1.Molecular and Phenotypic Characterization of Fluid-Derived Patient-Derived Cell and Organoid Models in Advanced Gastric Cancer
Ye Jin MOON ; Woo Sun KWON ; Chan Hee PARK ; Jinsoo JANG ; Juin PARK ; Byeong Gyu YOON ; Han Byeol MUN ; Namju KIM ; Choong-kun LEE ; Hei Cheul JEUNG ; Su-Jin SHIN ; Tae Soo KIM ; Sun Young RHA
Journal of Gastric Cancer 2026;26(2):260-278
Purpose:
Patient-derived cells (PDCs) and patient-derived organoids (PDOs) are complementary preclinical models widely used in translational cancer research. However, their molecular and functional differences have not been systematically characterized. This study established and analyzed paired PDC and PDO models derived from the same gastric cancer ascites to delineate platform-dependent molecular and functional profiles.
Materials and Methods:
Malignant ascites or pleural fluid obtained from 6 patients with advanced gastric cancer were used to establish paired PDC and PDO models. All pairs underwent comprehensive multi-omics profiling, integrating genomic, transcriptomic, and proteomic data. Phenotypic characterization included morphological, histological, proliferative, and cell cycle analyses. Drug sensitivity assays were performed using 4 chemotherapeutic agents commonly used to treat gastric cancer.
Results:
The 6 paired PDC and PDO models exhibited distinct morphological characteristics.Whole-genome analyses demonstrated high concordance among primary tumors, PDCs, and PDOs, confirming tumor representation across platforms. Multi-omics profiling identified platform-dependent molecular signatures; PDOs were enriched for extracellular matrix remodeling and stemness, whereas PDCs displayed proliferation- and immune-related signatures. Clinically relevant biomarkers, including HER2 and MET alterations, were concordant with primary tumors. Notably, drug responses differed between platforms and patients, indicating platform-dependent and patient-specific chemosensitivity.
Conclusions
Paired PDC and PDO models derived from the same patients preserved core patient-specific tumor characteristics while exhibiting distinct molecular and functional profiles. These findings underscore the culture platform as a critical determinant of experimental outcomes and therapeutic responses. Therefore, careful selection of an appropriate preclinical model is essential to accurately address biological questions and optimize precision oncology strategies.
2.Usefulness of computed tomography of the brain in patients with dizziness in emergency room
Taehoon JANG ; You Ho MUN ; Sujeong SHIN
Journal of the Korean Society of Emergency Medicine 2026;37(2):89-94
Objective:
Brain computed tomography (CT) scans are often performed to determine the cause of dizziness in emergency departments (EDs). This study examined the usefulness of brain CT in diagnosing dizziness.
Methods:
This retrospective study examined the medical records of patients aged 18 years or older who visited a single emergency medical center with dizziness from January 1, 2023, to December 31, 2023. The patients’ demographic information, symptoms, and brain CT results were collected. Univariate and multivariate logistic regression were performed.
Results:
A total of 1,428 patients were enrolled. Among them, 45 patients had positive findings on brain CT. In the group of patients with a previous history of cerebrovascular accident (CVA), the proportion of positive brain CT results was higher than in those without a history of CVA (P<0.01). The group with one or more underlying diseases was statistically significant (P=0.02). In patients with nystagmus, the rate of positive brain CT findings was low, but the difference from patients without nystagmus was not statistically significant (0.9%, P=0.05). In patients who had one or more abnormal neurological exam findings, multivariate logistic regression analysis showed that the presence of neurologic exam finding (odds ratio [OR], 3.04; 95% confidence interval [CI], 1.65-5.75; P<0.01), and the presence of nystagmus (OR, 0.12; 95% CI, 0.03-0.55; P<0.01) were associated with positive findings on brain CT.
Conclusion
Brain CT has limited diagnostic value in patients with dizziness presenting to the emergency room. This imaging modality should be performed in limited situations where central-type vertigo is suspected. Even in these cases, other diagnostic modalities such as MRI should be considered.
