1.Artificial intelligence-based personalized oncological outcome prediction model for upper urinary tract urothelial carcinoma after radical nephroureterectomy: A development and multicenter validation
Hyun Young LEE ; Hwanik KIM ; Bumjin LIM ; Dalsan YOU ; Cheryn SONG ; In Gab JEONG ; Jun Hyuk HONG ; Bumsik HONG ; Hanjong AHN ; Seung-hwan JEONG ; Ja Hyeon KU ; Jungyo SUH
Investigative and Clinical Urology 2026;67(1):15-23
Purpose:
To develop and validate an artificial intelligence (AI)-based personalized outcome prediction model for upper-urinary tract urothelial carcinoma patients undergoing radical nephroureterectomy.
Materials and Methods:
Data from patients who underwent radical nephroureterectomy between 2010 and 2020 across three hospitals were retrospectively analyzed. A model was developed using one tertiary center’s data and externally validated with data from two other hospitals. An AI model using XGBoost as risk estimator and bootstrapped Weibull Accelerated Failure Time model for 10-year survival probability was employed. Hyperparameter tuning used Optuna method. Model efficacy was assessed using concordance index, average Brier score, D-calibration, and six-month interval time-dependent area under the curve (AUC).
Results:
Of 1,039 patients, 627 qualified after excluding 50 with neoadjuvant chemotherapy. Model development used 564 patients (507 training, 57 test) with 9:1 stratified random split, plus 63 for internal validation and 362 for external validation. Significant parameters included preoperative glomerular filtration rate (p<0.001), hydroureteronephrosis (p=0.013), pathological N stage (p<0.001), concurrent carcinoma in situ (p<0.001), disease progression (p<0.001), and survival rate (p<0.001). Disease-free survival (DFS) model’s concordance index: internal validation 0.789, external validations 0.734 and 0.771. Overall survival (OS) model’s concordance index: internal validation 0.819, external validations 0.780 and 0.771. Mean time-dependent AUC was 0.66–0.77 for DFS and 0.67–0.80 for OS during 10-year periods.
Conclusions
AI-based model effectively predicts disease-free and OS outcomes for upper-urinary tract urothelial carcinoma patients with post-radical nephroureterectomy, showcasing robust performance across multicenter settings.
2.Clinical Outcome Prediction by High-Resolution Computed Tomography and Echocardiography Assessment of Pulmonary Hypertension in Patients with Bronchiectasis
Inhan LEE ; Joon-Sung JOH ; Ji Yeon LEE ; Joohae KIM ; Sooim SIN ; Hyeon-Kyoung KOO ; Ina JEONG
Tuberculosis and Respiratory Diseases 2026;89(2):297-305
Background:
To evaluate the association between pulmonary hypertension and hospital admission rates in patients with bronchiectasis.
Methods:
We retrospectively analyzed data from 130 bronchiectasis patients at the National Medical Center, Korea (November 2012 to October 2022). Pulmonary hypertension was evaluated using high-resolution computed tomography (CT) and echocardiography. Patients were categorized into two groups based on the diameter of the main pulmonary artery (mPA). Logistic regression analysis was performed to identify risk factors associated with hospitalization.
Results:
Forty patients had suspected pulmonary hypertension on echocardiography. A higher percentage of patients with mPA diameter >29 mm (n=61) had a history of previous exacerbations, elevated echocardiographic parameters related to pulmonary hypertension, and reduced lung function, compared to those with mPA diameter ≤29 mm (n=69). In univariate analysis, the hospitalization group showed increased mPA diameter; pulmonary artery to aorta ratio; involvement of lung lobes, cavities, and nodules; and increased systolic pulmonary artery pressure and peak tricuspid regurgitation velocity. In multivariate analysis, mPA diameter >29 mm (adjusted odds ratio [OR], 2.47; 95% confidence interval [CI], 1.14 to 5.32) and the involvement of more than two lobes (adjusted OR, 2.57; 95% CI, 1.14 to 5.77) were significant risk factors for hospitalization.
Conclusion
The CT parameters demonstrated comparable accuracy to models that incorporated echocardiographic data to predict hospitalization in bronchiectasis patients.
