• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.

• Journal of Chest Surgery
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• v.40 no.9
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• pp.600-606
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• 2007

Background: Infective endocarditis shows high surgical mortality and morbidity rates, especially for aortic endocarditis. This study attempts to investigate the clinical characteristics and operative results of isolated aortic endocarditis. Material and Method: From July 1990 to May 2005, 25 patients with isolated aortic endocarditis (Group I, male female=18 : 7, mean age $43.2{\pm}18.6$ years) and 23 patients with isolated mitral endocarditis (Group II, male female=10 : 13, mean age $43.2{\pm}17.1$ years) underwent surgical treatment in our hospital. All the patients had native endocarditis and 7 patients showed a bicuspid aortic valve in Group I. Two patients had prosthetic valve endocarditis and one patients developed mitral endocarditis after a mitral valvuloplasty in Group II. Positive blood cultures were obtained from 11 (44.0%) patients in Group I, and 10 (43.3%) patients in Group II, The pre-operative left ventricular ejection fraction for each group was $60.8{\pm}8.7%$ and $62.1{\pm}8.1%$ (p=0.945), respectively. There was moderate to severe aortic regurgitation in 18 patients and vegetations were detected in 17 patients in Group I. There was moderate to severe mitral regurgitation in 19 patients and vegetations were found in 18 patients in Group II. One patient had a ventricular septal defect and another patient underwent a Maze operation with microwaves due to atrial fibrillation. We performed echocardiography before discharge and each year during follow-up. The mean follow-up period was $37.2{\pm}23.5$ (range $9{\sim}123$) months. Result: Postoperative complications included three cases of low cardiac output in Group I and one case each of re-surgery because of bleeding and low cardiac output in Group II. One patient died from an intra-cranial hemorrhage on the first day after surgery in Group I, but there were no early deaths in Group II. The 1, 3-, and 5-year valve related event free rates were 92.0%, 88.0%, and 88.0% for Group I patients, and 91.3%, 76.0%, and 76.0% for Group II patients, respectively. The 1, 3-, and 5-year survival rates were 96.0%, 96.0%, and 96.0% for Group I patients, and foo%, 84.9%, and 84.9% for Group II patients, respectively. Conclusion: Acceptable surgical results and mid-term clinical results for aortic endocarditis were seen.

• Clinical and Experimental Pediatrics
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• v.52 no.11
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• pp.1216-1220
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• 2009

Purpose:To analyze and compare various cases in which peritoneal drainage was used as the primary treatment method in preterm infants with intestinal perforation. Methods:Among the preterm infants of less than 28 weeks of gestation who were admitted to the neonatal intensive care unit (NICU) at the Gangnam Severance Hospital from April 2006 to April 2009, 7 who had developed intestinal perforation were studied retrospectively. We investigated the clinical characteristics, secondary operation performances, morbidities, complications, and mortalities. Results:Among the 7 infants, 5 survived. Of the 5 cases, 3 received laparotomy, of which 2 were confirmed as having necrotizing enterocolitis. Of the 2 infants who died, 1 had received laparotomy before 48 h of peritoneal drainage, while the other had not received any subsequent treatment. Of the 7 children, 4 had patent ductus arteriosus (PDA), of which 3 had received indomethacin injection. Five infants had begun enteral feeding before they developed intestinal perforation. Of the 5 infants who survived, 4 were diagnosed with cholestasis. Of the 7 infants, 4 developed periventricular leukomalacia (PVL) and 3 developed rickets. Conclusion:Although the use of peritoneal drainage as the primary management of intestinal perforation in preterm infants is controversial, we suggest that it can be used for treating extreme premature neonates. Further randomized controlled study will be required to determine the feasibility of using this method.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.497-503
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• 2003