3.Delayed Retroperitoneal Hematoma Following Intradiscal Electrothermal Therapy: A Case Report of a Rare Complication
Jun-Yong CHA ; Yun-Young PARK ; Jin-Uk KIM ; Jun-Ho LEE ; Seong-Hwan MUN ; Gun AHN ; Il-Tae JANG
The Nerve 2026;12(1):36-40
Intradiscal electrothermal therapy (IDET) is a minimally invasive procedure used to treat discogenic back pain and offers an alternative to surgical intervention in selected patients. Although it is generally considered safe, rare but significant complications can occur and may be difficult to diagnose because their symptoms overlap with those of other spinal conditions. We describe the case of a 69-year-old woman who presented with severe lower back and left buttock pain that was unresponsive to conservative treatment. Magnetic resonance imaging revealed disc bulging with a high-intensity zone at the L4–5 and L5–S1 levels. IDET was performed at the L4–5 level, resulting in initial pain relief. However, the patient returned 7 days later with recurrent pain. Despite undergoing percutaneous epidural neuroplasty at the left L5–S1 level, a medial branch block, and a piriformis muscle block, her symptoms persisted. Further evaluation with spinal computed tomography revealed a retroperitoneal hematoma near the left psoas muscle. Referred pain from the hematoma mimicked discogenic pain, resulting in delayed diagnosis and unnecessary interventions. The patient remained hemodynamically stable and gradually improved with conservative management alone. This case highlights retroperitoneal hematoma as a rare complication of IDET and emphasizes the importance of accurate and timely diagnosis in patients with persistent or worsening symptoms after spinal procedures. Clinicians should consider non-discogenic sources of pain when treatment outcomes deviate from expected patterns.
4.Effect of regional COVID-19 outbreak to emergency department response on acute myocardial infarction: a multicenter retrospective study
Young Wook KIM ; Sungbae MOON ; Hyun Wook RYOO ; Jae Yun AHN ; Jung Bae PARK ; Dong Eun LEE ; Sang Hun LEE ; Sangchan JIN ; You Ho MUN ; Jung Ho KIM ; Tae Chang JANG
Journal of the Korean Society of Emergency Medicine 2025;36(2):72-82
Objective:
The Daegu region experienced the first wave of the pandemic at the beginning of the coronavirus disease 2019 (COVID-19) outbreak in Korea. Other non-COVID-19-related treatments during a community outbreak, such as cardiovascular diseases, were expected to impact emergency departments. In acute myocardial infarctions, time is an important factor affecting the patient outcome. This study examined how community COVID-19 outbreak affected STsegment elevated myocardial infarction (STEMI) care in emergency departments.
Methods:
A retrospective analysis was performed on patients visiting five emergency departments in the Daegu area who were diagnosed with STEMI from February 18 to April 17 each year from 2018 to 2020. The demographic characteristics, prehospital variables, in-hospital time variables, and treatment results were collected. The cases were divided into the pre-COVID period and the COVID period for comparison.
Results:
The study included 254 patients (194 pre-COVID, 60 during COVID). The symptom-to-door time did not differ. Although the door-to-first doctor time was shortened (4 min vs. 2 min, P=0.01), the rate of coronary angiogram along with the door-to-angiogram time and the door-to-balloon time did not change. The length of stay in the emergency department was delayed during COVID-19 (median, 136 min vs. 404 min; P<0.01). The in-hospital length of stay and mortality were similar in both groups.
Conclusion
The time to treat STEMI was not delayed significantly during the first wave of the COVID-19 outbreak in the Daegu area compared with the pre-pandemic period. Mortality did not change. The length of stay was elongated significantly in the emergency department but not in the hospital.
5.Effect of regional COVID-19 outbreak to emergency department response on acute myocardial infarction: a multicenter retrospective study
Young Wook KIM ; Sungbae MOON ; Hyun Wook RYOO ; Jae Yun AHN ; Jung Bae PARK ; Dong Eun LEE ; Sang Hun LEE ; Sangchan JIN ; You Ho MUN ; Jung Ho KIM ; Tae Chang JANG
Journal of the Korean Society of Emergency Medicine 2025;36(2):72-82
Objective:
The Daegu region experienced the first wave of the pandemic at the beginning of the coronavirus disease 2019 (COVID-19) outbreak in Korea. Other non-COVID-19-related treatments during a community outbreak, such as cardiovascular diseases, were expected to impact emergency departments. In acute myocardial infarctions, time is an important factor affecting the patient outcome. This study examined how community COVID-19 outbreak affected STsegment elevated myocardial infarction (STEMI) care in emergency departments.
Methods:
A retrospective analysis was performed on patients visiting five emergency departments in the Daegu area who were diagnosed with STEMI from February 18 to April 17 each year from 2018 to 2020. The demographic characteristics, prehospital variables, in-hospital time variables, and treatment results were collected. The cases were divided into the pre-COVID period and the COVID period for comparison.
Results:
The study included 254 patients (194 pre-COVID, 60 during COVID). The symptom-to-door time did not differ. Although the door-to-first doctor time was shortened (4 min vs. 2 min, P=0.01), the rate of coronary angiogram along with the door-to-angiogram time and the door-to-balloon time did not change. The length of stay in the emergency department was delayed during COVID-19 (median, 136 min vs. 404 min; P<0.01). The in-hospital length of stay and mortality were similar in both groups.
