Background: This study was performed to establish a rabbit model for esophageal surgery in the treatment of cervical esophageal diseases. The necessary steps for postoperative treatment and esophageal examination were detailed. Methods: This study aimed to confirm the feasibility of the surgical procedure in rabbits and develop a postoperative management protocol. Six New Zealand White rabbits underwent esophagectomy and end-to-end anastomosis of the cervical esophagus under general anesthesia. Postoperatively, the rabbits were fed a specially formulated therapeutic liquid diet for 3 to 7 days. Recovery was monitored for 8 weeks, after which the rabbits were euthanized. Esophagography and endoscopy were conducted during the first postoperative week to assess healing. Results: Of the six rabbits that underwent surgery, two died from nonsurgical complications within 7 days after the operation. Of the remaining rabbits, two were diagnosed with esophageal stricture via esophagography and underwent endoscopy after the first postoperative week. The final two rabbits completed the 8-week postoperative period without complications. Conclusions Esophageal surgery and postoperative treatment in rabbits require careful attention. We anticipate that this study will provide valuable and practical information for researchers conducting esophageal studies using rabbits.

Idiopathic pulmonary fibrosis (IPF) is characterized by maladaptive epithelial–mesenchymal crosstalk and progressive extracellular matrix accumulation, whereas currently available antifibrotic agents merely decelerate functional decline.This study investigated whether exosomes derived from human mesenchymal stem cells derived from embryonic stem cells (ESC-MSCs) restore epithelial stress responses and attenuate fibrotic remodeling. Human IPF lung transcriptomes were integrated with a bleomycin-induced murine model analyzed by RNA sequencing and protein signaling, together with cigarette smoke extract-induced injury in A549 epithelial cells. ESC-MSCs-derived exosomes exhibited typical morphology and size distribution, enrichment of tetraspanins, and absence of endoplasmic reticulum contamination, consistent with high-purity preparations. Across human IPF and bleomycin-injured lungs, transcriptomic profiling revealed prominent enrichment of extracellular matrix and cytoskeletal gene programs, whereas mitogen-activated protein kinase (MAPK) and Smad families displayed only modest alterations at the mRNA level. In vivo administration of exosomes during the fibrotic remodeling phase, via either intravenous or intratracheal delivery, resulted in improved body weight, reduced lung weight-to-body weight ratios, and decreased collagen deposition and Ashcroft scores. These structural and functional improvements were accompanied by suppression of profibrotic and mesenchymal markers and selective attenuation of activator protein-1 (AP-1) activity. In epithelial injury models, ESC-MSCs-derived exosomes enhanced cell viability, restored redox homeostasis, and constrained stress-induced mesenchymal gene expression and MAPK phosphorylation in both co-treatment and post-treatment settings. Collectively, these data support an epithelial-centered mechanism in which ESC-MSCs-derived exosomes re-establish oxidative balance and selectively restrict AP-1-driven stress signaling, thereby secondarily limiting extracellular matrix accumulation and fibrotic remodeling.

In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

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.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: This study aimed to identify an effective hamstring exercise method that selectively activates the medial and lateral hamstrings. Methods: Five healthy adults were enrolled in this cross-sectional pilot laboratory study. Surface electromyography was recorded from the semitendinosus and biceps femoris of the dominant limb during prone isometric knee flexion at 90°, with resistance applied at 0° (neutral), 45° (resistance applied from lateral to medial), and −45° (resistance applied from medial to lateral) in randomized order. Three 5-second maximal trials per direction were performed with 30-second rest intervals. Isometric knee flexion strength was measured using a Smart KEMA system (Koreatech Co., Ltd.), and the outcomes were descriptively compared. Results: The participants (three females and two males; 32.4±4.5 years) demonstrated the highest mean semitendinosus and biceps femoris activity at 0° (154.7±24.1 μ V and 100.2±25.1 μ V, respectively) and the lowest at 45° (105.3±5.6 μ V and 76.9±4.4 μ V) and −45° (129.3±12.1 μ V and 64.7±19.0 μ V). The medial-to-lateral activity ratio was highest at −45° (2.2±0.6), compared with 0° (1.6±0.3) and 45° (1.4±0.1). Strength was the greatest at 0° (7.5±0.5) compared with 45° (6.4±1.3) and −45° (5.5±1.3). Conclusion In this pilot study, the medial-to-lateral electromyographic ratio tended to be highest when resistance was applied at −45°, suggesting greater medial hamstring recruitment under this condition. These descriptive findings are preliminary and should be confirmed in adequately powered studies. Modifying the direction of resistance may be a feasible strategy to bias medial (−45°) or lateral (45°) hamstring recruitment depending on rehabilitation goals.

