910 research outputs found

    TRPV1 protects renal ischemia-reperfusion injury in diet-induced obese mice by enhancing CGRP release and increasing renal blood flow

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    Background Obesity is a major risk factor for end-stage renal disease. Using transient receptor potential vanilloid 1 knockout (TRPV1−/−) mice, we tested the hypothesis that TRPV1 protects against obesity-induced exacerbation of renal ischemia-reperfusion (I/R) injury. Methods TRPV1−/− and wild-type (WT) mice were fed a chow or Western diet (WD) for 22–23 weeks. After that, mice were subjected to renal I/R injury, and renal cortical blood flow (CBF) and medullary blood flow (MBF) were measured. Results The Western diet significantly increased body weight and fasting blood glucose levels in both TRPV1−/− and WT mice. WD-induced impairment of glucose tolerance was worsened in TRPV1−/− mice compared with WT mice. WD intake prolonged the time required to reach peak reperfusion in the cortex and medulla (both P < 0.05), decreased the recovery rate of CBF (P < 0.05) and MBF (P < 0.05), and increased blood urea nitrogen, plasma creatinine, and urinary 8-isoprostane levels after I/R in both mouse strains, with greater effects in TRPV1−/− mice (all P < 0.05). Renal I/R increased calcitonin gene-related peptide (CGRP) release in WT but not in TRPV1−/− mice, and WD attenuated CGRP release in WT mice. Moreover, blockade of CGRP receptors impaired renal regional blood flow and renal function in renal I/R injured WT mice. Conclusion These results indicate that TRPV1 plays a protective role in WD-induced exacerbation of renal I/R injury probably through enhancing CGRP release and increasing renal blood flow

    Activation of TRPV1 Prevents Salt-Induced Kidney Damage and Hypertension After Renal Ischemia-Reperfusion Injury in Rats

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    Background/Aims: High-salt intake after recovery from renal ischemia-reperfusion (I/R) injury leads to hypertension with severe renal damage. Transient receptor potential vanilloid type 1 (TRPV1) channels have been involved in the regulation of inflammation and oxidative stress following ischemic organ injury. We tested the hypothesis that activation of TRPV1 conveys preconditioning protection to the kidney subjected to I/R. Methods: TRPV1 was activated or down-regulated by subcutaneous injection of a low (1mg/kg) or high (100mg/kg) dose of capsaicin, respectively, 3 hours before ischemia. Rats were fed a 0.4% NaCl diet for 5 weeks after I/R followed by a 4% NaCl diet for 4 more weeks in 4 groups: sham, I/R, I/R+high-dose capsaicin (HCap), and I/R+low-dose capsaicin (LCap). Results: Renal TRPV1 expression was decreased in I/R rats (P&#x3c; 0.05) and further reduced in I/R+HCap group (P&#x3c; 0.05) but unchanged in I/R+LCap rats compared with the sham group. Blood pressure were elevated in I/R rats (P&#x3c; 0.05) and further increased in I/R+HCap group (P&#x3c; 0.05) but unchanged in I/R+LCap rats compared with sham. Renal function was impaired in I/R rats (P&#x3c; 0.05) and further deteriorated in I/R+HCap group (P&#x3c; 0.05) but unchanged in I/R+LCap group. Renal inflammatory responses, oxidative stress, and renal collagen deposition were augmented in I/R rats (all P&#x3c; 0.05) and further intensified in I/R+HCap group (all P&#x3c; 0.05) but unchanged in I/R+LCap group. Conclusion: Activation of TRPV1 plays an anti-inflammatory and anti-oxidative stress role in preventing renal tissue damage and salt-induced hypertension after I/R injury, indicating that TRPV1 conveys preconditioning protection that may have therapeutic implication

    Mentoring in Literacy Education: A Commentary from Graduate Students, Untenured Professors, and Tenured Professors

