• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.579-590
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• 2006

1. 연구배경 교원질 분해작용을 하는 호중구의 세포질 효소인 기질금속단백분해효소-8은 치주질환, 류마티스 관절염, 그리고 궤양결장염과 같은 염증성 질환에서 농도가 증가한다고 알려져 있다. 최근에는 A. actinomycetemcomitans의 leukotoxin이 사람호중구에서 기질금속단백분해효소-8의 분비를 유도하는 것이 보고되었다. 이 연구의 목적은 선천면역 체계에서 세포표면 항원무리14, Toll-like 수용기, 그리고 $NF-{\kappa}$ B경로를 통하여 A. actinomycetemcomitans의 지질다당질로 유도된 기질금속단백분해효소-8의 분비 여부와 세포기전을 알아보고자 하였다. 2. 연구재료 및 방법 건강한 개인 제공자(남자 13명, 여자 3명)로부터 얻은 개개인의 20ml 말초혈액을 제조사의 지침에 따라 호중구를 추출한 후 항세포표면 항원무리14와 함께 $4^{\circ}C$에서 30분간 전배양 한 후, $37^{\circ}C$에서 9시간 동안 배양시켰다. 추출한 호중구에 Toll-like 수용기 억제제 또는 $NF-{\kappa}$ B억제제인 TPCK를 첨가한 후 $37^{\circ}C$에서 1시간 동안 전배양하고 $37^{\circ}C$에서 9시간 동안 배양시켰다. 호중구에 세포뼈대 억제제인 cholchicine, nocodazole, demecolcine, 그리고 cytochalasin B를 A. actinomycetemcomitans의 지질다당질과 함께 $37^{\circ}C$에서 9시간 동안 배양시켰다. 기질금속단백분해효소-8 분비량은 효소면역측정법을 통해 결정하였다. 통계처리는 일원배치 분산분석법을 이용하였다(p<0.05). 3. 결과 A. actinomycetemcomitans 지질다당질은 기질금속단백분해효소-8의 분비를 증가시켰다. 기질금속단백분해효소-8의 분비는 항세포표면 항원무리14에 의해서 억제되었지만, 항 Toll-like 수용기2, 항 Toll-like 수용기4 항체는 억제시키지 못했다. $NF-{\kappa}$ B 억제제는 A. actinomycetemcomitans의 지질다당질로 유도된 $NF-{\kappa}$ B 결합 활성도와 기질금속단백분해효소-8 분비를 억제하였다. 미세섬유 중합반응 억제제는 A. actinomycetemcomitans의 지질다당질로 유도된 기질금속단백분해효소-8의 분비를 억제시켰으나, 미세관 중합반응억제제는 억제시키지 못했다. 4. 결론 위의 연구결과를 종합하여 볼 때, 기질금속단백분해효소-8은 A. actinomycetemcomitans의 지질다당질로 유도되며, 세포표면 항원무리-$NF-{\kappa}$ B 경로를 통하여 분비되고, 이 분비 과정은 미세섬유 계통이 관여하는 것으로 보인다.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.1-17
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• 1997

