1.Diagnostic Accuracy of Serological Tests for Mycoplasma pneumoniae Infections in Children with Pneumonia, Based on Symptom Onset
Gahee KIM ; Ki Wook YUN ; Dayun KANG ; Taek Jin LEE ; Byung Wook EUN ; Hyunju LEE ; Yae-Jean KIM ; Doo Ri KIM ; Areum SHIN ; Hyun Mi KANG ; Ye Ji KIM ; Byung Ok KWAK ; Younghee LEE ; Ye Kyung KIM ; Young June CHOE ; Woosuck SUH ; Kyo Jin JO ; Kyung-Ran KIM ; Eun Young CHO ; Kyung Min KIM ; Joon Kee LEE ; Su Eun PARK
Annals of Laboratory Medicine 2026;46(2):162-170
Background:
Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP.
Methods:
From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days).
Results:
Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days.
Conclusions
The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.
2.Development and Validation of an Analytical Method for the Simultaneous Determination of Three Marker Compounds in Wikstroemia trichotoma
Min-Ji KEEM ; Taek-Hwan KWON ; Beom-Geun JO ; Sangho CHOI ; Jin-Hyub PAIK ; Young Suk JUNG ; Eun-Ju JEONG ; Su-Nam KIM ; Min Hye YANG
Natural Product Sciences 2026;32(1):84-92
The Wikstroemia genus is highly regarded in traditional Asian medicine for its diverse therapeutic applications, including the treatment of inflammatory and infectious conditions. Among its members,Wikstroemia trichotoma (Thunb.) Makino remains a promising medicinal resource which is yet to be chemicallycharacterized. To ensure the chemical consistency of W. trichotoma, we developed and validated the first HPLC method for the simultaneous quantification of three major marker compounds: chlorogenic acid (1), miconioside B (2), and matteucinol 7-O-apiofuranosyl(1→6)-glucopyranoside (3). Chromatographic separation was achieved on a C18 column using a gradient elution system of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Detection was optimized using a photodiode array (PDA) detector at 280 and 325 nm, based on the absorption maxima of the markers. The method was validated in accordance with the International Council for Harmonisation (ICH) and the Ministry of Food and Drug Safety (MFDS) guidelines. The results demonstrated high linearity (r2 > 0.999), with limits of detection and quantitation ranging from 4.28–6.42 and 12.97–19.47 μg/ mL, respectively. Intra- and inter-day precision (% RSD ≤ 1.83%) and accuracy (recoveries of 92.5–101.7%) were within acceptable limits. Quantitative analysis revealed the contents of 1, 2, and 3 in the W. trichotoma extract to be 19.9, 139.8, and 264.9 mg/g, respectively. This study provides a reliable analytical framework for the standardization, quality control, and future pharmacological evaluation of W. trichotoma.
3.Vitamin/mineral and non-vitamin/ non-mineral supplement use of breast cancer survivors in Korea
Jioh KANG ; Jiyoung YOUN ; Hyun Jeong CHO ; Hyeong-Gon MOON ; Dong-Young NOH ; So-Youn JUNG ; Eun Sook LEE ; Zisun KIM ; Hyun Jo YOUN ; Jihyoung CHO ; Young Bum YOO ; Se Kyung LEE ; Jeong Eon LEE ; Seok Jin NAM ; Jun Won MIN ; Yoo Seok KIM ; Jihyoun LEE ; Seho PARK ; Joon JEONG ; Jung Eun LEE
Nutrition Research and Practice 2026;20(2):333-345
BACKGROUND/OBJECTIVES:
Dietary supplement use is common among breast cancer survivors, but studies on Asian populations remain limited. This study investigated dietary supplement use among Korean breast cancer survivors, distinguishing between vitamin/ mineral (VM) and non-vitaminon-mineral (NVNM) supplements.
