Background: Endothelial cell (EC) dysfunction is a frequent feature in patients with end-stage renal disease (ESRD). The aim of this study was to generate human induced pluripotent stem cells, differentiate ECs (hiPSC-ECs) from patients with ESRD, and appraise the usefulness of hiPSC-ECs as a model to investigate EC dysfunction. Methods: We generated hiPSCs using peripheral blood mononuclear cells (PBMCs) isolated from three patients with ESRD and three healthy controls (HCs). Next, we differentiated hiPSC-ECs using the generated hiPSCs and assessed the expression of endothelial markers by immunofluorescence. The differentiation efficacy, EC dysfunction, and molecular signatures of EC-related genes based on microarray analysis were compared between the ESRD and HC groups. Results: In both groups, hiPSCs and hiPSC-ECs were successfully obtained based on induced pluripotent stem cell or EC marker expression in immunofluorescence and flow cytometry. However, the efficiency of differentiation of ECs from hiPSCs was lower in the ESRD-hiPSCs than in the HC-hiPSCs. In addition, unlike HC-hiPSC-ECs, ESRD-hiPSC-ECs failed to form interconnecting branching point networks in an in vitro tube formation assay. During microarray analysis, transcripts associated with oxidative stress and inflammation were upregulated and transcripts associated with vascular development and basement membrane extracellular matrix components were downregulated in ESRD-hiPSC-ECs relative to in HC-hiPSC-ECs. Conclusion ESRD-hiPSC-ECs showed a greater level of EC dysfunction than HC-hiPSC-ECs did based on functional assay results and molecular profiles. hiPSC-ECs may be used as a disease model to investigate the pathophysiology of EC dysfunction in ESRD.

Acanthamoeba spp. are free-living protozoa that are opportunistic pathogens for humans. Cysteine proteases of Acanthamoeba have been partially characterized, but their biochemical and functional properties are not clearly understood yet. In this study, we isolated a gene encoding cysteine protease of A. castellanii (AcCP) and its biochemical and functional properties were analyzed. Sequence analysis of AcCP suggests that this enzyme is a typical cathepsin L family cysteine protease, which shares similar structural characteristics with other cathepsin L-like enzymes. The recombinant AcCP showed enzymatic activity in acidic conditions with an optimum at pH 4.0. The recombinant enzyme effectively hydrolyzed human proteins including hemoglobin, albumin, immunoglobuins A and G, and fibronectin at acidic pH. AcCP mainly localized in lysosomal compartment and its expression was observed in both trophozoites and cysts. AcCP was also identified in cultured medium of A. castellanii. Considering to lysosomal localization, secretion or release by trophozoites and continuous expression in trophozoites and cysts, the enzyme could be a multifunctional enzyme that plays important biological functions for nutrition, development and pathogenicity of A. castellanii. These results also imply that AcCP can be a promising target for development of chemotherapeutic drug for Acanthamoeba infections.
Acanthamoeba castellanii ; Acanthamoeba ; Cathepsin L ; Cathepsins ; Cysteine Proteases ; Cysteine ; Fibronectins ; Genes, vif ; Humans ; Hydrogen-Ion Concentration ; Lysosomes ; Sequence Analysis ; Trophozoites ; Virulence

BACKGROUND/AIMS: Rebleeding is associated with mortality in patients with peptic ulcer bleeding (PUB), and risk stratification is important for the management of these patients. The purpose of our study was to examine the risk factors associated with rebleeding in patients with PUB. METHODS: The Korean Peptic Ulcer Bleeding registry is a large prospectively collected database of patients with PUB who were hospitalized between 2014 and 2015 at 28 medical centers in Korea. We examined the basic characteristics and clinical outcomes of patients in this registry. Univariate and multivariate analyses were performed to identify the factors associated with rebleeding. RESULTS: In total, 904 patients with PUB were registered, and 897 patients were analyzed. Rebleeding occurred in 7.1% of the patients (64), and the 30-day mortality was 1.0% (nine patients). According to the multivariate analysis, the risk factors for rebleeding were the presence of co-morbidities, use of multiple drugs, albumin levels, and hematemesis/hematochezia as initial presentations. CONCLUSIONS: The presence of co-morbidities, use of multiple drugs, albumin levels, and initial presentations with hematemesis/hematochezia can be indicators of rebleeding in patients with PUB. The wide use of proton pump inhibitors and prompt endoscopic interventions may explain the low incidence of rebleeding and low mortality rates in Korea.
Hemorrhage* ; Humans ; Incidence ; Korea ; Mortality ; Multivariate Analysis ; Peptic Ulcer Hemorrhage ; Peptic Ulcer* ; Prospective Studies ; Proton Pump Inhibitors ; Risk Factors

Operational tolerance (OT), defined as maintaining stable graft function without immunosuppression after transplant surgery, is an ideal goal for kidney transplant recipients (KTRs). Recent investigations have demonstrated the distinctive features of B cells, T cells, and dendritic cell-related gene signatures and the distributions of circulating lymphocytes in these patients; nonetheless, substantial heterogeneities exist across studies. This study was conducted to determine whether previously reported candidate gene biomarkers and the profiles of lymphocyte subsets of OT could be applied in Korean KTRs. Peripheral blood samples were collected from 153 patients, including 7 operationally tolerant patients. Quantitative real-time PCR and flow cytometry were performed to evaluate gene expression and lymphocyte subsets, respectively. Patients with OT showed significantly higher levels of B cell-related gene signatures (IGKV1D-13 and IGKV4-1), while T cell-related genes (TOAG-1) and dendritic cell-related genes (BNC2, KLF6, and CYP1B1) were not differentially expressed across groups. Lymphocyte subset analyses also revealed a higher proportion of immature B cells in this group. In contrast, the distributions of CD4⁺ T cells, CD8⁺ T cells, mature B cells, and memory B cells showed no differences across diagnostic groups. An OT signature, generated by the integration of IGKV1D-13, IGKV4-1, and immature B cells, effectively discriminated patients with OT from those in other diagnostic groups. Finally, the OT signature was observed among 5.6% of patients who had stable graft function for more than 10 years while on immunosuppression. In conclusion, we validated an association of B cells and their related signature with OT in Korean KTRs.
B-Lymphocytes ; Biomarkers ; Flow Cytometry ; Gene Expression ; Humans ; Immunosuppression ; Kidney Transplantation ; Kidney* ; Lymphocyte Subsets ; Lymphocytes ; Memory ; Precursor Cells, B-Lymphoid ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; T-Lymphocytes ; Transplant Recipients* ; Transplants

