1.A multi-city outbreak of Salmonella Enteritidis infections linked to bakery products, Republic of Korea
Da Seul KIM ; Soon-Young SEO ; Dong Hwi KIM ; Yeon Hee WOO ; Deborah LEE ; Se Jeong YANG ; Junyoung KIM ; Eunkyung SHIN ; Byungsun JUNG ; Eunmi LEE ; Min Jung LEE ; Young-Joon PARK
Osong Public Health and Research Perspectives 2026;17(1):61-71
Objectives:
In May 2025, clusters of salmonellosis were identified in 7 cities in the Republic of Korea, all associated with consumption of identical bakery products. This investigation aimed to characterize the outbreak, identify potential contributing factors, and inform strategies for preventing similar multi-facility foodborne outbreaks.
Methods:
A case series study was conducted among individuals who consumed Manufacturer H’s Product I and Product II on May 15–16, 2025 at 7 facilities (n = 1,235). Clinical specimens from symptomatic individuals, retained food samples, and environmental samples were collected and tested. Food-exposure histories were assessed, and active case finding was implemented across all supplied facilities. Traceback investigations were conducted at the manufacturer, distributor, and egg farms. Human and food isolates underwent pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS).
Results:
A total of 323 cases met the outbreak case definition (attack rate, 26.2%), of which 48 were laboratory-confirmed. Salmonella Enteritidis was isolated from both clinical specimens and retained bakery products. PFGE patterns were indistinguishable between human and food isolates, and WGS demonstrated high genetic relatedness. These findings confirmed a common-source outbreak linked to the implicated bakery products.
Conclusion
This outbreak underscores the value of integrating epidemiological investigation, active case finding, and molecular typing to identify common food vehicles in outbreaks involving widely distributed manufactured foods. Coordinated collaboration between public health and food safety authorities is essential for the effective detection, response, and prevention of multi-facility foodborne outbreaks.
2.Injury patterns and characteristics in pediatric emergency department visits in Korea: focusing on self-harm, suicide, violence, and assault
Miyeon YANG ; Eunhwa PARK ; Jiyeon KIM ; Donghyun NAM ; Myounghwa LEE
Pediatric Emergency Medicine Journal 2026;13(1):9-18
Purpose:
This study analyzed the characteristics of pediatric patients’ (≤ 18 years) intentional injury-related visits to the emergency department (ED) using National Emergency Department Information System data from January 1 through December 31, 2023, providing foundational evidence for prevention strategies and policy development.
Methods:
The injuries were categorized into unintentional and intentional, and relevant characteristics were compared between the 2 categories. The intentional injuries were further divided into self-harm and violence. Percentages were calculated for each variable and compared using the chi-square or Fisher exact tests.
Results:
Among 301,852 pediatric patients, those with intentional injuries showed higher proportions of girls, adolescents, visits in the wee hours, visits via firehouse ambulances, injuries by collision, by penetration, or by poisoning, hospitalization, Korean Triage and Acuity Scale levels 1-3, an ED length of stay of 2 hours or longer, and primary care by psychiatrists, than those with unintentional injuries. The pediatric patients with self-harm injuries showed higher proportions of girls, adolescents, visits in the wee or morning hours, visits via firehouse ambulances, injuries by collision, by penetration, or by poisoning, hospitalization or inter-facility transfer, Korean Triage and Acuity Scale levels 1-3, an ED length of stay of 2 hours or longer, and primary care by psychiatrists as well as by orthopedic surgeons or pediatricians, than those with violence injuries.
Conclusion
This study highlights the need to develop strategies per age and sex for preventing self-harm among pediatric patients, and to ensure safe and effective psychiatric care in EDs. In addition, the prevention of child abuse requires a multidisciplinary approach that includes preventive education programs, mandatory reporting in EDs, and the adoption of screening tools such as the Finding Instrument for Non-accidental Deeds.
3.Arteriovenous fistulas are associated with superior outcomes in very elderly hemodialysis patients: a nationwide cohort study
Hyung Duk KIM ; Do Hyoung KIM ; Hyangkyoung KIM ; Hyung-Seok LEE ; Seung Boo YANG ; Seok Joon SHIN ; Hoon Suk PARK ;
The Korean Journal of Internal Medicine 2026;41(1):152-162
Background/Aims:
The optimal vascular access strategy for very elderly patients initiating hemodialysis (HD) remains unclear. Arteriovenous fistulas (AVFs) offer long-term benefits but may be limited due to vascular aging. This study evaluated vascular access outcomes in patients aged ≥ 80 years.
