Ultraviolet Photoelectron Spectroscopy Study of Colossal Magnetoresistive La0.7-xPrxCa0.3MnO₃

Chang-Won Lee,Hoon Koh,Han-Jin Noh,Jong-Hyurk Park,Hyung-Do Kim,Moonsup Han,Se-Jung Oh,Dai Jin Eom,Tae Won Noh 한국진공학회 1999 한국진공학회 학술발표회초록집 Vol.- No.-

Increasing Recovery of Nontuberculous Mycobacteria from Respiratory Specimens over a 10-Year Period in a Tertiary Referral Hospital in South Korea

Koh, Won-Jung,Chang, Boksoon,Jeong, Byeong-Ho,Jeon, Kyeongman,Kim, Su-Young,Lee, Nam Yong,Ki, Chang-Seok,Kwon, O Jung The Korean Academy of Tuberculosis and Respiratory 2013 Tuberculosis and Respiratory Diseases Vol.75 No.5

Background: The number of patients with pulmonary disease caused by nontuberculous mycobacteria (NTM) has been increasing worldwide. The aim of this study was to evaluate long-term trends in the NTM recovery rate from respiratory specimens over a 10-year period in a tertiary referral hospital in South Korea. Methods: We retrospectively reviewed the records of mycobacterial cultures of respiratory specimens at Samsung Medical Center from January 2001 to December 2011. Results: During the study period, 32,841 respiratory specimens from 10,563 patients were found to be culture-positive for mycobacteria. These included 12,619 (38%) Mycobacterium tuberculosis and 20,222 (62%) NTM isolates. The proportion of NTM among all positive mycobacterial cultures increased from 43% (548/1,283) in 2001 to 70% (3,341/4,800) in 2011 (p<0.001, test for trend). The recovery rate of NTM isolates from acid-fast bacilli smear-positive specimens increased from 9% (38/417) in 2001 to 64% (1,284/1,997) in 2011 (p<0.001, test for trend). The proportion of positive liquid cultures was higher for NTM than for M. tuberculosis (p<0.001). The most frequently isolated NTM were Mycobacterium avium-intracellulare complex (53%) and Mycobacterium abscessus-massiliense complex (25%). Conclusion: The recovery rate of NTM from respiratory specimens in South Korea has increased steadily.

Response to Switch from Intermittent Therapy to Daily Therapy for Refractory Nodular Bronchiectatic <i>Mycobacterium avium</i> Complex Lung Disease

Koh, Won-Jung,Jeong, Byeong-Ho,Jeon, Kyeongman,Park, Hye Yun,Kim, Su-Young,Huh, Hee Jae,Ki, Chang-Seok,Lee, Nam Yong,Shin, Sung Jae,Daley, Charles L. American Society for Microbiology 2015 Antimicrobial Agents and Chemotherapy Vol.59 No.8

<P>Intermittent three-times-weekly antibiotic therapy is recommended for the initial treatment of patients with noncavitary nodular bronchiectatic <I>Mycobacterium avium</I> complex lung disease. Although some experts recommend switching from intermittent to daily therapy for patients whose sputum has persistent positive cultures after intermittent therapy, the clinical efficacy of these modifications is unknown. Of 20 patients whose sputum had persistent positive cultures after 12 months of intermittent antibiotic therapy, specimens from 6 patients (30%) achieved a negative culture after a change to daily therapy.</P>

Aurora Kinase A Is a Prognostic Marker in Colorectal Adenocarcinoma

Koh, Hyun Min,Jang, Bo Geun,Hyun, Chang Lim,Kim, Young Sill,Hyun, Jin Won,Chang, Weon Young,Maeng, Young Hee 대한병리학회 2017 Journal of Pathology and Translational Medicine Vol. No.

