• Journal of Chest Surgery
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• v.38 no.9 s.254
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• pp.609-615
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• 2005

Background: Some controversy still exists concerning the operative indications of coronary fistulas. Nevertheless, a short-term and long-term outcomes are excellent with surgical interventions. In this study, we assessed our surgical results on this disease entity during the last 20 years. Anatomic diversity was described as well. Material and Method: From April 1986 to March 2005, 20 patients with coronary fistulas underwent surgical correction in Seoul National University Children's Hospital. Their medical records were reviewed retrospectively. Result: Twelve patients ($60\%$) were asymptomatic prior to surgery. All had electrocardiogram and echocardiogram and all but 3 had coro-nary angiogram preoperatively. Anatomically, none of them had two or more coronary fistulas. The sites of origin were left coronary system in 11 patients and right in 9. The draining sites were right ventricle in 11, right atrium in 3, left ventricle in 3, main pulmonary artery in 2, and superior vena cavae in 1. All of the involved, the coro-nary arteries were dilated or aneurismal. In 1 case, there was atherosclerotic change but no ischemic evidence in preoperative electrocardiogram. Operative techniques included external obliteration (13), internal obliteration (5), and both (2). External obliteration was done by ligation of the fistulous tract only in T patients, by fstula ligation plus plication in 3 and by plication or patch closure via fistulotomy in 3. There was no operative mortality. All of postoperative morbidities including transient sinus arrhythmia (2), complete atrioventricular block (1), decreased left ventricular function (2), ventricular tachycardia (1), pericarditis (1), and seizure (1) improved on discharge. The mean follow-up was 55.1$\pm$50.2 months (4.0 months${\~}$18.0 years) and there were no recurrences of fistula. There was 1 second operation for aortic root aneurysm, which developed after external patch closure of right coronary fistula. Conclusion: We demonstrated here that coronary fistulas can be cured with excellent clinical outcome and low operative risk under precise diagnosis. Understanding the anatomic diversity will help to construct surgical plans.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.2
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• pp.98-104
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• 2012

Objectives : This study aimed to investigate the correlations between neurological and psychiatric symptoms at two weeks after stroke. Methods : For 412 stroke patients, stroke severity was evaluated by the National Institutes of Health Stroke Scale(NIHSS), disability by the Barthel Index(BI) and modified Rankin Scale(mRS), cognitive function by the Korean Mini-Mental State Examination(K-MMSE), and muscle power by grip strength. Psychiatric symptoms were assessed by Symptom check list-90-Revision(SCL-90-R), consisted of nine symptom domains : Somatization, Obsessive-compulsive, Interpersonal sensitivity, Depression, Anxiety, Hostility, Phobic anxiety, Paranoid ideation, Psychoticism, and Additional items. The correlations between the neurological and psychiatric symptoms were investigated at the time of admission and before discharge(i.e. before and after treatment). Results : At the time of admission, NIHSS score was associated with scores on Phobic anxiety and Additional items ; and scores on BI and mRS were associated with Depression, Phobic anxiety and Additional items. At the time of discharge, NIHSS score was associated with scores on Somatization, Depression, Phobic anxiety, and Additional items ; scores on BI and mRS were associated with scores on Depression, Phobic anxiety and Additional items ; MMSE score was associated with Obsessive-compulsive, Depression, Phobic anxiety, and Additional items ; and grip strength was associated with Somatization, Depression, Anxiety and Additional items. Conclusions : More severe neurological symptoms were associated with higher psychiatric morbidity particularly in depression, phobic anxiety, sleep and appetite disturbance at acute stage of stroke. More intensive psychiatric care and intervention are needed for the high risk group.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.64-70
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• 2006

Purpose : The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. Methods : Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and $Tc^{99m}$-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. Results : Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD <10, 10-19, 20-29, >30 mm, and the operation risk is higher as the APPD is increased. Conclusion : In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.259-264
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• 2003

