다관절 로봇의 구조개선에 관한 연구

차대룡(Dae-Ryong Cha),성진현(jin-Hyuen Seong) 산업기술교육훈련학회 2009 산업기술연구논문지 (JITR) Vol.14 No.3

Today, the goal-oriented machine tool industry, precision, high-speed, complex function, and are collaborating with a robot. A machine tool itself automatically to replace the cutting tool 5-axis machining center at a time, and ends this operation. Therefore, to improve the structure of the Muti-articulated robot can enhance the strength, productivity is expected to have a big effect. Structural Analysis and Dynamic characteristic was able to improve our weak joints. Awards and to improve the bottom two places about 22% Dynamic characteristic be improved. Therefore, the optimal design of the robot working space and high-rigidity and if you can take advantage of the flexibility in the development of a good industrial robot.

혈액투석 개수 후 단핵구배양 상청액에 의한 사람 근위 세뇨관 상피세포의 Fas 유전자 발현에 대한 연구

차대룡(Dae Ryong Cha),조원용(Won Yong Cho),윤종우(Jong Woo Yoon),조상경(Sang Kyung Jo),김형규(Hyung Kyu Kim),장경현(Kyung Hyun Chang) 대한신장학회 2000 Kidney Research and Clinical Practice Vol.19 No.3

N/A Residual renal function rapidly declines after the initiation of hemodialysis and its mechanisms are supposed to be associated with frequent hypotensive episodes during hemodialysis and subsequent ischemic injury to remnant nephron, but blood-membrane interaction might play an important role because of its ability to activate complement system and other various humoral and cellular mechanisms. Blood monocytes are activated by complements, bacterial conta- minants and activated monocytes are known to secrete multiple proinflammatory cytokines such as TNF-α, IL-1β. The expression of TNF-αand IL-1β in mRNA and protein level were examined by RT-PCR and ELISA respectively in patients with ESRD after the initiation of hemodialysis. Author also investigated the mRNA expression of Fas in human proximal tubular cell culture in the presence of TNF-a and PBMC culture supernatant before and after the ini-tiation of hemodialysis. Compared to PBMC separated before the initiation of HD, the amount of cytokine mRNA from PBMC separated after the initiation of HD showed increased tendency from 0.97±0.2 to 1.12±0.28 for TNF-α(p=0.29), from 1.03±0.18 to 1.10±027 for IL-1β (p=0.54). TNF-αand IL-lβ protein level in PBMC culture supernatant also showed increased tendency from 2.25±0.5 to 4.254±3.77 for TNF- α(p=0.10), from 3.5±2.08 to 4.0±4.3 for IL-1β(p=0,25). TNF-a in-creased Fas mRNA expression dose-dependently com-pared to control but it was not stat.istically significant(p=0,37, 0.22). Compared to the the level of Fas expression in HPTC cultured in the presence of pre HD PBMC supernatant, the level of Fas expression increased significantly in the presence of post HD PBMC supernatant(0.64±057 vs 1.05±0.12, p=0.01). As a conclusion, cytokine gene expression and secretion can increase as a result of blood-membrane interaction and these might have some influence on the loss of residual renal function in CRF patients maintained on hemodialysis.

혈액투석시 Double Lumen Silicone Rubber Catheter ( = Permcath ) 사용의 임상적 경험

차대룡(Dae Ryong Cha),김선숙(Sun Sook Kim),이영호(Young Ho Lee),권영주(Young Joo Kwon),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim),선경(Kung Sun),김정숙(Jung Sook Kim),함인귀(In Gui Ham),김미경(Mi Kyung Kim) 대한내과학회 1994 대한내과학회지 Vol.46 No.4