<P><B>Background</B></P><P>Aurora kinase A (AURKA), or STK15/BTAK, is a member of the serine/threonine kinase family and plays important roles in mitosis and chromosome stability. This study investigated the clinical significance of AURKA expression in colorectal cancer patients in Korea.</P><P><B>Methods</B></P><P>AURKA protein expression was evaluated by immunohistochemistry in 151 patients with colorectal adenocarcinoma using tissue microarray blocks. We analyzed the relationship between clinicopathological characteristics and AURKA expression. In addition, the prognostic significance of various clinicopathological data for progression-free survival (PFS) was assessed. Also we evaluated copy number variations by array comparative genomic hybridization and <I>AURKA</I> gene amplification using fluorescence <I>in situ</I> hybridization in colorectal carcinoma tissues.</P><P><B>Results</B></P><P><I>AURKA</I> gene amplification was found more frequently in the 20q13.2–13.33 gain-positive group than the group with no significant gain on the <I>AURKA</I>-containing locus. AURKA protein expression was detected in 45% of the cases (68/151). Positive staining for AURKA was observed more often in male patients (p = .035) and distally located tumors (p = .021). PFS was shorter in patients with AURKA expression compared to those with low-level AURKA expression (p < .001). Univariate analysis revealed that AURKA expression (p = .001), age (p = .034), lymphatic invasion (p = .001), perineural invasion (p = .002), and TNM stage (p = .013) significantly affected PFS. In a multivariate analysis of PFS, a Cox proportional hazard model confirmed that AURKA expression was an independent and significant prognostic factor in colorectal adenocarcinoma (hazard ratio, 3.944; p < .001).</P><P><B>Conclusions</B></P><P>AURKA could serve as an independent factor to predict a poor prognosis in Korean colorectal adenocarcinoma patients.</P>

Hydrogeochemistry and environmental isotopes of ground water in Jeju volcanic island, Korea: implications for nitrate contamination

Koh, Dong-Chan,Chang, Ho-Wan,Lee, Kwang-Sik,Ko, Kyung-Seok,Kim, Yongje,Park, Won-Bae John Wiley Sons, Ltd. 2005 Hydrological processes Vol.19 No.11

<P>Ground water from springs and public supply wells was investigated for hydrochemistry and environmental isotopes of <SUP>3</SUP>H, <SUP>18</SUP>O and D in Jeju volcanic island, Korea. The wells are completed in a basaltic aquifer and the upper part of hydrovolcanic sedimentary formation. Nitrate contamination is conspicuous in the coastal area where most of the samples have nitrate concentrations well above 1 mg NO<SUB>3</SUB>&bond;N/l. Agricultural land use seems to have a strong influence on the distribution of nitrate in ground water. Comparison of stable isotopic compositions of precipitation and ground water show that ground water mostly originates from rainy season precipitation without significant secondary modification and that local recharge is dominant. <SUP>3</SUP>H concentration of ground water ranged from nearly zero to 5 TU and is poorly correlated with vertical location of well screens. The occurrence of the <SUP>3</SUP>H-free, old ground water is due to the presence of low permeability layers near the boundary of the basaltic aquifer and the hydrovolcanic sedimentary formation, which significantly limits ground water flow from the upper basaltic aquifer. The old ground water exhibited background-level nitrate concentrations despite high nitrate loadings, whereas young ground water had considerably higher nitrate concentrations. This correlation of <SUP>3</SUP>H and nitrate concentration may be ascribed to the history of fertilizer use that has increased dramatically since the early 1960s in the island. This suggests that <SUP>3</SUP>H can be used as a qualitative indicator for aquifer vulnerability to nitrate contamination. Copyright © 2005 John Wiley & Sons, Ltd.</P>

Clinical impacts of hazardous alcohol use and obesity on the outcome of entecavir therapy in treatment-naïve patients with chronic hepatitis B infection

Won Gil Chung,Hong Joo Kim,Young Gil Choe,Hyo Sun Seok,Chang Wook Chon,Yong Kyun Cho,Byung Ik Kim,Young Yool Koh 대한간학회 2012 Clinical and Molecular Hepatology(대한간학회지) Vol.18 No.2

