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      • SCOPUSKCI등재

        단계적 온도 하강법을 이용한 췌도세포 냉동보존법

        정인경,오승훈,김병준,양태영,이병완,하창영,노정현,정재훈,민용기,이명식,이문규,김광원 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.26 No.1

        연구배경:최근 당뇨병의 새로운 치료법으로 시도되고 있는 췌도이식은 충분한 췌도수의 확보와 췌도생존율을 높이기 위한 면역억제제 사용이 제한점이 되고 있다. 본 연구의 목적은 이식 전 충분한 췌도 수의 확보를 위해 분리한 췌도를 냉동보존하는 방법을 확립하고 냉동보존한 백서 췌도세포의 시험관내 그리고 생체내 기능을 조사하였다. 방법:분리한 백서의 췌장소도를 48시간 배양한 후 한 시험관당 췌도세포 1000개씩 나누었다. 냉동보존은 6개의 시험관에 DMSO를 첨가한 후 초 냉각(supercooling), 핵화(nucleation)단계를 거친 후 99% isopropanol과 액체질소가 들어있는 dewer를 이용하여-0.25℃/분의 냉각속도로 -40℃까지 단계적으로 얼린후-70℃ 액체질소 탱크에 보관했다. 해동은 냉동시킨 vial들을 액체 질소 태으에서 꺼내 37℃ 항온조에 담가 급격히 해동시킨 후, 원심분리하여 상층액을 제거하고 각 vial에 0.75M sucrose 용액을 가한 후, 10% fetal calf serum이 함유된 RPMI 1640 media에서 배양하였다 각각 6개의 시험관에서 해동한 췌도들을 광학현미경 및 형광현미경하에서 췌도의 모양과 생존율에 대해 조사하고 인슐린 정적반응을 알아보았다. 또한 분리한 췌도를 냉동보존하지 않고 이식한 경우를 대조군(6마리)과 생체내 기능을 비교하였다. 결과:① 냉동보존후 획득한 췌도의 수와 생존율 해동후 획득한 췌도의 수는 해동시킨 당일날이 902±21, 24시간 배양 후에는 857±16, 72시간 후에는 817±18개로 점차 감소되었다. AO/PI 염색상 각 췌도의 생존율은 냉동 전을 100으로 하였을 때 해동당일, 24시간 후, 72시간 후가 각각 60±5, 80±5, 90±5%로 해동후 3일간 배양하였을 때 냉동전의 수준으로 회복하였다. ② 냉동보존후 췌도의 포도당에 대한 정적 인슐린 분비능:냉동직후 감소된 경향을 보였으나 해동후 3일간 배양한 췌도의 인슐린 분비는 냉동전과 통계적으로 의미있는 차이가 없이 냉동보존 전의 수준으로 회복되었다. ③ 냉동보존후 췌도의 포도당에 대한 동적 인슐린 분비능:냉동보존한 췌도를 해동후 3일째의 인슐린 동적 분비능은 냉동 전과 마찬가지로 자극 인슐린의 반응의 제1기와 2기가 잘 관찰되었다. ④ 냉동보존한 췌도세포 이식 후 혈당 변화:스트렙토조토신으로 유도된 당뇨병 쥐에 췌도이식 후 혈당은 냉동보존한 췌도이식군에서 대조군에 비해 혈당의 조절효과가 더 오래 지속되었다. 결론:소동물에서 단계적 온도 하강법을 이용한 췌도세포 냉동보존법을 확립하였으며 이는 기능, 구조 및 생존율에 큰 이상을 보이지 않았으므로 장차 사람의 췌도세포 동종이식시 부족한 췌도세포수를 극복하고 면역반응을 줄일 수 있는 매우 유용한 방법이 될 것으로 판단된다. Background : Although islet transplantation has been attempted to reverse the state of diabetes, achieving a critical number of islets and modulating the immune response limit the success of islet transplantation. Cryo-preservation of islets offers many important benefits for islet transplantation by collecting islets with a wide variety of HLA phenotypes and islet MHC expression. The aims of this study was to determine the optimal conditions for cryo-preservation by using a controlled cooling method and to evaluate in vitro and in vivo functional properties of the cryo-preserved islets. Methods : Collagenase-isolated, Ficoll-purified islets were cultured for 48 hours. They were aliquoted into freezing tubes (1000 islets per tube), equilibrated with 2M dimethyl sulfoxide (DMSO) in three steps, supercooled, nucleated, and controll-cooled at rate of 0.25℃/min to - 40℃ prior to storage at - 196℃. Rapid thawing and removal of DMSO with 0.75 M sucrose preceded 48 hour of culture and the morphology, viability, glucose-induced insulin secretion, and in vivo function of rats transplanted with cryopreserved islets was reexamined. Results : ① Recovery was 90.2±0.2%, 85.7±0.1% and 81.7±0.1% immendiately after, 24 hours and 72 hours after thawing respectively. The viability was 60±5%, 80±5%, 90±5% immediately after, 24 hours and 72 hours after thawing respectively. ② The glucose-stimulated-insulin secretion (GSIS) tended to decrease immediately after thawing, but GSIS increase to the level of pre-cryopreservation 72 hours after thawing. ③ The in dynamic GSIS, the first and the second phase of insulin secretion were well preserved in islets cultured for 72 hours after thawing. ④ The cryopreserved islets were cultured for 3 days and transplanted into renal sub-capsular space of streptozotocin (STZ) induced diabetic rats. The duration of normoglycemia in the STZ-induced diabetic rats transplanted with cryopreserved islets was significantly longer than of the fresh islets. Conclusion : The optimal condition of cryopreservation using the controlled cooling method was established in rat pancreatic islets. This cryopreservation method can be a feasible approach for human islet transplantation (J Kor Diabetes Asso 26:64~74, 2002).

