• 대한의생명과학회지
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• 제15권1호
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• pp.61-66
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• 2009

Leflunomide is an immunomodulatory agent used for the treatment of rheumatoid arthritis (RA). Leflunomide known as a regulator of iNOS synthesis which largely decreases NO production in diverse cell type. However, the effect of leflunomide on chondrocyte is still poorly understood. In our previous studies, we have shown that direct production of Nitric oxide (NO) by treating chondrocytes with NO donor, sodium nitroprusside (SNP), causes apoptosis via p38 mitogen-activated protein kinase in association with elevation of p53 protein level, caspase-3 activation. In this study, we characterized the molecular mechanism by which A77 1726 inhibit apoptosis. We found that A77 1726 inhibit NO-induced apoptosis as determined by MTT (Thiazolyl Blue Tetrazolium Bromide) assay and DNA fragmentation. The inhibition of apoptosis by A77 1726 was accompanied by increased PI-3 kinase and AKT activities. So, inhibition of phosphatidylinositol (PI)-3kinase with LY294002 rescued apoptosis. Triciribine, the specific inhibitor of AKT, also abolished anti-apoptotic effect. Our results indicate that A77 1726, the active metabolite of leflunomide, mediates NO-induced apoptosis in chondrocytes by modulating up-regulation of PI-3 kinase and AKT.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3358-3365
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• 2010

본 연구에서는 마가목 (SC), 현지초 추출물 (GT) 및 이들의 1:1 혼합물 시료 (MIX)가 골손실 및 연골손상 억제에 효과가 있는지 알아보기 위해, 각각의 시료를 조골세포주인 MG-63 세포, 파골세포로의 분화를 유도한 Raw264.7 세포와 연골세포로의 분화를 유도한 ATDC5 세포에 처리하여 세포분화 조절 정도를 확인하였다. 각 세포의 분화 정도는 alkaline phosphatase (ALP) 활성 측정, tartrate-resistant acid phosphatase (TRAP) 염색법 및 alcian-blue 염색법으로 확인하였다. 이들 시료는 MG-63 세포에서 ALP 활성에는 영향을 미치지 않았으나, 마가목 추출물 (SC) 및 마가목과 현지초 추출물의 혼합시료 (MIX)는 농도 의존적으로 파골세포의 분화를 억제하고 연골세포의 분화를 촉진하는 것으로 나타났다. 이상의 결과를 종합하여 볼 때, 마가목과 현지초는 골손실과 연골 손상으로부터 보호할 수 있는 중요한 천연물 소재임을 확인할 수 있었다. 나아가 이들 추출물의 작용기전 및 활성물질 구명에 대한 연구는 추후 더 진행되어야 할 것이다.

• 대한관절경학회지
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• 제11권1호
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• pp.1-6
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• 2007

목적: 슬관절 연골 결손 환자 치료로 진보적으로 변형된 gel 형태의 fibrin matrix 자가 연골 세포 이식술을 시행한 후 이차 관절경을 통하여 그 단기 결과를 알아보고자 하였다. 대상 및 방법: 슬관절 연골 결손 환자 6명을 대상으로 하였으며 결손 크기는 평균 $5.13\;cm^2$ 이었다. 1차 관절경 시술시 연골 전층을 채취하여 $4{\sim}6$주간 배양하여 연골 세포를 증식한 후, 2차로 fibrin을 matrix로 하는 gel 형태의 자가 연골 세포 이식술을 시행하였다. 결과: 수술 후 Modified Cincinnati Knee Score는 6명중 4예에서 양호 이상, Lysholm function score는 수술 전 평균 59.5점에서 수술 후 평균 75.25점으로 증상이 호전되었다. ICRS grade 측정에서 6명중 4예에서 거의 정상의 결과를 보였다. 결론: Gel 형태의 fibrin matrix 자가 연골 세포 이식술은 기존의 고식적인 방법에 비해 수술시간이 짧고, 최소 절개 또는 관절경적 시술이 가능한 유용한 방법으로 사료되나, 추후 더 많은 증례 및 지속적인 장기 추시가 필요할 것으로 생각된다.

• Tribology and Lubricants
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• 제21권5호
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• pp.236-240
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• 2005

In order to prepare for the suitable surfaces of implants or medical devices, quantitative evaluation of adhesion between cells and biomaterials is essential. To better understand adhesion formation between cells and biomaterials, we used the cytodetachment technique which measures the adhesive force of a single cell through changing the, culture time and detachment speed. The results showed that the adhesive force could be affected by the culture time of cells on the surface of materials and the detachment speed. Moreover, there was a large discrepancy among the adhesion strength measured by similar techniques conducted on the different cells and substrates. It can be 'concluded that the variation of the force measurement technique can seriously alter the level of the force required to detach a cell on the surface of materials.

• Archives of Plastic Surgery
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• 제47권5호
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• pp.392-403
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• 2020

Severe cartilage defects and congenital anomalies affect millions of people and involve considerable medical expenses. Tissue engineering offers many advantages over conventional treatments, as therapy can be tailored to specific defects using abundant bioengineered resources. This article introduces the basic concepts of cartilage tissue engineering and reviews recent progress in the field, with a focus on craniofacial reconstruction and facial aesthetics. The basic concepts of tissue engineering consist of cells, scaffolds, and stimuli. Generally, the cartilage tissue engineering process includes the following steps: harvesting autologous chondrogenic cells, cell expansion, redifferentiation, in vitro incubation with a scaffold, and transfer to patients. Despite the promising prospects of cartilage tissue engineering, problems and challenges still exist due to certain limitations. The limited proliferation of chondrocytes and their tendency to dedifferentiate necessitate further developments in stem cell technology and chondrocyte molecular biology. Progress should be made in designing fully biocompatible scaffolds with a minimal immune response to regenerate tissue effectively