Tetracycline is known to be effective in eliminating periodontopathogens and have collagenolytic activity. This study was performed to observe the desorption kinetics and structural changes of tetracycline-treated barrier membranes for guided tissue regeneration. Four kinds of barrier membranes were tested : $Tefgen^{(R)}$(American Custom Medical, USA) and $Gore-Tex^{(R)}$(W.L. Gore & Associates Inc., USA) as nonresorbable membranes ; Resolut(polyglycolide & polylactide copolymer, W.L. Gore & Associates Inc., USA) and $Biomend^{(R)}$(collagen, Collatec Co., USA) as resorbable membranes. The membranes were cut into discs(diameter : 4mm) and were immersed in 5% tridodecylmethylammonium chloride(TIMAC) ethanol and air-dried. The membrane discs were absorbed with $100{\mu}g/ml tetracycline solution(pH8) for one minute and dried. For desorption kinetics, TC treated discs were immersed in phosphate buffered saline solution (PBS, pH 7.4). PBS was exchanged daily and TC concentration was measured by absorbance at 276nm on UV spectrophotometer. To measure remaining antibacterial activity, discs of 1 day to 4 weeks after desorption were placed on Mueller Hinton agar containing Bacillus cereus and incubated aerobically in $37^{\circ}C$ for twelve hours and the inhibition diameters were measured. To observe the structural change of membranes after TIMAC treatment or immersion in PBS, the membrane discs were examined under SEM. The results were as follows : 1. Total amounts of TC absorbed into membrane discs($0.7536mm^2$) were $2000{\mu}g$, $1800{\mu}g$, $2625{\mu}g$ and $2499{\mu}g$ for $Tefgen^{(R)}$, $Gore-Tex^{(R)}$, $Biomend^{(R)}$ and $Resolut^{(R)}$. 2. The concentration of TC released from barrier membrane discs was maintained over $4{\mu}g/ml$ until the fifth day in nonresorbable membranes and $Resolut^{(R)}$, but until the fourth day in $Biomend^{(R)}$, Until the ninth day in nonresorbable membranes and until the seventh day in resorbable membranes, the TC concentration was maintained over $1{mu}g/ml$. 3. The four membrane discs in the first day showed similar size of inhibition zone. One to four weeks later, the inhibition zone was much smaller in resorbable membrane discs than nonresorbable membrane discs. 4. Any structural change due to treatment of TIMAC was not observed on the nonresorbable membranes. $Resolut^{(R)}$ did not show any structural change except fibrillar loosening during immersion period, but Biomend showed destruction of membrane structure from the first week of immersion. This study indicates that tetracycline treated barrier membranes lead to the sustained release of tetracycline for over 7 days. This slow release pattern of tetracycline may contribute to the favorable clinical outcome of guided tissue regeneration.

• Macromolecular Research
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• 제10권3호
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• pp.158-167
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• 2002

In order to endow with new bioactive functionality from small intestine submucosa (SIS) powder as natural source to poly (L-lactide) (PLA) and poly (lactide-co-glycolide) (PLGA) synthetic biodegradable polymer, porous SIS/PLA and SIS/PLGA as natural/synthetic composite scaffolds were prepared by means of the solvent casting/salt leaching methods for the possibility of the application of tissue engineered bone and cartilage. A uniform distribution of good interconnected pores from the surface to core region was observed the pore size of 40~500 ${\mu}{\textrm}{m}$ independent with SIS amount using the solvent casting/salt leaching method. Porosities, specific pore areas as well as pore size distribution also were almost same. After the fabrication of SIS/PLA hybrid scaffolds, the wetting properties was greatly enhanced resulting in more uniform cell seeding and distribution. Five groups as PGA non-woven mesh without glutaraldehyde (GA) treatment, PLA scaffold without or with GA treatment, and SIS/PLA (Code No.3 ; 1 : 12 of salt content, (0.4 : 1 of SIS content, and 144 ${\mu}{\textrm}{m}$ of median pore size) without or with GA treatment were implanted into the back of nude mouse to observe the effect of SIS on the induction of cells proliferation by hematoxylin and eosin, and von Kossa staining for 8 weeks. It was observed that the effect of SIS/PLA scaffolds with GA treatment on bone induction are stronger than PLA scaffolds, that is to say, in the order of PLA/SIS scaffolds with GA treatment > PLA/SIS scaffolds without GA treatment > PGA nonwoven > PLA scaffolds only with GA treatment = PLA scaffolds only without GA treatment for the osteoinduction activity. The possible explanations are (1) many kinds of secreted, circulating, and extracellular matrix-bound growth factors from SIS to significantly affect critical processes of tissue development and differentiation, (2) the exposure of SIS to GA resulted in significantly calcification, and (3) peri-implant fibrosis due to covalent bonding between collagen molecule by crosslinking reaction. In conclusion, it seems that SIS plays an important role for bone induction in SIS/PLA scaffolds for the application of tissue engineering area.

