Biosynthetic processing of fibrillar procollagens is essential for producing mature collagen monomers that polymerize into fibrils by a self-assembly process. The metalloproteinase ADAMTS-2 is the major enzyme that processes the N-propeptide of type I procollagen in the skin and also of type II and type III procollagens. Mutations in the ADAMTS-2 gene cause dermatospraxis in animals and Ehlers-Danlos syndrome VIIC in humans, both of which are characterized by the accumulation of type I pN-collagen and the formation of abnormal collagen fibrils in the skin. Despite its importance in procollagen processing, little is known about the regulation of ADAMTS-2 expression. Here, we demonstrate that ADAMTS-2 can be regulated by 1,25-dihydroxyvitamin D3, an inducer of type I procollagen synthesis. This steroid hormone induced ADAMTS-2 mRNA ~3-fold in MG-63 human osteosarcoma cells and MC3T3-E1 murine osteoblastic cells. This induction was dose- and time-dependent in MG-63 cells. In contrast, secreted ADAMTS-2 protein was increased only 1.4-fold with 1,25-dihydroxyvitamin D3. Finally, 1,25-dihydroxyvitamin D3 in the presence of ascorbate increased levels of secreted ADAMTS-2 1.9-fold over ascorbate treatment alone, which did not appreciably change ADAMTS-2 expression. These data indicate that the regulation of ADAMTS-2 is coupled with the synthesis of type I procollagen through 1,25-dihydroxyvitamin D3 signaling and may involve translational or posttranslational control.

It is well known that the imbalance between epithelial cell growth and inhibitor factors may cause human epithelial cancer. Over-expression of the epidermal growth factor receptor(EGFR) has been implicated in the development of oral squamous cell carcinoma. ZD1839 inhibits selectively the EGFR tyrosine kinase activity and is clinically used for cancer patients. However the mechanisms by which it exerts its anti-tumor activity remains unclear. This study attempted to determine the mechanisms underlying the effects of ZD1839 on the cellular level and to characterize the effects of ZD1839 with regard to human oral squamous cell carcinoma(OSCC) cell growth. The YD-10B and YD-38 cell lines established from OSCC in the department of Oral Pathology, Yonsei University College of Dentistry and ZD1839(Iressa) were used for this study. The inhibition of cell proliferation induced by ZD1839 was reversible and the lowest dose of ZD1839 that produced statistically significant growth inhibition in YD cell lines were 0.1 μM. The delay in cell cycle progression was induced by 0.1 μM of ZD1839 treatment after 24 hr. This reduction in cell proliferation and cell cycle delay were associated with up-regulation of the cyclin dependent kinase inhibitor(CDKI), P21CIP1/WAF1 and P27KIP1. Reduced expression of cyclin D1 was also observed after treatment with ZD 1839 to YD-38 cells but not to YD-38. The present results suggest that the antiproliferative effects of ZD1839, in vitro was associated with degradation of cyclin D1, which may be used as a possible indicator of a high cell sensitivity to ZD1839.

The aim of this study was to investigate the kinematics of young adults during descent ramp climbing at different inclinations. Twenty-three subjects descended four steps at four different inclinations (level, -8˚, -16˚, -24˚). The 3-D kinematics were measured by a camera-based Falcon System. The data were analyzed using one-way ANOVA and the Student-Newman-Keuls test. The kinematics of descent ramp walking could be clearly distinguished from the kinematics of level walking. On a sagittal plane, the ankle joint was more plantar flexed at initial contact with -16˚/-24˚ inclination, was decreased in the toe off position with all inclinations (p<.001),and was decreased at maximum plantar flexion during the swing phase (p<.001). The knee joint was more flexed at initial contact with the -24˚ inclination (p<.001), was more flexed in the toe off position with all inclinations (p<.001), and was more flexed at minimum flexion during stance phase and at maximum flexion during swing phase with -16˚, -24˚ inclination (p<.001). The hip joint was more flexed in the toe off position with -16˚, -24˚ inclination and was deceased at maximum extension during stance phase with -16˚, -24˚ inclination (p<.05). In the frontal plane, the ankle joint was more everted at maximum eversion during stance phase with -16˚, -24˚ inclination (p<.01) and was decreased at maximum inversion during swing phase with -16˚, -24˚ inclination (p<.01). The knee joint was more increased at maximum varus during stance phase with -16˚, -24˚ inclination (p<.001). The hip joint was deceased at maximum adduction during stance phase with -24˚ inclination (p<.05). In a horizontal plane, only the knee joint was increased at maximum internal rotation during stance phase with -24˚ inclination (p<.05). In descent ramp walking, the different gait patterns occurred at an inclination of over 16˚ on the descending ramp in the sagittal and frontal planes. These results suggest that there is a certain inclination angle or angular range where subjects do switch between level walking and descent ramp walking gait patterns.

