein expression. siRNAs were used to silence TWIST1 and Slug transcript expression. A matrigel-coated in vitro invasion insert was used to analyze oral cancer cell invasion. The results of the present study show that the expression levels of TWIST1 and Slug, which are EMT factors, were increased by LPA treatment in YD-10B oral squamous cell carcinoma. Conversely, E-cadherin expression was significantly reduced. In addition, transfection of the cells with TWIST1 and Slug siRNA strongly inhibited LPA-induced oral cancer cell invasion. The present study shows that TWIST1 and Slug mediate LPA-induced oral cancer cell EMT and invasiveness. The present study confirmed the mechanism by which LPA promotes oral cancer cell development, with TWIST1 and Slug providing novel biomarkers and promising therapeutic targets for oral cancer cell development.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.1
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• pp.14-19
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• 2012

Purpose: We analyzed the oncologic outcome of the malignant transformed benign giant cell tumor of bone. Materials and Methods: Between January 2000 and February 2012, 5 cases were referred with suspicious malignant transformation of benign giant cell tumor. No patients underwent radiation therapy. Results: After referral, all patients received the wide excision of the tumor and its' pathologic diagnosis were osteosarcoma. As classified by the location of tumor lesion, 3 cases were located in the distal femur, 1 case was in the distal radius and 1 case was in the proximal femur. The average latent period between diagnosis of benign giant cell tumor and diagnosis of secondary malignant giant cell tumor was 49.2 months. (range, 24-126 months) The mean follow-up period was 21.6 months. There were subsequent local recurrence in 2 cases and 3 patients developed distant metastasis. All patients with lung metastasis were dead. Conclusion: Malignant transformation of benign giant cell tumor of bone can be occurred within 5 years. Therefore, when benign giant cell tumor suspicious malignant transformation, it is necessary to do more aggressive treatment.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.117-127
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• 2001

The high-level expression of a human single chain urokinase-type plasminogen activator (scu-PA) was achieved by employing a methotrexate (MTX)-dependent gene amplification system in Chinese hamster ovary (CHO) cells. By cotransfecting and coamplifying a scu-PA expression plasmid and dihydrofolate reductase (DHFR) minigene, several scu-PA expressing CHO cell lines were selected and gene-amplified. These recombinant cell lines, NGpUKs, secreted a completely processed scu-PA of 54 kD and up to 60mg/L was accumulated in the culture medium when they were adapted to an optimal MTX concentration. Over 95% of the scu-PA expressed was secreted in the culture medium and identified having the proper function of a plasminogen activator when activated by plasmin. Based on a genomic Southern analysis, a representative subclone, MGpUK-5, exhibited MTX-dependent scu-PA gene amplification, plus the initial single-copy gene of scu-PA eventually turned into about 150 copies of the amplified gene of scu-PA after gradual adaptation to 2.0$\mu$M of MTX. Meanwhile, the transcripts kof the scu-PA gene increased, although -early saturation of transcription was identified at 0.1$\mu$M of MTX. The scu-PA production by the MGpUK-5 subclone also increased relative to the gene amplification and increased transcripts, however, the relationship was not linearly proportional. Accordingly, since the MGpUK cell lines expressed elevated levels of enzymatically active scu-PA, these cell lines could be applied to the largescale production of scu-PA.

• Journal of Power Electronics
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• v.11 no.1
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• pp.82-89
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• 2011

Differences in the frequency characteristic applied to a ripple current may shorten fuel cell life span and worsen the fuel efficiency. Therefore, this paper presents an experimental analysis of the ripple current applied variable frequency characteristic in a polymer electrolyte membrane fuel cell (PEMFC). This paper provides the first attempt to examine the impact of ripple current through immediate measurements on a single cell test. After cycling for hours at three frequencies, each polarization and impedance curve is obtained and compared with those of a fuel cell. Through experimental results, it can be absolutely concluded that low frequency ripple current leads to long-term degradation of a fuel cell. Three different PEMFC failures such as membrane dehydration, flooding and carbon monoxide (CO) poisoning that lead to an increase in the impedance magnitude at low frequencies are simply introduced.

• Korean Journal of Pharmacognosy
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• v.30 no.3
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• pp.275-279
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• 1999

The solvent extracts from Aloe arborescens and Aloe vera were randomly screened for inhibitory effects on the growth of tumor cell lines. In case of Aloe vera extracts, butyl alcohol extract and ethyl alcohol extract showed antitumor activity at $100\;{\mu}g/ml$ on lung cell lines(A427, Sk-mes-1, Calu-3 and 3LL). In Aloe arborescens extracts, butyl alcohol extract and ethyl alcohol extract exerted high activity at $100\;{\mu}g/ml$ on breast cell line(Hs-578T) and lung cell line(Sk-mes-1), respectively. The solvent extracts from Aloe vera exerted antitumor activity broadly on various tumor cell lines. In contract, the solvent extracts from Aloe arborescens exerted specific antitumoricity on a few tumor cell lines.

