1.Unexpected Cancellation of Radioactive Iodine Treatment after Thyroid Hormone Withdrawal: Lessons from a Case Series
Hye-Seon OH ; Won Gu KIM ; Won Bae KIM ; Jin-Sook RYU ; Min Ji JEON ; Tae Yong KIM
Endocrinology and Metabolism 2026;41(2):300-307
Background:
Radioactive iodine treatment (RAIT) is an essential therapy for differentiated thyroid cancer. However, unforeseen complications arising during thyroid hormone withdrawal (THW) can lead to Cancellation of the scheduled treatment. This study aimed to identify cases in which THW-RAIT was discontinued due to THW-related complications and to explore potentially preventable causes to improve patient management.
Methods:
Among 4,174 patients who underwent THW-RAIT between 2012 and 2024, 39 did not complete the planned treatment. After excluding Cancellations unrelated to THW, 11 (0.26%) patients with unexpected THW-related medical issues were analyzed.
Results:
The median age of the included patients was 61 years (range, 23 to 70), and 10 were male. The reasons for THW-RAIT Cancellation were hyponatremia (n=1), abnormal liver function (n=1), renal dysfunction (n=3), and combined liver and renal dysfunction (n=6). The patient with hyponatremia was taking a thiazide diuretic. Most cases of liver dysfunction were associated with prior use of herbal medications, whereas renal dysfunction was linked to diuretic or nonsteroidal anti-inflammatory drug use, pre-existing conditions such as single kidney or diabetic nephropathy, or inadequate oral intake during low-iodine preparation. Two cases of concurrent liver and renal dysfunction were attributed to rhabdomyolysis following intense exercise or heavy physical labor.
Conclusion
Enhanced patient education, comprehensive pre-treatment assessment, and careful avoidance of high-risk medications are essential to prevent THW-related complications and minimize disruptions in RAIT.
2.Favorable Response to Radioactive Iodine Therapy in Papillary Thyroid Carcinoma with Malignant Pleural Effusion
Meihua JIN ; Cha A KIM ; Won Gu KIM
International Journal of Thyroidology 2026;19(1):104-109
Malignant pleural effusion (MPE) is a rare but severe complication of differentiated thyroid carcinoma (DTC). MPE typically occurs in advanced disease and is often refractory to radioiodine (RAI) therapy, resulting in poor survival outcomes. We report a rare case of a 52-year-old male with MPE present at the time of DTC diagnosis who demonstrated a favorable response to RAI therapy. The patient underwent three cycles of high-dose RAI (200 mCi each), resulting in sustained disease control. Despite the typical refractoriness of MPE in DTC, this case illustrates that when RAI avidity is preserved, combined treatment with RAI and supportive interventions such as thoracentesis and pleurodesis can lead to improved outcomes. This case highlights the importance of individualized treatment strategies and suggests that even advanced cases with MPE may benefit from aggressive RAI-based therapy when appropriately selected.
3.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.
4.Two Clinical Cases of Compulsive Sexual Behavior and Illegal Voyeurism: Report and Discussion
Seon Young PARK ; Ung Gu KANG ; Jaehyun KIM ; Myung Je SUNG
Journal of Korean Neuropsychiatric Association 2026;65(1):50-57
This paper reports two clinical cases of men in their twenties who presented with compulsive sexual behaviors characterized by excessive pornography use and illegal voyeuristic activities. Although both individuals maintained otherwise adequate social and academic functioning, they experienced psychological distress and faced legal consequences stemming from their inability to control their sexual impulses. Pharmacological treatment with naltrexone and fluoxetine was associated with a reduction in their compulsive urges. Compulsive sexual behavior disorder (CSBD) has not yet been formally included in the Diagnostic and Statistical Manual of Mental Disorders (DSM), and its status as a potential behavioral addiction remains under debate. Voyeuristic behavior is classified within paraphilic disorders, which are considered diagnostically separate from CSBD despite substantial clinical overlap. These cases contribute to the ongoing discussions regarding the conceptualization of CSBD and highlight the importance of recognizing and expanding the therapeutic approaches for individuals struggling with impaired sexual impulse control.
