전슬관절 동통환자의 등속성 근력 평가에 관한 연구

柳碩柱,李聖喆,朴泰永,柳文集,金明昊,鄭宣根 단국대학교 1995 論文集 Vol.29 No.-

We studied 25 cases of patients with anterior knee joint pain without any other knee problems with a isokinetic evaluation technique using Cybex. The results are 1. The peak torques for the knee extensor muscles were decreased statistically 2. The peak torques for the knee flexor muscles were decreased relatively also but not statistically 3. TAE(Torque Acceleration Energy) values for knee extensor & flexors were all decreased from disuse atrophy 4. The torque curve for extensors showed decreased power around 30 degrees of knee flexion

제1형 당뇨병 환자에서 췌도세포 동종이식의 반복시행

양태영,정인경,서인아,오은영,조건영,오승훈,김성주,정재훈,민용기,이명식,이문규,김광원,도영수,주성욱 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.24 No.4

연구배경:췌도세포 이식은 시술이 간편하고 안전하기 때문에 반복이식이 가능하여 그 동안 여러 센터에서 반복이식의 성공을 보고한 바 있다. 국내에서도 본 병원을 비롯하여 몇몇 센터에서 췌도세포 이식이 활발히 시도되고 있으나 사람에서의 동종이식 및 동종 이식의 반복시행은 보고된 바 없는 실정이다. 저자 등은 국내 최초로 췌도세포 동종이식을 시행하여, 혈청 C­펩타이드가 증가하고 인슐린 요구량이 감소하였으며, 혈당농도와 당화혈색소의 안정을 보였다. 그러나 이식 70일 후 다시 인슐린 요구량이 증가하고 C­펩타이드가 감소하여 췌도세포 이식을 다시 시행한 바 있다. 2차 이식 후 70여일이 지난 현재 다시 혈청 C­펩타이드가 증가하고, 인슐린 요구량이 더 감소되어 췌도세포 이식에서 반복 시행의 유용성을 보고하는 바이다. 방법:환자는 32세 남자로 17년전 당뇨병 진단 후 인슐린 치료 중이었으며, 3년전 부터는 만성신부전증으로 혈액툭석을 하고있었다. 1999년 12월 25일 신장이식을 하였고 3일 후 췌도이식을 하였으며, 두번째 이식은 70일 후 시행하였다. 췌도분리는 변형된 Recordi방법과 비연속성 자당 농도차(discontinuous density gradient)를 이용하였으며 분리한 췌도는 배양 후 환자의 신장기능이 정상화되고 미생물학 검사에서 음성을 확인한 후 경피경간으로 간문맥을 접근하여 16G 폴리 에틸렌 카테터를 이용하여 간실질에 이식하였다. 결과:1차 췌도이식시 순수분리전 췌도수는 210,000개, 순수분리후 획득한 췌도수는 90,000개, 순도 95%, 세포양 1.0mL 이었고, 2차 췌도이식시 순수분리전 췌도수는 420,000개, 순수분리후 획득한 췌도수는 370,000개, 순도 95%, 세포양 1.5mL 이었다. 1,2차 모두 간문맥을 통해 약 20분에 걸쳐 간실질에 주입하였다. 췌도이식전 인슐린요구량은 75∼75U/일, HbA1e 8∼10%, C­펩타이드 0.6ng/mL 였으며, 1차 췌도이식수 7일째 인슐린 요구량은 40U/일, C­펩타이드 1.5ng/mL, FPS 109mg/mL 였고, 40일 추적관찰 후 인슐린 요구량이 36U/일, C­펩타이드 1.8ng/mL, HbA1e 6.5∼7.0%로 안정되었다. 그러나 이식 50일째부터 인슐린 요구량이 50∼56U/일, C­펩타이드 0.6ng/mL, FPS 130∼200mg/dL로 혈당 조절이 불안정하여 다시 췌도이식을 시행하였다. 2차 이식후 50일이 경과한 현재, 인슐린 요구량은 26U/일, C­펩타이드 1.8ng/mL, FPS 90∼120mg/dL로 다시 안정되었다. 결론:췌도이식은 반복이식이 가능하며, 본 환자의 경우 인슐린요구량 감소, 혈당의 안정화 및 C­펩타이드가 상승하여 이식한 췌도의 기능을 확인할 수 있었고, 향후 스테로이드 등 면역억제가 유지 용량으로 감량되면 인슐린 요구량은 더 감소될 것으로 기대된다. Over the past 20 years, significant advances have been made in human islet transplantation. However, cases of prolonged insulin independence after islet allotransplantation have rarely been reported and over time, a slight, gradual decrease in insulin secretion appears to occur, as suggested by the lower C-peptide. Although preliminary clinical success achieved over the past few years has been considerably higher with whole pancreatic transplant than with isolated islet grafts, both approaches remain experimental. Islet grafts might gain, over time, increasing credibility and might eventually provide an easier alternative in terms of grafting procedures and patient management, as compared with the more "traumatizing" whole-pancreas transplantation. Also, using islet, re-transplantation is possible. But it is not known whether re-transplantation of islet could be suitable for those patients who lost grafted islet function. The aim of the present study was to investigate the benefits of re-transplantation of islet in previously simultaneous islets-kidney transplant (SIK) patient who have lost graft function. Methods : The recipient was a 32 year old male. First islet transplantation was underwent at December 25, 1999. However, the grafted islets lost function after 70 days. So we performed re-transplantation of islets. The isolation of islet was conducted sterilely on a laminarflow hood and isolated by a modified Recordimethod. The islet was injected slowly into the liver via a cannular placed in the potalvein for 20 minutes. Results : Transplanted islets were 90,000 IEq at first islet transplantation, 370,000 IEq at second islet transplantation. The insulin requirement was reduced from 75-85 to 35-40 U/day, the basal C-peptide level was 1.5 ng/mL at 7 days posttransplant Unfortunately, the grafted islets lost function after 70 days. After second transplantation, the insulin requirement was reduced to 26 U/day. Conclusions : Despite the continuous need for exogenous insulin therapy, islet transplantation can prevent wide glucose fluctuations, thus resulting in normalization of glycemic control and improvement in HbAlc, and also, show that islets can be successfully and safely re-transplanted intraportally in patients who have lost previously grafted islet function (J Kor Diabetes Asso 457~466, 2000).

