Nimodipine이 쥐의 뇌경색에 미치는 영향

의학과/박사[영문] [한글] 뇌혈류의 감소로 발생되는 허혈성 뇌질환은 비가역적인 뇌손상의 흔한 원인으로 알려져 있으며 허혈성 손상으로 부터 뇌를 보호하는 것은 중요한 임상과제로 생각된다. 허혈성 뇌손상은 국소허혈 후에 오는 지연성 저관류와 비가역적 세포손상을 초래하는 세포막변성 에 의해서 야기된다고 하며 칼슘이온은 두가지 뇌허혈의 병태생리 기전에 중요한 역할을 한다고 알려져 있다. 칼슘통로 차단제는 허혈성 뇌질환의 가능한 치료제로서 생각되어 진 다. 칼슘통로 차단제 중의 하나인 nimodipine은 dihydropyridine 유도체로서 강력한 혈관 확장 작용이 있으며 뇌혈관에 선택적으로 작용하는 것으로 알려져 있다. 저자는 쥐의 국 소뇌허혈 모델을 대상으로 nimodipine을 투여하여 nimodipine의 뇌허혈에 대한 효과를 보 고자 하였다. 중대뇌동맥 폐색 1시간, 2시간 그리고 6시간 후에 nimodipine 혹은 생리식 염수를 투여하였고 폐색 24시간 뒤에 시행한 신경학적 검사와 병리학적 소견을 통하여 ni modipine 투여군과 중대뇌동맥 폐색만 시행한 대조군 및 생리식염수 투여군을 서로 비교 하여 다음과 같은 결과를 얻을 수 있었다. 1. Nimodipine 투여군은 생리식염수 투여군 및 대조군보다 뇌경색의 면적이 약 5∼11% 감소 되었다. 2. 폐색 1시간 후의 nimodipine 투여군은 폐색 2시간 및 6시간 후의 nimodipine 투여군 보다 뇌경색의 범위가 작았으나 통계학적 의의는 없었다. 3. 대조군과 생리식염수 투여군 간에는 뇌경색 비율의 뚜렸한 차이가, 없었다. 4. Nimodipine 투여군은 생리식염수 투여군 및 대조군보다 신경학적 소견이 양호하였다 . 이상의 결과로 보아 뇌허혈시 nimodipine은 신경학적 소견을 호전시키고 뇌경색의 범위 를 감소시킬 수 있다고 생각된다. Nimodipine의 작용기전은 확실히 알려wu 있지 않으나 n imodipine은 뇌혈류를 증가시키거나 흑은 신경세포에 직접 작용하여 허혈에 의한 뇌손상 으로 부터 뇌를 보호한다고 생각된다. The Effects of Nimodipine on Focal Cerebral Ischemia in Rats Se Hyuck Park Department of Medical Science The Graduate School, Yonsei University (Directed by Professor Kyu Chang Lee, M.D.) Brain ischemia due to a critical reduction in cerebral blood flow is a well recognized and common cause of irreversible brain damage. Therefore protecting the human brain from ischemic damage is an important clinical problem. Two major factors influence the sequelae of cerebral ischemic injury : the delayed hypoperfusion that occurs after focal ischemia and membrane failure that leads to irreversible cell injury. Calcium ions play a major role in both pathophysiological mechanisms. And so calcium channel blockers are a logical choice for investigation as possible therapeutic agents for the treatment of cerebral ischemia. Nimodipine, a dihyropyridine derivative, is one of the most potent calcium channel blocking agents with a selective action on the intracranial vessels. The present study was designed to test the effects of nimodipine on focal cerebral ischemia in rats. At 1, 2 or 6 hours after occlusion of the middle cerebral artery (MCA), rats were treated with either nimodipine or saline. Neurological and pathological evaluation was performed at 24 hours after occulusion. Neurological outcome was better in nimodipine-treated rats and the size of the infarcted area was statistically smaller in rats treated with nimodipine 1, 2 or 6 hours after occlusion (p<0.001, p<0.001,p < 0.001 respectively) when compared with control rats (MCA occlusion only) or saline-treated rats. The results show that nimodipine improves neurological outcome and decreases the size of the infarcted area after ischemic insult. The mechanism of action of nimodipine is not fully understood but nimodipine could influene cerebral postischemic changes by improving blood flow and/or by a direct action on neurons.restrictio