5.Lithium and Clozapine in Suicide Prevention:Diagnosis-Specific Evidence and Principles for Clinical Practice
Journal of Korean Neuropsychiatric Association 2026;65(1):1-9
Suicide prevention remains one of the most complex and important tasks in psychiatric practice.Lithium and clozapine have long been considered potential anti-suicidal agents, but the strength and scope of their evidence are largely diagnosis-specific. In clinical settings, however, these drugs are occasionally used in broader contexts, including cases where suicidal ideation itself becomes the primary indication. This raises the need to critically examine how pharmacologic interventions should be applied within appropriate diagnostic and therapeutic frameworks. This review synthesizes existing evidence on lithium and clozapine and discusses their roles within the broader landscape of suicide prevention. Suicide is not a unitary symptom but a multifactorial outcome shaped by biological, psychological, and social determinants. Accordingly, pharmacologic treatment should be understood as one component of a multidimensional strategy that integrates psychotherapy, crisis intervention, and social support systems. From an interpretive standpoint, this review highlights the importance of aligning medication use with established evidence while maintaining clinical flexibility and individualized care. The goal was not to depreciate the therapeutic value of lithium or clozapine but to contextualize their use within a rational, diagnosis-informed, and ethically grounded framework. This paper contributes to a more nuanced and evidence-based model of suicide prevention in psychiatric practice by reinforcing such an integrative approach.
6.Comparative Effects of Isometric Exercise Types on 24-Hour Ambulatory Blood Pressure in Young Men with Prehypertension: An Acute Pilot Trial
Seung Won JUNG ; Hyun Soo SONG ; Sun Jung KIM ; Ho Jeong MIN ; Tae Gu CHOI ; Hyun Jeong KIM ; Sae Young JAE
The Korean Journal of Sports Medicine 2026;44(1):25-33
Purpose:
This study aimed to compare the acute effects of isometric handgrip (IHG) and wall squat (IWS) exercise on 24-hour ambulatory blood pressure (BP) and related indices in young men with prehypertension.
Methods:
Ten young men with prehypertension (aged 25.0±2.3 years) completed three randomized crossover conditions: IHG, IWS, and control. Twenty-four-hour ambulatory BP monitoring was used to assess 24-hour, daytime, and nighttime mean BP, BP variability (BPV; average real variability and standard deviation), morning BP, and nocturnal dipping pattern. Office BP was measured at baseline, 30 minutes, and 90 minutes after each condition.
Results:
Twenty-four hour, daytime, and nighttime systolic and diastolic BP did not differ significantly among conditions. BPV indices also showed no significant between-condition differences across 24-hour, daytime, or nighttime periods. Nocturnal systolic BP dipping averaged 5%–8% and did not differ among conditions, indicating a nondipper pattern in all trials. Morning systolic BP, sleep-trough surge, and prewaking surge were similar across conditions. Office BP showed no significant condition or interaction effects; however, both IHG and IWS tended to lower BP at 90 minutes compared with control session.
Conclusion
A single bout of IHG or IWS did not elicit significant changes in 24-hour ambulatory BP, BPV, morning BP, or dipping pattern in young men with prehypertension. Nonetheless, the small acute reductions in office and morning BP suggest that isometric exercise may have potential as a time-efficient adjunctive strategy for early BP management. Larger and longer-term studies are needed to confirm these findings.
7.Acute Effects of Inspiratory Muscle Strength Exercise on Vascular Function and Shear Pattern in Young Adults
Tae Gu CHOI ; Hyun Soo SONG ; Sun Jung KIM ; Seung Won JUNG ; Byul KIM ; Hyun Jeong KIM ; Sae Young JAE
The Korean Journal of Sports Medicine 2026;44(1):16-24
Purpose:
Inspiratory muscle strength training is a time-efficient strategy for lowering blood pressure, but the acute vascular effects and its hemodynamic characteristics remain unclear. This study aimed to determine the acute effects of inspiratory muscle strength exercise (IMSE) on vascular function and shear patterns.
Methods:
In a single-arm acute trial, 12 young adults (aged 26±2 years) performed a single bout of IMSE (about 8 minutes) consisting of 30 breaths (6 breaths×5 sets) at 60% of maximal inspiratory pressure. Vascular function indices were assessed as endothelial function and arterial stiffness. Measurements of endothelial function via flow-mediated dilation (FMD) in the brachial artery and arterial stiffness by carotid-femoral pulse wave velocity (cfPWV) were taken at baseline, 10 minutes, and 40 minutes post-IMSE. Shear rate (SR) responses were continuously obtained throughout the IMSE session at the brachial artery and were analyzed as mean SR, anterograde SR, and retrograde SR.
Results:
Compared to baseline, cfPWV significantly decreased (7.95±0.9 m/sec to 7.49±0.9 m/sec, p=0.033) and FMD increased (4.76%±1.0% to 6.26%±1.1%, p< 0.001) at post-10 min. Both cfPWV and FMD returned to baseline levels at post-40 min. During IMSE, mean SR and anterograde SR significantly increased (both, p< 0.05), whereas retrograde SR decreased (p=0.032) during inter-set rest periods. In addition, rhythmic fluctuations in SR were observed corresponding to inspiration and expiration phases.