SUBJECTS/METHODS:
This cross-sectional study included 1,136 stage I–III breast cancer survivors from 12 Korean hospitals, who survived more than 6 mon post-surgery. The participants completed a questionnaire on post-diagnostic dietary supplement use. Stepwise logistic regression was applied, calculating odds ratios (ORs) and 95% confidence intervals (CIs) to identify the demographic and clinical factors associated with VM and NVNM use.
RESULTS:
Seventy percent of survivors reported supplement use, with 25% using a single product. The most common VM supplements were multivitamins/minerals, vitamin D, and vitamin C, while the most common NVNM supplements included omega-3 fatty acids, probiotics, and ginseng. Survivors with higher education and greater physical activity were more likely to use VM supplements (ORs [95% CIs], 2.74 [1.76–4.25] for college graduates or above vs. middle school or below; 1.38 [1.02–1.88] for the most active group vs. the least active group). NVNM use was associated with higher education, greater physical activity levels, and a history of smoking (ORs [95% CIs], 2.29 [1.46–3.58] for college graduates or above vs. middle school or below; 1.52 [1.13–2.06] for the most active group vs. the least active group; 2.00 [1.23–3.25] for ever smokers vs. never smokers). Survivors who had undergone chemotherapy were also more likely to use NVNM supplements than those who had not (OR [95% CI], 1.37 [1.02–1.84]).
CONCLUSION
Seventy percent of Korean breast cancer survivors used dietary supplements in this study. VM use was associated with higher education and physical activity, while higher NVNM use was associated with higher education, greater physical activity, a history of smoking, and chemotherapy.
4.Outcomes of Lung Transplantation for Bronchiolitis Obliterans after Hematopoietic Stem Cell Transplantation Compared with Those for Idiopathic Pulmonary Fibrosis
Bong Suk PARK ; Ha Eun KIM ; Young Ho YANG ; Dae Joon KIM ; Chang Young LEE ; Byung Jo PARK ; A La WOO ; Eun Young KIM ; Moo Suk PARK ; Song Yee KIM ; Jin Gu LEE
Yonsei Medical Journal 2026;67(1):27-33
Purpose:
Bronchiolitis obliterans syndrome (BOS) can develop as a manifestation of graft-versus-host disease following allogeneic hematopoietic stem cell transplantation (allo-HSCT), and may ultimately require lung transplantation (LT). However, reports on LT outcomes for BOS after allo-HSCT are limited. This study aimed to compare the outcomes of LT for BOS following allo-HSCT with those for idiopathic pulmonary fibrosis (IPF).
Materials and Methods:
A total of 487 patients underwent LT between January 2010 and August 2023. Among them, the baseline characteristics and outcomes of 35 patients with BOS following allo-HSCT and 216 patients with IPF were analyzed.
Results:
The BOS group was younger and had a lower body mass index (BMI) compared to the IPF group (33.7±11.9 years vs.59.7±7.3 years, p<0.001; 17.6±3.7 kg/m2 vs. 22.0±3.6 kg/m2 , p<0.001, respectively). The proportion of male patients was lower in the BOS group than in the IPF group (54.3% vs. 84.3%, p<0.001). Preoperative ventilator support was more common in the BOS group compared to the IPF group (62.9% vs. 32.4%, p=0.001). In Kaplan–Meier survival analysis, the 5-year survival rate was significantly higher in the BOS group than in the IPF group (71.0% vs. 44.9%, p=0.022). In the Cox proportional hazards model, age was the only factor significantly associated with survival [hazard ratio (95% confidence interval): 1.04 (1.02–1.07), p<0.001].
Conclusion
The survival rate of the BOS group was not inferior to that of the IPF group after adjusting for sex, age, and BMI. Therefore, LT should be actively considered as a treatment option for patients with BOS following allo-HSCT.
