Arterial pH reflects both metabolic and respiratory distress in cardiac arrest and has prognostic implications. However, it was excluded from the 2024 update of the Utstein out-of-hospital cardiac arrest (OHCA) registry template. We investigated the rationale for including arterial pH into models predicting clinical outcomes. Methods: Data were sourced from the Korean Cardiac Arrest Research Consortium, a nationwide OHCA registry (NCT03222999). Prediction models were constructed using logistic regression, random forest, and eXtreme Gradient Boosting frameworks. Each framework included three model types: pH, low-flow time, and combined models. Then the area under the receiver operating characteristic curve (AUROC) of each predicting model was compared. The primary outcome was 30- day death or neurologically unfavorable status (cerebral performance category ≥3). Results: Among the 15,765 patients analyzed, 92.2% experienced death or unfavorable neurological outcomes. The predicting performance of the models including pH (AUROC, 0.92–0.94) were comparable to the models including low-flow time in all frameworks (0.93–0.94) (all P>0.05). Inclusion of pH into low-flow time models consistently showed higher AUROCs than individual models in all frameworks (AUROC, 0.93–0.95; all P<0.05). Conclusions: The predicting performance of models including arterial pH was comparable to models including low-flow time, and addition of arterial pH into low-flow time models could increase the performance of the models. Key Words: blood pH; hydrogen-ion con

Background: The exposome encompasses all factors people encounter through life, with the skin constantly exposed. While particulate matter (PM) and sleep deprivation are known to contribute to barrier dysfunction, their combined effects remain unclear. Objective: To evaluate the independent and combined effects of PM exposure and short-term sleep deprivation on skin barrier function. Methods: Forty healthy Korean women (aged 24–58 years) were enrolled in this study. Forearms were divided into 4 sites: control, PM exposure, sleep deprivation, and PM plus sleep deprivation. Parameters such as trans-epidermal water loss (TEWL), hydration, elasticity, roughness, and redness were measured at baseline and post-exposure. RNA sequencing and reverse transcription-polymerase chain reaction were conducted on tape-stripped skin samples. Results: PM exposure significantly increased TEWL (+25.59%, p<0.01), roughness (+21.9%, p<0.01), and redness (+13.7%, p<0.0001) while reducing elasticity (−3.98%, p<0.01). Sleep deprivation modestly reduced elasticity (−1.39%, p<0.05) without affecting other parameters.Combined PM and sleep deprivation did not further exacerbate barrier dysfunction compared to PM alone. RNA sequencing revealed reduced FLG and LORICRIN expression and upregulated endoplasmic reticulum (ER) stress markers (HSP90B1, CANX) in both PM and sleep deprivation conditions. Conclusion PM exposure impaired skin barrier function, while short-term sleep deprivation alone did not significantly affect the barrier, either independently or in combination with PM.However, it was observed that the sleep deprivation-only, while not directly causing barrier damage, induced changes in ER stress-related gene expression in tape-stripped skin samples, like the PM exposure-only. This suggests that such signaling pathways could potentially exacerbate skin barrier deterioration.

Background: Ensuring reference material (RM) commutability is crucial for evaluating measurement traceability in order to standardize laboratory tests. However, commutability assessment is not routinely performed. We assessed whether RMs prepared following CLSI C37-A guidelines could be used without assessing commutability by evaluating their commutability for four lipid measurements using the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and CLSI EP14 protocols. Methods: We analyzed total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in frozen sera from 20 individuals and 11 RMs, prepared by the Korea Disease Control and Prevention AgencyLaboratory Standardization Project (per CLSI C37-A), using six routine measurement procedures (MPs). Regression equations and 95% prediction intervals derived from single-donor sera were analyzed following CLSI EP14. The IFCC protocol was used to assess differences in inter-MP biases between RM and clinical samples. The effect of the TG concentration on commutability was evaluated by analyzing biases between MP results and reference procedure-assigned values. Results: RMs were commutable for most MP pairs for TC and TG. Commutability for HDL-C and LDL-C varied across RMs, with RM10 and RM11 showing higher TG levels (2.38 and 2.95 mmol/L, respectively) and lower commutability. Increased bias percentages from assigned values were observed for RMs with higher TG levels. Conclusions RMs prepared per CLSI C37-A were commutable with most MP pairs for TC and TG. Elevated TG levels affected HDL-C and LDL-C commutability, highlighting the need to consider TG concentrations during RM preparation and assess commutability to standardize laboratory tests.

