실험적 급성 허혈성 신부전에서 Verapamil 이 혈중 Polyamine 동태에 미치는 영향

원동준(Dong Jun Won),권현민(Hyun Min Kwon),김용섭(Yong Seop Kim),구자룡(Ja Ryong Gu),권영주(Young Ju Kwon),조원용(Won Yong Cho),김형규(Hyung Kyu Kim) 대한내과학회 1991 대한내과학회지 Vol.40 No.6

N/A It has been proposd that calcium entry from an external medium increases intracellular free calcium to toxic levels during ischemic acute renal failure, and verapamil (ARF) has been suggested as the agentblocking calicium entry into renal cells and protecting renal function during ischemic injury. Polyamines, anorganic cations that play various roles in normal cellular proliferation and differentiation, accumulate in renal failare. Alsa it has been suggested tht the synthesis and metabolism of polyamine are influence by acute changes of the general condition, such as acute renal failure, and are mediated by a calcium influx into the cells. The study was designed to study the protective effects of systemic verapamil pretreatment on renal function and the influence on polyamine metabolism in experimental ischemic ARF in cats. For these purpose, the experimental animals were divided into 2 groups. While Group I (n=5) was an ischemic ARF model by renal artery clamping for 60 minutes, Group II (n=5) was ischemic ARF with systemic verapamil (5 ml/min/kg) pretreatment. The creatinine clearance and plasma and urinary polyamine were measured in each group before and after the renal artery clamp. The results were as follows: 1) Creatinine clearance before and after the renal artery clamp were 10.64±7.18 ml/min/kg and 2.09±1. 70 ml/min/kg in Group I, 4.47±3.38 ml min/kg and 0.60±0.79ml/min/kg in Group II, respectively, So creatinine clearance decreased more significantly in Group II campared with Group I. 2) Plasma polyamine increased after ischemia in Group I. In group I, plasma levels of putrescine, spermidine, and spermine before ischemia were 4.75±0.40 nmol/ml, 0.69±0.09 nmol/ml, and 0.83±0.63 nmol/ml, were elevated to 7.17±2.91 nmol/ml, 9.83±1.46 nmol/ ml, and 2.64±1.14nmol/ml after ischemia. But in Group II, the plasma level of polyamine was not changed, and especially, spermine decreased significantly from 0.83±0.27 before ischemia to 0.49±0.23 nmol/ml after ischenmine (p=0.033). 3) Urine polyamine excretion decreased after ischemia in Group I and Group II. In Group II, urinary excretion of spermidine and spermine before ischemia, 0.13±0.10 nmol/min and 0.17±0.13nmol/min, decreased after ischemia to 0.01±0.01nmol/min (p=0.019) and 0.032±0.26 nmol/min (p=0.0257). 4) In renal tissue, spermine content vas highest. In Group II, preischemic spermine were 397.20 nmol/g and increased to 646.66nmol/g after ischema, But there were no significant changes in the polyamine contents in Group II. From these data, it was suggested that systemic verapamil pretreatment exerts no protective effect on ischemic ARF. Plasma polyamines are elevated in ischemic ARF, and verapamil may protect these elevations.