An Alternative Zero Voltage Switching Method of Boost Rectifier in Power Factor Correction Rectifier/Regulator System using DC Linked Energy Feedback Circuit

Chung-Wook Roh,Bok-Man Kim,Gun-Woo Moon,Myung-Joong youn 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-

A new single phase power factor correction rectifier/regulator with dc linked energy feedback circuit is proposed, which is capable of achieving the zero voltage switching (ZVS) of a boost rectifier stage without any auxil-laiy switch. The performance of the proposed recti-fier/reguiator is demonstrated through a 200 W, 90 kHz prototype. This proposed rectifier/regulator with dc linked energy feedback circuit is particularly suited for distributed power system applications.<br/>

99mTechnetium-가열처리 적혈구에 의한 비장스캔

정순일,이명철,최창운,박석건,조보연,고창순,정준기 대한핵의학회 1986 핵의학 분자영상 Vol.20 No.1

(99m)^Technetium-Heat damaged erythrocyte were used as spleen scanning agents in 12 patients from July, 1985 to April, 1986. We used this scan to evaluate situs inversus, asplenia, accessory spleen, hypersplenism, splenic infarction, tumor staging and evaluation of therapy, especially when the Tc-99m-tin colloid scans were not definite for diagnosis. The techniques applied to these scans were in vivo/in vitro-labeling method and heating-method to damage the erythrocytes. Liver-to-spleen uptake ratios were increased upto 100:1 and interference from the left lobe of the liver was eliminated. These scans were helpful to evaluate the spleen.

