1.Molecular Epidemiology of Extended-spectrum β-Lactamase-producing Escherichia coli in South Korea: A Korean Global Antimicrobial Resistance Surveillance System Report
Dokyun KIM ; SungYoung LEE ; Jun Sung HONG ; Min Hyuk CHOI ; Hyun Soo KIM ; Young Ree KIM ; Young Ah KIM ; Young UH ; Kyeong Seob SHIN ; Jeong Hwan SHIN ; Jeong Su PARK ; Kyoung Un PARK ; Soo Hyun KIM ; Jong Hee SHIN ; Jungsik YU ; Seok Hoon JEONG
Annals of Laboratory Medicine 2026;46(1):72-82
Background:
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance.
Methods:
We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed.
Results:
Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55.
Conclusions
Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.
2.Spatiotemporal Remodeling of Enteric Neural Pathways Underlies ColonicDysmotility Following Spinal Cord Injury in Rats
Min Seob KIM ; Sei KIM ; Se Eun HA ; Hyun Seok CHOI ; Myeong Hwan YU ; Jisong YOU ; Dahyun SEON ; Do Hee LEE ; Min Cheol JOO ; Yong Sung KIM ; Suck Chei CHOI ; Joong Goo KWON ; Kyung Sik PARK ; Hyun Jin KIM ; Seungil RO ; Moon Young LEE
Journal of Neurogastroenterology and Motility 2026;32(1):86-98
Background/Aims:
Spinal cord injury (SCI) frequently impairs defecation, severely affecting the quality of life. This study examines compensatory neural remodeling after SCI, focusing on basal colonic contractility, neural responses to electrical field stimulation, and alterations in excitatory cholinergic and inhibitory nitrergic pathways.
Methods:
Female Sprague–Dawley rats underwent either sham surgery or T10 spinal cord transection and were categorized into 3 groups: sham, 1-week post-SCI (acute), and 4-week post-SCI (chronic). Colonic contractility was assessed in an organ bath using electrical field stimulation in the presence of a nitric oxide synthase inhibitor. Neural protein expression was analyzed by immunofluorescence and Western blotting.
Results:
SCI produced region- and time-dependent impairments in colonic contractility, with distinct alterations in the proximal circular and longitudinal muscles across acute and chronic phases. Neural excitability shifted dynamically, showing enhanced excitatory activity in the proximal longitudinal muscle at 1-week and the distal circular muscle at 4-week post-SCI. Protein analysis revealed increased neuronal nitric oxide synthase in the proximal colon, decreasedsoluble guanylyl cyclase in the distal colon, upregulated muscarinic M3 receptor in the proximal colon, and reduced vaso-active intestinal peptide receptor 1 in both proximal and distal regions.
Conclusion
SCI induces spatiotemporal remodeling of excitatory and inhibitory neural pathways, contributing to colonic dysmotility and revealing potential targets for therapeutic intervention.
3.Clinical Guideline for the Use of Biodegradable Rectal Spacers During Radiotherapy for Prostate Cancer
Hyun Ho HAN ; Jong Kyou KWON ; Do Kyung KIM ; Jin Hyung JEON ; Chan Woo WEE ; Jae Ho CHO ; Ji Hee JUNG ; A Young YOO ; Jae Young JOUNG ; Gee Hyun SONG ; Seung Ju LEE ; Won PARK ; Chan Kyo KIM ; Young Seok KIM ; Yeon Joo KIM ; Ah Ram CHANG ; Jae Sik KIM ; Sung Hwan BAE ; Byoung Kyu HAN ; Kang Su CHO
Journal of Urologic Oncology 2026;24(1):3-12
Purpose:
Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT.
Materials and Methods:
This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system.
Results:
Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised.
Conclusion
Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.
