• 한국노년학
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• v.39 no.4
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• pp.895-902
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• 2019

This study reviewed the diagnosis accuracy and evaluation criteria of the fall risk assessment questionnaire that proved validity through factor analysis in previous studies. The purpose of this study was to diagnose high-risk groups and propose personal fall risk profiles for the Korean community-dwelling elderly. The participants of this study were 439 elderly people living in S, U, B, and Y cities Korea (mean age 75.0 ± 5.7 years). Receiver operating characteristic analysis was conducted to review the accuracy of the fall risk assessment and evaluation criteria of the FRA. The results showed that the four sub-factors of the FRA: 'Potential for fall', 'Disease and physical symptoms', 'Environment' and 'Physical function', can effectively diagnose the fall risk of the community-dwelling elderly. The evaluation criteria was presented based on the sensitivity and specificity results. In addition, as a result of analyzing the patterns by the sub factors of the fall risk, the high-risk group accounted for 80% of the elderly who had problems with two or more factors. Therefore, the four sub-factors of FRA can effectively diagnose the fall risk level, and could be present individual fall risk profiles based on the evaluation criteria.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.77-88
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• 2022

Objective: Our study aimed to evaluate the quality of radiomics studies on brain metastases based on the radiomics quality score (RQS), Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist, and the Image Biomarker Standardization Initiative (IBSI) guidelines. Materials and Methods: PubMed MEDLINE, and EMBASE were searched for articles on radiomics for evaluating brain metastases, published until February 2021. Of the 572 articles, 29 relevant original research articles were included and evaluated according to the RQS, TRIPOD checklist, and IBSI guidelines. Results: External validation was performed in only three studies (10.3%). The median RQS was 3.0 (range, -6 to 12), with a low basic adherence rate of 50.0%. The adherence rate was low in comparison to the "gold standard" (10.3%), stating the potential clinical utility (10.3%), performing the cut-off analysis (3.4%), reporting calibration statistics (6.9%), and providing open science and data (3.4%). None of the studies involved test-retest or phantom studies, prospective studies, or cost-effectiveness analyses. The overall rate of adherence to the TRIPOD checklist was 60.3% and low for reporting title (3.4%), blind assessment of outcome (0%), description of the handling of missing data (0%), and presentation of the full prediction model (0%). The majority of studies lacked pre-processing steps, with bias-field correction, isovoxel resampling, skull stripping, and gray-level discretization performed in only six (20.7%), nine (31.0%), four (3.8%), and four (13.8%) studies, respectively. Conclusion: The overall scientific and reporting quality of radiomics studies on brain metastases published during the study period was insufficient. Radiomics studies should adhere to the RQS, TRIPOD, and IBSI guidelines to facilitate the translation of radiomics into the clinical field.

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.540-547
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• 2006

Background : Vital stability and right side heart failure are major prognostic factors of acute pulmonary thromboembolism. While it is important to recognize right side heart failure, it is often difficult in real practice. Recently, several studies have described early diagnostic tools for detecting right side heart failure including echocardiography and biochemical markers. This study, we evaluated the prognostic role of the B-type natriuretic peptide (BNP) in an acute pulmonary thromboembolism. Methods : Thirty-four patients with a diagnosis of acute pulmonary thromboembolism were enrolled in the study. The BNP levels were measured and echocardiography was performed at the Emergency Department. Data on the prognostic factors including ventilatory support, vital stability, pulmonary artery pressure, degree of tricuspid valve regurgitation, complications and death was collected from the patients' medical records. The patients with an acute pulmonary thromboembolism were divided into two groups based on the vital stability and the BNP level and the cutoff values and prognostic factors of the two groups were compared. Results : The predictors of the vital stability that influence the prognosis of patients with acute pulmonary thromboembolism were the BNP level, ventilatory support and death. The plasma BNP levels showed a strong correlation with the vital stability, ventilatory support, thrombolytic therapy and death. When the BNP cutoff level was set to 377.5 pg/dl in a ROC curve, the sensitivity and the specificity for differentiating between the groups with stable or unstable vital signs was 100% and 90%, respectively. Conclusion : This study indicates that a measurement of the plasma BNP levels may be a useful prognostic marker in patients with an acute pulmonary thrombo-embolism.

