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.Unique TTR Variants D38A and M13dup Among Korean Patients with Hereditary Transthyretin Amyloidosis:A Retrospective Single-Center Cohort Study
Min-Seung PARK ; Jae Joon LEE ; Darae KIM ; Jin-Oh CHOI ; Seok Jin KIM ; Kihyun KIM ; Ju-Hong MIN ; Hyun-Young KIM ; Hee-Jin KIM
Annals of Laboratory Medicine 2026;46(3):309-318
Background:
Transthyretin amyloidosis, a protein-misfolding disorder characterized by systemic amyloid deposition, can be classified as wild-type transthyretin amyloidosis (ATTRwt) or hereditary transthyretin amyloidosis (ATTRv), depending on the presence of transthyretin (TTR) gene variants. We examined the genetic distribution of TTR variants in Korean patients diagnosed with ATTRv.
Methods:
We retrospectively reviewed 801 participants who underwent TTR analysis at Samsung Medical Center from 2012 to 2024. The participants were categorized into two groups: in-house probands or relatives, and externally referred probands or relatives.
Results:
Pathogenic or likely pathogenic TTR variants were detected in 36 of 165 in-house probands (21.8%), among which D38A was the most frequent variant (50.0%; 18/36), followed by M13dup and E89K (8.3% each). Among referred probands, D38A was predominant (54.5%; 12/22), followed by M13dup (22.7%; 5/22). Cardiac amyloid involvement was the most common manifestation, observed in 97.2% (35/36) of in-house probands with ATTRv, followed by peripheral nervous system (PNS; 94.4%) and autonomic nervous system (ANS; 88.9%) involvement. In contrast, ANS involvement was most prevalent among in-house relatives who underwent organ evaluation (61.5%; 24/39), followed by cardiac (52.1%; 25/48) and PNS (48.7%; 19/39) involvement. Five of the eight in-house relatives harboring M13dup (62.5%) showed organ involvement, primarily in the ANS, supporting the pathogenicity of this variant.
Conclusions
This study provides the largest single-institution dataset of Korean patients with ATTRv, incorporating systematic organ assessments. The predominance of the unique TTR variants D38A and M13dup delineates a distinct genetic landscape that may facilitate accurate and timely diagnosis of ATTRv in the Korean population.
3.Defect Size-Based Comparative Analysis of Treatment Modalities for Esophagojejunal Anastomotic Leakage Following Gastrectomy
Ba Ool SEONG ; Ji Yong AHN ; Juno YOO ; Chang Seok KO ; Sa-Hong MIN ; Chung Sik GONG ; Beom Su KIM ; Moon-Won YOO ; Jeong Hwan YOOK ; Hee Jin CHOI ; In-Seob LEE
Journal of Gastric Cancer 2026;26(2):295-306
Purpose:
Esophagojejunal anastomotic leakage (EJAL) represents a severe postoperative complication following total or proximal gastrectomy. Treatment strategies include conservative management, endoscopic interventions, and surgery; however, comparative data remain limited. This study aimed to compare clinical outcomes of different strategies to identify the optimal approach based on anastomotic defect size.
Materials and Methods:
This retrospective study reviewed 100 patients diagnosed with EJAL between January 2015 and October 2024. Patients were categorized into four groups:conservative management, endoscopic vacuum-assisted closure (E-VAC), other endoscopic treatments, and surgery. The primary outcomes were leakage duration and length of hospital stay after EJAL diagnosis, whereas the secondary outcome was time to C-reactive protein normalization. Subgroup analyses were performed according to defect size.
Results:
Among the 100 patients, 76 were male and 24 were female, with a mean age of 65.7 years. Conservative treatment was the most common modality (53%), followed by other endoscopic treatments (19%), E-VAC (14%), and surgery (14%). In patients with a defect size <1 cm, conservative treatment was associated with significantly shorter leakage duration (P=0.035) and earlier resumption of diet (P=0.029) compared with endoscopic treatment.Among those with defects ≥2 cm, E-VAC demonstrated the most favorable median outcomes across all variables; however, statistical significance was not achieved because of the small sample size.
