1.The Impact of COVID-19 on Admissions and In-hospital Mortality of Patients With Stroke in Korea: An Interrupted Time Series Analysis
Youngs CHANG ; Soo-Hee HWANG ; Haibin BAI ; Seowoo PARK ; Eunbyul CHO ; Dohoung KIM ; Hyejin LEE ; Jin Yong LEE
Journal of Preventive Medicine and Public Health 2025;58(1):60-71
Objectives:
This study aimed to investigate the impact of coronavirus disease 2019 (COVID-19) on admission rates and in-hospital mortality among patients with ischemic and hemorrhagic stroke.
Methods:
We constructed a dataset detailing the monthly hospitalizations and mortality rates of inpatients with stroke from January 2017 to December 2021. Employing an interrupted time series analysis, we explored the impact of COVID-19 on hospitalizations and 30-day in-hospital mortality among stroke patients.
Results:
The number of ischemic stroke admissions decreased by 18.5%, from 5335 to 4348, immediately following the COVID-19 outbreak (p<0.001). The in-hospital mortality rate for ischemic stroke increased slightly from 3.3% to 3.4% immediately after the outbreak, although it showed a decreasing trend over time. The number of hemorrhagic stroke admissions fell by 7.5%, from 2014 to 1864, immediately following the COVID-19 outbreak. The 30-day in-hospital mortality rate for hemorrhagic stroke initially decreased from 12.9% to 12.7%, but subsequently showed an increasing trend.
Conclusions
We confirmed that COVID-19 impacted both the admission and death rates of stroke patients. The admission rate for both ischemic and hemorrhagic strokes decreased, while in-hospital mortality increased. Specifically, in-hospital mortality from ischemic stroke rose initially after the outbreak before stabilizing. Additionally, our findings indicate variable effects based on sex, age, and socioeconomic status, suggesting that certain groups may be more susceptible. This underscores the need to identify and support vulnerable populations to mitigate adverse health outcomes.
2.Who Dies Alone? Demographics, Underlying Diseases, and Healthcare Utilization Patterns of Lonely Death Individuals in Korea
Haibin BAI ; Jae-ryun LEE ; Min Jung KANG ; Young-Ho JUN ; Hye Yeon KOO ; Jieun YUN ; Jee Hoon SOHN ; Jin Yong LEE ; Hyejin LEE
Journal of Preventive Medicine and Public Health 2025;58(2):218-226
Objectives:
Lonely death is defined as “a person living in a state of social isolation, disconnected from family, relatives, and others, who dies from suicide, illness, or other causes”. This study investigated the characteristics of individuals who die alone in Korea.
Methods:
We constructed a database of lonely death cases by linking data from the Korea Crime Scene Investigation Unit of the Korea National Police Agency with National Health Insurance Service (NHIS) records. A descriptive analysis was performed to evaluate the demographics, underlying diseases, and healthcare utilization patterns among lonely death cases.
Results:
Among the 3122 individuals identified as lonely death cases, 2621 (84.0%) were male and 501 (16.0%) were female. The most common age group was 50-59 years (n=930, 29.8%). The NHIS covered 2161 individuals (69.2%), whereas 961 individuals (30.8%) were enrolled in Medical Aid (MA). The highest number of lonely deaths occurred in Seoul areas, with 1468 cases (47.0%). Mood disorders were diagnosed in 1020 individuals (32.7%), and various alcohol-related diseases, including alcoholic liver disease, were also observed. Outpatient visits increased leading up to death but declined in the final 3 months, while hospitalizations decreased and emergency room visits slightly increased.
Conclusions
Most lonely death cases involved male in their 50s, with a disproportionately high number of MA beneficiaries compared to the general population. Many of these individuals also experienced mental health issues or alcohol-related disorders. Preventing social isolation and strengthening social safety nets are critical to reducing the occurrence of lonely deaths.
