Background: The accurate laboratory-based detection of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is essential for effective patient management and infection control in the post–coronavirus disease 2019 era. In this study, the performance of the PowerChek Respiratory Virus Panels 1–4 assay (Kogene Biotech) in detecting non-SARS-CoV-2 respiratory viruses and SARS-CoV-2 was compared with those of two established commercial assays. Methods: Residual clinical respiratory specimens collected between December 2023 and February 2024 were retested using the PowerChek assay. Of the 129 specimens retested, 80 had tested positive for 14 non-SARS-CoV-2 respiratory virus targets in the Allplex Respiratory Panels 1–3 assay (Seegene) and 49 had been tested using the Alinity m SARS-CoV-2 assay (Abbott; 20 positive and 29 negative for SARS-CoV-2). Agreement, Cohen’s kappa, and discordant results were assessed. Results: For the 14 non-SARS-CoV-2 respiratory virus targets, the virus-specific overall percent agreement (OPA) ranged from 95.0% to 100%, the positive percent agreement (PPA) ranged from 66.7% to 100%, and the negative percent agreement (NPA) ranged from 96.0% to 100%, with kappa values of 0.64–1.00. Lower agreements were observed for human coronavirus OC43 and influenza A virus. For SARS-CoV-2 detection, the OPA was 98.0% (PPA, 95.0%; NPA, 100%; kappa, 0.96). Conclusion The detection performance of the PowerChek assay was comparable to those of the established assays for most respiratory virus targets, with lower agreement observed for some targets. These features support its practical utility for the routine multiplex molecular detection of respiratory viruses, including SARS-CoV-2.

Background: s/Aims: Phase angle (PhA), as measured by bioelectrical impedance analysis, provides insights into hydration and nutritional status, making it a prognostic indicator of frailty. While low preoperative PhA has been linked to postoperative complications in cancer patients, its predictive value in individuals undergoing pancreaticoduodenectomy (PD) has not been thoroughly investigated.This study aims to evaluate the clinical utility of preoperative PhA in predicting postoperative complications for patients undergoing PD. Methods: Among 41 patients who underwent PD at Seoul National University Hospital between September and December 2024, 35 were included in the analysis after excluding 6 patients who had concomitant blood vessel or other organ resections. Patients were divided into low (Comprehensive Complication Index [CCI] ≤ 20) and high (CCI > 20) complication groups based on the CCI, derived from the Clavien–Dindo classification. The differences in PhA between the two groups were analyzed, and logistic regression was performed to assess the relationship between PhA and CCI. Results: The mean PhA was significantly lower in the high-CCI group compared to the low-CCI group (5.7° vs. 6.7°, p = 0.025). Multivariate logistic regression analysis indicated that PhA (odds ratio: 0.17; 95% confidence interval: 0.04–0.68; p = 0.012) was an independent predictor of high CCI. A low preoperative PhA was associated with an increased risk of postoperative complications following PD. Conclusions Preoperative PhA may serve as a valuable predictive indicator of postoperative complications after PD, enabling the identification of patients who could benefit from preoperative prehabilitation, including nutritional support.

Background: Despite widespread vaccination efforts against severe acute respiratory syndrome coronavirus 2, variants with increased transmissibility or immune evasion continue to emerge, posing a considerable challenge. Understanding the immunological factors associated with coronavirus disease (COVID-19) progression is essential for improving patient management and treatment strategies. We explored the dynamic changes in the peripheral white blood cell (WBC) profile, including T lymphocyte subsets, to assess their potential as predictors of disease severity and progression. Methods: Two hundred fifty-eight patients hospitalized for confirmed COVID-19 were classified into four sub-cohorts based on changes in disease severity over 7 days. WBC parameters, including absolute neutrophil, total lymphocyte, and T cell subset counts, and the neutrophil-to-lymphocyte ratio (NLR) were assessed at admission and after 7 days. Results: Patients with persistent mild-to-moderate illness exhibited a marked increase in the lymphocyte count and a decrease in the NLR over time. In contrast, patients with sustained severe-to-critical illness showed an increasing WBC count without a corresponding increase in the lymphocyte count, in addition to a marked elevation in the NLR. Patients whose condition improved from severe-to-critical to mild-to-moderate illness showed increased cluster of differentiation (CD)3+ and CD4+ T cell counts and an elevated CD4/CD8 ratio, whereas the NLR did not significantly change. Conclusions The early-phase dynamics of T cell subsets may serve as a useful biomarker of disease severity and recovery in patients with COVID-19. Monitoring these immunological changes may help support clinical decision-making and inform the timing of therapeutic interventions.

