• Childhood Kidney Diseases
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• v.4 no.1
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• pp.33-39
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• 2000

Purpose: Our study was designed to investigate the association of MHC Class II (DR, DQ) allele with IgA nephropathy and its significance as a prognostic factor for progression to ESRD Material and Methods: 69 children with IgA nephropathy with normal renal function(serum creatinine $\leq$ 1.5mg/dL) was classified as group A and 70 patients who received renal transplantation due to IgA nephropathy were selected as group B. The HLA-DQB1 and HLA-DRB1 alleles were studied by polymerase chain reaction using sequence specific primers. We have compared the difference in alleles between these two groups and with normal control and also examined any possible effect of the MHC class II genes on the histopathological severity and prognosis of IgAN. Results: Mean age was $8.8{\pm}2.9$ years in group A and $35.0{\pm}15.5$ years in group B. Male to female ratio was 2.8:1 in group A and 2.5:1 in group B. There was a significantly higher frequency of HLA-$DQB1^*03\;and\;DQB1^*05$ in Group B. The frequency of HLA-$DQB1^*0302\;and\;^*05031$ allele had increasing tendency in Group B(P<0.05). HLA-$DRB1^*03\;and\;^*05$ were more common in Group B(P<0.05). HLA-$DRB1^*04$ allele was the most common DR alleles in both group, but there was no statistical significance. There were no significant correlation with MHC class 13 genes on the hjstopathological severity in Group A. Conclusion: In conclusion, $HLA-DQB1^*0302\;and\;HLA-DQB1^*05031 $ allele seemed to be more common in transplanted patients compared to group with normal renal function suggesting that this allele is associated with poor prognosis in IgAN. However larger studies and follow up are required to confirm this due to uncharacterized heterogeneity in etiopathogenesis of IgA nephropathy and possibly one or more than one gene may exert influence in determining susceptibility to the diseases.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.646-650
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• 2003

Many surgical techniques for ischemic mitral regurgitation (IMR) have been used with their excellent results and advantages. Here, we report our simple posterior annuloplasty techniques using vascular graft strip with their early results. Material and Method: Twenty two patients (13 male) underwent the operations for IMR (excluding the papillary muscle rupture) from December 2001 to January 2003. Preoperative risk factors were low ejection fraction (<35％, n=9), hypertension (n=13), diabetes (n=9), and renal failure (Cr>2.5, n=4). The wide dissection beneath the both vena cavae and interatrial groove after bicaval cannulation enabled the easy exposure of mitral valve even in the small left atrium. After eight or nine interrupted sutures in posterior annulus for anchoring the 6 mm width vascular graft strip, symmetric (n=8) or asymmetric (n=14) annuloplasty were done. Combined surgeries were CABG (n=21), Dor procedures (n=3), tricuspid valve annuloplasty (n=1), Maze operation (n=1), and aorto-right subclavian artery bypass (n=1). Result: Except for one surgical mortality, all the patients were doing well and the mean grade of regurgitation was decreased from 2.95 to 0.88, however the ejection fraction had not changed significantly just before discharge. Post-operative valve function evaluated before discharge revealed no residual regurgitation in 8 (including 1 patient with mild stenosis due to over reduction), minimal in 11, mild in 2, and mild to moderate regurgitation in 1. One patient who had ischemic cardiomyopathy and renal failure died of the arrhythmia during the hemodialysis. Conclusion: These observations suggest that the annuloplasty with vascular graft strip could be a safe and cost effective techniques for ischemic mitral regurgitation. However, the long term evaluation for the mitral valve function should be defined for the final conclusion.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.961-969
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• 2003