      • KCI등재
      • 도금사업장의 작업환경의 유해인자 노출수준에 관한 연구

        문덕환,도수영,이채관,황용식,선병관,손병철,김대환,이창희,김휘동,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

        Objective : For the purpose of preparing the fundamental data and assessing the status of exposure level of chemical substances and physical agents. Methods and Material : Such as noise, two types of dust, four types of metals, seventeen types of organic solvents, and four types of other materials classified by specific chemical substances in 21 metal product plating factories classified by 28 processes. The author determined exposure level on those hazardous materials from Jan. to Dec. 2001. Results : The results were as follows: 1. The exposure level for noise was exceeded to Threshold Limit Value(TLV) in the process of 6 cases of Machining, 5 and 4 cases of pre and post-buffing, and 6 cases of waterdrop-removing, the mean noise level of all of processes was not exceeded to compliance level. 2. The exposure level for dust was not exceeded to TLV at all. 3. The exposure level for Chromium(Cr) was exceeded to TLV in Chromium plating process, metal exposure level including Zinc(Zn), Manganese(Mn), and Lead(Pb) was not exceeded to TLV. 4. The exposure level of toluene in case of organic solvents was exceeded to TLV in 1 case of finishing/cleaning, coating/developing process, respectively. 5. The exposure level of four types of other materials classified by specific chemical substances were not exceeded to TLV. 6. The exposure level for dust and metal including Zn, Mn, and Pb was decreased in comparison with two results of air monitoring performed. There was no difference of the exposure level for Cr, noise, and four types of other materials classified by specific chemical substances, and the exposure level for organic solvents was slightly increased. 7. The exposure level for noise in factories employing more than 21 workers was higher than that for noise in foadtories employing less than 20 workers. The more workers, the lower exposure level in metal including Zn, Mn. The exposure level for Cr was increasing in factories employing more than 51 workers, and the more workers the lower exposure level in organic solvents. Conclusion : According to above results, this study suggests positive work environment managements in processes exceeding exposure limit value as well as continuously consecutive work environment management in processes not exceeding exposure limit value and revealing no chronological difference of exposure level should be needed.

      • 電解 Boronizing에서 Al-B合金 添加의 影響과 耐高溫酸化性에 對하여

        양훈영,유병돈,김문철 연세대학교 산업기술연구소 1980 논문집 Vol.12 No.1

        To investigate the effect of Al-B alloy addition on the boride thickness, hardness, wear and heat-resistance of the boride layer, an electrolytic boronizing with various amount of Al-B alloy in the electrolyte has been carried out at the current density of 0.5A/ ㎠ and in the temperature range of 800~1,000℃. Also aluminizing was conducted to the boronized specimen in order to find out whether aluminium would penetrate into the boride layer and improve the heat resisting property. From the experimental work, following results were obtained. 1) Increased thickness of boride layer and hardness were resulted with increased addition of Al-B alloy. Excess addition of the alloy, however, inhibited the boronizing because of the increasing viscosity of electrolyte. 2) Thickness of the boride layer increased rapidly with increasing temperature which improves the fluidity of electrolyte and diffusion rate. 3) Wear resistance improved markedly by boronizing and better result obtained by Al-B alloy addition. 4) Aluminium diffused into the boride layer by aluminizing of the boronized specimen, showing excellent heat resistivity even at 1,000℃.In this case,however, decreasing wear resistance was inevitable.

