Thrombolytic Effects of the Snake Venom Disintegrin Saxatilin Determined by Novel Assessment Methods: A FeCl3-Induced Thrombosis Model in Mice.

Saxatilin, a novel disintegrin purified and cloned from the venom of the Korean snake Gloydius saxatilis, strongly inhibits activation and aggregation of platelets. Glycoprotein (GP) IIb/IIIa receptor antagonists can resolve thrombus, so saxatilin might also have thrombolytic effects. We investigated the thrombolytic effects of saxatilin in mice using a ferric chloride-induced carotid arterial thrombosis model. Thrombotic occlusion and thrombus resolution were evaluated quantitatively by measuring blood flow in the carotid artery with an ultrasonic flow meter and calculating the degree of flow restoration on a minute-by-minute basis; results were confirmed by histological examination. Saxatilin dissolved thrombi in a dose-dependent manner. Saxatilin at 5 mg/kg restored blood flow to baseline levels. As saxatilin dose increased, time to recanalization decreased. A bolus injection of 10% of a complete dose with continuous infusion of the remaining dose for 60 minutes resulted in effective recanalization without reocclusion. The thrombolytic effect of saxatilin was also demonstrated in vitro using platelet aggregometry by administering saxatilin in preformed thrombi. Bleeding complications were observed in 2 of 71 mice that received saxatilin. Fibrin/fibrinogen zymography and platelet aggregometry studies indicated that saxatilin does not have fibrinolytic activity, but exerted its action on platelets. Integrin-binding assays showed that saxatilin inhibited multiple integrins, specifically α2bβ3 (GP IIb/IIIa), α5β1, αvβ3, αvβ1, and αvβ5, which act on platelet adhesion/aggregation. Saxatilin inhibited multiple integrins by acting on platelets, and was safe and effective in resolving thrombi in mice.ope

베타-2-마이크로글로블린 유래 펩타이드 (58-67]의 아밀로이드 형성과 이를 활용한 베타-2-마이크로글로블린의 제거 연구

Thesis(masters) --서울대학교 대학원 :협동과정 바이오엔지니어링전공,2010.2.Maste

Diagnostic significance of myelo-enhanced computerized tomography(MECT) in spinal stenosis

의학과/석사[한글] 척추관협착증은 척수강, 측부와, 추간공 및 추간공 외에서의 골구조나 연부조직의 비후등 모든 형태의 협착으로 인하여 야기되는 신경근의 압박증후군을 의미하며, 진단은 비특이적인 임상 증상과 이학적 소견으로 방사선학적 진단의 비중이 크게 기여하여왔다. 이에 저자는 1991년 1월부터 1993년 12월까지 원주의료원 및 세브란스병원 정형외과에서 치험한 척추관협착중 환자중, 척수강조영술 및 전산화단층찰영(Computerized tomography; CT)를 모두시행하고, 수술을 받은 40례의 환자를 대상으로 본 연구를 시행하여 다음과 같은 결과를 얻었다. 1) 척수강조영술 소견으로는, 모래시계모양 양측결함이 15례(37.5%), 완전차단 14례(35%)로 대부분을 차지했다. 2) MECT(Myelo-enhanced computerized tomography)상 협착의 부위별 빈도는 중앙부, 측부 및 추간공협착이 동반된 혼합형 척추관협착증이 19례(47.5%)로 가장 많았으며, Amoldi의 분류에 따른 척추관협착증 분류상 심한 퇴행성변화와 동반된 요추부의 척추관협착증이 22례(55%)로 가장 많았다. 3) MECT상 이환 부위별 빈도는 단일병소 18례(45%), 이중병소 16례(40%), 삼중병소 6례(15%)의 순이었으며, 단일병소중 가장 많이 이환된 부위는 제 5요추와 제 1천추사이의 12례(30%)로 가장 많았다. 또한, 척추관협착증이 주가되어 동반된 질병별 빈도는, 추간판탈출증이 14례(35%), 척추전방전위증이 11례(27.5%)의 순으로 나타났다. 이상의 결과와 수술 소견에 따른 진단적 정확성은 척수강조영술 83%, MECT 97.5%로, MECT가 척추관협착증에서 월등히 높은 진단적 정확성을 보였으며, 또한 협착의 유형, 정도 및 범위에 관한 정보를 제공함으로써, 감압적 추궁판 절제술의 범위를 결정하는데 큰 도움을 주었다. [영문] Lumbar spinal stenosis may be defined as any type of narrowing of the spinal canal, nerve root canals or intervertebral foramina. It may be local, segmental or generalized and may be caused by the encroachment of bone or soft tissue. The narrowing may involve the bony canal alone or the dural sac or both. Myelo-enhanced computerized tomography(MECT) has been accepted as especially useful diagnostic method for spinal stenosis after its application in the orthopedic fields. The goal of this study was to analyze the diagnostic accuracy and sensitivity of MECT and to determine the prevalance of stenosis in various legions of lumbar spine. During the period of 3 years, from January 1991 to December 1993, 40 cases of lumbar spinal stenosis were analyzed, all of whom took myelography, computerized tomography and surgical treatment. The results of the study were as follows: 1. The myelographic findings were, respectively, hourglass bilateral defect 15(37.5%), complete block 14(35%) and unilateral focal defect 5(12.5%). 2. The most prevalent form of spinal stenosis was the combined central-lateral-foraminal stenosis (47.5%) and the degenerative change in the lumbar spine was the principal etiologic factor (55%) by Arnoldi classification. 3. The involved levels were as follows: one level 18(45%), two levels 16(40%) and three levels 6(15%). And among single level, the most frequent level was L5-S1 intervertebral space(30%). The diagnostic accuracies according to operative findings and above results were 83% by myelography and 97.5% by MECT. The MECT showed absolutely superior to myelography or CT and it was especially useful in lateral stenosis and multi-level stenosis.restrictio

