Multiwalled Carbon Nanotubes Functionalized with PS via Emulsion Polymerization

Park, In-Cheol,Park, Min,Kim, Jun-Kyung,Lee, Hyun-Jung,Lee, Moo-Sung The Polymer Society of Korea 2007 Macromolecular Research Vol.15 No.6

This study demonstrated the in-situ functionalization with polymers of multi-walled carbon nanotubes (MWNTs) via emulsion polymerization. Polystyrene-functionalized MWNTs were prepared in an aqueous solution containing styrene monomer, non-ionic surfactant and a cationic coupling agent ([2-(methacryloyloxy)ethyl]trime-thylammonium chloride (MATMAC)). This process produced an interesting morphology in which the MWNTs, consisting of bead-string shapes or MWNTs embedded in the beads, when polymer beads were sufficiently large, produced nanohybrid material. This morphology was attributed to the interaction between the cationic coupling agent and the nanotube surface which induced polymerization within the hemimicellar or hemicylindrical structures of surfactant micelles on the surface of the nanotubes. In a solution containing MATMAC alone without surfactant, carbon nanotubes (CNTs) were not well-dispersed, and in a solution containing only surfactant without MATMAC, polymeric beads were synthesized in isolation from CNTs and continued to exist separately. The incorporation of MATMAC and surfactant together enabled large amounts of CNTs (> 0.05 wt%) to be well-dispersed in water and very effectively encapsulated by polymer chains. This method could be applied to other well-dispersed CNT solutions containing amphiphilic molecules, regardless of the type (i.e., anionic, cationic or nonionic). In this way, the solubility and dispersion of nanotubes could be increased in a solvent or polymer matrix. By enhancing the interfacial adhesion, this method might also contribute to the improved dispersion of nanotubes in a polymer matrix and thus the creation of superior polymer nanocomposites.

Engineering of AlON interlayer in Al₂O₃/AlON/In_0.53Ga_0.47As gate stacks by thermal atomic layer deposition

Lee, Woo Chul,Cho, Cheol Jin,Park, Suk-In,Jun, Dong-Hwan,Song, Jin Dong,Hwang, Cheol Seong,Kim, Seong Keun ELSEVIER 2018 CURRENT APPLIED PHYSICS Vol.18 No.8

<P>The presence of an AlN interfacial layer in high-k/In0.53Ga0.47As gate stacks improves the interfacial properties and enhances the electrical performance of devices. However, pure AlN is rarely grown by atomic layer deposition (ALD) because of the low reactivity of NH3 toward the common Al-precursor and the predisposition to oxidation of the grown AlN layer. Although a plasma-enhanced ALD technique significantly suppresses the oxygen content in the grown AlN layer, the deterioration of the interface properties by plasma-damage is a critical issue. In this work, an AlON interlayer was engineered by optimizing the NH3 feeding time in thermal ALD to improve the interface quality in Al2O3/AlON/In0.53Ga0.47As capacitors. It was determined that a mere increase in the NH3 feeding time during the ALD of the AlON film resulted in a higher nitrogen incorporation into the AlON interlayer, leading to a reduction in the interface trap density. Furthermore, the out-diffusion of elements from the In0.53Ga0.47As layer was effectively suppressed by increasing the NH3 feeding time. This work demonstrates that simple process optimization can improve the interface quality in high-k/In0.53Ga0.47As gate stacks without the use of any plasma-activated nitrogen source.</P>

국립공원 아고산대 독립훼손지 복원식생 분포특성 및 관리방안

김종엽(Jong-Yup Kim),윤주웅(Ju-Ung Yun),한봉호(Bong-Ho Han),곽정인(Jeong-In Kwak),박석철(Seok-Cheol Park),박수영(Su Young Park),정원옥(Won-Ok Jeong) 국립공원연구원 2022 국립공원연구지 Vol.13 No.1

