80 research outputs found

    Longevity of daily oral Vitamin D3 supplementation:Differences in 25OHD and 24,25(OH)2D observed 2 years after cessation of a 1-year randomized controlled trial (VICtORy RECALL)

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    Purpose To determine the longevity of vitamin D status following cessation of vitamin D3 supplementation, 2 and 3 years after a 1 year randomised double blind placebo controlled trial: (Vitamin D and Cardiovascular Risk (VICtORY)); and to investigate possible predictive factors. Method Of the 305 Caucasian non-smoking postmenopausal women randomised to ViCtORY (2009-2010), participants who had not taken vitamin D supplements since the trial ended were invited to attend follow up visits. Total 25-hydroxyvitamin D (25OHD) and 24,25-dihydroxyvitamin D (24,25OH2D) were measured by dual tandem mass spectrometry of serum samples following removal of protein and de-lipidation; the original RCT samples were re-analysed simultaneously. Vitamin D binding protein (VDBP) was measured by monoclonal immunoassay. Results In March 2012 and March 2013, 159 women (mean (SD) age 67.6 (2.1) years) re-attended, distributed between the original treatment groups: daily vitamin D3 400IU; 1000IU; and placebo. One month after the RCT ended (March 2010) the proportion of women in placebo, 400IU, and 1000IU vitamin D3 groups, respectively, with 25OHD0.001, n=46,44,54); 42%, 33%, 12% (2y, p=0.002,n=50,48,57) and 45%, 27%, 29% (3y, p=0.138, n=47,45,51,). VDBP was a predictor of circulating 25OHD longevity (beta for VDBP in Β΅g/ml:0.736; 95% CI 0.216-1.255,p=0.006) but not 24,25OH2D

    Vitamin D Induction of the Human Antimicrobial Peptide Cathelicidin in the Urinary Bladder

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    The urinary tract is frequently being exposed to potential pathogens and rapid defence mechanisms are therefore needed. Cathelicidin, a human antimicrobial peptide is expressed and secreted by bladder epithelial cells and protects the urinary tract from infection. Here we show that vitamin D can induce cathelicidin in the urinary bladder. We analyzed bladder tissue from postmenopausal women for expression of cathelicidin, before and after a three-month period of supplementation with 25-hydroxyvitamin D3 (25D3). Cell culture experiments were performed to elucidate the mechanisms for cathelicidin induction. We observed that, vitamin D per se did not up-regulate cathelicidin in serum or in bladder tissue of the women in this study. However, when the bladder biopsies were infected with uropathogenic E. coli (UPEC), a significant increase in cathelicidin expression was observed after 25D3 supplementation. This observation was confirmed in human bladder cell lines, even though here, cathelicidin induction occurred irrespectively of infection. Vitamin D treated bladder cells exerted an increased antibacterial effect against UPEC and colocalization to cathelicidin indicated the relevance of this peptide. In the light of the rapidly growing problem of resistance to common urinary tract antibiotics, we suggest that vitamin D may be a potential complement in the prevention of UTI

    Vitamin D levels and susceptibility to asthma, elevated immunoglobulin E levels, and atopic dermatitis: A Mendelian randomization study.

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    BACKGROUND: Low circulating vitamin D levels have been associated with risk of asthma, atopic dermatitis, and elevated total immunoglobulin E (IgE). These epidemiological associations, if true, would have public health importance, since vitamin D insufficiency is common and correctable. METHODS AND FINDINGS: We aimed to test whether genetically lowered vitamin D levels were associated with risk of asthma, atopic dermatitis, or elevated serum IgE levels, using Mendelian randomization (MR) methodology to control bias owing to confounding and reverse causation. The study employed data from the UK Biobank resource and from the SUNLIGHT, GABRIEL and EAGLE eczema consortia. Using four single-nucleotide polymorphisms (SNPs) strongly associated with 25-hydroxyvitamin D (25OHD) levels in 33,996 individuals, we conducted MR studies to estimate the effect of lowered 25OHD on the risk of asthma (n = 146,761), childhood onset asthma (n = 15,008), atopic dermatitis (n = 40,835), and elevated IgE level (n = 12,853) and tested MR assumptions in sensitivity analyses. None of the four 25OHD-lowering alleles were associated with asthma, atopic dermatitis, or elevated IgE levels (p β‰₯ 0.2). The MR odds ratio per standard deviation decrease in log-transformed 25OHD was 1.03 (95% confidence interval [CI] 0.90-1.19, p = 0.63) for asthma, 0.95 (95% CI 0.69-1.31, p = 0.76) for childhood-onset asthma, and 1.12 (95% CI 0.92-1.37, p = 0.27) for atopic dermatitis, and the effect size on log-transformed IgE levels was -0.40 (95% CI -1.65 to 0.85, p = 0.54). These results persisted in sensitivity analyses assessing population stratification and pleiotropy and vitamin D synthesis and metabolism pathways. The main limitations of this study are that the findings do not exclude an association between the studied outcomes and 1,25-dihydoxyvitamin D, the active form of vitamin D, the study was underpowered to detect effects smaller than an OR of 1.33 for childhood asthma, and the analyses were restricted to white populations of European ancestry. This research has been conducted using the UK Biobank Resource and data from the SUNLIGHT, GABRIEL and EAGLE Eczema consortia. CONCLUSIONS: In this study, we found no evidence that genetically determined reduction in 25OHD levels conferred an increased risk of asthma, atopic dermatitis, or elevated total serum IgE, suggesting that efforts to increase vitamin D are unlikely to reduce risks of atopic disease