3.Sphingomonas Paucimobilis-derived Extracellular Vesicles Reverse Aβ-induced Dysregulation of Neurotrophic Factors, Mitochondrial Function, and Inflammatory Factors through MeCP2-mediated Mechanism
Eun-Hwa LEE ; Hyejin KWON ; So-Young PARK ; Jin-Young PARK ; Jin-Hwan HONG ; Jae-Won PAENG ; Yoon-Keun KIM ; Pyung-Lim HAN
Experimental Neurobiology 2025;34(1):20-33
Recent studies have shown an increased abundance of Sphingomonas paucimobilis, an aerobic, Gram-negative bacterium with a distinctive cell envelope rich in glycosphingolipids, within the gut microbiome of individuals with Alzheimer Disease (AD). However, the fact that S. paucimobilis is a well-known pathogen associated with nosocomial infections presents a significant challenge in investigating whether its presence in the gut microbiome is detrimental or beneficial, particularly in the context of AD. This study examines the impact of S. paucimobilis-derived extracellular vesicles (Spa-EV) on Aβ-induced pathology in cellular and animal models of AD. Microarray analysis reveals that Spa-EV treatment modulates Aβ42-induced alterations in gene expression in both HT22 neuronal cells and BV2 microglia cells. Among the genes significantly affected by SpaEV, notable examples include Bdnf, Nt3/4, and Trkb, which are key players of neurotrophic signaling; Pgc1α, an upstream regulator of mitochondrial biogenesis; Mecp2 and Sirt1, epigenetic factors that regulate numerous gene expressions; and Il1β, Tnfα, and Nfκb-p65, which are associated with neuroinflammation. Remarkably, Spa-EV effectively reverses Aβ42-induced alteration in the expression of these genes through the upregulation of Mecp2. Furthermore, administration of Spa-EV in Tg-APP/PS1 mice restores the reduced expression of neurotrophic factors, Pgc1α, MeCP2, and Sirt1, while suppressing the increased expression of proinflammatory genes in the brain. Our results indicate that Spa-EV has the potential to reverse Aβ-induced dysregulation of gene expression in neuronal and microglial cells. These alterations encompass those essential for neurotrophic signaling and neuronal plasticity, mitochondrial function, and the regulation of inflammatory processes.
4.The Effects of Semi-Occluded Vocal Tract Exercises on Presbyphonia in Elderly Women: Two Case Reports
HyeJin LIM ; Dong Won LEE ; Jeong Kyu KIM ; Seong-Hee CHOI
Journal of the Korean Society of Laryngology Phoniatrics and Logopedics 2025;36(1):32-38
This case report investigates the effects of semi-occluded vocal tract exercises (SOVTEs) on voice improvement in elderly female patients with presbyphonia. Elderly female patients with presbyphonia commonly present with symptoms such as hoarseness, decreased vocal intensity, and phonatory difficulties. These symptoms are often associated with age-related vocal fold atrophy, leading to compensatory muscle tension and inefficient phonation, which necessitate targeted therapeutic interventions. In this study, two elderly female patients, aged 73 years and 71 years, participated in a voice therapy program centered on SOVTEs designed to promote vocal fold vibration efficiency and reduce compensatory tension. Case 1 underwent five therapy sessions, while Case 2 completed sixteen sessions. Pre- and post-treatment voice assessments revealed notable improvements in vocal quality, suggesting that SOVTEs may be an effective therapeutic approach for managing presbyphonia in elderly women.
5.Variability in the Length of Stay and Daily Medical Expenses in Inpatient Care in Korea, 2010–2019:Hypertension and Pneumonia
Haejong LEE ; Jin-Won NOH ; Sanghee LEE ; Jung-Kyu CHOI ; Jin Yong LEE ; Hyejin LEE ; Jung-Hoe KIM
Journal of Korean Medical Science 2025;40(13):e120-
This study examined the variability in the length of stay (LOS) and daily medical expenses (DME) for hypertension and pneumonia inpatient care. Using 10 years of National Health Insurance Service data (2010–2019), a multilevel analysis assessed variability at the patient and institutional levels. During the study period, the mean LOS decreased, whereas the DME increased for both hypertension and pneumonia. Institutional level variability in the LOS increased during the study period, demonstrating greater variability than that for pneumonia. For both conditions, institutional-level variability was more marked in smaller institutions (hospitals and clinics) than in larger institutions (general and tertiary hospitals).These findings indicate a need for standardized healthcare service protocols to promote consistent and efficient patient care.