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    This commentary continues a dialogue which began among literacy teacher educators attending an alternative format session about mentoring in the academy at a national conference. Literacy teacher educators participated in an informal discussion centered on the nature of mentoring in the academy for doctoral students, untenured professors, and tenured professors. Doctoral students focused on their changing identities and roles in the academy, their concerns about navigating the political infrastructure of academia, and the importance of assuming a proactive stance towards obtaining mentoring, especially for part-time doctoral students. Untenured professors focused on the ways they were inventing and reinventing themselves within the power and politics of academia and their need for more holistic mentoring during these turbulent times. Tenured professors were able to embed mentoring experiences into their scholarly work and find ways to benefit or learn from mentoring experiences. These mentors also found comfort in more informal mentoring that included self-initiated endeavors centered on mutual interests. Our commentary draws on these discussions as well as the professional literature on mentoring to describe the importance of mutual trust and reciprocity in mentoring throughout all stages of academia with attention to cultural and linguistic diversity

    Identification of PKD1L1 Gene Variants in Children with the Biliary Atresia Splenic Malformation Syndrome

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    Biliary atresia (BA) is the most common cause of end‐stage liver disease in children and the primary indication for pediatric liver transplantation, yet underlying etiologies remain unknown. Approximately 10% of infants affected by BA exhibit various laterality defects (heterotaxy) including splenic abnormalities and complex cardiac malformations — a distinctive subgroup commonly referred to as the biliary atresia splenic malformation (BASM) syndrome. We hypothesized that genetic factors linking laterality features with the etiopathogenesis of BA in BASM patients could be identified through whole exome sequencing (WES) of an affected cohort. DNA specimens from 67 BASM subjects, including 58 patient‐parent trios, from the NIDDK‐supported Childhood Liver Disease Research Network (ChiLDReN) underwent WES. Candidate gene variants derived from a pre‐specified set of 2,016 genes associated with ciliary dysgenesis and/or dysfunction or cholestasis were prioritized according to pathogenicity, population frequency, and mode of inheritance. Five BASM subjects harbored rare and potentially deleterious bi‐allelic variants in polycystin 1‐like 1, PKD1L1, a gene associated with ciliary calcium signaling and embryonic laterality determination in fish, mice and humans. Heterozygous PKD1L1 variants were found in 3 additional subjects. Immunohistochemical analysis of liver from the one BASM subject available revealed decreased PKD1L1 expression in bile duct epithelium when compared to normal livers and livers affected by other non‐cholestatic diseases. Conclusion WES identified bi‐allelic and heterozygous PKD1L1 variants of interest in 8 BASM subjects from the ChiLDReN dataset. The dual roles for PKD1L1 in laterality determination and ciliary function suggest that PKD1L1 is a new, biologically plausible, cholangiocyte‐expressed candidate gene for the BASM syndrome

    Arsenic Trioxide with Ascorbic Acid and High-Dose Melphalan: Results of a Phase II Randomized Trial

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    AbstractArsenic trioxide (ATO) is synergistic with ascorbic acid (AA) and melphalan against myeloma both in vitro and in vivo. The aim of this randomized phase II trial was to determine the safety and efficacy of a combination of ATO, melphalan, and AA as preparative regimen in 48 patients undergoing autologous hematopoietic stem cell transplantation (ASCT) for multiple myeloma (MM). Forty-eight patients received melphalan 200 mg/m2 i.v. over 2 days and AA 1000 mg i.v. over 7 days in 3 treatment arms: no ATO (arm 1), ATO 0.15 mg/kg i.v. × 7 days (arm 2), and ATO 0.25 mg/kg i.v. × 7 days (arm 3). No dose-limiting toxicity, engraftment failure, or nonrelapse mortality (NRM) was seen in the first 100 days post-ASCT. Complete responses (CR) were seen in 12 of 48 patients (25%), with an overall response rate (ORR = CR + PR) of 85%. Median progression-free survival (PFS) was 25 months; median overall survival (OS) has not yet been reached. There was no significant difference in CR, PFS, or OS among the 3 treatment arms, and no adverse effect of ATO on melphalan pharmacokinetics. Addition of ATO + AA to high-dose melphalan is safe and well tolerated as a preparative regimen for MM

    Introductory programming: a systematic literature review

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    As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

    Ampullary cancers harbor ELF3 tumor suppressor gene mutations and exhibit frequent WNT dysregulation

