Background: A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period. Methods: We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression. Results: Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated. Conclusion In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a global health issue due to its increasing prevalence associated with lifestyle changes and its strong correlation with metabolic syndrome. Farnesoid X receptor (FXR) is a nuclear receptor that plays a pivotal role in regulating bile acid, lipid, and glucose metabolism, making it an attractive therapeutic target for liver and metabolic diseases. In this study, we investigated the effects of MHY5456, a synthetic agonist of FXR, on hepatic metabolism and fibrosis. MHY5456 enhanced the transcriptional activity of FXR in a concentration-dependent manner.Treatment of AC2F rat liver-derived cells with MHY5456 resulted in the downregulation of genes involved in lipid accumulation and an upregulation of mitochondrial-related gene expression. Additionally, MHY5456 significantly reduced oleic acid (OA)-induced lipid accumulation. To assess its anti-fibrotic potential, we tested its effects on transforming growth factor-beta (TGF-β)-induced fibrosis in LX2 human hepatic stellate cells (HSCs). MHY5456 significantly suppressed the expression of fibrosis-related genes and proteins. In vivo, administration of MHY5456 to mice fed a methionine-choline-deficient (MCD) diet alleviated hepatic fibrosis, inflammation, and lipid accumulation. These results show that FXR activation by MHY5456 modulates lipid metabolism and fibrotic pathways, suggesting its potential as a pharmacological candidate for liver and metabolic disorders, including MASLD. Further pharmacological and toxicological studies are needed to confirm its therapeutic relevance.

Background: The aim of this study is to investigate the specific pathway involved in human leukocyte antigen (HLA) sensitization using single-cell RNA-sequencing analysis and an allo-sensitized mouse model developed with an HLA.A2 transgenic mouse. Methods: For sensitization, wild-type C57BL/6 mouse received two skin grafts from C57BL/6-Tg(HLA-A2.1)1Enge/J mouse (allogeneic mouse, ALLO). For syngeneic control (SYN), skin grafts were transferred from C57BL/6 to C57BL/6. We performed single-cell RNA-sequencing analysis on splenocytes isolated from ALLO and SYN and compared the gene expression between them. Results: We generated 9,190 and 8,890 single-cell transcriptomes from ALLO and SYN, respectively. Five major cell types (B cells, T cells, natural killer cells, macrophages, and neutrophils) and their transcriptome data were annotated according to the representative differentially expressed genes of each cell cluster. The percentage of B cells was higher in ALLO than it was in SYN. Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that the highly expressed genes in the B cells from ALLO were mainly associated with antigen processing and presentation pathways, allograft rejection, and the Th17 cell differentiation pathway. Upregulated genes in the T cells of ALLO were involved in the interleukin (IL)-17 signaling pathway. The ratio of Th17 cluster and Treg cluster was increased in the ALLO. On flow cytometry, the percentage of Th17 (IL-17+/CD4+ T) cells was higher and regulatory T cells (FOXP3+/CD4+ T) was lower in the ALLO compared to those in the SYN. Conclusion Our results indicate that not only the B cell lineage but also the Th17 cells and their cytokine (IL-17) are involved in the sensitization to HLA.

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases.This position paper focuses on the diagnosis and management of valvular heart diseases with referring to the guide‑ lines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee sought to reflect national data on the topic of valvular heart diseases published to date through a systematic literature search based on validity and relevance. In the part II of this article, we intend to pre‑ sent recommendations for diagnosis and treatment of mitral valve disease and tricuspid valve disease.

The worldwide incidence of precocious puberty, which is associated with negative health outcomes, is increasing. Several studies have suggested that environmental factors contribute to the development of precocious puberty alongside genetic factors. Some epidemiological studies have provided limited evidence suggesting an association between exposure to air pollution and changes in pubertal development. This systematic review aimed to summarize existing evidence on the association between air pollution exposure and precocious puberty. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, we searched two databases (PubMed and Web of Science) until August 2023. The included studies assessed the association between air pollutant exposure and the risk of precocious puberty, early menarche, or pubertal development. Two authors independently performed study selection and data extraction. A meta-analysis and analysis of the risk of bias were infeasible due to the limited number of studies and the heterogeneity among them. The literature search resulted in 184 studies, from which we included six studies with sample sizes ranging from 437 to 4,074 participants. The studies reported heterogeneous outcomes. Four studies found that increased exposure to air pollution was related to earlier pubertal onset. One study was inconclusive, and another suggested that air pollutant exposure may delay the onset of thelarche. Most studies suggest that exposure to air pollutants accelerates pubertal development; however, the results from the available studies are inconsistent. More extensive and well-designed longitudinal studies are required for a comprehensive understanding of the association between air pollution and precocious puberty.