Methods:
We conducted a retrospective cohort study using data from the Korean National Health Insurance Service between 2008 and 2019. Patients aged ≥ 80 years who initiated HD with a newly created AVF or arteriovenous graft (AVG) were included. Primary outcomes were primary, assisted primary, and secondary patency. The secondary outcome was all-cause mortality. Outcomes were compared using Kaplan–Meier analysis and multivariable Cox regression.
Results:
Among 8,487 patients, 5,124 (60.4%) received AVFs (AVF group) and 3,363 (39.6%) received AVGs (AVG group). AVFs were associated with significantly lower rates of patency loss across all definitions. The adjusted hazard ratios (HRs) for AVG vs. AVF were 1.76 (95% confidence interval [CI], 1.67–1.86) for primary patency loss, 1.90 (95% CI, 1.77–2.03) for assisted primary, and 3.18 (95% CI, 2.81–3.61) for secondary patency loss. All-cause mortality was also higher in the AVG group (adjusted HR, 1.24; 95% CI, 1.17–1.30).
Conclusions
In this large-scale study, AVF use was associated with superior patency and lower mortality compared with AVG in patients aged ≥ 80 years. These findings suggest that AVF remains a beneficial option for appropriately selected elderly patients and that age alone should not be a primary barrier to its creation.
4.Comparative efficacy and safety of warfarin and direct oral anticoagulants in patients with end-stage kidney disease and atrial fibrillation
Yujin YANG ; Sun Hwa LEE ; Wonmook HWANG ; Ji Hoon JUNG ; Jae-Hyeong PARK
The Korean Journal of Internal Medicine 2026;41(1):107-117
Background/Aims:
Patients with atrial fibrillation (AF) and end-stage kidney disease (ESKD) require careful anticoagulation because thrombotic and bleeding risks are both elevated. We evaluated the efficacy and safety of warfarin, direct oral anticoagulants (DOACs), and no anticoagulation in Korean patients with ESKD and AF.
Methods:
In this multicenter retrospective study, we included 933 patients with ESKD and nonvalvular AF treated between 2010 and 2023. Patients were assigned to three groups by initial treatment: no anticoagulation (n = 604), warfarin (n = 197), or DOACs (n = 132). The primary efficacy outcome was ischemic stroke or systemic embolism (IS/SE); the primary safety outcome was major bleeding (MB). Secondary outcomes were intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), and all-cause mortality. Inverse probability of treatment weighting was used to adjust for confounding.
Results:
Both warfarin (adjusted hazard ratio [aHR], 0.55) and DOACs (aHR, 0.36) significantly reduced the risk of IS/SE compared with no anticoagulation. However, warfarin increased MB risk compared with no anticoagulation (aHR, 2.69), including ICH and GIB. DOACs also increased MB risk versus no anticoagulation (aHR, 1.37), driven primarily by ICH. Compared with warfarin, DOACs showed a lower MB risk (aHR, 0.51). Both warfarin and DOACs reduced all-cause mortality relative to no anticoagulation (aHR, 0.53 and 0.57, respectively).
Conclusions
Among Korean patients with ESKD and AF, both warfarin and DOACs reduced IS/SE but increased MB. Given their lower MB risk than warfarin, DOACs may be preferable for anticoagulation in this high-risk population.
5.Efficacy and Safety of Novel Botulinum Toxin Type A (Protoxin) in the Treatment of Moderate to Severe Glabellar Lines: A Multicenter, Randomized, Double-Blind, Active-Controlled Phase III Study
Hyung Seok SON ; Min Kyung SHIN ; Jong Hun LEE ; Moon Bum KIM ; Kwang Ho YOO ; Sun Young CHOI ; Hye Sung HAN ; Joon SEOK ; Beom Joon KIM ; Yang Won LEE
Annals of Dermatology 2026;38(1):33-41
Background:
A novel botulinum toxin type A (Protoxin; Protox Inc.) has been developed.
Objective:
To evaluate the efficacy and safety of the newly developed Protoxin compared to the approved drug onabotulinumtoxinA (OBoNT) in moderate to severe glabellar lines.
Methods:
Adults with a glabellar line Facial Wrinkle Scale (FWS) score of 2 (moderate) or 3 (severe) were enrolled in the study. Subjects were randomized in a 1:1 ratio to receive either Protoxin or OBoNT. A total of 20 units of botulinum toxin was injected at five sites in the glabellar region (4 units at each site). FWS scores were assessed at baseline and at weeks 4, 8, 12, and 16 post-injection. The primary endpoint was the proportion of subjects at week 4 who had a reduction of 2 or more points in FWS and a final score of 0 (none) or 1 (mild).