4.Postoperative Readmission Is Associated With Worse Oncologic Outcomes After Radical Cystectomy for Bladder Cancer: A Multicenter Study of 3,972 Patients
Jungwon PARK ; Jong Ho PARK ; Sangchul LEE ; Seung-Hwan JEONG ; Ja Hyeon KU ; Kyung Hwan KIM ; Jong Kil NAM ; Bumjin LIM ; BumSik HONG ; Wook NAM ; Sung Gu KANG ; Seok Ho KANG ; Tae Gyun KWON ; Tae-Hwan KIM ; Jieun HEO ; Won Sik HAM ; Geehyun SONG ; Ho Kyung SEO ; Wan SONG ; Hyun Hwan SUNG ; Byong Chang JEONG ; Jong Jin OH
Journal of Urologic Oncology 2026;24(1):69-78
Purpose:
Radical cystectomy (RC) is associated with substantial postoperative morbidity, and unplanned readmission remains common despite advances in perioperative management. However, the association between postoperative readmission due to complications and oncologic outcomes after RC for bladder cancer has not been clearly defined. We evaluated the impact of postoperative readmission on overall survival (OS) and cancer-specific survival (CSS) after RC for bladder cancer.
Materials and Methods:
We retrospectively analyzed 3,972 patients who underwent RC for bladder cancer in a multicenter cohort. Postoperative readmission was defined as unplanned hospitalization within 90 days postsurgery due to surgery-related complications. Survival outcomes were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify independent predictors of OS and CSS.
Results:
Among the study population, 916 patients (23.1%) experienced postoperative readmission. Baseline and perioperative characteristics were generally comparable between patients with and without readmission. Kaplan-Meier analyses demonstrated significantly worse OS and CSS among patients who experienced postoperative readmission (both log-rank p<0.001). In multivariable analyses adjusting for clinicopathological factors, postoperative readmission remained independently associated with worse OS (hazard ratio [HR], 1.654; 95% confidence interval [CI], 1.464–1.868; p<0.001) and CSS (HR, 1.761; 95% CI, 1.509–2.055; p<0.001).
Conclusion
Postoperative readmission within 90 days after RC was independently associated with inferior long-term oncologic outcomes. These findings suggest the importance of strategies aimed at preventing postoperative complications and subsequent readmission.
5.Intradialytic hypotension and worse outcomes in patients with acute kidney injury requiring intermittent hemodialysis
Yeong-Won PARK ; Donghwan YUN ; Yeojin YU ; Sang Hyun KIM ; Sehoon PARK ; Yong Chul KIM ; Dong Ki KIM ; Kook-Hwan OH ; Kwon Wook JOO ; Yon Su KIM ; Seong Geun KIM ; Seung Seok HAN
Kidney Research and Clinical Practice 2026;45(1):77-85
Background:
Intradialytic hypotension (IDH) is a critical complication related to worse outcomes in patients undergoing maintenance hemodialysis. Herein, we addressed the impact of IDH on mortality and other outcomes in patients with severe acute kidney injury (AKI) requiring intermittent hemodialysis.
Methods:
We retrospectively reviewed 1,009 patients who underwent intermittent hemodialysis due to severe AKI. IDH was defined as either dialysis discontinuation due to hemodynamic instability or a decrease in systolic blood pressure (BP) of ≥30 mmHg, with or without a nadir systolic BP of <90 mmHg during the first session. The primary outcome was all-cause mortality, and transfer to the intensive care unit (ICU) due to unstable status was additionally analyzed. Hazard ratios (HRs) of outcomes were calculated using a Cox regression model after adjusting for multiple variables. Risk factors for IDH were evaluated using a logistic regression model.
Results:
IDH occurred in 449 patients (44.5%) during the first hemodialysis session. Patients with IDH had a higher mortality rate than those without IDH (40% vs. 23%; HR, 1.30; 95% confidence interval [CI], 1.02–1.65). The rate of ICU transfer was higher in patients experiencing IDH than in those without IDH (17% vs. 11%; HR, 1.43; 95% CI, 1.02–2.02). Factors such as old age, high BP and pulse rate, active malignancy, cirrhosis, and hypoalbuminemia were associated with an increased risk of IDH episodes.