Background: Pig red blood cells (RBCs) are rapidly eliminated when transfused into nonhuman primates (NHPs) because of immune reactions involving antibody binding and complement activation. We assessed the relationship between post-transfusion hemolysis and complement activation. Methods: RBCs for transfusion were prepared from wild-type (WT) and genetically modified pigs and NHPs. After the withdrawal of 25% of the blood volume, NHPs received transfusions of WT (N = 4), triple knockout (TKO, N = 8), and TKO pig RBCs expressing human CD55 and CD39 (TKO/hCD55.hCD39, N = 4). Additional groups received repeated xenotransfusions (ReXTf, N = 3), NHP RBC transfusions (N = 3), or a saline infusion (N = 4).Blood samples were collected at multiple time points to measure Hb and complement fragment (C3a, C4a, and factor Bb) levels and agglutination titers. Results: Hb levels were restored by transfusions but not by saline infusion. The degree of complement activation varied with the type of transfused RBCs, with significant increases in C3a and factor Bb levels immediately after xenotransfusions but not allotransfusions.These increases were particularly notable in ReXTf and negatively correlated with Hb levels on post-transfusion day 1 (ρ = –0.547 and –0.556; P = 0.0187 and 0.0165, respectively).In TKO/hCD55.hCD39 pig RBC transfusions, C3a and factor Bb peak levels were delayed until post-transfusion day 3, unlike in TKO pig RBC transfusions. Conclusions Post-transfusion complement activation varies depending on prior sensitization and genetic modifications in pig RBCs. Monitoring complement activation can provide insight into the survival and compatibility of transfused RBCs in NHPs.

Background: Fishing is a physically demanding occupation with a high risk of musculoskeletal disabilities (MSDs). Although previous studies have focused on ergonomic risk factors, little attention has been paid to sex differences in the prevalence of MSDs among fishers. This study aimed to assess whether female fishers experience a higher prevalence of MSDs than male fishers and to examine whether this difference persists after adjusting for socioeconomic and occupational factors. Methods: We analyzed cross-sectional data from 898 Korean fishers (513 men and 385 women) who participated in the 2021–2022 Fisher Health Survey. MSDs in the upper extremities, lower back, and knees were defined as scores in the top 25% of the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), Oswestry Disability Index, and Western Ontario and McMaster Universities Arthritis Index Short Form (WOMAC-SF), respectively. Modified Poisson regression was used to calculate the prevalence ratios (PRs) by sex, with stepwise adjustments for age, socioeconomic factors, and occupational factors. Results: Female fishers had significantly higher MSD risk than male fishers across all body regions (fully adjusted PRs: upper extremity, 1.59; lower back, 1.63; knee, 1.44). Sex disparities were most pronounced among those under 60 years of age and remained significant even in older age groups. Conclusions The elevated MSD risk among female fishers persisted despite adjusting for conventional risk factors, suggesting the influence of additional factors such as biological susceptibility, domestic labor, and gendered health reporting. Therefore, MSD prevention strategies should include sex-sensitive multidimensional approaches beyond ergonomic interventions.

Purpose: This study aimed to evaluate the effects of an intervention combining warm therapy (via a thermoelectric-element tourniquet) and a distraction-based approach (via an augmented reality-based app known as TWINKLE) on pain, stress, and satisfaction during intravenous catheterization in adults. Methods: A randomized controlled trial was conducted in South Korea with 93 healthy adults who were randomly assigned to one of three groups: the experimental group (TWINKLE app with warm therapy), the comparison group (warm therapy only), and the control group (no treatment). Participants’ pain, stress, and satisfaction, as well as practitioner satisfaction, were measured after the intervention. Results: Pain scores differed significantly among the three groups (F = 5.68, p = .005), with the experimental group showing significantly lower scores than the control group (p = .003). Stress levels were also significantly lower in the experimental group than in the other groups (F = 9.42, p < .001). Participant satisfaction was highest in the experimental group (F = 17.65, p < .001), while nurse satisfaction was significantly higher in the comparison group than in the experimental and control groups (F = 67.91, p < .001), suggesting that the additional distraction intervention may have increased nurses’ workload. Conclusion Combining digital distraction with warm therapy using a thermoelectric-element tourniquet effectively reduces pain and stress while improving patient satisfaction during intravenous catheterization. Further research is needed to optimize this approach, with a particular focus on targeting digital distraction interventions to patients with higher levels of procedural anxiety and finding ways to minimize practitioner workload.

Background: Despite efforts by the National Education on Sleeping Environment to reduce sudden infant death syndrome (SIDS), it remains the leading cause of post-neonatal mortality. In Korea, the incidence of SIDS was estimated at 0.4 per 1,000 infants in 2022. Mutations in the ryanodine receptor 2 ( RYR2) gene, known to be associated with catecholaminergic polymorphic ventricular tachycardia, have been implicated in cases of sudden death. However, genetic studies investigating the link between RYR2 mutations and SIDS have not been conducted in Korea. Methods: We extracted DNA from archived formalin-fixed, paraffin-embedded myocardial tissues from 249 SIDS cases autopsied between 2005 and 2017. DNA analysis focused on sequencing key exons (3, 8, 14, 15, 37, 42, 44–47, 49, 50, 83, 87–91, 93–95, 97, 99, and 100–105) of the RYR2 gene, critical for its functional role. Results: Among the 249 SIDS cases, 62% were male infants, with an average age of 124 days, all of Asian-Korean descent. We identified two previously unreported RYR2 variants in two Korean patients with SIDS, namely c.13175A>G (p.Lys4392Arg) and c.4652A>G (p.Asn1551Ser). Conclusion Our study identified two RYR2 variants (c.13175A>G/p.Lys4392Arg and c.4652A>G/p.Asn1551Ser) associated with SIDS through postmortem genetic analysis.Given the limited diagnostic yield, our findings underscore the importance of selectively performing molecular autopsies in cases with documented familial clinical history. This approach aims to enhance the quality of genetic counseling available to affected families.

