• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.503-513
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• 1997

This study was undertaken to investigate the effect of oxygen tension on the activity and function of the cells derived from human periodontal ligament by measuring cell activity, total protein synthesis, collagen synthesis, $IL-1{\beta},\;IL-6,\;TNF-{\alpha}$ Human periodontal ligament fibroblasts were collected from premolars extracted for orthodontic treatment and incubated in the environment of $37^{\circ}C,\;5\%\;CO_2,\100\%$ humidity. After the fifth to sixth passage they were used for the experiment. Gaspack system to which $0.2{\mu}m$ Millipore filter was attached was connected to mixed-gas tanks. The mixed gases were composed of $10\%\;O_2,\;5\%\;CO_2,\;85\%\;N_2$ in hyoxic group or $90\%\;O_2,\;5\%\;CO_2,\;5\%\;N_2$ in hyperoxic group and $5\%\;CO_2,\;95\%$ air for control. After incubation in $37^{\circ}C$ for 2, 4, 6 days, cell activity was determined by tetrazolium(MTT) assay and total protein synthesis was assayed using sulforhodamine B(SRB). And measurement of 4-hydroxyproline was performed to assess collagen synthesis md $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ were measured by enzymeimmunoassay. The results were as follows. 1. The cell activity and total protein synthesis in hypoxic group were a little higher than or almost the same with those in control group. 2. In hyperoxic group, the cell activity was lower than that in control group and total protein synthesis was decreased. 3. Collagen synthesis was significantly decreased initially in both hypoxic and hyperoxic group and increased nearly to the level of control group as the duration of cell incubation was longer 4. As a result of enzymeimmunoassay, the amount of cytokines was $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ in order. 5. $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ were increased more rapidly in both hypoxic and hyperoxic group than in control group as the duration of cell incubation was longer. 6. There were more $IL-6\;and\;TNF-{\alpha}$ in hyperoxic group than in control group after 6 days, and there were more $IL-6\;and\;TNF-{\alpha}$ after 6 days than after 2 or 4 days in hyperoxic group. These results suggested that oxygen tension might modulate the production of extracellular matrix and cytokines in the cells derived from human periodontal ligament.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.747-753
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• 2003

면역글로불린의 Fc 부분에 대한 수용기인 $Fc{\gamma}R$는 세균에 대한 인식, 결합과 포식작용과정에서 중요한 역할을 한다. 이 $Fc{\gamma}R$에서 $Fc{\gamma}R$IIa, $Fc{\gamma}R$IIIa, $Fc{\gamma}R$IIIb의 유전자 다형성이 치의학 분야에서 연구되고 있다. $Fc{\gamma}R$IIa에서는 두 번째 세포외 면역글로불린 유사 영역의 131번째 아미노산에서 아르기닌($Fc{\gamma}R$IIa-R131) 혹은 히스티딘($Fc{\gamma}R$IIa-H131)을 갖고 있으며, $Fc{\gamma}R$IIIa에서는 두번째 세포외 영역의 158번째 아미노산이 발린($Fc{\gamma}R$IIIa-158V) 혹은 페닐알라닌($Fc{\gamma}R$IIIa-158F)을 갖고 있다. $Fc{\gamma}R$IIIb에서는 첫 번째 세포외 면역글로불린 유사영역의 4개의 아미노산의 유전자 다형성으로 인해서 $Fc{\gamma}R$IIIb-NA1과 $Fc{\gamma}R$IIIb-NA2의 두가지 유전자 다형성을 보이고 있다. 이번 연구는 치주적으로 건강한 한국인에서 $Fc{\gamma}R$IIa, $Fc{\gamma}R$IIIa, $Fc{\gamma}R$IIIb에 대한 유전자형의 분포를 조사하고자 한 것으로 서울대학교 치과병원에 근무하는 치과의사, 치과위생사, 간호조무사 및 서울대학교 치과대학 4학년 학생 중 치주낭 깊이와 부착소실이 4mm 이하인 치주적으로 건강한 한국인 65명을 대상으로 하였다. $Fc{\gamma}R$IIa, $Fc{\gamma}R$IIIa, $Fc{\gamma}R$IIIb의 유전자 다형성은 분리한 DNA에 각 대립유전자에 특이성을 지닌 primer를 넣고 PCR(polymerase Chain Reaction)법을 이용하여 증폭시킨후 전기영동법을 이용하여 각 대립유전자의 존재를 확인함으로써 결정하였다. $Fc{\gamma}R$IIa의 유전자 다형성은 R/R131, R/H131, H/H131의 유전자형에 대하여 각각 7.7%, 38.5%, 53.8%의 분포를 보였으며, $Fc{\gamma}R$IIIa의 158V/V, 158V/F, 158F/F 유전자형에 대하여 각각 7.7%, 35.4%, 56.9%의 분포를 보였다. 또한 $Fc{\gamma}R$IIIb의 NA1/NA1, NA1/NA2, NA2/NA2 유전자형은 각각 33.9%, 53.8%, 12.3%의 분포를 보였다. 이를 바탕으로 각 대립유전자의 발생빈도 계산한 결과 $Fc{\gamma}R$IIa의 R131과 H131이 26.9% 73.1%로 나타났으며, $Fc{\gamma}R$IIIa의 158V, 158F의 유전자형이 25.4%, 74.6%로 나타났다. $Fc{\gamma}R$IIIb의 NA1, NA2 유전자형의 발생빈도는 60.8%, 29.2%로 나타났다. 이번 연구는 치주적으로 건강한 한국인에서의 $Fc{\gamma}R$IIa, $Fc{\gamma}R$IIIa, $Fc{\gamma}R$IIIb에 대한 유전자형의 분포를 조사한 것으로, 이후 치주질환자의 유전자형 분포와의 비교로 치주질환과 $Fc{\gamma}R$IIa, $Fc{\gamma}R$IIIa, $Fc{\gamma}R$IIIb의 유전자다형성과의 관련성에 관한 추가적인 연구가 필요할 것으로 여겨진다.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.361-374
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• 1999

