245 research outputs found

    Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition

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    Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 °C. The films were annealed at 600 °C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system

    Chronic myeloid leukemia stem cells are not dependent on Bcr-Abl kinase activity for their survival

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    Recent evidence suggests CML stem cells are insensitive to kinase inhibitors and responsible for minimal residual disease in treated patients. We investigated whether CML stem cells, in a transgenic mouse model of CML-like disease or derived from patients, are dependent on Bcr-Abl. In the transgenic model, following re-transplantation, donor-derived CML stem cells in which Bcr-Abl expression had been induced and subsequently shut off, were able to persist in vivo and re-initiate leukemia in secondary recipients upon Bcr-Abl re-expression. Bcr-Abl knockdown in human CD34+ CML cells cultured for 12 days in physiological growth factors achieved partial inhibition of Bcr-Abl and downstream targets p-CrkL and p-STAT5, inhibition of proliferation and colony forming cells, but no reduction of input cells. The addition of dasatinib further inhibited p-CrkL and p-STAT5, yet only reduced input cells by 50%. Complete growth factor withdrawal plus dasatinib further reduced input cells to 10%, however the surviving fraction was enriched for primitive leukemic cells capable of growth in long-term culture initiating cell assay and expansion upon removal of dasatinib and addition of growth factors. Together these data suggest that CML stem cell survival is Bcr-Abl kinase independent and suggest curative approaches in CML must focus on kinase-independent mechanisms of resistance

    Formative Research in School and Community-Based Health Programs and Studies: “State of the Art” and the TAAG Approach

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    Formative research uses qualitative and quantitative methods to provide information for researchers to plan intervention programs. Gaps in the formative research literature include how to define goals, implementation plans, and research questions; select methods; analyze data; and develop interventions. The National Heart, Lung, and Blood Institute funded the Trial of Activity for Adolescent Girls (TAAG), a randomized, multicenter field trial, to reduce the decline in physical activity in adolescent girls. The goals of the TAAG formative research are to (a) describe study communities and schools, (b) help design the trial’s interventions, (c) develop effective recruitment and retention strategies, and (d) design evaluation instruments. To meet these goals, a variety of methods, including telephone interviews, surveys and checklists, semistructured interviews, and focus group discussions, are employed. The purpose, method of development, and analyses are explained for each method

    The kSORT assay to detect renal transplant patients at high risk for acute rejection: results of the multicenter AART study

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    Abstract Background: Development of noninvasive molecular assays to improve disease diagnosis and patient monitoring is a critical need. In renal transplantation, acute rejection (AR) increases the risk for chronic graft injury and failure. Noninvasive diagnostic assays to improve current late and nonspecific diagnosis of rejection are needed. We sought to develop a test using a simple blood gene expression assay to detect patients at high risk for AR. Methods and Findings: We developed a novel correlation-based algorithm by step-wise analysis of gene expression data in 558 blood samples from 436 renal transplant patients collected across eight transplant centers in the US, Mexico, and Spain between 5 February 2005 and 15 December 2012 in the Assessment of Acute Rejection in Renal Transplantation (AART)study. Gene expression was assessed by quantitative real-time PCR (QPCR) in one center. A 17-gene set the Kidney Solid Organ Response Test (kSORT) was selected in 143 samples for AR classification using discriminant analysis (area under the receiver operating characteristic curve [AUC] = 0.94; 95% CI 0.91-0.98), validated in 124 independent samples (AUC = 0.95; 95% CI 0.88-1.0) and evaluated for AR prediction in 191 serial samples, where it predicted AR up to 3 mo prior to detection by the current gold standard (biopsy). A novel reference-based algorithm (using 13 12-gene models) was developed in 100 independent samples to provide a numerical AR risk score, to classify patients as high risk versus low risk for AR. kSORT was able to detect AR in blood independent of age, time post-transplantation, and sample source without additional data normalization; AUC = 0.93 (95% CI 0.86-0.99). Further validation of kSORT is planned in prospective clinical observational and interventional trials. Conclusions: The kSORT blood QPCR assay is a noninvasive tool to detect high risk of AR of renal transplants

    Autocrine TNF-α production supports CML stem and progenitor cell survival and enhances their proliferation.

