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.Solitary fibrous tumor: an updated review
Journal of Pathology and Translational Medicine 2026;60(1):20-46
Solitary fibrous tumor (SFT) is a fibroblastic neoplasm characterized by a branching, thin-walled dilated staghorn-shaped (hemangiopericytoma-like) vasculature and a NAB2::STAT6 gene fusion. SFTs can occur in almost any anatomical location, including superficial and deep soft tissues, visceral organs, and bone. They most commonly occur in extrapleural locations, equally affect both sexes, and are typically present in adults. Although metastasis is rare, SFTs frequently show local recurrence. The diagnosis of SFTs is difficult because of their broad histological and morphological overlap with other neoplasms. An accurate diagnosis is important for guiding disease management and prognosis. Despite advances in molecular diagnostics and therapeutic strategies, the biological complexity and unpredictable clinical behavior of SFTs present significant challenges. This review provides an updated overview of SFT, with a focus on its molecular genetics, histopathological features, and diagnostic considerations.
3.Cutaneous soft tissue tumors in the 5th edition of the World Health Organization classification of skin tumors: key updates and new entities
Journal of Pathology and Translational Medicine 2026;60(2):144-183
The 5th edition of the World Health Organization (WHO) classification of skin tumors introduces a dedicated chapter on cutaneous soft tissue tumors, providing a comprehensive, standardized reference with updated diagnostic criteria that directly inform routine dermatopathology practice and molecular diagnostics. This edition incorporates several key changes, including newly recognized entities such as EWSR1::SMAD3-rearranged fibroblastic tumor, neurotrophic tyrosine receptor kinase (NTRK)–rearranged spindle cell neoplasm, superficial CD34-positive fibroblastic tumor, and CRTC1::TRIM11 cutaneous tumor. Diagnostic terminology has also been refined; for example, the term ‘atypical intradermal smooth muscle neoplasm’ replaces ‘cutaneous leiomyosarcoma’ for lesions confined to the dermis, whereas the designation leiomyosarcoma is reserved for tumors with overt subcutaneous infiltration. In addition, epithelioid fibrous histiocytoma has been reassigned to the family of tumors of uncertain differentiation. This review summarizes the key updates and newly recognized entities in the chapter on cutaneous soft tissue tumors in the 5th edition of the WHO classification of skin tumors, emphasizing their clinicopathological and molecular implications.
4.Pluviatolide Attenuates Type I Hypersensitivity through Regulation of Mast Cell Activation
Seon Young KIM ; Jeong Won PARK ; Juhyun SHIN ; Ji-Ae LEE ; Sun-Hee LEEM ; Min Geun JO ; Min Yeong CHOI ; Wahn Soo CHOI ; Keun Young MIN ; Geunwoong NOH ; Sung-Jin BAE ; Yung Hyun CHOI ; Hyuk Soon KIM
Biomolecules & Therapeutics 2026;34(2):413-422
This study examined the inhibitory effects of pluviatolide, a lignan derived from Podophyllum hexandrum, on mast cell activation and IgE-mediated type I hypersensitivity, focusing on FcεRI-dependent and calcium-mediated pathways. Using bone marrowderived mast cells (BMMCs) and rat basophilic leukemia (RBL)-2H3 cells, we found that pluviatolide significantly decreased β-hexosaminidase release and suppressed the expression and secretion of TNF-α and IL-6 in a concentration-dependent manner, without causing cytotoxicity. While we initially hypothesized that it would selectively modulate antigen-specific FcεRI signaling, pluviatolide also inhibited degranulation induced by calcium ionophore and thapsigargin, indicating its effects extend to receptorindependent, Ca2+-dependent activation mechanisms. Immunoblot analyses revealed decreased phosphorylation of proximal kinases (Lyn, Syk), adaptor proteins (LAT, PLCγ1), MAPKs (ERK1/2, JNK, p38), and NF-κB p65. In a passive cutaneous anaphylaxis (PCA) mouse model, oral administration of pluviatolide significantly reduced Evans blue extravasation and mast cell degranulation in ear tissues. These findings demonstrate that pluviatolide suppresses both early and late-phase mast cell responses through multi-nodal inhibition of activation pathways, highlighting its potential as a therapeutic candidate for both IgE-mediated and non-IgE-mediated allergic disorders.
