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.Eradication of Aspiculuris tetraptera in various immunodeficient mouse models using ivermectin: a case report
Ji-Hun LEE ; Eun-Seon YOO ; Na-Won KIM ; Han-Bi JEONG ; Ah-Reum KANG ; Sun-Min SEO ; Young-Jun PARK ; Byeong-Cheol KANG ; Yang-Kyu CHOI
Laboratory Animal Research 2026;42(1):82-87
Background:
Despite advancements in laboratory animal facility management, pinworm infections remain a persistent issue in immunodeficient mouse colonies. Rapid diagnosis and treatment are crucial to mitigating potential scientific and economic consequences. Effective control requires both the administration of anthelmintic agents and rigorous environmental decontamination. However, the safety and efficacy of these treatments in genetically modified mouse models remains uncertain.Case presentation Aspiculuris tetraptera infestation was identified in multiple immunodeficient mouse models housed in a laboratory facility. Diagnosis was confirmed through fecal flotation for egg detection and necropsy for adult worm examination in the large intestines. Mice received three subcutaneous ivermectin injections at two-week intervals, coupled with environmental decontamination using ivermectin spray for four consecutive weeks. Following treatment, all colonies tested negative for A. tetraptera without any mortality.
Conclusions
A combination of subcutaneous ivermectin injection and environmental spray application effectively eradicated A. tetraptera infestation in immunodeficient mouse colonies. The treatment protocol led to the complete elimination of eggs and adult worms, offering a practical strategy for managing pinworm infections in genetically modified mouse models. Limitations include the small sample size, and the lack of a comprehensive evaluation of physiological and metabolic safety in immunodeficient mice. Further validation will be required to confirm the broader applicability of this approach.
3.Combination Therapy with Betulinic Acid and TRAIL Increases ROS-Dependent Cytotoxicity and Inhibits PI3K/Akt Signaling in Human Bladder Cancer Cells
Cheol PARK ; Hee-Jae CHA ; Su Hyun HONG ; Heui-Soo KIM ; Sun-Hee LEEM ; Jung-Hyun SHIM ; Gi-Young KIM ; Kyoung Ah KANG ; Jin Won HYUN ; Yung Hyun CHOI
Biomolecules & Therapeutics 2026;34(3):641-651
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine that selectively targets cancer cells and induces apoptosis. However, many cancers, including bladder cancer, develop resistance to TRAIL, limiting the efficacy of TRAIL-based therapies. This study investigated whether betulinic acid (BA), a pentacyclic triterpenoid with anticancer and chemosensitizing properties, increases TRAIL-mediated apoptosis in TRAIL-resistant human bladder cancer cells. Combination treatment with BA and TRAIL significantly increased cytotoxicity and apoptosis compared to either treatment alone. This combination treatment also increased reactive oxygen species (ROS) production, increased Bax expression and Bid cleavage (tBid formation), and downregulated Bcl-2 levels. These effects were accompanied by caspase activation via extrinsic and intrinsic pathways, leading to cytochrome c release via mitochondrial membrane destabilization, thereby contributing to increased apoptosis. Furthermore, the combination treatment inhibited phosphoinositide 3-kinase (PI3K) and Akt phosphorylation; this effect was amplified by a PI3K inhibitor but abrogated by ROS inhibition. Collectively, our results suggest that BA sensitizes bladder cancer cells to TRAILinduced apoptosis via ROS-dependent activation of the apoptotic pathway and inhibition of PI3K/Akt signaling. Therefore, the BA and TRAIL combination exhibits potential to overcome TRAIL resistance in human bladder cancer.
4.Radiation-Induced Cavernous Malformation in the Cerebellum:Clinical Features of Two Cases
Hyoung Soo CHOI ; Chae-Yong KIM ; Byung Se CHOI ; Seung Hyuck JEON ; In Ah KIM ; Joo-Young KIM ; Kyu Sang LEE ; Gheeyoung CHOE
Brain Tumor Research and Treatment 2025;13(2):58-64
Radiation-induced cavernous malformations (RICMs) are rare but significant late complications of highdose radiation therapy, particularly in young survivors of brain tumors. This report presents two cases of RICMs following aggressive multimodal treatment, including surgery, chemotherapy, and radiation therapy. Case 1 was a 22-year-old male patient with medulloblastoma treated with craniospinal irradiation, tumor bed boost, and tandem autologous peripheral blood stem cell transplantation. Approximately 8 years after treatment completion, routine follow-up imaging revealed a small focal hemorrhage in the right cerebellum, consistent with an RICM. The lesion was asymptomatic and managed conservatively with regular imaging, showing spontaneous resolution over time, with a significant size reduction noted 9 years post-treatment. Case 2 describes a 32-year-old male with an intracranial germinoma treated with whole-ventricular irradiation. Three years after treatment, the patient developed a symptomatic hemorrhagic RICM near a pre-existing developmental venous anomaly. Surgical resection and Gamma Knife Surgery stabilized the lesion; however, residual symptoms, including tremors and gait disturbances, persisted, affecting the patient’s daily activities. These cases illustrate the diverse clinical courses of RICMs, ranging from spontaneous resolution to the necessity of surgical intervention, and emphasize the importance of long-term surveillance and tailored management strategies for late-onset complications.
