Dietary protein is a crucial macronutrient for systemic homeostasis, and the global interest in protein supplements has surged because of their roles in muscle synthesis, immune function, and sarcopenia prevention. In South Korea, the proportion of energy derived from protein has increased steadily over the past decade, reflecting a significant shift in dietary patterns toward greater reliance on protein. Concurrently, a wide range of protein- and amino acidbased processed foods and dietary supplements has been developed and actively consumed.Nevertheless, comprehensive data on the prevalence of protein supplement users, their characteristics across different life stages, and the contribution of supplements to total daily protein requirements are lacking. Unlike other macronutrients, the human body lacks a dedicated reservoir for protein storage, necessitating a continuous dietary supply to support protein turnover, particularly for older adults facing anabolic resistance and individuals with high physical demands. Although clinical evidence highlights that protein supplementation, particularly when combined with resistance exercise, effectively improves muscle mass and physical performance, the magnitude of these benefits remains inconsistent across different life stages and protein sources. Conversely, emerging concerns about the potential metabolic risks from chronic overconsumption suggest that the validity and safety of protein supplementation are unclear, highlighting the need for a precision nutrition approach. Thus, this review evaluates the status of protein supplement intake among Koreans, synthesizes evidence on its physiological benefits and drawbacks and examines international trends and regulatory frameworks. Developed as part of the technical assessment for the 2025 revision of the Dietary Reference Intakes for Koreans, this review addresses the current lack of longterm safety data on chronic protein overconsumption. It provides a foundational framework for evidence-based dietary guidelines and serves as a critical scientific basis for establishing future tolerable upper intake levels and nutrition policies for protein supplement use in Korea.

BACKGROUND/OBJECTIVES: Postpartum bone metabolism undergoes substantial alterations based on breastfeeding status. Research on maternal calcium intake and bone recovery, particularly among Asian women, remains limited. This study investigated postpartum change in bone mineral density (BMD) and its association with calcium intake during late pregnancy and post-delivery according to breastfeeding status. SUBJECTS/METHODS: Thirty-six women (22 breastfeeding, 14 non-breastfeeding) underwent dual-energy X-ray absorptiometry 3 times: 1) within 3 days of delivery, 2) at 6 mon postpartum for non-breastfeeding women or within 1 mon of weaning for breastfeeding women, and 3) at 12 mon postpartum. Dietary calcium intake was evaluated using a food frequency questionnaire and dietary supplement survey at all visits. Association between calcium intake with percentage change in BMD (%ΔBMD) was assessed by linear regression. RESULTS: The BMD at the lumbar spine, total hip, femoral neck, and trochanter significantly decreased during breastfeeding, whereas non-breastfeeding women displayed increased BMD at the femoral neck at 6 mon postpartum. In non-breastfeeding women, postpartum calcium intake was positively associated with %ΔBMD at the total hip, femoral neck, and intertrochanter (P < 0.05). Few significant associations were observed between %ΔBMD and late pregnancy intakes across all women, regardless of breastfeeding status. At 12 mon, BMD in breastfeeding women recovered to delivery levels, while non-breastfeeding women maintained their BMD observed at 6 mon postpartum. CONCLUSION Postpartum calcium intake is positively associated with bone recovery in non-breastfeeding women, suggesting that its effects on bone recovery potentially vary with lactation status.

Background: A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period. Methods: We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression. Results: Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated. Conclusion In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.

Penetrating cardiac foreign body injuries are infrequent but potentially life-threatening occurrences. This paper presents a brief case report of a patient who presented to the emergency department (ED) with self-inflicted injuries. A 14-cm cylindrical hollow stick was embedded into his right ventricle. Remarkably, the patient remained hemodynamically stable and showed no significant symptoms. The clinical manifestations of penetrating cardiac foreign body injuries may vary from a stable hemodynamic condition to a rapid cardiovascular collapse. A penetrating cardiac foreign body is a rare traumatic injury encountered in the ED. Nevertheless, an awareness of this case is essential because it provides insights into the diversity of presentations of cardiac foreign body injuries. Although these injuries often manifest with severe symptoms such as cardiac tamponade, massive hemothorax, or even cardiac arrest, this case shows that patients may remain hemodynamically stable and asymptomatic, making a diagnosis challenging.