Conclusion
The time to treat STEMI was not delayed significantly during the first wave of the COVID-19 outbreak in the Daegu area compared with the pre-pandemic period. Mortality did not change. The length of stay was elongated significantly in the emergency department but not in the hospital.
6.Effect of regional COVID-19 outbreak to emergency department response on acute myocardial infarction: a multicenter retrospective study
Young Wook KIM ; Sungbae MOON ; Hyun Wook RYOO ; Jae Yun AHN ; Jung Bae PARK ; Dong Eun LEE ; Sang Hun LEE ; Sangchan JIN ; You Ho MUN ; Jung Ho KIM ; Tae Chang JANG
Journal of the Korean Society of Emergency Medicine 2025;36(2):72-82
Objective:
The Daegu region experienced the first wave of the pandemic at the beginning of the coronavirus disease 2019 (COVID-19) outbreak in Korea. Other non-COVID-19-related treatments during a community outbreak, such as cardiovascular diseases, were expected to impact emergency departments. In acute myocardial infarctions, time is an important factor affecting the patient outcome. This study examined how community COVID-19 outbreak affected STsegment elevated myocardial infarction (STEMI) care in emergency departments.
Methods:
A retrospective analysis was performed on patients visiting five emergency departments in the Daegu area who were diagnosed with STEMI from February 18 to April 17 each year from 2018 to 2020. The demographic characteristics, prehospital variables, in-hospital time variables, and treatment results were collected. The cases were divided into the pre-COVID period and the COVID period for comparison.
Results:
The study included 254 patients (194 pre-COVID, 60 during COVID). The symptom-to-door time did not differ. Although the door-to-first doctor time was shortened (4 min vs. 2 min, P=0.01), the rate of coronary angiogram along with the door-to-angiogram time and the door-to-balloon time did not change. The length of stay in the emergency department was delayed during COVID-19 (median, 136 min vs. 404 min; P<0.01). The in-hospital length of stay and mortality were similar in both groups.
Conclusion
The time to treat STEMI was not delayed significantly during the first wave of the COVID-19 outbreak in the Daegu area compared with the pre-pandemic period. Mortality did not change. The length of stay was elongated significantly in the emergency department but not in the hospital.
7.Thirty-Day Mortality of Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia:Insights from a Retrospective Cohort Study
Minji JEON ; Sukbin JANG ; Seok Jun MUN ; Si-Ho KIM
Yonsei Medical Journal 2024;65(12):770-776
Although glycopeptides remain the preferred treatment for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, the treatment of persistent MRSA bacteremia has been challenging. We investigated real-world treatment strategies for persistent MRSA bacteremia, with a specific emphasis on the use of antimicrobial agents and the frequency of changes during the treatment course. We retrospectively identified patients with persistent MRSA bacteremia in four university-affiliated hospitals between 2017 and 2021. The primary objective of this study was to investigate the patterns of antimicrobial uses for MRSA bacteremia. The secondary objectives were evaluating the associated factors with 1) overall 30-day mortality and 2) changing agents during the treatment course. Time-dependent Cox regression analysis was used to adjust for immortal time bias. Among 116 patients, 37.1% underwent antimicrobials switching, primarily prompted by persistent bacteremia. The 30-day mortality rates of groups with and without antimicrobial switching were 21.4% and 44.2%, respectively (p=0.010 by log-rank test); however, after adjustment for immortal time bias, there was no statistical significance between the two groups (adjusted hazard ratio 0.24, 95% confidence interval 0.03–2.17, p=0.238). Only the Pitt bacteremia score on day 4 and pneumonia were associated with 30-day mortality. Meanwhile, the factors associated with antimicrobial switching were the duration of bacteremia, the initial use of teicoplanin, echocardiogram, and Charlson comorbidity index. This study showed that while over one-third of persistent MRSA bacteremia patients experience changes in antimicrobial agents during treatment, this practice does not significantly improve the 30-day mortality. Our study suggests the need for more effective treatment strategies in managing persistent MRSA bacteremia.