Results:
A total of 274 subjects were randomized, of whom 78.1% were female. At week 4 post-treatment, the improvement rate of glabellar lines was 62.22% in the Protoxin group and 62.96% in the OBoNT group. The lower limit of the two-sided 95% confidence interval (−12.24%) exceeded the −15% margin, confirming the non-inferiority of the new drug. Safety profiles were comparable between the two groups.
Conclusion
Protoxin demonstrated efficacy and safety profiles comparable to those of OBoNT in the treatment of moderate to severe glabellar lines.
6.Development and Validation of a Lectin-independent Liquid Chromatography–Tandem Mass Spectrometry Method for Serum Glycosylated Alpha-fetoprotein Analysis and Comparison with a Liquid-phase Binding Assay
Hyojin KIM ; Juri PARK ; Hanseul SUH ; Saeyoung LEE ; Yoonha PARK ; Won Suk YANG ; Dohsik MINN ; Soon Sun KIM ; Jae Youn CHEONG ; Je-Hyun BAEK
Annals of Laboratory Medicine 2026;46(1):62-71
Background:
Alpha-fetoprotein (AFP) and its isoform AFP-L3 are well-established serum biomarkers for hepatocellular carcinoma (HCC), a common malignancy and a leading cause of cancer-related mortality worldwide. Current methods for measuring these biomarkers are primarily lectin-based assays including the liquid-phase binding assay (LiBA) and liquid chromatography–tandem mass spectrometry (LC-MS/MS), both of which have limitations in diagnostic sensitivity and clinical utility for samples with low AFP concentrations. We aimed to develop a lectin-independent LC-MS/MS method for quantifying fucosylated AFP proteins (AFP-Fuc%).
Methods:
We conducted analytical validation, including method comparisons, over 2 months. The analytical sensitivity and diagnostic performance of this method were evaluated using 525 human serum samples—235 from HCC patients and 290 from non-HCC individuals—and compared with those of LiBA, which measured AFP-L3 levels.
Results:
The LC-MS/MS method demonstrated acceptable within-laboratory imprecision (CVs < 17.1%) without detectable bias, carryover, or matrix effects. Our method exhibited a broader linear dynamic range (spanning five orders of magnitude) and 10-fold higher analytical sensitivity than LiBA. The diagnostic performance of our method was significantly superior to that of LiBA, particularly in patients with low AFP concentrations ( < 7 ng/mL, P < 0.001), with improved accuracy, sensitivity, and precision at a specificity of 96.2%.
Conclusions
The validated LC-MS/MS method demonstrated robust analytical performance and superior diagnostic accuracy over LiBA for HCC diagnosis while avoiding the inherent limitations of lectin-based assays. Our LC-MS/MS assay shows promise for early HCC detection and may contribute to enhanced patient care.
7.Paradigm Shift in Monoclonal Protein Detection: From Electrophoresis-based to Mass Spectrometry–based Methods
Jikyo LEE ; Sangmi YOO ; Seojin YANG ; Sang Hoon SONG
Annals of Laboratory Medicine 2026;46(1):3-15
Monoclonal protein (M-protein) is a crucial biomarker for diagnosing and monitoring monoclonal gammopathies, including multiple myeloma (MM). Traditionally, electrophoresis (EP)-based methods, such as protein EP and immunofixation EP, have been widely used for M-protein detection. However, these methods can show low sensitivity and inadequate quantification of small amounts of M-protein. To overcome these challenges, EP-based methods are often combined with the quantification of serum free light chains in automated immunoassays. Advances in mass spectrometry (MS) have introduced three main approaches for sample preparation: top-down, middle-down, and bottom-up. Middle-down approaches are commonly used with matrix-assisted laser desorption/ionization time-offlight MS and liquid chromatography–electrospray ionization (LC–ESI) quadrupole time-offlight MS, whereas the bottom-up approach is typically applied with LC–ESI Orbitrap MS. A review of studies, conducted from 2014 to 2024, on plasma cell disorders that utilized MS-based methods demonstrate improvements in the sensitivity and accuracy of M-protein identification and quantification. MM remains the most frequently studied disease, with significant therapeutic advancements leading to improved outcomes. Minimal residual disease has gained attention because of its correlation with better prognoses. Monoclonal gammopathy of undetermined significance and amyloid light-chain amyloidosis are occasionally addressed, while studies on other rare diseases remain limited. This review highlights the clinical applications and advancements in MS-based methods, particularly in assessing M-protein levels for treatment responses, risk factors, and prognostic monitoring. Given their advantages—high sensitivity and specificity, automation, cost-effectiveness, and time efficiency—MS-based methods may eventually replace EP-based methods in clinical laboratories.