Conclusions
Conservative treatment appears to be the most effective treatment strategy for EJAL with anastomotic defects <1 cm. For larger defects (≥2 cm), E-VAC may offer clinical benefit, although further studies are needed to confirm its efficacy. These findings highlight the importance of individualized treatment selection based on defect size.
4.Prospective Evaluation of Irreversible Electroporation With Clustered Electrodes as a Novel Palliative Approach for Locally Advanced Pancreatic Cancer
Joon Ho KWON ; Man-Deuk KIM ; Maher Salamah ALANAZI ; Jiwon SUK ; Seung JEONG ; Seungmin BANG ; Moon Jae CHUNG ; Ho Kyoung HWANG ; Seung Soo HONG ; Kichang HAN ; Gyoung Min KIM ; Jong Yun WON ; Juil PARK ; Jaesung CHO ; Seok Min JEONG ; Tae Yang CHOI
Korean Journal of Radiology 2026;27(2):152-160
Objective:
This study aimed to evaluate the feasibility, safety, and oncologic outcomes of irreversible electroporation (IRE) using a clustered electrode in patients with locally advanced pancreatic cancer (LAPC).
Materials and Methods:
In this single-center prospective cohort study, 13 patients with LAPC (median age, 60 years; range, 48–78 years) underwent clustered electrode IRE between September 2022 and September 2024. Patient characteristics, procedural details, and clinical outcomes were recorded. Endpoints included technical success, procedure-related complications, overall survival (OS), and progression-free survival (PFS).
Results:
Tumors were located in the pancreatic head in four patients (30.8%) and in the body/tail in nine (69.2%). The median tumor size was 2.4 cm (1.5–4.0 cm), and vascular invasion was present in all patients. Technical success was achieved in all patients. Intraoperative IRE was performed in 11 (84.6%) patients, and 2 (15.4%) patients underwent percutaneous IRE. Gastrointestinal bleeding events as major complications occurred in two patients (15.4%) and, both were successfully controlled by embolization. No 60-day mortality was observed. At a median follow-up of 24.5 months (range, 9.9–33.4 months) after IRE, median OS and PFS from IRE were 20.1 and 14.5 months, respectively.
Conclusion
IRE using clustered electrodes for LAPC appears to be a feasible therapeutic approach, offering reliable technical success and acceptable safety. Survival outcomes are encouraging; however, larger, controlled studies are required.
5.Baricitinib for Itch-Dominant Atopic Dermatitis: A 52-week Baricitinib Real-World Experience in Korea
Narang HONG ; Ho Eun GWAG ; So Yun PARK ; Seok-Jae HEO ; Hye Jung JUNG ; Mi Youn PARK ; Yu Sung CHOI ; Jiyoung AHN
Annals of Dermatology 2026;38(3):183-190
Background:
Baricitinib is one of the front-runners among targeted agents for the treatment of atopic dermatitis (AD). Although many studies have been conducted on the real-world use of baricitinib, the sample size is often small and data is focused primarily on Caucasians.
Objective:
The objective of this study was to demonstrate the real-world itch-relieving property of baricitinib in adult AD patients in South Korea.
Methods:
Electronic medical records of AD patients treated with baricitinib at the National Medical Center in Korea from May 2021 to April 2023 were analyzed retrospectively.
Results:
Seventy patients completed 16 to 52 weeks of baricitinib treatment, with most patients showing mild-to-moderate baseline lesions and moderate-to-severe baseline itch. At Week 16 of baricitinib treatment, there was a 50% reduction in Itch numerical rating scale from baseline, and 50.7% of patients showed 50% improvement in Eczema Area and Severity Index score.The efficacy of baricitinib was also reflected in the patient reported outcomes, with 55%–58% improvements in Patient-Oriented Eczema Measure, Atopic Dermatitis Control Tool, and Dermatology Life Quality Index scores seen within 2 weeks of treatment. No new safety signals were detected in this study.
Conclusion
Baricitinib treatment for 52 weeks in Korean patients with itch dominant AD confirmed long term effectiveness and safety.