5.Target-Enhanced Whole-Genome Sequencing Shows Clinical Validity Equivalent to Commercially Available Targeted Oncology Panel
Sangmoon LEE ; Jin ROH ; Jun Sung PARK ; Islam Oguz TUNCAY ; Wonchul LEE ; Jung-Ah KIM ; Brian Baek-Lok OH ; Jong-Yeon SHIN ; Jeong Seok LEE ; Young Seok JU ; Ryul KIM ; Seongyeol PARK ; Jaemo KOO ; Hansol PARK ; Joonoh LIM ; Erin CONNOLLY-STRONG ; Tae-Hwan KIM ; Yong Won CHOI ; Mi Sun AHN ; Hyun Woo LEE ; Seokhwi KIM ; Jang-Hee KIM ; Minsuk KWON
Cancer Research and Treatment 2025;57(2):350-361
Purpose:
Cancer poses a significant global health challenge, demanding precise genomic testing for individualized treatment strategies. Targeted-panel sequencing (TPS) has improved personalized oncology but often lacks comprehensive coverage of crucial cancer alterations. Whole-genome sequencing (WGS) addresses this gap, offering extensive genomic testing. This study demonstrates the medical potential of WGS.
Materials and Methods:
This study evaluates target-enhanced WGS (TE-WGS), a clinical-grade WGS method sequencing both cancer and matched normal tissues. Forty-nine patients with various solid cancer types underwent both TE-WGS and TruSight Oncology 500 (TSO500), one of the mainstream TPS approaches.
Results:
TE-WGS detected all variants reported by TSO500 (100%, 498/498). A high correlation in variant allele fractions was observed between TE-WGS and TSO500 (r=0.978). Notably, 223 variants (44.8%) within the common set were discerned exclusively by TE-WGS in peripheral blood, suggesting their germline origin. Conversely, the remaining subset of 275 variants (55.2%) were not detected in peripheral blood using the TE-WGS, signifying them as bona fide somatic variants. Further, TE-WGS provided accurate copy number profiles, fusion genes, microsatellite instability, and homologous recombination deficiency scores, which were essential for clinical decision-making.
Conclusion
TE-WGS is a comprehensive approach in personalized oncology, matching TSO500’s key biomarker detection capabilities. It uniquely identifies germline variants and genomic instability markers, offering additional clinical actions. Its adaptability and cost-effectiveness underscore its clinical utility, making TE-WGS a valuable tool in personalized cancer treatment.
6.Application of Machine Learning Algorithms for Risk Stratification and Efficacy Evaluation in Cervical Cancer Screening among the ASCUS/LSIL Population: Evidence from the Korean HPV Cohort Study
Heekyoung SONG ; Hong Yeon LEE ; Shin Ah OH ; Jaehyun SEONG ; Soo Young HUR ; Youn Jin CHOI
Cancer Research and Treatment 2025;57(2):547-557
Purpose:
We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL).
Materials and Methods:
Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates.
Results:
Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination.
Conclusion
In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.
7.The Cancer Clinical Library Database (CCLD) from the Korea-Clinical Data Utilization Network for Research Excellence (K-CURE) Project
Sangwon LEE ; Yeon Ho CHOI ; Hak Min KIM ; Min Ah HONG ; Phillip PARK ; In Hae KWAK ; Ye Ji KANG ; Kui Son CHOI ; Hyun-Joo KONG ; Hyosung CHA ; Hyun-Jin KIM ; Kwang Sun RYU ; Young Sang JEON ; Hwanhee KIM ; Jip Min JUNG ; Jeong-Soo IM ; Heejung CHAE
Cancer Research and Treatment 2025;57(1):19-27
The common data model (CDM) has found widespread application in healthcare studies, but its utilization in cancer research has been limited. This article describes the development and implementation strategy for Cancer Clinical Library Databases (CCLDs), which are standardized cancer-specific databases established under the Korea-Clinical Data Utilization Network for Research Excellence (K-CURE) project by the Korean Ministry of Health and Welfare. Fifteen leading hospitals and fourteen academic associations in Korea are engaged in constructing CCLDs for 10 primary cancer types. For each cancer type-specific CCLD, cancer data experts determine key clinical data items essential for cancer research, standardize these items across cancer types, and create a standardized schema. Comprehensive clinical records covering diagnosis, treatment, and outcomes, with annual updates, are collected for each cancer patient in the target population, and quality control is based on six-sigma standards. To protect patient privacy, CCLDs follow stringent data security guidelines by pseudonymizing personal identification information and operating within a closed analysis environment. Researchers can apply for access to CCLD data through the K-CURE portal, which is subject to Institutional Review Board and Data Review Board approval. The CCLD is considered a pioneering standardized cancer-specific database, significantly representing Korea’s cancer data. It is expected to overcome limitations of previous CDMs and provide a valuable resource for multicenter cancer research in Korea.