Janus kinase (JAK) inhibitors are an important treatment option for ulcerative colitis, providing rapid onset of action, oral administration, and efficacy even after biologic failure. The 3 approved agents—tofacitinib, filgotinib, and upadacitinib—differ in JAK isoform selectivity, leading to clinically meaningful differences in efficacy and safety. Evidence from network meta-analyses, clinical trials, and real-world studies consistently shows that upadacitinib provides the highest efficacy for induction and maintenance of remission, whereas filgotinib demonstrates the most favorable safety profile. The strong efficacy of upadacitinib and tofacitinib is particularly relevant in patients with severe disease, including acute severe ulcerative colitis, and upadacitinib maintains high efficacy regardless of prior advanced therapy exposure. JAK inhibitors also benefit extraintestinal manifestations. Although risks such as herpes zoster, serious infection, thromboembolism, and major cardiovascular events differ among agents, long-term data suggest generally acceptable safety when used appropriately. Intraclass JAK-to-JAK cycling is feasible, with about half of patients achieving steroid-free clinical remission in retrospective cohorts. Based on mechanistic, clinical, and real-world evidence, filgotinib may be a first-line option for patients with lower disease activity or when safety is a priority, whereas upadacitinib or tofacitinib may be preferred in higher disease activity. Strategically selecting agents may improve durability and outcomes.

Objective: This study aimed to develop a reliable and valid Mixed State Severity Index (MSSI) to assess mood instability in patients with mood disorders and determine cutoff scores. Methods: Twenty-one items were selected based on Koukopoulos’ criteria for mixed depressive episode, historically referred to as agitated depression, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision mixed features criteria. The MSSI was administered to 242 patients (major depressive disorder [n=92], bipolar disorder [BD] I [n=78], and BD II [n=72]) and 726 controls. Results: The MSSI demonstrated high internal consistency (α=0.78–0.90). Exploratory factor analysis revealed a stable four-factor structure. Based on receiver operating characteristic analysis, optimal cutoff scores were identified to distinguish mood disorder groups from controls, ranging from 19.5 to 27.5 depending on diagnosis. Conclusion The MSSI is a reliable and valid instrument for assessing the severity of mixed features in patients with mood disorders. The established cutoff scores enhance its clinical utility, providing robust diagnosis and treatment planning support.

Objective: Patients with panic disorder (PD) are approximately four times more likely than the general population to exhibit suicidal ideation (SI) and suicide attempts. Although prolonged duration of untreated illness (DUI) is a known risk factor for adverse outcomes in mood disorders, its impact on suicidality among patients with PD has not been well established. This study investigated whether prolonged DUI is associated with heightened SI among patients with PD, considering sociodemographic and clinical factors. Methods: A total of 804 patients with PD were recruited. DUI was defined as the time between symptom onset and the initiation of psychiatric treatment. Clinical assessments included the Scale for Suicide Ideation (SSI), Beck Depression Inventory-II (BDI-II), and Panic Disorder Severity Scale. Sociodemographic and clinical predictors of SI were examined using independent t-tests, Pearson’s correlations, and multiple regression analysis. Results: In patients with PD, the mean DUI was 41.56 months. Longer DUI was positively correlated with higher SSI total scores, along with greater depression severity. Gender women, unmarried status, and elevated BDI-II scores were significantly predicted higher SSI total scores. In the multiple regression model, prolonged DUI remained an independent predictor of SSI (B=0.116, p=0.012) after adjusting for other variables. Conclusion These findings indicate that delayed treatment contributes to increased suicidality in PD, beyond demographic and depressive risk factors. Therefore, early detection and timely intervention using treatment strategies that enhance awareness, improve the accessibility of psychiatric services, and provide social support may reduce DUI and mitigate suicide risk among patients with PD.

Background: Liver transplantation (LT) is the standard treatment for end-stage liver disease; however, it can lead to biliary strictures in 25%–30% of cases. We aimed to develop a biodegradable stent loaded with paclitaxel that could be inserted during surgery without requiring removal. We evaluated the safety and efficacy of this stent using a porcine model. Methods: Fourteen pigs underwent simulated ischemic injury during LT, and a biodegradable paclitaxel-eluting stent was inserted after duct-to-duct anastomosis.Pigs were divided into four groups: no stent (n=3), bare stent (n=3), 300 µg paclitaxel stent (n=4), and 900 µg paclitaxel stent (n=4). After 3 months of follow-up, autopsies were conducted to obtain common bile duct tissue samples, and inflammation and fibrosis thicknesses were assessed under a microscope. Results: Most tissues had resolved the inflammatory reactions by the 3-month mark. The thinnest fibrosis thickness was observed in the 900 µg group (359.08±167.23 µm); however, no statistical significance was observed. Conclusion This study demonstrated the safety of paclitaxel-eluting biodegradable biliary stents and their positive effects on fibrosis in an ischemic bile duct porcine model. This biodegradable stent represents a potential approach for overcoming the complications associated with biliary strictures after LT.

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.