Epitheli a l mesenchymal interaction(EMl) is well known to be essential in eznbryonic deve]opment. wound hea]jng a nd ca rci nogenes is. Th is study was a i med to design in vi tro model for the investigation of protein analysis in epithe li al a ncl mesenchyma l i nteract ion(EMI) . This stucly usecl oral squamous cell carcinoma cell line(YD-lOB) . 1'0 investigate the clifference 0 1' protei n ex press ion of cancel‘ cells influencecl by variable in vitro conditions. three different models were des ig necl ; Collagen gel- basecl ca ncer cell culture model devoid of fibroblasts(C) , Direct coτulture moclel(M2) composed of ca ncer cells beneath co ll agen gel embeclded with Swiss 31'3 fibroblasts ‘ and Indi rect co-culture model(Ml) with collagen layer betwecn cancel‘ cells and collagen gel with f lbroblasts Two-dimensional electrophoresis was performed to compa re t he diffe r ence of protein express ion pattern of ca ncer cells aznong three znodel systems. Protein identification was done by MALDI-TOF. As res ults ‘ pl'O te in express ion pat tem of cancel' cells was quite different between znonolayer cul ture and coll agen gel based cultu re. Aclditiona ll y. protein expression was different between culture models with fi broblasts and without fibroblasts a ncl between ind irect contact and direct contact of two cell types ‘ Among differentia l prot ei n spots. catheps in D WäS iuenLifï ed by MALDl• TOF Cathepsin D exprcssion was increased from C model to 11띠 and M2 model by West em blott ing. suggest ing that cathe psi n D expression may be activated by direct and indirect stimulation of stromal fï broblas ts F' rom these resul ts ‘ these models could be appropriate for EMI study and cathepsin D mi ght be incluced by fi broblasts s timulation

동체시력 (Dynamic Visual Acuity) 은 물체나 관찰자가 움직이는 상태에서 사물을 볼 수 있는 능력을 익미한다. 즉， 동체시력은 안구운동계의 전반적인 능률 (efficiency) 과 관계가 깊고， 또한 측정시스템의 구성에 따라 측정에 영향을 줄 수 있다. 따라서 시표크기에 따라 동체시력이 차이가 날 수 있다. 본 연구는 일반인 (1 ，Il)군과 운동선수 (IIl， N)군을 각각 두꾼 으로 나누어 란톨트 (Land이t) 고리 시 표크기 를 2.1 cm, 3.71 cm로 탈리하여 동체시력을 측정하였다. 시표크기를 2.1 cm 측정한 결과 일반인(1)군의 평균 동체 시 력 은 85.71 :t 15.05 deg/sec 였으며 , 운동선수( IIl)군은 1oo.63 :t 21.75 deg/sec 였다. 시표크기를 3.7cm로 측정한 결과 일반인(Il)군의 평균동체시력은 136 :t 7.19 deg/sec 였 으며 운동선수군 (N) 은 149 :t 14.20 deg/sec 였다. 일반인군이나 운동선수군에서 같은 정도의 동체시 력 상승이 있으나， 측정 속도로 볼 때 운동선수군이 시표크기에 많은 영향을 받는 것으로 나타났다 이는 경기력과 상관성이 있는 것으로 알려진 운동선수 의 동제시력을 측정힐 때 시표크기에 유의해야함을 보여준다. 본 연구는 동체시력 연 구에 관련된 기초 자료로 앞으로 동체시력을 연구하는데 도융을 줄 수 있을 것으로 기대된다.

양안시 이상의 문제륜 연구하기 위하여 팔절 검사와 양안시 검사룹 실시하였다- 편 안한 양안시틀 위해서 조절과 폭주의 균형이 중요한데， 조절과 양안 λl 에 문제가 있는 대상자들은 굴절 이상 교정 외에도 다른 추가적인 처방이 필요하였다. 그 증 폭주 파 다와 폭주 부족의 문제플 가지고 있는 2 명을 대상자륜 정하여 완전 교정된 안경을 처방하고 4주간 시기능 훈련을 실시하였다 4주 후 근업시 환자뜰의 불편감은 많이 해소되었으며 타각적 검사값들도 개선되었 다 시기능 훈련이 폭주 여력뿐만 아니라 개산 여력을 증가시키는 데또 효과가 있었 으므로， 임상에서도 양얀시 이상의 치료에 적극적으로 적용하고， 향후 연구플 동해 다양한 양얀시 이상 치료에 시도해도 좋온 결과가 있을 것으로 판단된다.