요관압 상승시 신혈류량 조절에 prostaglandin이 미치는 효과

민영기,양훈모,김종규,이석호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Higher ureteral pressure than in normal condition causes increase in renal blood flow (RBF) and partial impairment of the autoregulation of RBF. Higher ureteral pressure increased renal prostaglandin production, it is not clear whether or not it is also responsible for partial impairment of the autoregulation of RBF. Therefore, we investigated the role which prostaglandin play in the autoregulation of RBF, studying the interaction between ureteral pressure and RBF autoregulation may reveal the role of prostaglandin in tubuloglomerular feedback. For the purpose of this experiment, six anesthetized mongrel dogs were prepared for the measurements of RBF, mean systemic and renal arterial pressure (RAP) and the manipulation of ureteral pressure to 0 cmH20, 20 cmH20 and 40 cmH20. The autoregulation curves were determined during both control and elevation of the ureteral pressure, before and after the pretreatment with indomethacin, a cyclooxygenase inhibitor. The desired ureteral pressure was achieved by vertically elevating the water-filled reservoir connected to the ureteral catheter to 20 cm and 40 cm above the kidney level. In response to the elevation of the ureteral pressure, RBF increased from 167±11 ml/min to 185±8 ml/min, 204±11 ml/min respectively and the renal arterial pressure and the systemic arterial pressure didn't change significantly. During 0 mmHg of ureteral presure threshold pressure of RBF autoregulation was 59±3 mmHg. On the other hand, during 20 cmH20, 40 cmH20 of ureteral pressure, the autoregulation curves shifted upward and rightward from control, threshold pressure is elevated by 74±3 mmHg. The pretreatment of the dogs with indomethacin failed to affect the lower limit of RBF autoregulation during both control (63±5 mmHg) and the elevated ureteral pressure (77±5 mmHg). Since RBF failed to increase in response to the elevated ureteral pressure, RBF autoregulation curves obtained during the elevated ureteral pressure shifted only rightward from indomethacin control. The results indicate that the increased intrarenal level of prostaglandin by increased ureteral pressure or prostaglandin-induced vasodilation does not appear to bear any relation to the reduction in the autoregulatore capacity during elevated ureteral pressure. It seems that the partial impairment of the autoregulation during acute ureteral obstruction is due to the consumption of tubuloglomerular feedback mechanism at 0 mmHg of ureteral pressure and that prostaglandin is neither mediator nor effector of tubuloglomerular feedback mechanism.

Biliary Self-Expandable Metal Stent Could Be Recommended as a First Treatment Modality for Immediate Refractory Post-Endoscopic Retrograde Cholangiopancreatography Bleeding

Sun Young Moon,Jun Heo,Min Kyu Jung,Chang Min Cho 대한소화기내시경학회 2022 Clinical Endoscopy Vol.55 No.1

Background/Aims: Recent reports suggest that the biliary self-expandable metallic stent (SEMS) is highly effective for maintaininghemostasis when endoscopic hemostasis fails in endoscopic retrograde cholangiopancreatography (ERCP)-related bleeding. Wecompared whether temporary SEMS offers better efficacy than angioembolization for refractory immediate ERCP-related bleeding. Methods: Patients who underwent SEMS placement or underwent angioembolization for bleeding control in refractory immediateERCP-related bleeding were included in the retrospective analysis. We evaluated the hemostasis success rate, severity of bleeding,change in hemoglobin levels, amount of transfusion, and delay to the start of hemostasis. Results: A total of 27 patients with SEMS and 13 patients who underwent angioembolization were enrolled. More transfusionswere needed in the angioembolization group (1.0±1.4 units vs. 2.5±2.0 units; p=0.034). SEMS failure was successfully rescued byangioembolization. The partially covered SEMS (n=23, 85.1%) was generally used, and the median stent-indwelling time was 4 days. The mean delay to the start of angioembolization was 95.2±142.9 (range, 9–491) min. Conclusions: Temporary SEMS had similar results to those of angioembolization (96.3% vs. 92.3%; p=0.588). Immediate SEMSinsertion is considered a bridge treatment modality for immediate refractory ERCP-related bleeding. Angioembolization still has arole as rescue therapy when SEMS does not work effectively.