N/A Background: Repeated, long-term access of the vascular system is a prerequisite for successful extended care of the patients with end stage renal disease (=ESRD) treated with hemodialysis. Despite recent technical advances in percutaneous venous cannulation, vascular access remains a major problem in patients requiring acute Hemodialysis. Although the subclavian cannula has gained a large clinical acceptance in recent years, it carries specific risks such as hemothorax, pneumothorax, venus stenosis, thrombus formation and infection. Recently, a double-lumen, central venous catheter made of Silicone Rubber (=Perm cath) has developed for use as a vascular access device, This device is particularly useful in patients who have exhausted other vascular access sites or who have severe cardiovascular disease. Methods: A total of 23 dual-lumen silicone rubber catheters were placed through the internal jugular vein in 23 patients as a vascular access at our institution during the period of April, 1992 through November, 1992. The perm-cath (Hemocath, Quinton, Seattle) is 36 Cm long and each lumen has an internal diameter of 2 mm. Implantation of the catheters occurred in the operating room and under strict aseptic conditions through the right internal jugular vein. A 10 cm subcutaneous tunnel was then created, which extended from the in-cison to a point 2 cm above the ipsilateral clavicle. The catheter was passed out through the upper portion of the subcutaneous tunnel with the Dacron cuff placed 2 cm from the lower end of the tunnel, acting as both an anchor and a barrier to infection. The tip of the catheter was inserted through an internal jngular vein terminating in the right atrium under EKG monitoring. Each lumen of the catheter was filled with 1000 units of heparin sodium (1.5 ml in venous line, 1.5 ml in arterial line) and capped. Results : The mean duration of catheter use was 24±16 days (8 to 119 days), and the complication of perm-cath occurred in 3 cases such as venous thrombosis in 1 case, catheter exit site infection in 1 case, and exit site hematoma in 1 case. During hemodialysis, blood flow rate ranged from 190 to 313ml/min (mean:235±26ml/ min), and venous retrun pressure ranged from 20 to 150 mmHg(mean:65±16mmHg). Total 14 catheters were removed during treatment and the causes of catheter removal were patient death in 8 cases, venous thrombosis 1, recovery from acute rena1 failure 2, fistula maturation 2, infection 1. Conclusion: Internal jugular vein cannulation with silastic catheter which offers a new percutaneous method was provided safe and reliable as the temporary central vein access. The catheters are well tolerated by the patients and have the advantages of immediate use after placement, high blood flow rates, no repetitive venipuncture, and no cardiac dysfunction. Permcath is particulary useful in patients who have exhausted other vascular access site, severe cardiovascular disease, and terrified by repetitive venipuncture. Though our initial experience has been favorable, there will be needed to evaluate the outcome of permcath over longer period of time.

허혈성 신손상후 c - fos 및 Epidermal Growth Factor 유전자 발현양상

차대룡(Dae Ryong Cha),이영호(Young Ho Lee),장미경(Mi Kyung Jang),김난희(Nan Hee Kim),구자룡(Ja Ryong Koo),권영주(Young Joo Kwon),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim),김창수(Chang Soo Kim) 대한내과학회 1994 대한내과학회지 Vol.47 No.6

N/A Objectives: Acute renal failure (ARF) is a syndrome that can he broadly defined as rapid deterioration of renal function resulting in the accumulation of nitrogenous wastes such as urea and creatinine. The incidence of ARF will most likely increase in the future as a predictable by-product of the continuous advances in surgical techniques and pharmacotherapy. The severity of renal dysfunction after ARF depends on the exent of the initial renal damage as well as the pace of repair process, and the regeneration of tubular epithelial cell is essential in the recovery of ARF. Recently several studies reveal the importance of specific growth factor such as epidermal growth factor (EGF), transforming growth factor-alpha (TGFα) and the expression of these genes is increased during the recovery stage of ARF. To evaluate the expression of c-fos and EGF genes involved in cellular proliferation during acute ischemic renal failure, author performed the northern and dot hybridization of renal tissue at different reperfusion time in the ischemic ARF rats. Methods: The experimental animals were divided into three groups. Group I (n=3) was control without any procedure, group II (n=3) was sham operation group (bilateral flank incision and decapsulation were made without renal artery clamping), group III (n=15) was ischemic ARF model by right nephrectomy and left renal artery clamping for 40 minutes. In ischemic group (Group III), rats were divided into three subgroups according to reperfusion time such as 1, 24, 72 hours (IIIa, IIIb, IIIc in each). For these studies, the non-ischemic right kidney removed at the time of initial surgery served as a paired control. Becaus of inter-animal variation in mRNA content for specific genes, five rats were included for each time period. In all cases, whole blood were collected for measurement of serum creatinine at each reperfusion time. Total renal RNA was purified from intact whole kidneys by deproteinization with guanidinium isothiocyanate and phenol/chloroform/isoamyl alcohol. After the isolation of RNA, electrophoresis were done in a 1% agarose gel containing 20 mM MOPS, 1 mM EDTA, 5 mM Na acetate PH 7.0 and 2.2M formaldehyde and confirmed the intact RNA by the 18 S and 28 S ribosomal RNA. RNA was transferred to nylon membrane via vaccum transfer and then hybridization were performed at 65℃ with isotope labelled probes for 24hours, Autoradiographs were obtained and quantitated by computer-assisted dual- wave length flying spot scanner (CS-9000) at 530 nm. Results: In the control group, the serum creatinine was 0.9±0.2 mg/dl; in the sham operation group 0.8±0.3 mg/dl; in the ischemic group after 1 hour reperfusion, the serum creatinine was 0.9±0.3 mg/dl; In the ischemic group after 24hous and 72 hours reperfusion, the serum creatinine was 1.9±0.5 mg/dl and 3.6±1.4 mg/dl respectively. The mean serum creatinine level was statistically significant between control and post-ischemic 24, 72 hours reperfusion group (p<0.05). c-fos gene was rapidly induced by renal ischemia with peak after 60 minutes of reflow and 24 hours later c-fos message was markedly decreased. The expression of c-fos gene was. more markedly increased in the more severe ischemic injury. EGF gene expression was markedly decreased after 1 hour of reflow and substantially increased in activity ?2 hours after ischemia. Conclusion: From the above findings, c-fos gene expression is rapidly induced by ischemia and this gene expression is essential in the recovery phase of acute ischemic renal failure. EGF gene expression substantially increased in activity is probablely associated with renal epithelial cell proliferation. Although the specific roles of c-fos and EGF genes in tissue recovery are not known, the expression of these genes may be play an important role in the recovery phase of acute ischemic renal failure.

