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.Spatiotemporal Remodeling of Enteric Neural Pathways Underlies ColonicDysmotility Following Spinal Cord Injury in Rats
Min Seob KIM ; Sei KIM ; Se Eun HA ; Hyun Seok CHOI ; Myeong Hwan YU ; Jisong YOU ; Dahyun SEON ; Do Hee LEE ; Min Cheol JOO ; Yong Sung KIM ; Suck Chei CHOI ; Joong Goo KWON ; Kyung Sik PARK ; Hyun Jin KIM ; Seungil RO ; Moon Young LEE
Journal of Neurogastroenterology and Motility 2026;32(1):86-98
Background/Aims:
Spinal cord injury (SCI) frequently impairs defecation, severely affecting the quality of life. This study examines compensatory neural remodeling after SCI, focusing on basal colonic contractility, neural responses to electrical field stimulation, and alterations in excitatory cholinergic and inhibitory nitrergic pathways.
Methods:
Female Sprague–Dawley rats underwent either sham surgery or T10 spinal cord transection and were categorized into 3 groups: sham, 1-week post-SCI (acute), and 4-week post-SCI (chronic). Colonic contractility was assessed in an organ bath using electrical field stimulation in the presence of a nitric oxide synthase inhibitor. Neural protein expression was analyzed by immunofluorescence and Western blotting.
Results:
SCI produced region- and time-dependent impairments in colonic contractility, with distinct alterations in the proximal circular and longitudinal muscles across acute and chronic phases. Neural excitability shifted dynamically, showing enhanced excitatory activity in the proximal longitudinal muscle at 1-week and the distal circular muscle at 4-week post-SCI. Protein analysis revealed increased neuronal nitric oxide synthase in the proximal colon, decreasedsoluble guanylyl cyclase in the distal colon, upregulated muscarinic M3 receptor in the proximal colon, and reduced vaso-active intestinal peptide receptor 1 in both proximal and distal regions.
Conclusion
SCI induces spatiotemporal remodeling of excitatory and inhibitory neural pathways, contributing to colonic dysmotility and revealing potential targets for therapeutic intervention.
3.Quantitative Optical Coherence Tomography Angiography Biomarkers Following a Switch to Brolucizumab in Neovascular Age-Related Macular Degeneration
Seungyeon LEE ; Jaehwan CHOI ; Seung-Young YU ; Kiyoung KIM
Korean Journal of Ophthalmology 2026;40(2):159-168
Purpose:
To evaluate functional and anatomical outcomes, including vessel morphology parameters on swept-source optical coherence tomography angiography (SS-OCTA), in eyes with neovascular age-related macular degeneration (nAMD) switched to brolucizumab.
Methods:
This retrospective study included 37 eyes with nAMD that were switched from other anti–vascular endothelial growth factor (anti-VEGF) agents to intravitreal brolucizumab. Best-corrected visual acuity (BCVA), injection intervals, central subfield thickness (CST), pigment epithelial detachment (PED), and presence of retinal fluid were compared between baseline and 12 months after switch. SS-OCTA images were analyzed to quantify macular neovascularization (MNV) area, vessel density, fractal dimension (FD), and lacunarity.
Results:
Switching to brolucizumab significantly extended injection intervals and reduced CST, PED height and retinal fluid, while maintaining BCVA at 12 months. Quantitative OCTA analysis showed reductions in MNV area and FD following the switch. When compared with the preceding 12 months of other anti-VEGF therapy, FD still showed a significant reduction after brolucizumab treatment (p = 0.019). Intraocular inflammation occurred in one eye and resolved with topical corticosteroids.
Conclusions
Intravitreal brolucizumab demonstrated favorable anatomical improvements and maintained visual outcomes over 12 months. Quantitative OCTA biomarkers, particularly FD, may serve as imaging indicators of disease activity and treatment response in eyes with nAMD undergoing a therapy switch.
4.Quantitative Analysis of Drusen in South Korean Patients: A 36-Month Follow-Up Study
Tae Rim KIM ; Tae Gi KIM ; Jaehwan CHOI ; Seung-Young YU ; Kiyoung KIM
Korean Journal of Ophthalmology 2026;40(1):87-98
Purpose:
This study aimed to quantitatively evaluate longitudinal changes in drusen area and volume over 36 months in South Korean patients and to identify the factors associated with these changes and the development of advanced age-related macular degeneration (AMD).
Methods:
In this retrospective study, 38 eyes from 38 patients diagnosed with drusen were analyzed. The drusen area and volume were measured using spectral-domain optical coherence tomography (SD-OCT; Cirrus 5000, Carl Zeiss Meditec) with an automated retinal pigment epithelium elevation map algorithm. To minimize bias from variable follow-up intervals, an annualized classification framework was adopted. Based on percentage change in drusen area within the 5-mm circle, eyes were categorized as progressed (increase >20%), stable (change within ±20%), or regressing (decrease >20%).
