1.Current Status and Improvement Strategies for the Resident Training System in South Korea:Focusing on Patient Safety and Sustainable Healthcare
Seung-Won OH ; HaDa RYUOK ; Ilyoung OH ; Jae-Heon KANG ; Eun Jin HA ; Hee Gyung KANG ; Serng Bai PAK ; Junghee AHN ; Mihwa YOO ; Eunyoung CHO ; Juhwan OH
Korean Journal of Family Practice 2026;16(1):48-58
The South Korean resident training system is currently at a critical turning point, facing structural crises characterized by excessive labor-intensive environments and deteriorating quality of education. Since the medical standoff in 2024, the limitations of relying on junior doctors’ labor for hospital operations have become increasingly apparent. This review examines the current status and problems of the resident training system, including long working hours exceeding Organisation for Economic Co-operation and Development (OECD) standards, lack of systematic competency-based education, and worsening regional and essential medical imbalances. By analyzing international cases from the United States, United Kingdom, Japan, and Australia, this article proposes four core strategies for reform: (1) establishing a sustainable working and educational environment through the expansion of hospitalist systems and legalizing physician assistant roles; (2) innovating the curriculum and evaluation systems based on entrustable professional activities and milestones; (3) implementing a network-based training model to bridge the gap between metropolitan and regional healthcare; and (4) securing stable financial support and strengthening governance through the establishment of an independent evaluation body (e.g., K-ACGME). Ultimately, reforming the training system is essential not only for the rights and professional growth of residents but also for ensuring patient safety and the long-term sustainability of the national healthcare system.
2.What Should Be Done Right Now for Better Health System in 10 Years?: Health System Reform Tasks
Juhwan OH ; Sang-il LEE ; Kunhee PARK ; Seung-Won OH ; Junghee AHN ; HaDa RYUOK ; Eun Jin HA ; Seung-yeon CHO ; Sung-ju KIM ; Eunyoung CHO ; Hee Gyung KANG ; Serng Bai PAK ; Eun Kyung EO
Korean Journal of Family Practice 2026;16(1):1-8
South Korea’s current healthcare system stands at a critical crossroads that will determine whether it can progress in a better direction over the next decade. Behind the relatively stable level of population health that has been maintained until now, it has become clear that the deterioration of patient experiences, the risk of collapse in critical emergency medical services, the burnout of healthcare providers, and the crisis in the sustainability of healthcare finances have all accumulated simultaneously. This crisis can no longer be overcome by partial fixes or short-term measures alone. The answer to what needs to change first must begin with a reaffirmation of what the healthcare system should aim for. Ultimately, what needs to be changed now is not an individual policy, but the criteria and priorities through which we view healthcare. The focus must shift from what to provide more of, to questioning what holds greater social value. If such a shift does not begin now, in ten years we won’t face a better healthcare system, but care enmeshed in a deeper crisis. Now is precisely the time to fundamentally define the direction of the healthcare system.
3.Association between Fibrovascular Translucency of Pterygium and Corneal Curvature and Aberrations after Adjustment for Horizontal Invasion Length
Dong Hee HA ; Seung Hyeun LEE ; Kyoung Woo KIM
Korean Journal of Ophthalmology 2026;40(1):45-52
Purpose:
This study aims to determine whether the translucency-based clinical grade of pterygium shows independent relationships with anterior and posterior corneal curvature and anterior wavefront aberrations, with adjustment for horizontal invasion length (HIL) measured by anterior segment (AS) swept-source optical coherence tomography (SS-OCT).
Methods:
This study involved 53 eyes from 51 patients diagnosed with primary nasal pterygium. The clinical grade of the pterygium was evaluated using T grade based on the fibrovascular translucency. AS SS-OCT (Anterion, Heidelberg Engineering) provided HIL (in millimeters), thickness (in micrometers), anterior/posterior keratometry at the 3.0-mm ring, and anterior corneal wavefront metrics within a 6.0-mm zone. The device was also used to evaluate the magnitudes for the individual first-to fourth-order aberrations of the anterior corneal fields. Also, the fourth- to seventh-order root mean square (RMS), RMS lower-order aberration (LoA), and RMS higher-order aberration (HoA) values were collected. For statistical analysis, Spearman rank correlation test and Pearson correlation test were performed, along with partial correlation test adjusted for HIL.
Results:
The mean age of subjects was 59.3 ± 11.4 years, and 51.0% were female. T grade correlated positively with HIL. HIL showed strong associations with anterior simulated keratometry (Sim K) average, anterior Sim K steep, anterior Sim K flat, and anterior corneal astigmatism—but not with posterior corneal parameters. HIL also showed significant correlations with multiple anterior corneal wavefront parameters. After adjustment for HIL, T grade remained independently correlated with anterior Sim K flat, RMS LoA, and defocus; no significant relationships were observed with other Zernike terms or posterior metrics. Additionally, T grade was positively correlated with pterygium thickness.
