1.The Emerging Patterns of New Psychoactive Substance–Related Fatalities in South Korea: A Retrospective Study of Forensic Autopsy Cases
Sohyung PARK ; Han Na KIM ; Youngjin JEON ; Minjung KIM ; Seon Jung JANG ; Jeong Hwa KWON
Korean Journal of Legal Medicine 2026;50(2):39-52
New psychoactive substances (NPS) have rapidly emerged in illicit drug markets worldwide and are increasingly encountered in postmortem examinations. However, postmortem data on NPS-related deaths remain limited worldwide. This study describes postmortem findings from forensic autopsy cases in which NPS were detected and explores the characteristics of these deaths through a retrospective review. Six postmortem cases were identified between 2023 and 2024. The cases predominantly involved young adults. Toxicological analysis identified synthetic cannabinoids, dissociatives, and a stimulant, either alone or in combination with alcohol or conventional illicit drugs such as methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Drug paraphernalia or a documented history of drug use was identified in only some cases. The causes of death included acute intoxication and traumatic deaths in which drug intoxication may have contributed to abnormal behavior and fatal outcomes. These findings provide preliminary forensic evidence of the emergence of NPS in South Korea. They underscore the importance of postmortem examination with comprehensive toxicological screening and continued surveillance of emerging psychoactive substances in forensic practice. They also suggest the value of reviewing a history of prior substance use even in unexpected sudden deaths not initially suspected to be drugrelated.
2.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.
3.Status and appropriateness of fasting in the emergency department
Kangbum LEE ; Stephen Gyung Won LEE ; Chang Seob JANG ; Sa Ran LEE ; Hyeonjeong KIM ; Jeong Hwa HONG ; Sumin LEE ; Yeon Kyung KIM
Journal of the Korean Society of Emergency Medicine 2026;37(2):82-88
Objective:
Prolonged fasting has been reported to have a negative effect on patient outcomes. Although fasting is routinely practiced in the emergency department (ED), there is limited evidence on the current status and appropriateness of fasting in the ED. This study examined the status and appropriateness of fasting in the ED and identified the characteristics of patients who experienced unnecessary fasting.
Methods:
A retrospective observational study was performed at an urban ED in Seoul, Korea. The fasting status and characteristics of adult patients who visited the ED and were admitted or discharged between April 1 and April 30, 2022, were analyzed. A checklist for discontinuing fasting in the ED was used to screen for unnecessary fasting.
Results:
Among 2,292 patients who met the study inclusion criteria, all patients were instructed to begin fasting upon ED arrival. Fasting was discontinued by the physician’s order in 300 patients (13.1%). Patients remained fasting for 92.0%±23.2% of their total ED length of stay. Of the 1,577 patients eligible for fasting discontinuation according to the checklist, 249 patients (15.8%) were ordered to discontinue fasting, and 1,328 patients (84.2%) experienced unnecessary fasting.
Conclusion
ED patients spent significant time fasting during their ED length of stay. A high prevalence of unnecessary fasting was identified in the ED.
4.Reimbursement rate determination for home-visit oral health care services using Time-Driven Activity-Based Costing
Bo-Ram SHIN ; Se-Rim JO ; Jong-Hwa JANG
Journal of Korean Academy of Oral Health 2026;50(1):39-46
Objectives:
This study aimed to quantify the actual resource utilization and cost structure of homevisit oral health care services using a Time-Driven Activity-Based Costing (TDABC) approach, in response to the growing demand for efficient home-based care for older adults.
Methods:
An analytical framework comprising 12 domains and 78 activities, validated through a Delphi study, was applied to home‑visit oral health care records. A total of 100 home‑visit service logs recorded by ten dental hygienists participating in an integrated care program in Cheonan City between March and April 2024 were analyzed. Data collected included activity time, consumable supply, travel time and distance, and transportation expenses. A capacity cost rate incorporating both direct and indirect costs was used to estimate activity‑level costs and total costs per visit.
Results:
Dental hygienists conducted an average of 6.43 visits per day. The mean travel time and distance per visit were 15.04 min and 7.31 km, respectively. Transportation expenses averaged 9,740 KRW per visit, and consumable supply costs ranged from 1,428 to 9,738 KRW per patient, depending on oral health status. The calculated capacity cost rate was 487 KRW/min, resulting in activity-based costs of 66,232 KRW per visit across the 78 activities. When transportation time costs were added (7,324 KRW; 15.04 min×487 KRW/min), the total cost per visit was estimated at 73,556 KRW. Preparation and infection control activities were identified as major cost drivers.
Conclusions
The TDABC approach provided a comprehensive estimate of the cost structure of home-visit oral health care services, capturing expenditures associated with travel, preparation, and documentation. These findings provide evidence to support sustainable reimbursement models within long-term care and integrated care systems.