응력 제한조건하의 신뢰성 기반 형상 최적설계

오영규(Young-kyu Oh),박재용(Jae-kyu Oh),임민규(Min-gyu Im),박재용(Jae-yong Park),한석영(Seog-young Han) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.4

The objective of this study is to integrate reliability analysis into shape optimization problem using the evolutionary structural optimization (ESO) in the application example. Reliability-based shape optimization is formulated as volume minimization problem with probabilistic stress constraint under minimization max. von Mises stress and allow stress. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., reliability index approach (RIA), performance measure approach (PMA), single-loop single￢vector (SLSV) and adaptive-loop (ADL), are used. Reliability-based shape optimization design process is conducted to obtain optimal shape satisfying max. von Mises stress and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

Comparing hemostatic resuscitation management of intraoperative massive bleeding with traumatic massive bleeding: a computer simulation

Lee Young Sun,Kim Kyu Nam,Lee Min Kyu,Sun Jung Eun,Hyun Jin Lim,전종헌 대한마취통증의학회 2020 Anesthesia and pain medicine Vol.15 No.4

Background: Appropriate blood component transfusion might differ between intraoperative massive bleeding and traumatic massive bleeding in the emergency department because trauma patients initially bleed undiluted blood and replacement typically lags behind blood loss. We compared these two blood loss scenarios, intraoperative and traumatic, using a computer simulation. Methods: We modified the multi-compartment dynamic model developed by Hirshberg and implemented it using STELLA 9.0. In this model, blood pressure changes as blood volume fluctuates as bleeding rate and transcapillary refill rate are controlled by blood pressure. Using this simulation, we compared the intraoperative bleeding scenario with the traumatic bleeding scenario. In both scenarios, patients started to bleed at a rate of 50 ml/min. In the intraoperative bleeding scenario, fluid was administered to maintain isovolemic status; however, in the traumatic bleeding scenario, no fluid was supplied for up to 30 min and no blood was supplied for up to 50 min. Each unit of packed red blood cells (PRBC) was given when the hematocrit decreased to 27%, fresh frozen plasma (FFP) was transfused when plasma was diluted to 30%, and platelet concentrate (PC) was transfused when platelet count became 50,000/ml. Results: In both scenarios, the appropriate ratio of PRBC:FFP was 1:0.47 before PC transfusion, and the ratio of PRBC:FFP:platelets was 1:0.35:0.39 after initiation of PC transfusion. Conclusion: The ratio of transfused blood component did not differ between the intraoperative bleeding and traumatic bleeding scenarios.

초기 자궁내막암 환자에서의 복강경유도하 질식 자궁절제술과 복식 자궁절제술에 대한 비교 연구

김민규 ( Min Kyu Kim ),최동석 ( Dong Seok Choi ),김우영 ( Woo Young Kim ),최철훈 ( Chel Hun Choi ),김태중 ( Tae Joong Kim ),이정원 ( Jeong Won Lee ),김병기 ( Byoung Gie Kim ),이제호 ( Je Ho Lee ),배덕수 ( Duk Soo Bae ) 대한산부인과학회 2006 Obstetrics & Gynecology Science Vol.49 No.12

