• Radiation Oncology Journal
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• v.25 no.2
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• pp.93-100
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• 2007

[ $\underline{Purpose}$ ]: To evaluate the outcome and prognostic factors of postoperative radiotherapy in endometrial carcinoma. $\underline{Materials\;and\;Methods}$: From September 1991 to August 2003, 76 patients with endometrial carcinoma received postoperative adjuvant radiotherapy after hysterectomy at Asan Medical Center. Stage was classified as FIGO I in 41 (53.9%), II in 12 (53.9%), and III in 23 (30.3%). Histologic grade 1, 2 and 3 were in 29 (38.2%), 20 (26.3%), and 27 (35.5%) respectively. Forty two patients received both external beam radiation therapy (EBRT) and intracavitary radiation (ICR), 34 patients were treated with EBRT or ICR alone. EBRT dose was 50.4 Gy, ICR was performed in $4{\sim}6$ fractions with $4{\sim}5\;Gy$ per fraction. Median follow-up period was 51 (range $5{\sim}121$) months. $\underline{Results}$: Five-year overall survival was 89.6%. In univariate analysis, statistically significant factors to overall survival were FIGO stage, lymph node metastasis and histologic grade. In disease free survival, FIGO stage, lymph node metastasis and lymphovascular invasion were significant prognostic factors. Recurrence was seen in 11 patients. Of these, systemic failure was in 10 patients. There were no moderate to severe complications after radiation therapy. $\underline{Conclusion}$: The outcome of postoperative adjuvant radiotherapy in endometrial carcinoma was good. Main pattern of failure after postoperative radiotherapy was distant metastasis. So, adjuvant chemotherapy may help in improving outcome. Further study on chemotherapy in combined with postoperative radiotherapy will be needed, especially for patients with high risk factors such as high FIGO stage, lymphovascular invasion, and high histologic grade.

• Neonatal Medicine
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• v.16 no.2
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• pp.213-220
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• 2009

Purpose: Hearing loss is one of the common birth defects in humans, with a reported prevalence of 1-3 per 1000 newborns. We investigated the incidence of hearing loss and evaluated the use of neonatal hearing screening test in neonatal intensive care unit (NICU) graduates who are at greater risk for hearing loss than normal newborns. Methods: The neonates admitted to the NICU of Asan Medical Center from 1 March, 2003 to 30 March, 2008 who were available for follow-up were included. Those who failed the first auditory brainstem response prior to discharge were retested with the stapedial reflex test, auditory brainstem response and tympanometry in the Otolaryngology department. Results: Of 2,137 neonates, 2,000 (93.5%) neonates were tested prior to discharge. Sixty-seven neonates (3.4%) failed the first newborn hearing screening test. Of 67 infants, 52 infants were retested for a second hearing test. Excluding 10 infants (19.2%) who were lost during follow-up, 16 infants were confirmed to have hearing impairment of which 12 and 4 infants had unilateral and bilateral hearing loss, respectively. Of 16 infants, 5 did not meet the criteria set by the Korean National Health Insurance Corporation. Conclusion: The prevalence of hearing impairment in NICU graduates is about 0.8%, excluding those who were lost for follow up, necessitating a systemic and effective hearing assessment program among these high risk infants and more generous national insurance coverage.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.210-217
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• 2006

Purpose: Crohn disease (CD) in children is frequently complicated by malnutrition and growth retardation. Conventional treatment with corticosteroid may also affect the growth of children, which may be alleviated by nutritional therapy. Therefore, we performed this study to evaluate the role of nutritional therapy in the treatment of CD in children. Methods: The study cohort consisted of thirty children under the age of 17 years, admitted to the Asan Medical Center from 2001 to 2005. While 11 children received nutritional therapy (NT) with an elemental diet, 19 received conventional corticosteroid therapy (ST). Comparative analysis was performed for the rate of the induction of remission, recurrence, disease activity index of pre and post-treatment, and changes of the growth using mean standard deviation score for weight (zW) and height (zH). Results: Ten of 11 children with NT and 18 of 19 children with ST completed the therapy. Two of them were lost to follow-up during the treatment. All 10 children with NT and 15 of 18 children with ST achieved remission. While there was no recurrence in children with NT, 7 with ST showed recurrence within 1 year. Pre- and post treatment Pediatric Crohn disease Activity Index (PCDAI) did not show a difference between the two groups. There were no differences in zW and zH between the two groups after 1 year of follow-up. Conclusion: This study showed that nutritional therapy could be considered instead of steroid therapy for treatment of children with CD. However, a long-term study will be needed to determine the long-term efficacy.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.323-343
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• 2018