5.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
6.Superiorly based nasolabial flap for closure of oronasal fistula:a case report
Ji-Eun CHOI ; Hyuk-Jun MOON ; Jin-Wook KIM ; Gyu-Jo SHIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2026;52(2):94-99
Oronasal fistula (ONF) is an epithelialized tract between the oral and nasal cavities, for which various flaps are used in surgical closure. ONF may lead to regurgitation of food into the nasal cavity, nasal obstruction, halitosis, and other symptoms that contribute to patient discomfort and impaired quality of life. Surgical closure is challenging, occasionally requiring multiple procedures and carrying a risk of recurrence. The nasolabial flap (NLF) is a well-established local flap for soft tissue reconstruction in the orofacial region; superiorly based flaps are typically used for defects of the nasal dorsum, tip, and ala, while inferiorly based flaps are applied to defects of the nasal floor, lips, and buccal mucosa. The NLF provides dependable vascularity and favorable donor-site esthetic outcomes. Although superiorly based NLFs are not commonly used for intraoral reconstruction, this case report suggests that they can serve as a feasible option for ONF closure in carefully selected patients when the flap lies within an appropriate distance from the maxilla.
7.Changes in pulse wave transit time variability after interscalene brachial plexus block placement
Eun Joo CHOI ; Jung A LIM ; Chang Hyuk CHOI ; Dong Hyuck KIM ; Sungbin JO ; Jonghae KIM
Korean Journal of Anesthesiology 2026;79(1):82-94
Background:
The pulse wave transit time (PWTT) increases with decreased vascular tone resulting from sympathetic blockade caused by regional anesthesia. It oscillates, exhibiting variability due to the interaction between the autonomic nervous and cardiovascular systems. We hypothesized that interscalene brachial plexus block (ISBPB) placement increases the PWTT and reduces the low-frequency power of PWTT variability (LF).
Methods:
Fifty-six patients receiving an ISBPB were analyzed. The PWTT was defined as the difference in milliseconds (ms) between the R peak of the electrocardiogram and the peak of the second-derivative photoplethysmographic waveform. The LF was calculated by integrating from 0.04 to 0.15 Hz on the power spectrum obtained from fast Fourier transform. The two variables were collected during the 5 min before the end of acclimatization (baseline), between 5 and 10 min after block needle insertion, and between 15 and 20 min after block needle insertion.
Results:
The PWTT increased significantly (P < 0.001) from baseline (mean [SD]: 155.3 [16.7] ms) to 5–10 min post-needle insertion (166.9 [15.4] ms) (mean difference [MD]: 11.6, 95% CI [9.2–14.0], P < 0.001) and 15–20 min post-needle insertion (165.6 [16.1] ms) (MD: 10.3, 95% CI [7.3–13.2], P < 0.001). The natural log-transformed LF (lnLF) decreased significantly (P < 0.01) from baseline (1.539 [0.560] ln[ms2/Hz]) to 5–10 min post-needle insertion (1.341 [0.617] ln[ms2/Hz]) (MD: –0.198, 95% CI [–0.356 to –0.040], P < 0.01) and 15–20 min post-needle insertion (1.396 [0.548] ln[ms2/Hz]) (MD: –0.144, 95% CI [–0.274 to –0.013], P = 0.03).
Conclusions
The post-ISBPB decrease in lnLF and increase in PWTT may be attributable to ISBPB-induced sympathectomy.
8.Successful Treatment of Gastrointestinal Polyposis-Related Iron Deficiency Anemia and Hypoalbuminemia with Sirolimus in Bannayan–Riley–Ruvalcaba Syndrome
Sumin YOO ; Ho Jung CHOI ; In Hyuk YOO
Clinical Pediatric Hematology-Oncology 2026;33(1):51-56
Refractory iron deficiency anemia (IDA) in children should be investigated beyond dietary deficiency, particularly when accompanied by growth faltering or hypoalbuminemia. PTEN hamartoma tumor syndrome, which includes the Bannayan–Riley– Ruvalcaba syndrome (BRRS) spectrum, may cause diffuse gastrointestinal polyposis, resulting in chronic occult blood and protein loss. We report the case of a girl born in 2015 who presented at the age of two years with severe IDA (hemoglobin 5.0 g/dL, mean corpuscular volume 53.6 fL). Oral iron therapy was initiated, followed by intermittent intravenous iron infusions at progressively shorter intervals; however, the anemia recurred. Stool occult blood and fecal calprotectin test results were consistently negative during this period. Endoscopy and capsule endoscopy revealed diffuse gastrointestinal polyposis, including numerous small bowel polyps with ulcerative features. Genetic analysis revealed a heterozygous pathogenic variant in PTEN, NM_000314.8:c.389G>A (p.Arg130Gln). Despite endoscopic polypectomy and oral nutritional supplementation, IDA, hypoalbuminemia (albumin, 2.5-3.2 g/dL), and growth faltering persisted. Extraintestinal findings included macrocephaly, lipomatous masses, a subcutaneous hamartoma, and brain magnetic resonance imaging findings consistent with BRRS. Sirolimus therapy was initiated in September 2025, targeting a trough level of 6-10 ng/mL. By 6 months, hemoglobin stabilized at 12.9 g/dL, albumin normalized to 4.4 g/dL, weight increased by 5.1 kg, body mass index improved from below the 3rd percentile to the 10th percentile, and intravenous iron was no longer required. This case suggests that sirolimus may be beneficial in the treatment of diffuse PTEN-related gastrointestinal polyposis when endoscopic management is insufficient.