Background/Aims: The aim of this study was to analyze the clinical impacts of obesity and hazardous alcohol use on the outcome of entecavir (ETV) therapy in chronic hepatitis B (CHB) patients. Methods: The medical records of 88 treatment-naïve patients who were diagnosed with CHB and received ETV between March 2007 and September 2009 were analyzed retrospectively. Body mass index (BMI) values and Alcohol Use Disorders Identifi cation Test (AUDIT) scores were obtained at 6 months after the initiation of ETV (0.5 mg daily) treatment. Results: A BMI of 25 kg/m2 or more was recognized as an indicator of obesity, and a total AUDIT score of 8 or more was recognized as an indicator of hazardous alcohol use. Of the cohort, 24 patients (27.3%) were obese and 17 (19.3%) were hazardous alcohol users. The rate of seroconversion, alanine aminotransferase (ALT) normalization, and hepatitis B virus (HBV)-DNA negativity (<300 copies/mL) at 3, 6, and 12 months of treatment did not differ significantly between the normal-BMI and high-BMI groups. Moreover, the rate of seroconversion and HBV-DNA negativity at 3, 6, and 12 months of treatment did not diff er signifi cantly between the nonhazardous and hazardous alcohol users. However, the frequency of ALT normalization at 12 months was signifi cantly lower among hazardous alcohol users (91.5% vs. 70.6%; P =0.033). Conclusions: Obesity and hazardous alcohol drinking have no significant impact on the outcome of ETV treatment. However, the ALT normalization rate at 12 months after initiation of ETV treatment was signifi cantly lower among the hazardous alcohol users. (Clin Mol Hepatol 2012;18:195-202) Background/Aims: The aim of this study was to analyze the clinical impacts of obesity and hazardous alcohol use on the outcome of entecavir (ETV) therapy in chronic hepatitis B (CHB) patients. Methods: The medical records of 88 treatment-naïve patients who were diagnosed with CHB and received ETV between March 2007 and September 2009 were analyzed retrospectively. Body mass index (BMI) values and Alcohol Use Disorders Identifi cation Test (AUDIT) scores were obtained at 6 months after the initiation of ETV (0.5 mg daily) treatment. Results: A BMI of 25 kg/m2 or more was recognized as an indicator of obesity, and a total AUDIT score of 8 or more was recognized as an indicator of hazardous alcohol use. Of the cohort, 24 patients (27.3%) were obese and 17 (19.3%) were hazardous alcohol users. The rate of seroconversion, alanine aminotransferase (ALT) normalization, and hepatitis B virus (HBV)-DNA negativity (<300 copies/mL) at 3, 6, and 12 months of treatment did not differ significantly between the normal-BMI and high-BMI groups. Moreover, the rate of seroconversion and HBV-DNA negativity at 3, 6, and 12 months of treatment did not diff er signifi cantly between the nonhazardous and hazardous alcohol users. However, the frequency of ALT normalization at 12 months was signifi cantly lower among hazardous alcohol users (91.5% vs. 70.6%; P =0.033). Conclusions: Obesity and hazardous alcohol drinking have no significant impact on the outcome of ETV treatment. However, the ALT normalization rate at 12 months after initiation of ETV treatment was signifi cantly lower among the hazardous alcohol users. (Clin Mol Hepatol 2012;18:195-202)

경로 매칭 알고리즘을 이용한 구조화된 문서의 변화 탐지

이경호(Kyong Ho Lee),변창원(Chang Won Byun),최윤철(Yoon Chul Choy),고견(Kyun Koh) 한국정보과학회 2001 정보과학회논문지 : 데이타베이스 Vol.28 No.4

본 논문에서는 SGML/XML 문서의 구 버전과 신 버전간의 차이를 계산할 수 있는 효율적인 알고리즘을 제안한다. 차이는 구 버전의 문서를 신 버전으로 변환하는데 소요되는 편집 스크립트로 간주할수 있다. 제안된 알고리즘은 상향식과 하향식의 복합적인 접근 방식을 적용한다. 먼저 두 버전을 구성하는 노드간의 대응관계를 상향식으로 생성하며 하향식 너비 우선 탐색을 적용하여 편집 스크립트를 계산한다. 제안된 알고리즘은 모든 노드간의 대응 여부를 모두 조사할 필요가 없기 때문에 대응관계를 보다 빠르게 생성할 수 있다. 또한 삽입, 삭제, 그리고 갱신의 단순한 변화는 물론이고 부트리 이동과 복사의 구조적으로 보다 의미 있는 변화를 탐지할 수 있다. This paper presents an efficient algorithm to compute differences between old and new versions of an SGML/XML document. The difference between the two versions can be considered to be an edit script that transforms one document tree into another. The proposed algorithm is based on hybridization of bottom-up and top-down methods: matching relationships between nodes in the two versions are produced in a bottom-up manner and top-down breadth-first search computes an edit script. Because the algorithm does not need to investigate possible existence of matchings for all nodes, faster matching can be achieved. Furthermore, it can detect more structurally meaningful changes such as subtree move and copy as well as simple changes to the node itself like insert, delete, and update.