Results:
Both drusen area and volume increased significantly up to 24 months (area, p = 0.003; volume, p = 0.028) and then showed a modest decline at 36 months, remaining above baseline levels. No significant difference in the proportions of progressed, stable, or regressing eyes was observed across 12-month intervals or compared with baseline (all p > 0.05). A larger baseline 5-mm drusen area was significantly associated with the development of advanced AMD (adjusted odds ratio, 2.818; 95% confidence interval, 1.022–7.767; p = 0.045). Eyes that exhibited at least one episode of drusen regression showed a higher incidence of advanced AMD (36.8% vs. 5.3%, p = 0.042).
Conclusions
Drusen in South Korean patients demonstrated dynamic morphological remodeling over time. Drusen regression was not a benign phenomenon but rather a potential high-risk marker for progression to advanced AMD. These findings highlight the importance of population-specific, quantitative SD-OCT monitoring for early risk stratification in East Asian eyes.
5.Diagnostic Performance and Clinical Implications of the “Probable Hepatocellular Carcinoma” Category in the Korean Liver Cancer Association-National Cancer Center Korea Guidelines v2022
Jeong Hee YOON ; Jin-Young CHOI ; Young Kon KIM ; Chang Hee LEE ; Jeong Woo KIM ; Won CHANG ; Joon-Il CHOI ; Seung-seob KIM ; Hee Sun PARK ; Eun Sun LEE ; Jeong-Sik YU ; Seong Jin PARK ; Myung-Won YOU ; Myoung-jin JANG ; Beom Jin PARK ; Jeong Min LEE
Korean Journal of Radiology 2026;27(4):318-331
Objective:
To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines.
Materials and Methods:
This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022.
Results:
A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018.
Conclusion
The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.
6.Pilot Study for Feasibility of Onco-Geriatric Intervention Model in Older Patients with Cancer in a Tertiary Academic Hospital
Jin Won KIM ; Jung-Yeon CHOI ; Woochan PARK ; Minsu KANG ; Jeongmin SEO ; Eun Hee JUNG ; Koung Jin SUH ; Ji-Won KIM ; Se Hyun KIM ; Yu Jung KIM ; Keun-Wook LEE ; Sang-A KIM ; Ji Yun LEE ; Jeong-Ok LEE ; Soo-Mee BANG ; Kwang-il KIM ; Jee Hyun KIM
Cancer Research and Treatment 2026;58(1):329-338
Purpose:
Older cancer patients face unique challenges due to age-related physiological changes, increasing their vulnerability to treatment-related toxicities. Geriatric assessment (GA) is a validated tool for optimizing care, yet there is no consensus on integrating geriatric interventions into oncology. This study evaluates the feasibility of a tailored onco-geriatric intervention model incorporating the KG-7 screening tool.
Materials and Methods:
This prospective study included 30 patients aged ≥ 70 years with solid tumors undergoing adjuvant or palliative chemotherapy. Patients scoring ≤ 5 of KG-7 were eligible. Tailored interventions incorporating KG-7 included polypharmacy, functional status, mobility, nutrition, cognition, emotional well-being, insomnia, social support, and medical problem. KG-7, GA, and quality of life (QoL) were followed at 12 weeks.
Results:
Participants (median age, 79.5 years) had colon (43.3%), pancreatic (23.3%), or gastric cancer (23.3%). At baseline, most patients showed independent activities of daily living (100%)/instrumental activities of daily living (90%). However, 93.3% had abnormal GA. Particularly, 86.7% were either malnourished or at risk of malnutrition. The most frequently identified intervention needs included polypharmacy (70.0%), nutritional support (60.0%), and emotional well-being (50.0%) with high adherence (100.0%, 88.9%, and 46.7%, respectively). At 12 weeks, KG-7 scores improved in 43.8% of patients, and 69.2% of GA domains were improved. QoL analysis revealed modest improvement in Global Health Status (mean difference, 6.3; p=0.176). One-year survival rates were 92.3% and 79.4% for adjuvant and palliative groups, respectively.
Conclusion
The onco-geriatric intervention model incorporating KG-7 demonstrated high feasibility and potential to enhance clinical outcomes. Future studies should validate this approach in randomized trials to optimize care for older cancer patients.
7.Factors influencing the use of implantable cardioverter-defibrillators for primary prevention in ischemic cardiomyopathy according to implantation volume: a prospective multicenter registry
Tae-Hoon KIM ; Hee Tae YU ; Il-Young OH ; Eue-Keun CHOI ; Jung-Hoon SUNG ; Young Soo LEE ; Jong-Youn KIM ; Yong-Soo BAEK ; Junbeom PARK ; Boyoung JOUNG ;
International Journal of Arrhythmia 2026;27(1):e8-
Background and Objectives:
Primary prevention (PP) implantable cardioverter-defibrillator (ICD) therapy for ischemic cardiomyopathy (ICM) is underused in Asian countries, including South Korea. Both clinical and hospital factors may influence appropriate ICD use. We evaluated whether determinants of PP ICD implantation differ by hospital implantation volume.