본 연구는 독립훼손지 중 아고산대에 위치한 지리산국립공원 세석평전과 노고단 복원식생지를 대상으로 현존식생 분석 및 식생분포 특성을 파악하여 중장기적인 모니터링 및 관리방안 수립을 위한 기초자료를 제공하고자 수행하였다. 현존식생 조사범위는 훼손지 일대 유역권분포 현황을 고려하여 설정하였으며, 세석평전 조사면적은 55,037㎡, 노고단 조사면적은 166,599㎡ 이었다. 세석평전은 초본층에 의한 식생피복도는 90% 이상 수준으로서 나지노출이 없었고, 관목층의 피복도가 60% 이상으로 안정화되어 있었다. 주요 출현수종은 구상나무, 사스래나무, 쇠물푸레나무, 철쭉, 털진달래, 붉은병꽃나무 등 식재수종과 자연적으로 이입한 자생수종이 생육하고 있었다. 노고단은 신갈나무, 호랑버들, 철쭉, 털진달래, 미역줄나무 등이 우점하는 관목식생지가 52%로 가장 넓게 분포하고 있었고, 전반적으로 식생활착 상태가 양호하였다. 노고단의 원식생은 신갈나무군락으로 추정되었고, 군부대철거지에는 귀화식물이 분포하고 있기 때문에 적극적인 관리가 필요하였다. 연구대상지는 장기적으로 주변 자연식생과 조화로운 식생경관으로 발달할 것으로 예측되었다. 향후 훼손지 복원모델은 인근 지역의 원식생을 고려하여 설정해야 할 것이지만, 복원 달성 목표는 실현가능한 수준의 목표를 설정해야 할 것이다. This study was conducted to provide basic data for mid-to long-term monitoring and establishment of management plans by analyzing the existing vegetation and identifying the vegetation distribution characteristics for the restored vegetation in Nogodan and Seseokpyeongjeon in Jirisan National Park located in the subalpine zone among the independent damaged areas. Actual vegetation survey range was established in consideration of the distribution of the watershed around the damaged area. The surveyed area of Seseokpyeongjeon was 55,037㎡, and the surveyed area of Nogodan was 166,599㎡. In Seseokpyeongjeon, the vegetation coverage by the herbaceous layer was almost 90% or more, there was no bare exposure, and the coverage of the shrub layer was stabilized at 60% or more. The main emerging tree species were planted species such as Abies koreana, Betula ermanii, Fraxinus sieboldiana, Rhododendron schlippenbachii, Rhododendron mucronulatum var. ciliatum, and Weigela florida as well as natively migrated native species. In Nogodan, the shrub vegetation dominated by Quercus mongolica, Salix caprea, Rhododendron schlippenbachii, Rhododendron mucronulatum var. ciliatum, and Tripterygium regelii was the most widely distributed with 52% of the area, and the overall diet was good. The native vegetation of Nogodan was presumed to be a cypress colony. Naturalized plants were distributed in the military base demolition site, so active management was required. The study site was predicted to develop into a vegetation landscape in harmony with the surrounding natural vegetation in the long term. In the future, the restoration model for damaged areas should be set in consideration of the native vegetation of the nearby area, but the goal to achieve restoration should be set at a feasible level.

Nuclear factor I-C가 치근발생 과정에서 Hertwig's 상피초 형성에 미치는 영향

신인철,박주철,정문진,오현주,박선화,이창섭,김흥중,Shin, In-Cheol,Park, Joo-Cheol,Jeong, Moon-Jin,Oh, Hyun-Ju,Park, Sun-Hwa,Lee, Chang-Seop,Kim, Heung-Joong 대한소아치과학회 2005 大韓小兒齒科學會誌 Vol.32 No.3

