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.

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.

Purpose: To determine the prevalence of tamoxifen retinopathy and assess the utility of a screening protocol using non-mydriatic fundus photography and optical coherence tomography (OCT). Methods: Between May and October 2024, patients on tamoxifen therapy at a breast surgery clinic were offered screening including non-mydriatic fundus photography and OCT. Among those who consented, 290 patients (580 eyes) were included after excluding other retinal diseases. We investigated tamoxifen duration, cumulative dose, central retinal thickness, BMI, underlying diseases, menopausal status, and history of chemotherapy, hormone therapy, or oral contraceptives. Results: All patients were taking 20 mg of tamoxifen daily. The mean treatment duration was 55.7 ± 29.5 months for those treated longer than two years (n = 193), with a mean BMI of 22.1 ± 3.0 kg/m2. Systemic comorbidities included dyslipidemia (n = 27, 14.0%), hypertension (n = 19, 9.8%), diabetes mellitus (n = 13, 6.7%), and cardiovascular disease (n = 4, 2.1%). Additionally, patient histories included chemotherapy (n = 84, 43.7%), postmenopausal status (n = 56, 29.1%), hormone therapy (n = 52, 27.0%), and oral contraceptive use (n = 14, 7.2%). Tamoxifen retinopathy was not observed in any of the patients. Conclusions In this cross-sectional study, the prevalence of tamoxifen retinopathy, as assessed by non-mydriatic fundus photography and OCT in this study, was 0%, which is lower than previously reported rates (0.9%–12%). Although specialized examination by an ophthalmologist, including a dilated fundus examination and OCT remains the diagnostic gold standard, practical constraints can limit its routine clinical use. Our study evaluated a screening protocol performed without ophthalmologist intervention. However, we found that limitations in image quality compromised the detection of subtle lesions, such as crystalline deposits. Consequently, this approach may be insufficient to serve as a primary screening strategy.

Background: Postoperative liver regeneration is essential for maintaining hepatic function. This study evaluated the rate, determinants, and volumetric patterns of early liver regeneration after hemihepatectomy. Methods: A retrospective review was conducted of 50 patients who underwent right or left hemihepatectomy between April 2019 and March 2025. Liver and spleen volumes (SV) were assessed preoperatively, at postoperative day (POD) 1 week, and at POD 3 months. Early liver regeneration rate (LRR) was defined as the percentage increase in remnant liver volume at POD 1 week relative to the preoperative future liver remnant (FLR), and patients were categorized into low (<50%) and high (≥50%) LRR groups. Clinical, biochemical, and volumetric variables were compared, and predictors of regeneration were identified using multivariable analyses. Regeneration patterns were also examined according to whether the FLR/standard liver volume (SLV) ratio was <50% or ≥50%. Results: FLR/SLV was the strongest independent predictor of rapid early liver regeneration (p<0.001). Remnants with FLR/SLV <50% exhibited rapid and sustained regeneration, whereas those with FLR/SLV ≥50% showed slower regrowth that plateaued after reaching approximately 90% of SLV. SV increased at POD 1 week in all patients; however, only the FLR/SLV ≥50% group showed a reduction by POD 3 months, whereas the <50% group maintained elevated volumes. Conclusions FLR/SLV reliably predicts early postoperative liver regeneration. Smaller remnants regenerate more rapidly, whereas persistent splenic enlargement suggests a sustained portal hemodynamic burden. Combined evaluation of FLR/SLV and SV may enhance perioperative risk assessment and surgical planning.

Background: The taxonomic status of house mice (Mus musculus) on the Korean Peninsula has long been debated due to conflicting morphological classifications and limited genetic evidence. Historically, three subspecies (M. m.molossinus, M. m. utsuryonis, and M. m. yamashinai) have been proposed based on external traits, although the validity of these proposals remains uncertain. Thus, this study aimed to integrate genetic and morphological analyses to clarify the phylogenetic relationships of Korean mice relative to the well-known primary M. musculus subspecies and evaluate the taxonomic distinctiveness. Results: Genetic analysis of mitochondrial DNA (cytb gene) from mice across Korea, including islands, mountains, and agricultural fields, confirmed that these mice belong to the Eurasian M. m. musculus lineage. Morphologically, Korean mice exhibited tail ratios consistent with previously assigned subspecies, suggesting these traits represent intraspecific variation within M. m. musculus. Craniometric analyses revealed distinctive features, such as a shorter, narrower premaxillary tooth-patch width and a longer maxillary tooth-row length, thereby distinguishing these mice from laboratory strains derived from M. m. domesticus. These cranial configurations, visualized via three-dimensional micro-computed tomography scans, further supported the morphological divergence of these mice from other subspecies. Conclusions Our findings indicate that Korean house mice belong to a single subspecific group within M. m.musculus, with observed morphological variations reflecting local adaptation rather than distinct taxonomic divisions.The Korean Peninsula likely served as an ecological bridge, facilitating the spatiotemporal diversification of M. m.musculus across East Eurasia. This study resolves longstanding taxonomic ambiguities and underscores the subspecific status of Korean house mice within M. m. musculus. These insights provide a foundation for understanding the biogeographic history of human commensal species and future biomedical research utilizing wild-derived mouse models.

