Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Background: The effects of propofol, a commonly used intravenous anesthetic, on the breast cancer tumor microenvironment are not well understood. This study examined the influence of propofol on natural killer group 2, member D (NKG2D) ligand expression, matrix metalloproteinase (MMP)-mediated immune evasion, and natural killer (NK) cell-mediated cytotoxicity in breast cancer cells. Methods: We studied three human breast cancer cell lines representing distinct receptor subtypes: MCF-7 (estrogen receptor - and progesterone receptor-positive), MDA-MB-453 (human epidermal growth factor receptor 2-positive), and HCC-70 (triple-negative). Cells were treated with propofol at concentrations of 0 μg/ml (control; C), 4 μg/ml (P4), or 8 μg/ml (P8). Assessments included mRNA and protein expression of NKG2D ligands, NK cell cytotoxicity, protein levels of MMP-1 and MMP-2, and concentrations of soluble NKG2D ligands. Results: In MCF-7 and HCC-70 cell lines, propofol upregulated the mRNA and protein expression of NKG2D ligands in a dose-dependent manner, enhancing NK cell-mediated lysis. In contrast, in MDA-MB-453 cell lines, propofol downregulated the mRNA and protein expression of NKG2D ligands, resulting in diminished NK cell-mediated lysis. Across all receptor subtypes, propofol did not affect the expression of MMP-1 or MMP-2 or the concentration of soluble NKG2D ligands. Conclusions Our results demonstrate that propofol exerts receptor subtype-dependent effects on NK cell-mediated immunosurveillance in breast cancer cell lines, potentially mediated by changes in the transcription of NKG2D ligands rather than by alterations in MMP expression or their proteolytic activity.

Direct-acting antiviral (DAA) therapy has brought a revolution to the management of chronic hepatitis C virus infection, but its role in patients with active hepatocellular carcinoma (HCC) remains controversial. Early observations suggested a high rate of HCC recurrence following DAA treatment, raising concerns about a potential oncogenic effect regarding rapid viral clearance. However, subsequent large-scale cohort studies and meta-analyses have not consistently confirmed this finding, leading to an overall neutral conclusion regarding the impact of DAA on HCC recurrence. International guidelines from organizations such as the American Gastroenterological Association, American Association for the Study of Liver Diseases, European Association for the Study of the Liver, and Korean Association for the Study of the Liver offer conflicting recommendations, underscoring the absence of a universal framework for this patient population. While the available evidence is largely heterogeneous and retrospective, current data indicate that DAA therapy can be safely integrated into HCC management without clear evidence of harm. Oncologic outcomes, particularly overall and recurrence-free survival, are most favorable when DAAs are administered in close proximity to curative procedures or in non-transplant therapeutic settings. In contrast, studies in liver transplant candidates often show a neutral effect on oncologic outcomes after adjusting for confounding variables. These findings underscore the necessity of individualized, multidisciplinary decisions based on tumor biology, hepatic reserve, and treatment intent. Prospective studies and validated biomarkers are essential to establish a more definitive framework for optimizing DAA therapy in this complex clinical context.

Objective: This study aimed to assess the prevalence of drug use-related problems in a Korean community sample and to examine the association between drug use-related problems and health-related quality of life (HRQOL). Methods: Data were collected from 500 community-dwelling adults residing in Jeju, Korea. Drug use-related problems were assessed using the Drug Abuse Screening Test–10, and HRQOL was measured using the 26-item abbreviated version of the World Health Organization Quality of Life instrument. Results: A total of 25 participants (5.0%) reported experiencing drug use–related problems in the previous 12 months.Multivariate analysis revealed that drug use-related problems were significantly associated with lower scores in all HRQOL domains, i.e., physical health, psychological health, social relationships, and environment, even after adjusting for relevant covariates. Conclusion Drug use-related problems were strongly associated with poorer HRQOL. These findings imply that clinicians should pay close attention to HRQOL when evaluating and treating individuals with illicit drug use.

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.

Induced pluripotent stem cells (iPSCs) are a promising cell source for regenerative medicine. Clinical applications require a large number of functional red blood cells (RBCs), making it essential to ensure the proliferation of actively dividing, nucleated erythroblasts derived from iPSCs. Small molecules can enhance the efficiency and frequency of iPSC-derived cell differentiation. Sirtuin 1, a key enzyme in multiple biological processes, has been implicated in enhancing iPSC-derived cell differentiation. However, the specific effects of Sirtuin 1 on erythroblast proliferation from iPSCs remain unclear. Here, we developed a protocol to examine the effects of Sirtuin 1 on erythroblasts after endothelial-to-hematopoietic transition (EHT). We found that Sirtuin 1 activation increased the frequency of CD71＋CD235a＋erythroblasts at the early stage after EHT, suggesting a role for Sirtuin 1 in the proliferation of these specified erythroblasts. These findings reveal that Sirtuin 1 activation benefits erythroblast proliferation and could be considered for translational application in large-scale RBC culture.

