1.Spatiotemporal Remodeling of Enteric Neural Pathways Underlies ColonicDysmotility Following Spinal Cord Injury in Rats
Min Seob KIM ; Sei KIM ; Se Eun HA ; Hyun Seok CHOI ; Myeong Hwan YU ; Jisong YOU ; Dahyun SEON ; Do Hee LEE ; Min Cheol JOO ; Yong Sung KIM ; Suck Chei CHOI ; Joong Goo KWON ; Kyung Sik PARK ; Hyun Jin KIM ; Seungil RO ; Moon Young LEE
Journal of Neurogastroenterology and Motility 2026;32(1):86-98
Background/Aims:
Spinal cord injury (SCI) frequently impairs defecation, severely affecting the quality of life. This study examines compensatory neural remodeling after SCI, focusing on basal colonic contractility, neural responses to electrical field stimulation, and alterations in excitatory cholinergic and inhibitory nitrergic pathways.
Methods:
Female Sprague–Dawley rats underwent either sham surgery or T10 spinal cord transection and were categorized into 3 groups: sham, 1-week post-SCI (acute), and 4-week post-SCI (chronic). Colonic contractility was assessed in an organ bath using electrical field stimulation in the presence of a nitric oxide synthase inhibitor. Neural protein expression was analyzed by immunofluorescence and Western blotting.
Results:
SCI produced region- and time-dependent impairments in colonic contractility, with distinct alterations in the proximal circular and longitudinal muscles across acute and chronic phases. Neural excitability shifted dynamically, showing enhanced excitatory activity in the proximal longitudinal muscle at 1-week and the distal circular muscle at 4-week post-SCI. Protein analysis revealed increased neuronal nitric oxide synthase in the proximal colon, decreasedsoluble guanylyl cyclase in the distal colon, upregulated muscarinic M3 receptor in the proximal colon, and reduced vaso-active intestinal peptide receptor 1 in both proximal and distal regions.
Conclusion
SCI induces spatiotemporal remodeling of excitatory and inhibitory neural pathways, contributing to colonic dysmotility and revealing potential targets for therapeutic intervention.
2.Quantitative Optical Coherence Tomography Angiography Biomarkers Following a Switch to Brolucizumab in Neovascular Age-Related Macular Degeneration
Seungyeon LEE ; Jaehwan CHOI ; Seung-Young YU ; Kiyoung KIM
Korean Journal of Ophthalmology 2026;40(2):159-168
Purpose:
To evaluate functional and anatomical outcomes, including vessel morphology parameters on swept-source optical coherence tomography angiography (SS-OCTA), in eyes with neovascular age-related macular degeneration (nAMD) switched to brolucizumab.
Methods:
This retrospective study included 37 eyes with nAMD that were switched from other anti–vascular endothelial growth factor (anti-VEGF) agents to intravitreal brolucizumab. Best-corrected visual acuity (BCVA), injection intervals, central subfield thickness (CST), pigment epithelial detachment (PED), and presence of retinal fluid were compared between baseline and 12 months after switch. SS-OCTA images were analyzed to quantify macular neovascularization (MNV) area, vessel density, fractal dimension (FD), and lacunarity.
Results:
Switching to brolucizumab significantly extended injection intervals and reduced CST, PED height and retinal fluid, while maintaining BCVA at 12 months. Quantitative OCTA analysis showed reductions in MNV area and FD following the switch. When compared with the preceding 12 months of other anti-VEGF therapy, FD still showed a significant reduction after brolucizumab treatment (p = 0.019). Intraocular inflammation occurred in one eye and resolved with topical corticosteroids.
Conclusions
Intravitreal brolucizumab demonstrated favorable anatomical improvements and maintained visual outcomes over 12 months. Quantitative OCTA biomarkers, particularly FD, may serve as imaging indicators of disease activity and treatment response in eyes with nAMD undergoing a therapy switch.
3.Quantitative Analysis of Drusen in South Korean Patients: A 36-Month Follow-Up Study
Tae Rim KIM ; Tae Gi KIM ; Jaehwan CHOI ; Seung-Young YU ; Kiyoung KIM
Korean Journal of Ophthalmology 2026;40(1):87-98
Purpose:
This study aimed to quantitatively evaluate longitudinal changes in drusen area and volume over 36 months in South Korean patients and to identify the factors associated with these changes and the development of advanced age-related macular degeneration (AMD).