• 대한의용생체공학회:의공학회지
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• 제32권3호
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• pp.218-229
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• 2011

Companding algorithms have been used to enhance speech recognition in noise for cochlea implant users. The efficiency of using companding for digital hearing aid users is not yet validated. The purpose of this study is to evaluate the performance of the companding for digital hearing aid users in the various hearing loss cases. Using HeLPS, a hearing loss simulator, two different sensorinerual hearing loss conditions were simulated; mild gently sloping hearing loss(HL1) and moderate to steeply sloping hearing loss(HL2). In addition, a non-linear compression was simulated to compensate for hearing loss using national acoustic laboratories-non-linear version 1(NAL-NL1) in HeLPS. In companding, the following four different companding strategies were used changing Q values(q1, q2) of pre-filter(F filter) and post filter(G filter). Firstly, five IEEE sentences which were presented with speech-shaped noise at different SNRs(0, 5, 10, 15 dB) were processed by the companding. Secondly, the processed signals were applied to HeLPS. For comparison, signals which were not processed by companding were also applied to HeLPS. For the processed signals, log-likelihood ratio(LLR) and cepstral distance(CEP) were measured for evaluation of speech quality. Also, fourteen normal hearing listeners performed speech reception threshold(SRT) test for evaluation of speech intelligibility. As a result of this study, the processed signals with the companding and NAL-NL1 have performed better than that with only NAL-NL1 in the sensorineural hearing loss conditions. Moreover, the higher ratio of Q values showed better scores in LLR and CEP. In the SRT test, the processed signals with companding(SRT = -13.33 dB SPL) showed significantly better speech perception in noise than those processed using only NAL-NL1(SRT = -11.56 dB SPL).

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.565-571
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• 2001

The purpose of this study is to determine if a relationship exists among osteoporosis, alveolar bone density and periodontal disease in postmenopausal osteoporotic women and postmenopausal healthy women. Twenty-two women were evaluated for this study. They were attending the postmenopausal clinic, Seoul National University Hospital and generally healthy except osteoporosis. They had experienced menopause not less than one year when we began to examine them. Bone densities of lumbar area(L2-L4) was determined by DEXA(LUNAR-expert Co,. U.S.A). We diagnosed osteoporosis when T-score was below -2.5 and healthy state when T-score was over -1. Osteoporotic(10 female), not hormone-treated group and healthy control group(12 female) were asked for their age, menopausal age, menopausal period and the number of remaining teeth and examined clinically for plaque index(PI), gingival index(GI), clinical attachment loss(CAL) on their 6 Ramfjord index teeth. Intraoral radiographs were taken in maxillary anterior zone. All films were equally exposed and developed. Each films was digitized and analysed using image processing software, Scion image. Alveolar bone regions of interest were selected and Intensity of each pixel was quantized in the array ranging from 0(white) to 255(black). The two groups were comparable with respect age, menopausal age, menopausal period and number of remaining teeth. The osteoporotic women had significantly lower alveolar bone density than controls in maxilla. But no significant difference was found with respect clinical attachment loss, plaque index and gingival index. Supported by the Ministry of Public Health and Welfare, Korea (HMP-00-CH-10-0009).

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.543-554
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• 2001

치주조직 재생을 도모하기 위한 전통적인 시술방법으로 여러가지 골이식재를 이용한 골이식술이 이용되고 있다. 이번 실험의 목적은 골형성을 위한 재료로 Calcium Polyphosphate(CPP)를 사용하여 비글견에서의 조직 반응과 골유도성을 보는 것이고 또한 다른 이식재들간에 신생골의 형성에 어느정도 영향을 주는 가를 알아보는 것이다. 이번 실험에 사용된 CPP는 무수 $Ca(H_2PO_4)$를 condensation하여 무결정의 $Ca(PO_3)_2$를 얻고 이를 용율하고 냉각시킨 후 분쇄하여 얻은 것으로 3세된 비글견에 이식하여 관찰하였다. 조직학적으로 CPP granule의 경우는 키토산이나 $Na_2O$를 넣은 경우 모두 bone 의 ingrowth가 관찰되었고 다른 섬유조직의 개재를 볼수 없었다 동결탈회건조골을 넣은 경우에는 주위로 골형성 보이지 않았고 단지 섬유성 조직이 관찰 되었다. 아무것도 넣지 않은 경우에 비해서 동결탈회건조골이나 키토산, $Na_2O$를 넣은 CPP granules 경우에 더 많은 비율로 신생 골의 양이 나타나는 것을 볼수 있었다. 아무것도 넣지 않은 대조군과 이식재를 넣은 군간에는 유의성이 있는 것으로 나타났고(p<0.05). 또한 CPP granules with chitosan과 CPP granules with $Na_2O$ 사이에는 신생골의 형성에 유의성이 없었다. 이것으로 보아 CPP granules with chitosan과 CPP granules with $Na_2O$는 모두 골유도성이 있고 신생골의 형성을 촉진하므로 치주질환으로 인한 골결손 부위에 사용할 수 있는 재료로 우수한 특성을 지닌다고 사료된다.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.113-123
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• 2006

