1.Structured Integration of an Artificial Intelligence-Based System for the Optical Diagnosis of Colorectal Polyps
Hae Yeon KANG ; Soonwhan KANG ; Goh Eun CHUNG ; Dong Hoon BAEK ; Hong Sub LEE ; Jinbae PARK ; Sun Young YANG ; Seon Hee LIM ; Ji Min CHOI ; Jung KIM ; Jung Ho BAE
Gut and Liver 2026;20(1):86-96
Background/Aims:
Recent advances in computer-aided diagnosis (CADx) systems have demonstrated expert-level accuracy in the optical diagnosis of colorectal polyps. High-confidence (HC) diagnoses have been defined as those made within 3 seconds without hesitation, and these systems have been shown to improve diagnostic accuracy. We aimed to evaluate the performance of endoscopists with varying levels of experience in diagnosing colorectal polyps with the assistance of a new CADx system applying the 3-second rule and without artificial intelligence assistance.
Methods:
In this multicenter ex vivo study, 35 endoscopists assessed 100 polyps (51 adenomas, 39 hyperplastic polyps, 10 sessile serrated lesions) using narrow-band imaging video clips on an online platform. Assessments consisted of individual endoscopist diagnosis and CADx-assisted diagnosis. HC assignments followed the 3-second rule in both phases. Performance metrics included HC accuracy, HC rate, and adherence to the Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) and Simple Optical Diagnosis Accuracy (SODA) thresholds.
Results:
HC diagnostic accuracy improved from 78.3% (95% confidence interval [CI], 76.6% to 80.0%) to 89.8% (95% CI, 88.6% to 90.9%) with CADx assistance (p<0.001). The proportion of HC predictions increased from 64.2% to 75.4% (p<0.001). Novice endoscopists showed marked improvement with CADx (74.1% vs 88.8%; p<0.001). CADx-assisted diagnoses nearly met SODA and PIVI thresholds under the 3-second rule. Additional analysis demonstrated that CADx assistance significantly improved interobserver agreement and ground truth, particularly for novices (κ=0.37 to κ=0.65; p<0.001).
Conclusions
Integrating CADx with the 3-second rule significantly enhances the performance of endoscopists in the optical diagnosis of colorectal polyps, with the greatest benefit observed among novice endoscopists.
2.Establishing Epidemiological Cutoff Values for Helicobacter pylori Strains in Korea: A Model-Based Analysis of Antibiotic Resistance Patterns
Jin Hee NOH ; Jung Mogg KIM ; Hwoon-Yong JUNG ; Ji Yong AHN ; Sun Mi LEE ; Seong Woo JEON ; Yong Hwan KWON ; Jeong Hoon LEE ; Kee Don CHOI ; Eun Jeong GONG
Gut and Liver 2026;20(1):47-58
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.
3.Short-Term Outcomes of Novel Refractive Extended Depth-of-Focus Lens: Stage 1 Epiretinal Membrane vs. Normal Retina
Jiwon CHOI ; Sang Min LEE ; Jae Won CHOI ; Min Ji PARK ; Joo Heon ROH ; Tae Heon LEE ; Sun A KIM ; Su Hey CHAE ; Hee Seong YOON ; Jung Yup KIM
Journal of the Korean Ophthalmological Society 2026;67(2):47-54
Purpose:
We compared short-term clinical outcomes after cataract surgery with implantation of a novel refractive extended depth-of-focus TECNIS PureSee intraocular lens (IOL) between patients with stage 1 epiretinal membrane (ERM)—characterized by a thin membrane over the macula with preserved foveal depression―and those with a normal retina.
Methods:
This retrospective study included 60 eyes of 60 patients who underwent cataract surgery with implantation of the TECNIS PureSee IOL between January 2024 and January 2025: 30 eyes with stage 1 ERM and 30 eyes with a normal retina. Preoperative characteristics, including age, sex distribution, cataract severity, corrected distance visual acuity (CDVA), and higher-order aberrations, were compared between groups, as were IOL power and target refraction. Postoperative outcomes at 1 month―including CDVA, uncorrected distance, intermediate, and near visual acuity, ocular aberrations, and contrast sensitivity―were evaluated.
Results:
There were no significant differences in preoperative characteristics, such as age, sex distribution, cataract grade, CDVA, higher-order aberrations, IOL power, or target refraction between the two groups. At 1 month postoperatively, CDVA, uncorrected distance, intermediate, and near visual acuity, higher-order aberrations, and contrast sensitivity exhibited no significant differences between groups.
Conclusions
In this short-term analysis, the PureSee IOL demonstrated comparable efficacy and safety in cataract patients with stage 1 ERM to those with a normal retina.
4.Development and evaluation of the Trauma-nursing Education and Skill Support program to enhance trauma nursing competencies: a quasi-experimental study
Tae Yeong YANG ; Myung Jin JANG ; Ki Ung KIM ; Min SO ; Mi Na CHOI ; Eun Jung LEE ; Jin Su JO ; Ji Yun LEE ; Kwang Kyun LIM ; Kyoung Mi KIM ; Hae Jun BAEK ; Sun Ho WANG ; Jin Oh CHOI
Journal of Korean Academy of Nursing 2026;56(1):67-80
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.
