1.Molecular Epidemiology of Extended-spectrum β-Lactamase-producing Escherichia coli in South Korea: A Korean Global Antimicrobial Resistance Surveillance System Report
Dokyun KIM ; SungYoung LEE ; Jun Sung HONG ; Min Hyuk CHOI ; Hyun Soo KIM ; Young Ree KIM ; Young Ah KIM ; Young UH ; Kyeong Seob SHIN ; Jeong Hwan SHIN ; Jeong Su PARK ; Kyoung Un PARK ; Soo Hyun KIM ; Jong Hee SHIN ; Jungsik YU ; Seok Hoon JEONG
Annals of Laboratory Medicine 2026;46(1):72-82
Background:
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance.
Methods:
We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed.
Results:
Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55.
Conclusions
Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.
2.Detection Ability of Quality of Life Changes and Responsiveness of the KOQUSS-40 and the EORTC QLQ-C30/STO22 in Patients Who Underwent Gastrectomy: A Prospective Comparative Study
Bang Wool EOM ; Keun Won RYU ; Ji Yeong AN ; Yun-Suhk SUH ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In-Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye-Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Joongyub LEE ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2026;58(1):221-231
Purpose:
The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ).
Materials and Methods:
A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire.
Results:
Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ.
Conclusion
KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.
3.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
4.First report of iron-overload myopathy due to secondary hemochromatosis in a dog
Jae-Hyuk YIM ; Tae-Un KIM ; Woo Jun KIM ; Seulgi BAE ; Sungho YUN ; Su-Min BAEK ; Jin-Kyu PARK
Journal of Veterinary Science 2025;26(1):e3-
and Relevance: Severe necrosis and mild fibrosis were observed in the liver and forelimb skeletal muscles. Based on histological analysis, we diagnosed iron overload myopathy by secondary hemochromatosis. Secondary hemochromatosis with severe muscle atrophy and myositis is very rare, and this is the first report of iron-overload myopathy in a dog.
5.Smoking Experience before Adulthood Is Associated with an Increased Risk of Developing Ulcerative Colitis in Adult Ex-Smokers
Yu Kyung JUN ; Bongseong KIM ; Yonghoon CHOI ; Cheol Min SHIN ; Young Soo PARK ; Nayoung KIM ; Dong Ho LEE ; Kyungdo HAN ; Hyuk YOON
Yonsei Medical Journal 2025;66(1):9-15
Purpose:
Smoking may have a protective role in developing ulcerative colitis (UC) but have the opposite effect on Crohn’s disease (CD). This study aimed to determine the risk of developing inflammatory bowel disease (IBD) according to smoking status and onset age of smoking.
Materials and Methods:
We collected data on the smoking experiences of participants aged 20–39 years who underwent biannual examinations provided by the Korean National Health Screening Program from 2009 to 2012. IBD diagnosis was identified using the National Health Insurance Service. The risk of IBD according to smoking status and onset age of smoking was analyzed after adjusting for major clinical variables.
Results:
During a median 10.59-year follow-up, the risk of UC in ex-smokers was significantly higher than that in non-smokers, and the earlier ex-smokers started smoking, the higher risk of UC [ex-smokers whose onset age of smoking was <20 years, adjusted hazard ratio (aHR) 1.928, 95% confidence interval (CI)=1.649–2.255; 20–24 years, aHR 1.728, 95% CI=1.541–1.939; 25–29 years, aHR 1.676, 95% CI=1.489–1.887; ≥30 years, aHR 1.226, 95% CI=1.010–1.486]. The risk of UC was significantly lower in current smokers whose onset age of smoking was 25–29 years than in non-smokers (aHR 0.825, 95% CI=0.709–0.959). The risk of CD did not differ according to smoking status and onset age of smoking.
Conclusion
Ex-smokers who started smoking at a young age have a high risk of UC, even after adjusting for the smoking amount.
6.Smoking Experience before Adulthood Is Associated with an Increased Risk of Developing Ulcerative Colitis in Adult Ex-Smokers
Yu Kyung JUN ; Bongseong KIM ; Yonghoon CHOI ; Cheol Min SHIN ; Young Soo PARK ; Nayoung KIM ; Dong Ho LEE ; Kyungdo HAN ; Hyuk YOON
Yonsei Medical Journal 2025;66(1):9-15
Purpose:
Smoking may have a protective role in developing ulcerative colitis (UC) but have the opposite effect on Crohn’s disease (CD). This study aimed to determine the risk of developing inflammatory bowel disease (IBD) according to smoking status and onset age of smoking.
Materials and Methods:
We collected data on the smoking experiences of participants aged 20–39 years who underwent biannual examinations provided by the Korean National Health Screening Program from 2009 to 2012. IBD diagnosis was identified using the National Health Insurance Service. The risk of IBD according to smoking status and onset age of smoking was analyzed after adjusting for major clinical variables.
Results:
During a median 10.59-year follow-up, the risk of UC in ex-smokers was significantly higher than that in non-smokers, and the earlier ex-smokers started smoking, the higher risk of UC [ex-smokers whose onset age of smoking was <20 years, adjusted hazard ratio (aHR) 1.928, 95% confidence interval (CI)=1.649–2.255; 20–24 years, aHR 1.728, 95% CI=1.541–1.939; 25–29 years, aHR 1.676, 95% CI=1.489–1.887; ≥30 years, aHR 1.226, 95% CI=1.010–1.486]. The risk of UC was significantly lower in current smokers whose onset age of smoking was 25–29 years than in non-smokers (aHR 0.825, 95% CI=0.709–0.959). The risk of CD did not differ according to smoking status and onset age of smoking.