• Tuberculosis and Respiratory Diseases
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• v.59 no.6
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• pp.625-630
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• 2005

Background : Determining the cause of an exudative pleural effusion is sometimes quite difficult, especially between malignant and tuberculous effusions. Twenty percent of effusions remain undiagnosed even after a complete diagnostic evaluation, including pleural biopsy. The activity of tumor necrosis factor-alpha (TNF-${\alpha}$), which is the one of proinflammatory cytokines, is increased in both infectious and malignant effusions. The aim of this study was to investigate the diagnostic efficiency of TNF-${\alpha}$ activity in distinguishing tuberculous from malignant effusions. Methods : 46 patients (13 with malignant pleural effusion, 33 with tuberculous pleural effusion) with exudative pleurisy were included. TNF-${\alpha}$ concentrations were measured in the pleural fluid and serum samples using an enzyme-linked immunosorbent assay (ELISA). In addition, TNF-${\alpha}$ ratio (pleural fluid TNF-${\alpha}$ : serum TNF-${\alpha}$) was calculated. Results : TNF-${\alpha}$ concentration and TNF-${\alpha}$ ratio in the pleural fluid were significantly higher in the tuberculous effusions than in the malignant effusions (p<0.05). However, the serum levels of TNF-${\alpha}$ in the malignant and tuberculous pleural effusions were similar (p>0.05). The cut off points for the pleural fluid TNF-${\alpha}$ level and TNF-${\alpha}$ ratio were found to be 136.4 pg/mL and 6.4, respectively. The sensitivity, specificity and area under the curve were 81%, 80% and 0.82 for the pleural fluid TNF-${\alpha}$ level (p<0.005) and 76%, 70% and 0.72 for the TNF-${\alpha}$ ratio (p<0.05). Conclusion : We conclude that pleural fluid TNF-${\alpha}$ level and TNF-${\alpha}$ ratio can distinguish a malignant pleural effusion from a tuberculous effusion, and can be additional markers in a differential diagnosis of tuberculous and malignant pleural effusion. The level of TNF-${\alpha}$ in the pleural fluid could be a more efficient marker than the TNF-${\alpha}$ ratio.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.135-143
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• 1994

Background: The cell mediated immunity has an important role in the pathogenesis of tuberculosis. sIL-2R has been known as a sensitive marker of T lymphocyte activation Elevated serum levels of sIL-2R have been found in patients with lymphoproliferative disorders, organ transplantation, autoimmune diseases, and various granulomatous diseases. Elevated levels of sIL-2R have been also found in the serum and pleural fluid of the patients with tuberculosis. To evaluate the diagnostic value of sIL-2R in the differentiation of tuberculous pleurisy and nontuberculous pleurisy. We measured the level of sIL-2R in the sera and pleural fluids of 12 patients with tuberculous pleurisy and 32 patients with nontuberculous pleurisy. Method: Samples of pleural fluid and serum were centrifuged at 2500 rpm for 10 min to remove cell pellets. Soluble IL-2R was measured with a sandwitch enzyme immunoassay using the Cellfree(r) Interleukin-2 Receptor Test kit(T-cell science,Inc. Cambridge, MA). Results: The results obtained were as follows: 1) The sIL-2R level in pleural fluid of the patients with tuberculous pleurisy was higher than that of patients with nontuberculous pleurisy(P<0.005). 2) When the sIL-2R level above 5,000 u/ml in pleural fluid was used as the cut-off value to diagnose tuberculous pleurisy, it had a sensitivity of 84.6% and a specificity of 90.9%. 3) The sIL-2R level in the sera of the patients with tuberculous pleurisy was higher than that of patients with bacterial pleural effusions and normal control group(P<0.05) and there was no difference of levels compared with malignant pleural effusions and transudative pleural effusions(P>0.05). 4) In patients with tuberculous pleurisy, the mean concentration of sIL-2R in pleural fluid was higher than that in serum(P<0.005). Conclusion: These findings suggest that the measurement of elevated levels of pleural fluid sIL-2R in tuberculous pleurisy may be useful in the differential diagnosis between patients with tuberculous pleurisy and nontuberculous pleurisy.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.175-184
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• 1996

