1.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.
2.Characteristics and Prevalence of Sequelae after COVID-19: A Longitudinal Cohort Study
Se Ju LEE ; Yae Jee BAEK ; Su Hwan LEE ; Jung Ho KIM ; Jin Young AHN ; Jooyun KIM ; Ji Hoon JEON ; Hyeri SEOK ; Won Suk CHOI ; Dae Won PARK ; Yunsang CHOI ; Kyoung-Ho SONG ; Eu Suk KIM ; Hong Bin KIM ; Jae-Hoon KO ; Kyong Ran PECK ; Jae-Phil CHOI ; Jun Hyoung KIM ; Hee-Sung KIM ; Hye Won JEONG ; Jun Yong CHOI
Infection and Chemotherapy 2025;57(1):72-80
Background:
The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments.
Materials and Methods:
We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19.
Results:
During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis.
Conclusion
Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.
3.Impact of HER2-Low Status on Pathologic Complete Response and Survival Outcome Among Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy
Young Joo LEE ; Tae-Kyung YOO ; Sae Byul LEE ; Il Yong CHUNG ; Hee Jeong KIM ; Beom Seok KO ; Jong Won LEE ; Byung Ho SON ; Sei Hyun AHN ; Hyehyun JEONG ; Jae Ho JUNG ; Jin-Hee AHN ; Kyung Hae JUNG ; Sung-Bae KIM ; Hee Jin LEE ; Gyungyub GONG ; Jisun KIM
Journal of Breast Cancer 2025;28(1):11-22
Purpose:
This study analyzed the pathological complete response (pCR) rates, long-term outcomes, and biological features of human epidermal growth factor receptor 2 (HER2)-zero, HER2-low, and HER2-positive breast cancer patients undergoing neoadjuvant treatment.
Methods:
This single-center study included 1,667 patients who underwent neoadjuvant chemotherapy from 2008 to 2014. Patients were categorized by HER2 status, and their clinicopathological characteristics, chemotherapy responses, and recurrence-free survival (RFS) rates were analyzed.
Results:
Patients with HER2-low tumors were more likely to be older (p = 0.081), have a lower histological grade (p < 0.001), and have hormone receptor (HorR)-positive tumors (p < 0.001). The HER2-positive group exhibited the highest pCR rate (23.3%), followed by the HER2-zero (15.5%) and HER2-low (10.9%) groups. However, the pCR rate did not differ between HER2-low and HER2-zero tumors in the HorR-positive or HorR-negative subgroups.The 5-year RFS rates increased in the following order: HER2-low, HER2-positive, and HER2-zero (80.0%, 77.5%, and 74.5%, respectively) (log-rank test p = 0.017). A significant survival difference between patients with HER2-low and HER2-zero tumors was only identified in HorR-negative tumors (5-year RFS for HER2-low, 74.5% vs. HER2-zero, 66.0%; log-rank test p-value = 0.04). Multivariate survival analysis revealed that achieving a pCR was the most significant factor associated with improved survival (hazard ratio [HR], 4.279; p < 0.001).Compared with HER2-zero, the HRs for HER2-low and HER2-positive tumors were 0.787 (p = 0.042) and 0.728 (p = 0.005), respectively. After excluding patients who received HER2-targeted therapy, patients with HER2-low tumors exhibited better RFS than those with HER2-zero (HR 0.784, p = 0.04), whereas those with HER2-positive tumors exhibited no significant difference compared with those with HER2-low tumors (HR, 0.975; p = 0.953).
Conclusion
Patients with HER2-low tumors had no significant difference in pCR rate compared to HER2-zero but showed better survival, especially in HorR-negative tumors.Further investigation into biological differences is warranted.
4.Clinical practice guidelines for cervical cancer: an update of the Korean Society of Gynecologic Oncology Guidelines
Ji Geun YOO ; Sung Jong LEE ; Eun Ji NAM ; Jae Hong NO ; Jeong Yeol PARK ; Jae Yun SONG ; So-Jin SHIN ; Bo Seong YUN ; Sung Taek PARK ; San-Hui LEE ; Dong Hoon SUH ; Yong Beom KIM ; Keun Ho LEE
Journal of Gynecologic Oncology 2025;36(1):e70-
We describe the updated Korean Society of Gynecologic Oncology (KSGO) practice guideline for the management of cervical cancer, version 5.1. The KSGO announced the fifth version of its clinical practice guidelines for the management of cervical cancer in March 2024. The selection of the key questions and the systematic reviews were based on data available up to December 2022. Between 2023 and 2024, substantial findings from large-scale clinical trials and new advancements in cervical cancer research remarkably emerged. Therefore, based on the existing version 5.0, we updated the guidelines with newly accumulated clinical data and added 4 new key questions reflecting the latest insights in the field of cervical cancer. For each question, recommendation was formulated with corresponding level of evidence and grade of recommendation, all established through expert consensus.
5.Effects of an intervention combining warm therapy with a digital distraction app on pain, stress, and satisfaction during intravenous catheterization in South Korea: a randomized controlled trial
Jae-Kyeum LEE ; Ki-Yong KIM ; Yean-Hee JEONG ; Yu-Jin LEE ; Min-Ho LEE ; Myung-Haeng HUR
Journal of Korean Biological Nursing Science 2025;27(2):191-202
Purpose:
This study aimed to evaluate the effects of an intervention combining warm therapy (via a thermoelectric-element tourniquet) and a distraction-based approach (via an augmented reality-based app known as TWINKLE) on pain, stress, and satisfaction during intravenous catheterization in adults.
