Background/Aims: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

Purpose: Research on depressive symptoms among older workers is limited. This study aimed to explore the relationships between demographics, job characteristics, psychosocial work environment factors, and depressive symptoms in older workers, and to identify the factors that influence these symptoms. Methods: This secondary analysis used data from the 7th Korean Working Conditions Survey, focusing on 7,238 workers aged 55 years or older, after excluding missing values from an initial sample of 10,778 individuals. Depressive symptoms were assessed using the Korean version of the World Health Organization-Five Well-Being Index. Data analysis involved cross-tabulation, general linear modeling, and both univariate and multivariate logistic regression analyses using complex sample designs. Results: Depression scores were categorized into depressed (n=2,490, weighted %=35.3%) and non-depressed (n=4,748, weighted %=64.7%) groups based on a cutoff score of less than 13, which indicates poor mental well-being. Complex-sample multivariate logistic regression analysis identified several significant factors influencing depressive symptoms, including education level (middle school odds ratio [OR]=1.56), perceived health status (fair OR=1.63, poor OR=2.95), reflection of opinions and taking breaks during work (OR=0.93 and OR=0.97, respectively), colleagues’ support (OR=0.85), job insecurity (OR=1.04), and satisfaction with the work environment (OR=1.47). Conclusion Older workers, especially people with a middle school education or less, were more vulnerable to the risk of developing depression. To mitigate and prevent depressive symptoms, it is essential to implement individual-level strategies—such as health promotion and employee assistance programs, and counseling services—alongside organizational-level measures, including the expansion of job autonomy and supportive workplace policies for older workers.

Purpose: This study conducted a systematic analysis of the effects of virtual reality (VR)-based simulation education on nursing students’ learning outcomes. Methods: Studies involving undergraduate nursing students who received immersive or non-immersive VR–based simulation education, compared with conventional nursing education, were identified from Cochrane CENTRAL, EMBASE, PubMed, CINAHL, ACM Digital Library, NDSL, KISS, DBpia, and RISS, from database inception through February 28, 2025. The primary outcomes were nursing skill performance and knowledge, while the secondary outcomes were self-efficacy and confidence in nursing performance. Only randomized controlled trials were included. A total of 21 studies met the inclusion criteria and were synthesized using a random-effects meta-analysis. Effect sizes were calculated as standardized mean differences (SMDs) with 95% confidence intervals (CIs). Results: Across 21 randomized controlled trials, the meta-analysis showed that VR-based simulation education had no statistically significant effects on nursing skill performance (n = 759, SMD = 0.18; 95% CI: −0.47 to 0.82) or confidence in nursing performance (n = 1,157, SMD = 0.12; 95% CI: −0.20 to 0.43). In contrast, statistically significant positive effects were observed for knowledge (n = 1,009, SMD = 0.32; 95% CI: 0.08 to 0.57) and self-efficacy (n = 696, SMD = 0.46; 95% CI: 0.11 to 0.81). Conclusion VR-based simulation education represents an effective educational approach for improving nursing students’ knowledge and self-efficacy. Future implementations should align the type and complexity of VR simulations with specific educational goals and content, while accounting for potential variation related to instructional design, learner characteristics, and outcome measures.

This study aimed to identify sex-specific sarcopenia risk groups among older adults. Methods: Data were obtained from 1,870 Korean adults aged 65 years or older who participated in the Korea National Health and Nutrition Examination Survey between 2022 and 2023. Sarcopenia was evaluated based on hand grip strength and skeletal muscle mass. Statistical analyses incorporating complex sample methods, along with decision tree analysis, were conducted using SPSS version 29.0. Results: The prevalence of reduced muscle strength, decreased muscle mass, and sarcopenia was 14.7%, 30.2%, and 8.1%, respectively. Sarcopenia was observed in 6.4% of men and 9.7% of women. In men, eleven sarcopenia risk pathways were identified based on age, anemia, education level, body mass index (BMI), perceived health status, hemoglobin A1c, diabetes, diastolic blood pressure, income, living status, acceptable macronutrient distribution range (AMDR) for protein, and aerobic exercise. The strongest predictor of sarcopenia risk in men was age ≥ 77 years, in combination with low educational attainment and anemia. In women, six sarcopenia risk pathways were identified based on age, BMI, AMDR for protein, high density lipoprotein-cholesterol, triglycerides, and living status. The strongest predictor of sarcopenia risk in women was age ≥ 74 years combined with low BMI. Conclusion: Sarcopenia risk factors and pathways differed substantially by sex among older adults. These findings suggest that sex-specific screening and targeted prevention strategies may be effective in reducing sarcopenia risk in older adults.