The purpose of this study was to evaluate the fate of left atrioventricular valve regurgitation(LAVVR) following repair of complete atrioventricular septal defects (AVSDs). Material and Method: Between July 1984 and March 2002, repair of complete AV defects were performed in 77 patients. Mean age at surgery was 30.23$\pm$69.11 months (range 1 to 456). Echocardiograms of all survivors after isolated AVSDs correction were reviewed. LAVVR were evaluated with color doppler echocardiography in 64 survival periodically. On each study, LAVVR severity was graded on a 1 to 4 scale, based upon the size of the regurgitated jet. Result: Mild deterioration of LAVV function was fairly common. LAVVR severity increased by >1 grade in 19 patients (30.2%) during the course of the study. However, the deterioration in LAVVR function occurred primarily between 12 and 24 months postoperatively. After the initial 24 postoperative months, LAVVR worsened on only 8 occasions and in each instance worsened by only 1 grade. Deterioration more than 3+ LAVVR occurred in only 3 patients. And deterioration to 4+ LAVVR was not observed after the initial 24 postoperative months but one. Survival curve analysis predicted a 88.2% of ten-year freedom rate from development of 4+ LAVVR after initial operation of complete AVSDs. Conclusion: Postoperative LAVVR remains fairly stable following AVSDs repair, Serious deterioration is rare after 24 postoperative months, especially after the initial 48 postoperative months. But serial follow-up study with echocariogram was need till 24 postoperative months after repair of complete AVSDs.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.611-618
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• 2006

Background: There have been controversies whether mitral valvular surgery is necessary in the patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting. The purpose of this study is to evaluate the long term clinical results of patients with moderate ischemic mitral regurgitation. Material and Method: Between January 1992 and February 2005, 44 patients with moderate ischemic mitral regurgitation underwent coronary artery bypass grafting. Concomitant mitral valvular procedure was performed in 20 patients (group 1) and isolated coronary artery bypass grafting was performed in 24 patients (group 2). There were no significant difference between groups except cardiopulmonary bypass time (p<0.01). Postoperative follow up duration was $30.1{\pm}29.6$ months and last follow up echocardiographic examination was performed at $21.2{\pm}28.0$ months. Result: There was no difference in operative mortality between groups (group 1 vs group 2, 15.0% vs 8.3%, p=0.493). Grade of mitral regurgitation ${(0.81{\pm}0.91\;vs\;1.50{\pm}0.05,\;p=0.046)}$ and reduction in regurgitation grade ${(1.75{\pm}0.93\;vs\;0.70{\pm}1.26,\;p=0.009)}$ were different between two groups. But there were no significant differences in left ventricular ejection fraction ${(34.1{\pm}11.4%\;vs\;41.6{\pm}12.9%)}$, left ventricular end systolic volume ${(118.2{\pm}63.9\;ml%\;vs\;85.6{\pm}281\;ml)}$, New York Heart Association functional class ${(2.1{\pm}0.2\;vs\;2.4{\pm}1.2)}$ and 5 year survival rate ${(85{\pm}8%\;vs\;82{\pm}8%)}$. There was no risk factor for operative mortality and the only risk factor for late death was preoperative atrial fibrillation (p=0.042). There was no significant correlation between mitral valvular surgery and late death. Conclusion: Concomitant mitral valvular procedure in patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting had no significant positive effect on survival and ventricular function compared with isolated coronary artery bypass grafting. Prospective randomized study may be needed to evaluate the necessity of concomitant mitral procedure and to find more effective method for the improvement of ventricular function.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.604-610
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• 2006

Background: Recent improvements in interventional procedure and medical therapy for congestive heart failure result in an increase of number of patients with ischemic cardiomyopathy considered for coronary artery bypass grafting. We retrospectively review the results of CABG in these patients with decreased LV function to know the early and mid-term follow-up results. Material and Method: Between January 2001 and June 2005, 1,143 patients underwent coronary artery bypass grafting and 144 of these patients had preoperative left ventricular function of equal to or less than 35% ${(LVEF{\leq}\;35%)}$. There were off-pump coronary artery bypass grafting (OPCAB) in 66 cases (45.8%), on-pump beating heart coronary artery bypass grafting in 34 cases (23.6%) and conventional coronary artery bypass grafting in 44 cases (30.6%). The combined operations including mitral annuloplasty were 48 cases in thirty five patients (24.3%). Result: The mean number of dstal anastomosis were $3.5{\pm}1.3$. The median postoperative duration of stay in intensive care unit and hospital was 2 days and 8 days, respectively. There were 6 early death (4.2%) and causes of deaths were ventricular tachycardia in 5 patients, small bowel infarction in one patient. Mean follow-up time was $21{\pm}14$ months $(4{\sim}54\;months)$. The 1-year was $95{\pm}2%$ and 3-year survival rate was $83{\pm}7%$, the 1-year and 3-year cardiac event-free survival were ${88{\pm}3%\;and\;69{\pm}7%}$, respectively. Conclusion: Based on satisfactory early and mid-term results in our study, CABG should be carried out as actively as possible in patients with ischemic cardiomyopathy. Postoperative aggressive management for ventricular arrhythmia would be helpful for better results.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.765-769
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• 2007

