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.

Immunosenescence, an age-associated decline in immune function, is increasingly recognized as a central determinant of health and disease in older adults. Characterized by thymic involution, loss of naïve T cells, contraction of T cell receptor diversity, accumulation of senescent and exhausted lymphocytes, and a chronic inflammatory state known as inflammaging, immunosenescence compromises both innate and adaptive immune responses. Immunosenescence contributes to the pathogenesis of diverse age-related diseases. In autoimmune and metabolic diseases, premature accumulation of senescent T cells and impaired regulatory T cell function drive chronic inflammation and tissue damage, while in neurodegenerative diseases, microglial aging and sustained neuroinflammation exacerbate neuronal loss. These findings highlight immunosenescence as a unifying mechanism linking aging to systemic and organ-specific pathologies. Advances in biomarker discovery, including phenotypic markers, telomere attrition, and epigenetic signatures, have enabled the quantitative assessment of immune aging, while emerging therapeutic strategies, such as cytokine modulation, mTOR inhibition, senolytics, and epigenetic reprogramming, show promise in restoring immune competence. Here, we summarize recent research on immunosenescence in various diseases, particularly chronic inflammatory, metabolic, and neurodegenerative diseases, and suggest novel strategies for the development of senolytic drugs.

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.

Olanzapine is a second-generation antipsychotic drug associated with the development of type 2 diabetes. However, the development and remission of diabetes with glutamic acid decarboxylase (GAD) antibody (Ab) positivity related to olanzapine treatment have not been reported. Here, we present the case of a 33-year-old man taking olanzapine who was diagnosed with diabetes with GAD Ab positivity complicated by diabetic ketoacidosis (DKA). After discontinuation of the drug and tight glycemic control, his diabetes remitted, and the GAD Ab became negative spontaneously after 18 months. The classification of diabetes is challenging because of overlapping autoimmune and metabolic features. Olanzapine may have contributed to pancreatic β-cell apoptosis, which could potentially trigger autoimmunity and the development of type 1 diabetes-like features (DKA as the initial presentation, a low C-peptide level, and GAD Ab positivity). The rapid amelioration of hyperglycemia and weight reduction may be responsible for the remission of diabetes after the discontinuation of olanzapine.

Background: The Korean Occupational Stress Scale (KOSS) was developed in 2004. During this time, industrial structures have evolved, and societal awareness of occupational stress has changed. This study aims to develop and validate a revised version of the Korean Occupational Stress Scale (KOSS®19), tailored for workers, reflecting these changes. Methods: The KOSS®19 was developed based on the 26-item KOSS–short form (SF) through a review by eight experts. A survey was conducted including 359 service industry workers, comprising the KOSS®19, Burnout, and Depression scales. The KOSS®19 subscales were restructured, and their reliability and validity were evaluated. Results: The KOSS®19 composed of eight subscales: hazardous physical environment (2 items), high job demand (3 items), insufficient job control (2 items), low social support (2 items), job insecurity (2 items), organizational injustice (4 items), lack of reward (2 items), and work-life imbalance (2 items). The reliability and validity of the KOSS®19 were found to be satisfactory. Conclusions The KOSS®19 is a suitable tool for assessing occupational stress, effectively replacing the original KOSS and KOSS-SF.