Purpose : We have performed an analysis on patients who received Rastelli operation in our institute and reviewed their progress postoperatively. Various factors with suspected relationship to the outcome have been considered to help in future treatment and follow-up. Methods : We analyzed retrospectively 43 patients who either received Rastelli operation in Yonsei University Cardiovascular Center from March 1995 to April 1997 or who received post-procedural cardiac catheterization and follow-up echocardiography in the out-patient department after the procedure. Results : No statistically valid relationships were found between the age of the patient, their body weight, preoperative pulmonary arterial index and pressure, presence of pulmonary branchial stenosis and postoperative results. Cases with atrioventricular concordance showed lower age and body weight, and discordant cases exhibited lower ejection fraction 3 days postoperatively. Upon follow up, lower NYHA score was seen in patients with severe residual stenosis. In the group that received cardiac catheterization after the procedure, residual stenosis and right ventricular pressure measurement in echocardiography showed good correlation with the catheterization data. Conclusion : In cases where conduit insertions of the right ventricular outflow tract are required to achieve total correction in complex cardiac deformity, early operation does not seem to provide a clear risk to the patient. In patients with atrioventricular discordance, careful postoperative observation of the ventricular function seems to be needed. Also, echocardiography appears to be a sound method in follow-up of patients after the correctional procedure.

• Journal of Nutrition and Health
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• v.39 no.7
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• pp.624-640
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• 2006

Dialysis patients are at risk of malnutrition not only because of losses of nutrients during peritoneal dialysis but also because of anorexia that results in inadequate nutrient intakes. The aim of this study was to estimate the nutritional status of 154 patients receiving continuous ambulatory peritoneal dialysis (CAPD), especially focused on protein-energy malnutrition and vitamin and mineral status. The mean age of the subjects was $5.12\;{\pm}\;12.4\;y$ with educational years of $12.3\;{\pm}\;0.4\;y$ for male and $9.6\;{\pm}\;0.4\;y$ for female. The mean duration of dialysis was $22.7\;{\pm}\;21.7\;mo$. The causes of renal failure included diabetes (32.7), chronic glomerulonephritis (15.0%), and hypertension (8.5%). The main complications associated with chronic renal failure were hypertension (86.1%), diabetes (35.4%) and liver disease (9.0%). The mean daily energy intake was $1216.8\;{\pm}\;457.3\;kcal$ and increased to $1509.2\;{\pm}\;457.2\;kcal$ when added with the energy from dextrose in dialysate. The latter was still much lower than estimated energy requirement but energy intake per kg of body weight (28.1 kcal/1 g) was within the range of that recommended for CAPD patients' diet therapy (25 - 30 kcal/kg). The average daily intake of protein was $49.2\;{\pm}\;25.1\;g$ with 37.6% of the patients showing their intakes less than Estimated Average Requirement. The average protein intake per kg of weight was 0.9 g/kg, which is less than that recommended for CAPD patients (1.2-1.5g/kg) with mean serum albumin level $3.2\;{\pm}\;0.5\;g/dl$. The proportion of the patients with dietary calcium intake less than EAR was 90.9%, but when added with supplementary calcium (phosphorus binder), most patients showed their total calcium intake between EAR and UL. Fifty percent of the patients were observed with dietary iron intake less than EAR, however most patients revealed their total iron intake with supplementation above UL. The addition of folic acid with supplementation increased mean total folic intake to $1126.0\;{\pm}\;152.4\;{\mu}g$ and ninety eight percent of the subjects showed their total folic acid intake above UL. The prevalence of anemia was 83.1 % assessed with hemoglobin level, even with high intakes of iron with supplementation. Thirty four percent of the patients showed their fasting blood glucose was not under control $(\geq\;126\;mg/dl)$ even with medication or insulin probably due to dextrose from dialysate. The mean blood lipid levels were within the reference levels of hyperlipidemia, but with 72.1 % of the patients showing lower HDL-C. In conclusion, Fairly large proportion of the patients were observed with protein malnutrition with low intake of protein and serum albumin level. Few patients showed their vitamins and minerals intake less than EAR with supplementation. For iron and folic acid, their intakes were increased to above UL for large proportion of he patients. However, more than eighty percent of the patients were still anemic associated with decreased renal function. The serum blood glucose and lipid level were not under control for some patients with medication. It seems that supplementation and medications that patients are taking should be considered for dietary consulting of CAPD patients.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.241-254
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• 2011

