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.

Myopia, particularly high myopia, is a significant risk factor for several ocular pathologies including cataract, glaucoma, and retinal detachment. Excessive axial elongation associated with high myopia can induce biomechanical stretching, increasing the risk of serious complications like posterior staphyloma and myopic maculopathy. Global meta-analyses estimate that approximately 10 million people were visually impaired due to myopic maculopathy in 2015, with 3 million being blind. Recent nationwide surveys in South Korea revealed a prevalence of 65.4% for myopia and 6.9% for high myopia in children and adolescents, highlighting the urgent need for effective management. Delaying the onset and slowing the progression of myopia during childhood and adolescence is crucial for reducing the potential lifetime risk of these complications. This consensus statement, prepared by the Korean Myopia Society for the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS), reviews the current evidence for myopia control interventions and provides management strategies applicable to the South Korean clinical setting. Key interventions covered include lifestyle modifications (outdoor time, near work adjustment), optical methods (myopia-control spectacle lenses, dual-focus soft contact lenses, orthokeratology), and pharmacologic treatment (low-concentration atropine), as well as combination therapies. The statement also addresses patient selection, treatment outcome evaluation using spherical equivalent and axial length changes, and the crucial aspects related to treatment cessation and the rebound effect.

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.

Background: Stem cell-based therapy is one of the tools for acute kidney injury (AKI) treatment. Tonsil tissue is a promising alternative source for the high-yield isolation of mesenchymal stem cells (MSCs). This study was undertaken to investigate the effects of tonsil-derived MSCs (T-MSCs) in animal model of AKI induced by gentamicin (GM). Methods: Twenty Sprague-Dawley rats were divided into four groups: Control, GM (70 mg/kg/day, intraperitoneal injection for 10 days), GM + T-MSCs (1 × 107 cells, intravenous injection at 1 day after the last vehicle/GM), and T-MSCs. Renal function, apoptosis, and markers of endoplasmic reticulum stress were measured on day 16 after the first vehicle/GM. Oxidative stress was assessed by measuring urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the expression of glutathione peroxidase (GPx) and catalase. Effects of T-MSCs on GM-induced apoptosis and oxidative stress in NRK cells were also evaluated using a co-culture technique of NRK cells and T-MSC. Results: In the GM + T-MSCs group, blood urea nitrogen, creatinine, and tubular damage score were lower compared to the GM group. T-MSCs injection decreased apoptotic cells and the expression of Bax, cytochrome c, and cleaved caspase and increased Bcl-2. T-MSC injection decreased urinary 8-OHdG and increased expression of GPx and catalase in the kidneys. Anti-human nuclei and PKH26 staining demonstrated the localization of T-MSCs in the tubules of renal cortex. In-vitro study revealed that T-MSCs or T-MSC-conditioned media ameliorated GM-induced nicotinamide adenine dinucleotide phosphate oxidase-1 expression, hydrogen peroxide generation, and apoptosis of NRK cells. Conclusion Our study demonstrated that T-MSCs ameliorated GM-induced AKI by directly incorporating into the damaged renal tubules and exerting antiapoptotic and antioxidative effects.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily affecting children, typically presenting as self-limiting skin lesions. However, extracutaneous JXG (extra-JXG) or systemic JXG (sJXG) can involve various organs, including the central nervous system (CNS), leading to high morbidity and mortality, especially in cases of CNS involvement. Treatment approaches for CNS–JXG, including surgical resection, chemotherapy, and radiation therapy, lack consensus, with reports of relapsed or refractory cases being rare. Here, we present the case of a 2-year-old girl with refractory extra-JXG involving the CNS, characterized by multiple intracranial lesions.Initial chemotherapy with prednisolone and vinblastine showed no response, and second-line therapy, including cytarabine and vincristine combined with surgical resection, was also ineffective. However, a 6-cycle third-line chemotherapy regimen incorporating vincristine and carboplatin led to a positive response, with stable disease status, and normal growth and neurodevelopment observed. Our findings suggest that combined chemotherapy with carboplatin and vincristine is a feasible and well-tolerated treatment strategy for patients with CNS–JXG.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily affecting children, typically presenting as self-limiting skin lesions. However, extracutaneous JXG (extra-JXG) or systemic JXG (sJXG) can involve various organs, including the central nervous system (CNS), leading to high morbidity and mortality, especially in cases of CNS involvement. Treatment approaches for CNS–JXG, including surgical resection, chemotherapy, and radiation therapy, lack consensus, with reports of relapsed or refractory cases being rare. Here, we present the case of a 2-year-old girl with refractory extra-JXG involving the CNS, characterized by multiple intracranial lesions.Initial chemotherapy with prednisolone and vinblastine showed no response, and second-line therapy, including cytarabine and vincristine combined with surgical resection, was also ineffective. However, a 6-cycle third-line chemotherapy regimen incorporating vincristine and carboplatin led to a positive response, with stable disease status, and normal growth and neurodevelopment observed. Our findings suggest that combined chemotherapy with carboplatin and vincristine is a feasible and well-tolerated treatment strategy for patients with CNS–JXG.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily affecting children, typically presenting as self-limiting skin lesions. However, extracutaneous JXG (extra-JXG) or systemic JXG (sJXG) can involve various organs, including the central nervous system (CNS), leading to high morbidity and mortality, especially in cases of CNS involvement. Treatment approaches for CNS–JXG, including surgical resection, chemotherapy, and radiation therapy, lack consensus, with reports of relapsed or refractory cases being rare. Here, we present the case of a 2-year-old girl with refractory extra-JXG involving the CNS, characterized by multiple intracranial lesions.Initial chemotherapy with prednisolone and vinblastine showed no response, and second-line therapy, including cytarabine and vincristine combined with surgical resection, was also ineffective. However, a 6-cycle third-line chemotherapy regimen incorporating vincristine and carboplatin led to a positive response, with stable disease status, and normal growth and neurodevelopment observed. Our findings suggest that combined chemotherapy with carboplatin and vincristine is a feasible and well-tolerated treatment strategy for patients with CNS–JXG.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily affecting children, typically presenting as self-limiting skin lesions. However, extracutaneous JXG (extra-JXG) or systemic JXG (sJXG) can involve various organs, including the central nervous system (CNS), leading to high morbidity and mortality, especially in cases of CNS involvement. Treatment approaches for CNS–JXG, including surgical resection, chemotherapy, and radiation therapy, lack consensus, with reports of relapsed or refractory cases being rare. Here, we present the case of a 2-year-old girl with refractory extra-JXG involving the CNS, characterized by multiple intracranial lesions.Initial chemotherapy with prednisolone and vinblastine showed no response, and second-line therapy, including cytarabine and vincristine combined with surgical resection, was also ineffective. However, a 6-cycle third-line chemotherapy regimen incorporating vincristine and carboplatin led to a positive response, with stable disease status, and normal growth and neurodevelopment observed. Our findings suggest that combined chemotherapy with carboplatin and vincristine is a feasible and well-tolerated treatment strategy for patients with CNS–JXG.