Background: Emotional labor refers to the management of emotions and expressions to meet the emotional requirements of a job role. This study aimed to develop a revised version of the Korean Emotional Labor Scale (KELS®11), based on the first edition (KELS-24) introduced in 2014, and to provide practical applications and guidelines for its use in the Korean workplace through a validation process. Methods: The revised version of KELS®11 was derived from the 24-item KELS, following a review process involving eight experts. To validate the scale’s reliability and validity, a self-administered survey was conducted among 359 service industry workers using KELS®11, burnout, and depression scales. KELS®11 was reclassified, and its reliability and validity were evaluated. Receiver operating characteristic curve analysis was conducted to establish sex-specific cutoff values (normal vs. high-risk groups). Results: KELS®11 was designed to account for individual, organizational, and cultural contexts. It consists of four subscales and 11 items: “emotional regulation” (2 items), “emotional dissonance” (3 items), “organizational monitoring” (2 items), and “organizational protective system for emotional labor” (4 items). KELS®11 demonstrated good validity (content validity ratio: 0.84; item convergence/discriminant validity success rates: 100%; correlation with burnout: r = 0.185–0.436, p < 0.01; correlation with depression: r = 0.128–0.339, p < 0.05) and reliability (Cronbach’s alpha: 0.597–0.795). Additionally, sex-specific reference values were established to determine risk groups based on the intensity of emotional labor exposure. Conclusions KELS®11 is a validated and reliable measurement tool designed to assess the intensity and magnitude of emotional labor in the workplace. The revised tool reflects critical considerations in the development of emotional labor measurement scales.

Background: Workplace violence refers to any act or threat of physical violence, verbal abuse, harassment, intimidation, bullying, mobbing, or other aggressive and disruptive behaviors that occur at work. This study aims to develop and validate a revision of the Korean Workplace Violence Scale (KWVS®13), based on the first edition of the Korean Workplace Violence Scale (KWVS-24), and to provide practical applications and guidelines for the Korean workplace environment. Methods: The revised KWVS®13 was developed by restructuring the 24-item KWVS through a review process involving eight experts. To validate the reliability and validity of KWVS®13, a self-administered survey comprising KWVS®13, burnout, and depression scales was conducted among 359 service industry workers. KWVS®13 was reclassified, and its reliability and validity were assessed. Receiver operating characteristic curve analysis was performed to establish sex-specific cutoff values (normal vs. risk) of the scale. Results: KWVS®13 consists of 13 items across four subscales: “psychological and sexual violence from customers” (4 items), “psychological and sexual violence from supervisors or coworkers” (4 items), “physical assault from customers, supervisors, or coworkers” (2 items), and “organizational protective system for workplace violence” (3 items). We found that KWVS®13 shows relatively good validity (content validity ratio for content validity: 0.888; success rate of item convergent and discriminant validity: 100%, and significant correlation coefficient with burnout (r = 0.115–0.83, p < 0.05) and depression (r = 0.098–0.348, p < 0.05) with the exception of Organizational Violence Protection System for Workplace Violence) and reliability (Cronbach’s alpha: 0.827–0.860). The reference values for determining risk groups according to the intensity of exposure to workplace violence are presented separately by sex. Conclusions KWVS®13 is a robust and useful measurement tool to objectively and quantitatively assess the intensity and magnitude of workplace violence. It incorporates important considerations for workplace violence assessment and provides a reliable framework for evaluating workplace violence in various professional settings.

Objective: The Huntington’s Disease Quality of Life Battery for Carers (HDQoL-C) is used to evaluate caregiver quality of life. This study aimed to develop and validate the Korean version of the HDQoL-C (K-HDQoL-C) to assess the burden on Korean caregivers of Huntington’s disease (HD) patients. Methods: A total of 19 HD caregivers (7 females, mean age 55.4±14.6 years) participated in this study. The K-HDQoL-C, a translation of the English version, consisted of demographic information, caring aspects, life satisfaction, and feelings about life. It was administered twice, 2 weeks apart. Internal consistency was evaluated using Cronbach’s α, and test-retest reliability was assessed with intraclass correlation coefficients. The relationship with the Zarit Burden Interview-12 (ZBI-12) was analyzed. Results: The internal consistencies of the K-HDQoL-C were 0.771 (part 2), 0.938 (part 3), and 0.891 (part 4). The test-retest reliability ranged from 0.908 to 0.936. Part 3 was negatively correlated with the ZBI-12, and part 4 was positively correlated with the ZBI-12 (r=-0.780, 0.923; p<0.001). Conclusion The K-HDQoL-C effectively evaluates the challenges faced by HD caregivers, particularly in terms of care aspects and life satisfaction.

Background: and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes. Methods: We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data. Results: Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4. Conclusion Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.