목적: 초기 자궁내막암의 수술적치료 시 복강경유도하 질식 자궁절제술 및 골반림프절절제술군과 복식수술군의 수술결과 및 재발율에 대해 비교하고자하였다. 연구 방법: 2003년 3월부터 2005년 5월까지 초기 자궁내막암 환자를 인구학적 특성이 같은 63명을 선택하여 복강경유도하 질식 자궁절제술 및 골반림프절절제술군 26명, 복식수술군 37명으로 나누어 수술 전후 혈색소 차이, 평균수술시간, 취득한 골반림프절갯수, 평균재원일수, 추가치료율, 재발률을 비교하였다. 결과: 복강경유도하 질식 자궁절제술 및 골반림프절절제술을 시행한 군과 복식수술을 시행한 군과의 비교에서 수술 전후 혈색소 차이, 평균수술시간, 취득한 골반림프절 갯수, 평균재원일수, 재발률에 통계적으로 유의한 차이가 없었다. 결론: 초기 자궁내막암의 수술 시 복강경유도하 질식자궁절제술 및 골반림프절절제술 방법이 복식방법에 비해 수술결과 및 재발률에 통계적으로 유의한 차이가 없으며 그 대체 수술법으로 많은 활용이 기대되었다. Objective: To compare laparoscopic surgery with conventional abdominal surgery in patients with early stage endometrial cancer. Methods: A retrospective review of 63 patients with early stage endometrial cancer managed between March 2003 and May 2005. Two groups were defined whether they had been treated by laparoscopy (case group: n=26) or by laparotomy (control group: n=37). We compared age, body mass index (BMI), hemoglobin change, operation time, number of pelvic lymph nodes, hospital stay, case with adjuvant treatment and recurrence between two groups. Results: There was no statistical difference in characteristics (age, BMI, nulliparity, previous abdominal surgery, FIGO stage, histologic grade). between case and control group. In addition, there was no statistical difference in operation data and outcomes between two groups. Hemoglobin changes were 1.1 g/dL (case group) vs 1.7 g/dL (control group) (p=0.072). Operation time was 131 min vs. 115 min. The numbers of lymph nodes obtained were 8.7 vs 7.7 (right) 9.2 vs. 7.6 (left). Hospital stays were 8.4 vs. 9.2 days. Adjuvant treatment cases were 7 vs. 15. Recurrent case was one in each group. Two patients initially evaluated by laparoscopy were converted to laparotomy due to bleeding and adhesion. Conclusion: Laparoscopic surgery for treatment of early endometrial cancer is a safe and effective alternative to laparotomy . However, long-term survival and risk of recurrence have yet to be determined.

적응 루프법을 이용한 진화적 구조 위상 최적설계

황승민,박재용,임민규,오영규,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). Topology optimization is formulated as volume minimization problem with probabilistic displacement constraint. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., RIA, PMA, SLSV and ADL(adaptive-loop), are used. Reliability-based topology optimization design process is conducted to obtain optimal topology satisfying displacement and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

Compressive Behavior of 7xxx Series Al Composites Reinforced with

Seo Young-Ik,Min Kyung-Ho,Lee Kyu-Hwan,Kim Young-Do 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Mechanical properties of 7xxx series Al metal matrix composite (MMC) powders containing different amounts of ceramic were investigated. The ceramic contents of the starting powders were 5 wt.% or 10 wt.%. The powders were uniaxially cold compacted using a cylindrical die with a compacting pressure of 250 MPa and were sintered at in a dry atmosphere for 60 min. For the heat treatment, sintered parts were solution treated at and aged at . Compression tests were conducted to reveal the effect of particle content on the mechanical properties of the composites. Fractography was examined using a scanning electron microscope.

습식텍스쳐를 이용한 단결정 실리콘 광학적 · 전기적 특성 연구

한규민(Han Kyu-min),유진수(Yoo Jin-su),유권종(Yoo Kwon-jong),이희덕(Lee Hi-deok),최성진(Choi Sung-jin),권준영(Kwon Jun-young),이준신(Yi Jun-sin) 한국태양에너지학회 2010 한국태양에너지학회 학술대회논문집 Vol.2010 No.4

The presence of ultrasonic wave in caustic cleaning process enhances the remove pollutants, and more homogeneous, textured structure. The silicon wafers, cleaning in Deconex OF 145 solution (0.5~2wt %) with DIW under ultrasonic environment for 5 min. The presence of uniform thin layer of SiO2 on c-Si surface enhances etching rate in the caustic etching mixture solution of NaOH (1.5 wt %), DI water and IPA (6 wt %) at 90℃ for 20 min and results in a fine, more homogeneous and small textured structure.

체적제어를 이용한 신뢰성 기반 위상 최적화

박재용,황승민,임민규,오영규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. Deterministic topology optimization (DTO) is obtained without considering of uncertainties related to the uncertainty parameters. However, the RBTO can consider the uncertainty variables because it has the probabilistic constraints. In this paper, the reliability index approach (RIA) is adopted to evaluate the probabilistic constraint. RBTO based on BESO starting from various design domains produces a similar optimal topology each other. Numerical examples are presented to compare the DTO with the RBTO.