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    Chronic myeloid leukemia (CML) stem cells are not dependent on BCR-ABL kinase for their survival, suggesting that kinase-independent mechanisms must contribute to their persistence. We observed that CML stem/progenitor cells (SPCs) produce tumor necrosis factor-α (TNF-α) in a kinase-independent fashion and at higher levels relative to their normal counterparts. We therefore investigated the role of TNF-α and found that it supports survival of CML SPCs by promoting nuclear factor κB/p65 pathway activity and expression of the interleukin 3 and granulocyte/macrophage-colony stimulating factor common β-chain receptor. Furthermore, we demonstrate that in CML SPCs, inhibition of autocrine TNF-α signaling via a small-molecule TNF-α inhibitor induces apoptosis. Moreover TNF-α inhibition combined with nilotinib induces significantly more apoptosis relative to either treatment alone and a reduction in the absolute number of primitive quiescent CML stem cells. These results highlight a novel survival mechanism of CML SPCs and suggest a new putative therapeutic target for their eradication.This study was supported by the Glasgow Experimental Cancer Medicine Centre , which is funded by Cancer Research UK and by the Chief Scientist’s Office, Scotland. Cell sorting facilities were funded by the Kay Kendall Leukaemia Fund (KKL501) and the Howat Foundation. Funding was provided by Medical Research Council UK clinical research training fellowship grant G1000288 (P.G.), Cancer Research UK Programme grant C11074/A11008 and the Elimination of Leukaemia Fund (ELF/6/ 29/1) (F.P.), National Institutes of Health, National Cancer Institute research grant R01 CA095684 (R.B.), by the Friends of Paul O’Gorman Leukaemia Research Centre (H.G.J.), and Cancer Research UK Programme grant C11074/A11008 (T.L.H.)

    Rare copy number variants: a point of rarity in genetic risk for bipolar disorder and schizophrenia

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    Context: Recent studies suggest that copy number variation in the human genome is extensive and may play an important role in susceptibility to disease, including neuropsychiatric disorders such as schizophrenia and autism. The possible involvement of copy number variants (CNVs) in bipolar disorder has received little attention to date. Objectives: To determine whether large (>100 000 base pairs) and rare (found in <1% of the population) CNVs are associated with susceptibility to bipolar disorder and to compare with findings in schizophrenia. Design: A genome-wide survey of large, rare CNVs in a case-control sample using a high-density microarray. Setting: The Wellcome Trust Case Control Consortium. Participants: There were 1697 cases of bipolar disorder and 2806 nonpsychiatric controls. All participants were white UK residents. Main Outcome Measures: Overall load of CNVs and presence of rare CNVs. Results: The burden of CNVs in bipolar disorder was not increased compared with controls and was significantly less than in schizophrenia cases. The CNVs previously implicated in the etiology of schizophrenia were not more common in cases with bipolar disorder. Conclusions: Schizophrenia and bipolar disorder differ with respect to CNV burden in general and association with specific CNVs in particular. Our data are consistent with the possibility that possession of large, rare deletions may modify the phenotype in those at risk of psychosis: those possessing such events are more likely to be diagnosed as having schizophrenia, and those without them are more likely to be diagnosed as having bipolar disorder