6.Gaps and Similarities in Research Use LOINC Codes Utilized in Korean University Hospitals: Towards Semantic Interoperability for Patient Care
Kuenyoul PARK ; Min-Sun KIM ; YeJin OH ; John Hoon RIM ; Shinae YU ; Hyejin RYU ; Eun-Jung CHO ; Kyunghoon LEE ; Ha Nui KIM ; Inha CHUN ; AeKyung KWON ; Sollip KIM ; Jae-Woo CHUNG ; Hyojin CHAE ; Ji Seon OH ; Hyung-Doo PARK ; Mira KANG ; Yeo-Min YUN ; Jong-Baeck LIM ; Young Kyung LEE ; Sail CHUN
Journal of Korean Medical Science 2025;40(1):e4-
Background:
The accuracy of Logical Observation Identifiers Names and Codes (LOINC) mappings is reportedly low, and the LOINC codes used for research purposes in Korea have not been validated for accuracy or usability. Our study aimed to evaluate the discrepancies and similarities in interoperability using existing LOINC mappings in actual patient care settings.
Methods:
We collected data on local test codes and their corresponding LOINC mappings from seven university hospitals. Our analysis focused on laboratory tests that are frequently requested, excluding clinical microbiology and molecular tests. Codes from nationwide proficiency tests served as intermediary benchmarks for comparison. A research team, comprising clinical pathologists and terminology experts, utilized the LOINC manual to reach a consensus on determining the most suitable LOINC codes.
Results:
A total of 235 LOINC codes were designated as optimal codes for 162 frequent tests.Among these, 51 test items, including 34 urine tests, required multiple optimal LOINC codes, primarily due to unnoted properties such as whether the test was quantitative or qualitative, or differences in measurement units. We analyzed 962 LOINC codes linked to 162 tests across seven institutions, discovering that 792 (82.3%) of these codes were consistent. Inconsistencies were most common in the analyte component (38 inconsistencies, 33.3%), followed by the method (33 inconsistencies, 28.9%), and properties (13 inconsistencies, 11.4%).
Conclusion
This study reveals a significant inconsistency rate of over 15% in LOINC mappings utilized for research purposes in university hospitals, underlining the necessity for expert verification to enhance interoperability in real patient care.
7.Variability in the Length of Stay and Daily Medical Expenses in Inpatient Care in Korea, 2010–2019:Hypertension and Pneumonia
Haejong LEE ; Jin-Won NOH ; Sanghee LEE ; Jung-Kyu CHOI ; Jin Yong LEE ; Hyejin LEE ; Jung-Hoe KIM
Journal of Korean Medical Science 2025;40(13):e120-
This study examined the variability in the length of stay (LOS) and daily medical expenses (DME) for hypertension and pneumonia inpatient care. Using 10 years of National Health Insurance Service data (2010–2019), a multilevel analysis assessed variability at the patient and institutional levels. During the study period, the mean LOS decreased, whereas the DME increased for both hypertension and pneumonia. Institutional level variability in the LOS increased during the study period, demonstrating greater variability than that for pneumonia. For both conditions, institutional-level variability was more marked in smaller institutions (hospitals and clinics) than in larger institutions (general and tertiary hospitals).These findings indicate a need for standardized healthcare service protocols to promote consistent and efficient patient care.
8.Gaps and Similarities in Research Use LOINC Codes Utilized in Korean University Hospitals: Towards Semantic Interoperability for Patient Care
Kuenyoul PARK ; Min-Sun KIM ; YeJin OH ; John Hoon RIM ; Shinae YU ; Hyejin RYU ; Eun-Jung CHO ; Kyunghoon LEE ; Ha Nui KIM ; Inha CHUN ; AeKyung KWON ; Sollip KIM ; Jae-Woo CHUNG ; Hyojin CHAE ; Ji Seon OH ; Hyung-Doo PARK ; Mira KANG ; Yeo-Min YUN ; Jong-Baeck LIM ; Young Kyung LEE ; Sail CHUN
Journal of Korean Medical Science 2025;40(1):e4-
Background:
The accuracy of Logical Observation Identifiers Names and Codes (LOINC) mappings is reportedly low, and the LOINC codes used for research purposes in Korea have not been validated for accuracy or usability. Our study aimed to evaluate the discrepancies and similarities in interoperability using existing LOINC mappings in actual patient care settings.
Methods:
We collected data on local test codes and their corresponding LOINC mappings from seven university hospitals. Our analysis focused on laboratory tests that are frequently requested, excluding clinical microbiology and molecular tests. Codes from nationwide proficiency tests served as intermediary benchmarks for comparison. A research team, comprising clinical pathologists and terminology experts, utilized the LOINC manual to reach a consensus on determining the most suitable LOINC codes.