Purpose: A “Smart Cancer Care” platform that integrates patient-reported outcomes (PROs) with management has been established in Korea. This study focused on improving health behaviors and connecting patients to welfare services by introducing and assessing the feasibility of “Smart Cancer Care 2.0,” an enhanced version designed for monitoring complications post-cancer treatment. Materials and Methods: Smart Cancer Care 2.0 was developed by conducting a literature review and consulting with expert panels to identify symptoms or variables requiring monitoring and management guidelines based on the treatment type. Qualitative and quantitative surveys were conducted to assess the feasibility of the app and web system based on the experiences of patients with cancer and healthcare workers. Results: A total of 81 symptoms or variables (chemotherapy-, surgery-, radiotherapy-, rehabilitation-, and health management-related) were selected for management in Smart Cancer Care 2.0. PROs for these symptoms were basically categorized into three severity grades: preventive management, self-treatment, and consultation with a healthcare worker or visit to a healthcare institution. The overall mean scores in the feasibility evaluation by patients and healthcare workers were 3.83 and 3.90 points, respectively, indicating high usefulness. Conclusion Smart Cancer Care 2.0 leverages the existing information and communication technologies–based platform, Smart Cancer Care, and further includes health behaviors and welfare services. Smart Cancer Care 2.0 may play a crucial role in establishing a comprehensive post-discharge management system for patients with cancer as it provides suitable interventions based on patients’ responses and allows the regularly collected PROs to be easily viewed for streamlined care.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.