5.Resident shortages and their impact on surgical care, defensive medicine, and patient management: a retrospective study in South Korea
Jeong Hee HAN ; Byoung Chul LEE ; Jung Bum CHOI ; Hong Jae JO ; Jae Kyun PARK ; Hyae Jin KIM ; Eun Ji PARK ; Young Hoon JUNG ; Chang In CHOI
Korean Journal of Clinical Oncology 2025;21(1):32-39
Purpose:
This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries.
Methods:
This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon.
Results:
Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%).
Conclusion
The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.
6.Erratum: Korean Gastric Cancer Association-Led Nationwide Survey on Surgically Treated Gastric Cancers in 2023
Dong Jin KIM ; Jeong Ho SONG ; Ji-Hyeon PARK ; Sojung KIM ; Sin Hye PARK ; Cheol Min SHIN ; Yoonjin KWAK ; Kyunghye BANG ; Chung-sik GONG ; Sung Eun OH ; Yoo Min KIM ; Young Suk PARK ; Jeesun KIM ; Ji Eun JUNG ; Mi Ran JUNG ; Bang Wool EOM ; Ki Bum PARK ; Jae Hun CHUNG ; Sang-Il LEE ; Young-Gil SON ; Dae Hoon KIM ; Sang Hyuk SEO ; Sejin LEE ; Won Jun SEO ; Dong Jin PARK ; Yoonhong KIM ; Jin-Jo KIM ; Ki Bum PARK ; In CHO ; Hye Seong AHN ; Sung Jin OH ; Ju-Hee LEE ; Hayemin LEE ; Seong Chan GONG ; Changin CHOI ; Ji-Ho PARK ; Eun Young KIM ; Chang Min LEE ; Jong Hyuk YUN ; Seung Jong OH ; Eunju LEE ; Seong-A JEONG ; Jung-Min BAE ; Jae-Seok MIN ; Hyun-dong CHAE ; Sung Gon KIM ; Daegeun PARK ; Dong Baek KANG ; Hogoon KIM ; Seung Soo LEE ; Sung Il CHOI ; Seong Ho HWANG ; Su-Mi KIM ; Moon Soo LEE ; Sang Hyun KIM ; Sang-Ho JEONG ; Yusung YANG ; Yonghae BAIK ; Sang Soo EOM ; Inho JEONG ; Yoon Ju JUNG ; Jong-Min PARK ; Jin Won LEE ; Jungjai PARK ; Ki Han KIM ; Kyung-Goo LEE ; Jeongyeon LEE ; Seongil OH ; Ji Hun PARK ; Jong Won KIM ;
Journal of Gastric Cancer 2025;25(2):400-402
7.Prospective Multicenter Observational Study on Postoperative Quality of Life According to Type of Gastrectomy for Gastric Cancer
Sung Eun OH ; Yun-Suhk SUH ; Ji Yeong AN ; Keun Won RYU ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Bang Wool EOM ; Joongyub LEE ; Hyuk-Joon LEE ;
Journal of Gastric Cancer 2025;25(2):382-399
Purpose:
This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer.
Materials and Methods:
A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery.
Results:
Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064).
Conclusions
Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.