Background: The Act on Decisions on Life-Sustaining Treatment (LST) has been implemented in Korea since 2018, yet data on its application in neurocritical care units remain scarce. This study aimed to evaluate the clinical characteristics and outcomes of LST withdrawal or withholding in the neurocritical care unit. Methods: This study was a retrospective analysis conducted at a tertiary university hospital in Busan, South Korea. Among patients admitted to the neurocritical care unit between February 2018 and August 2023, those with documented decisions for LST withdrawal or withholding were enrolled. Demographic and clinical characteristics, underlying and combined conditions, reasons for LST decisions, measures taken, and time from LST withdrawal to death were extracted from medical records. Results: A total of 69 patients were included, with a median age of 67 years, and 38 (55%) were male. Cerebrovascular disease (62%) and traumatic brain injury (22%) were the most common underlying diagnoses. The primary reason for LST decisions was irreversible neurological damage (71%), followed by systemic complications (19%). Mechanical ventilation cessation (91%) and extubation (86%) were most frequently used measures for LST withdrawal. The median time from LST withdrawal to death was 22 minutes. Conclusions Our study demonstrates that LST decisions in the neurocritical care unit predominantly occur among patients with cerebrovascular disease or traumatic brain injury, mostly triggered by neurological deterioration. Most patients died shortly after withdrawal. These findings provide important insight into current LST withdrawal practices in neurocritical care and may assist clinical and ethical decision making in similar settings.

A unified consensus statement on medication-related osteonecrosis of the jaw (MRONJ) has not yet been established among the Asian member countries or regions of the Asian Federation of Osteoporosis Societies (AFOS). This study aimed to develop a consensus on MRONJ in patients with osteoporosis across these countries and regions. In this study, the term “Asia-Pacific” refers specifically to the Asian member countries and regions of AFOS. A structured survey consisting of nine MRONJ-related questions was distributed across 10 countries and regions to assess the level of agreement and summarize regional perspectives. In addition, a manual literature review and voting were conducted to evaluate the current evidence on MRONJ. The key aspects of MRONJ, including definition, staging, diagnosis, pathogenesis, risk factors, management, and prevention, were generally consistent among the AFOS countries and regions. The annual incidence and incidence rate of MRONJ associated with low-dose antiresorptive therapy in patients with osteoporosis ranged from 0.025% to 0.136% and 21 to 283 cases per 100,000 person-years, respectively. However, evidence regarding the benefits of drug discontinuation before dental surgery, such as tooth extraction, remains insufficient. Large-scale, multinational studies across AFOS countries and regions are warranted to determine the incidence of MRONJ better and evaluate the impact of antiresorptive drug discontinuation before dental procedures. These findings may contribute to the devel opment of effective evidence-based strategies for preventing MRONJ in patients with osteoporosis.

Background: s/Aims: Postoperative pancreatic fistulas (POPF) remain a major cause of morbidity and mortality following pancreatoduodenectomy (PD). Pancreatogastrostomy (PG) and pancreatojejunostomy (PJ) are the two most commonly used reconstruction techniques, yet evidence favoring one over the other is inconclusive. This study evaluates postoperative outcomes following open PD at a single institution that transitioned from PG to PJ as the preferred reconstruction method. Methods: This retrospective comparative study included patients who underwent PD between April 2005 and August 2022. Of 757 patients identified, 522 met the inclusion criteria. Propensity score matching (PSM) was performed to adjust for clinically relevant covariates. Primary endpoints were clinically relevant (CR) POPF (grade B/C) and Clavien–Dindo (CD) grade ≥ 3 POPFs. Secondary outcomes included post-pancreatectomy hemorrhage (PPH), delayed gastric emptying (DGE), systemic complications, length of hospital stay, and mortality. Results: Overall, CR-POPF and CD grade ≥ 3 POPFs occurred in 21.3% and 8.0% of patients, respectively. Thirty-day and in-hospital mortality rates were 3.1% and 4.2%. After PSM, 368 patients (184 PG and 184 PJ) were analyzed. Grade B POPFs were more frequent following PJ than PG (24.5% vs. 15.8%, p < 0.001). Although CR-POPF and CD grade ≥ 3 POPFs were numerically higher in the PJ group, differences were not statistically significant. In contrast, DGE, PPH, and in-hospital mortality were significantly higher following PG (37.0% vs. 25.0%, p = 0.025; 16.3% vs. 8.7%, p = 0.025; and 7.6% vs. 2.7%, p = 0.049, respectively). Conclusions PG was associated with a lower incidence of grade B POPFs but higher rates of DGE, PPH, and in-hospital mortality.