• IMMUNE NETWORK
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• 제3권1호
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• pp.29-37
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• 2003

Background: CC chemokine receptor (CCR) 7 and cognate CCR7 ligands, CCL21 (formerly secondary lymphoid tissue chemokine [SLC]) and CCL19 (formerly Epstein-Barr virus-induced molecule 1 ligand chemokine [ELC]), were known to establish microenvironment for the initiation of immune responses in secondary lymphoid tissue. As described previously, coadministration of DNA vaccine with CCR7 ligand-encoding plasmid DNA elicited enhanced humoral and cellular immunity via increasing the number of dendritic cells (DC) in secondary lymphoid tissue. The author hypothesized here that CCR7 ligand DNA could effectively expand memory CD4+ T cells to protect from viral infection likely via increasing DC number. Methods: To evaluate the effect of CCR7 ligand DNA on the expansion of memory CD4+ T cells, DO11.10.BALB/c transgenic (Tg)-mice, which have highly frequent ovalbumin $(OVA)_{323-339}$ peptide-specific CD4+ T cells, were used. Tg-mice were previously injected with CCR7 ligand DNA, then immunized with $OVA_{323-339}$ peptide plus complete Freund's adjuvant. Subsequently, memory CD4+ T cells in peripheral blood lymphocytes (PBL) were analyzed by FACS analysis for memory phenotype ($CD44^{high}$ and CD62 $L^{low}$) at memory stage. Memory CD4+ T cells recruited into inflammatory site induced with OVA-expressing virus were also analyzed. Finally, the protective efficacy against viral infection was evaluated. Results: CCR7 ligand DNA-treated Tg-mice showed more expanded $CD44^{high}$ memory CD4+ T cells in PBL than control vector-treated animals. The increased number of memory CD4+ T cells recruited into inflammatory site was also observed in CCR7 ligand DNA-treated Tg-mice. Such effectively expanded memory CD4+ T cell population increased the protective immunity against virulent viral infection. Conclusion: These results document that CCR7 and its cognate ligands play an important role in intracellular infection through establishing optimal memory T cell. Moreover, CCR7 ligand could be useful as modulator in DNA vaccination against viral infection as well as cancer.

• IMMUNE NETWORK
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• 제3권1호
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• pp.69-77
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• 2003

Background: Celecoxib, a COX-2 specific inhibitor, has recently been used for the treatment of rheumatoid arthritis. However, the molecular and cellular mechanisms of celecoxib against RA inflammation remain to be defined. To elucidate the action mechanism of celecoxib on inflammatory cells, we investigated the effect of celecoxib on the production of two important mediators of inflammation, nitric oxide and PGE2 Methods: RAW 264.7 cells stimulated with LPS were preincubated with various concentrations of celecoxib (from $10^{-8}$ to $10^{-5}$ M) and $10{\mu}M$ hydrocortisone, respectively. The production of NO and PGE2, the end products of iNOS and COX-2 genes, were estimated in culture supernatants by Greiss method and EIA, respectively. The expression of iNOS gene, COX-2 gene, $NF-{\kappa}B$, and $I-{\kappa}B$ were determined by RT-PCR and western blot analysis. Results: Celecoxib and hydrocortisone inhibited the production of NO and PGE2 in dose dependent manner, when RAW 264.7 cells were stimulated with LPS. The expression of iNOS was also down-regulated by celecoxib and hydrocortisone. Interestingly, COX-2 gene differentially expressed according to the dose of celecoxib, a decrease with lower dose ($10^{-8}$ M) but an increase with higher dose ($10^{-5}$ M). $NF-{\kappa}B$ binding activity was decreased by lower dose of celecoxib, whereas was not affected by higher dose of it. The expression of $I-{\kappa}B$ was suppressed by higher dose of celecoxib. Conclusion: The celecoxib strongly suppressed the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. The decrease of NO seems to be linked to the inhibition of iNOS by celecoxib. The lower and higher dose of celecoxib differentially regulated the COX-2 expression and $NF-{\kappa}B$ activity.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제11권1호
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• pp.101-116
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• 1989