신 증후 출혈열에 항 호중구 형질항체 검사의 임상적 의의

차대룡(Dae Ryong Cha),김선숙(Sun Sook Kim),이영호(Young Ho Lee),권영주(Young Ju Kwon),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim),조윤정(Yoon Jeong Cho) 대한내과학회 1992 대한내과학회지 Vol.43 No.4

N/A HFRS seems to be systemic vasculitis such as antineutrophil cytoplasmic autoantibody (ANCA) associated disease. Author purposed to investigate the role of ANCA in the pathogenesis of HFRS and its relation with the clinical findings of HFRS. Methods: Author measured ANCA by indirect immunofluorescent method using alcohol-fixed neutrophils as substrate in 14cases of serologically proven HFRS in the patients serum of oliguric and diuretic phase. Results: 1) The study population consisted of 10oliguric and 4nonoliguric HFRS cases. There were no significant difference in clinical manifestations at admission. 2) ANCA were detected positively in 3 of 10oliguric HFRS cases (2 in oliguric stage, 1 in diuretic stage), and all of nonoliguric HFRS cases were negative. 3) Gross hematuria and proteinuria at the time of admission were showed in all of positive cases, and this abnormal urinary fir. dings spontaneously resolved during the hospital course. There were no significant difference in clinical course and laboratory findings between ANCA positive and negative groups. 4) By indirect immunofluorescence microscopy using alcohol-fixed neutrophils as substrate, all positive cases showed typical cytoplasmic staining pattern (C-ANCA) and none had extrarenal disease. 5) All three ANCA positive cases showed negative in follow up measurement of ANCA 6months later after recovery of disease. Conclusion: From the above findings, pathophysiology of vasculitis in hemorrhagic fever with renal syndrome may be related with ANCA in such eases, but further studies are requested in detail.

칼슘길항제가 급성 허혈성 신손상후 Renin 유전자 발현에 미치는 효과

이규백(Kyu Beck Lee),차대룡(Dae Ryong Cha),김용섭(Yong Seop Kim),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim) 대한내과학회 1997 대한내과학회지 Vol.53 No.3