치아의 형성은 상피-간엽간의 상호작용을 통해 조절되어지는 복잡한 발생과정이다. 지금까지 치관의 발생에 관여하는 유전자 및 그들의 신호전달경로에 관한 연구는 다수 진행되어 왔지만 치근의 발생을 조절하는 기전에 대해서는 별로 알려진 것이 없다. 최근에 NFI-C knock out 생쥐에서 정상치관에 비정상적인 치근을 가지는 치아가 보고되었다. 본 연구의 목적은 NFI-C가 어떻게 치근의 형태와 상아모세포의 분화에 관여하는지를 규명하는 것이다. NFI-C knock out 생쥐의 치근 발생동안에 HERS의 역할을 연구하고자 cytokeratin 면역조직화학적방법과 치근상아질의 특성을 규명하기 위해 DSPP mRNA in-situ hybrydization법을 수행하였다. 1. NFI-C knock out 생쥐의 치근형성시 HERS의 역할 Wild type과 knock out type 모두에서 cytokeratin은 모든 HERS 세포들과 반응하였고, HERS와 법랑상피 사이의 양성반응세포들의 연속성은 치경부 부위에서 소실되었다. Knock out type에서 치근상아질이 침착된 후, cytokeratin 양성-HERS 세포들은 치경부에서 불규칙한 배열과 극성의 상실을 보였다. 2. NFI-C knock out 생쥐의 치근상아질의 특성 DSPP mRNA의 발현은 wild type에서 치관과 치근상아질의 상아모세포 모두에서 강한 발현을 보인 반면, knock out type에서는 치관부위 상아질의 상아모세포에서만 강한 발현을 보였다. 3. NFI-C knock out 생쥐의 치근 발생과정에서 HERS는 치관으로부터 정상적인 확장을 보인 반면, 치근부위에서의 상아 모세포 분화는 실패하였다. 위의 결과들로 보아 NFI-C는 치근형성 과정에서 상아모세포 분화에 중요한 역할을 하는 것으로 사료된다. Tooth formation is a complex developmental process that is mediated through a series of reciprocal epithelial-mesenchymal interactions. Several signal pathways and transcription factors have been implicated in regulating molar crown development, but relatively little is known about the regulation of root development. It was reported that NFI-C knockout mice showed abnormal root formation with normal crown. The aims of this study are to elucidate how the NFI-C regulate the determine of root shape and odontoblasts differentiation. We carried out immunohistochemistry using cytokeratin to investigate the role of Hertwig's epithelial root sheath and DSPP mRNA in-situ hybridization to conform the nature of root dentin during root development in NFI-C knockout mice. Cytokeratin reacted with all the HERS cells and the continuity of cytokeratin positive cells between the HERS cells and enamel epithelium was lost in the cervical region both wild and K/O types. After root dentin deposition cytokeratin positive-HERS cells showed irregularity and loss of polarity in the cervical region in K/O type. DSPP mRNA was strongly expressed in odontoblasts of crown and root dentin in wild type mice, whereas expression of DSPP mRNA was restricted in odontoblast of crown dentin in the K/O type. During root formation in NFI-C knockout mice, HERS normally grow out of the crown but fail to induce odontoblast differentiation in root portion. These results suggest that NFI-C may play important roles in odontoblast differentiation during root dentin formation.

절제된 정상위벽의 자기공명영상기법에 관한 연구:조직소견과의 비교

서보경,설혜영,이남준,차인호,정규병,김정혁,박철민,이지영,Seo, Bo-Gyeong,Seol, Hye-Yeong,Lee, Nam-Jun,Cha, In-Ho,Jeong, Gyu-Byeong,Kim, Jeong-Hyeok,Park, Cheol-Min,Lee, Ji-Yeong 대한영상의학회 2001 대한영상의학회지 Vol.45 No.5

