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      • 냉동 제대혈 세포의 체외 증폭

        김삼용,김철희,배광봉,김현수,박상준,김종숙,윤환중,조덕연 충남대학교 암연구소 1998 癌共同硏究所 硏究誌 Vol.2 No.1

        Background : Cord blood(CB), which has no HLA restriction, is an alternative to bone marrow for hematopoietic stem cell transplantation. The use of cord blood, however, is limited by the number of progenitor/stem cells necessary to reconstitute the older child or adult. Therefore, ex vivo expansion of CB could have tremendous impact on diverse clinical settings. We studied the ex vivo expansion of isolated population of CD34_(+) cells from cryopreserved CB cells. Methods : CD34 cells were isolated from cryopreserved CB mononuclear cells. Purified cells were cultured with various combinations of hematopoietic growth factors including erythropoietin(EPO), stem cell factor(SCF), granulocyte-colony-stimulating factor(G-CSF), gra-nulocyte, macrophage-colony-stimulating factor(GM-CSF), interleukin-1β(IL-1β), 1L-3, and IL-6. After 7, 10 or 14 days of culture, the fold increases of colony-forming unit- granu-locyte, macrophage(CFU-GM), burst-forming unit-erythroid(BFU-E), colony-forming unit-mix (CFU-Mix), and high proliferative potential colony-forming cell(HPP-CFC) were evaluated. Results : Ten-day culture with the combination of EPO, SCF, G-CSF, IL-1β, and IL-3 resulted in a median of 60-fold increase of CFU-GM, which was greater than those with the combinations of less than 5 growth factors. The addition of IL-6 or GM-CSF to this combination did not enhance CFU-GM expansion. Ten-day culture was significantly superior to 7-day culture for CFU-GM expansion. Prolongation of culture to 14 days, however, revealed decreased expansion of CFU-GM compared to 10 days. BFU-E and CFU-Mix were expanded to 2~5 folds in 7-day culture with the combination of EPO, SCF, and G-CSF. Further expansion was not achieved in 10-day culture and colonies disappeared in 14-day culture. HPP-CFC was expanded to a median of 7.5 folds in 7-day culture with the combination of EPO, SCF, G-CSF, IL-1β, IL-3, and IL-6. Neither 10-day or 14 day-culture enhanced expansion of HPP-CFU. Conclusion : Cryopreserved cord blood cells maintain ex vivo expansion potential. In our system, 10-day culture with the combination consisting of EPO, SCF, G-CSF, IL-1β, and IL-3 seems to be adequate for hematopoietic progenitor/stem cell expansion from cryopreserved cord blood cells.

      • 당뇨병성 합병증을 가진 환자에서 혈중 Erythropoietin 농도

        김동규,유기동,허광식,김상용,윤성호,조영신,권용은,김태원,김건영,정종훈,배학연 朝鮮大學校 附設 醫學硏究所 1998 The Medical Journal of Chosun University Vol.23 No.1