8.Introduction to the forensic research via omics markers in environmental health vulnerable areas (FROM) study
Jung-Yeon KWON ; Woo Jin KIM ; Yong Min CHO ; Byoung-gwon KIM ; Seungho LEE ; Jee Hyun RHO ; Sang-Yong EOM ; Dahee HAN ; Kyung-Hwa CHOI ; Jang-Hee LEE ; Jeeyoung KIM ; Sungho WON ; Hee-Gyoo KANG ; Sora MUN ; Hyun Ju YOO ; Jung-Woong KIM ; Kwan LEE ; Won-Ju PARK ; Seongchul HONG ; Young-Seoub HONG
Epidemiology and Health 2024;46(1):e2024062-
This research group (forensic research via omics markers in environmental health vulnerable areas: FROM) aimed to develop biomarkers for exposure to environmental hazards and diseases, assess environmental diseases, and apply and verify these biomarkers in environmentally vulnerable areas. Environmentally vulnerable areas—including refineries, abandoned metal mines, coal-fired power plants, waste incinerators, cement factories, and areas with high exposure to particulate matter—along with control areas, were selected for epidemiological investigations. A total of 1,157 adults, who had resided in these areas for over 10 years, were recruited between June 2021 and September 2023. Personal characteristics of the study participants were gathered through a survey. Biological samples, specifically blood and urine, were collected during the field investigations, separated under refrigerated conditions, and then transported to the laboratory for biomarker analysis. Analyses of heavy metals, environmental hazards, and adducts were conducted on these blood and urine samples. Additionally, omics analyses of epigenomes, proteomes, and metabolomes were performed using the blood samples. The biomarkers identified in this study will be utilized to assess the risk of environmental disease occurrence and to evaluate the impact on the health of residents in environmentally vulnerable areas, following the validation of diagnostic accuracy for these diseases.
9.Recurrence pattern of glioblastoma treated with intensity-modulated radiation therapy versus three-dimensional conformal radiation therapy
So Hwa MUN ; Hong Seok JANG ; Byung Ok CHOI ; Shin Woo KIM ; Jin-Ho SONG
Radiation Oncology Journal 2024;42(3):218-227
Purpose:
To evaluate recurrence patterns of and survival outcomes in glioblastoma treated with intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3D-CRT).
Materials and Methods:
We retrospectively examined 91 patients with glioblastoma treated with either IMRT (n = 60) or 3D-CRT (n = 31) between January 2013 and December 2019. Magnetic resonance imaging showing tumor recurrence and planning computed tomography scans were fused for analyzing recurrence patterns categorized as in-field, marginal, and out-of-field based on their relation to the initial radiation field.
Results:
The median overall survival (OS) was 18.9 months, with no significant difference between the groups. The median progression-free survival (PFS) was 9.4 months, with no significant difference between the groups. Patients who underwent gross total resection (GTR) had higher OS and PFS than those who underwent less extensive surgery. Among 78 relapse cases, 67 were of in-field; 5, marginal; and 19, out-of-field recurrence. Among 3D-CRT-treated cases, 24 were of in-field; 1, marginal; and 9, out-of-field recurrence. Among IMRT-treated cases, 43 were of in-field; 4, marginal; and 10, out-of-field recurrence. In partial tumor removal or biopsy cases, out-of-field recurrence was less frequent in the IMRT (16.2%) than in the 3D-CRT (36.3%) group, with marginal significance (p = 0.079).
Conclusion
IMRT and 3D-CRT effectively managed glioblastoma with no significant differences in OS and PFS. The survival benefit with GTR underscored the importance of maximal surgical resection. The reduced rate of out-of-field recurrence in IMRT-treated patients with partial resection highlights its potential utility in cases with unfeasible complete tumor removal.
10.Thirty-Day Mortality of Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia:Insights from a Retrospective Cohort Study
Minji JEON ; Sukbin JANG ; Seok Jun MUN ; Si-Ho KIM
Yonsei Medical Journal 2024;65(12):770-776
Although glycopeptides remain the preferred treatment for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, the treatment of persistent MRSA bacteremia has been challenging. We investigated real-world treatment strategies for persistent MRSA bacteremia, with a specific emphasis on the use of antimicrobial agents and the frequency of changes during the treatment course. We retrospectively identified patients with persistent MRSA bacteremia in four university-affiliated hospitals between 2017 and 2021. The primary objective of this study was to investigate the patterns of antimicrobial uses for MRSA bacteremia. The secondary objectives were evaluating the associated factors with 1) overall 30-day mortality and 2) changing agents during the treatment course. Time-dependent Cox regression analysis was used to adjust for immortal time bias. Among 116 patients, 37.1% underwent antimicrobials switching, primarily prompted by persistent bacteremia. The 30-day mortality rates of groups with and without antimicrobial switching were 21.4% and 44.2%, respectively (p=0.010 by log-rank test); however, after adjustment for immortal time bias, there was no statistical significance between the two groups (adjusted hazard ratio 0.24, 95% confidence interval 0.03–2.17, p=0.238). Only the Pitt bacteremia score on day 4 and pneumonia were associated with 30-day mortality. Meanwhile, the factors associated with antimicrobial switching were the duration of bacteremia, the initial use of teicoplanin, echocardiogram, and Charlson comorbidity index. This study showed that while over one-third of persistent MRSA bacteremia patients experience changes in antimicrobial agents during treatment, this practice does not significantly improve the 30-day mortality. Our study suggests the need for more effective treatment strategies in managing persistent MRSA bacteremia.

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