      • KCI등재
      • HBx형질전환 생쥐에서 발생한 간세포암종에서 H-ras 및 c-myc의 발현에 관한 연구

        문형배,소병준,김학철,윤기중,한원철,조향정,유대열,정영진 圓光大學校 醫科學硏究所 2002 圓光醫科學 Vol.17 No.2

        <연구목적> HBx형질전환 생쥐에서 발생한 간세포암종의 발암과정에 종양유전자(H-rgs, c-myc)의 발현 정도를 조사하고자 하였다. <연구방법> 정상생쥐 12마리(4-18개월) 및 HBx 형질전환 생쥐 44마리(4-18개월)를 대상으로 포르말린에 고정하고 파라핀에 포매한 간 조직을 이용하여 면역조직화학적염색을 실시하였다. 실험군은 정상 부위, 이형성 부위 및 종양 부위로 구분하였으며, 종양 부위는 소결절성병변 부위와 간세 포암종 부위로 구분하였고, 이형성병변 부위는 이형성병변만 발견되는 부위, 소결절성병변과 동반된 이형성병변 부위 및 간세포암종과 동반된 이형성병변 부위로 구분하였다. <연구결과> H-rgs의 발현은 정상 간조직에 비하여 이형성병변 부위(P<0.05) 및 종양 부위(P<0.01)에서 증가하였으며, 소결절성병변 부위과 간세포암종 부위 사이에서는 간세포암종 부위에서 증가된 경향이었으나 통계학적으로 유의한 차이가 없었으며, 각 이형성병변 부위 사이에서도 유의한 차이는 없었다. c-myc의 발현은 정상 간조직 및 이형성병변 부위에 비해 종양 부위에서 증가하였으며(P<0.001), 소결절성병변 부위와 간세포암종 부위에서는 비슷하였고, 각 이형성병변부위 사이에서도 비슷하였다. <결론> HBx형질전환 생쥐에서 발생하는 간세포암종의 발생에 H-rgs는 이형성 변화를 일으키는 시기에 관여하며, c-myc은 이형성병변에서 암으로 이행하는 시기에 관여할 것으로 생각한다. Background: This experiment was designed for the expression of H-ras and c-myc in hepatocarcinogenesis of the HBx transgenic mice. Methods: Immunohistochemical stains in the paraffin embedded tissue of the liver were used for the detection of H-ras and c-myc in the 12 normal mice and 44 HBx transgenic mice of the 4-18 month old. Results: Expression of the H-ras was significantly increased in the dysplastic area (P<0.05) and tumor area (P<0.01) than in the normal liver. But there were no differences of H-ras expression between areas of microscopically identified hepatocellular carcinoma (MI-HCC) and grossly identified hepatocellular carcinoma (GI-HCC) and dysplastic areas among the only dysplastic areas, dysplastic areas with MI-HCC and GI-HCC. Expression of the c-myc was significantly increased in the tumor area (P<0.001) than in the normal liver and dysplastic area. But there were no differences of c-myc expression between areas of MI-HCC and GI-HCC, and dysplastic areas among only dysplastic areas, dysplastic areas with MI-HCC and GI-HCC. Conclusions: Our study suggests that H-ras is related to the dysplastic change and c-myc is related to the neoplastic change in the hepatocarcinogenesis of the HBx transgenic mice.

      • 응력-변형 거동 예측을 위한 탄소성 구성모델의 비교

        문창열,박병수,조영묵 三陟大學校 1999 論文集 Vol.32 No.2

        This paper is results of numerical analysis to investigate stress-strain behavior of sandy soils. Tree different constitutive relationships of Modified cam-Clay Model, Hyperbolic Model and Lade's Double-Work-Hardening Model were applied to predict stress-strain behavior of them. For each model, constitutive relations as well as parameters governing stress-strain behavior were programmed numerically. Weathered granite soil, tests were carried out with rich in Korea, and Ju Mun Jin Standard Sand were used as specimen of sandy soil. Stress-strain behaviors of these soils were obtained by performing isotropic compression and drained triaxial compression tests. For Weathered granite soil, tests were carried out with three different water contents determined on the basis of compaction test results. Four different relative densities were used with Ju Mun Jin Standard Sand. Numerically Predicted results with three different models were compared with tested results. Therefore applicability and problems of each model were discussed. Numerical analysis about sensitivity of parameters was also performed to investigate how these parameters influenced stress-strain behavior of sandy soils.

