Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Background: Rapid pathogen identification and antibiotic-susceptibility tests (ASTs) are important for treating bloodstream infections. We compared the performance of the QMAC-dRAST and BD Phoenix M50 direct AST (dPhoenix) systems using bacterial pellets prepared from positive blood culture broth and evaluated their impact on treatment modification. Methods: Direct AST results for 106 Enterobacterales isolates were retrospectively reviewed. Conventional broth microdilution was used to calculate categorical agreement (CA), very major error (VME), major error (ME), and minor error (mE). For isolates showing high VMEs in both methods, supplementary tests were performed. Clinical impact was evaluated by calculating the time required to obtain AST results (time-to-result) and observing changes in antibiotics prescribed after performing ASTs. Results: Both systems showed acceptable overall CA, VME, ME, and mE values (QMACdRAST: 93.6%, 1.6%, 0.9%, and 5.3%, respectively; dPhoenix: 93.1%, 0.9%, 0.6%, and 6.2%, respectively). Piperacillin–tazobactam showed high VMEs with QMAC-dRAST (4/20, 20.0%) and dPhoenix (3/20, 15.0%). Colony AST on 13 isolates revealed that QMACdRAST testing yielded lower minimal inhibitory concentrations (MICs) for piperacillin–tazobactam with three isolates, whereas dPhoenix testing yielded higher MICs with two isolates and lower MICs with two isolates. The average time-to-result was 20.8 hr and 30.1 hr for QMAC-dRAST and dPhoenix, respectively (P < 0.001). After AST, the number of optimal treatments increased from 43 (46.7%) to 72 (78.3%) (P < 0.001). Conclusions The QMAC-dRAST and dPhoenix systems provided reliable AST results with a short time-to-result. However, we recommend performing complementary tests, such as the disk diffusion test, for piperacillin–tazobactam.

Purpose: Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood. Materials and Methods: We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared. Results: A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes. Conclusions GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.

Legal risks and liability issues in medical practice serve as a primary catalyst for the current collapse of essential healthcare services in Korea. Currently, medical disputes in Korea are disproportionately focused on criminal prosecutions and high-damages civil litigation. This punitive approach fosters a culture of concealment, encourages defensive medicine, and accelerates the exodus of medical professionals from essential fields. Ultimately, this cycle deprives the system of opportunities for improvement and poses a significant threat to patient safety. In contrast, many advanced nations have adopted principles of “Just Culture” and “Safe Space,” prioritizing non-punitive reporting and systemic root-cause analysis over individual retribution. To address these issues, this paper proposes four key strategies: First, the establishment of an independent “Patient Safety Investigation Agency” to objectively investigate incidents and identify systemic flaws. Second, a transition from criminal punishment to licensing board-led management, focusing on re-education and counseling to maintain quality of care. Third, the enactment of “Apology Laws” to ensure that expressions of regret or apologies cannot be used as legal evidence of liability, thereby fostering trust and psychological recovery. Finally, the creation of a “Patient Safety Fund” to provide prompt and sufficient public compensation to victims regardless of proven negligence. In conclusion, it is imperative to shift the paradigm by defining medical accidents as “system failures” rather than individual faults. Strengthening the social safety net will encourage medical professionals to return to essential care and build a sustainable healthcare environment centered on patient safety.

Background: Hair drying is a routine cosmetic practice; however, excessive heat exposure and non-uniform airflow can compromise cuticle integrity, degrade hair sensory properties, and induce scalp discomfort. This study aimed to (i) identify a practical thermal window that minimizes perturbation of hair fiber surface and quantify late-stage thermal amplification during the drying process using percentage-based analysis. Methods: Temperature-dependent hair fiber surface morphology was examined by scanning electron microscopy (SEM) after controlled exposure to 41°C, 60°C, 80°C, and 90°C using virgin and chemically damaged hair. The drying efficacy was assessed using the surface and internal moisture indices under airflow shaping (test) and uniform airflow (control) conditions. Hair fluttering (maximum angular displacement) was evaluated before and after drying under warm-cool alternating (60°C-80°C) versus constant hot airflow (80°C). Results: SEM revealed temperature-dependent cuticle disruption, with markedly greater surface perturbation at 90°C than at 80°C. Infrared thermography demonstrated pronounced late-stage thermal amplification: at 150 seconds, the surface temperature increased by 295% (from 24.2°C to 72.0°C) at 90°C, compared with 207% (from 24.2°C to 50.7°C) at 80°C. Airflow shaping promoted preferential surface moisture removal (–13.6%) while limiting internal dehydration (–9.4%), whereas the control condition exhibited minimal surface drying (–4.6%) but substantial internal moisture loss (–22.2%). Warm-cool modulation increased hair fluttering by +11.0%, whereas constant hot airflow reduced it (–3.7%). Conclusion These findings indicate that spatial and temporal control of heat delivery represents a clinically relevant design strategy beyond the nominal temperature specification in hair-drying devices.