Background: Perfluoroalkyl substances (PFAS) are used in various products, and PFAS have been detected in outdoor clothing. PFAS can be absorbed into the human body via oral ingestion, inhalation, and dermal contact. In this study, we examined the association between the frequency of using outdoor clothing and serum PFAS concentrations in the Korean population using data from cycle 4 (2018–2020) of the Korean National Environmental Health Survey. Methods: Data from 2,993 adult participants were analyzed. The participants were classified into low-concentration and high-concentration groups based on the 75th percentile concentration of serum PFAS. The use of outdoor clothing was categorized into three groups: non-use, <4 times a week, and ≥4 times a week. The odds ratio (OR) for serum PFAS levels associated with use of outdoor clothing was determined through logistic regression analysis, adjusted for demographic characteristics, health-related factors, PFAS-treated items, dietary factors, and ventilation time. Results: ORs for high serum PFAS were higher in groups using outdoor clothing compared to the non-user group. In males, the adjusted ORs for the < 4 times a week and ≥ 4 times a week outdoor clothing usage group were as follows: perfluorooctanoic acid (PFOA), 1.26 (95% confidence interval [CI]: 1.10–1.44) and 1.70 (1.40–2.07); perfluorohexanesulfonic acid (PFHxS), 1.49 (1.16–1.92) and 1.70 (1.22–2.37); and perfluorononanoic acid (PFNA), 1.34 (1.19–1.51) and 1.68 (1.38–2.05), respectively. In females, the respective ORs were as follows: PFOA 1.32 (95% CI: 1.19–1.46) and 1.53 (1.01–2.32); PFHxS, 1.46 (1.08–1.96) and 2.63 (2.10–3.29); PFNA, 1.38 (1.22–1.55) and 1.45 (1.07–1.96). Conclusions In adults, elevated serum PFAS levels were associated with increased frequency of using outdoor clothing.

Purpose: The Dietary Reference Intakes for Koreans (KDRIs) serve as a foundation for nutrition policy, nutrition education, and dietary intake evaluation among healthy Koreans.The KDRIs are revised every five years to ensure that the guidelines are based on a robust and up-to-date scientific foundation. For the 2025 KDRIs for calcium, the 2020 KDRIs were revisited, and references were critically evaluated. Methods: All references cited in the 2020 KDRIs were extracted, reviewed, and organized according to the framework for the estimated average requirement (EAR). Each reference was evaluated based on the participant characteristics, including age, race/ethnicity, and health status, as well as study design, exposure, and outcomes. In addition, calculations for the EAR and Recommended Nutritient Intakes were re-examined for each sex and age group and compared with the current literature. Results: Major revisions in the 2025 KDRIs were driven by updates in the reference bodyweight, improved consistency in rounding and coefficients of variation, inclusion of studies in East Asian populations, and clarification of the use of calcium balance studies.Nevertheless, further studies in Koreans, particularly in pregnant and lactating women, are needed to strengthen the scientific evidence for the calcium DRI. Conclusion The 2025 KDRIs for calcium were revised to be based on more robust logical reasoning and calculation methods. Future research conducted on Korean populations is necessary to define the calcium requirements for Koreans more accurately.

Myiasis, a parasitic infestation caused by dipteran larvae in living humans or animals, is rarely encountered postmortem. Here, we report a case of myiasis identified during postmortem inspection in a 40-year-old man with a 10-year history of untreated schizophrenia. During the winter between late 2022 and early 2023, the decedent walked outdoors barefoot and sustained frostbite and was advised to undergo limb amputation at a university hospital in March 2024. He died at home in late May 2024. At the scene, the body showed displaceable livor mortis and absence of rigor mortis, suggesting a short postmortem interval. Severe necrosis was present below the knees, and numerous third-instar larvae without postfeeding stage were observed within the necrotic tissue, suggesting myiasis development at the frostbite sites. Species identification via larval sampling was not possible; thus, photographic analysis was attempted. The larva at the most advanced developmental stage was most likely a third-instar Lucilia sericata, the most common species causing myiasis in Korea. Assuming a skin temperature of 34°C under blanket coverage, the estimated post-oviposition interval ranged from 38.9–71.7 hours. Considering the estimated postmortem interval, the oviposition may have occurred antemortem. Since myiasis can indicate neglect or contribute to death, forensic pathologist should assess whether the postmortem interval aligns with the developmental stage of the larvae. For accurate forensic entomological analysis, adequate sampling of larvae is essential during postmortem inspections.

Objective: To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines. Materials and Methods: This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022. Results: A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018. Conclusion The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.