목적:급속자기공명영상기법을 이용하여 절제된 정상위벽을 관찰하고,이를 조직소견과 비교 연구하여,위벽의 관찰을 위한 최적기법을 찾고자 하였다. 대상과 방법:25명 환자의 모두 41개 절제된 정상위조직을 수술후 수지(polyethylene)통에 넣고,생리식염수로 채워 자기공명영상을 시행하였다.T1강조FLASH,지방억제T1강조FLASH, T2강조TSE와 True-FISP 등 4가지 기법으로 위조직의 영상을 얻었다.자기공명영상에서는 위벽의 층수와 각층의 신호강도를 관찰하였고,이를 조직소견과 비교하였다.자기공명영상소견을 조직소견과 비교한 후 위벽 각층의 명확성과 각층간의 구분,및 전체 영상의 질에 대하여 비교하였다.4가지 기법 중 가장 좋은 방법은 3,가장 나쁜 방법은 0으로 하여 등급을 판정하였다. 결과:자기공명영상에서 위벽의 층수는 T1강조FLASH에서 2층이 41예 중 6예(14.6%),3층 31예(75.6%),및 4층 4예(9.8%)였고,지방억제T1강조FLASH에서 2층 6예(14.6%)와 3층 35예(85.4%),T2강조TSE에서 3층 24예(58.5%),4층 11예(26.8%),및 5층 6예(14.6%)였으며,True-FISP에서 1층 2예(4.9%),2층 8예(19.5%),3층 23예(56.0%),4층은 4예(9.8%), 및 5층 4예(9.8%)이었다.위벽의 신호강도는 T1강조FLASH와 지방억제T1강조FLASH에서 2층으로 보인 예는 위내강으로부터 고-중등도,3층인 경우는 고-저-고/중등도,4층인 예는 고-저-고-중등도신호강도였다.T2강조TSE에서는 3층으로 보인 예는 등도/고-저-중등도,4 층인 경우는 중등도-저-고-중등도/저,5층인 예는 저-고-저-고-저신호강도였다.자기공명 영상소견을 조직소견과 비교하였을 때 위벽이 3층으로 보인 경우 이것은 “점막층-점막하층-근층 ”에 해당하였다.관찰한 3가지 면 모두에서 T1강조FLASH,지방억제T1강조FLASH,T2강조TSE 기법이 True-FISP보다 통계적으로 유의하게 우수하였다(p=0.001).점막층의 명확성에 있어서 가장 우수한 기법은 T1강조FLASH와 지방억제T1강조FLASH이었고(p<0.05),점막하층의 명확성과 점막하층과 근층간의 구분은 T2강조TSE가 가장 우수하였다(p<0.05).전체적인 영상의 질은 T1강조FLASH와 T2강조TSE에서 가장 우수하였다(p<0.05). 결론:자기공명영상은 위벽의 각 층을 구별할 수 있는 우수한 검사로 조직소견과 높은 연관성을 보이며,전체 영상의 질,점막하층의 명확성 및 점막하층과 근층간의 구분이 T2강조TSE에서 가장 우수한다. Purpose: To evaluate normal human gastric wall layers in vitro using magnetic resonance*(MR) imaging, to correlate the results with the histologic findings, and to determine the optimal technique for evaluation of the gastric wall. Materials and Methods: Forty-one normal resected gastric specimens obtained from 25 patients were dissected and placed in a polyethylene tube filled with normal saline. MR imaging with four MR sequences, T1-weighted FLASH*(T1FLASH), fat-saturated T1-weighted FLASH, T2-weighted TSE*(T2TSE), and True-FISP, was performed. The number of gastric wall layers and signal intensity of each layer were determined, and after correlating MR images with the histologic findings, the conspicuity of each layer*(mucosa, submucosa, and muscle), the distinction between each layer, and overall image quality were assessed. results: The gastric wall was shown by TIFLASH to have two (n=6, 14-6%), three (n=31, 75.6%) and four layers (n=4, 9.8%); by fat-saturated TIFLASH to have two (n=6, 14.6%) and three (n=35, 85.4%) ; by T2TSE to have three (n=24, 58.5%), four (n=11, 26.8%), and five (n=6, 14.6%); and by True-FISP to have one (n=2, 4.9%), two (n=8, 19.5%), three (n=23, 56%), four (n=4, 9.8%), and five (n=4, 9.8%) . The signal intensity of each layer at T1FLASH and fat-saturated T1FLASH was high-intermediate from the lumen in two-layer cases, high-low-high/intermediate in three-layer cases, and high-low-high-intermediate in four-layer cases. The signal intensity of each layer at T2TSE was intermediate/high-low-intermediate in three-layer cases, intermediatelow-high-intermediate/low in four-layer cases, and low-high-low-high-low in five-layer cases. Three-layered gastric wall corresponded mostly to mucosa, submucosa, and muscle from the inner to outer layers, respectively. T1FLASH, fat-saturated T1FLASH, and T2TSE were superior to True-FISP in evaluating the gastric wall. T1FLASH and fat-saturated T1FLASH were the best sequences for demonstrating mucosa (p<0.05), and T2TSE was the best for submucosa and the distinction between this and muscle (p<0.05). Both T1FLASH and T2TSE provided the best overall image quality (p<0.05). Conclusion: In-vitro MR imaging is an excellent technique for the evaluation of layers of normal gastric wall. T2TSE is the sequence which best demonstrates the conspicuity of submucosa, the distinction between submucosa and muscle, and overall image quality.