Methods:
In this prospective, multicenter observational registry (blinded for review), patients eligible for PP ICD were enrolled. Factors associated with ICD implantation—clinical characteristics and hospital-level systems—were examined across 4 large-volume hospitals (≥ 15 implants during the study) and 12 small-volume hospitals (< 15). Multivariable logistic regression identified independent predictors.
Results:
Among 3,083 ICM patients (2,403 men; median age 70 years), PP ICD implantation rates were 10.8% in large-volume and 5.7% in small-volume hospitals. Across groups, male sex and chronic kidney disease independently predicted ICD implantation. Regarding hospital factors, non-monetary incentives for referral were the sole independent predictor in large-volume centers (odds ratio [OR], 3.55; 95% confidence interval [CI], 2.07–6.10;P < 0.001). In small-volume centers, heart failure conferences (OR, 12.73; 95% CI, 1.72–94.37;P = 0.013), structured education systems (OR, 11.72; 95% CI, 2.45–56.12; P = 0.02), and pacemaker clinics (OR, 11.4; 95% CI, 2.24–58.39; P = 0.003) were independently associated with implantation.
Conclusions
Clinical predictors of PP ICD use were consistent across hospital volumes, but hospital-level determinants differed. Referral incentives characterized large-volume centers, whereas conferences, education systems, and pacemaker clinics were key in smallvolume centers. Tailored institutional strategies by hospital volume may help close the PP ICD underuse gap and improve evidence-based implementation.
8.Establishing an Active Vaccine Safety Surveillance System Using Large Scale Databases in Korea: Lessons and Scalable Insights for Global Application
Jin Gu YOON ; Eliel NHAM ; Yu Jung CHOI ; Min Joo CHOI ; Won Suk CHOI ; Young Kyung YOON ; Yu Bin SEO ; Hakjun HYUN ; Jung Yeon HEO ; Jin-Soo LEE ; Chung-Jong KIM ; Ji Yun NOH ; Joon Young SONG ; Hee Jin CHEONG
Journal of Korean Medical Science 2026;41(1):e47-
Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.
9.Comparative survival outcomes of surgical resection versus radiotherapy after FOLFIRINOX in borderline resectable and locally advanced pancreatic cancer
Jiwon YU ; Jeong Ha LEE ; Hyunju SHIN ; Hee Chul PARK ; Joon Oh PARK ; Jung Yong HONG ; Minsuk KWON ; Ji Eun SHIN ; Kyu Taek LEE ; Kwang Hyuck LEE ; Jong Kyun LEE ; Joo Kyung PARK ; Young Hoon CHOI ; Jin Seok HEO ; In Woong HAN ; Sang Hyun SHIN ; Hongbeom KIM ; Ji Hye MIN ; Jeong Il YU
Precision and Future Medicine 2026;10(1):39-50
Purpose:
This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control.
Methods:
We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR.
Results:
Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37).
Conclusion
Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.
10.Older Adults with Diabetes in Korea: Latest Clinical and Epidemiologic Trends
Kyuho KIM ; Bongseong KIM ; Kyuna LEE ; Yu-Bae AHN ; Seung-Hyun KO ; Sung Hee CHOI ; Kyungdo HAN ; Jae-Seung YUN ;
Diabetes & Metabolism Journal 2025;49(2):183-193
Background:
Diabetes in older adults is becoming a significant public burden to South Korea. However, a comprehensive understanding of epidemiologic trends and the detailed clinical characteristics of older adults with diabetes is lacking. Therefore, we evaluated epidemiologic trends and the metabolic and lifestyle characteristics of diabetes in Korean older adults.
Methods:
We analyzed data from the Korea National Health and Nutrition Examination Survey to assess diabetes prevalence according to diabetes duration and lifestyle behaviors. In addition, we drew upon the National Health Information Database of the National Health Insurance System to assess physical activity levels, antidiabetic medication use, polypharmacy, medication adherence, and major comorbidities.
Results:
The absolute number of newly diagnosed cases of diabetes among older adults doubled over the past decade. Management rates of metabolic indicators were higher in older adults with diabetes compared to those without diabetes. The proportion of older adults with diabetes meeting the minimum recommended physical activity increased over the years. Compared to 10 years before, the use of dipeptidyl peptidase-4 inhibitor or sodium-glucose cotransporter-2 inhibitor had increased, as had comorbidities such as dyslipidemia, dementia, cancer, heart failure, atrial fibrillation, and chronic kidney disease. Initial medication adherence was significantly lower in those with end-stage kidney disease or dementia, insulin use, high-risk alcohol use, and living alone. Continuing insulin use 1 year after diagnosis of diabetes was significantly higher in those who initiated insulin therapy at diagnosis, had retinopathy, were on triple antidiabetic medications, and had a history of cancer.
Conclusion
Comprehensive management of metabolic indicators and physical activity is essential for older adults with diabetes. Improvements in prescribing guidelines, personalized management of age-related comorbidities, and individualized approaches that consider the heterogeneous nature of older adults with diabetes are desirable. Further research, such as high-quality cohort and intervention studies specific to older adults, is needed to establish evidence-based management for older adults with diabetes.

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