9.Spinal Needle-Guided Arthroscopic Transosseous Repair for Bony Bankart Lesions
Dongju SHIN ; Sung Hyuk PARK ; Kyoung Hwan KOH ; Sung CHOI
Clinics in Orthopedic Surgery 2026;18(1):184-188
Bony Bankart lesions present considerable challenges in shoulder surgery, particularly when large. While smaller lesions can often be treated effectively using the single-row technique, larger lesions require more complex approaches. Several arthroscopic techniques have been developed to manage these lesions. Although the double-row technique is effective, it has the disadvantage of placing suture material on the articular surface. In contrast, the transosseous technique permits adequate compression and surface contact without involving the articular surface; however, it is technically demanding and frequently requires specialized instruments. This technical note describes a simplified arthroscopic transosseous repair method for bony Bankart lesions using standard spinal needles and Kirschner wires, eliminating the need for specialized equipment while ensuring secure fixation and optimal surface contact.
10.The Clinical Effect of Trochlear Dysplasia on Medial Patellofemoral Ligament Reconstruction:Supratrochlear Spur and Lateral Inclination
Jin-Gyu KIM ; Junwoo BYUN ; Min JUNG ; Kwangho CHUNG ; Hyun-Soo MOON ; Se-Han JUNG ; Chong-Hyuk CHOI ; Sung-Hwan KIM
Clinics in Orthopedic Surgery 2026;18(1):52-62
Background:
The Dejour classification is widely accepted for grading the severity of trochlear dysplasia. However, whether it serves as a reliable prognostic marker for patellar instability surgery or a guide for clinical decision-making has yet to be established. Medial patellofemoral ligament (MPFL) reconstruction, with or without tibial tubercle osteotomy (TTO), yields comparable outcomes across Dejour grades. Nonetheless, we hypothesized that specific trochlear parameters would be more significant predictors of surgical results.
Methods:
This study included patients who underwent MPFL reconstruction, with or without TTO, for recurrent patellar dislocation at a single institution between 2010 and 2023. Patients with at least 1 year of follow-up were included. Preoperative demographics, radiographic measurements such as sulcus angle, lateral trochlear inclination (LTI), and trochlear depth, patient-reported outcome measures (PROMs), and intraoperative findings including cartilage status were analyzed. Severe trochlear dysplasia (STD) was categorized as Dejour B/D, while non-STD encompassed all other cases, and these 2 groups were compared. Postoperative PROMs were assessed at 1 year postoperatively and at the final follow-up. A noninferiority test was performed using Kujala, Lysholm, and International Knee Documentation Committee (IKDC) scores, with the inferiority margin defined by the minimal clinically important difference (MCID). Linear relationships between LTI, a widely used indicator of trochleoplasty, and PROMs were evaluated. Additionally, differences in the proportion of patients achieving MCID, substantial clinical benefit, and patient-acceptable symptom state were analyzed using odds ratios.
Results:
Forty-two knees (41 patients) were finally enrolled. Radiographic measurements, except for LTI at the most proximal trochlea, showed no significant differences between the STD and non-STD groups. Clinical outcomes also demonstrated no significant differences between the 2 groups, and noninferiority was confirmed. When analyzed based on LTI, no differences in PROMs were observed at the postoperative 1 year. However, at the final follow-up (mean, 37.27 months), the most proximal trochlear LTI showed significant correlations with both Kujala and Knee Injury and Osteoarthritis Outcome Score over the follow-up period.
Conclusions
MPFL reconstruction, with or without TTO, leads to similar clinical improvements for STD classified by Dejour criteria. However, when assessed using proximal LTI, dysplasia’s role as a prognostic factor should be considered.

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