Proplast and Porous Polyethylene which have porous structures as low-modulus polymers have been recently used in maxillofacial plastic and reconstructive surgery. The purpose of this study was to compare the response of adajacent tissue, new bone formation and stability after augmentation by differen methods of subperiosteal graft using proplast and purous polythylene in rabbit mandible. The augmentation procedure was carried out by dividing into two groups, A and B. A group consisted of subperiosteal graft on the cortex, and the other B group was made up only graft following artificial decortication in the mandibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and light microscopic examination. The samples extracted at the 6th postgrafting week were also used for biometric testing and scanning electron microscopic examination. The results obtained from this study were as follows : 1. Macroscopically, infection of graft site, deformation and migration of graft material were not observed in all experimental groups. 2. B group showed more rapid and increased bone formation and the greater stability than A group, and tissue response was similar to each other. 3. In the tissue response, macrophages and cellular infiltrations were observed in Proplast group, but few in PHDPE group. 4. In bone formation of A group, Proplast group showed no bone formation until the 8th week, but PHDPE group showed small quantity of osteoid tissue from the 2nd week and appositional bone growth with new bone formation at the 8th week. 5. In bone formation of B group, both Proplast and PHDPE group showed bone formation, but PHDPE group showed more rapid and larger bone formation. 6. In pattern of bone formation, Proplast group mainly showed appositional bone growth pattern connected with graft site. On the other hand, PHDPE group showed mixed pattern of new bone formation in the pore connective tissue with appositional bone growth from graff site. 7. The maximum mean values of shear stress were serially $111.3gf/mm^{2}$ in PHDPE of B group, $84.8gf/mm^{2}$ in PHDPE of A group, $32.9gf/mm^{2}$ in Proplast B group, and $15.7gf/mm^{2}$ in Proplast of A group. From above results, It was suggested that the capacity of bone formation and stability between bone and graft material were dependent on the pore size and structure of graft material itself, the state of graft site and tissue response.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권3호
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• pp.248-258
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• 2005

The challenging task of classifying the fibro-osseous(FO) lesions has been previously attempted but only in the past 15 years has the entire spectrum of diversity been appreciated. For the clinicians, it is hard to clearly diagnose the lesions before operations. The purpose of this study was to review the literature about fibro-osseous lesions of the jaws and to analyse our clinical cases. As the results of the review of clinical features, radiography and histopathologic findings of sixteen cases of fibro-osseous lesions, we could elucidate diagnostic aids for treatment of benign FO lesion in jaws. Six patients involving fibrous dysplasia complained the facial swelling and facial asymmetry. The radiographic features of the lesions showed ground-glass radiopacity mostly and the histologic findings showed typically Chinese character-shaped trabeculae without osteoblastic rimming in the fibrous stroma. Six patients with ossifying fibroma were notified as swollen buccal cheek state. Their radiographic findings showed cortical expanded radiolucent lesion with sclerotic defined border, which was contrast to the normal adjacent bone. The lesions showed variant radiolucent lesions. Histological findings were revealed as cellular fibrous stroma with woven bones, variable patterns of calcifications. Three patients with cemental dysplasia didn't have specific complaints. Well circumscribed radiopaque lesions on mandibular molar area were observed. Cementum-like ossicles with fibrous stroma were found on microscopic findings. A osteoblastoma case with jaw pain was found. The radiographic feature was a mottled, dense radiopacity with osteolytic border on mandibular molar area. Under microscopy trabecule of osteoid with vascular network were predominantly found. Numerous osteoblast cells with woven bone were found. These clinical, radiographic and microscopic findings of benign fibrous-osseous lesions would suggest diagnostic criteria for each entity of FO lesions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권1호
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• pp.41-51
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• 2008