자각식 꿀절검사를 실시하기 위한 예비검사로 자동굴절계가 겸영법을 대신하여 널 리 사용되고 있으며， 정확도가 높지만， 특히 어린 나이에서 측정오차약 한 가지 요인 으로 보고되는 조절의 영향을 알아보기 위하여， 일산 거주 초중고 학생 391 명(초등학 교 저 학년 95 명 7.45 :t 0 ，61 세， 초등학교 고학년 87 명 10.46 :t 0.60세， 중학생 120 명 12.86 :t 0 ，34세， 고등학생 89 명 14.76 :t 0.55 세)을 대상으로 현성 빚 조절마비 자동굴절 검사 (Topcon KR-7100P) 를 실시하였다. 현성 굴절상태에서 측정한 자동굴절검사값과 조절마비 자동굴절검사값의 차이를 M, Jo 및 J45 성분의 벡터로 전환하여 분석하였다， M 성분의 차이는 초등학교 저학년 에서 가장 크게 나타났고， 나이 증가에 따라 감소하는 경향을 보였으며 각 연령군 사 이에서 유의한 차이릎 보였다 (F 二27.03, p = 0,0000). 그러나， Jo 성분 맞 J45 성분의 차 이는 각 연령군 사이에서 유의한 차이가 없었다 (F = 0.70, p = 0.55 및 F 二0.31 ， p = 0.82) 각 연령군에서 현성 자동굴절검사값과 조절마비 자동굴절검사값의 M 성분 차이는 굴절이상도와 유의한 상관성을 보였으며(초등학교 저학년 R 二-0 ， 33 ， p < 0.0001 ; 초등 학교 고학년 R = -0.41, p < 0.0001 ; 중학생 R = -0.29, p < 0.0001 ; 고등학생 R = -0.14, p = 0.06), 근시군과 바근시군에서 M 성분의 평균 차이가 유의한 것으로 나타났다(초 등학교 저 학년 t = -4.75, p = 0.0000 ; 초등학교 고학년 t = • 6.45, p = 0.0000 ; 중학생 t = -4.48, p = 0.0001 ; 고등학생 t = -3.41, p = 0.0008). 이상의 결과로부터 현성 자동꼴절검사 결과는 조절로 인한 측정오차가 유발될 수 있고， 특히 나이가 아리고 근시도가 낮거나 정시 또는 원시성인 경우 측정오차가 상 대적으로 높은 것으로 나타났으므로， 굴절이상을 교정하기 위한 검사 과정에서 자동 굴절검사 결과를 해석할 때 조절로 인한 오차 가능성이 고려되어야 할 것이다.

Bending and tensile properties of 2D cross-ply C/C composites with processing heat treatment temperature (HTT) are evaluated. C/C composites used are made from two types of PAN based T700 and M40 carbon fibers with phenolic resin as carbon matrix precursor. Both the types of composites are heat treated at different temperatures (ranging from 750 to 2800℃) and characterized for bending and tensile properties. It is observed that, real density and open porosity increases with HTT, however, bulk density does show remarkable change. The real density and open porosity are higher in case T-700 carbon fiber composites at 2800℃, even though the density of M40 carbon fiber is higher. Bending strength is considerably greater than tensile strength through out the processing HTT due to the different mode of fracture. The bending and tensile strength decreases in both composites on 1000℃ which attributed to decrease in bulk density, thereafter with increase in HTT, bending and tensile strength increases. The maximum strength is in T700 fiber based composites at HTT 1500℃ and in M40 fiber based composites at HTT 2500℃. After attending the maximum value of strength in both types of composite at deflection HTT, after that strength decreases continuously. Decrease in strength is due to the degradation of fiber properties and in-situ fiber damages in the composite. The maximum carbon fiber strength realization in C/C composites is possible at a temperature that is same of fiber HTT. It has been found first time that the bending strength more or less 1.55 times higher in T700 fiber composites and in M40 fiber composites bending strength is 1.2 times higher than that of tensile strength of C/C composites.