Novel Zero Voltage Switching Power Factor Correction Rectifier/Regulator using DC Linked Energy Feedback Circuit

Chung-Wook Roh,Bok-Man Kim,Gun-Woo Moon,Myung-Joong Youn 대한전기학회 1998 Journal of Electical Engineering and information S Vol.3 No.6

B형 만성 간질환 환자들의 간조직내 HBV precore 돌연변이종에 관한 관찰

정정명,이상욱,김석주,하희근,김민기,박영홍 인제대학교 1998 仁濟醫學 Vol.19 No.1

HBV의 C 유전자 영역에는 두 개의 개시 codon이 있는데 앞쪽 개시 codon에서 HBeAg이 합성되고 뒤쪽 개시 codon으로부터 HBcAg가 합성된다. 그리고 이 두 개의 개시 codon 사이를 precore 유전자 영역이라 명명하는데 이 부위에서 HBeAg의 합성과 분비를 나타낸다. 따라서 이 precore 유전자 영역에 변이종이 발생되면 이 영역이 비활성화되고 결과적으로 HBV의 증식은 지속되나 HBeAg의 생산이나 표현은 되지 않을 가능성이 있다. 그리고 이러한 사실은 실제 anti-HBe가 양성인데도, 혈중에 HBV DNA가 고농도로 존재하며, 비전형적인 간염을 나타낸 환자들에서 precore 영역의 염기서열을 분석한 결과 이 유전자 부위에 변이가 있음이 증명되고 있다. HBV precore 변이증에 대한 연구는 현재 세계적으로 진행되고 있으나 아직도 질병과의 관계는 확실히 알려져 있지 않다. 따라서. 저자들은 우리나라의 HBV precore 변이종의 양상과 질병과의 관계를 파악하기 위하여 본 연구를 시행하였다. 그 결과 우리나라의 경우 HBV precore 변이종의 양상은 첫째, 염기서열 1896의 G가 A로 치환된 변이종이 주종을 나타내고 있으며. 둘째, 이 1896변이종은 precore의 다른 유전자 부위에 변이를 동반하는 경향이 높으며, 셋째, HBV precore 변이종은 모든 B형 만성 간질환에서 발생될 수 있을 것으로 사료되나. 간세포암이나 간경변증과 같은 중한 간질환과의 관계에 대해서는 향후 계속적인 연구가 필요할 것으로 사료된다. Aims : In order to determine the relationship between the HBV precore mutant and the severity of liver disease in Korea, we performed liver biopsies in patients with HBV associat ed chronic liver disease and compared the types of HBV precore mutation and histologic findings in the same limier tissue. Method : HBV DNA in liver tissues was amplified by polymerase chain reaction(PCR). The precore mutants were detected by the direct sequencing for them. Results : 1.Total of 59 cases (43 males, 16 females) were studied and the age ranged from 19 to 72 years with a mean age of 36.3 years. The subjects were composed of 26 cases with chronic active hepatitis, 8 with chronic persistent hepatitis, 3 wish chronic lobular hepatitis, 9 with minimal changes, 5 with cirrhosis and 8 with hepatocellular carcinoma. 2.The HBV precore mutants were found in 27 cases(45.8%) and all mutations were G to A changes at nucleotide 1896, creating a stop codon at codon 28. However, 15 cases among 27 mutants of 1896 also had mutation at different precore regions ; one case at 1937, 3 cases at 1840, 6 cases at 1846, 2 cases at 1856 and 3 cases at 1899. respectively. Also, all HBV precore mutants were combined with wild type HBV sequence. 3.The relationship between HBV precore mutants and HBeAg status revealed that 9 cases from 31 HBeAg positive (29.0%), and 18 from 28 HBeAg negative or anti-HBe positive (64.3%) were mutants. More frequent mutations were observed in HBeAg negative cases. 4.In analysis of the types of mutants and histopathological findings of liver disease, 16 among 26 chronic active hepatitis (46.2%), 1 among 8 chronic persistent hepatitis (12.5%), 1 among 3 chronic lobular hepatitis (33.3%), 5 among 9 minimal changes (55.6%), 2 among 5 liver cirrhosis (40.0%) and 6 among 8 hepatocellular carcinoma (75.0%) showed precore mutations. Conclusion : The patterns of HBV precore mutants in Korea could be summarized as follows. Firstly, mast of the mutations were composed of G to A change at nucleotide 1896. Secondly. most of the mutants at nucleotide 1896 are associated with simultaneous mutations at another precore regions. Thirdly, although precore mutations can happen in any histologic status of chronic liver diseases, its possible relationships with serious conditions, such as cirrhosis and hepatocellular carcinoma, need further investigation.