This study defines the mineralogical, micro-textural and geochemical characteristics for the carbonate rocks and discusses the fluids that have affected the depositional environment of the Lower Makgol Formation in Seokgaejae section. Based on analysis of X-ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-ray Spectrometry (SEM-EDS), Electron Probe Micro Analyzer-Wavelength Dispersive X-ray Spectrometry (EPMA-WDS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), carbonate miorofacies in the basal and the lower members of the Makgol Formation are distinguished and classified into four types. Type 1 dolomite (xenotopic interlocking texture) and Type 2 dolomite (idiotopic interlocking texture) have relatively high Mg/Ca ratio, flat REE pattern, low Fe and Mn. Extensively interlocking textures in these dolomites indicate constant supply of Mg ion from hypersaline brine. Type 3 and Type 4 dolomite (scattered and loosely-aggregated texture) have relatively moderate Mg/Ca ratio, MREE enriched pattern, low to high Fe and Mn. These partial dolomitization indicate limited supply of Mg ion under the influx of meteoric water with seawater. Also, the evidence of Fe-bearing minerals, recrystallization and relatively high Fe and Mn in Type 4 indicates the influence of secondary diagenetic fluids under suboxic conditions. Integrating geochemical data with mineralogical and micro-textural evidence, the discrepancy between the basal and the lower members of the Makgol Formation indicates different sedimentary environment. It suggest that hypersaline brine have an influence on the basal member, while mixing meteoric water with seawater have an effect on the lower member of the Makgol Formation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.15-24
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• 2015

$CH_4$ is a trace gas and one of the key greenhouse gases, which requires continuous and systematic monitoring. The application of eddy covariance technique for $CH_4$ flux measurement requires a fast-response, laser-based spectroscopy. The eddy covariance measurements have been used to monitor $CO_2$ fluxes and their data processing procedures have been standardized and well documented. However, such processes for $CH_4$ fluxes are still lacking. In this note, we report the first measurement of $CH_4$ flux in a rice paddy by employing the eddy covariance technique with a recently commercialized wavelength modulation spectroscopy. $CH_4$ fluxes were measured for five consecutive days before and after the rice transplanting at the Gimje flux monitoring site in 2012. The commercially available $EddyPro^{TM}$ program was used to process these data, following the KoFlux protocol for data-processing. In this process, we quantified and documented the effects of three key corrections: (1) frequency response correction, (2) air density correction, and (3) spectroscopic correction. The effects of these corrections were different between daytime and nighttime, and their magnitudes were greater with larger $CH_4$ fluxes. Overall, the magnitude of $CH_4$ flux increased on average by 20-25% after the corrections. The National Center for AgroMeteorology (www.ncam.kr) will soon release an updated KoFlux program to public users, which includes the spectroscopic correction and the gap-filling of $CH_4$ flux.

• Tuberculosis and Respiratory Diseases
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• v.53 no.2
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• pp.173-182
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• 2002