6.The Functional Study of Prostaglandin E2 via EP Receptor on Pacemaker Activity in Interstitial Cells of Cajal from Murine Colon
Hongyang GONG ; Han Yi JIAO ; Yuan CHANG ; Seok CHOI ; Chan Sik HONG ; Jae Yeoul JUN
Chonnam Medical Journal 2026;62(2):79-87
The interstitial cells of Cajal (ICC) generate spontaneous pacemaker activities responsible for producing slow waves in the gut smooth muscles. Prostaglandin E2 (PGE2 ) is one of the most important prostanoids in the gut, playing a crucial role in multiple physiological and pathological processes. Because information regarding the effects of PGE2 on colonic ICC is limited, we investigated the effects of PGE2 and its underlying signaling pathways in murine colonic ICC. Whole-cell patch-clamp recordings and reverse transcription polymerase chain reaction (RT-PCR) analyses were performed to evaluate the effects of PGE2 on mouse colonic ICC. PGE2 had a dual effect on pacemaker potential in the current-clamp mode. RT-PCR data suggested the expression of EP3 and EP4 receptors in colonic ICC. Low PGE2 concentrations induced membrane depolarization and generation of pacemaker activities. And this effect is mimicked by sulprostone (an EP3 agonist). The low PGE2 concentration-induced effect was inhibited by anoctamin-1 (ANO1) or a T-type Ca2+ channel blocker. Conversely, high PGE2 concentrations induced membrane hyperpolarization and blocked pacemaker potential generation. However, this inhibitory effect was blocked by an ATP-sensitive potassium (K ATP) channel blocker but not by other K+ channel blockers. Low concentrations of PGE2 activated EP3 receptors, leading to excitation of pacemaker activity through regulation of ANO1 and T-type Ca2+ channels in colonic ICC. In contrast, higher concentrations of PGE2 activated EP4 receptors and opened ATP-sensitive K+ channels, resulting in inhibition of pacemaker activity in colonic ICC.
7.Guideline for the Management of Obesity in Adult Patients With Obstructive Sleep Apnea
Soo-Kyoung PARK ; Yun Jin KANG ; Seung Hoon LEE ; Chan-Soon PARK ; Seok Jin HONG ; Ji Ho CHOI ; Jae Hoon CHO
Clinical and Experimental Otorhinolaryngology 2026;19(2):107-119
Objectives:
. Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder that is strongly influenced by obesity, the most important modifiable risk factor. Effective weight management is therefore essential for optimal OSA care. This guideline provides updated, evidence-based recommendations for the evaluation and management of obesity in adults with OSA, incorporating recent advances in lifestyle, pharmacologic, and surgical interventions.
Methods:
. The Korean Society of Sleep and Breathing convened a multidisciplinary panel. A systematic literature search was performed across major databases through 2025. Evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and recommendations were formulated by consensus using the Evidence-to-Decision framework.
Results:
. Eight statements were developed. Key recommendations include recognizing obesity as a major risk factor; routinely assessing overweight and obesity; and implementing structured weight reduction through diet, exercise, and behavioral therapy. Glucagon-like peptide-1 receptor agonists are recommended when lifestyle interventions are insufficient, and bariatric/metabolic surgery is advised for severe obesity unresponsive to nonsurgical treatment. Weight loss improves the apnea-hypopnea index, symptoms, and cardiometabolic markers and may reduce positive airway pressure needs. Continued follow-up is recommended even after clinical improvement.
Conclusion
. Weight management is a core component of OSA treatment. This guideline offers practical, evidence-based strategies to support clinicians in delivering effective, obesity-focused care for adults with OSA.
8.Bisphosphonates as a Tacrolimus-Sparing Strategy in Kidney Transplantation: Insights from a Retrospective Analysis
Hee Byung KOH ; Hyo Jeong KIM ; Ga Young HEO ; Namki HONG ; Yaeji LEE ; Seung Hwan SONG ; Hoon Young CHOI ; Chan-Young JUNG ; Hyung Woo KIM ; Jaeseok YANG ; Kyu Ha HUH ; Chung Mo NAM ; Beom Seok KIM
Yonsei Medical Journal 2026;67(1):17-26
Purpose:
Due to chronic toxicity, tacrolimus-sparing is an important issue in kidney transplant recipients (KTRs). Several studies have shown that bisphosphonate use is associated with favorable graft outcomes in KTRs. We investigated whether the association between tacrolimus trough levels (TTLs) and graft outcomes differed according to bisphosphonate use in KTRs.