Methods:
In this retrospective study, 38 eyes from 38 patients diagnosed with drusen were analyzed. The drusen area and volume were measured using spectral-domain optical coherence tomography (SD-OCT; Cirrus 5000, Carl Zeiss Meditec) with an automated retinal pigment epithelium elevation map algorithm. To minimize bias from variable follow-up intervals, an annualized classification framework was adopted. Based on percentage change in drusen area within the 5-mm circle, eyes were categorized as progressed (increase >20%), stable (change within ±20%), or regressing (decrease >20%).
Results:
Both drusen area and volume increased significantly up to 24 months (area, p = 0.003; volume, p = 0.028) and then showed a modest decline at 36 months, remaining above baseline levels. No significant difference in the proportions of progressed, stable, or regressing eyes was observed across 12-month intervals or compared with baseline (all p > 0.05). A larger baseline 5-mm drusen area was significantly associated with the development of advanced AMD (adjusted odds ratio, 2.818; 95% confidence interval, 1.022–7.767; p = 0.045). Eyes that exhibited at least one episode of drusen regression showed a higher incidence of advanced AMD (36.8% vs. 5.3%, p = 0.042).
Conclusions
Drusen in South Korean patients demonstrated dynamic morphological remodeling over time. Drusen regression was not a benign phenomenon but rather a potential high-risk marker for progression to advanced AMD. These findings highlight the importance of population-specific, quantitative SD-OCT monitoring for early risk stratification in East Asian eyes.
4.Improving prediction of ypT0–1N0 response in rectal cancer: the added value of gross tumor type to magnetic resonance tumor regression grade after chemoradiotherapy in a retrospective cohort study
Kyong-Min KANG ; Mi-Jeong CHOI ; Hong-min AHN ; Heung-Kwon OH ; Duck-Woo KIM ; Jungheum CHO ; Won CHANG ; Young Hoon KIM ; Kyoung Ho LEE ; Yu Kyung JUN ; Yonghoon CHOI ; Sung-Bum KANG
Annals of Surgical Treatment and Research 2026;110(4):237-245
Purpose:
While MRI-based tumor regression grade (mrTRG) has shown promise in evaluating pathologic response to concurrent chemoradiotherapy (CCRT) in rectal cancer, its ability to predict pathologic complete response remains limited.This study aimed to enhance mrTRG’s diagnostic performance in predicting ypT0–1N0 status, a key factor in considering non-radical management after CCRT for locally advanced rectal cancer (LARC).
Methods:
This retrospective study included 430 patients with LARC who underwent radical resection following CCRT at a single referral hospital between April 2018 and September 2024. Multivariable logistic regression was used to identify predictive factors associated with achieving ypT0–1N0 status. The diagnostic performances of mrTRG1–2 alone and in combination with other factors were assessed by comparing sensitivity, specificity, positive-predictive value (PPV), negative-predictive value, and area under the curve (AUC).
Results:
Ninety-three patients (21.6%) achieved ypT0–1N0. In the multivariable analysis, fungating type, cT1–2, and mrTRG1–2 were independent predictors for ypT0–1N0. Integrating mrTRG with gross tumor type yielded the highest AUC of 0.689 among the combined models. For predicting ypT0–1N0, the combination of mrTRG and gross tumor type improved PPV (79.2% vs. 41.5% for mrTRG alone) while also demonstrating enhanced sensitivity compared with ycT0–1N0, the conventional MRI-based predictor (40.9% vs. 22.6%).
Conclusion
This study demonstrated that combining mrTRG and gross tumor type improved the PPV of mrTRG in predicting ypT0–1N0 after CCRT in LARC. Further studies are warranted to validate the role of gross tumor type in refining predictive systems for selecting candidates for non-radical treatment.
5.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.
6.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
7.Influence of Incidental Pulmonary Nodules on Surgical Decision-Making in Thyroid Cancer: a Nationwide Survey
Ja Kyung LEE ; Sukmin YUN ; Eunji KIM ; Yoon KONG ; Hyeong Won YU ; Min Joo KIM ; Jae Hoon MOON ; June Young CHOI
International Journal of Thyroidology 2026;19(1):68-77
Background and Objectives:
The clinical significance of incidental pulmonary nodules detected during thyroid cancer evaluation remains unclear. This study aimed to investigate how such findings affect surgical decisionmaking and whether management differs by physician characteristics.