8.Association between initial mental health status and glycemic control in pediatric diabetes
Jeongho HAN ; Mi YANG ; Hakyung LEE ; Dong Jun HA ; Hwa Young KIM ; Hee Jeong YOO ; Jae Hyun HAN ; Jaehyun KIM
Annals of Pediatric Endocrinology & Metabolism 2026;31(2):101-109
Purpose:
Psychiatric conditions are common in children and adolescents with diabetes and can hinder disease management. In this study, we examined whether mental health status at diagnosis predicts glycemic control at 1 year.
Methods:
We included 57 patients aged 6–18 years diagnosed with type 1 or type 2 diabetes between 2019 and 2023 at Seoul National University Bundang Hospital. Mental health was assessed within 3 months of diagnosis using the Eating Disorder Inventory-2, Children’s Depression Inventory, and Child Behavior Checklist (CBCL) for ages 6–18. Poor glycemic control was defined as glycated hemoglobin >6.5% at 1 year. Associations between screening results and glycemic control were analyzed using Fisher exact test and multivariate logistic regression.
Results:
Of the 57 patients, 32 (56.1%) had type 1 diabetes, and the mean age at diagnosis was 12.9±3.1 years; 31 (54.4%) were male. Poor glycemic control at 1 year was observed in 16 patients (28.1%). Although individual subscale positivity was not significantly associated with glycemic control, borderline somatic complaints on the CBCL were significantly associated with poor control (p=0.022). In multivariate analysis, having 2 or more positive CBCL subscales showed a trend toward association with poor glycemic control (adjusted odds ratio=21.47, p=0.054).
Conclusion
Early psychological screening, especially for somatic symptoms or multiple psychological problems, may help identify those at risk for poor glycemic control in pediatric diabetes. These findings underscore the importance of early detection and intervention in optimizing diabetes management.
9.Eccentric Cycling Improves Cardiopulmonary Fitness, Respiratory Function, and Quality of Life in Chronic Kidney Disease: A Randomized Controlled Trial
Yu-Ting HUANG ; Hsin-Yeh LEE ; Hui-Ching CHENG ; Hsin-Lun YANG ; Ching-Hsia HUNG ; Chien-Chou SU ; Yu-Tzu CHANG ; Chien-Yao SUN ; Kun-Ling TSAI
Annals of Rehabilitation Medicine 2026;50(2):105-116
Objective:
To compare the effects of eccentric cycling (ECC), concentric cycling (CON), and standard care (CTL) on cardiopulmonary capacity, respiratory health, and quality of life (QoL) in patients with chronic kidney disease (CKD).
Methods:
Thirty-one CKD patients were divided into the CTL, CON, and ECC groups. The CON and ECC groups participated in 8-week, 24-session cycling programs. Outcomes were assessed through cardiopulmonary exercise tests, respiratory function tests, and the 36-Item Short Form Survey Instrument questionnaire.
Results:
The ECC group achieved significant improvements in maximal oxygen uptake, while the CTL group showed a decline. For oxygen uptake efficiency slope, significant changes were observed only in the ECC group, with a group-by-time interaction effect compared to CTL. Furthermore, the ECC group demonstrated the most significant increase in diaphragm movement and a significant increase in diaphragm thickness, with comparisons indicating that ECC outperformed both CTL and CON. Regarding QoL, the ECC group exhibited significantly greater improvements in Physical Component Summary and Mental Component Summary, with statistically significant differences compared with the CTL and CON groups.
Conclusion
ECC is a low-effort, high-benefit exercise modality that significantly enhances cardiopulmonary fitness, respiratory function, and QoL in patients with CKD.
10.Nationwide Survey on Endoscopic Submucosal Dissection for Early Gastric Cancer in Korea: Results From the Korean College of Helicobacter and Upper Gastrointestinal Research (KCHUGR) 2023 Survey
Jae Yong PARK ; Jeong Hoon LEE ; Tae-Se KIM ; Da Hyun JUNG ; Bong Eun LEE ; Yonghoon CHOI ; Wan-Sik LEE ; Young-Il KIM ; Sun Hyung KANG ; Hyunsoo CHUNG ; Su Jin KIM ; Joon Sung KIM ; Donghoon KANG ; Su Youn NAM ; Seung Han KIM ; Hyo-Joon YANG ; Hyun LIM ; Jin LEE ; Seon-Young PARK ; Seung-Woo LEE ; Sun Moon KIM ; Sam Ryong JEE ; Dae Young CHEUNG ; Chung Hyun TAE ; Seokin KANG ; Sung Chul PARK ; Seung In SEO ; Cheol Min SHIN ; Kee Don CHOI ; Jong Yeul LEE ;
Journal of Gastric Cancer 2026;26(2):169-183
Purpose:
Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research.
Materials and Methods:
Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes.
Results:
Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days.
Conclusions
This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

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