Gata6 in pluripotent stem cells enhance the potential to differentiate into cardiomyocytes

( Chang-hwan Yoon ),( Tae-won Kim ),( Seok-jin Koh ),( Young-eun Choi ),( Jin Hur ),( Yoo-wook Kwon ),( Hyun-jai Cho ),( Hyo-soo Kim ) 생화학분자생물학회(구 한국생화학분자생물학회) 2018 BMB Reports Vol.51 No.2

Pluripotent stem cell (PSC) variations can cause significant differences in the efficiency of cardiac differentiation. This process is unpredictable, as there is not an adequate indicator at the undifferentiated stage of the PSCs. We compared global gene expression profiles of two PSCs showing significant differences in cardiac differentiation potential. We identified 12 up-regulated genes related to heart development, and we found that 4 genes interacted with multiple genes. Among these genes, Gata6 is the only gene that was significantly induced at the early stage of differentiation of PSCs to cardiomyocytes. Gata6 knock-down in PSCs decreased the efficiency of cardiomyocyte production. In addition, we analyzed 6 mESC lines and 3 iPSC lines and confirmed that a positive correlation exists between Gata6 levels and efficiency of differentiation into cardiomyocytes. In conclusion, Gata6 could be utilized as a biomarker to select the best PSC lines to produce PSC-derived cardiomyocytes for therapeutic purposes. [BMB Reports 2018; 51(2): 85-91]

Changing Epidemiology of Nontuberculous Mycobacterial Lung Diseases in a Tertiary Referral Hospital in Korea between 2001 and 2015

Ko, Ryoung-Eun,Moon, Seong Mi,Ahn, Soohyun,Jhun, Byung Woo,Jeon, Kyeongman,Kwon, O Jung,Huh, Hee Jae,Ki, Chang-Seok,Lee, Nam Yong,Koh, Won-Jung KOREAN ACADEMY OF MEDICAL SCIENCE 2018 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.33 No.8

<P>This study investigated the changes in the major etiologic organisms and clinical phenotypes of nontuberculous mycobacterial lung disease (NTM-LD) over a recent 15-year period in Korea. The increase of number of patients with NTM-LD was primarily due to an increase of <I>Mycobacterium avium</I> complex (MAC) lung disease (LD). Among MAC cases, the proportion of <I>M. avium</I> increased compared with <I>M. intracellulare</I>, whereas the incidence of <I>M. abscessus</I> complex and <I>M. kansasii</I> LD remained relatively stable. The proportion of cases of the nodular bronchiectatic form increased compared with the fibrocavitary form of NTM-LD.</P>

Transient intubation for surfactant administration in the treatment of respiratory distress syndrome in extremely premature infants

Koh, Ji Won,Kim, Jong-Wan,Chang, Young Pyo The Korean Pediatric Society 2018 Clinical and Experimental Pediatrics (CEP) Vol.61 No.10

Purpose: To investigate the effectiveness of transient intubation for surfactant administration and extubated to nasal continuous positive pressure (INSURE) for treatment of respiratory distress syndrome (RDS) and to identify the factors associated with INSURE failure in extremely premature infants. Methods: Eighty-four infants with gestational age less than 28 weeks treated with surfactant administration for RDS for 8 years were included. Perinatal and neonatal characteristics were retrospectively reviewed, and major pulmonary outcomes such as duration of mechanical ventilation (MV) and bronchopulmonary dysplasia (BPD) plus death at 36-week postmenstrual age (PMA) were compared between INSURE (n=48) and prolonged MV groups (n=36). The factors associated with INSURE failure were determined. Results: Duration of MV and the occurrence of BPD at 36-week PMA were significantly lower in INSURE group than in prolonged MV group (P<0.05), but BPD plus death at 36-week PMA was not significantly different between the 2 groups. In a multivariate analysis, a reduced duration of MV was only significantly associated with INSURE (P=0.001). During the study period, duration of MV significantly decreased over time with an increasing rate of INSURE application (P<0.05), and BPD plus death at 36-week PMA also tended to decrease over time. A low arterial-alveolar oxygen tension ratio (a/APO2 ratio) was a significant predictor for INSURE failure (P=0.001). Conclusion: INSURE was the noninvasive ventilation strategy in the treatment of RDS to reduce MV duration in extremely premature infants with gestational age less than 28 weeks.