On the term structure models of interest rate : overcoming the HJM framework

Thesis (master`s)--서울대학교 대학원 :수학과,1999.Maste

시장가격에 내재된 금융이론

Thesis (doctoral)--서울대학교 대학원 :수리과학부,2003.Docto

ELECTROPORATION DEVICE COMPRISING 3-DIMENSIONAL MICROELECTRODES AND METHOD OF MANUFATURING THE SAME

본 발명은, 적어도 하나 이상의 분지 및 상기 분지에 연결된 적어도 2개 이상의 가지를 각각 갖는 3차원의 제1 전극부 및 제2 전극부를 포함하는 전기천공장치 및 이의 제조방법에 관한 것으로, 본 발명의 전기천공장치는 세포 내 물질전달효율을 높이고, 세포의 생존율을 높일 수 있다

한국거머리에서 분리한 단백질분해효소 억제제, 거머린의 이황화 결합에 관한 연구

학위논문(석사) - 한국과학기술원 : 생물과학과, 1998.2, [ v, 37 p. ]Guamerin, a humam leukocyte elastase inhibitor from the Korean leech Hirudo nipponia is composed of 57 amino acid residues with ten cysteines. Disulfide bonds between two cystein residues were analyzed by biochemical methods. Thermolysin digestion of guamerin revealed that it had two domains containing two and three disulfide bonds, respectively. The N-terminal domain was revealed to have Cys1-Cys3 bond(disulfide bond between the first cysteine and the third cysteine) and Cys2-Cys4 bond. The disulfide bond pattern of the C-terminal domain was one of ``Cys5-Cys8, Cys6-Cys9 and Cys7-Cys10`` or ``Cys5-Cys8, Cys6-Cys10 and Cys7-Cys9`` patterns, that was not completely determined yet. Among the five disulfide bonds, there were two weak disulfide bonds more easily modified by 4-vinylpyridine at pH8.0. Likewise, recombinant guamerin expressed in the yeast Pichia pastoris and guamerin II, a serine protease inhibitor from another Korean leech, Whitmania edentula were revealed to have identical disulfide bond pattern and characteristics with guamerin. Furthermore, their disulfide bond patterns were consistent with those of hirustasin and antistasin, another serine protease inhibitors from other leech species, of which three dimensional structures were already determined by X-ray crystallography.한국과학기술원 : 생물과학과

A study on the subscriber loop interface for a PCM PBX system

학위논문(석사) - 한국과학기술원 : 전기 및 전자공학과, 1980.2, [ [ii], 72 p. ]PCM PBX System의 Subscriber Loop Interface에 대하여 연구 실험하였다. 먼저 PCM PBX System의 구성개요가 설명되었으며, Subscriber Loop Interface의 중요부분과 보조장치들이 고찰되었다. hybrid 회로는 isolation transformer와 연산증폭기를 이용한 active hybrid로 구성하여 이들의 특성이 측정되었으며, 각 보조 장치들을 제작한후 동작실험을 하였다. 위의 각 부분을 조합하였을때 전체회로가 PCM PBX System에서 만족스럽게 동작하는 것이 확인되었다.한국과학기술원 : 전기 및 전자공학과

구강점막의 창상치유에 대한 식나무(Aucuba japonica) 추출물의 효과

Aucuba japonica has variable pharmacological effects such as hepatoprotective, choleretic, hemodynamic, antimicrobial, and anti-inflammatory activities. This study was performed to investigate the effects of Aucuba japonica extract on oral wound healing. Aucubin was extracted from Aucuba japonica, and injected on either side of buccal mucosa of male mice. Artificial full thickness wounds were made on the site with 1.5 mm biopsy punch under sterile technique. The specimens had taken on day 1, 3, and 5 with 4 mm biopsy punch. Light microscopic examination and quantitative histologic analysis were performed for reepithelization, inflammatory cell infiltration. Reepithelization of the aucubin (0.1%) group was earlier than the control group. And the number of inflammatory cells of the aucubin group was lesser than the control group. In view of the results so far achieved, the aucubin extracted from Aucuba japonica may be useful for oral wound healing and it can be applied as a topical agent on the oral wound. Further research should be performed on the mechanism of aucubin on oral wound healing and proper formulation for effective topical agents