Background: s/Aims: The patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M variant has been implicated in metabolic dysfunction-associated steatotic liver disease (MASLD), but its role in hepatocellular carcinoma (HCC) development is unclear. This study examines the association between the PNPLA3 I148M variant and HCC occurrence. Methods: A total of 562 MASLD patients, with and without HCC, were prospectively and consecutively enrolled at two universityaffiliated hospital between June 2024 and June 2025. Genomic DNA was extracted from buccal swabs or liver biopsy samples, and single nucleotide polymorphism genotyping was performed to determine the rs738409 genotype at codon 148 of PNPLA3. The histological grade of HCC was assessed using the Edmondson-Steiner (ES) grading system in patients who underwent core-needle liver biopsy. Results: Among 474 non-HCC patients, the GG genotype was found in 39.9%, GC in 37.1%, and CC in 23.0%. In 88 HCC patients, these frequencies were 45.5%, 36.4%, and 18.2%, respectively. No significant differences in GG genotype distribution were observed between HCC and non-HCC groups (P=0.509), nor in subgroups by sex, age, obesity status, cirrhosis status, fibrosis-4 index, or liver stiffness measurement. However, among HCC patients with histological grading, the GG genotype was significantly associated with higher ES grades (P=0.0076). Conclusions The PNPLA3 I148M GG genotype was not significantly associated with increased HCC occurrence in Korean MASLD patients within the present cohort. Although the GG genotype is known to play a role in development and progression of MASLD, further studies are warranted to clarify its contribution to tumor initiation and dedifferentiation.

Background and Objectives: Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort. Methods: The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs). Results: Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective. Conclusions Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.

The brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroprotection, and we have previously demonstrated BDNF-mediated neuroprotective effects in mesenchymal stromal cells (MSCs). The present study aimed to investigate whether BDNF-overexpressing MSCs enhance the therapeutic efficacy of naïve MSCs in a preclinical model of severe neonatal intraventricular hemorrhage (IVH). We exposed primary rat neuronal cells to 40 U of thrombin overnight in vitro. Subsequently, the neuronal cells were co-cultured with either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 1 mL media) for 24 hours. Next, 300 μL of maternal blood was injected into bilateral ventricles on postnatal day (P)4 to induce severe IVH in newborn Sprague-Dawley male rats. At P6, either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 10 μL saline) were transplanted intraventricularly. Behavioral function tests, including passive avoidance, followed by endpoint analyses of brain tissue and cerebrospinal fluid were performed at P35. BDNF-overexpressing MSCs enhanced the effects of naïve MSCs against cell death, cytotoxicity, and oxidative stress in vitro. Notably, naïve and BDNF-overexpressing MSCs did not attenuate post-hemorrhagic ventricular dilatation, neuronal cell death, or gliosis. However, BDNF-overexpressing MSCs attenuated microglial activation.Furthermore, inflammatory cytokine (interleukin [IL]-1α, IL-1β, IL-6, and tumor necrosis factor-α) levels and memory function assessed using a passive avoidance test significantly improved in the BDNF-overexpressing MSC transplanted group compared with the naïve MSC transplanted group. Our data suggest that BDNF-overexpressing MSCs may offer superior protective effects to naïve MSCs in a neonatal IVH model.

Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: and Purpose: To assess the long-term effectiveness, safety, and economic viability of recently approved Alzheimer’s disease (AD) therapies, as well as to evaluate the real-world application of novel diagnostics among AD patients with diverse comorbidities, comprehensive real-world data (RWD) analysis is essential. The Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ) endeavors to create a registry of RWD derived from clinical practice on new diagnostic methods and therapeutic agents for AD introduced in Korea since 2021. Methods: Participants must fulfill all the following: 1) be at least 19 years old; 2) be actively receiving, scheduled to initiate, or undergoing evaluation for any AD disease-modifying treatment; 3) have completed amyloid positron emission tomography or cerebrospinal fluid AD immunoassay (a positive result is not essential for participation); 4) have a clinical classification of cognitively unimpaired, mild cognitive impairment, or probable AD dementia. Data generated during routine care is segmented into a minimum dataset, extended dataset, and research-only dataset requiring extra consent. Assessments encompass clinical, cognitive, functional, neurobehavioral, neuroimaging, and biomarker evaluations, in addition to systematic monitoring of new AD treatments and their safety.Data are collected and monitored at baseline, at semiannual intervals during the initial 2 years, and then annually up to 2034. To date, 46 medical centers will participate in JOY-ALZ. Conclusions JOY-ALZ is expected to promote understanding of the long-term clinical outcomes, safety, and cost-effectiveness of recently introduced diagnostics and treatments for AD, thereby supporting the progress of precision medicine in AD care and diagnosis.