Methods:
A randomized controlled trial was conducted in South Korea with 93 healthy adults who were randomly assigned to one of three groups: the experimental group (TWINKLE app with warm therapy), the comparison group (warm therapy only), and the control group (no treatment). Participants’ pain, stress, and satisfaction, as well as practitioner satisfaction, were measured after the intervention.
Results:
Pain scores differed significantly among the three groups (F = 5.68, p = .005), with the experimental group showing significantly lower scores than the control group (p = .003). Stress levels were also significantly lower in the experimental group than in the other groups (F = 9.42, p < .001). Participant satisfaction was highest in the experimental group (F = 17.65, p < .001), while nurse satisfaction was significantly higher in the comparison group than in the experimental and control groups (F = 67.91, p < .001), suggesting that the additional distraction intervention may have increased nurses’ workload.
Conclusion
Combining digital distraction with warm therapy using a thermoelectric-element tourniquet effectively reduces pain and stress while improving patient satisfaction during intravenous catheterization. Further research is needed to optimize this approach, with a particular focus on targeting digital distraction interventions to patients with higher levels of procedural anxiety and finding ways to minimize practitioner workload.
6.Correlation Between the Distance From Donors and Ischemic Time in Heart Transplantation of Korea and Its Clinical Impact
Jung Yeon JIN ; Chee-hoon LEE ; Mi Hee LIM ; Soo Yong LEE ; Min Ho JU ; Hyung Gon JE
Journal of Korean Medical Science 2025;40(11):e60-
Background:
The heart donor allocation system in South Korea is divided into three regions, with priority given to recipients within the same region over those in other regions of the same tier. It is commonly believed that heart transplantation (HT) within the same region can reduce ischemic time (IT), although its clinical impact remains unclear. The purpose of this study is to compare the characteristics and outcomes of intra-region HT and inter-region HT.
Methods:
From 2014 to 2022, a total of 115 adult patients underwent isolated HT at a tertiary hospital. Of these, 58 recipients (54.5 ± 10.3 years, female, 36.2%) underwent intra-region HT and 57 recipients (53.9 ± 14.1 years, female, 31.6%) underwent inter-region HT. Extracorporeal membrane oxygenation-bridged HTs accounted for 50.0% and 54.4% of cases, respectively (P = 0.638). There were no differences in preoperative characteristics between the two groups.
Results:
The median inter-hospital distance (38.0 [32.0–112.0] km vs. 351.0 [300.0–390.5] km, P < 0.001) and total IT (153 [123–170] minute vs. 265 [243–298] minute, P < 0.001) were longer in the inter-region group than intra-region group. Despite these differences, both groups showed similar clinical outcomes. The 30-day mortality rates were 5.2% and 5.3% (P < 0.99), respectively. There were no differences in postoperative cardiac index, early adverse outcomes, or long-term survival between the two groups. The inter-hospital distance and cold IT showed a strong positive correlation (time [minute] = 39.462 + 0.410 × distance [km]).
Conclusion
Despite the difference in IT, there was no difference in postoperative outcomes between the two groups. Based on these findings, the effect of donor location on the outcomes of HT in South Korea is not considered significant.
7.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.
8.Long-Term Incidence of Gastrointestinal Bleeding Following Ischemic Stroke
Jun Yup KIM ; Beom Joon KIM ; Jihoon KANG ; Do Yeon KIM ; Moon-Ku HAN ; Seong-Eun KIM ; Heeyoung LEE ; Jong-Moo PARK ; Kyusik KANG ; Soo Joo LEE ; Jae Guk KIM ; Jae-Kwan CHA ; Dae-Hyun KIM ; Tai Hwan PARK ; Kyungbok LEE ; Hong-Kyun PARK ; Yong-Jin CHO ; Keun-Sik HONG ; Kang-Ho CHOI ; Joon-Tae KIM ; Dong-Eog KIM ; Jay Chol CHOI ; Mi-Sun OH ; Kyung-Ho YU ; Byung-Chul LEE ; Kwang-Yeol PARK ; Ji Sung LEE ; Sujung JANG ; Jae Eun CHAE ; Juneyoung LEE ; Min-Surk KYE ; Philip B. GORELICK ; Hee-Joon BAE ;
Journal of Stroke 2025;27(1):102-112
Background:
and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes.
Methods:
We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data.
Results:
Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4.
Conclusion
Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.
9.Switch to Rosuvastatin Plus Ezetimibe From Statin Monotherapy to Achieve Target LDL-Cholesterol Goal: A Multi-Center, Open-Label, Single-Arm Trial
Hong-Kyun PARK ; Jong-Ho PARK ; Hee-Kwon PARK ; Kyusik KANG ; Keun-Hwa JUNG ; Beom Joon KIM ; Jin-Man JUNG ; Young Seo KIM ; Yong-Seok LEE ; Hyo Suk NAM ; Yeonju YU ; Juneyoung LEE ; Keun-Sik HONG
Journal of Stroke 2025;27(2):275-278
10.The Korean Organ Transplant Registry (KOTRY): Third Official Adult Heart Transplant Report
Hyo-In CHOI ; Sang Eun LEE ; Junho HYUN ; Darae KIM ; Dong-Ju CHOI ; Eun-Seok JEON ; Hae-Young LEE ; Hyun-Jai CHO ; Hyungseop KIM ; In-Cheol KIM ; Jaewon OH ; Minjae YOON ; Jin Joo PARK ; Jin-Oh CHOI ; Min Ho JU ; Seok-Min KANG ; Soo Yong LEE ; Sung-Ho JUNG ; Jae-Joong KIM
Korean Circulation Journal 2025;55(2):79-96
Background and Objectives:
The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients.
Methods:
Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage.
Results:
The median ages of the recipients and donors were 56.0 and 43.0 years, respectively.Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival.
Conclusions
In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.

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