Conclusion
The occurrence of IDH is associated with worse outcomes in patients with AKI requiring intermittent hemodialysis. Therefore, careful monitoring and early intervention of IDH may be necessary in this patient subset.
6.Germline Mutations Related to Complete Remission After Neoadjuvant Chemotherapy in Patients With Triple-negative Breast Cancer
Jee Hyun AHN ; Ji Soo PARK ; Dongju WON ; Seung-Tae LEE ; Suk Jun LEE ; Seung Hye YANG ; Jee Ye KIM ; Seho PARK ; Seung Il KIM ; Byeong-Woo PARK ; Min Hwan KIM ; Gun Min KIM ; Joohyuk SOHN ; Hyung Seok PARK
Journal of Breast Cancer 2026;29(2):118-127
Purpose:
Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing.
Methods:
A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs.
Results:
The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066).
Conclusion
Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.
7.Posterior Lumbar Element Enforcement by Decompression Alone with Interspinous Fixation without Interbody Fusion for the Surgical Management of Lumbar Spondylolisthesis
Hyun-Woong PARK ; Moon-Soo HAN ; Ji-Ho JUNG ; Jong-Hwan HONG ; Shin-Seok LEE ; Jung-Kil LEE
Journal of Korean Neurosurgical Society 2025;68(2):150-158
Objective:
: In degenerative lumbar spondylolisthesis, interbody fusion surgery (IFS) has long been recommended as the gold standard of surgical management. However, IFS is less recommended for high-risk patients such as the elderly because it involves extensive surgery, with a long operation time and high volumes of blood loss, which lead to marked perioperative morbidity. We report an alternative primary and salvage treatment technique for high-risk lumbar spondylolisthesis through posterior lumbar element reinforcement using interspinous fixation and decompression alone without interbody fusion.
Methods:
: Plain radiographs, computed tomography scans, and magnetic resonance imaging, taken at different intervals, were used to measure local disc height (DH), vertebral body slippage (BS), and segmental motion angle (SMA). A Visual analogue scale and the Oswestry disability index (ODI) were applied pre-operation and at the last follow-up.
Results:
: The local SMA decreased significantly by 3.46°±3.07°, from 10.61°±3.42° preoperatively to 7.15±3.70 at the last follow-up (p<0.001). The DH decreased from 8.61±2.88 mm preoperatively to 8.41±2.48 mm at the last follow-up (p=0.074). The BS decreased from 3.49±4.29 mm preoperatively to 3.41±4.91 mm at the last follow-up (p=0.092). None of the patients reported worsening pain or an increased ODI after surgery, and there were no surgery-related complications.
Conclusion
: Posterior lumbar element reinforcement by decompression alone with SPIRE™ fixation is an alternative primary and salvage treatment option for select patients with spondylolisthesis.
8.Early Administration of Nelonemdaz May Improve the Stroke Outcomes in Patients With Acute Stroke
Jin Soo LEE ; Ji Sung LEE ; Seong Hwan AHN ; Hyun Goo KANG ; Tae-Jin SONG ; Dong-Ick SHIN ; Hee-Joon BAE ; Chang Hun KIM ; Sung Hyuk HEO ; Jae-Kwan CHA ; Yeong Bae LEE ; Eung Gyu KIM ; Man Seok PARK ; Hee-Kwon PARK ; Jinkwon KIM ; Sungwook YU ; Heejung MO ; Sung Il SOHN ; Jee Hyun KWON ; Jae Guk KIM ; Young Seo KIM ; Jay Chol CHOI ; Yang-Ha HWANG ; Keun Hwa JUNG ; Soo-Kyoung KIM ; Woo Keun SEO ; Jung Hwa SEO ; Joonsang YOO ; Jun Young CHANG ; Mooseok PARK ; Kyu Sun YUM ; Chun San AN ; Byoung Joo GWAG ; Dennis W. CHOI ; Ji Man HONG ; Sun U. KWON ;
Journal of Stroke 2025;27(2):279-283
9.A Survey of Korean Neurologists’ Awareness, Clinical Practice, Education, and Challenges in Sleep Medicine
Ki-Hwan JI ; Jung-Ick BYUN ; Dae Lim KOO ; Hyeyun KIM ; Hwan Seok PARK ; Jun Young LEE ; Sung Rae JO ; Ki-Young JUNG
Journal of the Korean Neurological Association 2025;43(1):21-27
Background:
Despite the critical importance of sleep medicine within neurology, notable gaps in education and clinical practice persist among neurologists. This study aims to explore the extent of involvement and the challenges faced by Korean neurologists in sleep medicine, focusing on awareness of polysomnography training program, the operation of sleep study facilities, and educational exposure.