Intraoral filled type of orthodontic appliance can cause reversible or irreversible damages such as gingivitis, periodontitis, enamel decalcification, dental caries, root resorption, and pulpal changes. Such adverse effects are brought by increase in dental plaque as well as oral flora. Such an increase causes gingival inflammation and enamel decalcification. The purpose of this study is to get klowledge on initial changes in dental plaque, gingivitis, and enamel decalcification after bonding fixed orthodontic appliances according to time flow, gender, and sides(right/left) of premolar region. For control group, 48 students of dental college, Yonsei university(26 males, 22 females) were chosen; for experimental group, 73 orthodontic patients(36 males, 37 females) who will be treated with fixed appliances were chosen. All the subjects had no systemic disease, juvenile periodontitis and all the females had passed their ,menarche. Tooth brushing instruction was given to all the subjects prior to the experiment. For control group, plaque index, gingival index, and decalcification index were measured twice at 3 weeks interval ; for experimental group, the same was done prior to, 3, 6, 9 weeks after bonding fixed appliances. The following results were obtained: 1. In plaque index 3 weeks after placement of appliances, and it showed gradual increase afterwards. 2. In gingival index3 weeks after placement of appliances, and afterwards it showed increase at a faster rate than plaque index. 3. Enamel decalcification began to show between 3 and 6 weeks after bonding fixed appliances. Decalcification index began to increase 6 weeks after appliance placement, but there was no statistical significance. 4. When the comparison was made between two sides of premolar region, the right side showed greater index in plaque and gingival index of experimental group.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.16-22
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• 1993