5.Comparative perioperative outcomes of single-port laparoscopic ArtiSential versus da Vinci SP platform for totally extraperitoneal inguinal hernia repair:a multi-institutional, propensity score-matched analysis in Korea
In Kyeong KIM ; Moonjin KIM ; Ji-Yeon MOON ; Ri Na YOO ; Jumyeong SONG ; Chaedong LIM ; Choon Sik CHUNG ; Gwan Cheol LEE ; Tae Gyu KIM ; Young Sun CHOI ; Dong Geun LEE ; Chul Seung LEE
Journal of Minimally Invasive Surgery 2026;29(1):3-10
Purpose:
This study aimed to compare perioperative and postoperative outcomes of single-port laparoscopic articulated instrument-assisted versus da Vinci SP-assisted totally extraperitoneal (TEP) inguinal hernia repair using a propensity score-matched multi-institutional cohort.
Methods:
Between April 2022 and July 2025, 221 patients underwent TEP unilateral inguinal hernia repair at four institutions. Among them, 33 patients underwent da Vinci SP-assisted repair (Intuitive Surgical) and 188 underwent single-port laparoscopy using the articulated instrument, ArtiSential (LivsMed). Propensity score matching was performed in a 1:1 ratio based on demographic and clinical variables, resulting in 30 matched patients in each group. Perioperative outcomes and postoperative complications were analyzed.
Results:
After matching, baseline characteristics were well balanced between the groups.Operative time was significantly longer in the da Vinci SP group than in the ArtiSential group (median [interquartile range], 82.0 [67.5–105.0] vs. 35.0 [28.5–47.5] minutes; p < 0.001). No open conversions occurred, and conversions to transabdominal preperitoneal repair were rare and comparable. Mesh size selection differed significantly, with smaller meshes more frequently used in the da Vinci SP group (p < 0.001). Postoperative outcomes, including length of hospital stay, overall complication rates, chronic pain, and recurrence, were similar between the groups. No major complications, readmissions, or reoperations were observed.
Conclusion
Articulated instrument-assisted TEP inguinal hernia repair demonstrated a significantly shorter operative time than da Vinci SP-assisted repair, while perioperative safety and postoperative outcomes were comparable.
6.Prevalence of HER2-ultralow breast cancer in South Korea: a multicenter study by reassessment of HER2-zero cases
Min Chong KIM ; Eun Yoon CHO ; Hee Jin LEE ; Ji Shin LEE ; Jee Yeon KIM ; Wan Seop KIM ; Chungyeul KIM ; Sun-Young JUN ; Hye Jeong CHOI ; So Mang LEE ; Ahrong KIM ; Ji-Young KIM ; Jeong Yun SHIM ; Gyungyub GONG ; Young Kyung BAE
Journal of Pathology and Translational Medicine 2026;60(2):184-192
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.
7.Association of Breast Tissue Composition on Preoperative Automated Breast Ultrasound With Accuracy of Cancer Multiplicity Evaluation and Recurrence-Free Survival in Patients With Early-Stage Breast Cancer
Myoung Kyoung KIM ; Haejung KIM ; Sun-Young BAEK ; Eun Young KO ; Boo-Kyung HAN ; Eun Sook KO ; Jeongmin LEE ; Nami CHOI ; Jin CHUNG ; Ji Soo CHOI
Korean Journal of Radiology 2026;27(2):97-110
Objective:
To investigate whether breast tissue composition on preoperative automated breast ultrasound (ABUS) is associated with the accuracy of cancer multiplicity evaluation and postoperative recurrence-free survival (RFS) in patients with early-stage breast cancer.
Materials and Methods:
This retrospective analysis included women with early-stage breast cancer (clinical Tis, T1–2/N0) who underwent ABUS and digital mammography (DM) between October 2019 and April 2021. Tissue composition on ABUS was assessed using the Breast Imaging Reporting and Data System background echotexture (BE) (homogeneous-fat, homogeneous-fibroglandular, or heterogeneous). In a subgroup of patients with mammographically dense breasts, the glandular tissue component (GTC) on ABUS were further stratified into high (moderate or marked) or low (minimal or mild).Multivariable logistic and Cox regression analyses were used to identify factors associated with accurate cancer multiplicity categorization (unifocal, multifocal/multicentric, or bilateral) using ABUS + DM, and with RFS, respectively.
Results:
Among 409 women (mean age ± standard deviation, 50.2 ± 8.7 years), ABUS combined with DM yielded accurate cancer multiplicity categorization in 368 patients (90.0%). Neither BE nor GTC on ABUS affected the accuracy of categorization when ABUS was combined with DM. Over a median postoperative follow-up of 3.5 years, 11 recurrences occurred. Heterogeneous BE on ABUS (hazard ratio [HR] 11.24 [95% confidence interval [CI]: 2.82–44.92]; P = 0.001), BRCA mutation (HR 15.94 [2.47–102.97]; P = 0.004), and pathologic index cancer size (HR per 1-cm increase 1.91 [1.13–3.23];P = 0.02) was independently associated with RFS. In patients with dense breasts, heterogeneous BE (HR 14.17 [95% CI:2.69–74.60]; P = 0.002) and high GTC (HR 10.32 [2.35–45.28]; P = 0.002) on ABUS, BRCA mutation (HR 24.34 [2.75– 215.06]; P = 0.004), and pathologic cancer size (HR per 1-cm increase 2.62 [1.50–4.59]; P = 0.001) was independently associated with RFS.