Background : Nontuberculous mycobacteria (NTM) have usually been considered to be contaminants of colonizers when isolated from respiratory specimens in Korea, where there is a high prevalence of tuberculosis and a low rate of HIV infections. Therefore, there has been few studies on the clinical significance of NTM species in immunocompetent patients were investigated. Methods : Thirty-five NTM isolates, for which species identification was requested by the treating physicians during 1999 at the Asan Medical Center, were retrospectively analyzed. They were identified to the species level by mycolic acid analysis using high-performance liquid chromatography. The medical records of the patients with the NTM isolates were reviewed to identify those patients who met the American Thoracic Society (ATS)'s criteria for mycobacterial pulmonary infection. Their antimicrobial susceptibility data were compared with the clinical outcomes. Results : The NTM were identified as M. intracellulare (6 isolates), M. avium (5), M. abscessus (5), M. gordonae (5), M. terrae complex (4), M. szulgai (2), M. kansasii (2), M. fortuitum (2), M. peregrinum (1), M. mucogenicum (1), M. celatum (1), and M. chelonae (1). All 35 patients showed clinical symptoms and signs of chronic lung disease, but none had a HIV infections; 16 (45.7%) patients were found to be compatible with a NTM pulmonary infection according to the ATS criteria, 5 and 4 cases were affected with M. intracellulare and M. abscessus, respectively; 8 patients had a history of pulmonary tuberculosis. 13 patients received antimycobacterial therapy for an average of 21 months and 9 patients were treated with second-line drugs. Only 4 patients had improved radiologically. Conclusion : A NTM should be considered a potential pathogen of pulmonary infections in immunocompetent patients with chronic pulmonary diseases. Most NTM infections were left untreated for a prolonged period and showed a poor outcome as a result, M. intracellulare and M. abscessus were the two most frequent causes of NTM pulmonary infections in this study. Species identification and antimycobacterial susceptibility tests based on the species are needed for the optimum management of a NTM pulmonary infection in patients.

• Tuberculosis and Respiratory Diseases
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• v.59 no.5
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• pp.487-496
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• 2005

Background : 'Major pulmonary thromboembolism' is defined as right ventricular (RV) dysfunction, with or without shock, accompanied by significant morbidity and mortality. In this study, those with major pulmonary thromboembolism were divided into the shock and RV dysfunction only groups, and then investigated the mortality and complications in thrombolysis or anticoagulation, respectively. Methods : In a retrospective study, between January 1995 and December 2004, 60 eligible patients with a major pulmonary thromboembolism, admitted in Asan Medical Center, were included. Results : A total of 57 patients were treated with medical therapy. Thrombolysis was performed in 13 patients (23%) and anticoagulation in 44 (77%). There were no differences in the APACHEII and SOFA scores between the two groups. 6 (46%) and 11 (25%) patients died in the thrombolysis and anticoagulation groups, respectively (p=0.176). In the 19 patients (33%) showing shock, thrombolysis was performed in 9 (47%) and anticoagulation in 10 (53%). 4 (44%) of the 9 patients treated with thrombolytic agents and 3 (30%) of the 10 treated with anticoagulants died (p=0.650). In the 38 patients (67%) showing RV dysfunction only, thrombolysis was performed in 4 (11%) and anticoagulation in 34 (89%). 2 (50%) of the 4 patients treated with thrombolytics and 8 (24%) of the 34 treated with anticoagulants died (p=0.279). Three patients (23%) who underwent thrombolysis had a major bleeding episode, compared with 2 (5%) who were treated with anticoagulants (p=0.072). Conclusion: The results of our study showed that thrombolysis did not lower mortality and tended to increase major bleeding compared with anticoagulation in both the shock and RV dysfunction only groups. Further evaluation of the efficacy and safety of thrombolytic therapy for major thromboembolism appears warranted in Korea.

• Tuberculosis and Respiratory Diseases
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• v.60 no.1
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• pp.38-43
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• 2006

Background : Even though two-month rifampicin (RMP, R) and pyrazinamide (PZA, P) treatment has some advantages over isoniazid (INH, H) treatment for latent tuberculosis infection (LTBI), it was withdrawn from the list of treatment regimens for LTBI because of reported cases of severe hepatotoxicity. The purpose of this study was to estimate the frequency of hepatotoxicity of RMP and PZA treatment excluding INH in a Korean population. Method : TIn order to recruit patients who were prescribed RMP and PZA excluding INH, 256 INH-resistant tuberculosis patients were investigated through retrospective medical record analysis. A standard four-drug regimen was changed to a RMP/PZA-containing regimen excluding INH in 64 patients (RZ+ group). In the same study period, 146 patients who were prescribed an INH/RMP/PZA-containing standard regimen were randomly selected as a control (HRZ+ group). Clinical characteristics including liver diseases and the frequency of drug-induced hepatitis were compared between the RZ+ and HRZ+ groups. Result : The mean age of patients in the RZ+ group was 50.2 (${\pm}16.2$) and the male-to-female ratio was 36:28. The frequency of underlying liver diseases was 10.9% (7/64), which was not significantly different from that of the HRZ+ group (4.1%, 6/146). Even though the treatment duration of RZ+ ($5.5{\pm}4.8months$) was longer that than that of HRZ+ ($2.7{\pm}2.3months$), the frequency of toxic hepatitis was not significantly different between RZ+ and HRZ+ groups, 3.5% (2/57) and 7.1% (10/140), respectively. Conclusion : Hepatotoxicity was mild and occurred in a minor proportion of patients in a Korean population prescribed an RMP/PZA-containing regimen. A future prospective study including more patients is needed.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.98-105
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• 2004