      • KCI등재

        관동맥우회술 후 발생한 급성 장간막경색 1예

        문용화,김지현,강웅철,박병은,고영국,최동훈,유경종 대한내과학회 2004 대한내과학회지 Vol.66 No.3

        관동맥우회술을 포함한 심장수술 후에 생기는 급성 장간막경색은 매우 드물지만 치명적인 합병증으로 발생률은 비교적 낮으나 사망률은 매우 높게 보고 되고 있다. 본 증례에서는 55세 여자 환자가 관동맥우회술을 시행받고 수술 후 1일째에 발생한 복부통증에 대해서 장간막경색증을 의심하지 못하고 수술과 연관된 비특이적 증상으로 판단하였으나 그 후 환자의 증상이 악화되면서 상장간막동맥 혈전 색전증에 의한 광범위한 급성 장괴사로 판명되었다. 관독맥우회술 후 상장간막 동맥에 생긴 혈전색전증에 의해 발생한 급성 장간막경색의 증례는 국내에 보고된 바 없고 본 증례를 통해 교육적인 경험을 하였기에 저자들은 문헌고찰과 함께 보고하는 바이다. 심폐우회술을 요하는 심장수술을 받은 환자 중 특히 급성 장간막허혈의 위험인자를 가지고 있는 환자에 대해서는 급성 장간막허혈이 생길 수 있다는 세심한 관찰이 진단이 늦어지지 않게 하는 방법이며 장간막허혈이 의심되면 즉시 적극적인 진단 및 치료적인 접근을 시도해야 하겠다. Acute mesenteric ischemia leading to massive bowel infarction following cardiac surgery particularly coronary artery bypass graft (CABG), is reported to be a very rare but serious life-threatening complication. In this case, a 55-year-old female underwent CABG and complained of abdominal pain on the first postoperative day, which was thought to be nonspecifically related to the operation wound, In the further hospital course, the patient was found to have extensive acute mesenteric infarction due to thromboembolism of superior mesenteric artery. This is a valuable educational case, since only high index of suspicion does not delay making a diagnosis especially in the patients with risk factors of acute mesenteric ischemia after cardiac surgery requiring cardiopulmonary bypass. On suspicion of acute mesenteric ischemia, an aggressive diagnostic and therapeutic approach should be performed immediately.(Korean J Med 66:317-320, 2004)

      • 猪笭湯이 實驗的 賢贓障碍家兎에 미치는 影響

        文永熙,金美淑,李炳柱,林起龍 조선대학교 약학연구소 1991 藥學硏究誌 Vol.13 No.1

        This study was attempted to investigate the effect of Jueryeong Tang(JRT) on renal failure of the rabbit treated with folate. Serum creatinine, blood urea nitrogen and serum uric acid in folate-treated rabbits were markedly increased and creatinine clearance was decreased by comparing with the normal group. JRT(900㎎/㎏) given orally produced significant reduction in concentration of both serum creatinine and blood urea nitrogen by comparing with the corresponding folate-treated group. while did increased clearly in creatinine clearance. The morphological changes of arcuate arteries and glomeruli evoked by folate treatment were almost returned to normal state after administration of JRT. (900㎎/㎏). These experimental results suggest that JRT may greatly improve renal failure of the rabbit induced by folate treatment.

      • 디지털 위서 통신 채널의 비선형성 보상을 위한 신경회로망 등화기의 설계 및 평가

        윤병문,김정희,임영선,진근식,신요안 崇實大學校 生産技術硏究所 1995 論文集 Vol.25 No.2

        A digital satellite communication channel has a strong nonlinearity with memory due to saturation characteristics of the high power amplifier in the satellite and transmitter/receiver filters used in the overall system, and can be well modelled by a nonlinear Volterra series. In this paper, we design and evaluate neural network based adaptive equalizers for compensation of nonlinearities in digital satellite communication channels. We consider CMLP (complex multi-layered perception). CRBFN (complex radial basis function network) and complex ρth order Volterra filter as equalizers, and evaluate their performances in terms of symbol error rate under various noise conditions. In particular, a complex hybrid learning algorithm of k-means clustering and LMS (least mean squares) algorithm is proposed for the CRBFN. Computer simulation results show good performance for all the equalizers considered

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