Background: The curative treatment of choice for empyema is decortication of the pleura. The risks of this treatment however are increased for the patient with reduced pulmonary function, complicated calcification or septic shock. In the past, open window thoracostomy was a final stage treatment for chronic empyema. Relatively safe treatment of empyema could be achieved in difficult cases with a closure of the open window after open drainage and use of a myocutaneous flap (one stage or staged). Material and Method: A retrospective study of the cause, progression and final outcome of empyema patients who received open window thoracostomy was performed. 21 patients were followed from 1995 to 2004 in the department of Thoracic and Cardiovascular Surgery in the College of Medicine, Pusan National University. Result: The average age of the patients was $57.5{\pm}15.5$ years (range $25{\sim}78$ years), of whom 16 (76.2%) were men and five (23.8%) were women. Pulmonary function test results showed an average FEV1 of $1.58{\pm}0.49 L$. The type of empyema was tuberculous empyema in 13 cases (61.9%), aspergillosis in three cases (14.3%), parapneumonic empyema in three cases (14.3%) and post-resectional empyema in two cases (10%). Bronchopulmonary fistula was seen in 14 cases. Eight cases were complicated by severe calcification of the pleura. For the four cases of bronchopulmonary fistula, the patients' serratus anterior muscle was covered in their first operation. The average number of ribs resected was $4{\pm}1$. Closure of the open window thoracostomy was performed in 12 cases. The average time to closure after open drainage was $10.22{\pm}3.11$ months and the average defect of the empyemal cavity before the final operation was $330{\pm}110 cc$. Among the 12 cases, there were two cases of spontaneous closure. In two cases closure was only achieved by using the reserved skin fold during the first surgery. Of the remaining eight cases, in seven we used the myocutaneous flap (four cases of lattisimus dorsi muscle and three cases of pectoralis major muscle), and in one case we used soft tissue. As regards complications of the closure, tissue necrosis occurred in one case, which led to failed closure, and there was one case of abdominal hernia in the rectus abdominis muscle flap. One patient died within 30 days of the surgery and one patient died of metastatic cancer. Conclusion: A staged operation with a final closure using open window thoracostomy, which consists of open drainage, transposition of the muscle and a myocutaneous flap, can be a safe and effective option for the chronic empyema patient who is difficult to cure with traditional surgical methods.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.81-87
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• 2006

Purpose: Few researches have been peformed on the dose distribution of the moving organ for radiotherapy so far. In order to simulate the organ motion caused by respiratory function, multipurpose phantom and moving device was used and dosimetric measurements for dose distribution of the moving organs were conducted in this study. The purpose of our study was to evaluate how dose distributions are changed due to respiratory motion. Materials and Methods: A multipurpose phantom and a moving device were developed for the measurement of the dose distribution of the moving organ due to respiratory function. Acryl chosen design of the phantom was considered the most obvious choice for phantom material. For construction of the phantom, we used acryl and cork with density of $1.14g/cm^3,\;0.32g/cm^3$ respectively. Acryl and cork slab in the phantom were used to simulate the normal organ and lung respectively. The moving phantom system was composed of moving device, moving control system, and acryl and cork phantom. Gafchromic film and EDR2 film were used to measure dose ditrbutions. The moving device system may be driven by two directional step motors and able to perform 2 dimensional movements (x, z axis), but only 1 dimensional movement(z axis) was used for this study. Results: Larger penumbra was shown in the cork phantom than in the acryl phantom. The dose profile and isodose curve of Gafchromic EBT film were not uniform since the film has small optical density responding to the dose. As the organ motion was increased, the blurrings in penumbra, flatness, and symmetry were increased. Most of measurements of dose distrbutions, Gafchromic EBT film has poor flatness and symmetry than EDR2 film, but both penumbra distributions were more or less comparable. Conclusion: The Gafchromic EBT film is more useful as it does not need development and more radiation dose could be exposed than EDR2 film without losing film characteristics. But as response of the optical density of Gafchromic EBT film to dose is low, beam profiles have more fluctuation at Gafchromic EBT. If the multipurpose phantom and moving device are used for treatment Q.A, and its corrections are made, treatment quality should be improved for the moving organs.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.536-542
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• 1999