3.Association between cardiovascular health measured by Life’s Essential 8 and depressive symptoms
Jeong Hyun AHN ; Hyejin KIM ; Hyeon Chang KIM ; Hokyou LEE ; Younga Heather LEE ; Donald M. LLOYD-JONES ; Sun Jae JUNG
Epidemiology and Health 2026;48(1):e2026013-
OBJECTIVES:
Poor cardiovascular health (CVH) and the high prevalence of depressive symptoms represent significant public health concerns, underscoring the importance of examining their association. This study aimed to investigate the association between CVH, as defined by the American Heart Association’s 2022 Life’s Essential 8 (LE8) framework, and depressive symptoms.
METHODS:
This study used data from the 2014, 2016, 2018, and 2020 Korea National Health and Nutrition Examination Survey. Overall CVH, measured using LE8, was categorized into 3 groups: low score (0–<50), moderate score (50–<80), and high score (80–100). LE8 comprises 2 subdomains: health behaviors and health factors. Depressive symptoms were defined as a total score ≥10 on the Patient Health Questionnaire-9. Multiple logistic regression analyses were performed, adjusting for sex, age, socioeconomic status, and current drinking status.
RESULTS:
Among 17,294 adults, 257 male and 681 female reported significant depressive symptoms. Compared with individuals in the low LE8 category (reference), the odds ratio (OR) for depressive symptoms was 0.29 (95% confidence interval [CI], 0.21 to 0.40) for those in the high LE8 category. The OR for depressive symptoms was 0.39 (95% CI, 0.29 to 0.53) for individuals with a high health behavior score compared with those with a low health behavior score. In contrast, the health factor score was not significantly associated with depressive symptoms.
CONCLUSIONS
These findings suggest that overall CVH, particularly the health behavior subdomain, was associated with lower odds of depressive symptoms. Prospective longitudinal studies are warranted to validate these findings and clarify the directionality of the observed associations.
4.Segmentation-Based Landmark Localization in Cerebral Magnetic Resonance Angiography Using Landmark Subsets
Yura JEONG ; Daehyun KWON ; Se-On KIM ; Ga-Hyeon KIM ; Min-Seo PARK ; Yoon-Chul KIM
Investigative Magnetic Resonance Imaging 2026;30(1):11-19
Purpose:
The accurate localization of bifurcation points in the brain near the circle of Willis is essential for labeling cerebral arteries and detecting potential aneurysms. Studies on the development of segmentation-based landmark localization methods for cerebral angiography are lacking. This study aimed to develop and validate a method for localizing anatomical landmarks using a three-dimensional (3D) encoder-decoder deep convolutional neural network architecture.
Materials and Methods:
Time-of-flight magnetic resonance angiography (MRA) images of 224 subjects obtained from publicly available datasets were used. Ten anatomical landmark points were annotated, and four different landmark subset configurations were trained and validated. For each configuration, 3D U-Net-based models were developed using the MRA images and their corresponding annotated landmarks. The deep learning prediction results were evaluated in terms of landmark localization errors.
Results:
Among the four configurations, the configuration with five landmark subsets produced the smallest landmark localization errors in the test dataset. Post-processing of the U-Net-predicted segmentation masks further reduced the mean localization errors across all landmark points for the configuration with five subsets.
Conclusion
The proposed landmark localization method effectively identified major anatomical landmarks around the circle of Willis and showed the potential to automate segmental analyses of intracranial arterial tortuosity.
5.National Trends in the Prevalence of Suicide Attempts Among Adolescents by Self-Perceived Weight, 2005–2023: A Nationwide Representative Study in South Korea
Jinyoung JEONG ; Hyunjee KIM ; Hyesu JO ; Hyeon Jin KIM ; Jaeyu PARK ; Jaehyeong CHO ; Jiyoung HWANG ; Seoyoung PARK ; Damiano PIZZOL ; Lee SMITH ; Sang Youl RHEE ; Selin WOO ; Dong Keon YON
Psychiatry Investigation 2026;23(1):48-62
Objective:
Suicide is a leading cause of death among adolescents, and despite the need to distinguish between suicidal consideration and suicide attempts, research focused on suicide attempts remains insufficient. Therefore, this study aims to investigate the influence of self-perceived weight on suicide attempts.