Conclusions
T grade adds independent, complementary information (associations with flat keratometry, LoA RMS, and defocus) even after controlling for HIL. Incorporating T grade into preoperative assessment may improve estimation of optical burden and surgical prognosis.
4.Secondary Metabolites of Hemerocallis fulva var. kwanso Regel and Their PTP1B Inhibitory Potential
Thi Thanh LE ; Manh Tuan HA ; Trong Trieu TRAN ; Seung Eui MIN ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):76-83
A phytochemical study of the root extract of Hemerocallis fulva var. kwanso Regel resulted in the isolation and structural characterization of four lignans (1‒4), three flavanones (5, 6, and 8), one chalcone (9), and two monoterpenes (7 and 10). Enzyme inhibition assays revealed that two flavanone glucosides (5 and 6) showed significant inhibitory effect against protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 31.38 µM and 51.46 µM, respectively. Further enzyme kinetic studies demonstrated that these two compounds acted as noncompetitive PTP1B inhibitors, with Ki values of 30.88 µM and 50.38 µM, respectively.
5.A New Methoxyflavonoid Rutinoside and PTP1B-Inhibitory Phenolic Compounds from the Water Extract of Areca catechu L.
Manh Tuan HA ; Trong Trieu TRAN ; Thu Huong TRAN ; Seung Eui MIN ; Sang-Jin PARK ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):50-55
Phytochemical investigation of the water extract and alkaloid fraction of Areca catechu L. led to theisolation of one new methoxyflavonoid rutinoside (1), together with eleven known compounds (2−12), five of which (8−12) belong to the pyridine alkaloid class. The structure of the new compound was elucidated through extensive spectroscopic analyses, including 1D and 2D NMR experiments and high-resolution mass spectrometry.Notably, rhamnazin-3-O-rutinoside (2) is reported here for the first time from this species. The isolated compounds were evaluated for their inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) using a p-nitrophenyl phosphate assay. Flavonoids (3 and 4) and stilbene (5) exhibited notable inhibitory activity, with IC50 values of 13.30 ± 0.71, 13.44 ± 0.84, and 8.68 ± 0.12 μM, respectively. In contrast, methoxyflavonoid rutinosides (1 and 2) and pyridine alkaloids (8−12) did not show significant inhibitory activity against PTP1B.These findings provide additional chemical insights into A. catechu and its constituents in relation to PTP1B inhibition.
6.Bioavailability of lutein following short-term consumption of raw vegetables and juice
Seung-Hui CHOI ; Kyoung Yun KIM ; Ha-Rin MOON ; Ha-Yun JEONG ; Min-Jung KANG ; Soomin LEE ; Eunju PARK ; Young-Shick HONG ; Jung-Mi YUN
Nutrition Research and Practice 2026;20(2):253-271
BACKGROUND/OBJECTIVES:
Lutein, a dietary carotenoid, plays a crucial role in protecting eye health as an anti-inflammatory agent and antioxidant. Green leafy vegetables constitute a major source of lutein; however, comparative studies on different consumption methods are limited. Therefore, this study aimed to evaluate the bioavailability of lutein from lutein-rich foods, namely, raw vegetables and raw vegetable juice.
SUBJECTS/METHODS:
In this study, 18 adults were recruited. They were randomly divided into three groups: commercial lutein supplement (LUT, 20 mg), raw vegetable (RV), and raw vegetable juice (RVJ) groups. Blood was collected at 0-, 4-, 6-, 8-, 12-, 24-, and 30-h intervals after the consumption of each test meal. Participants’ serum lutein levels were analyzed using high-performance liquid chromatography (HPLC). Considering lutein’s wellestablished anti-inflammatory properties, changes in inflammatory status were assessed by measuring serum high-sensitivity C-reactive protein (hs-CRP) levels. Furthermore, urinary metabolomic profiling was conducted using 1 H nuclear magnetic resonance spectroscopy to evaluate metabolic alterations.
RESULTS:
After consuming each lutein-rich food, participants’ blood lutein levels were analyzed, and the serum concentration peaked at 12 h (0.37 ± 0.13 μg/mL), 24 h (0.61 ± 0.18 μg/mL), and 30 h (0.42 ± 0.16 μg/mL) after RV, LUT, and RVJ consumption, respectively.Additionally, hs-CRP levels decreased following lutein-rich food consumption. Twelve hours after consumption, hs-CRP levels decreased to 0.81 and 0.83 mg/L in the RV and RVJ groups, respectively. Twenty-four hours after consumption, they further decreased to 0.68 and 0.74 mg/L in the LUT and RVJ groups, respectively. Thirty hours after consumption, a reduction to 0.61 mg/L was observed in the RVJ group. Furthermore, after consuming each luteinrich food, N-acetyl glycoprotein levels decreased at 24 h, reflecting metabolic alterations potentially associated with lutein metabolism.