Methods:
An online survey collected responses from 233 neurologists, focusing on their demographics, knowledge of and involvement in sleep medicine, operation of sleep study facilities, and participation in residency training.
Results:
The findings indicated that 84.9% of neurologists were aware of polysomnography training program, primarily through professional societies. Nonetheless, 15.1% reported unfamiliarity with these initiatives, with 72.7% of this subgroup expressing interest in sleep medicine yet lacking access to information. In terms of clinical practice, 74 neurologists operated sleep study facilities, with 63% intending to expand. Key operational challenges included staff management, maintaining patient volumes, and inadequate institutional support. Among respondents from teaching hospitals, only 36 out of 114 reported active resident involvement in sleep study interpretations, predominantly hindered by excessive workloads and insufficient staffing.
Conclusions
A significant number of neurologists have an interest in sleep medicine; however, substantial challenges impede effective education and clinical practice. These results underscore the need for improved educational resources and institutional support to enhance the growth and effectiveness of sleep medicine practices among neurologists.
10.Safety and Efficacy of Pivot-Balloon for Severe Tricuspid Regurgitation:The First-in-Man Experiences
Eun Kyoung KIM ; Min-Ku CHON ; Hyun-Sook KIM ; Yong-Hyun PARK ; Sang-Hyun LEE ; Ki Seok CHOO ; Hyung Gon JE ; Dae-Hee KIM ; Tae Oh KIM ; Yoon Seok KOH ; Jae-Hyeong PARK ; Jae-Hwan LEE ; Young Jin CHOI ; Eun Seok SHIN ; Hyuck-Jun YOON ; Seung-Whan LEE ; Joo-Yong HAHN
Korean Circulation Journal 2025;55(1):20-31
Background and Objectives:
Among various emerging catheter-based treatments for severe tricuspid regurgitation (TR), the spacer device can reduce the regurgitation orifice without manipulating the valve leaflet. However, its clinical application has been hampered by traumatic anchoring to the myocardium and the coaxial alignment of the balloon resulting in insufficient TR reduction. This study aimed to evaluate the early-stage safety, technical feasibility, and preliminary efficacy of the novel atraumatic vertical spacer in patients with isolated severe TR.
Methods:
All procedures were guided by fluoroscopy and transthoracic echocardiography.The maximum device placement time with an inflated balloon was 24 hours. Changes in the amount of TR, right ventricular function, and patient hemodynamics were measured during balloon deployment.
Results:
A total of 7 patients (median age 74), underwent successful device implantation without procedure-related complications. During balloon inflation (median 25 minutes), there were no symptoms or signs indicative of TR intolerance. TR was reduced by 1 grade or greater in all patients, with 2 patients exhibiting a reduction of 3 grades, from torrential TR to a moderate degree. Mild TR after balloon inflation was achieved in 3 patients with baseline severe TR. The TR reduction observed during initial balloon deployment was sustained during the subsequent balloon maintenance period.
Conclusions
The Pivot-balloon procedure was safe, technically feasible, and effective in reducing TR in patients with severe TR. No periprocedural complications or adverse cardiovascular events were reported during device placement with TR reduction observed in all patients. However, longer-term follow-up is needed to confirm safety and treatment effect.

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