Methods:
This study utilized data from the Korea Youth Risk Behavior Web-based Survey for its analysis from 2005 to 2023, including a total of 1,156,728 participants. This study utilized various analytical methods to examine the influence of self-perceived weight on suicide attempts. We estimated weighted prevalence and used linear regression to assess temporal trend β coefficients and their differences (βdiff) with 95% confidence intervals (CIs), and survey-weighted logistic regression to estimate weighted odds ratios (wORs) and 95% CIs for the association between self-perceived weight and suicide attempts.
Results:
A comparison of suicide attempts based on self-perceived weight suggested that individuals who perceived themselves as overweight (weighted prevalence, 3.97% [95% CI, 3.89 to 4.04]) had the highest rate of suicide attempts, followed by those who perceived themselves as underweight (3.36% [95% CI, 3.28 to 3.44]), while those who perceived themselves as having a normal weight (3.20% [95% CI, 3.14 to 3.27]) had the lowest rate. Additionally, females (underweight: 4.47% [95% CI, 4.32 to 4.62]; normal weight: 3.91% [95% CI, 3.81 to 4.01]; overweight: 5.23% [5.11 to 5.35]) experienced more suicide attempts than males (underweight: 2.73% [95% CI, 2.65 to 2.82]; normal weight: 2.43% [95% CI, 2.35 to 2.51]; overweight: 2.60% [95% CI, 2.52 to 2.69]).
Conclusion
Findings from the present study suggest that self-perceived weight was associated with suicide attempts and interaction analyses indicated a potential sex-based difference in the impact of body image distortion. Therefore, this study suggests the introduction of programs and campaigns aimed at correcting distorted self-perceived weight.
6.Clinical Outcomes Based on the Corneal Limbus–Scleral Tunnel Distance in Flanged Intrascleral Intraocular Lens Fixation
Dong Hyeon KIM ; Yu Min KIM ; Seong Yong JEONG ; Yong Koo KANG ; Dong Ho PARK ; Jae Rock DO
Journal of the Korean Ophthalmological Society 2026;67(4):103-109
Purpose:
To compare the anatomical and clinical outcomes based on the distance from the corneal limbus to the scleral tunnel in flanged intrascleral intraocular lens (IOL) fixation.
Methods:
We retrospectively analyzed the medical records of patients who underwent scleral fixation of flanged IOLs. Group 1 (54 eyes) had a distance of 2.1 mm from the corneal limbus to the scleral tunnel, and Group 2 (48 eyes) had a distance of 2.8 mm. We evaluated the best corrected visual acuity (BCVA), postoperative complications, IOL tilt and decentration, refractive prediction error (RPE), effective lens position, and iris-IOL distance.
Results:
The BCVA, postoperative complications, IOL tilt, and IOL decentration did not differ between the two groups (p > 0.05). The RPE showed a hyperopic shift in Group 1 and a myopic shift in Group 2 (Group 1: +0.24 ± 0.68 D, Group 2: -0.03 ± 0.43 D, p = 0.03). The iris-IOL distance was statistically longer in Group 1 compared to Group 2 (Group 1: 1.02 ± 0.40 mm, Group 2: 0.57 ± 0.32 mm, p = 0.02). The incidence of pupillary optic capture was significantly higher in Group 2 compared to Group 1 (Group 1; 0%, Group 2; 8.3%, p = 0.03).
Conclusions
It should be considered that a shorter distance from the corneal limbus to the scleral tunnel results in a postoperative hyperopic shift and reduces the incidence of pupillary optic capture when performing flanged intrascleral IOLs fixation.