연구배경 IgG에 대한 $Fc{\gamma}$ 수용기는 치주병인균에 대한 숙주 반응에 있어서 중요한 역할을 하는데, 이 중 $Fc{\gamma}RIIIa$는 NK 세포, 대식세포, 단핵구, ${\gamma}{\delta}T$세포에서 발현되며, EC2 도메인에서 158 아미노산 부위의 valine (V)-phenylalanine (F)의 유전자다형성을 보인다. $Fc{\gamma}RIIIb$는 특이적으로 중성구에 발현되는데, extracellular (ECl) Ig-like 도메인 내 4개의 아미노산 치환(substitutions)에 의한 NA1-NA2 유전자다형성을 보인다. 이 연구의 목적은 한국인에서 급진성 치주염 환자와 $Fc{\gamma}III$ 수용기의 유전자다형성과의 관련성을 알아보는 것이다. 연구방법 및 재료 치주적으로 건강한 90명 (대조군, 남자 64명, 여자 26명)과 서울대학교 치과병원 지주과에 내원하여 급진성 치주염으로 진단된 환자 43명 (aggressive periodontitis patients: AgP, 남자 30명, 여자 13명)을 대상으로 하였다. 모든 실험 대상자는 임상 실험에 대해 동의 하였고, 초진 시 전자 탐침(Florida Probe(R) Co. Gainesville, FL)을 이용하여 탐침 시 치주낭 깊이 (PPD), 임상부착수준 (CAL), 치태지수(PI), 탐침 후 출혈지수 (BOP)를 측정하였다. 또한 이들의 정맥혈에서 추출한 DNA를 PCR법, 전기영동법 등을 이용하여 $Fc{\gamma}RIIIa$, $Fc{\gamma}RIIIb$의 대립 유전자의 존재여부를 확인하였다. 이를 바탕으로 $Fc{\gamma}RIII$ 복합 유전형을 확인하여 각 군 간을 비교하였다. 연구 결과 1. $Fc{\gamma}RIIIa$에 대한 유전자다형성 연구 결과 대조군과 급진성 치주염 환자 군(AgP)사이에서는 대립 유전자 분포가 서로 유의성 있는 차이를 나타내었고 (P<0.05), $Fc{\gamma}RIIIb$에서는 유의성 있는 차이를 발견할 수 없었다. (P>0.05) 2. $Fc{\gamma}RIIIa$ 158F 대립형질이 급진성 치주염 환자에서 유의성 있게 많이 발견되어졌다. (P<0.05) 결론 이 연구를 통하여 $Fc{\gamma}RIIIa$ 유전자의 분석이 한국인의 급진성 치주염에 대한 감수성의 위험요소의 표지자로 활용할 수 있을 것으로 사료되며, 향 후 더 많은 환자를 대상으로 히는 추가 연구가 필요하다고 생각된다.

• Journal of Periodontal and Implant Science
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• 제44권3호
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• pp.126-133
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• 2014

Purpose: Smokeless tobacco-based oral-use products like gutka are popular in India. Gutka usage leads to increased periodontal destruction and inflammation; however, the relevant mechanism remains unknown. This study aimed to elucidate the role of gutka in periodontitis by examining its effect on the levels of interleukin (IL) $1{\beta}$ and IL-8 from the gingival crevicular fluid (GCF). Methods: A total of 45 patients were enrolled in this study. Thirty patients with periodontitis (15 gutka chewers [GCP] and 15 nongutka chewers [NGC]) and 15 periodontally healthy controls (HC) were selected. The full-mouth plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and recession (RC) were recorded. The IL-$1{\beta}$ and IL-8 levels in the GCF of all subjects were assessed through an enzyme-linked immunosorbent assay (Quantikine). Results: The IL-$1{\beta}$ and IL-8 levels were not significantly higher in the GCP group (IL-$1{\beta}$, $369.01{\pm}273.44{\mu}L$; IL-8, $205.97{\pm}196.78{\mu}L$) as compared to those in the NGC group (IL-$1{\beta}$, $195.57{\pm}96.85{\mu}L$; IL-8, $178.61{\pm}149.35{\mu}L$). More gingival RC and loss of attachment was seen among the GCP group (RC: $2.02{\pm}0.31$, P=0.013; CAL: $4.60{\pm}0.56$, P<0.001) than among the NGC group (RC, $1.21{\pm}1.15$; CAL, $3.70{\pm}0.32$); however, PD was deeper among the NGC subjects (P=0.002). PI and GI were significantly higher for the periodontitis group (P<0.001) when compared to the HC, but there was no difference among gutka chewers and non-chewers (P=0.22 and P=0.89). A positive correlation was found between the IL-8 levels and the duration of gutka chewing (r=-0.64, P<0.01). Conclusions: Gutka chewing leads to increased gingival RC and clinical loss of attachment. There was no effect seen in the proinflammatory cytokine levels in the GCF of gutka users.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.427-436
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• 2005

