• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.197-211
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• 2023

Purpose To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access. Materials and Methods Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model. Results A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites. Conclusion AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.887-893
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• 2003

External stimuli increases intracellular (IC) $Ca^{2+}$, which increases extracellular (EC) $K^{+}$. To verify $K^{+}$ effects on the vascular contraction, we performed an experiment using mouse aortic endothelial cell. Meterial and Method: We examined the mouse aortic contractility changes as we measured the IC $Ca^{2+}$ change and ionic current by using the voltage clamp technique under different conditions such as: increasing EC $K^{+}$, removing endothelial cell, giving L-NAME (N-nitro-L-arginine methyl ester) which suppress nitric oxide formation, Ouabain which control N $a^{+}$ - $K^{+}$ pump and N $i^{2+}$ which repress N $a^{+}$-C $a^{2+}$ exchanger Result: When we increased EC $K^{+}$ from 6 to 12 mM, there was no change in aortic contractility. Aorta contracted with more than 12 mM of EC $K^{+}$. Ace-tylcholine (ACh) induced relaxation was inhibited with EC $K^{+}$ from 6 to 12 mM, but was not found after de-endothelialization or L-NAME treatment. ATP or ACh increased IC $Ca^{2+}$ in cultured endothelium. After maximal increase of IC $Ca^{2+}$, increasing EC $K^{+}$ from 6 to 12 mM made IC $Ca^{2+}$ decrease and re-decreasing EC $K^{+}$ to 6 mM made IC $Ca^{2+}$ increase. Ouabain and N $i^{2+}$ masked the inhibitory effect of endothelium dependent relaxation by increased EC $K^{+}$. Conclusion: These data indicate that increase in EC $K^{+}$ relaxes vascular smooth muscle and reduces $Ca^{2+}$ in the endothelial cells which inhibit endothelium dependent relaxation. This inhibitory mechanism may be due to the activation of N $a^{+}$- $K^{+}$ pump and N $a^{+}$-C $a^{2+}$ exchanger. $a^{+}$-C $a^{2+}$ exchanger.r.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.689-695
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• 2009

Purpose : To examine the effect of bosentan, a dual endothelin receptor (ER) antagonist, on the development of monocrotaline (MCT)-induced pulmonary hypertension in rats by especially focusing on the pulmonary vascular morphology changes. Methods : Sprague-Dawley rats were treated as follows: controls received a subcutaneous saline injection, MCT-treated rats received a subcutaneous MCT injection, and bosentan-treated rats received a MCT injection followed by treatment with bosentan (20 mg/kg/day). To assess the effects of ER blockade on the time course, the animals were exsanguinated, and their hearts and lungs were dissected after 7, 14, or 28 days. Results : The mean body weights of the MCT- and bosentan-treated rats were significantly lower than that of the control rats on days 7, 14, and 28. Bosentan administration significantly inhibited the progression of right ventricular hypertrophy on day 28 (right ventricle/[left ventricle＋septum]: $0.71{\pm}0.10$ in MCT-treated rats vs. $0.49{\pm}0.09$ in bosentan-treated rats; P<0.05). Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan-treated rats on day 28 ($49.96{\pm}10.06%$ in MCT-treated rats vs. $47.09{\pm}10.48%$ in bosentan-treated rats; P<0.05). In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on days 14 and 28. Conclusion : Bosentan administration in intermediate doses exerts inhibitory effects on lung vascular hypertrophy and right ventricular hypertrophy during the development of MCT-induced pulmonary hypertension in rats.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.333-340
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• 1999

Background: Plasminogen activator inhibitor-1(PAI-1) is known as the primary physiological inhibitor of tissue-type plasminogen activator(t-PA) in the plasma, and is present within the atherosclerotic vessels. Increased plasma levels of PAI-1 are one of the major disturbances of the hemostatic system in patients with diabetes and/or hypertension, and may have multiple interrelations with the important risk factors in the development of atherosclerosis. This study was performed to determine whether altered gene expression of PAI-1 occurs within the arterial wall, and thereby potentially contributing to the increase of cardiovascular risks associated with diabetes and/or hypertension. Material and Method: The aortic vascular smooth muscle cells of the rat were exposed to 22 mM glucose, angiotensin II, and insulin increased PAI-1 mRNA expression with the use of Northern blotting were examined. Also examined were the effects of 22 mM glucose, angiotensin II and insulin on the growth of the rat's aortic smooth muscle cells by using MTT assay. Result: Twenty-two mM glucose treatment increased the PAI-1 mRNA expression in a time- and dose-dependent manner. Aniotensin II treatment synergistically increased the glucose-induced PAI-1 mRNA expression. In contrast, addition of insulin attenuated the increase of 22 mM glucose and angiotensin II induced PAI-1 mRNA expression. Furthermore, treatment of 22 mM glucose, angiotensin II and insulin resulted in a significant increase in cell numbers. This study demonstrated that 22 mM glucose and angiotensin II have a synergistic effect in stimulating the PAI-1 mRNA expression and in the cell growth of the rat's aortic smooth muscle cells. Conclusion: Elevation of glucose and angiotensin II may be important risk factors in impairing fibrinolysis and developing atherosclerosis in diabetic patients.

• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.474-485
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• 2000

Background : Current studies on multimodal strategy for N2 non-small cell lung cancer are being high interest, have drawn much attention. N2 lung cancer, however, is composed of is divided into several sub groups with that have different prognoses. The prognostic factors still remain controversial. Methods : Between January 1990 and June 1999, 180 patients with N2 lung cancer who underwent surgical resection were investigated, excluding 10 of these for surgical mortality. All patients underwent mediastinal lymph node dissection. 20 clinicopathologic factors were investigated by univariable and multivariable analyses to identify significant prognostic factors among resected N2 disease. Results : The overall 5-year survival rate was 20.6%. Multivariable analyses among overall patients revealed 3 significant prognostic factors : Age, Histologic type, Vascular invasion. Based on the result, 49 patients with both age more than 60 and pathologic Non-squamous cell showed a 5-year survival of 5.0%, whereas 37 patients with neither of the factors showed a 5-year survival of 56.6%(p<0.001). And 12 patients with both vascular invasion and pathologic Non-squamous cell showed a 5-year survival of 11.9%, whereas 67 patients with neither of the factors showed a 5-year survival of 33.6%(p=0.01). Conclusion : The prognosis of surgically resected N2 disease varies according to the 3 significant prognosis factors. Tumor size may be an additional influencing factor in the prognosis of N2 disease.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.316-321
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• 2006

Purpose: Differential diagnosis between arteriovenous (AVMs) aud non-arteriovenous malformations (nAVMs) is important in patients with congenital vascular malformations, because AVMs can cause hemodynamic alteration and require immediate treatment. We investigated whether transarterial lung perfusion scintigraphy (TLPS) was useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities. Materials and Methods: Fifty-seven patients (M:F=26:31, $21{\pm}13$ yr, 9 upper and 48 lower extremities) suspected of congenital vascular malformations in extremities underwent TLPS using $^{99m}Tc-MAA$ before embolization/sclerotherapy. Dose-corrected shunt fraction (SF) was calculated from time-activity curve of the lung. Final diagnosis of AVMs was determined by angiography. in patients with AVMs, follow-up TLPS was done for post-therapeutic evaluation. Results: Sixteen patients (8 upper and 8 lower extremities) had AVMs, while the remaining 41 had nAVMs (1 upper and 40 lower extremities). The mean SF of AVMs on TLPS was significantly higher than that of nAVMs ($66.4{\pm}25.8%\;vs.\;2.8{\pm}4.3%$), p=0.003). The sensitivity, specificity, and accuracy of TLPS (cut-off of SF = 20.0%) in diagnosis of AVMs before treatment were 93.8% (15/16), 100% (41/41) and 98.2% (56/57), respectively. The follow-up TLPS and angiography for post-therapeutic evaluation showed concordant results in 13 of 16 patients (81.3%) with AVMs. The mean SF of TLPS was significantly decreased after embolization/sclerotherapy ($69.5{\pm}24.0%\;vs.\;41.0{\pm}34.7%$, p=0.01). Conclusion: TLPS provides hemodynamic information of AVMs in extremities semiquantitatively. Furthermore, the results of TLPS showed a high concordance rate with angiographic findings. Therefore, TLPS is useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.168-175
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• 2003