Pulmonary aspergillosis usually results from the colonization of the existing lung lesions by chronic pulmonary diseases, such as tuberculosis. Most cases of pulmonary aspergilloma have been treated surgically for many years because it is a potentially life-threatening disease causing massive hemoptysis. Here we reviewed our results from the last 10 years. Material and Method: We reviewed 31 cases surgically treated from Aug. 1992 to Jul. 2002. retrospectively. This investigation is designed to illustrate the peak age incidence, sex ratio, chief complaints, preoperative study, anatomic location of operative site, postoperative pathologic finding and postoperative complications. Result: The peak age Incidence laid in the 3rd and 4th decade of 20 cases (64.5%). The most common complaint was hemoptysis in 27 cases (87.1%). The 31 cases had a history of treatment with anti-tuberculous drugs under impression of pulmonary tuberculosis. The 19 cases (61.3%) showed the so-called “Air-meniscus sign” on the preoperative chest X-ray. In the 31 cases (100%) on the chest computed tomography. as a preoperative diagnostic modality, positivity was shown in 37.9%, 83.3% was shown on the fungus culture of sputum for Aspergillus, serum immunodiffusion test for A. fumigatus, respectively. The anatomical location of aspergilloma was mainly in the upper lobe in 19 cases (61.3%) and the majority of cases were managed by lobectomy. The postoperative pathologic findings showed that 31 cases (100%) were combined with tuberculosis. The postoperative complications include empyema, prolonged air leakage, remained dead space, postoperative bleeding and these numbers of cases is 3 cases (9.7%), 2 cases (6.45%), 2 cases (6.45%), 1 case (3.23%), respectively. one case was died postoperatively due to massive beeding, and asphyxia. Conclusion: Compared with the previous study, there is no significant difference in results. Preoperative chest computed tomography and immunodiffusion test were more commonly available and showed high positivity. Operations often became technically difficult because of pleural space obliteration, indurated hilar structures, and poor expansion of the remaining lung, which were more prominent in the patients with complex aspergillosis. In such cases, medical treatments and interventional procedures like bronchial artery embolization are preferred. However, cavernostomy is also recommanded with few additional morbidity because of its relatively less invassiveness. Early surgical intervention is the recommended management for patients with simple aspergilloma considering the Row surgical mortality and morbidity in recent days.

• Journal of Life Science
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• v.18 no.8
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• pp.1147-1153
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• 2008

The purpose of this investigation was to determine the effect of feeding trans fat on serum and tissue lipid profiles and fatty acid composition in mice. Forty-five male mice aged at 4 weeks were fed on the 10% palm oil (n-3 deficient group), 20% dried mackerel (n-3 adequate group) and 5% trans fat (trans group) for three months. Total triglyceride, cholesterol and LDL-cholesterol levels were increased in serum, liver and heart of the n-3 deficient and trans groups compared with the n-3 adequate group, while liver HDL-cholesterol levels were lowest in the trans group (p<0.05). In liver and heart, trans group showed higher levels of total cholesterol and LDL-cholesterol compared with the n-3 deficient group (p<0.05). In fatty acid compositions of serum, heart, liver and kidney, the intake of trans fat led to increased percentages of 18:1n-9trans and 18:2n-6trans. The trans group showed similar patterns to the n-3 deficient group, except an increased percentage of 18:2n-6cis. Generally, the n-3 deficient and trans groups showed increased percentages of n-6 fatty acids and decreased percentages of n-3 fatty acids, specially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) compared to the n-3 adequate group (p<0.05). These results indicate that intake of trans fat increased total triglyceride, cholesterol and LDL-cholesterol levels, which may affect risk for cardiovascular mortality.

• Journal of Preventive Medicine and Public Health
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• v.36 no.4
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• pp.339-348
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• 2003