8.Korean Gastric Cancer AssociationLed Nationwide Survey on Surgically Treated Gastric Cancers in 2023
Dong Jin KIM ; Jeong Ho SONG ; Ji-Hyeon PARK ; Sojung KIM ; Sin Hye PARK ; Cheol Min SHIN ; Yoonjin KWAK ; Kyunghye BANG ; Chung-sik GONG ; Sung Eun OH ; Yoo Min KIM ; Young Suk PARK ; Jeesun KIM ; Ji Eun JUNG ; Mi Ran JUNG ; Bang Wool EOM ; Ki Bum PARK ; Jae Hun CHUNG ; Sang-Il LEE ; Young-Gil SON ; Dae Hoon KIM ; Sang Hyuk SEO ; Sejin LEE ; Won Jun SEO ; Dong Jin PARK ; Yoonhong KIM ; Jin-Jo KIM ; Ki Bum PARK ; In CHO ; Hye Seong AHN ; Sung Jin OH ; Ju-Hee LEE ; Hayemin LEE ; Seong Chan GONG ; Changin CHOI ; Ji-Ho PARK ; Eun Young KIM ; Chang Min LEE ; Jong Hyuk YUN ; Seung Jong OH ; Eunju LEE ; Seong-A JEONG ; Jung-Min BAE ; Jae-Seok MIN ; Hyun-dong CHAE ; Sung Gon KIM ; Daegeun PARK ; Dong Baek KANG ; Hogoon KIM ; Seung Soo LEE ; Sung Il CHOI ; Seong Ho HWANG ; Su-Mi KIM ; Moon Soo LEE ; Sang Hyun KIM ; Sang-Ho JEONG ; Yusung YANG ; Yonghae BAIK ; Sang Soo EOM ; Inho JEONG ; Yoon Ju JUNG ; Jong-Min PARK ; Jin Won LEE ; Jungjai PARK ; Ki Han KIM ; Kyung-Goo LEE ; Jeongyeon LEE ; Seongil OH ; Ji Hun PARK ; Jong Won KIM ; The Information Committee of the Korean Gastric Cancer Association
Journal of Gastric Cancer 2025;25(1):115-132
Purpose:
Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023.
Materials and Methods:
The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys.
Results:
Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively.
Conclusions
The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.
9.Resident shortages and their impact on surgical care, defensive medicine, and patient management: a retrospective study in South Korea
Jeong Hee HAN ; Byoung Chul LEE ; Jung Bum CHOI ; Hong Jae JO ; Jae Kyun PARK ; Hyae Jin KIM ; Eun Ji PARK ; Young Hoon JUNG ; Chang In CHOI
Korean Journal of Clinical Oncology 2025;21(1):32-39
Purpose:
This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries.
Methods:
This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon.
Results:
Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%).
Conclusion
The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.
10.Risk Factors for Perforation in Endoscopic Treatment for Early Colorectal Cancer: A Nationwide ENTER-K Study
Ik Hyun JO ; Hyun Gun KIM ; Young-Seok CHO ; Hyun Jung LEE ; Eun Ran KIM ; Yoo Jin LEE ; Sung Wook HWANG ; Kyeong-Ok KIM ; Jun LEE ; Hyuk Soon CHOI ; Yunho JUNG ; Chang Mo MOON
Gut and Liver 2025;19(1):95-107
Background/Aims:
Early colorectal cancer (ECC) is commonly resected endoscopically. Perforation is a devastating complication of endoscopic resection. We aimed to identify the characteristics and predictive risk factors for perforation related to endoscopic resection of ECC.
Methods:
This nationwide retrospective multicenter study included patients with ECC who underwent endoscopic resection. We investigated the demographics, endoscopic findings at the time of treatment, and histopathological characteristics of the resected specimens. Logistic regression analysis was used to investigate the clinical factors associated with procedure-related perforations. Survival analysis was conducted to assess the impact of perforation on the overall survival of patients with ECC.
Results:
This study included 965 participants with a mean age of 63.4 years. The most common endoscopic treatment was conventional endoscopic mucosal resection (n=573, 59.4%), followed by conventional endoscopic submucosal dissection (n=259, 26.8%). Thirty-three patients (3.4%) experienced perforations, most of which were managed endoscopically (n=23/33, 69.7%). Patients who undergo endoscopic submucosal dissection-hybrid and precut endoscopic mucosal resection have a higher risk of perforation than those who undergo conventional endoscopic mucosal resection (odds ratio, 78.65 and 39.72, p<0.05). Procedure-related perforations were not associated with patient survival.
Conclusions
Perforation after endoscopic resection had no significant impact on the prognosis of ECC. The type of endoscopic resection was a crucial predictor of perforation. Large-scale prospective studies are needed to further investigate endoscopic resection of ECC.

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