Conclusion
In patients with early-stage breast cancer, heterogeneous BE and high GTC on preoperative ABUS, along with larger cancer size and BRCA mutation, was associated with worse RFS. However, BE and GTC did not affect cancer multiplicity evaluation when ABUS was used in combination with DM.
8.Eradication of Aspiculuris tetraptera in various immunodeficient mouse models using ivermectin: a case report
Ji-Hun LEE ; Eun-Seon YOO ; Na-Won KIM ; Han-Bi JEONG ; Ah-Reum KANG ; Sun-Min SEO ; Young-Jun PARK ; Byeong-Cheol KANG ; Yang-Kyu CHOI
Laboratory Animal Research 2026;42(1):82-87
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.
9.Pluviatolide Attenuates Type I Hypersensitivity through Regulation of Mast Cell Activation
Seon Young KIM ; Jeong Won PARK ; Juhyun SHIN ; Ji-Ae LEE ; Sun-Hee LEEM ; Min Geun JO ; Min Yeong CHOI ; Wahn Soo CHOI ; Keun Young MIN ; Geunwoong NOH ; Sung-Jin BAE ; Yung Hyun CHOI ; Hyuk Soon KIM
Biomolecules & Therapeutics 2026;34(2):413-422
This study examined the inhibitory effects of pluviatolide, a lignan derived from Podophyllum hexandrum, on mast cell activation and IgE-mediated type I hypersensitivity, focusing on FcεRI-dependent and calcium-mediated pathways. Using bone marrowderived mast cells (BMMCs) and rat basophilic leukemia (RBL)-2H3 cells, we found that pluviatolide significantly decreased β-hexosaminidase release and suppressed the expression and secretion of TNF-α and IL-6 in a concentration-dependent manner, without causing cytotoxicity. While we initially hypothesized that it would selectively modulate antigen-specific FcεRI signaling, pluviatolide also inhibited degranulation induced by calcium ionophore and thapsigargin, indicating its effects extend to receptorindependent, Ca2+-dependent activation mechanisms. Immunoblot analyses revealed decreased phosphorylation of proximal kinases (Lyn, Syk), adaptor proteins (LAT, PLCγ1), MAPKs (ERK1/2, JNK, p38), and NF-κB p65. In a passive cutaneous anaphylaxis (PCA) mouse model, oral administration of pluviatolide significantly reduced Evans blue extravasation and mast cell degranulation in ear tissues. These findings demonstrate that pluviatolide suppresses both early and late-phase mast cell responses through multi-nodal inhibition of activation pathways, highlighting its potential as a therapeutic candidate for both IgE-mediated and non-IgE-mediated allergic disorders.
10.Stress Accelerates Depressive-Like Behaviors through Increase of Notch2 Expression in N141I Mutation Presenilin-2 Transgenic Mice
Seung Sik YOO ; Sun Mi GU ; Kyung Tak NAM ; Jeong Soon CHOI ; Yong Sun LEE ; In Jun YEO ; Ji Eun YU ; Sanghyeon KIM ; Dong Won LEE ; Hyeon Joo HAM ; Ju Young CHANG ; Jaesuk YUN ; Dong Ju SON ; Sang-Bae HAN ; Jin Tae HONG
Biomolecules & Therapeutics 2026;34(3):544-555
Alzheimer’s disease (AD) is characterized by progressive cognitive deterioration and significant depression. However, the mechanisms linking depression to AD pathology remain unclear. Here, we investigated whether Notch2 signaling mediates depressionlike behaviors in presenilin-2 (PS2) N141I mutant mice, an early-onset AD model. PS2 wild-type (WT) and mutant (MT) mice aged 12-15 months were subjected to unpredictable chronic mild stress (UCMS) for 4 weeks, followed by sucrose preference, tail-hanging, and forced swimming tests. Behavioral assessments showed that UCMS exacerbated anhedonia and immobility only in PS2 MT mice. Molecular analysis revealed concomitant increases in plasma corticosterone, hippocampal γ-secretase activity, and Notch2 expression, and elevated total and phosphorylated glucocorticoid receptor levels in PS2 MT-UCMS mice. Gene expression profiling of human hippocampal datasets confirmed upregulation of NOTCH2 in Alzheimer’s disease and depression.Pharmacological inhibition of γ-secretase and Notch signaling with DAPT normalizes depressive behavior, reduces corticosterone release, attenuates GR phosphorylation, and inhibits Notch2 signaling in PS2 MT mice. These findings identify Notch2 as a pivotal mediator linking chronic stress to molecular changes associated with depression and AD, and suggest that targeting Notch2 signaling may provide therapeutic benefits for comorbid mood and neurodegenerative disorders.

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