Objective : To quantify the economic value of the Sirolimus fluting Stent ($CYPHER^{TM}$) in treating acute coronary heart disease (CMD), and to assist in determining an adequate level of reimbursement for $CYPHER^{TM}$ in Korea. Methods : A decision-analytical model, developed by the Belgium Health Economics Disease Management group, was used to investigate the incremental cost-effectiveness of $CYPHER^{TM}$ versus conventional stenting. The time horizon was five years. The probabilities for clinical events at each node of the decision model were obtained from the results of large, randomized, controlled clinical trials. The initial care and follow-up direct medical costs were analyzed. The initial costs consisted of those for the initial procedure and hospitalization, The follow-vp costs included those for routine follow-up treatments, adverse reactions, revascularization and death. Defending on the perspective of the analysis, the costs were defined as insurance covered or total medical costs (=sum of insurance covered and uncovered medical costs). The cost data were obtained from the administrative data of 449 patients that received conventional stenting from five participating Korean hospitals during June 2002. Sensitivity analyses were peformed for discount rates of 3, 5 and 7%. Since the major clinical advantage of $CYPHER^{TM}$ over conventional stenting was the reduction in the revascularization rates, the economic value of $CYPHER^{TM}$, in relation to the direct medical costs of revascularization, were evaluated. If the incremental cost of $CYPHER^{TM}$ per revascularization avoided, compared to conventional stenting, was no higher than that of a revascularization itself, $CYPHER^{TM}$ would be considered as being cost-effective. Therefore, the maximum acceptable level for the reimbursement price of $CYPHER^{TM}$ making the incremental cost-effectiveness ratio equal to the cost of a revascularization was identified. Results : The average weighted initial insurance covered and total medical costs of conventional stenting were about 6,275,000 and 8,058,000 Won, respectively. The average weighted sum of the initial and 5-year follow-up insurance covered and total medical costs of conventional stenting were about 13,659,000 and 17,353,000 Won, respectively. The estimated maximum level of reimbursement price of $CYPHER^{TM}$ from the perspectives of the insurer and society were $4,126,897{\sim}4,325,161$ and $4,939,939{\sim}5,078,181$ Won, respectively. Conclusion : By evaluating the economic value of $CYPHER^{TM}$, as an alternative to conventional stenting, the results of this study are expected to provide a scientific basis for determining the acceptable level of reimbursement for $CYPHER^{TM}$.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.52-60
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• 2001

Purpose: In young male patients who suffered several kinds of trauma with subsequent suspicious reflex sympathetic dystrophy syndrome, we performed three-phasic bone scan in order to investigate its usefulness. Materials and Methods: Patients with narrow range of age (21-25. mean $22.8{\pm}1.3$, all male) were included with suspicious reflex sympathetic dystrophy syndrome of 12 feet and 5 hands. Only one was bilateral feet case and 16 were ipsilateral (Rt:13, Lt:3). The etiologic traumas were 4 fractures, 4 sprains, 3 blunt trauma, 2 cellulitis, 1 tendon tear, 1 crush injury, 1 overexercise, and 1 unknown. Radiologically 3 showed osteoporotic changes. Three-phasic bone scans were performed $21.2{\pm}7.3wks$ after trauma. Results: According to symptom complex, confirmatory reflex sympathetic dystrophy syndrome 4 cases and suspicious 13 were analyzed. All confirmatory cases (100%) showed increased uptake at delay phase with periarticular accentuation. Of confirmatory 4 cases, 2 showed increased uptake in all three phases (perfusion: P, blood pool: B, and delay: D), and other 2 revealed decreased P but, both increased B and D. Of suspicious 13 cases, 9(69.2%) had increased D (4 periarticular and 5 focal), 2 decreased D, and 2 symmetric D. In 12 foot cases, so-called weight hearing patterns - increased contralateral sole at P and B - were revealed in 7(58.3%). Conclusion: Diffuse periarticular increased uptake at delay phase of three-phasic bone scan was a compatible finding to reflex sympathetic dystrophy syndrome in young male patients whose symptom complex strongly designated post traumatic reflex sympathetic dystrophy syndrome.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.83-90
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• 2011

This study was performed to investigate the effects of ramie (Boehmeria nivea) leaf powder on improvements in lipid metabolism in serum, liver and adipose tissue, and the anti-obesity effect in rats fed a high fat/high cholesterol diet for 4 weeks to induce a hyperlipidemic and obese model rat. Male Sprague-Dawley rats weighting 210 g were divided into four groups; a normal diet group (N), a high fat/high cholesterol diet group (HFC), a high fat/high cholesterol diet with 5% ramie leaf powder group (HFC-RL), and a high fat/high cholesterol diet with 10% ramie leaf powder group (HFC-RH). The body weight gain increased with a high fat/high cholesterol diet, but gradually decreased in the ramie leaf powder fed groups compared with the HFC group. The liver index in the HFC group was highest among the four groups, although the difference was not significant compared with the ramie leaf powder fed groups. The adipose tissues weight in the HFC group was heavier than that of the N group, whereas those of groups fed ramie leaf powder decreased gradually. Alkaline phosphatase activity was not different between the HFC groups, but serum alkaline aminotransferase and lactate dehydrogenase activities decreased significantly after ramie leaf powder feeding. Levels of serum triglyceride, total cholesterol, LDL-cholesterol, atherogenic index and cardiac risk factors tended to decrease in the ramie leaf powder fed groups compared with the HFC group, whereas serum HDL-cholesterol level decreased in the HFC group and markedly increased in the ramie leaf powder fed groups. Levels of triglyceride and total cholesterol in the liver were significantly lower in the ramie leaf powder fed groups than in the HFC group. Levels of triglyceride and total cholesterol in adipose tissues were also lower in the ramie leaves powder fed groups than in the HFC group. The activities of heparinreleasable lipoprotein lipase (LPL) and total-extractable LPL in adipose tissues increased in the HFC group compared to that of the N group, but those of the ramie leaf powder fed groups decreased significantly. These results suggest that ramie leaf powder may improve lipid metabolism in serum, liver and adipose tissue and potentially reduce lipid storage.