8.The comparative study of Stretta radiofrequency and anti-reflux mucosectomy in the management of intractable gastroesophageal reflux disease: a single-center retrospective study from Korea
Ah Young LEE ; Ji Woo CHOI ; Jeong Haeng HEO ; Jun Young CHUNG ; Seong Hwan KIM ; Joo Young CHO
Clinical Endoscopy 2025;58(3):409-417
Background/Aims:
Chronic gastroesophageal reflux disease (GERD) requires symptom relief and treatment of associated conditions. In this study, we aimed to compare anti-reflux mucosectomy (ARMS) and Stretta radiofrequency (SRF) for treating patients with chronic GERD who are unresponsive to proton pump inhibitors (PPIs) and to identify the indications for each procedure.
Methods:
Data of patients who underwent ARMS or SRF between March 2021 and April 2023 were analyzed. Changes in GERD questionnaire (GERDQ) scores, endoscopic Los Angeles (LA) grade, flap valve grade (FVG) based on Hill’s type, EndoFLIP distensibility index (DI), endoscopic Barrett’s epithelium (BE) resolution rate, and PPI withdrawal rate were compared between the two groups.
Results:
Improvements in the GERDQ scores and PPI withdrawal rates were similar between the groups. The ARMS group showed significantly better changes in endoscopic LA grade, FVG, and EndoFLIP DI than the SRF group. The complications were more prevalent in the ARMS group than in the SRF group.
Conclusions
The change in endoscopic LA grade before and after the procedure was significantly higher in the ARMS group than in the SRF group. Significant improvements in endoscopic FVG, BE resolution, and EndoFLIP DI were observed only with the ARMS group.
9.Profiling of Anti-Signal-Recognition Particle Antibodies and Clinical Characteristics in South Korean Patients With Immune-Mediated Necrotizing Myopathy
Soo-Hyun KIM ; Yunjung CHOI ; Eun Kyoung OH ; Ichizo NISHINO ; Shigeaki SUZUKI ; Bum Chun SUH ; Ha Young SHIN ; Seung Woo KIM ; Byeol-A YOON ; Seong-il OH ; Yoo Hwan KIM ; Hyunjin KIM ; Young-Min LIM ; Seol-Hee BAEK ; Je-Young SHIN ; Hung Youl SEOK ; Seung-Ah LEE ; Young-Chul CHOI ; Hyung Jun PARK
Journal of Clinical Neurology 2025;21(1):31-39
Background:
and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM).
Methods:
We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined.
Results:
The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies.
Conclusions
This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.
10.Patterns of Medical Utilization in Children, Adolescents, and Young Adults With Life-Limiting Conditions in Korea: A Cohort Study Based on National Health Insurance Data
Seonhwa LEE ; Byungmi KIM ; Jin Young CHOI ; So-Jung PARK ; Jun Ah LEE ; Chung Ho KIM ; Bomi PARK ; Bohyun PARK
Journal of Korean Medical Science 2025;40(7):e27-
Background:
Children, adolescents, and young adults (CAYAs) with severe illnesses require intensive treatment, often relying on medical devices and advanced medical services.Modern medical technology has improved the lifespans of these patients. In addition, CAYAs represent a vulnerable group, resulting in a significant caregiving burden on the entire family.This study examined patterns of medical utilization following diagnosis of a life-limiting condition (LLC).
Methods:
We establish a cohort of 176,236 CAYAs who were first diagnosed with an LLC using National Health Insurance data between 2011 and 2013. Patients diagnosed with an LLC within the 3 years preceding this period and those who had died were excluded, and only those receiving care at a general medical hospital were included. In total, 25,410,411 claims for medical expenses, outpatient visits, and lengths of stay for medical utilization over the approximately 10 years up to 2020 were investigated (2.3% inpatients, 97.7% outpatients).
Results:
The average annual medical utilization per LLC patient among CAYAs following initial diagnosis included medical expenses of $1,163, 16.8 outpatient visits, and 18.7 days of admission. Among inpatients, cancer patients averaged $5,340 for total medical expenses and 21.0 days of admission, while non-cancer patients averaged $3,013 and 18.1 days, respectively. The overall average medical expenses during the first year following diagnosis of an LLC were $3,012, whereas for cancer patients they were $5,962. In addition, there was a sharp increase in total medical expenses as death approached, particularly in the last month of life, with a considerable proportion attributable to critical-care treatments.
Conclusion
Our investigation into medical utilization by CAYAs with an LLC in Korea provides a foundation for healthcare policy development. Timely treatment at each stage and tailored policies that take into account the heterogeneity among diseases are of paramount importance.

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