Materials and Methods:
A web-based survey was distributed to 722 active members of the Korean Thyroid Association in March 2025. Eligible participants included board-certified endocrinologists, endocrine surgeons, and otolaryngologists actively treating thyroid cancer. The questionnaire included clinical scenarios featuring incidental lung nodules found during thyroid cancer work-up, with respondents asked to choose preferred surgical extent (thyroid lobectomy vs. total thyroidectomy) and management approaches.
Results:
Out of 72 physicians who completed the survey, half (n=36, 50.0%) of the respondents answered that the presence of incidental lung nodules could influence their decision on thyroidectomy extent. Among those influenced by lung nodules, 86.1% recommended total thyroidectomy in patients with high- or intermediate-risk thyroid cancer, while 11.1% would do so for all thyroid cancer patients.Endocrinologists, compared to surgeons, were more likely to choose total thyroidectomy in patients with preoperative incidental lung nodules (78.3% vs. 36.7%, p=0.001).
Conclusion
Incidental lung nodules may influence surgical planning in clinicians due to the risk of micrometastasis from thyroid cancer. Endocrinologists tend to favor a more extensive surgical approach compared to surgeons, reflecting greater concern for potential metastatic disease. These findings underscore the need for multidisciplinary consensus guidelines for the management of incidental pulmonary nodules in thyroid cancer patients.
8.Establishing an Active Vaccine Safety Surveillance System Using Large Scale Databases in Korea: Lessons and Scalable Insights for Global Application
Jin Gu YOON ; Eliel NHAM ; Yu Jung CHOI ; Min Joo CHOI ; Won Suk CHOI ; Young Kyung YOON ; Yu Bin SEO ; Hakjun HYUN ; Jung Yeon HEO ; Jin-Soo LEE ; Chung-Jong KIM ; Ji Yun NOH ; Joon Young SONG ; Hee Jin CHEONG
Journal of Korean Medical Science 2026;41(1):e47-
Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.
9.Comparative survival outcomes of surgical resection versus radiotherapy after FOLFIRINOX in borderline resectable and locally advanced pancreatic cancer
Jiwon YU ; Jeong Ha LEE ; Hyunju SHIN ; Hee Chul PARK ; Joon Oh PARK ; Jung Yong HONG ; Minsuk KWON ; Ji Eun SHIN ; Kyu Taek LEE ; Kwang Hyuck LEE ; Jong Kyun LEE ; Joo Kyung PARK ; Young Hoon CHOI ; Jin Seok HEO ; In Woong HAN ; Sang Hyun SHIN ; Hongbeom KIM ; Ji Hye MIN ; Jeong Il YU
Precision and Future Medicine 2026;10(1):39-50
Purpose:
This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control.
Methods:
We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR.
Results:
Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37).
Conclusion
Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.
10.Smoking Experience before Adulthood Is Associated with an Increased Risk of Developing Ulcerative Colitis in Adult Ex-Smokers
Yu Kyung JUN ; Bongseong KIM ; Yonghoon CHOI ; Cheol Min SHIN ; Young Soo PARK ; Nayoung KIM ; Dong Ho LEE ; Kyungdo HAN ; Hyuk YOON
Yonsei Medical Journal 2025;66(1):9-15
Purpose:
Smoking may have a protective role in developing ulcerative colitis (UC) but have the opposite effect on Crohn’s disease (CD). This study aimed to determine the risk of developing inflammatory bowel disease (IBD) according to smoking status and onset age of smoking.
Materials and Methods:
We collected data on the smoking experiences of participants aged 20–39 years who underwent biannual examinations provided by the Korean National Health Screening Program from 2009 to 2012. IBD diagnosis was identified using the National Health Insurance Service. The risk of IBD according to smoking status and onset age of smoking was analyzed after adjusting for major clinical variables.
Results:
During a median 10.59-year follow-up, the risk of UC in ex-smokers was significantly higher than that in non-smokers, and the earlier ex-smokers started smoking, the higher risk of UC [ex-smokers whose onset age of smoking was <20 years, adjusted hazard ratio (aHR) 1.928, 95% confidence interval (CI)=1.649–2.255; 20–24 years, aHR 1.728, 95% CI=1.541–1.939; 25–29 years, aHR 1.676, 95% CI=1.489–1.887; ≥30 years, aHR 1.226, 95% CI=1.010–1.486]. The risk of UC was significantly lower in current smokers whose onset age of smoking was 25–29 years than in non-smokers (aHR 0.825, 95% CI=0.709–0.959). The risk of CD did not differ according to smoking status and onset age of smoking.
Conclusion
Ex-smokers who started smoking at a young age have a high risk of UC, even after adjusting for the smoking amount.

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