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: Patients’ perception of fall risk is a promising new indicator for fall prevention. Therefore, a fall risk perception questionnaire that can be used rapidly and repeatedly in acute care settings is required. This study aimed to develop a short version of the fall risk perception questionnaire (Short-FRPQ) for inpatients. Methods: For the psychometric measurements, 246 inpatients were recruited from an acute care hospital. The construct (using confirmatory factor analysis and discriminant validity of each item), convergent, and known-group validities were tested to determine the validity of the Short-FRPQ. McDonald’s omega coefficient was used to examine the internal consistency of reliability. Results: In the confirmatory factor analysis, the fit indices of the Short-FRPQ, comprising 14 items and three factors, appeared to be satisfactory. The Short-FRPQ had a significantly positive correlation with the original scale, the Korean Falls Efficacy Scale-International, and the Morse Fall Scale. The risk of falls group, assessed using the Morse Fall Scale, had a higher score on the Short-FRPQ. McDonald’s omega coefficient was .90. Conclusion The Short-FRPQ presents good reliability and validity. As patient participation is essential in fall interventions, evaluating the fall risk perception of inpatients quickly and repeatedly using scales of acceptable validity and reliability is necessary.

Objectives: This study aimed to examine the correlations between the regional characteristics of counties in Gangwon Province, Republic of Korea and the ratio of intracounty to extracounty sources of coronavirus disease 2019 (COVID-19) infection. Methods: The region of the infectious contact was analysed for each COVID-19 case reported in Gangwon Province between February 22, 2020 and February 7, 2022. The population, population density, area, the proportion of urban residents, the proportion of older adults (>65 years), financial independence, and the number of adjacent counties were assessed for each of the 18 counties in Gangwon Province. Correlation coefficients between regional characteristics and the ratio of intracounty to extracounty infections were calculated. Results: In total, 19,645 cases were included in this study. The population, population density, proportion of older adults, and proportion of urban residents were significantly correlated with the ratio of intracounty to extracounty infections. A stratified analysis with an age cut-point of 65 years showed that the proportion of older adults had a significant negative correlation with the ratio of intracounty to extracounty infections. In other words, the proportions of extracounty infections were higher in countries with higher proportions of older adults. Conclusion Regions with ageing populations should carefully observe trends in infectious disease outbreaks in other regions to prevent possible transmission.

Background: Information on the effectiveness of nirmatrelvir/ritonavir against the omicron is limited. The clinical response and viral kinetics to therapy in the real world need to be evaluated. Methods: Mild to moderate coronavirus disease 2019 (COVID-19) patients with risk factors for severe illness were prospectively enrolled as a treatment group with nirmatrelvir/ritonavir therapy versus a control group with supportive care. Serial viral load and culture from the upper respiratory tract were evaluated for seven days, and clinical responses and adverse reactions were evaluated for 28 days. Results: A total of 51 patients were analyzed including 40 in the treatment group and 11 in the control group. Faster symptom resolution during hospitalization (P= 0.048) was observed in the treatment group. Only minor adverse reactions were reported in 27.5% of patients. The viral load on Day 7 was lower in the treatment group (P = 0.002). The viral culture showed a positivity of 67.6% (25/37) vs. 100% (6/6) on Day 1, 0% (0/37) vs. 16.7 (1/6) on Day 5, and 0% (0/16) vs. 50.0% (2/4) on Day 7 in the treatment and control groups, respectively. Conclusions Nirmatrelvir/ritonavir against the omicron was safe and resulted in negative viral culture conversion after Day 5 of treatment with better symptomatic resolution.

Purpose: In the intensive care unit, a peripherally inserted central catheter (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulopathies or at high risk of infection. The purpose of this research was to assess the feasibility of bedside ultrasound (US)-guided PICC placement by critical care fellows on intensive care units.
Methods: All bedside US-PICCs inserted by critical care fellows from July 2013 to September 2015 were retrospectively reviewed focusing on the rate of successful insertion, complications of insertion, or during maintenance.
Results: A total of 177 US-guided PICCs were inserted in 163 patients and included in the analysis. The median age was 62 years (IQR 50-70 years) and 104 cases (58.8%) were male. There were 172 cases (90.4%) of PICCs inserted in the upper arm. Anticoagulant therapy was used in 26 patients (14.7%) and 8 patients (5.2%) had severe coagulopathies. The median procedural time was 30 minutes (IQR 19-45 minutes). Insertion success rate was 93.2%, and there were no major complications during insertions except for malposition (12.1%). Catheters remained in place for a total of 3,878 days (median 16 days: IQR 8-31 days). There was only 1 case (0.6%) of catheter-related bloodstream infection, and 2 cases (1.2%) of symptomatic venous thromboembolism.
Conclusion Bedside US-guided placement of PICCs by critical care fellows is safe and feasible. The success rate of the procedure was “acceptable,” and was not associated with significant risks of infectious and non-infectious complications, even in patients with coagulopathies.