5.Risk of Osteoporotic Fractures among Patients with Thyroid Cancer: A Nationwide Population-Based Cohort Study
Eu Jeong KU ; Won Sang YOO ; Yu Been HWANG ; Subin JANG ; Jooyoung LEE ; Shinje MOON ; Eun Kyung LEE ; Hwa Young AHN
Endocrinology and Metabolism 2025;40(2):225-235
Background:
The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group.
Methods:
This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated.
Results:
Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures.
Conclusion
In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.
6.Molecular Classification of Breast Cancer Using Weakly Supervised Learning
Wooyoung JANG ; Jonghyun LEE ; Kyong Hwa PARK ; Aeree KIM ; Sung Hak LEE ; Sangjeong AHN
Cancer Research and Treatment 2025;57(1):116-125
Purpose:
The molecular classification of breast cancer is crucial for effective treatment. The emergence of digital pathology has ushered in a new era in which weakly supervised learning leveraging whole-slide images has gained prominence in developing deep learning models because this approach alleviates the need for extensive manual annotation. Weakly supervised learning was employed to classify the molecular subtypes of breast cancer.
Materials and Methods:
Our approach capitalizes on two whole-slide image datasets: one consisting of breast cancer cases from the Korea University Guro Hospital (KG) and the other originating from The Cancer Genomic Atlas dataset (TCGA). Furthermore, we visualized the inferred results using an attention-based heat map and reviewed the histomorphological features of the most attentive patches.
Results:
The KG+TCGA-trained model achieved an area under the receiver operating characteristics value of 0.749. An inherent challenge lies in the imbalance among subtypes. Additionally, discrepancies between the two datasets resulted in different molecular subtype proportions. To mitigate this imbalance, we merged the two datasets, and the resulting model exhibited improved performance. The attentive patches correlated well with widely recognized histomorphologic features. The triple-negative subtype has a high incidence of high-grade nuclei, tumor necrosis, and intratumoral tumor-infiltrating lymphocytes. The luminal A subtype showed a high incidence of collagen fibers.
Conclusion
The artificial intelligence (AI) model based on weakly supervised learning showed promising performance. A review of the most attentive patches provided insights into the predictions of the AI model. AI models can become invaluable screening tools that reduce costs and workloads in practice.
7.The kinetics of nucleolar precursor bodies clustering at the pronuclei interface: Positive correlations with the morphokinetic characteristics of cleaving embryos and euploidy in preimplantation genetic testing programs
Hwa Soon OH ; Jung Mi JANG ; Hye Jin YOON ; Chang Woo CHOO ; Kyung Sil LIM ; Jin Ho LIM ; Yong-Pil CHEON
Clinical and Experimental Reproductive Medicine 2025;52(2):150-156
Objective:
This study investigated potential relationships between the kinetics of nucleolar precursor bodies (NPBs) in the pronucleus and developmental morphokinetics and euploidy in human preimplantation genetic testing for aneuploidy (PGT-A) cycles.
Methods:
The morphokinetic analysis of 200 blastocysts obtained from 53 PGT-A cycles was performed retrospectively in a time-lapse incubator. At the time of pronuclear breakdown (PNBD), we categorized the blastocysts into two groups based on the kinetic degree of clustering NPBs at the interface of the two pronuclei: clustered NPBs (CL) and non-clustered NPBs (NCL). We then compared morphokinetic parameters, abnormal behavioral events, and the rate of aneuploidy between the two groups.
Results:
Pronuclear fading and the first cleavage occurred earlier in the NCL group than in the CL group. However, the initiation of blastocyst formation and blastocyst expansion was delayed in the NCL group relative to the CL group. No differences were found in the rate of abnormal cleavage events, such as multinucleation at the 2-cell stage, direct cleavage from one to three cells, and from two to five cells between the CL and NCL groups. However, the fragmentation rate at the 8-cell stage was higher in the NCL group than in the CL group (10.3% vs. 1.9%, p<0.05). Additionally, the euploid rate in the CL group was significantly higher than in the NCL group (37.9% vs. 12.4%, p<0.05).
Conclusion
These results demonstrate the effectiveness of combining NPB clustering at PNBD with morphokinetics as a parameter for selecting embryos with higher developmental potential in in vitro fertilization.
8.Complete mouth rehabilitation with fixed implant-supported prosthesis in an edentulous maxilla using dental CAD-CAM technology
Jeong Eun HONG ; Hwa-Ryun CHA ; Ji-Won BANG ; Seong-A KIM ; Keun-Woo LEE ; Yong-Sang LEE ; Hee-Won JANG
The Journal of Korean Academy of Prosthodontics 2025;63(2):194-202
For patients with edentulous maxillae, creating a prosthetic treatment plan involves considering anatomical factors, aesthetics, the patient’s financial situation, and oral hygiene capabilities. In this case, CAD-CAM technology was used to accurately plan implant placements for a full arch fixed restoration based on the design of the final prosthesis. A customized surgical guide ensured precise implant placement and a provisional restoration was created using CAD-CAM. The definitive prosthesis was then created based on the second provisional restoration that has been previously used and adjusted by the patient. This approach achieved an excellent functional and aesthetic outcome, highlighting the benefits of digital approach and its potential for further clinical applications.