Financial time-series forecasting is one of the most important issues because it is essential for the risk management of financial institutions. Therefore, researchers have tried to forecast financial time-series using various data mining techniques such as regression, artificial neural networks, decision trees, k-nearest neighbor etc. Recently, support vector machines (SVMs) are popularly applied to this research area because they have advantages that they don't require huge training data and have low possibility of overfitting. However, a user must determine several design factors by heuristics in order to use SVM. For example, the selection of appropriate kernel function and its parameters and proper feature subset selection are major design factors of SVM. Other than these factors, the proper selection of instance subset may also improve the forecasting performance of SVM by eliminating irrelevant and distorting training instances. Nonetheless, there have been few studies that have applied instance selection to SVM, especially in the domain of stock market prediction. Instance selection tries to choose proper instance subsets from original training data. It may be considered as a method of knowledge refinement and it maintains the instance-base. This study proposes the novel instance selection algorithm for SVMs. The proposed technique in this study uses genetic algorithm (GA) to optimize instance selection process with parameter optimization simultaneously. We call the model as ISVM (SVM with Instance selection) in this study. Experiments on stock market data are implemented using ISVM. In this study, the GA searches for optimal or near-optimal values of kernel parameters and relevant instances for SVMs. This study needs two sets of parameters in chromosomes in GA setting : The codes for kernel parameters and for instance selection. For the controlling parameters of the GA search, the population size is set at 50 organisms and the value of the crossover rate is set at 0.7 while the mutation rate is 0.1. As the stopping condition, 50 generations are permitted. The application data used in this study consists of technical indicators and the direction of change in the daily Korea stock price index (KOSPI). The total number of samples is 2218 trading days. We separate the whole data into three subsets as training, test, hold-out data set. The number of data in each subset is 1056, 581, 581 respectively. This study compares ISVM to several comparative models including logistic regression (logit), backpropagation neural networks (ANN), nearest neighbor (1-NN), conventional SVM (SVM) and SVM with the optimized parameters (PSVM). In especial, PSVM uses optimized kernel parameters by the genetic algorithm. The experimental results show that ISVM outperforms 1-NN by 15.32%, ANN by 6.89%, Logit and SVM by 5.34%, and PSVM by 4.82% for the holdout data. For ISVM, only 556 data from 1056 original training data are used to produce the result. In addition, the two-sample test for proportions is used to examine whether ISVM significantly outperforms other comparative models. The results indicate that ISVM outperforms ANN and 1-NN at the 1% statistical significance level. In addition, ISVM performs better than Logit, SVM and PSVM at the 5% statistical significance level.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.441-446
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• 2009

Background: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery in-creases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniquesi.e., Heartstring system versus aortic side clamping in off pump coronary bypassing' surgery (OPCAB). Material and Method: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. Result: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the. Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group land 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. Conclusion: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the. absence of embolic stroke maybe a definite benefit which may be better defined through further studies over a larger cohort.