CONCLUSION
These findings suggest that the short-term consumption of lutein-rich foods, regardless of their type or source, potentially yields health benefits.
7.Real-World Efficacy of Intravesical Gemcitabine for BCG-Unresponsive Non–muscle-Invasive Bladder Cancer
Hye Won LEE ; Eui Hyun JUNG ; Kyung Hwan KIM ; Hong Koo HA ; Jong Jin OH ; Seok Ho KANG ; Seung-hwan JEONG ; Hyeong Dong YUK ; Ji Eun HEO ; Won Sik HAM ; Eu Chang HWANG ; Seung Il JUNG ; Wan SONG ; Bumjin LIM ; Bumsik HONG ; Byung Chang JEONG ; Ho Kyung SEO
Cancer Research and Treatment 2026;58(2):591-602
Purpose:
This study aimed to report the real-world outcomes of intravesical gemcitabine for bacillus Calmette–Guérin (BCG)–unresponsive, high-risk, non–muscle-invasive bladder cancer (HR-NMIBC) in Korean patients who were unable or unwilling to undergo radical cystectomy (RC).
Materials and Methods:
This retrospective study included 131 patients (median age, 69 years; 88.5% men) treated with intravesical gemcitabine for BCG-unresponsive HR-NMIBC at nine centers between May 2019 and April 2022. The primary endpoint was 1-year recurrence-free survival (RFS). The secondary endpoints included factors influencing RFS, progression-free survival (PFS), cystectomy- free survival, cancer-specific survival (CSS), overall survival (OS), and safety. Survival analysis was performed using the Kaplan-Meier method, and risk factors for recurrence were assessed using Cox regression models.
Results:
Patients were followed up for a median duration of 25 months, with carcinoma in situ (CIS) in 41.9% of the patients. The 1-year and 2-year RFS rates were 68% and 42%, while the 1-year and 2-year PFS rates were 87% and 77%, respectively. No significant factors influencing RFS were identified. Seventeen patients underwent RC during a median follow-up of 16 months, with the condition in three patients progressing to muscle-invasive disease on final pathological analysis. The 2-year CSS and OS rates were 98% and 97%, respectively. Intravesical gemcitabine was well-tolerated, with only seven patients (5.3%) unable to complete the full induction course.
Conclusion
Our research highlights the potential of intravesical gemcitabine as a viable bladder-sparing treatment option for BCG-unresponsive HR-NMIBC, providing real-world evidence on its safety, efficacy, and tolerability.
8.Discrepancy between Genetically Predicted and Observed Alcohol Intake and Its Impact on Gastric Cancer Susceptibility
Ga-Eun YIE ; Cheol Min SHIN ; Kyungtaek PARK ; Jinyeon JO ; Ah Ra DO ; Sungkyoung CHOI ; Jung Hun OHN ; Sejoon LEE ; Jeongseon KIM ; Sun Ha JEE ; Seung Joo KANG ; Nayoung KIM ; Sungho WON
Cancer Research and Treatment 2026;58(2):563-572
Purpose:
We aimed to investigate how genetic predisposition to drinking and gastric cancer (GC) modifies the association between alcohol consumption and GC risk in the Korean population.
Materials and Methods:
Polygenic risk scores for GC (PRS-GC) and alcohol consumption (PRS-Alcohol) were formulated using genome-wide association results from BioBank Japan. Validation was performed using Korean cohorts (SNUBH-GENIE cohort), incorporating 8,846 controls and 531 patients with GC. Subsequently, these PRSs were applied to an independent Korean cohort of 67,771 participants, including 313 patients with GC during the follow-up for 14 years (KoGES cohort).
Results:
In KoGES cohort, the influence of alcohol consumption on GC risk was significantly altered by the PRS-GC and exhibited a synergistic interaction effect. PRS-Alcohol itself shows a negative correlation with GC risk. However, when actual alcohol consumption significantly exceeded genetically predicted levels, the risk of alcohol-related GC was notably increased (adjusted hazard ratio, 1.32; 95% confidence interval, 1.01 to 1.72). Heavy drinkers in the high–PRS-GC/low–PRS-Alcohol group had a 2.16 times higher risk of GC than non-to-light drinkers, which was prominent in males.