Extracranial carotid artery aneurysms (ECAAs) are rare, and the optimal therapeutic modality for these lesions remains controversial. Surgical resection and covered stents may be limited to selected cases. While the concept of using flow diversion is appealing for large aneurysms, the application of flow diverters in extracranial carotid lesions may face restrictions due to off-label use, reimbursement challenges, and factors related to the devices themselves. We report our experience with multiple overlapping Low-profile Visualized Intraluminal Support (LVIS) stents as a reconstructive option for selected ECAAs. Five patients with large ECAAs were treated with multiple overlapping LVIS stents. The primary goal was parent-artery reconstruction and reduction of intra-aneurysmal flow reduction by increasing local metal coverage across the neck of the aneurysm. Double overlapping LVIS stents were used in 3 cases, whereas triple or more extensive overlapping constructs were used in 2 cases. During a mean radiologic follow-up of 24 months, complete occlusion in 2 cases, partial occlusion in 3 cases, and adjunctive procedures in 3 cases were required, and no major thromboembolic or hemorrhagic complications were documented. Adjunctive or staged treatment was required in 3 cases, including balloon angioplasty, additional LVIS stenting, flow-diverter placement, stent-graft placement, or coil embolization. Multiple overlapping LVIS stenting is a feasible and relatively safe reconstructive option for selected large or clinically significant ECAAs, particularly when primary flow-diverter treatment is constrained by off-label indication or reimbursement issues. However, they have limited standalone efficacy, particularly in large or complex aneurysms, often requiring adjunctive or staged treatment.

Human breast milk (HBM) is an ideal nutritional source for the growth and development of infants. In addition, HBM contains hormones, growth factors, microRNAs and exosomes that perform various physiological functions. This study investigates the immunomodulatory effects of HBM-derived exosomes on myeloid cells and chondrocytes, and implications for juvenile idiopathic arthritis. HBM-derived exosomes were isolated and characterized using nanoparticle track analyzer and Western blotting. The HBM-derived exosomes treatment decreased the expression of inflammatory mediators and proinflammatory cytokines in mouse peritoneal macrophages upon lipopolysaccharide stimulation. Flow cytometry analysis of bone marrow-derived macrophages indicated that exosomes promoted M2 polarization, as evidenced by a decrease in cells expressing CD80 (M1 marker) and a concurrent increase in cells expressing M2 marker CD206. In addition, exosome treatment attenuated the mitogen-activated protein kinase signaling pathway by reducing the phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, and IκB-α, thereby reducing the expression of inducible nitric oxide synthase, cyclooxygenase-2, metalloprotease (MMP)-1, MMP-3, and MMP-13 in SW1353 chondrocytes following IL-1β stimulation. These findings suggest that HBM-derived exosomes promote macrophage polarization toward an anti-inflammatory M2 phenotype and exert significant immunomodulatory effects.

Background: and Purpose The relationship between thrombus histology and long-term stroke patient outcomes remains unexplored. We aimed to determine whether the histological characteristics of thrombi are associated with long-term outcomes in stroke patients and to identify the thrombus features linked to these outcomes. Methods: This retrospective multicenter cohort study included 512 patients with ischemic stroke who underwent endovascular thrombectomy between July 2017 and July 2023. Patients were followed up for long-term major adverse cardiovascular events occurrence. Thrombus histology was assessed using immunohistochemistry, including the proportion of fibrin, red blood cells, and platelets, as well as the distribution patterns categorized as layered, erythrocytic, diffuse platelet, and mixed. Results: During a median follow-up of 38.1 months, 164 patients experienced major adverse cardiovascular events, with an incidence rate of 3.02 per 100 person-years. Major adverse cardiovascular events occurrence was associated with the diffuse platelet pattern and proportion of platelets and red blood cells within the thrombus. After adjusting for confounders, the diffuse platelet pattern independently predicted major adverse cardiovascular events, including mortality and stroke recurrence. Subgroup analysis also demonstrated that the association between the diffuse platelet pattern and major adverse cardiovascular events was consistent across key clinical subgroups based on age (≥65 vs. <65 yr), atrial fibrillation, cancer status, and discharge medications. Conclusions Thrombus histology could provide predictive value for long-term prognosis. In particular, histological distribution patterns may be more important than simple composition in thrombus research, including in the prediction of prognosis.

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: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.