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor which compromises about 6$\sim$8% of all tumors followed by the adenoid cystic carcinoma (ACC) and adenocarcinoma. Most deaths from salivary carcinomas are caused by recurrent or metastatic lesions that are resistant to conventional therapy. Therefore, knowledge of cellular properties and tumor-host interactions that influence the vascular metastasis is important for the design of more effective therapy of salivary carcinomas. Neoangiogenesis is essential for tumor growth, which is postulated to be fundamentally dependent on the induction of stromal neovascularization. However, how neovascularization takes place in live tissue has not been fully established, especially in recruitment and differentiation of endothelial cells in the salivary gland tumors. Vascular endothelial growth factor (VEGF) is a heparin-binding, dimeric polypeptide growth factor known to exert its mitogenic activity specifically on endothelial cells. VEGF has been shown th be directly involved in angiogenesis, which in essential for the pathogenesis of many solid tumors. von Willebrand factor (vWF) is a large multimeric protein synthesized by megakaryocytes and endothelial cells that enable platelets to adhere to exposed subendothelium and, as well, to respond to changes in the blood flow. Recent studies suggest that increased levels of vWF correlate with progression of disease, metastasis, or survival time and thus may have a prognostic significance. vWF is explained as an acute phase proteins which is increased in cancer or as a result of increased endothelial cell synthesis associated with tumor-induced angiogenesis. Due to adhesive properties of vWF, its increased concentrations may also contribute metastasis of tumor. In this study, we determined the mRNA expression of VEGF and vWF in salivary ACC, MEC and pleomorphic adenoma by in situ hybridization. As a result, stronger expression of VEGF and vWF was seen in salivary ACC and MEC which has more invasive nature than the salivary benign tumor.

• 대한치과교정학회지
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• 제27권6호
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• pp.955-961
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• 1997

흡연의 주성분중의 하나인 니코틴은 인체내에 다양한 전신적 및 국소적인 질환의 원인으로 보고 되어지고 있다. 전신적인 질환에 있어 특히, 호흡기와 순환기 조직세포에 대한 세포분열효과가 많은 연구의 초점이 되어왔으며, 국소적인 효과에 대한 연구에서는 조직파괴나 치료후 치유지연에 대해 보고하고 있다. Platelet-Derived Growth Factor(PDGF)와 Insulin-like Growth Factor(IGF)는 치주인대세포의 세포분열을 촉진하는 주요 성장인자로 알려져있다. 본 연구의 목적은 니코틴이 사람의 치주인대세포에 미치는 세포분열효과를 알아보기 위하여 니코틴 처리된 치주인대세포로부터 추출한 PDGF-${\alpha}\;and\;{\beta}$ receptor 및 IGF-l 수용기의 mRNA변화를 Northern분석을 이용해 확인해 보고자 함이다. 실험군은 각기 다른 농도의 니코틴(100ng/ml, 1000mg/ml)과 배양액내 혈청농도($1\%,\;10\%$)로 나누었으며 이를 각각 니코틴 처리 시간에 따라 분류하였다. 본연구의 결과로 $10\%$ 혈청의 배양액과 100ng/ml 니코틴 농도군에서 모든 성장인자 수용체의 mRNA가 증가됨을 보였으며 이는 흡연자의 체내 축적 가능한 니코틴 농도에서 치주인대세포의 세포분열을 촉진한다는 추측을 가능케 한다.

• Molecules and Cells
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• 제25권1호
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• pp.55-63
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• 2008

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the selective death of motor neurons. Mutations in the SOD1 gene are responsible for a familial form of ALS (FALS). Although many studies suggest that mutant SOD1 proteins are cytotoxic, the mechanism is not fully understood. To investigate the role of mutant SOD1 in FALS, human SOD1 genes were fused with a PEP-1 peptide in a bacterial expression vector to produce in-frame PEP-1-SOD fusion proteins (wild type and mutants). The expressed and purified PEP-1-SOD fusion proteins were efficiently transduced into neuronal cells. Neurones harboring the A4V, G93A, G85R, and D90A mutants of PEP-1-SOD were more vulnerable to oxidative stress induced by paraquat than those harboring wild-type proteins. Moreover, neurones harboring the mutant SOD proteins had lower heat shock protein (Hsp) expression levels than those harboring wild-type SOD. The effects of the transduced SOD1 fusion proteins may provide an explanation for the association of SOD1 with FALS, and Hsps could be candidate agents for the treatment of ALS.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.103-111
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• 2011