• Korean Journal of Oriental Medicine
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• v.11 no.2
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• pp.113-140
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• 2005

1. 백렴 추출물은 부분적으로 종양세포인 HT1080, Hep G2, MCF-7 cell에 대해 세포독성을 보였으나, 섬유세포인 7250 cells과 종양세포인 CT-26 cells에서는 세포독성은 나타나지 않았다. 2. 백렴 추출물은 macrophage에서 생산되는 NO production을 부분적으로 증가시켰다. 3. 백렴 추출물은 macrophage 활성화와 관련 있는 IL-1과 iNOS의 유전자 발현을 증가시켰다. 4. 백렴 추출물은 NK cell의 cytotoxicity를 활성화시켰다. 5. 백렴 추출물은 NK cell 활성화와 관련있는 IL-1, IL-4, IL-10, IL-12, iNOS, IFN-${\gamma}$, TNF-${\alpha}$ 의 유전자 발현을 증가시켰다. 6. 백렴 추출물은 마우스의 비장세포에서 IL-10, IFN-${\gamma}$, TNF-${\alpha}$ 의 단백질 발현을 증가시켰다. 7. 백렴 추출물은 CT-26 cell에 의한 pulmonary colony를 대조군에 비해 유의성 있게 억제시켰다. 이상의 결과로 백렴 추출물은 macrophage와 NK cell의 활성화를 통해 면역 조절과 항암제로서의 유용성이 기대된다.

• Molecules and Cells
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• v.43 no.6
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• pp.551-571
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• 2020

Nuclear receptor-related 1 (Nurr1) protein has been identified as an obligatory transcription factor in midbrain dopaminergic neurogenesis, but the global set of human NURR1 target genes remains unexplored. Here, we identified direct gene targets of NURR1 by analyzing genome-wide differential expression of NURR1 together with NURR1 consensus sites in three human neural stem cell (hNSC) lines. Microarray data were validated by quantitative PCR in hNSCs and mouse embryonic brains and through comparison to published human data, including genome-wide association study hits and the BioGPS gene expression atlas. Our analysis identified ~40 NURR1 direct target genes, many of them involved in essential protein modules such as synapse formation, neuronal cell migration during brain development, and cell cycle progression and DNA replication. Specifically, expression of genes related to synapse formation and neuronal cell migration correlated tightly with NURR1 expression, whereas cell cycle progression correlated negatively with it, precisely recapitulating midbrain dopaminergic development. Overall, this systematic examination of NURR1-controlled regulatory networks provides important insights into this protein's biological functions in dopamine-based neurogenesis.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.151.2-151
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• 1996

No Abstract, See Full Text

• Fibers and Polymers
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• v.2 no.2
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• pp.64-70
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• 2001

A three-dimensional, porous collagen/chitosan complex sponge was prepared to closely simulate basic extracellular matrix (ECM) constitutes, collagen and glycosaminoglycan. The complex sponge was prepared by a lyophilization method and had the regular network with highly porous structure, suitable for cell adhesion and growth. The pores were well interconnected, and their distribution was fairly homogeneous. The complex sponge was crosslinked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to increase its boilogical stability and enhance its mechanical properties. The crosslinking medium has a great effect on the inner structure of the sponge. The homogeneous, porous structure of the sponge was remarkably collapsed in an aqueous crosslinking medium. However, the morphology of the sponge remained almost intact in a water/ethanol mixture crosslinking milieu. Mechanical properties of the collagen/chitosan sponge were significantly enhanced by EDC-mediated crosslinking. The potential of the sponge as a scaffold for tissue engineering was investigated using a Chinese hamster ovary cell (CHO-K1) line.

• Journal of the Korean Electrochemical Society
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• v.3 no.4
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• pp.219-223
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• 2000

All-solid state lithium rechargeable thin film batteries were fabricated with the configuration of$Cu_{0.5}V_2O_5/Lipon/Li$ using sequential thin film techniques. Copper vanadium oxide thin films and Lipon thin films were prepared by DC reactive dual source magnetron sputtering and RF magnetron sputtering, respectively. According to XRD analysis, we found out that copper vanadium oxide thin films were amorphous. The electrochemical behaviour of them was examined in half cell system using EC : DMC(1:1 in IM $LiPF_5$) liquid electrolyte. The ionic conductivity of Lipon thin film was $1.02\times10^{-6}S/cm$ at $25^{\circ}C$ and $Cu_{0.5}V_2O_5/Lipon/Li$ cell showed that the discharge capacity was about $50{\mu}Ah/cm^2{\mu}m$ beyond 500cyc1es.