Purpose: In the intensive care unit, a peripherally inserted central catheter (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulopathies or at high risk of infection. The purpose of this research was to assess the feasibility of bedside ultrasound (US)-guided PICC placement by critical care fellows on intensive care units.
Methods: All bedside US-PICCs inserted by critical care fellows from July 2013 to September 2015 were retrospectively reviewed focusing on the rate of successful insertion, complications of insertion, or during maintenance.
Results: A total of 177 US-guided PICCs were inserted in 163 patients and included in the analysis. The median age was 62 years (IQR 50-70 years) and 104 cases (58.8%) were male. There were 172 cases (90.4%) of PICCs inserted in the upper arm. Anticoagulant therapy was used in 26 patients (14.7%) and 8 patients (5.2%) had severe coagulopathies. The median procedural time was 30 minutes (IQR 19-45 minutes). Insertion success rate was 93.2%, and there were no major complications during insertions except for malposition (12.1%). Catheters remained in place for a total of 3,878 days (median 16 days: IQR 8-31 days). There was only 1 case (0.6%) of catheter-related bloodstream infection, and 2 cases (1.2%) of symptomatic venous thromboembolism.
Conclusion Bedside US-guided placement of PICCs by critical care fellows is safe and feasible. The success rate of the procedure was “acceptable,” and was not associated with significant risks of infectious and non-infectious complications, even in patients with coagulopathies.

Purpose: The effects of aerobic exercise training on soleus muscle morphology, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in ovariectomized rat skeletal muscle were investigated. Methods: Female Sprague-Dawley rats were divided into control (CON), ovariectomy (OVX), and ovariectomy plus exercise (OVX+EX) groups. After ovarian excision, exercise training was performed using a rat treadmill at 20 m/min, 50 min/day, 5 days/week for 12 weeks. Protein levels of mitochondria-mediated apoptotic signaling and atrophy/hypertrophy signaling in the skeletal muscle (soleus) were examined through western immunoblot analysis. Results: The number of myocytes and myocyte cross-sectional area (CSA) were increased and the extramyocyte space was decreased in the OVX group compared to those in the CON group. However, aerobic exercise training significantly increased myocyte CSA and decreased extramyocyte space in the OVX+EX group compared to those in the OVX group. The protein levels of proapoptotic signaling and muscle atrophy signaling were significantly increased, whereas the protein levels of muscle hypertrophy signaling were significantly decreased in the OVX group compared to that in the CON group. Aerobic exercise training significantly decreased the protein levels of proapoptotic signaling and increased the protein level of antiapoptotic protein in the OVX+EX group compared to that in the OVX group. Aerobic exercise training significantly increased the protein levels of hypertrophy signaling and decreased protein levels of atrophy signaling in the OVX+EX group compared to those in the OVX group. Conclusions Treadmill exercise improved estrogen deficiency-induced impairment in skeletal muscle remodeling, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in skeletal muscle.

Vitamin D insufficiency is associated with obesity and its related metabolic diseases. Adipose tissues store and metabolize vitamin D and expression levels of vitamin D metabolizing enzymes are known to be altered in obesity. Sequestration of vitamin D in large amount of adipose tissues and low vitamin D metabolism may contribute to the vitamin D inadequacy in obesity. Vitamin D receptor is expressed in adipose tissues and vitamin D regulates multiple aspects of adipose biology including adipogenesis as well as metabolic and endocrine function of adipose tissues that can contribute to the high risk of metabolic diseases in vitamin D insufficiency. We will review current understanding of vitamin D regulation of adipose biology focusing on vitamin D modulation of adiposity and adipose tissue functions as well as the molecular mechanisms through which vitamin D regulates adipose biology. The effects of supplementation or maintenance of vitamin D on obesity and metabolic diseases are also discussed.

The myelination of axons in the vertebrate nervous system through oligodendrocytes promotes efficient axonal conduction, which is required for the normal function of neurons. The central nervous system (CNS) can regenerate damaged myelin sheaths through the process of remyelination, but the failure of remyelination causes neurological disorders such as multiple sclerosis. In mammals, parenchymal oligodendrocyte progenitor cells (OPCs) are known to be the principal cell type responsible for remyelination in demyelinating diseases and traumatic injuries to the adult CNS. However, growing evidence suggests that neural stem cells (NSCs) are implicated in remyelination in animal models of demyelination. We have previously shown that olig2+ + radial glia (RG) have the potential to function as NSCs to produce oligodendrocytes in adult zebrafish. In this study, we developed a zebrafish model of adult telencephalic injury to investigate cellular and molecular mechanisms underlying the regeneration of oligodendrocytes. Using this model, we showed that telencephalic injury induced the proliferation of olig2+ + RG and parenchymal OPCs shortly after injury, which was followed by the regeneration of new oligodendrocytes in the adult zebrafish. We also showed that blocking Notch signaling promoted the proliferation of olig2+ RG and OPCs in the normal and injured telencephalon of adult zebrafish. Taken together, our data suggest that Notch-regulated proliferation of olig2+ RG and parenchymal OPCs is responsible for the regeneration of oligodendrocytes in the injured telencephalon of adult zebrafish.