Clinical Observation of the Chronic Subdural Hematomas

의학과/석사[영문] [한글] 1976년 1월부터 1983년 9월까지 연세의대 신경외과학 교실에서 치험한 만성경뇌막하혈 종 103예에 대한 임상적 고찰, 특히 각 수술방법에 대한 결과를 서로 비교하여 다음과 같 은 결과를 얻었다. 1. 연령분포는 41세부터 60세까지가 49명 (47.5%)으로 가장 많았고 40대 이상에서는 74 명 (71.8%)이었다. 남녀비는 남자가 87명(84.5%), 여자가 16명(15.5%) 이었다. 2. 유발인자에서는 두부외상력이 있는 경우는 72명(79.6%)이었고 알콜중독자는 13명(12 .6%)이었으며 지주막낭종 1예, 지주막낭종 및 뇌수종으로 낭종복강간도관술후 상태 1예 및 만성골수성백혈병 1예가 있었다. 3. 임상증세 및 신경학적 소견을 보면 두통이 82예 (77.6%)로서 가장 많았으며 마비증 상이 46예 (44.7%), 의식장애 및 안저소견상 유두부종 같은 유두부 변화가 각각 45예(43. 7%) 및 44예(42.7%)였다. 그 외 구토, 동공부동증, 경련, 언어장애 및 시각증상이 있었다 . 4. 뇌전산화단층촬영이 진단 및 수술방법의 결정과 예후판정에 중요한 역할을 하며 혈 종의 밀도를 볼 때 저밀도혈종이 32예(43.3%), 동밀도혈종 28예(37.8%), 고밀도혈종 10예 (13.5%)였고 그외 혼합밀도는 4예 (5.4%)의 혈종에서 볼 수 있었다. 수술후 3주내에 시행 한 뇌전산화단층촬영에서의 뇌팽창율은 나이가 들수록 감소하여 40대 이상에서는 80% 이 하로 감소했다. 5. 혈종의 발생부위는 좌측이 47예 (45.6%), 우측이 43예(41.8%)로서 큰 차이는 없었고 양측성은 13예 (12.6%)가 있었다. 단순폐쇄배출술시 혈종의 배출량은 수술 당일날 가장 많아 49%에 달했고 수술 다음날 33%로서 수술후 제 2일까지 전체의 95%가 배출되었다. 6. 치료방법으로 102예에서는 수술적 방법으로 치료했고 나머지 1예에서는 steroid와 L asix를 사용하여 비수술적으로 치료했다. 수술방법으로는 32예에서는 단순폐쇄배출술을, 31예에서는 두개천공술및 개방배출술을, 1차 수술후 다시 혈종이 형성된 2예를 포함한 31 예에서는 성형적 개두술 및 혈종막 제거술을 시행했고 나머지 10예에서는 두개골 제거술 후 혈종막을 제거했다. 수술법을 서로 비교한 결과 단순페쇄배출술이 일차적인 치료법으 로 생각된다. 그러나 일차 수술후 혈종이 다시 고인 경우, 고형성 혈종인 경우 및 뇌팽창 이 잘 안되어 경막하강이 오랫동안 막히지 않는 경우에는 개두술 후 혈종막 제거술을 시 행해야 한다. CLINICAL OBSERVATION OF THE CHRONIC SUBDURAL HEMATOMAS Se Hyuck Park Department of Medical Science The Graduate School Yonsei University (Directed by Prof. Kyu Chang Lee, M.D.) One hundred three chronic subdural hematomas were treated from January, 1976 to September, 1983, of which 102 cases were operated and 1 case was treated with medication. The clinical analysis and surgical results were summerized as follows. 1. The chronic subdural hematomas were the most common in the 5th and 6th decade (47.5%) and prominent over 5th decade(71.8%). The proportion of males(84.5%) was much greater than females (15.5%) 2. 79.6% of crises had previous head injuries and 12.6% were chronic alcholics. One case was associated with the arachnoid cyst in the middle cranial fossa and another one case in the postoperative state of cystoperitoneal shunt due to hydrocephalus and arachnoid cyst in the supratentorial and infratentorial area. One case was under management of chronic myelocytic leukemia . 3. The common symptoms were headache(79.6%), motor weakness(44.7%), alternation of consciousness(43.7%), change of fundus such as papilledema (42.7%) and vomiting (35.0%). In addition there were pupillary inequality, seizure, speech disturbance and visual symptoms. 4. Brain CT scan was the most effective and noninvasive diagnostic tool for detecting chronic subdural hematoma and important in planning operative intervention and evaluation of prognosis. Chronic subdural hematomas presented in 4 different forms in CT scans: hypodense subdural hematoma(43.3%), isodense subdural hematoma(37.8%), hyperdense subdural hematoma(13.5%)and mixed density subdural hematoma(5.4%). CT scanning was the most accurate method of determining the age of a chronic subdural hematoma. The cerebral expansion rate (reduction in diameter of the subdural space) decreased with aging and it was less than 80% in average over 5th decade within postoperative 3 weeks. 5. The right sided chronic subdural hematomas were 45.6%and the left were 41.8% with bilaterality in 12.6%. Average amount of chronic subdural hematomas drained daily in 32 patients treated with simple burr-hole and closed-system drainage were as follows: 49% on the duty of operation, 33% on POD 1 and 13% on POD 2, and almost all of the hematoma was drained out within two days doter surgery. 6. In 103 patients, operation were performed in 102 patients, and the other one patient was treated conservatively. thirtytwo patients were underwent simple burr-hole and closed-system drainage and in 1 patient craniotomy and and membranectomy was necessary. The blood bags were used in 31 patients and Hemovac in 1 patient. Four patients were operated under local anesthesia. thirtyone patients were treated with burr holes and open drainage and one patient required craniotomy and membranectomy. In 31 patients underwent craniotomy and membranectomy. Craniectomy and membranectomy were performed in 10 patients. One patient died of hypertensive intracerebral hematoma 1 developed during operation under local anesthesia and another 1 patient was unchanged following simple burr-hole and closed-system drainage. Three patients were unchanged or deteriorted after burr holes and open drainage and 8 patients following craniotomy and membranectomy. The results of simple burr-hole and closed-system drainage were better than other methods. Simple burr-hole and closed-system drainage is today's most rational approach to the chronic subdural hematoma in children beyond the infant period and in adults. Craniotomy, membranectomy and craniectomy should be reserved for instances :the subdural recollection, failure of the brain to expands solid hematoma and extensive swelling of white matter subjacent to the hematoma.restrictio