Fracture about proximal humerus may be classified as the articular segment or the anatomical neck, the greater tuberosity, the lesser tuberosity, and the shaft or surgical neck. Now, usually used, Neer's classification is based on the number of segments displaced, over 1cm of displaced or more than 45 degrees of angulation , rather than the number of fracture line . Absolute indication of a operative treatment a open fracture, the fracture with vascular injury or nerve injury , and unreductable fracture-dislocation . Inversely, the case that are severe osteoporosis, and eldly patient who can't be operated by strong internal fixation is better than arthroplasty used by primary prosthetic replacement and early rehabilitation program than open reduction and internal fixation. The operator make a decision for the patient who should be taken the open reduction and internal fixation, because it's different that anatomical morphology, bone density, condition of patient. The operator decide operation procedure. For example, percutaneous pinning, open reduction, plate & screws, wire tension bands combined with some intramedullary device are operation procedure that operator can decide . The poor health condition for other health problem, fracture with unstable vital sign and severe osteoporosis , are the relative contraindication. The stable fracture without dislocation is not the operative indication . The radiologic film of the prokimal humerus before the operation can not predict for fracture evaluation. It's necessary to good radiologic film for evaluation of fracture form. The trauma serise is better than the other radiologic film for evaluation. The accessary radiologic exam is able to help for evaluation of bone fragment and anatomy. The CT can be helpful in evaluating these injury, especially if the extract fracture type cannot be determined from plain roenterogram of the proximal humerus, bone of humerus head. If the dislocation is severe anatomically , we could consider to do three dimentional remodelling. The MRI doing for observing of bony morphology before the operation is not better than CT If we were suspicious of vascular injury, we could consider the angiography.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.383-389
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• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.177-184
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• 1996

Between 1987 and 1994, 21 patients were treated surgically for aortic aneurysm involving the thoracoabdominal aorta. There were 11 males and 10 females, and their age ranged from 20 to 67 years old and mean age was 41.5 years. Many complained of back pain, chest pain or discomfort, and flank pain, but three patients were asymptomatic. 15 patients had chronic dissection (71.4%) and 6 had nondissecting fusiform or saccular aneurysm(28.5%), and of those 15 patients with chronic dissection, 6(28.5%) had atherosclerosis assniated with hypertension, 5 (23.8%) were Martian syndrome, and 2 (9.5%) were associated with pregnancy. The diameter of an aneurysm ranged from 6cm to 12cm, and their extent was classified as type I in 7(33.3%), type II in 8(38.1%), type III in 3(14.3%), and type IV in 3(14.3%) patients based on Crawford classification for TAA . Diseased aorta was replaced with artificial vascular graft in all but one patient. In whom the aortic tear site due to pseudoaneurysm was closed by primary suture. For the spinal cord protection during the operation, we used partial cardiopulmonary bypass (FV-FA or PA-FA bypass) in 12 patients (57.1%), Biopump (LA-FA bypass) in 4(19.0%), total circulartory arrest and CPB in 2 (9.5%), Gott's heparinized shunt in 1(4.7%), and simple aortic cross clamping in 2 (9.5%). The most common complication after the operation was hoarseness due to unilateral vocal cord palsy which onured in 5 patients (23.8%), and the next common complication was wound infection in 4 patients(19.0%), paraplegia in 2 patients (9.5%), chylothorax in 1 patient(4.7%). The hospital mortality rate was 9.5% (2deaths), and there was no late death. Our experience shows that the graft replacement of TAAA had reasonable rate of mortality, low rate of serious complication, and provided good post operative state of the pati nts, and since the thoracoabdominal aortic operation is not a high risky procedure anymore, we recommend a radical operation for the indicated patients.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.2
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• pp.80-88
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• 1997

Malignant tumors of extremeties involving major neurovascular structures have been treated by amputation. However recent development of diagnostic tools(CT, MRI etc.), surgical techniques, anticancer chemotherapeutic agents, and radiation techniques allow surgeons to treat malignant tumors in the limb without amputation. It has been reported that a local application of low-heat to the tissue with tumor can kill tumor cells. It is, however, not known if the attendant neural and vascular injuries may be recovered. The present study was, therefore, undertakn to address this question in rabbit sciatic nerves. A low-heat injury to the sciatic nerve was induced by perfusing the nerve with $60^{\circ}C$ saline for 30 minutes and the courses of functional and morphological recovery of the nerve were evaluated for 16 weeks. The results are summerized as follows : 1. In the electromyographic nerve conduction test the average amplitude was markedly attenuated at 4 and 8 weeks after the low-heat treatment, but it progressively increased to the level 89.5% of the control at 16 week post-treatment. The average latency in the control group was 0.62 msec. The latency in the experimental group was much longer than this at 4 and 8 week post-treatment, but it progressively reverted to the control level, showing 0.622 msec at 16 weeks. 2. In the needle EMG, many fibrillation potentials and positive sharp waves were appeared until 8 weeks post-treatment. After 16 weeks, however, no fibrillation potential was observed. 3. In the early phase of post-treatment period, the myelinated nerve fibers contained many vacuoles and the number of myelinated nerve fibers appeared to be considerably reduced. However, as time goes myelinated nerve fibers were regenerated, such that after 16 weeks the histologic appearance of the nerve was similar to that of the control group.