Conclusion
These findings suggest that an acute bout of IMSE is associated with improved endothelial function and arterial stiffness. IMSE may elicit distinct hemodynamic responses during exercise, which may be linked to improvements in vascular function.
8.Tumor-Associated Macrophage Infiltration and PD-L1 Expression in Gastric Cancer According to a Modified TCGA-Based Classification
Boram SONG ; Dong-Hoe KOO ; Eo Jin KIM ; In-Gu DO ; Jinah CHU ; Kyungeun KIM ; Hyebin LEE ; Min-Jung KWON ; Jung Ho PARK ; Byung Ho SON ; Chang Hak YOO ; Seoung Wan CHAE
Journal of Gastric Cancer 2026;26(2):247-259
Purpose:
Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood.
Materials and Methods:
We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared.
Results:
A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes.
Conclusions
GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.
9.Modeling Fatigue and Work Stress in Aircraft Maintenance Personnel at Sultan Hasanuddin Airport, Makassar, Indonesia: A PLS-SEM Study on Quality of Life
Lalu Muhammad SALEH ; Syamsiar Siang RUSSENG ; Mahfuddin YUSBUD ; Tae-Gu KIM ; Nurul Mawaddah SYAFITRI ; Fatimah Azzahrah ZAINUDDIN ; Andi Alifah Kultsum Umniyah TENRI
Journal of Preventive Medicine and Public Health 2026;59(3):308-317
Objectives:
This study aimed to develop and test a comprehensive model analyzing direct and indirect relationships among workload, demographic factors, fatigue, work stress, and quality of life among aircraft maintenance personnel (AMP).
Methods:
This cross-sectional study was conducted at the maintenance, repair, and overhaul facility at Sultan Hasanuddin Airport, Makassar. Data collection combined structured interviews, standardized questionnaires (the NASA Task Load Index, Work Fatigue Feeling Measurement Questionnaire, Depression Anxiety Stress Scale-21, and World Health Organization Quality of Life-BREF), and objective measures (a Cocoro Meter for stress and an oximeter for physical workload). The model was examined using partial least squares structural equation modeling (PLS-SEM), which is well-suited to complex models with latent variables and non-normally distributed data.
Results:
In the PLS-SEM analysis, physical workload (β=0.229, p=0.018) and work experience (β=0.277, p=0.007) were significantly and directly associated with fatigue. Age significantly predicted work stress (β=0.371, p=0.001). Crucially, fatigue (β=−0.344, p=0.002) and work stress (β=−0.385, p<0.001) had significant negative direct effects on quality of life and were central mediators. No direct effects of exogenous variables on quality of life were observed. Cross-tabulation supported these findings; subgroups with higher physical demands, longer tenure, and older age reported greater fatigue, higher stress, and lower quality of life.
Conclusions
Fatigue and work stress are pivotal mediators that are significantly associated with reduced quality of life among AMP. Interventions to reduce physical workload and provide targeted support for more experienced and older workers may improve well-being and safety in the aviation maintenance industry.
10.Effects of the FXR agonist GW4064on metabolic disorders in db/db mice
Kyuho KIM ; Ye-Jee LEE ; Jae-Seung YUN ; Yu-Bae AHN ; Seung-Hyun KO
Laboratory Animal Research 2026;42(1):36-42
Background:
Farnesoid X receptor (FXR) is known to play important roles in glucose and lipid metabolism. We aimed to evaluate effects of FXR agonist on metabolic disorders in db/db mice. Seven week-old db/db mice were injected FXR agonist GW4064 (30 mg/kg/day) or carrier solution (dimethyl sulfoxide) intraperitoneally for 4 weeks. Body weight, food intake, and blood glucose levels were measured weekly. Glucose tolerance test and insulin tolerance test were performed at the end of study. Hepatic genes involed in lipogenesis and gluconeogenesis were analyzed by real time polymerase chain reaction. Endoplasmic reticulum stress markers were analyzed by western blot.
Results:
GW4064 treatment significantly attenuated weight gain, and improved glucose intolerance and insulin resistance in db/db mice. In addition, GW4064 treatment significantly repressed hepatic steatosis. GW4064 treatment significantly lowered hepatic gene expression of phosphoenolpyruvate carboxykinase 1, glucose 6-phosphatase, and sterol regulatory element binding protein 1c. GW4064 treatment significantly lowered the protein levels of ATF6, CHOP, Caspase3, and Cleaved Caspase3 in liver. FXR agonist GW4064 showed beneficial effects on weight gain, glucose intolerance, insulin resistance, hepatic steatosis, and hepatic ER stress.
Conclusions
These findings suggest that FXR agonists are promising therapeutic agents for treatment of various metabolic disorders.

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