1,330 research outputs found
Admittance and noise in an electrically driven nano-structure: Interplay between quantum coherence and statistics
We investigate the interplay between the quantum coherence and statistics in
electrically driven nano-structures. We obtain expression for the admittance
and the current noise for a driven nano-capacitor in terms of the Floquet
scattering matrix and derive a non-equilibrium fluctuation-dissipation
relation. As an interplay between the quantum phase coherence and the many-body
correlation, the admittance has peak values whenever the noise power shows a
step as a function of near-by gate voltage.
Our theory is demonstrated by calculating the admittance and noise of driven
double quantum dots
BK polyomavirus-associated nephropathy
BK polyomavirus (BKPyV) is a ubiquitous virus residing in the kidney tubules and is clinically significant only in immunocompromised patients. In clinical practice, BKPyV is a causative pathogen of BKPyV-associated nephropathy (BKVAN) in kidney allograft recipients or hemorrhagic cystitis of hematopoietic stem cell transplant recipients. Currently, there is no effective treatment for BKVAN; therefore, careful monitoring and prudent modification of immunosuppression are necessary to prevent BKVAN. In this article, the epidemiology, pathophysiology, and current management strategies for BKVAN are reviewed
Biomarkers Predicting Treatment-Response in Nephrotic Syndrome of Children: A Systematic Review
Purpose Nephrotic syndrome (NS) is the most common form of glomerulopathy in children. Most pediatric patients respond to glucocorticosteroid treatment (steroid-sensitive NS, SSNS), while approximately 10–15% will remain unresponsive or later become steroid-resistant. There has been a long-standing effort to find biomarkers that may predict steroid responsiveness. Methods We systematically reviewed current studies which investigated clinically relevant biomarkers for predicting steroid responsiveness in pediatric NS. We performed a PubMed and EMBASE search to identify eligible articles. We collected data on urinary markers, blood/serum markers (including cellular phenotypes and mRNA expression), genotypes and HLA allele frequency. Results A total of 659 articles were identified following electronic and manual searches. After reviewing the titles, abstracts, and full texts, 72 eligible articles were finally included. Vitamin D-binding protein (VDBP) seemed to be significantly elevated in SRNS than in SSNS, in both serum and urine specimen, although further validation is required. Conclusions The present paper narratively illustrates current understandings of potential biomarkers that may help predict steroid responsiveness. Further investigation and collaboration involving a larger number of patients are necessary
Successful Salvage Unrelated Umbilical Cord Blood Transplantation with Two Units After Engraftment Failure with Single Unit in Severe Aplastic Anemia
Severe aplastic anemia (SAA) patients without an HLA-matched sibling donor need alternative treatment options. Umbilical cord blood transplantation (UCBT) has become an alternative means for treating various diseases, but it has not been proved to be a satisfactory method to treat SAA. Here, we report the case of a girl who underwent successful two-unit UCBT after engraftment failure with a single unit. Two-unit UCBT is proposed to have better engraftment potential and to offer a better chance of survival, according to some reports. Increased cell dose and graft-versus-graft reaction could contribute to these advantages. With this promising result, two-unit UCBT could be an alternative treatment option for patients with SAA without an HLA-matched donor
Risk Factors for the Progression of Chronic Kidney Disease in Children
Chronic kidney disease (CKD) in children is associated with various complications, including poor growth and development, mineral bone disorder, cardiovascular disease, kidney failure, and mortality. Slowing down the progression of CKD is important since CKD is often not curable. Prospective cohort studies have been conducted to understand the progression and outcomes of CKD in children, and these studies have identified non-modifiable and modifiable risk factors. Recognition of known risk factors and early intervention are important to delay the progression of kidney function decline in children
Genetic analysis using whole-exome sequencing in pediatric chronic kidney disease: a single center's experience
Purpose Chronic kidney disease (CKD) has various underlying causes in children. Identification of the underlying causes of CKD is important. Genetic causes comprise a significant proportion of pediatric CKD cases. Methods In this study, we performed whole-exome sequencing (WES) to identify genetic causes of pediatric CKD. From January to June 2021, WES was performed using samples from pediatric patients with CKD of unclear etiology. Results Genetic causes were investigated using WES in 37 patients (17 males) with pediatric CKD stages 1 (n=5), 2 (n=7), 3 (n=2), 4 (n=2), and 5 (n=21). The underlying diseases were focal segmental glomerulosclerosis (n=9), congenital anomalies of the kidney and urinary tract including reflux nephropathy (n=8), other glomerulopathies (n=7), unknown etiology (n=6), and others (n=7). WES identified genetic causes of CKD in 12 of the 37 patients (32.4%). Genetic defects were discovered in the COL4A4 (n=2), WT1 (n=2), ACTN4, CEP290, COL4A3, CUBN, GATA3, LAMA5, NUP107, and PAX2 genes. WT1 defects were found in patients whose pathologic diagnosis was membranoproliferative glomerulonephritis, and identification of CUBN defects led to discontinuation of immunosuppressive agents. Genetic diagnosis confirmed the clinical diagnosis of hypoparathyroidism, sensorineural deafness, and renal disease; Alport syndrome; and Joubert syndrome in three of the patients with CKD of unknown etiology (COL4A4 [n=2], CUBN [n=1]). Extrarenal symptoms were considered phenotypic presentations of WT1, PAX2, and CEP290 defects. Conclusions WES provided a genetic diagnosis that confirmed the clinical diagnosis in a significant proportion (32.4%) of patients with pediatric CKD