Comparison of prasugrel versus clopidogrel in Korean patients with acute myocardial infarction undergoing successful revascularization

Park, Keun-Ho,Jeong, Myung Ho,Kim, Hyun Kuk,Ahn, Tae Hoon,Seung, Ki Bae,Oh, Dong Joo,Choi, Dong-Joo,Kim, Hyo-Soo,Gwon, Hyeon Cheol,Seong, In Whan,Hwang, Kyung Kuk,Chae, Shung Chull,Kim, Kwon-Bae,Kim, Elsevier 2018 Journal of cardiology Vol.71 No.1

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Although there have been several reports that prasugrel can improve clinical outcomes, the efficacy and safety of prasugrel is unknown in Korean patients with acute myocardial infarction (AMI) undergoing successful revascularization.</P> <P><B>Methods</B></P> <P>A total of 4421 patients [637 patients were prescribed prasugrel (60/10 or 5mg, loading/maintenance dose) and 3784 patients clopidogrel (600 or 300/75mg)] with AMI undergoing successful revascularization were enrolled from the core clinical cohort of Korea Acute Myocardial Infarction Registry-National Institute of Health.</P> <P><B>Results</B></P> <P>After propensity score matching (637 pairs), there were no significant differences in baseline clinical and procedural characteristics and in-hospital medications between the two groups. The primary efficacy endpoint, defined as the composite of cardiac death, MI, stroke, or target vessel revascularization at 6 months showed no significant difference between prasugrel and clopidogrel (2.4% vs. 2.9%, <I>p</I> =0.593). Also, no difference was observed in the composite of cardiac death, MI, or stroke during hospitalization between two groups (0.8% vs. 0.9%, <I>p</I> =0.762). However, the incidence of in-hospital Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding was significantly higher in prasugrel compared with clopidogrel (5.3% vs. 2.7%, <I>p</I> =0.015). In multivariate linear regression analysis, trans-femoral intervention, use of glycoprotein IIb/IIIa inhibitors, use of calcium channel blocker, and use of prasugrel were independent predictors of in-hospital TIMI major or minor bleeding [odds ratio (OR)=6.918; 95% confidence interval (CI)=2.453–19.510, OR=2.577; 95% CI=1.406–4.724, OR=4.016; 95% CI=1.382–11.668, OR=2.022; 95% CI=1.101–3.714].</P> <P><B>Conclusions</B></P> <P>Our study shows that the recommended dose of prasugrel had significantly higher in-hospital bleeding complications without reducing ischemic events compared with clopidogrel. However, further large-scale, long-term, randomized clinical trials are required to accurately assess the efficacy and safety of prasgurel and to find out the optimal dose for Korean AMI patients.</P>

로자탄 대 포시노프릴의 고혈압 환자들에서 항고혈압 효과, 안전성 및 내약성의 비교

박대균,이명묵,채인호,이무용,이홍자,김효수,김철호,손대원,오병희,박영배,최윤식 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.1

법랑모세포 분화와 법랑질 형성과정에서 OD314, Apin protein의 발현 및 기능

박종태,최용석,김흥중,정문진,오현주,신인철,박주철,손호현 대한치과보존학회 2006 Restorative Dentistry & Endodontics Vol.31 No.6