Purpose: Choukroun's platelet-rich-fibrin (PRF) is composed of platelets, white blood cells and fibrin matrix. It does not induce enough bone formation by itself but it can improve bone formation with calcium. Silk fibroin does not cause inflammatory reactions because it is bio-compatible and degradable. The purpose of this study was to exam the bone formation when a combination of Choukroun's PRF and silk fibroin was used. Methods: In this study, cell reactions to silk powder with differing molecular weights was first tested to select the appropriate silk powder. Then we applied these bone graft materials on defects of skull and in a peri-implant bony defect model in New Zealand rabbits. The results between the experimental and control s (non-grafted) group were analyzed. Results: The small sized silk fibroin powder showed increased cellular proliferation for bone-regeneration. There was no statistically significant difference between the experimental group and the control group at 6 weeks, but more new bone formation was observed in the combination graft group at 12 weeks (P<0.05). And in the dental implant model, the combination bone graft group showed much improved torque test results, which was statistically significant. Histomorphometric analysis showed more regenerated cortical bone and a higher mean bone to implant in the experimental group. Both were statistically significant. Conclusion: The combination graft of Choukroun's platelet-rich-fibrin (PRF) and silk fibroin powder can successfully restore the bony defects in a skull defected model and a peri-implant bony defects model.

• 한국전자파학회논문지
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• 제24권5호
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• pp.534-540
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• 2013

휴대전화의 이용이 증가하면서, 손에 미치는 전자파의 영향에 대한 관심이 증가하고 있다. IEC TC106에서도 휴대전화의 전자파 인체 노출량 평가 방법 표준에 손 영향을 반영하기 위하여 국제적인 교류 연구가 활발하게 진행되고 있다. 현재 상용화된 손 팬텀은 평균 서양인 손을 이용하고 있을 뿐만 아니라, 한 가지 형태의 파지(把持)만 가능하기 때문에, SAR 측정 결과에 대한 분석에 제한이 많은 실정이다. 손의 영향을 제대로 분석하기 위해서는 다양한 형태의 파지가 가능한 손 팬텀이 필요하다. 또한, 국내 환경에 맞는 손 팬텀의 개발이 필수적이다. 본 논문에서는 다양한 형태의 파지가 가능한 835 MHz 대역과 1,800 MHz 대역의 한국인의 젤리형 손 팬텀을 제작하였다. 제작된 손 팬텀의 전기적 특성은 비유전율과 도전율이 CTIA(미국이동통신산업협회) 권고 기준 값의 ${\pm}10%$이내로서, CTIA에서 제시하는 오차 기준(${\pm}20%$)보다 더 우수한 특성을 나타냈다. 또한, 손 팬텀의 3D CAD(3차원 컴퓨터 이용 설계) 파일을 개발하여 손에 의한 SAR 영향 분석을 위한 시뮬레이션에서 활용할 수 있도록 하였다. 본 연구를 통해 제작된 젤리형 손 팬텀과 3D 파일은 휴대 전화의 손 영향에 대한 연구에 유용하게 이용될 수 있을 것으로 본다.

• 한국생활과학회지
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• 제9권1호
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• pp.137-152
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• 2000

The purpose of this study was to investigate the disposition of adolescents in their ornament wearing pattern associate with their life style and clothing behavior. The subject of this study consists of 345 middle and high school girls living in Chung-Nam Province and Taejon Metropolitan City. SPSS/PC+ program was utilized to calculated frequency(N), mean value(M) and standard deviation(SD) for statistical analysis. Differences among the populations were examined through f test, ANOVA. The results of this study reveals that the ornaments wearing patterns are significantly different according to their life style and clothing behavior as follows: 1. Correlation between the wear of ornaments and the life style: School girls who pursue the modernistic life style prefer the fashionable ornaments (e.g. sunglasses) and they are always in contact with the latest information. On the contrary, school girls who pursue the practical life style emphasize on the practical use when they purchase the ornaments, e.g. umbrella. School girls having romantic or passive nature have a preference for the brand name and brand image of the ornaments and they in general would like to buy ornaments such as the bracelets. 2. Correlation between the wear of ornaments and the clothing behavior: School girls having sympathetic nature and being deeply interested in clothing put a stress on the latest fashion of the ornaments. They usually want to buy fashionable ornaments such as the cellular phone, beeper and sunglasses. Subjects who estimate themselves by their garments are sensitive to the price of the ornaments while aesthetes emphasize the brand image of the ornaments. Chaste school girls put their emphasis on the quality of the ornaments and they most want to have functional hair bands. Following suggestions can be made based on the discussions above: It is necessary for us to have correct understanding about the correlation between the ornaments and clothing of school girls in order to lead them to have appropriate clothing behavior. Furthermore, it is required to construct a bridge linking a course of study to rational habits guidance which will provide us more appropriate tools for clothing behavior guidance.