Results:
A total of 235 LOINC codes were designated as optimal codes for 162 frequent tests.Among these, 51 test items, including 34 urine tests, required multiple optimal LOINC codes, primarily due to unnoted properties such as whether the test was quantitative or qualitative, or differences in measurement units. We analyzed 962 LOINC codes linked to 162 tests across seven institutions, discovering that 792 (82.3%) of these codes were consistent. Inconsistencies were most common in the analyte component (38 inconsistencies, 33.3%), followed by the method (33 inconsistencies, 28.9%), and properties (13 inconsistencies, 11.4%).
Conclusion
This study reveals a significant inconsistency rate of over 15% in LOINC mappings utilized for research purposes in university hospitals, underlining the necessity for expert verification to enhance interoperability in real patient care.
9.Bladder Cancer Medication Bacillus Calmette-Guérin-Cell Wall Skeleton Focusing on Alternatives and Developments to Limitations
Hyejin LEE ; Hyerim JANG ; Jeongyeon KIM ; Seoyeon MAENG ; Jihye KIM
Journal of Cancer Prevention 2025;30(1):1-6
Bacillus Calmette-Guérin (BCG) serves as an anticancer drug for bladder cancer by enhancing the innate immune response and facilitating the expression of beta-defensin-2/-3. BCG is significantly more effective than other treatment modalities; however, it has limitations due to the nonspecific secretion of immune proteins such as interleukin-2 (IL-2) and IFN-γ, necessitating frequent injections that result in toxicity. The newly developed BCG-cell wall skeleton (BCG-CWS) is intended to address the non-specificity and the requirement for repeated treatments associated with BCG. BCG-CWS stimulates antigen-presenting cells by secreting cytokines such as IL-12, using an adjuvant to enhance the immune response and synergize with it to provoke a potent immune reaction. Nevertheless, BCG-CWS encounters issues related to cellular uptake due to the substantial molecular weight of the drug.To meet this challenge, various strategies such as the introduction of R8 protein, the liposome evaporated via an emulsified lipid method, and nanoparticle formulation have been employed which can enhance targeted drug delivery, though issues related to particle size remain unresolved. This paper aims to discuss future perspectives by examining the mechanisms and challenges of BCG-CWS.
10.Sphingomonas Paucimobilis-derived Extracellular Vesicles Reverse Aβ-induced Dysregulation of Neurotrophic Factors, Mitochondrial Function, and Inflammatory Factors through MeCP2-mediated Mechanism
Eun-Hwa LEE ; Hyejin KWON ; So-Young PARK ; Jin-Young PARK ; Jin-Hwan HONG ; Jae-Won PAENG ; Yoon-Keun KIM ; Pyung-Lim HAN
Experimental Neurobiology 2025;34(1):20-33
Recent studies have shown an increased abundance of Sphingomonas paucimobilis, an aerobic, Gram-negative bacterium with a distinctive cell envelope rich in glycosphingolipids, within the gut microbiome of individuals with Alzheimer Disease (AD). However, the fact that S. paucimobilis is a well-known pathogen associated with nosocomial infections presents a significant challenge in investigating whether its presence in the gut microbiome is detrimental or beneficial, particularly in the context of AD. This study examines the impact of S. paucimobilis-derived extracellular vesicles (Spa-EV) on Aβ-induced pathology in cellular and animal models of AD. Microarray analysis reveals that Spa-EV treatment modulates Aβ42-induced alterations in gene expression in both HT22 neuronal cells and BV2 microglia cells. Among the genes significantly affected by SpaEV, notable examples include Bdnf, Nt3/4, and Trkb, which are key players of neurotrophic signaling; Pgc1α, an upstream regulator of mitochondrial biogenesis; Mecp2 and Sirt1, epigenetic factors that regulate numerous gene expressions; and Il1β, Tnfα, and Nfκb-p65, which are associated with neuroinflammation. Remarkably, Spa-EV effectively reverses Aβ42-induced alteration in the expression of these genes through the upregulation of Mecp2. Furthermore, administration of Spa-EV in Tg-APP/PS1 mice restores the reduced expression of neurotrophic factors, Pgc1α, MeCP2, and Sirt1, while suppressing the increased expression of proinflammatory genes in the brain. Our results indicate that Spa-EV has the potential to reverse Aβ-induced dysregulation of gene expression in neuronal and microglial cells. These alterations encompass those essential for neurotrophic signaling and neuronal plasticity, mitochondrial function, and the regulation of inflammatory processes.

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