Background: The purpose of this study is to improve the quality of the diagnostic procedures in the preoperative evaluation so as to reduce the unnecessary thoracotomy and to ensure resectability in non-small cell lung cancer. Material and Method: Of 616 patients who underwent thoracotomy for primary lung cancer from January 1990 to December 1996, 59 patients(9.6%) turned out to have inoperable lesions after the thoracotomy. We reprospectively reviewed the bronchoscopic findings, methods of tissue diagnosis, CT scans, pulmonary function test and lung perfusion scan, reasons for nonresectability, and adjuvant therapy, and then followed up on the survival rate after exploratory thoracotomy. Result: The cell types were squamous cell carcinoma in 38, adenocarcinoma in 15, large cell carcinoma in 3 and others in 3. Primary loci were RUL in 20, RML in 6, RLL in 8, LUL in 13, LLL in 4 and others in 8. The reasons for non-resectability were various; direct tumor invaison to mediastinal structures(n=41), seeding on pleural cavity(n=8), poor pulmonary function(n=2), invasions to extranodal mediastinal lymph node(n=2), technical non- resectability due to extensive chest wall invasion (n=3), small cell carcinoma (n=1), malignant lymphoma(n=1), and multiple rib metastases(n=1). In the follow-up of 58 patients, 1-year survival rate was 55.2% and 2-year survival rate was 17.2% and the mean survival time was 14 months. When compared according to cell types or postoperative adjuvant therapeutic modalities, no significant difference in the survival rates were found. The squamous cell carcinoma was frequently accompanied by local extension to contiguous structures and was the main cause of non-resectability. In adenocarcinoma, pleural seeding with malignant effusion was frequently encountered, and was the major reason for non-resectability. Conclusion: These data revealed that if appropriate preoperative diagnostic tools had been available, many unnecessary thoracotomies could have been avoided. Both the use of thoracoscopy in selected cases of adenocarcinoma and the more aggressive surgical approach to the locally advanced tumor could reduce the incidence of unnecessary thoracotomies for non-small cell lung cancers.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.547-552
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• 2004

Recently, autologous bone marrow cell transplantation (CTx) for angiogenesis and myogenesis in ischemic myocardium has been extensively investigated to improve heart functions. This study was designed to evaluate the effects of CTx with off-pump coronary artery bypass grafting (OPCAB) in patients who were not feasible for complete revascularization. Material and Method: Four male patients underwent CTx and OPCAB simultaneously. Bone marrow was aspirated from iliac bone. Mean 1.5 ${\times}$ 10$^{9}$ mononuclear cells including mean 6.7 ${\times}$ 10$^{6}$ CD34 + cells and 3.7 ${\times}$ 10$^{6}$ AC133 + cells were obtained and concentrated with 10 cc. These cells were transplanted into non-graftable ischemic myocardium after OPCAB. The heart function of all patients were evaluated using the MIBI scan, echocardiogram and MRI preoperatively. The effects of CTx was evaluated using MIBI scan and echocardiogram at 1 month postoperatively. Result: An average of 2 grafts were bypassed to left anterior descending artery territory. Other territories were transplanted with isolated mononuclear cell. All patients had uncomplicated postoperative course. After 1 month follow up, there were improvement in symptom, ejection fraction (from 49% to 55%) on echocardiogram and myocardial perfusion on MIBI scan in all patients. Conclusion: These preliminary data showed improvement of heart function and myocardial perfusion and also showed the feasibility and safety of combined therapy with OPCAB and CTx in ischemic myocardium. However, the effectiveness of CTx alone cannot be readily assessed. Further randomized, controlled studies are required to evaluate the effectiveness of CTx alone.