N/A Objectives: lschemic acute renal failure(ARF) is characterized by an abrupt and sustained decline in GFR within minutes to days after renal ischemia and not immediately reversed on restoration of renal blood flow. The typical delay of a few days to a few weeks suggests reversible parenchymal damage awaiting cell regeneration for functional recovery. Many potentially cell damaging factors, such as ATP depletion, plasma membrane phospholipid degradatian and superoxide-induced membrane damage, play a central part in ischemic injury. More recently, much attention has been focused on the role of calcium, especially ischemic cell injury and the possible therapeutic role of calcium channel blockers emerged from studies conducted several years ago. In the past, it was thought that activation of renin-angiotensin system plays a role in the pathogenesis of ARF. Now the role of angiotensin in human renal ischemia also appears to be controversial. The following study was done in order to investigate the effect of a calcium channel blocker, nifedipine, on gene expression of renin during acute ischemic renal injury. Methods: The Sprague-Dawley rats were divided into 4 groups, group I(n=3) as the control, group II (n=3) as the sham operation group, group III(n=15) as the ischemic renal injury group without nifedipine pretreatment, and group IV(n=15) as the ischemic renal injury model by right nephrectomy and left renal artery clamping for 40 minutes with systemic nifedipine pretreatment(10mg/kg), 1n ischemic renal injury model(group III and IV), rats were further divided into three subgroups according to reperfusion time of 1,24,72 hours. The non-ischemic right kidney removed at the time of initial procedure served as paired control. Total renal RNA was extracted by Chomczynskis method and electrophoresis was done in a 1% agarose gel containing 2,2M formaldehyde. Northern was performed at 42℃ with isotope labeled renin probe for 18 hours, Autoradiographs were obtained and quantitated by a densitometer measured at 530nm. Results: 1) The expression of renin gene was markedly decreased after renal ischemia and slowly recovered to one half of the control level after 72 hours of reperfusion. 2) Renin gene expression pattern of ischemic renal injury with prior nifedipine treatment was similar to the ischemic group without nifedipine pretreatment. Conclusion: These findings suggest that the renin gene expression was markedly decreased after renal ischemia and slowly recovered. Systemic nifedipine pretreatment does not have a significant effect on gene expression pattern of renin in ischemic renal injury.

출혈성 신증후군 환자의 혈장 Atrial Natriuretic Polypeptide 농도 변화

박정의(Jeong Euy Park),차대룡(Dae Ryong Cha),김종웅(Jong Woong Kim),표희정(Heui Jung Pyo),이호왕(Ho Wang Lee),문정식(Jung Sik Moon),황흥곤(Heung Kon Hwang),김대중(Dai Joong Kim) 대한내과학회 1991 대한내과학회지 Vol.41 No.2

N/A Hemorrhagic fever with renal syndrome (HFRS) is characterized clinically by acute renal failure and pathologically by dense hemorrhage in the right atrium and medulla of the kidneys. To investigate whether there is any significant relationship between the changes of plasma atrial natriuretic polypeptide (ANP) and the clinical course, the plasma ANP was measured in 21 patients with HFRS. The plasma ANP was normal to low during the early oliguric phase (94.6±37.0 pg/ml), went up to a very high level (292.4±190.4 pg/ml) at the beginning of diuresis, then fell to a near normal level in a few days. The plasma renin activity (PRA) was very high during the early oliguric phase and fell rapidly in an opposite direction to the plasma ANP as the patients began diuresis. The rapid increase of plasma ANP and decrease of PRA seem to play an important role in the beginning of diuresis in HFRS.

당뇨병성 신부전의 관리와 최신 치료 ; 당뇨병성 신증에 대한 진단 및 검사

강영선 ( Young Sun Kang ),차대룡 ( Dae Ryong Cha ) 대한내과학회 2009 대한내과학회지 Vol.77 No.6

Diabetic kidney disease, as one of the important diabetic complication, developed in 20% to 40% of patients with diabetes and is now the most common cause of end-stage renal disease. Although it has been recommended that annual screening of renal function including microalbuminuria in diabetic patients, many patients are currently under-diagnosed state. Early recognition of diabetic renal complication has a pivotal role in the management of diabetic patients for improvement of patient`s prognosis. The detection of microalbuminuria is particularly important as a marker of early diabetic kidney disease, and is related with an elevated cardiovascular complications. Like other chronic renal disease, diabetic kidney disease has characteristic to show a progressive decline in renal function, but significantly increased cardiovascular mortality even in the early stage of diabetic kidney disease. Therefore, more aggressive trials for detection of the presence of diabetic kidney disease and comorbid cardiovascular disease and management for cardiovascular risk factor reduction and adequate therapeutic intervention for slowing the progression of renal disease is essential to proper management for patients with diabetic kidney disease. (Korean J Med 77:678-685, 2009)

실험적 허혈성 급성신부전에서 Verapamil 이 Prostaglandin E2 에 미치는 효과

김병수(Byoung Soo Kim),차대룡(Dae Ryong Cha),이석준(Suk Joon Lee),김용섭(Yong Seop Kim),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim),심재희(Jae Hee Shim) 대한내과학회 1990 대한내과학회지 Vol.39 No.1