        연구 배경 : 고혈당성에 의한 산화환원반응 이상(가저산소증)이 조절 되지않는 당뇨병의 특징으로 혈관과 신경 기능에 대한 진성 저산소증의 효과와 유사하며, 당뇨 합병증의 병태생리에 중요한 역할을 한다. 고혈당이 있는 인슐린 비의존형 당뇨병 환자에서 인슐린 수준이 정상이듯이, 빈혈이 있는 당뇨병 환자에서 EPO의 농도는 실제 혈색소 농도의 감소비율과 차이가 있을 것이라 추측된다. Friedman 등은 당뇨병성 합병증 원인 인자로 가저산소증(pseudohypoxia) 또는 저산소증(hypoxia)을 제기하였고 이런 인자들이 EPO의 상대적 또는 절대적 결핍에 의한 것임을 보고하였다. 방법 : EPO-Trac^(TM 125)I RIA kit을 이용하여 방사면역측정법으로 EPO 수준을 검사하였다. 전혈 3㎖을 5-10㎖ 시험관에 정맥 채혈하였으며, 용혈과 장기간의 보존을 위하여 원심분리를 즉시 시행하여 혈청을 영하 200C에서 냉동 보관 후 일괄적으로 검사 결과를 얻었다. 결과 : 1996년 9월부터 1997년 2월까지 조선대학교 부속병원 내과에 입원한 2형 당뇨병 환자 63례를 대상으로 하여 다음과 같은 결과를 얻었다. 1) 당뇨병성 합병증이 없는 군과 있는 군간의 혈색소, 혈중 EPO농도의 차이는 유의한 차이가 있었으며 혈색소의 감소율보다 혈중 EPO의 감소율이 더 높았다. 2) 당뇨병성 망막증의 유무에 따른 혈색소 농도의 차이는 유의한 차이가 없었으나 혈중 EPO농도는 유의한 차이가 있었다. 증식성군에서만 혈중 EPO의 감소비율이 혈색소에 비해 높았다. 3) 당뇨병성 신증의 유무에 따른 혈색소, 혈중 EPO농도는 유의한 차이가 있었고 혈색소 감소율에 비해 EPO농도의 감소율이 높았다. 신증의 중증도에 따른 혈색소, EPO의 차이는 미세알부민뇨군을 제외하고는 유의한 차이를 보였고 혈색소 감소율에 비해 EPO의 감소율이 더높았다. 4) 당뇨병성 신경병증의 유무에 따른 혈색소 농도의 차이는 유의한 차이가 없었으며 EPO농도는 유의한 차이를 보였다. 혈색소와 EPO의 감소비율은 비슷하였다. 신경병증의 중등도에 따른 혈색소와 EPO농도의 변화는 유의한 차이가 없었으나 stage 3에서는 혈색소감소율보다 EPO감소율이 더높았다. 결론 : 당뇨병성 합병증을 가진 환자에서 빈혈의 정도는 대부분 혈청 EPO치의 절대적 감소에 의함을 간접적으로 밝혀낼 수 있었으며 차후 더 많은 대상으로 비교 분석이 필요하리라 사료된다. Background: Hyperglycemic-induced redox(pseudohypoxia) imbalance is a characteristic feature of poorly controlled diabetes that mimics the effects of true hypoxia on vascular and neural functions and plays an important role on the pathogenesis of diabetic complications. As is true for apparently "normal" insulin levels typically found in NIDDM even in the presence of hyperglycemia, a "normal" erythropoietin level in an anemic diabetic subject may be disproportionally low for the actual red cell mass. Therefore, Friedman et al suggested that pseudohypoxia or hypoxia as an etiological factor of diabetic complications are due to absolute or relative erythropoietin deficiency Method: EPO-TracTM 125I RIA kit was used for the quantitative determination of erythropoietin(EPO) in serum by radioimmunoassay. An adequate sample of blood (3ml whole blood) was collected aseptically by venipuncture in a 5~10ml glass tube to yield a minimum of 400 L of serum per assay. The serum was promptly removed from the clot by centrifugation in order to avoid hemolysis. Then to increase its storage time it was frozen at -200C in a nonself defrosting freezer. Finally, tests were undertaken simultaneously Results We studied 63 cases with diabetes mellitus, who were admitted to Chosun University Hospital from September, 1996 to February, 1997 at the Department of Internal Medicine. We defined the control group, as diabetic patients who did not have anemia(<13mg/dl), diabetic complications(retinopathy, nephropathy, neuropathy) and the remainders were defined as the experimental group(we excluded anemic patients, who had secondary causes of anemia and diabetic patients with end stage renal disease)Data were as follow 1) The relationship of Hb and the 24hr urine protein between diabetic patients with and without complications significantly differed(p=0.02, < 0.001 respectively), but the Hb level was poorly related between diabetic patients with and without retinopathy(except in preproliferative, proliferative subgroups) and neuropathy. 2) Subgroups of patients with diabetic complications had higher 24hr urine protein than patients without diabetic complications, except stage I diabetic neuropathy 3) The EPO level was significantly different between diabetic patients with and without complications. 4) The correlation between EPO and Hb was significantly different, especially in diabetic patients with retinopathy and nephropathy according to severity of diabetic complications, compared with patients who did not have diabetic complications such as retinopathy and nephropathy. Conclusion: We know that anemia induced by diabetic complications is due to relative EPO deficiency than absolute EPO deficiency, and further evaluation and studies are needed on many cases in the future

      • 중증 재생불량성 빈혈 환자에서 신우신염에 대한 광범위항생제치료 중에 속발한 Saccharomyces cerevisiae 진균감염 1예

        김철희,이정호,이정찬,강정현,곽상혁,배광봉,김현수,김종숙,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

        Most patients with aplastic anemia who do not respond to immunosuppressive treatment or are not candidates for bone marrow transplantation die of infection or bleeding. The neutropenia in acute leukemia, aplastic anemia, or occurring subsequently to chemotherapy and bone marrow transplantation increases susceptibility to infection. In general, the number of infectious episodes correlate with the degree and duration of neutropenia. Global immunosuppression produced by conditioning for bone marrow transplantation or graft-versus-host disease, is associated with unusual bacterial and fungal pathogens, or serious viral and protozoan infections. In addition, repeated treatment with broad-spectrum antibiotics is associated with the emergence of resistant organisms and fungal diseases because of the altered microbial microenvironment of the host. The incidence of invasive fungal infection caused by Saccharomycetes eerevisiae in immunosuppressed patients is very rare, compared with that of infection by candida or aspcrgillus species. Cases of Saccharomycetes cerevisiae fungemia occurring in the course of treatment with broad-spectrum antibiotics are reported in patients with extensive burn or with prosthetic valve endocarditis. We experienced a case of urinary tract infection by Saccharomycetes cerevisiae in a 27-year old female patient with severe aplastic anemia. We report the case with a review of relevant literatures.

