The gut microbiome is not just a bystander of colorectal carcinogenesis but is an active driver of colorectal cancer (CRC). CRC-associated microbiome contributes in the tumorigenesis through chronic inflammation, formation of toxic metabolite and genotoxins, oncogenic signal activation, immune evasion, and barrier disruption—all reinforcing a tumor microenvironment. In contrast, beneficial microbiome supports the barrier-immune-metabolic axis by maintaining mucosal integrity and balanced immune tone. Despite extensive studies of microbiome-based CRC biomarkers, microbiome-based CRC biomarkers have not been yet ready for routine clinical use due to variation across populations and lack of standardization of key steps such as sampling, analysis, cutoffs, and interpretation. Microbiome-based therapies aim to change the overall intestinal ecosystem rather than simply adding or removing single strains. At present, dietary modulation and prebiotics are considered supportive measures, while probiotics or synbiotics are in preclinical stage. Fecal microbiota transplantation (FMT) still faces important challenges in effectiveness, standardization and safety. By its role in reshaping the tumor–host immune environment, FMT is viewed as a potential option for cancer therapy after further development through well-controlled clinical trials with careful safety monitoring.

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: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.

Background: Fusion genes are major drivers of acute leukemia. Conventional diagnostics are limited in detecting the diverse fusions included in recently updated acute leukemia classifications. We evaluated the fusion detection performance of RNA sequencing (RNAseq) compared with that of conventional diagnostics in patients with acute leukemia. Methods: We retrospectively obtained the data of 101 patients with acute leukemia who underwent conventional diagnostics (i.e., karyotyping, FISH, or multiplex reverse transcription PCR) at diagnosis at Samsung Medical Center, Seoul, Korea, between September 2022 and September 2023. Whole RNA-seq was performed using the Illumina Stranded mRNA Prep kit (Illumina, San Diego, CA, USA). The concordance, sensitivity, and specificity of RNA-seq for fusion gene detection were compared with those of conventional diagnostics. Results: RNA-seq helped identify 52 fusion genes in 51 (50.5%) of 101 patients, with detection rates of 40.7%, 70.3%, 37.5%, and 50% in acute myeloid leukemia, B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia, and mixed-phenotype acute leukemia, respectively. RNA-seq showed 83.3% sensitivity and 80.8% concordance with conventional diagnostics; it missed eight fusions, likely because of low transcript abundance or enhancer hijacking. RNA-seq also helped clarify three previously unspecified rearrangements and detected 12 fusions (21.4%) in 56 cases that tested negative with conventional diagnostics, including four novel (KMT2A::THAP12 , RUNX1::PRPF19 , MLLT10::UBE2L6, and FUS::ZNF362) and three rare (HNRNPH1::ERG, RUNX1::USP42, and ETV6::NCOA2) fusions. Conclusions This was the first study to evaluate the performance of whole RNA-seq in fusion detection in patients with acute leukemia in Korea. Incorporating RNA-seq into diagnostic workflows may facilitate earlier and more precise therapeutic decisions and improve prognostic assessment in patients with acute leukemia.

Purpose: This study aimed to develop and evaluate the effectiveness of the Trauma-nursing Education and Skill Support (TESS) program based on the ADDIE model (Analysis, Design, Development, Implementation, Evaluation model). The program was designed to enhance trauma nurses’ clinical competencies, including trauma-related knowledge, self-efficacy, and problem-solving ability, through the integration of theoretical education and simulation-based practice. Methods: A quasi-experimental study using a non-equivalent control group pretest–posttest design was conducted. Participants included 108 trauma nurses from regional trauma centers, military trauma centers, and emergency care facilities, who were assigned to an experimental group (n=52) or a control group (n=56). The TESS program consisted of a 2-day, 14-hour blended-learning course that included eight lecture sessions and four simulation-based practice stations. Data were collected at baseline, immediately after the intervention, and at 6 months using validated instruments measuring trauma-related knowledge, self-efficacy, and problem-solving ability. Two-way repeated-measures analysis of variance was used for data analysis. Results: The experimental group demonstrated significant improvements in trauma-related knowledge, self-efficacy, and problem-solving ability compared with baseline (all p<.001). These improvements were sustained at 6 months, although trauma-related knowledge scores showed a slight decline compared with immediate posttest levels. Between-group analyses confirmed significant group-by-time interaction effects for all outcomes: trauma-related knowledge (η2=0.12, p<.001), self-efficacy (η2=0.09, p=.002), and problem-solving ability (η2=0.08, p=.003). Conclusion The TESS program effectively enhanced trauma nurses’ trauma-related knowledge, self-efficacy, and problem-solving ability, with effects sustained for up to 6 months. Incorporating blended learning and simulation-based training into standardized trauma nursing education may strengthen clinical competencies and ultimately contribute to improved patient outcomes.