Conclusion
Korean drinkers with higher PRS-GC who consume alcohol more than genetically predicted levels are susceptible to GC. PRS-GC and PRS-Alcohol may be beneficial for assessing the impact of alcohol consumption on GC risk in Koreans.
9.Gastrointestinal Surgery Status and the Risks of Ischemic Stroke and Safety Outcomes With Direct Oral Anticoagulants Versus Warfarin in Atrial Fibrillation: A Nationwide Population-Based Cohort Study
Jiyeon HA ; Wookjin YANG ; Mi-Sook KIM ; Eung-Joon LEE ; Matthew CHUNG ; Boyeon YANG ; Hyemin JANG ; Jeong-Min KIM ; Keun-Hwa JUNG ; Seung-Hoon LEE
Journal of Stroke 2026;28(2):228-239
Background:
and Purpose Although gastrointestinal (GI) surgery can affect drug efficacy, its impact on oral anticoagulants (OACs) remains unclear. This study investigated the impact of GI surgery on the comparative effectiveness and safety of direct oral anticoagulants (DOACs) versus warfarin in atrial fibrillation (AF).
Methods:
Using a nationwide South Korean claims database, AF patients prescribed OACs between 2015 and 2021 were analyzed. The primary outcome was ischemic stroke, and secondary outcomes were major bleeding, all-cause death, and composite outcome (ischemic stroke, major bleeding, all-cause death). Outcomes were compared by OAC type (DOAC vs. warfarin) and GI surgery status using inverse probability of treatment weighting and a Fine–Gray subdistribution hazard model with time-varying covariates.
Results:
Among 388,214 AF patients (mean age, 71.9 yr; 42.7% male), 6,907 (1.8%) underwent GI surgery. The effect of GI surgery differed between warfarin and DOACs for ischemic stroke (Pint= 0.018), with increased risk for warfarin (adjusted HR [aHR]: 2.32; 95% confidence interval [CI] 1.17–4.62), but not for DOACs (aHR: 0.97 [95% CI 0.77–1.22]) after surgery. Effects of surgery on major bleeding, all-cause death, and composite outcome did not differ. In post–GI surgery setting, DOACs demonstrated lower ischemic stroke risk (aHR: 0.35 [95% CI 0.17–0.72]) and comparable risks for other outcomes. Exploratory analyses by surgery location suggested a more favorable profile of DOACs after upper GI surgery.
Conclusions
In AF patients, GI surgery significantly increased ischemic stroke risk among warfarin users, but not among DOAC users. DOACs showed generally favorable profiles after GI surgery and may remain a reasonable anticoagulant, with potentially more favorable profile after upper GI surgery.
10.A Protocol of Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ)
Geon Ha KIM ; Jung-Min PYUN ; Danbee KANG ; Sung Hoon KANG ; Seong-Ho KOH ; Jae Seung KIM ; So Young MOON ; Won-Jin MOON ; Young Ho PARK ; YongSoo SHIM ; Dong Won YANG ; Young Chul YOUN ; Young Hee JUNG ; Hanna CHO ; Hojin CHOI ; Jae-Sung LIM ; Kee Hyung PARK ; Seong Hye CHOI
Dementia and Neurocognitive Disorders 2026;25(1):25-41
Background:
and Purpose: To assess the long-term effectiveness, safety, and economic viability of recently approved Alzheimer’s disease (AD) therapies, as well as to evaluate the real-world application of novel diagnostics among AD patients with diverse comorbidities, comprehensive real-world data (RWD) analysis is essential. The Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ) endeavors to create a registry of RWD derived from clinical practice on new diagnostic methods and therapeutic agents for AD introduced in Korea since 2021.
Methods:
Participants must fulfill all the following: 1) be at least 19 years old; 2) be actively receiving, scheduled to initiate, or undergoing evaluation for any AD disease-modifying treatment; 3) have completed amyloid positron emission tomography or cerebrospinal fluid AD immunoassay (a positive result is not essential for participation); 4) have a clinical classification of cognitively unimpaired, mild cognitive impairment, or probable AD dementia. Data generated during routine care is segmented into a minimum dataset, extended dataset, and research-only dataset requiring extra consent. Assessments encompass clinical, cognitive, functional, neurobehavioral, neuroimaging, and biomarker evaluations, in addition to systematic monitoring of new AD treatments and their safety.Data are collected and monitored at baseline, at semiannual intervals during the initial 2 years, and then annually up to 2034. To date, 46 medical centers will participate in JOY-ALZ.
Conclusions
JOY-ALZ is expected to promote understanding of the long-term clinical outcomes, safety, and cost-effectiveness of recently introduced diagnostics and treatments for AD, thereby supporting the progress of precision medicine in AD care and diagnosis.

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