Objective: MMP-8 is a neutrophil enzyme and its level increases in some inflammatory diseases, including periodontal disease. We knew that the lipopolysaccharide of E.coli(E-LPS) induced MMP-8 release from human neutrophils. E-LPS is known to induce the production and release of inflammatory cytokines through CD14, Toll-like receptor(TLR). In the present study, we investigated whether MMP-8 release by E-LPS is induced via CD14-TLR pathway and the cellular mechanism of MMP-8 release in human neutrophils. Material and methods: Human neutrophils were isolated from the peripheral blood of healthy donors and pre-incubated in medium containing antibodies against CD14, anti-TLR2 and anti-TLR4 or several inhibitors of microtubules and microfilaments and then incubated with E-LPS. The cells were treated TPCK and E-LPS simultaneously. The MMP-8amount in the culture medium was determined using ELISA. Results: E-LPS increased MMP-8release from neutrophils and its induction was inhibited by anti-CD14 and anti-TLR4 but not by anti-TLR2 antibodies. The inhibitors of microtubule and microfilament polymerization significantly decreased E-LPS-induced MMP-8release. TPCK inhibited E-LPS-induced MMP-8 release. Conclusion: These results suggest that MMP-8 release is induced by E-LPS via the CD14-TLR4 signal pathway in human neutrophils and may be depedent on microtubule and microfilament systems and $NF-{\kappa}B$ pathway.

• 대한의용생체공학회:의공학회지
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• 제20권1호
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• pp.37-44
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• 1999

인공 슬관절에 사용되는 초고분자량 폴리에틸렌(Ultra-high molecular weight polyethylene : UHMWPE)의 마모는 삽입물의 수명을 결정하는 주요 요인으로 작용한다. UHMWPE의 마모로 입자가 발생하여 조직반응을 일으키고 이에 따른 일련의 반응으로 골용해가 일어나 인공관절의 실패의 원인으로 작용한다. 여러 보고들에 의하면 관절 운동시 발생하는 접촉응력은 UHMWPE의 마모에 영향을 미치는 주요한 인자 중 하나로 알려져 있다. 그러나 이러한 보고들은 관절 접촉면에서의 접촉 조건만을 고려했고 UHMWPE 삽입물을 지지하고 있는 금속 지지판과의 접촉면에서의 접촉 조건은 고려하지 않았다. 본 연구에서는 이러한 접촉 조건들을 고려하여 UHMWPE의 모양, 두께, 마찰, 굴곡 정도 그리고 구성 요소들에 대한 UHMWPE 표면과 내부에서의 응력해석을 통해 이들 변수가 UHMWPE의 마모현상에 미치는 영향을 알아보았다. UHMWPE의 모양에 따른 관절의 일치정도(conformity)에 대한 영향의 경우, 일치정도가 높은 모델이 응력을 줄여줄 수 있는 유형으로 나타났으며, 금속 지지판과의 접촉면에서 접촉조건을 준 경우가 완전히 결합된 것으로 가정한 경우보다 UHMWPE 내부에서의 최대 응력이 1-2mm 더 아래에서 나타났다. 또한 UHMWPE로만 된 유형이 금속 지지판이 있는 유형보다 낮은 응력분포를 보여줌으로써 높은 응력으로 인한 UHMWPE의 마모와 균열을 줄이기 위해서는 UHMWPE로만 된 유형의 삽입물의 사용이 좋을 것으로 사료되었다.