Purpose: Hereditary spastic paraplegia (HSP) refers to a group of genetic neurodegenerative diseases marked by gradually worsening spasticity and hyperreflexia in the lower extremities. This study aimed to describe the clinical and genetic characteristics of Korean patients with spastic paraplegia. Materials and Methods: We retrospectively reviewed medical records of 69 patients with spastic paraplegia from 54 unrelated families between 2002 and 2024. Genetic, clinical, electrophysiological, and radiological features were comprehensively analyzed. Results: Causative genes were identified in 34 (63%) of 54 unrelated families; SPAST, detected in 26 families, was the most prevalent. Seven novel pathogenic variants were identified. Clinically, the median age of symptom onset was 25 years [14.0–37.0]. Out of 69 patients with spastic paraplegia, 51 (74%) presented with the pure form of spastic paraplegia, which included all patients with SPG4. Spastic gait was a universal feature in all patients. Urinary dysfunction was present in 42 (61%) patients. Additional neurologic manifestations included peripheral neuropathy 9 (13%), cognitive impairment 5 (7%), upper limb weakness 4 (6%), dysarthria 4 (6%), dysphagia 3 (4%), ataxia 3 (4%), and scoliosis 1 (3%). Brain MRI findings demonstrated a thin corpus callosum in two patients with SPG11; all patients with SPG4 had normal findings. Spine MRI revealed spinal cord atrophy in 16 (27%) patients, including 6 (21%) patients with SPG4. Conclusion The study comprehensively reviewed genetic and clinical spectra of spastic paraplegia in Korean patients, emphasizing the predominance of SPAST as the causative gene and underscoring the genetic and phenotypic heterogeneity of spastic paraplegia.

Purpose: Due to chronic toxicity, tacrolimus-sparing is an important issue in kidney transplant recipients (KTRs). Several studies have shown that bisphosphonate use is associated with favorable graft outcomes in KTRs. We investigated whether the association between tacrolimus trough levels (TTLs) and graft outcomes differed according to bisphosphonate use in KTRs. Materials and Methods: We conducted a retrospective study encompassing 1441 KTRs who were administered tacrolimus-based immunosuppressants. The primary exposure was a time-dependent cross-product of TTLs (low TTLs vs. normal-high TTLs with a reference of 6 ng/mL) and bisphosphonate use. Two primary outcomes were evaluated: overall graft loss (death or conversion to kidney replacement) and an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m 2 . Results: During the median follow-up of 6.1 (3.4–9.7) years, overall graft loss occurred in 157 (10.9%) patients. Cox regression revealed that normal-high TTLs without bisphosphonate use were associated with a reduced risk of overall graft loss [adjusted hazard ratio (aHR), 0.65; 95% confidence interval (CI), 0.45–0.95] compared to low TTLs without bisphosphonate use. The use of bisphosphonate in conjunction with normal-high TTLs correlated with an even lower risk of overall graft loss (aHR, 0.25; 95% CI, 0.08–0.80) compared with low TTLs without bisphosphonate use. In patients with low TTLs, bisphosphonate use was associated with a reduced risk of overall graft loss compared with non-use (aHR, 0.20; 95% CI, 0.09–0.43). Similar trends were observed in the eGFR outcome. Conclusion The use of bisphosphonate was associated with favorable graft outcomes, even with low TTLs. Incorporating bisphosphonate into a conventional immunosuppressant regimen may potentially reduce tacrolimus requirement.

Purpose: Based on the KEYNOTE-522 study, neoadjuvant pembrolizumab plus chemotherapy has become the standard treatment for early-stage triple-negative breast cancer (TNBC).This study evaluated the real-world efficacy, safety, and predictors of pathologic complete response (pCR) in Korean patients. Methods: We conducted a retrospective cohort study of 174 patients with early-stage TNBC who received the KEYNOTE-522 regimen (neoadjuvant pembrolizumab plus paclitaxel and carboplatin, followed by doxorubicin and cyclophosphamide) at a tertiary cancer center between August 2022 and July 2024. We assessed the primary endpoints, including pCR rate and event-free survival (EFS). We performed univariable and multivariable logistic regression analyses to identify independent predictors of pCR. Results: The median patient age was 50 years (range, 24–74 years). The clinical stages were II and III in 79.3% and 20.1% of patients, respectively, and 10.9% had clinical N3 disease. The overall pCR rate was 62.1%, and the N3 subgroup had a pCR rate of 47.4%. On multivariable analysis, high baseline Ki-67 expression (≥ median, 75%) was significantly associated with pCR (odds ratio, 2.84; 95% confidence interval, 1.45 to 5.66; p = 0.002). At a median followup of 18.4 months, the 12-month EFS rate was 97.4%, with significantly superior outcomes observed in patients who achieved pCR compared with those who did not achieve pCR (100% vs. 93.1%, p = 0.007). The treatment completion rate was 92.0%, and immune-related adverse events occurred in 13.8% of patients. Conclusion In this real-world analysis of one of the largest Asian cohorts of patients with earlystage TNBC treated with neoadjuvant pembrolizumab, the KEYNOTE-522 regimen demonstrated substantial efficacy and manageable toxicity, consistent with the original trial findings.