• 대한의생명과학회지
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• 제15권1호
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• pp.67-72
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• 2009

Microtubule-interfering agents (MIAs), including paclitaxel, have been attributed in part to interference with microtubule assembly, impairment of mitosis, and changes in cytoskeleton. But the signaling mechanisms that link microtubule disarray to destructive or protective cellular responses are poorly understood. This study investigated the effect of paclitaxel on differentiation such as type II collagen expression and sulfated proteoglycan accumulation in rabbit articular chondrocytes. Paclitaxel caused differentiated chondrocyte phenotype as demonstrated by increment of type II collagen expression and proteoglycan synthesis Paclitaxel treatment stimulated activation of ERK-1/2 and p38 kinase. Inhibition of ERK-1/2 with PD98059 enhanced paclitaxel-induced differentiation, whereas inhibition of p38 kinase with SB203580 suppressed paclitaxel-induced differentiation. Our findings suggest that ERK-1/2 and p38 kinase oppositely regulate paclitaxel-induced differentiation in chondrocytes.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.155.1-155.1
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• 2005

• Archives of Plastic Surgery
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• 제40권6호
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• pp.676-686
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• 2013

Background To overcome the potential drawbacks of a short half-life and dose-related adverse effects of using active transforming growth factor-beta 1 for cartilage engineering, a cell-mediated latent growth factor activation strategy was developed incorporating latent transforming growth factor-${\beta}$1 (LTGF) into an electrospun poly(L-lactide) scaffold. Methods The electrospun scaffold was surface modified with NH3 plasma and biofunctionalised with LTGF to produce both random and orientated biofunctionalised electrospun scaffolds. Scaffold surface chemical analysis and growth factor bioavailability assays were performed. In vitro biocompatibility and human nasal chondrocyte gene expression with these biofunctionalised electrospun scaffold templates were assessed. In vivo chondrogenic activity and chondrocyte gene expression were evaluated in athymic rats. Results Chemical analysis demonstrated that LTGF anchored to the scaffolds was available for enzymatic, chemical and cell activation. The biofunctionalised scaffolds were non-toxic. Gene expression suggested chondrocyte re-differentiation after 14 days in culture. By 6 weeks, the implanted biofunctionalised scaffolds had induced highly passaged chondrocytes to re-express Col2A1 and produce type II collagen. Conclusions We have demonstrated a proof of concept for cell-mediated activation of anchored growth factors using a novel biofunctionalised scaffold in cartilage engineering. This presents a platform for development of protein delivery systems and for tissue engineering.

• 동의생리병리학회지
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• 제22권5호
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• pp.1262-1269
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• 2008

Low intensity pulsed ultrasound(LIPUS) is known to accelerate bone regeneration, but the precise cellular signaling mechanism is still unclear. The purpose if this study was to determine the effect of LIPUS on the signaling mechanism of rat chondrocyte. In the explant culture condition, there was inhibition effect of 1 $W/cm^2$ intensity LIPUS on chondrocytes proliferation but chondrocytes proliferation was increased at 0.25 $W/cm^2$ intensity. In addition, western blot analysis of MAPKs showed that LIPUS increased ERK1/2 activity from the 10 min treatment of LIPUS. Hydrogen peroxide($H_2O_2$), resulted in a time- and dose-dependent cell proliferation, which was largely attributed to apoptosis. $H_2O_2$ treatment caused marked sustained nucleus condensation in Hoechst stain. LIPUS and $H_2O_2$ activates phosphorylation of p-ERK1/2 and PD 98059($10^{-5}M$) blocked the effect of LIPUS and $H_2O_2$. Moreover, the synergistic phosphorylation of p44/42 MAPK by $H_2O_2$, LIPUS was selectively inhibited by PD 98059, ERK1/2 inhibitor. In order to determine whether the increase in cell proliferation caused by $H_2O_2$ and LIPUS could be explained by changes in the level of the prostaglandin $E_2$. Our study demonstrated that LIPUS stimulate the cell proliferation via activated phosphorylation of ERK1/2 in condrocyte. LIPUS has anabolic effects on rat cartilage in explant cultures, indicating a potential important method for the treatment of osteoarthritic cartilarge.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어의학회 2003년도 제19회 학술대회
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• pp.183-183
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• 2003

Background and Objectives : Cartilage reconstruction is one of medical issue in otolaryngology. Tissue engineering is presently being utilized in part of cartilage repair. Sources of cells for tissue engineering are chondrocyte from mature cartilage and bone marrow mesenchymal stem cells that are able to differentiate into chondrocyte. Recent studies have shown that adipose tissue have mesenchymal stem cells which can differentiate into adipogenic, chondrogenic myogenic osteogenic cells and neural cell in vitro. In this study, we have examined chondrogenic potential of the canine adipose tissue-derived mesenchymal stem cell(ATSC). Materials and Methods : We harvested canine adipose tissue from inguinal area. ATSCs were enzymatically released from canine adipose tissue. Under appropriate culture conditions, ATSCs were induced to differentiate into the chondrocyte lineages using micromass culture technique. We used immunostain to type II collagen and toluidine blue stain to confirm chondrogenic differentiation of ATSCs. Results : We could isolate ATSCs from canine adipose tissue. ATSCs expressed CD29 and CD44 which are specific surface markers of mesenchymal stem cell. ATSCs differentiated into micromass that has positive response to immunostain of type II collagen and toluidine blue stain. Conclusion : In vitro, ATSCs differentiated into cells that have characteristic cartilage matrix molecules in the presence of lineage-specific induction factors. Adipose tissue may represent an alternative source to bone marrow-derived MSCs.