9.Predictive value and optimal cut-off level of high-sensitivity troponin T in patients with acute pulmonary embolism
Moojun KIM ; Chang-Ok SEO ; Yong-Lee KIM ; Hangyul KIM ; Hye Ree KIM ; Yun Ho CHO ; Jeong Yoon JANG ; Jong-Hwa AHN ; Min Gyu KANG ; Kyehwan KIM ; Jin-Sin KOH ; Seok-Jae HWANG ; Jin Yong HWANG ; Jeong Rang PARK
The Korean Journal of Internal Medicine 2025;40(1):65-77
Background/Aims:
Elevated troponin levels predict in-hospital mortality and influence decisions regarding thrombolytic therapy in patients with acute pulmonary embolism (PE). However, the usefulness of high-sensitivity troponin T (hsTnT) regarding PE remains uncertain. We aimed to establish the optimal cut-off level and compare its performance for precise risk stratification.
Methods:
374 patients diagnosed with acute PE were reviewed. PE-related adverse outcomes, a composite of PE-related deaths, cardiopulmonary resuscitation incidents, systolic blood pressure < 90 mmHg, and all-cause mortality within 30 days were evaluated. The optimal hsTnT cut-off for all-cause mortality, and the net reclassification index (NRI) was used to assess the incremental value in risk stratification.
Results:
Among 343 normotensive patients, 17 (5.0%) experienced all-cause mortality, while 40 (10.7%) had PE-related adverse outcomes. An optimal hsTnT cut-off value of 60 ng/L for all-cause mortality (AUC 0.74, 95% CI 0.61–0.85, p < 0.001) was identified, which was significantly associated with PE-related adverse outcomes (OR 4.07, 95% CI 2.06–8.06, p < 0.001). Patients with hsTnT ≥ 60 ng/L were older, hypotensive, had higher creatinine levels, and right ventricular dysfunction signs. Combining hsTnT ≥ 60 ng/L with simplified pulmonary embolism severity index ≥1 provided additional prognostic information. Reclassification analysis showed a significant shift in risk categories, with an NRI of 1.016 ± 0.201 (p < 0.001).
Conclusions
We refined troponin’s predictive value in patients with acute PE, proposing a new cut-off value of hsTnT ≥ 60 ng/L. Validation through large-scale studies is essential to offer clinically useful guidance for managing patient population.
10.Relationship between the Geriatric Nutrition Risk Index and the Prognosis of Severe Coronavirus Disease 2019 in Korea
Hye Ju YEO ; Daesup LEE ; Mose CHUN ; Jin Ho JANG ; Sunghoon PARK ; Su Hwan LEE ; Onyu PARK ; Tae Hwa KIM ; Woo Hyun CHO
Tuberculosis and Respiratory Diseases 2025;88(2):369-379
Background:
Malnutrition exacerbates the prognosis of numerous diseases; however, its specific impact on severe coronavirus disease 2019 (COVID-19) outcomes remains insufficiently explored.
Methods:
This multicenter study in Korea evaluated the nutritional status of 1,088 adults with severe COVID-19 using the Geriatric Nutritional Risk Index (GNRI) based on serum albumin levels and body weight. The patients were categorized into two groups: GNRI >98 (no-risk) and GNRI ≤98 (risk). Propensity score matching, adjusted for demographic and clinical variables, was conducted.
Results:
Of the 1,088 patients, 642 (59%) were classified as at risk of malnutrition. Propensity score matching revealed significant disparities in hospital (34.3% vs. 19.4%, p<0.001) and intensive care unit (ICU) mortality (31.5% vs. 18.9%, p<0.001) between the groups. The risk group was associated with a higher hospital mortality rate in the multivariate Cox regression analyses following propensity score adjustment (hazard ratio [HR], 1.64; p=0.001). Among the 670 elderly patients, 450 were at risk of malnutrition. Furthermore, the risk group demonstrated significantly higher hospital (52.1% vs. 29.5%, p<0.001) and ICU mortality rates (47.2% vs. 29.1%, p<0.001). The risk group was significantly associated with increased hospital mortality rates in the multivariate analyses following propensity score adjustment (HR, 1.66; p=0.001).
Conclusion
Malnutrition, as indicated by a low GNRI, was associated with increased mortality in patients with severe COVID-19. This effect was also observed in the elderly population. These findings underscore the critical importance of nutritional assessment and effective interventions for patients with severe COVID-19.

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