      • 단기간의 저용량 Cytosine arabinoside 치료에 반응하였던 Down 증후군에 병발한 급성골수성백혈병 1례

        김현수,이정호,이정찬,강정현,곽상혁,김철희,배광봉,김종숙,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

        The incidence of hematologic disorders in patients with Down's syndrome is significantly increased, about 14∼30 - fold higher than in general population and includes neonatal transient abnormal myelopoieis and acute leukemias. The age of onset of leukemia in Down's syndrome is peaking first in the newborn period and then under 4 years of age. Down's syndrome with acute leukemia above the age of 20 is very rare and it's treatment oucome is unclear. The treatment of Down's syndrome with leukemia has been controversial because of toxicity and associated congenital cardiac and other abnormalities. But if treated adequately, children with Down's syndrome show a favorable response to anti-leukemia therapy. A 24-year-old man with Down's syndrome was first seen for the evaluation of anemia and thrombocytopenia. The peripheral blood morphology and bone marrow study revealed acute myelogenous leukemia, cytogenetic study of bone marrow showed trisomy 21. Beacuse of his sicioeconomic condition and medical abnormalities including deafness, visual loss, he was treated with low dose subcutaneous cytosine arabinoside(Ara-C) for 11 days. Complete remission was obtained after 37 days. The complete remission lasted for 5 months. He subsequently relapsed, and died 6 months later.

      • Azathioprine에 반응을 보인 류마티양 관절염에 의한 경막염(Pachymeningitis)1예

        배광봉,이정호,이정찬,곽상혁,강정현,김철희,김현수,김종숙,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

        Rheumatoid arthritis frequently involves the cervical spine and may lead to neurologic impairement. However, direct involvement of CNS structures by inflammatory cells has been reported infrequently. The prevalence of this complication of rheumatoid arthritis is unknown. Inflammatory CNS involvement in rheumatoid arthritis reportedly occurs in the setting of longstanding, active, erosive articular disease and is accompanied by extracranial and extraspinal nodules and vasculitis. This is diagnosed by radiologic finding of CNS nodules or meningeal thickening and by biopsy or autopsy. Treatment with corticosteroid, cytotoxic agent or surgical decompression is helpful. But the majority of patients die within several months of onset of neurologic symptom. Recently, we experienced a case of pachymeningitis caused by rheumatoid arthritis, which resolved repeatedly with azathioprine treatment.

      • 통풍성 관절염의 임상적 고찰

        윤채중,정승문,김영학,김동규,허광식,김태원,배학연,정종훈,이승일,김평남 朝鮮大學校 附設 醫學硏究所 1997 The Medical Journal of Chosun University Vol.22 No.2

        통풍은 Purine 대사의 이상으로 발생하는 질환으로, 고뇨산혈증인 사람의 전부가 통풍으로 발현되지 않고 증상의 출현 양상이 다양하여 진단과 치료에 주의가 필요하며, 조기에 적절한 조치를 한다면 충분히 조절이 가능한 질환이다. 본대학 내과학교실에서는 통풍으로 치료한 32명의 환자에서 임상양상, 병력과 검사소견을 분석하여 다음과 같음 결과를 얻었다. 1. 32명 모두 남자이며, 최초 발병 시기는 24세에서 72세로 평균 43.8±11.9세이었으며, 30대에서 40대까지가 19명(59.4%)으로 대부분을 차지하였다. 내원 당시 나이는 27세에서 75세까지로 평균 52.3±10.4세였으며, 내원시 까지 평균 유병기간은 8.5±6.8년으로 나타났다. 2. 동반 질환으로는 고지혈증 12례, 신장질환 10례, 고혈압 12례, 비만 8례, 당뇨 2례 등이었다. 3. 이환된 관절은 단관절 침범이 19례(59.4%), 다관절 침범이 13례 이었으며, 최초 이한된 관절은 족무지 중족골지골 관절로 19례(59.4%)로 가장 많았고, 통풍 결절은 20례(62.5%)에서 관찰되었으며, 유병기간이 10년 이상된 12례중 11례 (91.7%)에서 결절이 관찰되었다. 4. 평균 혈중 요산치는 9.17±1.75 ㎎/dl이었으며, 8.0 ㎎/dl에서 9.9 ㎎/dl 사이가 19명으로 전체의 59.4%를 차지하였다. Objective: The gout is a heterogeneous group of diseases resulting from tissue deposition of monosodium urate or uric acid crystals from extracellular fluids supersaturated with respect to this end product of human purine metabolism. The clinical manifestations are such as hyperuricemia, gouty arthritis, gouty nephropathy, uric acid nephrolithiasis. We analyze of clinical manifestations and associated factors in gout. Method: We have reviewed the medical records, radiologic findings and clinical results of thirty-two patients admitted at our department from April 1996 to July 1997. Result: 1) All patients were male. The mean age at initial attack was 43.8 years old, ranging from 24 to 72 years old. 2) The mean level of serum uric acid was 9.17mg/dl on admission. 3) The first metatarsopharyngeal joint was involved in 19 cases (59.4%). Tophus was observed in 20 cases (62.5%). 4) Hyperuricemia was associated with hypertension, obesity, nephrolithiasis and hyperlipidemia.