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    The ampulla of Vater is a complex cellular environment from which adenocarcinomas arise to form a group of histopathologically heterogenous tumors. To evaluate the molecular features of these tumors, 98 ampullary adenocarcinomas were evaluated and compared to 44 distal bile duct and 18 duodenal adenocarcinomas. Genomic analyses revealed mutations in the WNT signaling pathway among half of the patients and in all three adenocarcinomas irrespective of their origin and histological morphology. These tumors were characterized by a high frequency of inactivating mutations of ELF3, a high rate of microsatellite instability, and common focal deletions and amplifications, suggesting common attributes in the molecular pathogenesis are at play in these tumors. The high frequency of WNT pathway activating mutation, coupled with small-molecule inhibitors of β-catenin in clinical trials, suggests future treatment decisions for these patients may be guided by genomic analysis

    Deletion of the Short Arm of Chromosome 1 (del 1p) is a Strong Predictor of Poor Outcome in Myeloma Patients Undergoing an Autotransplant

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    AbstractSeveral chromosomal abnormalities detected by conventional cytogenetic analysis have an adverse impact on the outcome in myeloma patients. A wide spectrum of abnormalities involving chromosomes 1, 13, 14, and 17 has been described. We analyzed the outcome of 83 patients with clonal cytogenetic abnormalities, who underwent high-dose therapy and autologous stem cell transplantation for multiple myeloma at our institution. Clonal abnormalities were detected at diagnosis by conventional cytogenetic analysis in 83 patients. Patients underwent a single autologous transplant between April 2000 and May 2005. Preparative regimen was high-dose melphalan alone (73), or a combination of topotecan, melphalan, and cyclophosphamide (TMC = 10). The most commonly observed chromosomal abnormalities were deletion of chromosome 13 (32%), hyperdiploidy (21%), deletion of chromosome 1p (18%), and t (11; 14) in 7% patients. Median follow-up among surviving patients was 25.5 months. Median interval from diagnosis to autotransplant was 7.7 months (range: 2.5-52). Median progression-free survival (PFS) for the entire group was 19 months and the median overall survival (OS) was 52 months. On univariate analysis, both PFS and OS were significantly shorter in patients with deletion 1p (P = .001 and <.0001, respectively). Thirty-two patients whose cytogenetic abnormalities returned to normal prior to autotransplant had longer PFS and OS than patients with persistent abnormalities (P = .02 and .08, respectively). Deletion 1p is associated with a significantly shorter remission and survival in patients undergoing high-dose therapy and a single autologous transplant for myeloma

    Human Monoclonal Antibody HCV1 Effectively Prevents and Treats HCV Infection in Chimpanzees

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    Hepatitis C virus (HCV) infection is a leading cause of liver transplantation and there is an urgent need to develop therapies to reduce rates of HCV infection of transplanted livers. Approved therapeutics for HCV are poorly tolerated and are of limited efficacy in this patient population. Human monoclonal antibody HCV1 recognizes a highly-conserved linear epitope of the HCV E2 envelope glycoprotein (amino acids 412-423) and neutralizes a broad range of HCV genotypes. In a chimpanzee model, a single dose of 250 mg/kg HCV1 delivered 30 minutes prior to infusion with genotype 1a H77 HCV provided complete protection from HCV infection, whereas a dose of 50 mg/kg HCV1 did not protect. In addition, an acutely-infected chimpanzee given 250 mg/kg HCV1 42 days following exposure to virus had a rapid reduction in viral load to below the limit of detection before rebounding 14 days later. The emergent virus displayed an E2 mutation (N415K/D) conferring resistance to HCV1 neutralization. Finally, three chronically HCV-infected chimpanzees were treated with a single dose of 40 mg/kg HCV1 and viral load was reduced to below the limit of detection for 21 days in one chimpanzee with rebounding virus displaying a resistance mutation (N417S). The other two chimpanzees had 0.5-1.0 log(10) reductions in viral load without evidence of viral resistance to HCV1. In vitro testing using HCV pseudovirus (HCVpp) demonstrated that the sera from the poorly-responding chimpanzees inhibited the ability of HCV1 to neutralize HCVpp. Measurement of antibody responses in the chronically-infected chimpanzees implicated endogenous antibody to E2 and interference with HCV1 neutralization although other factors may also be responsible. These data suggest that human monoclonal antibody HCV1 may be an effective therapeutic for the prevention of graft infection in HCV-infected patients undergoing liver transplantation
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