7.Current status of hepatitis C treatment and its barriers in Jeonbuk, Republic of Korea
Ji Hyeon KANG ; You Jeong MOON ; Ung-Gyu KIM ; Jung-Im PARK ; Chang Hun LEE ; In Hee KIM ; Ju-Hyung LEE ; Jin GWACK
Osong Public Health and Research Perspectives 2026;17(2):188-192
Objectives:
In alignment with the World Health Organization’s goal of eliminating hepatitis C, this study assessed the current treatment status and reasons for non-treatment among patients with hepatitis C in Jeonbuk State, Republic of Korea, to inform strategies for improving care engagement.
Methods:
Among 311 individuals diagnosed with hepatitis C and reported through the NationalNotifiable Infectious Disease Surveillance system between January 2023 and June 2024, 208 patients were surveyed after excluding those who had died or could not be contacted.Statistical analyses included the chi-square test, the Cochran-Armitage test for trend, and logistic regression.
Results:
Overall, 116 participants (55.8%) reported having received antiviral therapy. Among the 92 untreated individuals, the most common reason for non-treatment was the absence of symptoms (n = 23; 25.0%), followed by the burden of drug costs (n = 21; 22.8%).
Conclusion
These findings highlight suboptimal treatment uptake and key barriers that may hinder progress toward hepatitis C elimination. Expanding screening and strengthening linkage-to-care strategies, while addressing financial barriers, will be essential to achievingnational elimination targets.
8.Gastrointestinal Stromal Tumor:History, Molecular Subtypes, and Risk Stratification
In Hye SONG ; Soomin AHN ; Hyung-Don KIM ; Jeong-Hyeon JO ; Jinho SHIN ; Min-Hee RYU ; Young Soo PARK
Journal of Gastric Cancer 2026;26(2):202-218
The gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Between the 1990s and early 2000s, GIST was identified as a tumor characterized by KIT or PDGFRA mutations, resulting in imatinib being established as an effective targeted therapy. However, with advances in molecular diagnostics, approximately 10%–15% of GISTs have been reported to harbor alternative mutations, such as those in the succinate dehydrogenase subunit genes and BRAF, leading to the development of additional targeted therapies. GISTs exhibit a wide spectrum of clinical behaviors, ranging from indolent to highly aggressive, prompting the development of diverse risk classification systems. However, multiple systems remain in use, leading to inconsistent pathologic reports. Moreover, the mitotic counting method—a key factor in risk stratification—has become a major source of confusion among pathologists owing to the adoption of digital pathology and discrepancies between updated international guidelines and outdated reimbursement requirements. These inconsistencies have hindered pathologic reporting and communication between pathologists and clinicians. This review comprehensively overviews the historical background, molecular subtypes, and risk classification systems of GIST, focusing on evolving issues in mitotic rate evaluation and the application of risk classification systems in clinical practice.
9.An Analysis of Judicial Precedents on Medical Practice in Criminal Litigation in Obstetrics and Gynecology
Jeong Hyeon LEE ; Jun Won PARK ; Joon Cheol PARK ; Dong Ja KIM
Korean Journal of Medical Ethics 2026;29(1):31-47
This study analyzed 22 criminal cases involving obstetricians and gynecologists to identify legal trends and propose measures to reduce the legal burden on medical professionals while maintaining stable healthcare services. The cases were retrieved from the Supreme Court of Korea Judicial Information Disclosure Portal using keywords such as “obstetrics,” “gynecology,” “expectant mother,” “fetus,” “neonate,” “delivery,” “uterus,” and “placenta.” The cases were classified into two categories:medical malpractice (16 cases, 72.7%) and abortion and bioethics (6 cases, 27.3%). Guilty verdicts were issued in 8 cases (36.4%), whereas 14 cases (63.6%) resulted in acquittal. The qualitative analysis showed that courts consistently protected physicians’ clinical discretion in unpredictable and unavoidable situations, such as amniotic fluid embolism and uterine atony, provided that standard medical protocols were followed. Procedural appropriateness, rather than the perfection of clinical outcomes, appeared to be the primary basis for judicial protection. Although the judiciary acknowledges the inherent limitations of medical practice and tends to protect physicians when established guidelines are followed, the high frequency of criminal prosecution remains a substantial burden on healthcare providers and may threaten the sustainability of obstetric care.
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.

Result Analysis
Print
Save
E-mail