Purpose : This study was intended to measure seropositivities and the levels of mumps- and rubella-specific IgG of MMR vaccinees over 17 months of age in Korea. Materials and Methods : From June 1994 to April 1995 we obtained sera from visitors of well baby clinic and patients in Korea University Hospital, who were MMR vaccinees over 17 months of age and had no evidence of immunodeficiency. These 275 study population include 145 males and 130 females. Mumps- and rubella-specific IgG antibody levels were measured by ELISA. Cut-off values for seropositivity were 20 GU(Gamma Unit) in mumps and 0.17 in rubella. Results : 1) As age increased, seropositivities of mumps-specific IgG increased significantly, being 69.0% in 1.5~2 year, 75.0% in 3~4 year, 76.0% in 5~6 year, 90.0% in 7 year, 100% in 8 year, 96.9% in 9 year, 97.4% in 10 year, 97.4% in 11 year, and 96.6% in 12 year of age(p<0.001). 2) As age increased, the levels of mumps-specific IgG antibody(mean${\pm}$standard deviation, GU) increased significantly, being $64.9{\pm}66.5$ in 1.5-2 year, $117.7{\pm}126.4$ in 3~4 year, $152.3{\pm}147.1$ in 5~6 year, $194.3{\pm}168.2$ in 7 year, $258.1{\pm}190.6$ in 8 year, $193.1{\pm}130.1$ in 9 year, $225.7{\pm}119.6$ in 10 year, $220.7{\pm}114.3$ in 11 year, and $222.3{\pm}127.1$ in 12 year of age(p<0.001). There was positive correlation between age and mumps-specific antibody level (r=0.3282, p<0.001). 3) As age increased, seropositivities of rubella-specific IgG decreased significantly, being 72.4% in 1.5~2 year, 75% in 3~4 year, 72% in 5~6 year, 60% in 7 year, 44.4% in 8 year, 40.6% in 9 year, 28.2% in 10 year, 23.1% in 11 year, and 17.2% in 12 year of age(p<0.001). 4) As age increased, rubella-specific IgG decreased significantly, being $0.462{\pm}0.356$ in 1.5~2year, $0.438{\pm}0.306$ in 3~4 year, $0.287{\pm}0.179$ in 5~6 year, $0.204{\pm}0.139$ in 7 year, $0.189{\pm}0.153$ in 8 year, $0.124{\pm}0.121$ in 9 year, $0.093{\pm}0.114$ in 10 year, $0.104{\pm}0.135$ in 11 year, and $0.080{\pm}0.001$ in 12 year of age(p<0.001). There was negative correlation between age and rubella-specific IgG titer (r=-0.551, p<0.001). Conclusions : Eventhough seropositivities and the level of mumps-specific IgG increased as age increased, they are not enough to prevent mumps infection in 1.5 to 6 years of age. Seropositivities and the level of rubella-specific IgG decreased as age increased. Appropriate change in vaccine schedule may be needed to decrease the risks of mumps and rubella infection.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.171-178
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• 2008

Metal filter elements were newly introduced to the high temperature filter(HTF) system in the low- and intermediate-level radioactive waste vitrification plant. In order to evaluate the performance of various metal materials as filter media, elements made of AISI 316L, AISI 904L, and Inconel 600 were included to the test set of filter elements. At the visual inspection to the elements performed after completion of each test, a few dark spots were observed on the surface of some elements. Especially they were found much more at the AISI 316L elements than others. To check the dark spots are the corrosion phenomena or not, two kinds of analyses were performed to the tested filter elements. Firstly, the surfaces or the cross sections of filter specimens cut out from both normal area and dark spot area of elements were analyzed by SEM/EDS. The results showed that the dark spots were not evidences of corrosion but the deposition of sodium, sulfur and silica compounds volatilized from waste or molten glass. Secondly, the ring tensile strength were analyzed for the ring-shape filter specimens cut out from each kind of element. The result obtained from the strength tested showed no evidence of corrosion as well. Conclusionally, depending on the two kinds of analysis, no evidences of corrosion were found at the tested metal filter elements. But the dark spots formed on the surface could reduce the effective filtering area and increase the overall pressure drop of HTF system. Thus, continuous heating inside filter housing up to dew point will be required normally. And a few long-period test should be followed for the exact evaluation of corrosion of the metal filter elements.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.75-80
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• 2005

Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

• Tuberculosis and Respiratory Diseases
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• v.54 no.3
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• pp.320-329
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• 2003

Background : The serum B-type natriuretic peptide (BNP) is released from the ventricles as a response to volume or pressure overload of the ventricles. A few studies have reported that the BNP measurements are useful in differentiating between heart failure and pulmonary causes in patients who visited the emergency department with dyspnea as the chief complaint. It is difficult to differentiate a right heart failure from a left heart failure in the emergency room. However, there is no report on the application of a BNP assay to differentiate in right heart failure from left heart failure. In this study, the BNP levels were measured from dyspneic patients in the emergency department to determine whether or not the BNP level would be useful in differentiating the cause of the dyspnea from right ventricular failure and left ventricular failure. Method : 89 patients who visited emergency department of the Bundang Cha Hospital with dyspnea from June 2002 to March 2003 were selected. The 29 patients from the outpatient clinics and inpatients were randomly selected as the control. Results : The BNP levels of patients in the left heart failure group were significantly different from that of the patients in the right heart failure group ($682{\pm}314$ pg/mL vs. $149{\pm}94$ pg/mL, p=0.000). When the BNP cut-off level was designated as 219 pg/mL using the receiver operating characteristic curve, the sensitivity was 94.3%, and specificity was 92.9%. In addition, the positive predictive value was 97% and the negative predictive value was 86.7% in differentiating right heart failure from left heart failure. Conclusion : Measurements of the serum BNP levels is an accurate and rapid method that can aid in distinguishing between right heart failure and left heart failure.

• Journal of Chest Surgery
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• v.40 no.8
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• pp.552-557
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• 2007

Background: B-type natriuretic peptide (BNP) is a cardiac hormone that is primarily synthesized by the ventricular cardiac myocytes. Increased plasma BNP levels have been observed in patients suffering with congestive heart failure, ventricular hypertrophy and myocaridits and also during heart transplantation rejection. We investigated the serum BNP level as a predictive marker for rejection after heart transplantation. Material and Method: To test the usefulness of measuring the BNP level in cardiac transplant patients, consecutive blood samplings for BNP, right ventricular endomyocardial biopsies, hemodynamic measurements and transthoracic echocardiogram were all done in 10 such patients between January 2004 and August 2005 at the Department of Thoracic and Cardiovascular Surgery in Asan Medical Center. Two groups were identified with using the median value: the low BNP group (n=28, BNP: ${\le}290$ pg/mL) and the high BNP group (n=29, BNP: >290 pg/mL). We retrospectively analyzed rejection, the ejection fraction, tricuspid regurgitation, left ventricular hypertrophy, the pulmonary capillary wedge pressure and the right atrial pressure between the 2 groups. Result: There were no differences in age, gender, rejection, the ejection fraction, tricuspid regurgitation, left ventricular hypertrophy and the right atrial pressure between the 2 groups (p>0.05). However, a higher pulmonary capillary wedge pressure and a higher mean pulmonary atrial pressure were observed in the high BNP group (p<0.05). Further, BNP has linear correlation with the pulmonary capillary wedge pressure (r=0.590, p<0.001). Using the cut-off value of 620 pg/mL, the BNP predicted a high PCWP (>12 mmHg) with a sensitivity of 83.3% and a specificity of 91.1% (AUC: $0.900{\pm}0.045$, p<0.001). Conclusion: The BNP level after heart transplantation does not show any significant correlation with rejection, yet it might be a predictive marker of ventricular diastolic dysfunction.