    Domestication of Campylobacter jejuni NCTC 11168

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    Reference and type strains of well-known bacteria have been a cornerstone of microbiology research for decades. The sharing of well-characterized isolates among laboratories has run in parallel with research efforts and enhanced the reproducibility of experiments, leading to a wealth of knowledge about trait variation in different species and the underlying genetics. Campylobacter jejuni strain NCTC 11168, deposited at the National Collection of Type Cultures in 1977, has been adopted widely as a reference strain by researchers worldwide and was the first Campylobacter for which the complete genome was published (in 2000). In this study, we collected 23 C . jejuni NCTC 11168 reference isolates from laboratories across the UK and compared variation in simple laboratory phenotypes with genetic variation in sequenced genomes. Putatively identical isolates, identified previously to have aberrant phenotypes, varied by up to 281 SNPs (in 15 genes) compared to the most recent reference strain. Isolates also display considerable phenotype variation in motility, morphology, growth at 37 °C, invasion of chicken and human cell lines, and susceptibility to ampicillin. This study provides evidence of ongoing evolutionary change among C. jejuni isolates as they are cultured in different laboratories and highlights the need for careful consideration of genetic variation within laboratory reference strains. This article contains data hosted by Microreact

    Research cardiac magnetic resonance imaging in end stage renal disease - incidence, significance and implications of unexpected incidental findings

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    Objectives: Left ventricular mass (LVM) at cardiac magnetic resonance imaging (CMR) is a frequent end point in clinical trials in nephrology. Trial participants with end stage renal disease (ESRD) may have a greater frequency of incidental findings (IF). We retrospectively investigated prevalence of IF in previous research CMR and reviewed their subsequent impact on participants. Methods: Between 2002 and 2006, 161 ESRD patients underwent CMR in a transplant assessment study. Images were used to assess LV mass and function. In the current study a radiologist reviewed the scans for IF. Review of patient records determined the subsequent clinical significance of IF. Results: There were 150 IF in 95 study participants. Eighty-four (56 %) were new diagnoses. One hundred and two were non-cardiac. Fifteen were suspicious of malignancy. There was a clinically significant IF for 14.9 % of the participants. In six cases earlier identification of an IF may have improved quality of life or survival. Conclusions: Without radiology support clinically important IF may be missed on CMR. Patients undergoing CMR in trials should be counselled about the frequency and implications of IF. Patients with ESRD have a higher prevalence of IF than reported in other populations. Nephrology studies require mechanisms for radiologist reporting and strategies for dealing with IF

    Defining myocardial tissue abnormalities in end-stage renal failure with cardiac magnetic resonance imaging using native T1 mapping

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    Noninvasive quantification of myocardial fibrosis in end-stage renal disease is challenging. Gadolinium contrast agents previously used for cardiac magnetic resonance imaging (MRI) are contraindicated because of an association with nephrogenic systemic fibrosis. In other populations, increased myocardial native T1 times on cardiac MRI have been shown to be a surrogate marker of myocardial fibrosis. We applied this method to 33 incident hemodialysis patients and 28 age- and sex-matched healthy volunteers who underwent MRI at 3.0T. Native T1 relaxation times and feature tracking–derived global longitudinal strain as potential markers of fibrosis were compared and associated with cardiac biomarkers. Left ventricular mass indices were higher in the hemodialysis than the control group. Global, Septal and midseptal T1 times were all significantly higher in the hemodialysis group (global T1 hemodialysis 1171 ± 27 ms vs. 1154 ± 32 ms; septal T1 hemodialysis 1184 ± 29 ms vs. 1163 ± 30 ms; and midseptal T1 hemodialysis 1184 ± 34 ms vs. 1161 ± 29 ms). In the hemodialysis group, T1 times correlated with left ventricular mass indices. Septal T1 times correlated with troponin and electrocardiogram-corrected QT interval. The peak global longitudinal strain was significantly reduced in the hemodialysis group (hemodialysis -17.7±5.3% vs. -21.8±6.2%). For hemodialysis patients, the peak global longitudinal strain significantly correlated with left ventricular mass indices (R = 0.426), and a trend was seen for correlation with galectin-3, a biomarker of cardiac fibrosis. Thus, cardiac tissue properties of hemodialysis patients consistent with myocardial fibrosis can be determined noninvasively and associated with multiple structural and functional abnormalities
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