Materials and Methods:
We conducted a retrospective study encompassing 1441 KTRs who were administered tacrolimus-based immunosuppressants. The primary exposure was a time-dependent cross-product of TTLs (low TTLs vs. normal-high TTLs with a reference of 6 ng/mL) and bisphosphonate use. Two primary outcomes were evaluated: overall graft loss (death or conversion to kidney replacement) and an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m 2 .
Results:
During the median follow-up of 6.1 (3.4–9.7) years, overall graft loss occurred in 157 (10.9%) patients. Cox regression revealed that normal-high TTLs without bisphosphonate use were associated with a reduced risk of overall graft loss [adjusted hazard ratio (aHR), 0.65; 95% confidence interval (CI), 0.45–0.95] compared to low TTLs without bisphosphonate use. The use of bisphosphonate in conjunction with normal-high TTLs correlated with an even lower risk of overall graft loss (aHR, 0.25; 95% CI, 0.08–0.80) compared with low TTLs without bisphosphonate use. In patients with low TTLs, bisphosphonate use was associated with a reduced risk of overall graft loss compared with non-use (aHR, 0.20; 95% CI, 0.09–0.43). Similar trends were observed in the eGFR outcome.
Conclusion
The use of bisphosphonate was associated with favorable graft outcomes, even with low TTLs. Incorporating bisphosphonate into a conventional immunosuppressant regimen may potentially reduce tacrolimus requirement.
9.Comparative survival outcomes of surgical resection versus radiotherapy after FOLFIRINOX in borderline resectable and locally advanced pancreatic cancer
Jiwon YU ; Jeong Ha LEE ; Hyunju SHIN ; Hee Chul PARK ; Joon Oh PARK ; Jung Yong HONG ; Minsuk KWON ; Ji Eun SHIN ; Kyu Taek LEE ; Kwang Hyuck LEE ; Jong Kyun LEE ; Joo Kyung PARK ; Young Hoon CHOI ; Jin Seok HEO ; In Woong HAN ; Sang Hyun SHIN ; Hongbeom KIM ; Ji Hye MIN ; Jeong Il YU
Precision and Future Medicine 2026;10(1):39-50
Purpose:
This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control.
Methods:
We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR.
Results:
Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37).
Conclusion
Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.
10.Effect of scan body geometric configuration and library design on digital implant impression accuracy
Hong Seok MOON ; Ahreum CHOI ; Kyung Chul OH ; Minji SUN ; Jaeyoung KIM
The Journal of Advanced Prosthodontics 2026;18(1):55-66
PURPOSE:
. The purpose of this in vitro study was to evaluate how variations in scan body geometry, specifically body height and the length of the flat indexing surface (FIS), affect linear and angular accuracy when combined with truncated or full-geometry library files.
MATERIALS AND METHODS:
. Nine scan body geometries were fabricated by combining three body heights (4, 5, and 6 mm) with three FIS lengths (1, 2, and 3 mm). Digital impressions were superimposed onto truncated or full-geometry library files. Linear deviation (ΔD) and angular deviation (ΔA) were calculated by comparing aligned scan bodies with coordinate measuring machine references. Linear and angular deviations were compared between library types using the Mann–Whitney U test, and differences among body heights and FIS lengths were evaluated using the Kruskal–Wallis test with Dunn’s post-hoc test (α = .05).
RESULTS:
. Linear deviation remained within a comparable range, and most geometry–library comparisons did not show a significant difference from body height, FIS length, or library morphology (P > .05). Angular deviation demonstrated geometry-dependent behavior, increasing only in the 4-mm body paired with larger FIS lengths, particularly when fullgeometry libraries were used. No significant angular differences were observed in the 5-mm or 6-mm body groups.
CONCLUSION
. Digital implant registration remained stable across most configurations. Shortened scan bodies performed reliably when FIS dimensions were preserved. Angular accuracy was more sensitive to geometry-library interactions, with truncated libraries improving stability.

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