      • 재순환 버퍼 RLS 알고리즘의 탭 가중치 갱신을 통한 개선된 수렴 특성

        김광준,윤찬호,윤민종,나상동 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

        We extend the sue of the method of least square to develop a recursive algorithm for the design of adaptive transversal filters such that, given the least-square estimate of this vector of the filter at iteration n-1, we may compute the updated estimate of this vector at iteration n upon the arrival of new data. The RLS algorithm may be viewed as a special case of the Kalman filter. Indeed this special relationship between the RLS algorithm and the Kalman filter is considered. We begin the development of the RLS algorithm by reviewing some basic relations that pertain to the method of least squares. Then, by exploiting a relation in matrix algebra known as the matrix inversion lemma, we develop the RLS algorithm. An important feature of the RLS algorithm is that it utilizes information contained in the input data, extending back to the instant of time when the algorithm is initiated. The resulting rate of convergence is therefore typically an order of magnitude faster than the simple LMS algorithm. This improvement in performance, however, is achieved at the expensive of a large increase in computational complexity

      • KCI등재후보

        전압가속에 의한 MLCC 열화데이터의 신뢰성 해석

        김종철,김광섭 대한설비관리학회 2004 대한설비관리학회지 Vol.9 No.4

        Accelerated degradation test (ADT) can be a useful tool for assessing the reliability when few or even no failure are expected in an accelerated life test. In this paper, MLCC (Multilayer Ceramic Capacitors), a sort of passive components which have large capacitance(X7R -55℃~125℃) have been tested, and least-square analyses are used to illustrate our approach in which amount of degradation of a DUT following log-normal distribution. We assumed a simple and useful linear model to describe the amount of degradation over time subjected to different voltage levels applied. Tests for linearity of the performance-time relationship, and provide tests for how well the assumptions hold. Also, by using Eyring Model, MLCC's mean life time is assessed. Also, We tested MLCC by Voltage accelerated On-Off test. and analyzed degradation data with log-normal - General log-linear model suggested by Lu and Meeker's Fatigue-Crack-Growth Model.

      • 수정 LVQ 법을 이용한 배전계통의 전압/무효전력 제어에 관한 연구

        김광원,김종일 울산대학교 1999 공학연구논문집 Vol.30 No.1

        본 논문에서는 코호넨 신경회로망을 이용한 배전시스템의 전압 및 무효전력 실시간 제어 기법을 제안하였다. 본 논문에서의 제어 목적은 모든 모선의 전압을 한계값 이내로 유지하면서 배전시스템의 I²R 손실을 최소화하는 병렬 캐패시터 뱅크와 선로전압조정기의 최적 상태를 결정하는 것이다. 이와 같은 이산적인(discrete) 상태를 취급하기에는 코호넨 신경회로망이 적합하지만, 코호넨 신경회로망의 일반적인 학습법인 LVQ는 분류대상 그룹수가 많은 경우에 기준벡터가 feasible영역에서 벗어나는 현상이 발생한다. 이에 본 논문에서는 수정 LVQ법을 고안하여 코호넨 신경회로망을 학습하였으며, 5개의 on-off 캐패시터와 1개의 선로전압조정기로 구성된 30 모선 배전시스템의 전압/무효전력 제어에 제안한 기법을 적용하여 그 타당성을 검증하였다. This paper proposes a modified Learning Vector Quantization (LVQ) to control shunt capacitor banks and feeder voltage regulators in an electric distribution system. The proposed modified LVQ is utilized to training Kohonen Neural Network (KNN). The objective of the KNN is on-line decision of the optimal state of shunt capacitor banks and feeder voltage regulators which minimize losses of the distribution system while maintaining all the bus voltages within the limits. The KNN is tested on a distribution system with 30 buses, 5 on-off switchable capacitor banks and a nine tap line voltage regulator.

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