Background: Left bundle branch block (LBBB) significantly increases the risk of left ventricular systolic dysfunction (LVSD) due to cardiac dyssynchrony. Although artificial intelligence–enabled electrocardiography (AI-ECG) mod‑ els show promise in detecting LVSD, their performance in LBBB patients remains underexplored. We hypothesized that an AI-ECG model clinically validated for detecting LVSD would accurately detect LVSD and predict future clinical outcomes in LBBB patients. Methods: In this retrospective multicenter study, 5,689 expert-validated LBBB ECGs collected from 2,813 patients between 2016 and 2024 were analyzed using a previously developed and validated AI-ECG model. LVSD was defined as an ejection fraction of ≤ 40%. Model performance was assessed using the area under the receiver operating char‑ acteristic curve (AUROC), the area under the precision-recall curve (AUPRC), sensitivity, and specificity. Patients were stratified into high- and low-risk groups based on a threshold that achieved 90% sensitivity. A Kaplan–Meier analysis was used to compare clinical outcomes. Results: Among the 2,813 LBBB patients (mean age, 70.7 years; male sex, 43.7%), hypertension and a history of heart failure were common. The AiTiALVSD model showed strong diagnostic performance for LVSD (AUROC, 0.930 [95% CI, 0.924–0.937]; AUPRC, 0.913 [95% CI, 0.902–0.923]; sensitivity, 0.979; specificity, 0.473). During the mean follow-up of 4.1 years, high-risk patients had significantly higher hazards than low-risk patients for all-cause mortality (adjusted hazard ratio [HR], 1.87; 95% CI, 1.53–2.28), implantable cardioverter defibrillator/cardiac resynchronization therapy implantation (adjusted HR, 15.2; 95% CI, 7.51–30.77), and cardiovascular hospitalization (adjusted HR, 1.11; 95% CI, 0.96–1.28). Conclusions AiTiALVSD effectively detects LVSD and stratifies long-term cardiovascular risk in LBBB patients, support‑ ing its clinical utility for early detection and patient management.

Objective: This study compared clinical and cosmetic outcomes of cranioplasty using customized three-dimensional (3-D) printed implants versus autologous bone in patients with aneurysmal subarachnoid hemorrhage (aSAH) after decompressive craniectomy (DC). Methods: We retrospectively reviewed 50 patients who underwent cranioplasty after DC for aSAH between July 2018 and December 2023. Patients were divided into the three-dimensional cranioplasty(3-DC, n=26) and autologous bone cranioplasty (AC, n=24) groups. Demographics, aneurysm characteristics, surgical parameters, morphometric analysis of defect coverage, complications, and functional outcomes assessed by the modified Rankin Scale (mRS) were compared. Results: A total of 54 hemispheres underwent cranioplasty. Compared with AC, the 3-DC group had larger defects but achieved higher coverage (96.7% vs. 93.4%, p=0.044) and smaller residual defects (338.7±274.2 mm² vs. 528.5±331.3 mm², p=0.049). Complication rates were lower in 3-DC (9 cases) than AC (15 cases, p=0.0994). Wound dehiscence and fluid collection were more frequent with 3-DC, while bone flap resorption and epidural abscess occurred only with AC. Revision surgery was required in six patients, five initially treated with autologous bone. Neurological outcomes (mRS) were maintained or improved in both groups. Conclusions In aSAH patients undergoing cranioplasty after DC, customized 3-D printed implants achieved significantly better anatomical restoration and showed a numerical trend toward fewer complications compared with autologous bone. While AC remains feasible, its risks of resorption and infection often necessitate revision. 3-D printed implants may be considered a reasonable alternative, particularly in aSAH patients at higher risk of complications.

Background/Aims: The benefits of adjuvant therapy after curative resection (CR) have been demonstrated for bile duct cancer with lymph node (LN) metastasis. However, the putative benefits of adjuvant treatment for bile duct cancer without LN metastasis remain controversial.We aimed to identify recurrence risk factors for distal bile duct cancer (DBC) without LN metastasis following CR and high-risk groups that may benefit from adjuvant treatment. Methods: We retrospectively analyzed recurrence-related factors of patients who underwent surgical resection for DBC at Yonsei University Severance Hospital from January 2010 to June 2019. Results: Of 380 DBC cases receiving CR, 248 (62.8%) were pathologically confirmed as free from LN metastasis. The recurrence rates of all cases and LN metastasis-free cases were similar at 52.4% and 46.8%, respectively. Further, distant metastasis and local recurrence were about equally frequent. Involvement of adjacent organs, the presence of an R1 resection margin (cancer cells present microscopically), lymphovascular invasion (LVI), and perineural invasion (PNI) were identified as risk factors for recurrence (R1 margin OR: 1.642, 95% CI: 1.045–2.578, p = 0.031; LVI OR: 2.049, 95% CI: 1.347–3.115, p = 0.001; PNI OR: 1.901, 95% CI: 1.170–3.088, p = 0.009). Overall survival was also significantly reduced in patients with R1 resection margins (p = 0.018), LVI (p < 0.001), or PNI (p = 0.002). Conclusions The overall risk of LN-negative DBC recurrence remains high after CR. Aggressive systemic adjuvant treatment and active surveillance are required for patients with R1 resection margins, LVI, or PNI.