본 연구에서는 법랑모세포 분화와 법랑질 형성에 연관이 있는 OD314 일명 Apin protein의 기능을 밝힐 목적으로, in-situ hybridization에 의한 OD314 mRNA 발현과 법랑모세포 세포주에서 OD314 enamel matrix protein의 발현, 그리고 OD314 유전자를 과발현/억제시킬 수 있는 construct를 제작한 후 법랑질 형성 중에 OD314의 기능을 알아보고자 RT-PCR를 시행하여 다음과 같은 결과를 얻었다. 1. OD314 mRNA는 발생중인 상아모세포보다 법랑모세포에서 강하게 발현되었다. 2. Tuftelin은 석회화 결정이 형성되는 14일까지 발현이 지속되고, 그 이후부터 점차 감소하였다. Amelogenin과enamelin은 7일부터 그 발현이 점점 감소하였다. 3. U6-OD314 siRNA construct를 이용하여 transfection한 법랑모세포 세포주는 OD314와 tuftelin,MMP2 mRNA 발현이 감소하였으며, CM-OD314를 transfection하여 OD314의 과발현을 유도한 경우에는 OD314와 MMP20 mRNA의 발현이 뚜렷이 증대되었다. 이 결과는 OD314가 법랑모세포의 분화와 법랑질의 형성 그리고 석회화 과정에 중요한 역할을 하는 새로운 인자임을 시사한다. This study was aimed to elucidate the biological function of OD314 (Apin protein), which is related to ameloblast differentiation and amelogenesis. Apin protein, calcifying epithelial odontogenic (pindborg) tumors (CEOTs)-associated amyloid, were isolated from CEOTs, and has similar nucleotide sequences to OD314. We examined expression of the OD314 mRNA using in-situ hybridization during tooth development in mice. Expression of OD314 and several enamel matrix proteins were examined in the cultured ameloblast cell line up to 28 days by reverse transcription-polymerase chain reaction (RT-PCR) amplification. After inactivation and over-expression of the OD314 gene in ameloblast cell lines using U6 vector-driven RNA interference and CMV-OD314 construct, RT-PCR were performed to evaluate the effect of the OD314 during amelogenesis. The results were as follows: 1. In in-situ hybridization, OD314 mRNAs were more strongly expressed in ameloblast than odontoblast. 2. When ameloblast cells were cultured in the differentiation and mineralization medium for 28 days, the tuftelin mRNA expression was maintained from the beginning to day 14, and then gradually decreased to day 28. The expressions of amelogenin and enamelin were gradually decreased according to the ameloblast differentiation. 3. Inactivation of OD314 by U6-OD314 siRNA construct down-regulated the expression of OD314, MMP-20, and tuftelin, whereas over-expression of OD314 by CMV-OD314 construct up-regulated the expression of OD314 and MMP-20 without change in tuftelin. These results suggest that OD314 is considered as an ameloblast-enriched gene and may play the important roles in ameloblast differentiation and mineralization.

Effects of combination therapy of statin and N-acetylcysteine for the prevention of contrast–induced nephropathy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Park, Soo Hwan,Jeong, Myung Ho,Park, In Hyae,Choi, Jin Soo,Rhee, Jung Ae,Kim, In Soo,Kim, Min Cheol,Cho, Jae Yeong,Sim, Doo Sun,Hong, Young Joon,Park, Hyung Wook,Kim, Ju Han,Ahn, Youngkeun,Cho, Jeong Elsevier 2016 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.212 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Acute myocardial infarction (AMI) is a risk factor for contrast-induced nephropathy (CIN). We investigated whether pretreatment with statin, N-acetylcysteine (NAC) and sodium bicarbonate (NaHCO<SUB>3</SUB>) reduces the risk of CIN.</P> <P><B>Methods</B></P> <P>We conducted a prospective trial and enrolled a total of 334 ST-segment elevation myocardial infarction (STEMI) patients. Patients were divided into four groups: Group I (statin 40mg), Group II (statin 80mg), Group III (statin 80mg plus NAC 1200mg) and Group IV (regimen of group III plus NaHCO<SUB>3</SUB> 154mEq/L). CIN was defined as ≥25% or ≥0.5mg/dL increase in serum creatinine from the baseline within the 72h after PCI.</P> <P><B>Results</B></P> <P>CIN occurred in 72 (21.6%) patients. The incidence of CIN was the lowest in the group III (14.3%), and multivariate analysis showed the lower incidence of CIN in group III compared to Group I [odds ratio (OR) 0.29, 95% confidence interval (CI) 0.13–0.64, p=0.002]. Admission hyperglycemia [(AHG)>198mg/dL] (OR 2.20, 95% Cl 1.20–3.68, p=0.011) and the use of intra-aortic balloon pump (IABP) (OR 4.20, 95% CI 1.38–12.78, p=0.016) were independent predictors for CIN. The CIN (OR 9.00, 95% CI 1.30–62.06, p=0.026) was an independent predictor for in-hospital mortality.</P> <P><B>Conclusions</B></P> <P>Combination of high-dose statin plus NAC was associated with lower incidence of CIN in patients with STEMI who underwent primary PCI compared to statin only.</P>