Background: We evaluated severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-specific humoral and cellular responses for up to 6 months after the 3rd dose of ancestral coronavirus disease 2019 (COVID-19) vaccination in people living with HIV (PLWH) and healthy controls (HCs) who were not infected with COVID-19. Methods: Anti-spike receptor-binding domain IgG (anti-RBD IgG) concentrations using chemiluminescence immunoassay and neutralizing antibodies using focus reduction neutralization test (FRNT) were assessed at 1 week after each dose of vaccination, and 3 and 6 months after the 3rd dose in 62 PLWH and 25 HCs. T-cell responses using intracellular cytokine stain were evaluated at 1 week before, and 1 week and 6 months after the 3rd dose. Results: At 1 week after the 3rd dose, adequate anti-RBD IgG (> 300 binding antibody unit /mL) was elicited in all PLWH except for one patient with 36 CD4 T-cell count/mm3 . The geometric mean titers of 50% FRNT against wild type (WT) and omicron BA.5 strains of SARS-CoV-2 in PLWH with CD4 T-cell count ≥ 500 cells/mm3(high CD4 recovery, HCDR) were comparable to HC, but they were significantly decreased in PLWH with CD4 T-cell count < 500/mm3 (low CD4 recovery, LCDR). After adjusting for age, gender, viral suppression, and number of preexisting comorbidities, CD4 T-cell counts < 500/mm3 significantly predicted a poor magnitude of neutralizing antibodies against WT, omicron BA.5, and XBB 1.5 strains among PLWH. Multivariable linear regression adjusting for age and gender revealed that LCDR was associated with reduced neutralizing activity (P = 0.017) and interferon-γ-producing T-cell responses (P = 0.049 for CD T-cell; P = 0.014 for CD8 T-cell) against WT, and strongly associated with more decreased cross-neutralization against omicron BA.5 strains (P < 0.001). Conclusion HCDR demonstrated robust humoral and cell-mediated immune responses after a booster dose of ancestral SARS-CoV-2 vaccine, whereas LCDR showed diminished immune responses against WT virus and more impaired cross-neutralization against omicron BA.5 strain.

Background: Currently, little is known about the relationship between the temporal radiographic latent trajectories, which are based on the extent of coronavirus disease 2019 (COVID-19) pneumonia and clinical outcomes. This study aimed to elucidate the differences in the temporal trends of critical laboratory biomarkers, utilization of critical care support, and clinical outcomes according to temporal radiographic latent trajectories. Methods: We enrolled 2,385 patients who were hospitalized with COVID-19 and underwent serial chest radiographs from December 2019 to March 2022. The extent of radiographic pneumonia was quantified as a percentage using a previously developed deep-learning algorithm. A latent class growth model was used to identify the trajectories of the longitudinal changes of COVID-19 pneumonia extents during hospitalization. We investigated the differences in the temporal trends of critical laboratory biomarkers among the temporal radiographic trajectory groups. Cox regression analyses were conducted to investigate differences in the utilization of critical care supports and clinical outcomes among the temporal radiographic trajectory groups. Results: The mean age of the enrolled patients was 58.0 ± 16.9 years old, with 1,149 (48.2%) being male. Radiographic pneumonia trajectories were classified into three groups: The steady group (n = 1,925, 80.7%) exhibited stable minimal pneumonia, the downhill group (n = 135, 5.7%) exhibited initial worsening followed by improving pneumonia, and the uphill group (n = 325, 13.6%) exhibited progressive deterioration of pneumonia. There were distinct differences in the patterns of temporal blood urea nitrogen (BUN) and C-reactive protein (CRP) levels between the uphill group and the other two groups. Cox regression analyses revealed that the hazard ratios (HRs) for the need for critical care support and the risk of intensive care unit admission were significantly higher in both the downhill and uphill groups compared to the steady group. However, regarding in-hospital mortality, only the uphill group demonstrated a significantly higher risk than the steady group (HR, 8.2; 95% confidence interval, 3.08–21.98). Conclusion Stratified pneumonia trajectories, identified through serial chest radiographs, are linked to different patterns of temporal changes in BUN and CRP levels. These changes can predict the need for critical care support and clinical outcomes in COVID-19 pneumonia.Appropriate therapeutic strategies should be tailored based on these disease trajectories.