We report a rare case of gastric adenocarcinoma with enteroblastic differentiation (GAED) that was treated with endoscopic submucosal dissection followed by additional distal gastrectomy with lymph node dissection. A 67-year-old man underwent endoscopic submucosal dissection for a gastric lesion, which was diagnosed as GAED with submucosal and lymphatic invasion. Histologically, GAED is characterized by a tubulopapillary growth pattern and clear cells that resemble those of the primitive fetal gut. Immunohistochemically, GAED variably expresses oncofetal proteins such as glypican-3, alpha-fetoprotein, and spalt-like transcription factor 4. Despite negative margins, additional gastrectomy with lymph node dissection was performed due to submucosal and lymphatic invasion.No residual tumor or metastasis was detected, and the patient remained disease-free for 2 years before dying from causes unrelated to GAED. Given its aggressive nature, frequent lymphovascular invasion, and high metastatic potential, clinicians should recognize the histopathological diagnosis of this rare tumor and its propensity for aggressiveness.

Signet-ring cell carcinoma (SRCC) is a rare tumor that most commonly occurs in the stomach. Duodenal SRCCs are extremely uncommon and account for approximately 1% of duodenal adenocarcinomas. Although Brunner’s gland hyperplasia (BGH) is a benign duodenal condition, studies have reported several cases of adenocarcinoma originating in an area of BGH. We report a rare case of early-stage SRCC originating in an area of BGH that was successfully treated using endoscopic mucosal resection. Based on the mucin phenotype observed in this case, it is reasonable to conclude that SRCC originated from gastric metaplasia in the area of BGH. Although BGH is a benign condition, careful evaluation is warranted for early detection of combined neoplasms.

Purpose: This study aimed to identify the etiology and risk factors of community-acquired pneumonia (CAP) requiring hospitalization in Korean children during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Clinical information of children admitted with CAP to Seoul National University Children’s Hospital (SNUCH) between January 1, 2021, and February 28, 2022, was retrospectively collected and analyzed. In addition, the etiologic diagnosis and demographic data of children with CAP who were discharged at the other seven hospitals between January and February 2022 were collected. Pneumonia was diagnosed using strict criteria comprising clinical symptoms, physical examination findings, and chest radiographic findings. Results: Among 91 children hospitalized with CAP at SNUCH during the 14-month period, 68.4% were aged <5 years and 79.1% had underlying diseases. Among the 95 CAP cases, respiratory assistance was required in 70.5%, and the use of a ventilator was required in 20.0%.A total of five patients expired, all of whom were either immunocompromised or had underlying neurological diseases. Neurological diseases and immunosuppression were significantly correlated with respiratory assistance (P=0.003) and death (P=0.014). A total of 55% of the detected respiratory pathogens were viruses, the most common of which was rhinovirus at 35.9%. Among the 169 children hospitalized for CAP at the eight institutions, ≥1 respiratory virus was detected in 92.3%, among which respiratory syncytial virus (79.8%) was the most prevalent. Conclusions Even during the COVID-19 pandemic, Korean children were hospitalized with CAP caused by seasonal respiratory viral pathogens. Although atypical and pyogenic bacteria were not detected, continuous clinical monitoring and further prospective studies should be conducted.

Purpose: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. Methods: This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. Results: In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. Conclusions Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)

Macrophage activation syndrome (MAS) is a fatal complication of adult-onset Still’s disease (AOSD). Although anti-cytokine agents have been recommended for refractory AOSD or complicated with MAS, MAS cases have been rarely reported during anticytokine treatment. Herein, we describe the first AOSD case complicated with MAS during the treatment with tocilizumab in Korea. Two years after tocilizumab maintenance therapy, high fever and hypertransaminasemia recurred. MAS was diagnosed based on hyperferritinemia, elevated soluble IL-2 receptor levels, and the presence of hemophagocytic histiocytes in the bone marrow.However, she had normal white blood cell counts and acute phase reactant levels. High-dose glucocorticoid and anakinra therapies were not effective, but her disease improved with etoposide. This case shows that tocilizumab may not prevent MAS development and can modify clinical features making it challenging to diagnose. Cytotoxic therapy such as etoposide may be required in MAS cases that develop during anti-cytokine therapy.