• The Korean Journal of Nuclear Medicine
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• v.37 no.6
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• pp.364-373
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• 2003

Purpose: For good quality of myocardial perfusion images, an approximately 30 min to 1 hour of waiting time after radiopharmaceutical injection and ingestion of fatty meal are asked of the patients. The aim of this study was to investigate the shortening of waiting time after radiopharmaceutical injection and improvement of image quality using natural plant extracts that promote bile excretion. Materials and Methods: Ten volunteers participated in protocol 1 (7 men, 3 women; mean age, $24.1{\pm}2.4$ years) and protocol 2 (8 men, 2 women; mean age, $26.1{\pm}2.9$ years), respectively. For the modified method of both protocols, subjects took natural plant extracts 15 minutes before the first injection of $^{99m}Tc$ MIBI without laking fatty meals. Control (Conventional) methods were peformed with intake of a fatty meal 20 to 30 minutes after $^{99m}Tc$ MIBI injection. Results: As the results of protocol 1 and 2, the ratio of myocardial to lung ratio were not different between modified and conventional method. Liver to lung ratio of modified method showed significantly lower value than that of conventional method. In modified method, myocardial to liver ratio was higher persistently. In protocol 2, natural plant extracts took before the first injection of $^{99m}Tc$ MIBI exerted accelerating effect of excretion of bile juice into Intestine until the end of examination. Conclusion: These results represent that natural plant extracts for facilitation of bile excretion before injection of $^{99m}Tc$ MIBI may provide better quality of myocardial perfusion images without the need for preparations such as ingestion of fatty meal within the 2 hours compared with conventional method.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.197-203
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• 2005

Homograft aortic valve replacement (AVR) has many advantages such as excellent hemodynamic performance, faster left ventricular hypertrophy regression, resistance to infection and excellent freedom of thromboembolism. To find out the results of homograft AVR, we reviewed our surgical experiences. Material and Method: Eighteen patients (male female=16 : 2, mean age=39.3$\pm$16.2 years, range: 14$\~$68 years) who underwent homo-graft aortic valve replacement between May 1995 and May 2004 were reviewed. The number of homografts was 20 (17 aortic and 3 pulmonic homografts) including two re-operations. Ten patients had a history of previous aortic valve surgery. Indications for the use of a homograft were native valve endocarditis (n=7), prosthetic valve endocarditis (n=5), or Behcet's disease (n=8). The homograft had been implanted predominantly as a full root except in one patient in the subcoronary position. Result: Mean follow-up was 41.3 $\pm$ 26.2 months. There was one operative mortality. Postoperative complications included postoperative bleeding in 3 patients, and wound infection in 1. There was no late death. Three patients underwent redo-AVR. The etiology of the three reoperated patients was Behcet's disease (p=0.025). Freedom from reoperation was $87.5\pm8.3\%$, $78.8\pm11.2\%$ at 1, 5 years respectively, In patients with infective endocarditis, there was no recurrence of endocarditis. There was no thromboembolic complication. Conclusion: Although longer term follow-up with larger numbers of patients is necessary, the operative and mid-term results for homograft AVR was good when we took into account the operative risks of Behcet's disease or infective endocarditis. Behest's disease was a risk factor for reoperation after the homograft AVR. We think homograft AVR is the procedure of choice, particularly in patients with infective endocarditis.