Conclusion
Ex-smokers who started smoking at a young age have a high risk of UC, even after adjusting for the smoking amount.
7.First report of iron-overload myopathy due to secondary hemochromatosis in a dog
Jae-Hyuk YIM ; Tae-Un KIM ; Woo Jun KIM ; Seulgi BAE ; Sungho YUN ; Su-Min BAEK ; Jin-Kyu PARK
Journal of Veterinary Science 2025;26(1):e3-
and Relevance: Severe necrosis and mild fibrosis were observed in the liver and forelimb skeletal muscles. Based on histological analysis, we diagnosed iron overload myopathy by secondary hemochromatosis. Secondary hemochromatosis with severe muscle atrophy and myositis is very rare, and this is the first report of iron-overload myopathy in a dog.
8.Massive Closures of Pediatric Clinics and an Exodus of Pediatricians in Korea During the COVID-19 Pandemic:What Career Paths Did Closed-Down Pediatricians Choose?
Jin-Won NOH ; Jun Hyuk KOO ; Min-Hee HEO ; Jin Yong LEE
Journal of Korean Medical Science 2025;40(14):e71-
Background:
This study aimed to investigate the size and characteristics of pediatric clinic closure during the coronavirus disease 2019 (COVID-19) period and what career paths pediatricians chose after closure.
Methods:
This study utilized database of the Health Insurance Review and Assessment Service from 2013 to 2022. We examined the trend of the number of pediatric clinics in operation over the past 10 years. Additionally, the study identified factors associated with the closure of pediatric clinics during the COVID-19 pandemic. Furthermore, the affiliations of representatives who closed their clinics during the pandemic were tracked as of December 2022.
Results:
In 2019, there were 2,229 pediatric clinics. During the COVID-19 pandemic, 364 (16.3%) of these clinics closed. Factors associated with the closure of pediatric clinics included pediatricians over the age of 65, operational periods of less than 5 years, and lower levels of medical expenses. As of 2022, among the 364 clinics that closed, 108 pediatricians (29.7%) retired or ceased working, and 127 pediatricians (34.9%) still employed in pediatricrelated healthcare institutions. A concerning phenomenon is that the remaining 129 pediatricians (35.4%) transitioned to unrelated healthcare institutions.
Conclusion
We have identified the magnitude and factors contributing to pediatric clinic closures. A more pressing issue is that over one-third of the pediatricians have transitioned to non-specialty fields following the closure of their clinics. Pediatrics represents a critical and essential medical field. Health authorities must develop strategies to prevent the avoidable collapse and subsequent exodus of pediatricians.
9.Massive Closures of Pediatric Clinics and an Exodus of Pediatricians in Korea During the COVID-19 Pandemic:What Career Paths Did Closed-Down Pediatricians Choose?
Jin-Won NOH ; Jun Hyuk KOO ; Min-Hee HEO ; Jin Yong LEE
Journal of Korean Medical Science 2025;40(14):e71-
Background:
This study aimed to investigate the size and characteristics of pediatric clinic closure during the coronavirus disease 2019 (COVID-19) period and what career paths pediatricians chose after closure.
Methods:
This study utilized database of the Health Insurance Review and Assessment Service from 2013 to 2022. We examined the trend of the number of pediatric clinics in operation over the past 10 years. Additionally, the study identified factors associated with the closure of pediatric clinics during the COVID-19 pandemic. Furthermore, the affiliations of representatives who closed their clinics during the pandemic were tracked as of December 2022.
Results:
In 2019, there were 2,229 pediatric clinics. During the COVID-19 pandemic, 364 (16.3%) of these clinics closed. Factors associated with the closure of pediatric clinics included pediatricians over the age of 65, operational periods of less than 5 years, and lower levels of medical expenses. As of 2022, among the 364 clinics that closed, 108 pediatricians (29.7%) retired or ceased working, and 127 pediatricians (34.9%) still employed in pediatricrelated healthcare institutions. A concerning phenomenon is that the remaining 129 pediatricians (35.4%) transitioned to unrelated healthcare institutions.
Conclusion
We have identified the magnitude and factors contributing to pediatric clinic closures. A more pressing issue is that over one-third of the pediatricians have transitioned to non-specialty fields following the closure of their clinics. Pediatrics represents a critical and essential medical field. Health authorities must develop strategies to prevent the avoidable collapse and subsequent exodus of pediatricians.
10.Triiodothyronine Is Associated with Incidence/Resolution of Steatotic Liver Disease: Longitudinal Study in Euthyroid Korean
Hye In KIM ; Jun Young KIM ; Jung Hwan CHO ; Ji Min HAN ; Sunghwan SUH ; Ji Cheol BAE ; Tae Hyuk KIM ; Sun Wook KIM ; Jong Ryeal HAHM ; Jae Hoon CHUNG
Endocrinology and Metabolism 2025;40(1):135-145
Background:
The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design.
Methods:
This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models.
Results:
During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD.
Conclusion
In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

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