Vascular effects of estrogen in type II diabetic postmenopausal women
AbstractOBJECTIVESWe assessed the effects of estrogen on vascular dilatory and other homeostatic functions potentially affected by nitric oxide (NO)-potentiating properties in type II diabetic postmenopausal women.BACKGROUNDThere is a higher cardiovascular risk in diabetic women than in nondiabetic women. This would suggest that women with diabetes do not have the cardioprotection associated with estrogen.METHODSWe administered placebo or conjugated equine estrogen, 0.625 mg/day for 8 weeks, to 20 type II diabetic postmenopausal women in a randomized, double-blinded, placebo-controlled, cross-over design.RESULTSCompared with placebo, estrogen tended to lower low-density lipoprotein (LDL) cholesterol levels by 15 ± 23% (p = 0.007) and increase high-density lipoprotein (HDL) cholesterol levels by 8 ± 16% (p = 0.034). Thus, the ratio of LDL to HDL cholesterol levels significantly decreased with estrogen, by 20 ± 24%, as compared with placebo (p = 0.001). Compared with placebo, estrogen tended to increase triglyceride levels by 16 ± 48% and lower glycosylated hemoglobin levels by 3 ± 13% (p = 0.295 and p = 0.199, respectively). However, estrogen did not significantly improve the percent flow-mediated dilatory response to hyperemia (17 ± 75% vs. placebo; p = 0.501). The statistical power to accept our observation was 81.5%. Compared with placebo, estrogen did not significantly change E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 or matrix metalloproteinase-9 levels. Compared with placebo, estrogen tended to decrease tissue factor antigen and increase tissue factor activity levels by 7 ± 46% and 5 ± 34%, respectively (p = 0.321 and p = 0.117, respectively) and lower plasminogen activator inhibitor-1 levels by 16 ± 31% (p = 0.043).CONCLUSIONSThe effects of estrogen on endothelial, vascular dilatory and other homeostatic functions were less apparent in type II diabetic postmenopausal women, despite the beneficial effects of estrogen on lipoprotein levels
Retrospective Analysis of Peripheral Blood Stem Cell Transplantation for the Treatment of High-Risk Neuroblastoma
Disease relapse after autologous peripheral blood stem cell transplantation (APBSCT) is the main cause of treatment failure in high-risk neuroblastoma (NBL). To reduce relapse, various efforts have been made such as CD34+ selection and double APBSCT. Here the authors reviewed the clinical features and outcomes of high-risk NBL patients and analyzed their survival. The medical records of 36 patients with stage III or IV NBL who underwent APBSCT at Seoul National University Children's Hospital between May 1996 and May 2004 were reviewed. Total 46 APBSCTs were performed in 36 patients. Disease free survival (DFS) and overall survival of all patients were 47.7% and 68.8%, respectively. The patients were allocated to three groups according to the APBSCT type. The DFS of CD34+ non-selected single APBSCT patients (N=13), CD34+ selected single APBSCT patients (N=14), and CD34+ selected double APBSCT patients (N=9) were 55.6%, 40.6%, and 50.0%, respectively, which were not significantly different. Thus the survival was not found to be affected by CD34+ selection or transplantation number. To improve long-term survival, various efforts should be made such as chemotherapy dose intensification, more effective tumor purging, and control of minimal residual disease via the use of differentiating and immune-modulating agents
Successful mobilization using a combination of plerixafor and G-CSF in pediatric patients who failed previous chemomobilization with G-CSF alone and possible complications of the treatment
Peripheral blood stem cell (PBSC) mobilization, which uses plerixafor (AMD 3100), a newly developed specific inhibitor of the CXCR4 receptor, in combination with granulocyte-colony stimulating factor(G-CSF), has been shown to enhance the stem cell mobilization in adult patients, but pediatric data are scarce. We documented our experience with this drug in 6 Korean pediatric patients who had failed in chemomobilization, using G-CSF, alone. All patients were mobilized CD34+ cells (median, 11.08 × 106/kg: range, 6.34-28.97 × 106/kg) successfully within 2 to 3 cycles of apheresis, without complications. A total of 7 autologous transplantations were performed, including 1 tandem transplantation. However, 2 patients with brain tumors showed severe pulmonary complications, including spontaneous pneumomediastinum. This is the first study of PBSC mobilization with plerixafor in Asian pediatric patients. Furthermore our study suggests that mobilization with plerixafor may be effective in Korean pediatric patients, who have previously been heavily treated and have failed PBSC mobilization with classical chemomobilization, using G-CSF. However, further studies are needed to examine the possible complications of autologous transplantation, using a mobilized plerixafor product in children
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