법랑모세포 분화와 성숙과정에서 OD314의 발현

박주철,안성민,김흥중,정문진,박민주,신인철,손호현 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.5

법랑모세포는 법랑질을 형성하고 유지하는 세포로, 법랑질의 유기기질을 분비하고 법랑질 석회화 과정에도 관여한다. 치아 발생과정에서 법랑모세포의 분화는 순차적인 상피-간엽 상호작용에 의하여 조절되나, 분화나 성숙과정의 정확한 기전은 아직까지 잘 알려져 있지 않다. 최근에 상아모세포에서 처음 발견된 OD314가 치아 발생과정에서 상아질을 형성하는 상아모세포 뿐 아니라 법랑모세포에도 발현된다고 하였다. 이에 본 연구에서는 생쥐 하악 전치의 다양한 시기의 법랑모세포를 이용하여, 형태학적 분석과 in-situ hybridization에 의한 OD314 mRNA의 발현 그리고 OD314 항체를 이용한 면역조직화학적 분석을 통하여 OD314 유전자의 법랑 모세포 분화와 성숙과정에서의 역할을 연구하여 다음과 같은 결과를 얻었다. 1. 형태학적으로 법랑모세포는 분화 단계에 따라 분비 전단계 법랑모세포, 분비기 법랑모세포, 성숙기의 평탄끝 법랑모세포와 성숙기의 주름끝 법랑모세포로 구분되었다. 2. OD314 mRNA는 분비기의 법랑모세포에서부터 발현되기 시작하여 법랑모세포가 성숙해갈 수록 그 발현이 증가하였다. 3. OD314 단백질은 분비 전단계의 법랑모세포에서는 발현되지 않고, 분비기의 법랑모세포에서는 세포질에 전체적으로 발현되었다. 성숙기의 평탄끝 법랑모세포와 주름끝 법랑모세포에서는 세포의 근심과 원심끝단에 OD314 단백질이 강하게 발현되었다. 이상의 결과를 종합하여 OD314는 법랑모세포의 분화와 성숙과정에서 세포질 내부에서 특징적인 역할을 하는 것으로 사료된다. Ameloblasts are responsible for the formation and maintenance of enamel which is an epithelially derived protective covering for teeth. Ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions. However, little is known about the differentiation and maturation mechanisms. OD314 was firstly identifled from odontoblasts by subtraction between odontoblast/pulp cells and osteoblast/dental papilla cells, even though OD314 protein was also expressed in ameloblast during tooth formation. In this study, to better understand the biologcal function of OD314 during amelogenesis, we examined expression of the OD314 mRNA and protein in various stages of ameloblast differentiation using in-situ hybridization and immunohistochemistry. The results were as follows : 1. The ameloblast showed 4 main morphological and functional stages referred to as the presecretory, secretory, smooth-ended, and ruffle-ended. 2. ○D314 mRNA was expressed in secretory ameloblast and increased according to the maturation of the cells. 3. OD314 protein was not expressed in presecretory ameloblast but expressed in secretory ameloblast and maturative ameloblast. OD314 protein was distributed in entire cytoplasm of secretory ameloblast. However, OD314 was localized at the proxiamal and distal portion of the cytoplasm of smooth- ended and ruffle-ended ameloblast. These results suggest that ○D314 may play important roles in the ameloblast differentiation and maturation.