Optimal vascular access and effective closure are fundamental for ensuring the safety and success of percutaneous cardiovascular interventions. As procedural complexity has increased, various access and closure devices have been developed to enhance efficacy and minimize complications. Radial artery access is favored for coronary interventions because it is associated with a lower risk of bleeding and fewer access site complications. However, femoral access remains indispensable for large-bore procedures. Large-bore sheaths are required for endovascular treatments of peripheral artery disease and structural heart interventions. Ultrasound-guided arterial and venous access has become essential for minimizing complications, especially with femoral access. Despite significant advances in closure techniques, complications such as retroperitoneal hemorrhage, pseudoaneurysm, and arteriovenous fistula remain challenging and can adversely affect patient outcomes. This review presents state-of-the-art strategies for the prevention and management of vascular access complications in cardiovascular intervention.

Sarcopenia is a major geriatric syndrome characterized by progressive loss of muscle mass and strength, resulting in disability and mortality. This narrative review synthesizes international consensus recommendations and Korean evidence to guide context-specific sarcopenia management strategies. PubMed, Embase, Cochrane Library, and KoreaMed (January 2000–November 2025) were searched, focusing on randomized trials, meta-analyses, systematic reviews, clinical practice guidelines, and large observational studies. Global diagnostic frameworks have evolved from muscle mass-based definitions toward multidimensional models that incorporate muscle strength and physical performance. Exercise and nutrition remain the mainstay treatments, with resistance-based training and adequate protein intake. Currently, pharmacologic options with proven clinical benefit are limited. In Korea, growing evidence supports the effectiveness of community-based sarcopenia interventions, underscoring the need for standardized, integrated delivery models that bridge the fragmented healthcare system and enable sustainable implementation.

Background/Aims: Gastroesophageal reflux disease (GERD) after peroral endoscopic myotomy (POEM) is a significant challenge. Disruption of the lower esophageal sphincter during POEM and dysfunction of the crural diaphragm, which contributes to esophagogastric junction pressure, may lead to GERD after POEM. We aim to identify predictors of GERD after POEM and focus on physiological parameters of esophagogastric junction pressure in patients with achalasia before POEM. Methods: We retrospectively analyzed a prospectively collected database of patients who underwent POEM between July 2016 and August 2023. Ninety-two patients with achalasia who underwent high-resolution manometry and endoscopy before and after POEM were included. Results: Forty-nine (53.3%) patients were diagnosed with GERD. Patient demographics, achalasia subtypes, prior treatments, myotomy length, and myotomy orientation were not associated with GERD after POEM. Loss of inspiratory augmentation before POEM was associated with GERD after POEM (P < 0.05). GERD occurred more frequently in patients with a shorter intra-abdominal lower esophageal sphincter length before POEM. Type III esophagogastric junction morphology in the GERD group (37.1%) was more common than that in the non-GERD group (15.8%). Loss of inspiratory augmentation occurred more frequently in patients with type III esophagogastric junction pressure morphology. Conclusion Loss of inspiratory augmentation may predict GERD after POEM.

The recommendations for carbohydrate intake were revised in the 2025 Korean Dietary Reference Intakes to reflect updated evidence on chronic disease risk and to clarify the interpretation of the Estimated Average Requirement (EAR) and Recommended Nutrient Intake (RNI). These revisions aim to strengthen both the scientific basis and the practical interpretation of carbohydrate intake guidance across the life course of an individual. For individuals aged 1 year and older, the Acceptable Macronutrient Distribution Range for carbohydrates was lowered from 55–65% of total energy to 50–65%. This adjustment reflects accumulating evidence from prospective cohort studies and meta-analyses indicating that very high carbohydrate intake is associated with an increased risk of adverse health outcomes. In contrast, an intake of approximately 50–55% of total energy is associated with the lowest mortality risk. Importantly, this change does not imply a preference for low-carbohydrate diets, as overall dietary quality, including carbohydrate quality, remains a critical consideration. The EAR (100 g/day) and RNI (130 g/day) are derived from estimates of brain glucose utilization and metabolic adaptation and should be interpreted as physiological minimum intake levels rather than population-based intake targets. In addition, life-stage-specific recommendations were updated based on new evidence, including recalculating the Adequate Intake (AI) for infants (55 g/day for 0–5 months and 85 g/day for 6–11 months) and revising the additional requirements during pregnancy (+35 g/day) and lactation (+55 g/day).Because no Tolerable Upper Intake Level (UL) has been established for total carbohydrate intake, excess intake should be managed through dietary adjustments, including limiting added sugars and refined carbohydrates, ensuring adequate fiber intake, and maintaining overall macronutrient balance. Collectively, these revisions provide an updated evidencebased framework for carbohydrate intake guidance for the Korean population.