Simple High-Power-Factor Rectifier/Regulator Based on the Forward Converter

Gun-Woo Moon,Chung-Wook Roh,Young-Seok Jung,Myung-Joong Youn 대한전기학회 1996 Journal of KIEE Vol.9 No.2

Novel Two Stage AC-to-DC Converter with Single Switched Zero Voltage Transition Boost Pre-Regulator using DC-Linked Energy Feedback

Chung-Wook Roh(노정욱),Gun-Woo Moon(문건우),Young-Seok Jung(정영석),Myung-Joong Youn(윤명중) 대한전기학회 1996 대한전기학회 학술대회 논문집 Vol.1996 No.7

Novel Zero Voltage Switching Power Factor Correction Rectifier/Regulator using DC Linked Energy Feedback Circuit

Chung-Wook Roh,Bok-Man Kim,Gun-Woo Moon,Myung-Joong Youn 한국정보과학회 1998 Journal of Electrical Engineering and Information Vol.3 No.6

A new single phase power factor correction rectifier/regulator with de linked energy feedback circuit is proposed, which is capable of achieving the zero voltage switching (ZVS) of a boost rectifier stage without any auxiliary switch. The proposed rectifier/regulator gives the good power factor correction (PFC), low current harmonic distortion, and tight output voltage regulation. Moreover, with the proposed scheme, a low cost, high efficiency, and high power density single phase rectifier/regulator can be designed, which is superior to that of a conventional PFC ZVS boost rectifier followed by a ZVS half-bridge dc-dc converter. The operation of the proposed rectifier/regulator is thoroughly analyzed. Also the control strategy and implementation are provided in details. The performance of the proposed rectifier/regulator is demonstrated through a 200W, 90 kHz prototype. This proposed rectifier/regulator with de linked energy feedback circuit is particularly suited for distributed power system applications.

High-glutathione mesenchymal stem cells isolated using the FreSHtracer probe enhance cartilage regeneration in a rabbit chondral defect model

Gun Hee Cho,Bae Hyun Cheol,조원영,정의만,Hee Jung Park,Ha Ru Yang,Sun Young Wang,You Jung Kim,Shin Dong-Myung,Hyung-Min Chung,In Gyu Kim,한혁수 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Mesenchymal stem cells (MSCs) are a promising cell source for cartilage regeneration. However, the function of MSC can vary according to cell culture conditions, donor age, and heterogeneity of the MSC population, resulting in unregulated MSC quality control. To overcome these limitations, we previously developed a fluorescent real-time thiol tracer (FreSHtracer) that monitors cellular levels of glutathione (GSH), which are known to be closely associated with stem cell function. In this study, we investigated whether using FreSHtracer could selectively separate high-functioning MSCs based on GSH levels and evaluated the chondrogenic potential of MSCs with high GSH levels to repair cartilage defects in vivo. Methods Flow cytometry was conducted on FreSHtracer-loaded MSCs to select cells according to their GSH levels. To determine the function of FreSHtracer-isolated MSCs, mRNA expression, migration, and CFU assays were conducted. The MSCs underwent chondrogenic differentiation, followed by analysis of chondrogenic-related gene expression. For in vivo assessment, MSCs with different cellular GSH levels or cell culture densities were injected in a rabbit chondral defect model, followed by histological analysis of cartilage-regenerated defect sites. Results FreSHtracer successfully isolated MSCs according to GSH levels. MSCs with high cellular GSH levels showed enhanced MSC function, including stem cell marker mRNA expression, migration, CFU, and oxidant resistance. Regardless of the stem cell tissue source, FreSHtracer selectively isolated MSCs with high GSH levels and high functionality. The in vitro chondrogenic potential was the highest in pellets generated by MSCs with high GSH levels, with increased ECM formation and chondrogenic marker expression. Furthermore, the MSCs’ function was dependent on cell culture conditions, with relatively higher cell culture densities resulting in higher GSH levels. In vivo, improved cartilage repair was achieved by articular injection of MSCs with high levels of cellular GSH and MSCs cultured under high-density conditions, as confirmed by Collagen type 2 IHC, Safranin-O staining and O’Driscoll scores showing that more hyaline cartilage was formed on the defects. Conclusion FreSHtracer selectively isolates highly functional MSCs that have enhanced in vitro chondrogenesis and in vivo hyaline cartilage regeneration, which can ultimately overcome the current limitations of MSC therapy.