OBJECTIVE: A spinal cord subependymoma is an uncommon, indolent, benign spinal cord tumor. It is radiologically similar to a spinal cord ependymoma, but surgical findings and outcomes differ. Gross total resection of the tumor is not always feasible. The present study was done to determine the clinical, radiological and pathological characteristics of spinal cord subependymomas.METHODS: We retrospectively reviewed the medical records of ten spinal cord subependymoma patients (M : F=4 : 6; median 38 years; range, 21–77) from four institutions.RESULTS: The most common symptoms were sensory changes and/or pain in eight patients, followed by motor weakness in six. The median duration of symptoms was 9.5 months. Preoperative radiological diagnosis was ependymoma in seven and astrocytoma in three. The tumors were located eccentrically in six and were not enhanced in six. Gross total resection of the tumor was achieved in five patients, whereas subtotal or partial resection was inevitable in the other five patients due to a poor dissection plane. Adjuvant radiotherapy was performed in two patients. Neurological deterioration occurred in two patients; transient weakness in one after subtotal resection and permanent weakness after gross total resection in the other. Recurrence or regrowth of the tumor was not observed during the median 31.5 months follow-up period (range, 8–89).CONCLUSION: Spinal cord subependymoma should be considered when the tumor is located eccentrically and is not dissected easily from the spinal cord. Considering the rather indolent nature of spinal cord subependymomas, subtotal removal without the risk of neurological deficit is another option.
Astrocytoma ; Diagnosis ; Ependymoma ; Follow-Up Studies ; Glioma, Subependymal ; Humans ; Medical Records ; Radiotherapy, Adjuvant ; Recurrence ; Retrospective Studies ; Spinal Cord Neoplasms ; Spinal Cord ; Spine

OBJECTIVES: This study was conducted to investigate whether the charges associated with Korean Diagnosis-Related Groups for mental health inpatients adequately reflect the degree of medical resource consumption for inpatient treatment in the psychiatric ward. METHODS: This study was conducted with psychiatric inpatients data for 2014 from the National Health Insurance claim database. The main diagnoses required for admission, classification of the hospitals, and main treatment services were analyzed by examining descriptive statistics. Homogeneities of the major diagnostic criteria were assessed by calculating coefficient variances. Explanation power was determined by R2 values. RESULTS: The most frequent disorders for psychiatric inpatient treatment were alcohol-use disorder, depressive episodes, bipolar affective disorder, and dementia in Alzheimer's disease. Hospitalization and psychotherapy fees were the main medical expenses. Regardless of the homogeneity of the disease group, duration of hospital stay was the factor that most influenced medical expenses. In the psychiatric area, explanation power of Korean Diagnosis-Related Groups was 16.52% (p<0.05), which was significantly lower than that for other major diagnostic area. CONCLUSION: Most psychiatric illnesses are chronic, and the density of services can vary depending on illness severity or associated complications. The current Korean Diagnosis-Related Groups criteria did not adequately represent the amount of in-hospital medical expenditures. A novel Korean classification system that reflects the expenditures of medical resources in psychiatric hospitals should be developed in order to provide appropriate reimbursements.
Alzheimer Disease ; Classification ; Dementia ; Depressive Disorder ; Diagnosis ; Diagnosis-Related Groups* ; Fees and Charges ; Health Expenditures ; Hospital Charges* ; Hospitalization ; Hospitals, Psychiatric ; Humans ; Inpatients ; Insurance, Health ; Length of Stay ; Mental Health ; Mood Disorders ; National Health Programs ; Psychotherapy

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BACKGROUND: Screening for healthy blood donors through donor interviews is essential to the safety of donors and blood resources. Our goal was to suggest educational material for donor interviewers and donors, as well as supplemental material for interview sites, which will help provide an effective interview process. METHODS: We conducted surveys regarding experiences in donor interviews from donor interviewers and cognitive interviews about difficulties during interview from blood donors between September and October of 2015. We additionally conducted a post-survey about provided educational and supplemental materials between December 2015 and January 2016. RESULTS: The possibility of an incorrect answer in the donor history questionnaire (DHQ) was high for questions about sexual contact, imprisonment, or medication, and the reasons were incorrect memories, ignorance about donor interview, or protection of privacy. Cognitive interviews of donors revealed questions and terminology that are difficult to understand. Donor interviewers could obtain improved understanding of the DHQ through educational materials, which were found to be useful for new interviewers or donors. Use of a supplemental flip book for the interview process was found to be useful, especially for blood centers with small blood donations. CONCLUSION: This study investigated difficulties in the donor interview from the perspective of donor interviewers and donors and suggested educational and supplemental materials to address these difficulties. These materials will induce correct and honest answers from blood donors through education and guidance about the donor interview process and help secure the safety of blood products.
Blood Donors* ; Cognition ; Education ; Humans ; Mass Screening ; Privacy ; Tissue Donors*