N/A With the development of molecular biology, the derangement of cellular calcium metabolism is known to play an important role in tissue injury. Therefore, the possibility of calcium channel blockers to protect the kidney from ischemia is being researched extensively. But it is suspected that other homeastatic mechanisms including prostaglandin (PG) may be interrupted by calcium channel blockers because the results of each studies were different. And so we attemped to investigate the passible effects of calcium channel blockers such as verapamil on urine PG E2 excretion in ischemic ARF model by clamping both renal arteries of the cat for 60 minutes. Of eight experimental cats used in the study, one group with faur cats was pretreated with systemic verapamil infusion (5μgkg/min) for two hours before clamping, and four other cats were control group. Urine collection was taken for 20 minutes before clamping and 1SO minutes after release of the clamp. Blood sampling was done at 10 minutes before clamping and 90 minutes after release of the clamp, The level of Na, K, creatinine and inulin in serum including urine and of urine PGE2 by RIA were measured. The results were as follows: Ccr in the experimental group was significantly lower than that of the control group in both preischemia and postischemia(p<0.05). The urine PGE2 level was lower in the experimental group compared with the control group in both preischemia and postischemia, significant at preischemia (p<0.05). FeNa was significantly higher in the experimental group than that of the control group in both preischemia and postischemia(p<0.05). The urine amount at postischemia in both group was significantly lower than that at preischemia (p<0.05). These results suggest that the ischemic ARF by renal artery clamp in the cat can not be protected by systemic pretreatment with verapamil, possibly due to the supression of PGE2 secretion and Ccr.

지속성 외래 복막투석중인 당뇨성 신부전에서 Verapamil 의 복강내 투여가 β2 - Microglobulin 에 미치는 영향

변현주(Hyun Ju Byun),차대룡(Dae Ryong Cha),권현민(Hyun Min Kwon),권영주(Young Ju Kwon),조원용(Won Yong Cho),김형규(Hyoung Kyu Kim) 대한내과학회 1991 대한내과학회지 Vol.41 No.5

N/A In diabetic renal failure, generalized vasculopathy including capillaries is presented, and so there may be some difference in ultrafiltration and mass transport from that of non-diabetic renal failure. Recently, several studies show that intraperitoneal administration of Ca++ antagonist may increase ultrafiltration and mass transport of small molecular weight substance in CAPD. It suspected that the effect of intraperitoneal administration of verapamil on CAPD, may have different response in diabetic and non-diabetic renal failure. In order to evaluate the effects of calcium antagonist (verapamil) on the permeability of the peritoneal membrane in patients on CAPD, serum levels and clearances of creatinine, urea, and β2-Microglobulin, mass transferarea coefficient, ultrafiltration rate and glucose absorption were measured. The study group was devided by 5 non-diabetic (age 33.4+12.4 years, treated for 10.1+8.4 months, Group I) and 5 diabetic (age 53.2+13.7 years, treated for 16.6+15.2 months, Group II) renal failure patients and the study was carried out using 1.65% dextrose dialysate solution for 240 minutes dwell time (phase I), and after the intraperitoneal administration of 10 mg of verapamil the peritoneal dialysis was done by same method as phase I (1phase II). To evaluate the effects of verapamil, percent difference of change between phase I and phase II was calculated. All the values here are mean. The results are: 1) Serum levels of creatinine and β2-Microglobulin were lower in Group II (11.4 vs 6.8 mg/dl, 39.4 vs 18.2 mg/dl) (p<0,01). 2) Peritoneal clearance of creatinine was higher in Group II (6.322 vs 7.072 ml/min), but the increasing rate after instillation of verapamil was slightly lesser than Group I (6.5 vs 4.0%) (not significant). 3) Peritoneal clearance of β2-Microglobulin was higher in Group II (0.626 vs 0.88 ml/min), and the increasing rate after instillation of verapamil was marked in both group, especially in Group I (83.5 vs 36.1%) (not significant). 4) MTAC was higher in Group II (9.7 vs 12.78 ml/min), but the increasing rate of it was greater in Group I (15.4 vs 3.58%) (not significant). The peritoneal permeability was greater in Group 1I probably due to increased permeability and changed structures of peritoneal capillaries in diabetic disease, and the effects of calcium antagonist (verapamil) on peritoneal permeability was lesser in Group II. It suggests that the intraperitoneal administration of verapamil increase the efficiency of CAPD in general, but the benefit may be lesser in diabetic patients.