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.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Purpose: This study examined the current status, perceptions, and educational needs of primary care education in medical and nursing schools to provide foundational data that can inform effective curriculum development. Methods: In total, 40 medical and 64 nursing schools were eligible for this study. Data were collected through an online survey using Google Forms, developed by the research team, from November 2024 to January 2025. Frequency analysis and independent t-tests were performed to compare perceptions on primary care education between the two schools types. Borich Needs Assessment and Locus-for-Focus model were used to identify and prioritize educational needs. Results: Responses from 21 medical and 24 nursing schools were analyzed. All medical schools primarily offered education in primary care clinics (100%), whereas most nursing schools offered it in community healthcare institutions (87.5%). Visits and observations were the most common educational methods (>80%). Reports, presentations, and discussions were the most used assessment methods (>60%). Multidisciplinary team-based practicums were limited in both medical (9.5%) and nursing (25.0%) schools. Both groups rated the need to expand primary care education and multidisciplinary team approach highly (>4.4/5). “Longitudinality” and “generalism” were educational priority needs across both groups, whereas other elements showed variations. Conclusion This study identified the shared and distinct aspects of primary care education across schools. The findings highlight the importance of enhancing and tailoring primary care education to each school’s specific context and needs, while fostering interprofessional collaboration to strengthen community-based healthcare.

Background: Despite advancements in laboratory animal facility management, pinworm infections remain a persistent issue in immunodeficient mouse colonies. Rapid diagnosis and treatment are crucial to mitigating potential scientific and economic consequences. Effective control requires both the administration of anthelmintic agents and rigorous environmental decontamination. However, the safety and efficacy of these treatments in genetically modified mouse models remains uncertain.Case presentation Aspiculuris tetraptera infestation was identified in multiple immunodeficient mouse models housed in a laboratory facility. Diagnosis was confirmed through fecal flotation for egg detection and necropsy for adult worm examination in the large intestines. Mice received three subcutaneous ivermectin injections at two-week intervals, coupled with environmental decontamination using ivermectin spray for four consecutive weeks. Following treatment, all colonies tested negative for A. tetraptera without any mortality. Conclusions A combination of subcutaneous ivermectin injection and environmental spray application effectively eradicated A. tetraptera infestation in immunodeficient mouse colonies. The treatment protocol led to the complete elimination of eggs and adult worms, offering a practical strategy for managing pinworm infections in genetically modified mouse models. Limitations include the small sample size, and the lack of a comprehensive evaluation of physiological and metabolic safety in immunodeficient mice. Further validation will be required to confirm the broader applicability of this approach.

Zelkova serrata (Thunb.) Makino is a deciduous tree commonly distributed in East Asia. Several investigations have documented the biological activity of extracts of this species, igniting increased interest in its therapeutic potential. However, the phytochemical constituents accountable for these activities remain largely unexplored. In this study, we focused on the antioxidant potential of the leaves and twigs, utilizing bioactivityguided fractionation combined with LC-QTOF-MS online DPPH screening to systematically identify the active compounds. This approach led to the isolation of eight compounds, three of which (compounds 1, 3, and 7) have not previously been documented in the genus Zelkova. Among the isolates, 4 emerged as the most potent antioxidant, exhibiting significant radical scavenging activity in both DPPH (IC 50 = 13.67 ± 1.21 μM) and ABTS (IC50 = 2.69 ± 0.48 μM) assays, exceeding ascorbic acid (IC 50 = 61.51 ± 10.22 μM) and trolox (IC50 = 8.22 ± 2.16 μM), respectively. Our findings not only enrich the phytochemical profile of Z. serrata but also highlight the effectiveness of LC-MS-DPPH as an effective approach for rapid antioxidant discovery.