We studi ed the difTerential elTect of vitamins A, C, U. and E on normal human 이 al keratinocyte(NHOK) , HPV-16 E6E7 immor talized human oral keratinocyte(1HOK) , Oncogene transfected HPV-16 immortalized ce1ls(OTOK) , and two ol'al sq ua mous cell line(HNSCC30‘ HNSCC31) according to carcinogenesis stage. The vitamin effect was evaluated by morphology. ce ll viabi lity. a nd orgnaotypic culture Vitamin A has a greater negative effect on growth for all NHOK IHOK HNSCC. es pec ially N-Ras t rans fected IHOK, Vitamin D & E revealed no significant cell activity on NHOK lHOK, ad OTOK Vitamin C was found increased cell viability to IHOK and OTOK 1n primary oral squmaous cell ca rcino ma (HN30 ). vitam in 0 and C showing increased cell growth , but vitamin E showing no effect 1n metastatic oral squamous cell ca rcinoma(HN31), vitamin C has prol iferative effect , but vitamin 0 & E has anti-proliferative effect Vitamin A t reated normal a nd ma lignant ce1ls by organotypic cu lt ure. showed reduction of epithelial layer and in vasion to connective tissue. , especia lly in 1HOK & oncogene-transfected 1HOK, 1n conclusion. three-dimensional culture sys tem may be useful as a model to acess the efficiency of agents such as a1l trans retinoic acid can preventing progression of these premaligant lesion to maligant oral carcinoma(ch emopreventive agent) .

Recently, Vendor Managed Inventory(VMI) has been commonly recognized as one of the supply chain application that delivers clear value to the sectors of electic & electronic components. VMI is a process in which a supplier generates orders for its distributor based on demand information sent by the distributor. VMI is providing the benefits of smoother demand, lower inventories(work in process, safety stock) and reduced costs. This study focused on improvement of safety level inventory efficiency by VMI. The results indicated that VMI allowed the company to serve its customers more surely and efficiently.

최근에 수행되고 있는 중력 탐사는 고분해능의 중력계와 GPS(Global positioning system)를 통한 정밀한 측정과 측지가 이루어지고 있다. 중력탐사에서 모델링과 역산의 기술은 많은 발전이 있어왔지만, 중력자료처리는 거의 변화가 없었다. 통상적인 정밀한 중력 자료 보정을 통한 부우게이상은 측정점의 고도에서 기준면까지의 물질의 영향을 일정한 밀도를 이용해 제거해 버리기 때문에 측정점 바로 하부의 이상체에 의한 영향을 상당히 왜곡시키게 된다. 본 연구에서는 탐사 지역의 지형을 DEM(Digital Elevation Map) 자료와 Multiquadric equation을 이용하여 실제 지형과 유사한 Multiquadric surface를 자동적으로 구성하고, 이를 블록화 함으로써 보정의 대상이었던 기준면 상부에 대한 밀도를 탐사 지역의 지질 정보와 지형을 포함하는 역산을 통해 수치적으로 계산하였다. 이러한 지형을 포함한 역산 방법을 3차 원중력지형역산(3DGTI; 3-D Gravity Terrain Inversion)이라 한다. 이 연구의 효율성을 검증하기 위하여 주변암과 밀도차가 존재하는 관입지역에 대한 모델을 구성하고 적용한 결과 기존의 부게 보정 방법을 적용한 부게 이상도에 비해 자료의 왜곡이 감소하는 효과를 얻을 수 있었다. 이를 통하여 지형 역산을 통한 객관적인 부게 밀도의 결정과 부게 보정시 실제의 수평적인 밀도 변화를 반영함으로써 기존의 문제점을 보완하였다. 게다가, 3DGTI로부터 얻어진 밀도분포는 지형의 윤곽을 그대로 표현하고 있어서 보다 실질적인 지질을 보여준다고 하겠다. 이 방법을 화강암체가 관입하고 있는 마산·창원 일대에서의 중력 탐사 자료에 적용해본 결과 기존 방법보다 관입 화강암체의 위치와 그 규모를 알아내는데 더 효과적이었다. 따라서, 수평적인 밀도 변화가 뚜렷하게 존재하는 지역의 경우, 새로운 중력 자료 처리 방법이 기존의 부게 보정에서 발생하였던 문제점을 해결함으로써 천부의 분해능을 높이고, 심부의 밀도 분포도 좀더 정확하게 계산할 수 있으리라 생각된다.