자기공명 영상법에서의 소음의 분석 및 이의 응용

학위논문(박사) - 한국과학기술원 : 전기및전자공학전공, 2000.2, [ iv, 91 p. ]Magnetic Resonance Imaging has been extensively applied to many areas of the diagnostic imaging and brain unctional imaging. But, one of the important obstacle in the use of MRI techniques has been the acoustic noise generated in MRI scanners, both in patient scanning as well as in many areas of the neuroscience research such as fMRI (functional MRI). Besides physical discomfort, acoustic noise acts on some negative effects to the study of fMRI by the decrease of activation or unwanted response in auditory sensory portions of the brain. Although a number of ideas have been suggested to reduce or eliminate acoustic noise, the progresses by them have been slow due to the basic role of gradient pulsing in MRI. The gradient pulsing means the switching of the current flows through the gradient coils in the main magnetic field of MRI scanners during imaging and it causes to the heavy and fast vibrations of the gradient coil. To solve this acoustic noise problem in MRI, the systematic analyses of acoustic noise behaviors and their characteristics in several MRI systems were studied firstly. In comparison, data from both a commercial MRI scanner (GE Signa 1.5 T) as well as a research-type MRI scanner (KAIS 2.0 T) are used. By the results of the analyses of the acoustic noise pattern in MRI, the DC gradient concept was introduced to the imaging technique. Because it did not use the gradient switching, it generates no Lorentz force in all directional coils. From the application of DC gradient, new imaging pulse sequences such as Silent Spin-Echo sequence using a rotating DC gradient and Silent FM DANTE sequences, are explored. And, to show other possibility to acoustic noise reduction using the circular type z-directional gradient characteristic, the acoustic noise reduction effect in fMRI dependent on imaging views of GE EPI was studied. From the result of fMRI studies using a typical commercial whole-body MRI scanner (GE Signa 1.5T), the acoustic noise level was able...한국과학기술원 : 전기및전자공학전공

Method and apparatus for encoding image, and method and apparatus for decoding image based on regularization of motion vector

영상의 부호화 방법 및 장치, 복호화 방법 및 장치가 개시된다. 영상 부호화 방법은 인접한 블록들을 병합한 병합 블록의 움직임 벡터, 병합 블록에 포함된 블록들의 움직임 벡터, 주변 블록들의 움직임 벡터에 기초하여, 병합에 의한 움직임 벡터의 균일화 정도에 대비한 움직임 예측 오차의 변화량을 획득하고 획득된 변화량에 기초하여, 병합 블록들 중 변화량이 가장 작은 병합 블록을 결정하고 결정된 병합 블록에 포함된 블록들의 병합 여부를 결정한다

Method and apparatus for smoothing motion vector

참조 영상을 이용하여 현재 영상의 적어도 하나의 블록에 대한 움직임 벡터를 각각 획득하고, 현재 블록의 움직임 벡터 및 상기 현재 블록에 인접한 적어도 하나의 블록의 움직임 벡터 중 적어도 하나에 기초하여 상기 현재 블록에 대한 후보 움직임 벡터를 획득하고, 현재 블록에 속한 화소들의 그래디언트 값에 따라 현재 블록에 대한 임계치를 결정하고, 결정된 임계치에 따라 현재 블록에 대한 움직임 벡터를 결정하는 움직임 벡터를 평활화하는 방법이 개시된다

모션 벡터 정규화를 기반으로 한 화상 부호화 방법과 장치와 화상 복호화 방법과 장치

Provided are an image encoding method and apparatus, and an image decoding method and apparatus. The image encoding method includes: obtaining a variation of a motion estimation error with respect to a homogeneity degree of a motion vector according to mergence, based on a motion vector of each of merged blocks obtained by merging adjacent blocks, motion vectors of the adjacent blocks included in each of the merged blocks, and motion vectors of neighboring blocks of each of the merged blocks; and determining, based on the obtained variation, a merged block having a smallest variation from among the merged blocks and whether to merge the adjacent blocks included in the determined merged block