Background: The Microbicidal and cytotoxic activities of neutrophils are to a large extent dependent on a burst of oxidative metabolism which generates superoxide anion, hydrogen peroxide, and other reactive products of oxygen. The respiratory burst of PMN is initiated by intracellular calcium mobilization that follows immune or particular stimulation and is very sensitive to modulation by c-AMP or adenosine. Despite its antagonism against adenosine, earlier study has demonstrated potent theophylline inhibition of the PMN respiratory burst at variable ranges of blood concentrations of theophylline in the healthy normal volunteers and in the septic animals pretreated or early post-treated with aminophylline (AMPH) or pentoxifylline. However it is unclear whether theophylline inhibits the superoxide generation or not in the established human sepsis caused by acute pneumonia, as taking into consideration of the fact that full activation of neutrophils have occurred within minutes after the septic insult in the animal experiments. Methods: We measured the $O_2$ generation of peripheral arterial neutrophils obtained from 11 human septic subjects caused by acute pneumonia before and 1 hour after completion of continuous AMPH infusion. Patients were identified and studied within 48 hour of admission. All subjects were administered an intravenous loading and maintenance dose of AMPH. The generation of $O_2$ was measured at a discrete time point (60 min) by the reduction of ferricytochrome c.PMA (10 ${\mu}g/ml$) was used as a stimulating agent. PMNs were isolated at a concentration of $2{\times}10^6$ cells/ml. The arterial oxygen tension, blood pressure and heart rates were also checked to evaluate the systemic effects of AMPH in the acute pneumonia. Results: The mean serum concentration of AMPH at 60 minutes was $8.8{\pm}0.6{\mu}g/ml$. Sixty minutes after AMPH infusion the generatition of $O_2$ was decreased from $0.076{\pm}0.034$ to $0.013{\pm}0.004$(OD) (p<0.05) and from $0.177{\pm}0.044$ to $0.095{\pm}0.042$(OD) (p<0.01) in the resting and stimulated PMNs respectively. $PaO_2$ was not changed after AMPH infusion. Conclusion: AMPH may compromise host defense by significant inhibition of neutrophil release of superoxide anion and it had no effect on improving $PaO_2$ in the acute pneumonia.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.569-583
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• 2004

The rock properties of the West pagoda in the Gameunsaji temple site are composed mainly of dark grey porphyritic granodiorite with medium grained equigranular texture and developed with small numerous dioritic xenoliths. These xenoliths occurred with small holes due to different weathering processes. As a weathering results, the rock properties of this pagoda occur wholly softened to physical hardness because of a complex result of petrological, meteorological and biological causes. Southeastern part of the pagoda deteriorated seriously that the surface of rock blocks showed partially exfoliations, fractures, open cavities in course of granular decomposition of minerals, sea water spray and crystallization of salt from the eastern coast. The Joint between blocks has small or large fracture cross each other, contaminated and corrupted for inserting with concrete, cement mortar, rock fragments and iron plates, and partially accelerated coloration and fractures. There are serious contamination materials of algae, fungus, lichen and bryophytes on the margin and the surface on the roof stone of the pagoda, so it'll require conservation treatment biochemically for releasing vegetation inhabiting on the surface and the discontinuous plane of the blocks because of adding the weathering activity of stones and growing weeds naturally by soil processing on the fissure zone. Consisting rock for the conservation and restoration of the pagoda would be careful choice of new rock properties and epoxy to reinforce for the deterioration surfaces. For the attenuation of secondary contamination and surface humidity, the possible conservation treatments are needed.

• Journal of Life Science
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• v.31 no.3
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• pp.330-337
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• 2021

This study was conducted to investigate the potential of Stewartia koreana as oral healthcare materials. The antibacterial activity of ethanol extracts from leaves and branches of S. koreana against oral bacteria was confirmed. The leaf and branch extracts (1 mg/disc) showed antibacterial activity against P. gingivalis only among several tested oral bacteria. The leaf extracts showed higher antibacterial activity, with values similar to those of chlorhexidine, which was used as a positive control. The MIC of the leaf extract against P. gingivalis was 0.4 mg/ml and showed bacteriostatic action. The inhibitory effects of the extract on biofilm formation and on gene expression related to biofilm formation by P. gingivalis were determined by biofilm biomass staining, scanning electron microscopy (SEM), and qRT-PCR analysis. The biofilm production rate and cell growth of P. gingivalis in the cultures treated with 0.2-2.0 mg/ml of S. koreana leaf extracts were significantly decreased in a concentration-dependent manner. The inhibitory effect on the formation of P. gingivalis biofilms at concentrations of 1 mg/ml was confirmed by SEM. The qRT-PCR analysis showed concentration-dependent suppression of the fimA and fimB gene expression associated with fimbriae formation in the cultures treated with 0.2-2.0 mg/ml S. koreana leaf extract. These results support the conclusion that S. koreana leaf extracts can be used as oral healthcare materials derived from natural materials, as demonstrated by the antibacterial action and inhibition of biofilm formation of P. gingivalis.