Purpose : To evaluate whether positron omission tomography (PET) with 2-[F-18]fluoro-2-deoxy-D-giucose(FDG) can be used to predict of early response to definitive aim radlotherapy (RT) in squamous cell carcinoma of the head and neck using response rate and locoreglonal control as study endpoints. Materials and Methods : Twenty-two patients with head and neck cancer underwent a FDG-PET study before RT, after a flrst dose of 45 Gy, and after a second dose on more 4han 70 Gy. Standard uptake value (SUV) was calculated for primary tumor (n=22) and neck lymph node (n:10). Attenuation corrected PET scans acquired 60 min after tracer injection were used for evaluation of FDG uptake In tumors. A quantitative FDG uptake index was expressed as Suvlean (corrected for iean body mass). The follow-up time was at least 5 months (range S-1 S months). Results : A total of 22 primary tumors and 10 metastatic lymph nodes were analyzed In FDG-PET. In the first PET study the mean SUVlean the primary tumors and nodes were 5.4 (SD, 2.5) and 4.6 (SD, 2.3), respectively. In the second PET, study peformed after 46 Gy RT the mean SUV in primary tumor and node decreased to 2.9 (SD, 1.9, p<0.001) and 1.7 (SD, 1.3) respectively. in the third PET study peformed at the full dose (more than 70 Gy), RT the mean SUV In the primary tumors and nodes decreased to 2.3 (SD, 1.5, p<0.001) and 1.5 (SD, 1 .1) respectively. Conclusions: FDG uptake In tumors showed a significant decrease after the 45 Gy and more than 70 Gy of RT for squamous cell carcinoma of the head and neck. Reduction of metabolic activity after 46 Gy of radiotherapy Is closely correlated with radiation response.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.1-8
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• 2005

Purpose : The objective of this study was to determine whether the expressions of the two components of DNA-dependent protein kinase, Ku70 and DNA-PKcs, influence the response to radiotherapy (RT) and outcome of treatment of non-disseminated nasopharyngeal carcinoma (NPC) in patients who received definitive RT. Materials and Methods : Sixty-six patients with NPC who were treated with radiotherapy alone or with concurrent chemotherapy between June 1995 and December 2001 were divided into groups based on the levels of immunoreactivity for Ku70 and DNA-PKcs in pretreatment biopsy specimens. The over-expression of Ku70 or DNA-PKcs groups Included patients whose biopsy specimens showed at least 50% immunopositive tumor cells; patients in which less than 50% of the tumor cells in the biopsy tissues were immunopositive were placed in the low Ku70 and DNA-PKcs groups. The immunoreactivities for Ku70 and DNA-PKcs were retrospectively compared with the sensitivity of the tumor to radiation and the patterns of therapy failure. Univariate analyses were peformed to determine the prognostic factors that influenced locoregional control of NPC. Results : The five-year locoregional control rate was significantly higher in the low Ku70 group (Ku(-)) (85%) than in the high Ku70 group (Ku(+)) (42%) (p=0.0042). However, there were no differences in the metastases-free survival rates between the two groups (Ku70 (+), 82%; Ku70 (-), 78%; p=0.8672). Univariate analysis indicated that the over-expression of Ku70 surpassed other well-known predictive clinocopathologic parameters as an Independent prognostic factor for locoregionai control. Eighteen of 22 patients who had locoregional recurrences of the tumor displayed an over-expression of Ku70. No significant association was found between the level of DNA-PKcs expression and the clinical outcome. Conclusion : Our data suggest that the level of Ku70 expression can be used as a molecular marker to predict the response to RT and the locoregional control after RT and concurrent chemotherapy in patients with non-disseminated NPC.