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.693-703
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• 2001

Background : Smoking is the most important and consistent determinant of the development and progression of COPD(Ed Note : Define COPD). The fact that cigarette smokers develop a different type of COPD, chronic bronchitis and emphysema, with different clinical and pathological aspects, suggests that the development of COPD has a relationship with other smoking-associated factors beyond just a simple smoking history. The aim of this was to analyze the smoking habits and history of patients with COPD and to evaluate the development of different types of COPD according to patient's smoking habits. Method : To evaluate the differences in the smoking patterns of patients with chronic bronchitis and emphysema, a pulmonary function test was conducted, and the smoking history and patterns was obtained through a smoking history questionnaire by a direct personal interview from 333 male cigarette smokers diagnosed with COPD, in the Yeungnam university medical center(190 patients diagnosed with chronic bronchitis, 143 patients diagnosed with emphysema). Result : The patients with emphysema smoked earlier and had a higher smoking history(ie, more packyears, more total amounts of smoked cigarette, and more deep inhalation and longer duration of plain cigarette exposure) than those with chronic bronchitis. The depth of inhalation was also significantly higher in the emphysema patients after taking into account age, cumulative cigarette consumption and the type of cigarette smoked. Conclusion : Emphysema was more associated with the increasing degree of inhalation as assessed by the depth of inhalation. A high alveolar smoke exposure may be a significant risk factor for the development of emphysema.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.3
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• pp.317-326
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• 2011

The mental foramen and anterior loop of the mandibular canal are important landmarks for mandibular surgical procedures. The purpose of this study was to analyze the shape and position of the mental foramen and anterior loop of the mandibular canal on the computed tomography (CT) images, and apply the results clinically. CT images of 96 patients (33 male, 36 female, age range 17~43 years, mean $24.6{\pm}4.99$ years) were enrolled. The horizontal and vertical position of the mental foramen, as well as the distance from the root apices were measured. The distance of the anterior loop of the mandibular canal to the root apices, and the buccal angle were measured. The mental foramen was found mostly below the second premolar observed in 81 cases (46.0%), between the first and second premolars in 67 cases (38.0%), and between the second premolar and first molar in 19 cases (10.2%). The mean distance between the mental foramen and the lower border of the mandible was $12.20{\pm}1.77$ mm, the mean distance between the mental foramen and root apex was $5.16{\pm}0.98$ mm. The mean distance of the anterior loop of the mandibular canal was $5.80{\pm}2.00$ mm. The buccal angle measured at $47.7{\pm}9.07^{\circ}$. The distance between the root apex and mental foramen measured as $5.16{\pm}0.98$ mm on panoramic radiography, and $6.2{\pm}3.07$ mm on CT. The mean distance between the mental foramen and mandibular canal was $5.39{\pm}1.62$ mm. When performing surgical procedures such as installing dental implants, it is important to minimize surgical trauma, especially the risk of damage to the mental nerve. To optimize the surgical outcome, a careful assessment of the shape and position of the mental foramen and the anterior loop of the mandibular canal must be made. CT images are useful for finding such anatomic structures.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.359-371
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• 2010

Facial asymmetry has been found with a higher frequency (70~84%) in skeletal class III malocclusion patients. Anticipating the poor prognosis of prosthesis due to malocclusion, occlusal stability must be obtained by orthodontic treatment. Moreover, orthodontic surgery would be needed in some severe cases for better functional and esthetic results. The orthognathic surgery is performed on one jaw or two jaw depending on the results of facial diagnosis. Genioplasty may change the vertical, horizontal, sagittal position of chin by osteotomy or augmentation using implants, also. This case is about a 24 year-old male patient who visited our clinic to solve the facial asymmetry and mandibular prognathism. Skeletal class III malocclusion, maxillary canting and menton deviation to left by 13 mm were detected. Multiple ill-fitting prostheses, unesthetic maxillary anterior prostheses, and several dental caries were found. After pre-operative orthodontic treatment, Le-Fort I osteotomy, sagittal split ramus osteotomy, genioplasty, right mandibular angle augmentation were done for the correction of jaw relation and asymmetry. By diagnostic wax-up after post-operative orthodontic treatment, maxillary full mouth rehabilitation and mandibular posterior restorations were planned out. For better result, clinical crown lengthening procedure was done on #11, 12 and implant was placed on left mandibular first molar area. The patient was satisfied with the final prostheses. Because of his high caries risk, long-term prognosis will depend on the consistent maintenance of oral hygiene and periodic follow-up.