    Regulation of Mycobacterium-Specific Mononuclear Cell Responses by 25-Hydroxyvitamin D3

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    The active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), has been shown to be an important regulator of innate and adaptive immune function. In addition, synthesis of 1,25(OH)2D3 from 25-hydroxyvitamin D3 (25(OH)D3) by the enzyme 1Ξ±-hydroxylase in monocytes upon activation by TLR signaling has been found to regulate innate immune responses of monocytes in an intracrine fashion. In this study we wanted to determine what cells expressed 1Ξ±-hydroxylase in stimulated peripheral blood mononuclear cell (PBMC) cultures and if conversion of 25(OH)D3 to 1,25(OH)2D3 in PBMC cultures regulated antigen-specific immune responses. Initially, we found that stimulation of PBMCs from animals vaccinated with Mycobacterium bovis (M. bovis) BCG with purified protein derivative of M. bovis (M. bovis PPD) induced 1Ξ±-hydroxylase gene expression and that treatment with a physiological concentration of 25(OH)D3 down-regulated IFN-Ξ³ and IL-17F gene expression. Next, we stimulated PBMCs from M. bovis BCG-vaccinated and non-vaccinated cattle with M. bovis PPD and sorted them by FACS according to surface markers for monocytes/macrophages (CD14), B cells (IgM), and T cells (CD3). Sorting the PBMCs revealed that 1Ξ±-hydroxylase expression was induced in the monocytes and B cells, but not in the T cells. Furthermore, treatment of stimulated PBMCs with 25(OH)D3 down-regulated antigen-specific IFN-Ξ³ and IL-17F responses in the T cells, even though 1Ξ±-hydroxylase expression was not induced in the T cells. Based on evidence of no T cell 1Ξ±-hydroxylase we hypothesize that activated monocytes and B cells synthesize 1,25(OH)2D3 and that 1,25(OH)2D3 down-regulates antigen-specific expression of IFN-Ξ³ and IL-17F in T cells in a paracrine fashion

    Processes of local alcohol policy-making in England: Does the theory of policy transfer provide useful insights into public health decision-making?

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    BACKGROUND AND AIMS: Recent years have seen a rise in new and innovative policies to reduce alcohol consumption and related harm in England, which can be implemented by local, as opposed to national, policy-makers. The aim of this paper is to explore the processes that underpin the adoption of these alcohol policies within local authorities. In particular, it aims to assess whether the concept of policy transfer (i.e. a process through which knowledge about policies in one place is used in the development of policies in another time or place) provides a useful model for understanding local alcohol policy-making. METHODS: Qualitative data generated through in-depth interviews and focus groups from five case study sites across England were used to explore stakeholder experiences of alcohol policy transfer between local authorities. The purposive sample of policy actors included representatives from the police, trading standards, public health, licensing, and commissioning. Thematic analysis was used inductively to identify key features in the data. RESULTS: Themes from the policy transfer literature identified in the data were: policy copying, emulating, hybridization, and inspiration. Participants described a multitude of ways in which learning was shared between places, ranging from formal academic evaluation to opportunistic conversations in informal settings. Participants also described facilitators and constraints to policy transfer, such as the historical policy context and the local cultural, economic, and bureaucratic context, which influenced whether or not a policy that was perceived to work in one place might be transferred successfully to another context. CONCLUSIONS: Theories of policy transfer provide a promising framework for characterising processes of local alcohol policy-making in England, extending beyond debates regarding evidence-informed policy to account for a much wider range of considerations. Applying a policy transfer lens enables us to move beyond simple (but still important) questions of what is supported by 'robust' research evidence by paying greater attention to how policy making is carried out in practice and the multiple methods by which policies diffuse across jurisdictions

    The effects of vitamin D-2 or D-3 supplementation on glycaemic control and related metabolic parameters in people at risk of type 2 diabetes: protocol of a randomised double-blind placebo-controlled trial

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    This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.London – Block grant from Tower Hamlets Primary Care NHS Trust and East London CLRN. Cambridge – From the operational budget of Medical Research Council Epidemiology Unit (MC_UP_A100_1003)

    The cellular geography of Aurora kinases

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    Aurora is the name given to a family of highly conserved protein kinases with essential roles in many aspects of cell division. Yeasts have a single Aurora kinase, whereas mammals have three: Aurora A, B and C. During mitosis, Aurora kinases regulate the structure and function of the cytoskeleton and chromosomes and the interactions between these two at the kinetochore. They also regulate signalling by the spindle-assembly checkpoint pathway and cytokinesis. Perturbation of Aurora kinase expression or function might lead to cancer
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