1,081 research outputs found

    Systematic review and meta-analysis of the growth and rupture rates of small abdominal aortic aneurysms: implications for surveillance intervals and their cost-effectiveness.

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    BACKGROUND: Small abdominal aortic aneurysms (AAAs; 3.0-5.4 cm in diameter) are usually asymptomatic and managed by regular ultrasound surveillance until they grow to a diameter threshold (commonly 5.5 cm) at which surgical intervention is considered. The choice of appropriate surveillance intervals is governed by the growth and rupture rates of small AAAs, as well as their relative cost-effectiveness. OBJECTIVES: The aim of this series of studies was to inform the evidence base for small AAA surveillance strategies. This was achieved by literature review, collation and analysis of individual patient data, a focus group and health economic modelling. DATA SOURCES: We undertook systematic literature reviews of growth rates and rupture rates of small AAAs. The databases MEDLINE, EMBASE on OvidSP, Cochrane Central Register of Controlled Trials 2009 Issue 4, ClinicalTrials.gov, and controlled-trials.com were searched from inception up until the end of 2009. We also obtained individual data on 15,475 patients from 18 surveillance studies. REVIEW METHODS: Systematic reviews of publications identified 15 studies providing small AAA growth rates, and 14 studies with small AAA rupture rates, up to December 2009 (later updated to September 2012). We developed statistical methods to analyse individual surveillance data, including the effects of patient characteristics, to inform the choice of surveillance intervals and provide inputs for health economic modelling. We updated an existing health economic model of AAA screening to address the cost-effectiveness of different surveillance intervals. RESULTS: In the literature reviews, the mean growth rate was 2.3 mm/year and the reported rupture rates varied between 0 and 1.6 ruptures per 100 person-years. Growth rates increased markedly with aneurysm diameter, but insufficient detail was available to guide surveillance intervals. Based on individual surveillance data, for each 0.5-cm increase in AAA diameter, growth rates increased by about 0.5 mm/year and rupture rates doubled. To control the risk of exceeding 5.5 cm to below 10% in men, on average a 7-year surveillance interval is sufficient for a 3.0-cm aneurysm, whereas an 8-month interval is necessary for a 5.0-cm aneurysm. To control the risk of rupture to below 1%, the corresponding estimated surveillance intervals are 9 years and 17 months. Average growth rates were higher in smokers (by 0.35 mm/year) and lower in patients with diabetes (by 0.51 mm/year). Rupture rates were almost fourfold higher in women than men, doubled in current smokers and increased with higher blood pressure. Increasing the surveillance interval from 1 to 2 years for the smallest aneurysms (3.0-4.4 cm) decreased costs and led to a positive net benefit. For the larger aneurysms (4.5-5.4 cm), increasing surveillance intervals from 3 to 6 months led to equivalent cost-effectiveness. LIMITATIONS: There were no clear reasons why the growth rates varied substantially between studies. Uniform diagnostic criteria for rupture were not available. The long-term cost-effectiveness results may be susceptible to the modelling assumptions made. CONCLUSIONS: Surveillance intervals of several years are clinically acceptable for men with AAAs in the range 3.0-4.0 cm. Intervals of around 1 year are suitable for 4.0-4.9-cm AAAs, whereas intervals of 6 months would be acceptable for 5.0-5.4-cm AAAs. These intervals are longer than those currently employed in the UK AAA screening programmes. Lengthening surveillance intervals for the smallest aneurysms was also shown to be cost-effective. Future work should focus on optimising surveillance intervals for women, studying whether or not the threshold for surgery should depend on patient characteristics, evaluating the usefulness of surveillance for those with aortic diameters of 2.5-2.9 cm, and developing interventions that may reduce the growth or rupture rates of small AAAs. FUNDING: The National Institute for Health Research Health Technology Assessment programme

    Genomics and successful aging: grounds for renewed optimism?

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    This is a pre-copyedited, author-produced PDF of an article accepted for publication in the Journals of Gerentology following peer review. The version of record is available online at: doi: 10.1093/gerona/gls091.Successful aging depends in part on delaying age-related disease onsets until later in life. Conditions including coronary artery disease, Alzheimer's disease, prostate cancer, and type 2 diabetes are moderately heritable. Genome-wide association studies have identified many risk associated single-nucleotide polymorphisms for these conditions, but much heritability remains unaccounted for. Nevertheless, a great deal is being learned.Dunhill Medical TrustU.S. National Institutes of Healt

    Linking the oceans to public health: current efforts and future directions

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    This is the final version of the article. Available from BioMed Central via the DOI in this recordWe review the major linkages between the oceans and public health, focusing on exposures and potential health effects due to anthropogenic and natural factors including: harmful algal blooms, microbes, and chemical pollutants in the oceans; consumption of seafood; and flooding events. We summarize briefly the current state of knowledge about public health effects and their economic consequences; and we discuss priorities for future research.We find that:* There are numerous connections between the oceans, human activities, and human health that result in both positive and negative exposures and health effects (risks and benefits); and the study of these connections comprises a new interdisciplinary area, "oceans and human health."* The state of present knowledge about the linkages between oceans and public health varies. Some risks, such as the acute health effects caused by toxins associated with shellfish poisoning and red tide, are relatively well understood. Other risks, such as those posed by chronic exposure to many anthropogenic chemicals, pathogens, and naturally occurring toxins in coastal waters, are less well quantified. Even where there is a good understanding of the mechanism for health effects, good epidemiological data are often lacking. Solid data on economic and social consequences of these linkages are also lacking in most cases.* The design of management measures to address these risks must take into account the complexities of human response to warnings and other guidance, and the economic tradeoffs among different risks and benefits. Future research in oceans and human health to address public health risks associated with marine pathogens and toxins, and with marine dimensions of global change, should include epidemiological, behavioral, and economic components to ensure that resulting management measures incorporate effective economic and risk/benefit tradeoffs.Funding was provided in part by the NSF-NIEHS Oceans Centers at Woods Hole, University of Hawaii, University of Miami, and University of Washington, and the NOAA Oceans and Human Health Initiative Centers of Excellent in Charleston, Seattle and Milwaukee, the National Center for Environmental Health (NCEH) of the Centers for Disease Control and Prevention (CDC), and the WHOI Marine Policy Center. Grant numbers are: NIEHS P50 ES012742 and NSF OCE-043072 (HLKP, RJG, PH); NSF OCE-0432368 and NIEHS P50 ES12736 (LEF); NIEHS P50 ES012762 and NSF OCE-0434087 (EMF, AT, LRY); NSF OCE04-32479 and NIEHS P50 ES012740 (BAW

    North and North East Lincolnshire Gypsy and Traveller accommodation needs assessment : Executive summary

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    This report provides an executive summary of Gypsy and Traveller accommodation needs assessment in North and North East Lincolnshire. This research was commissioned by North Lincolnshire Council and North East Lincolnshire District Council in August 2007. The study was led by a team of researchers from the Salford Housing & Urban Studies Unit (SHUSU) at the University of Salford with support from researchers at the Centre for Regional, Economic and Social Research (CRESR) at Sheffield Hallam University. The study was managed by a Steering Group composed of officers representing the commissioning authorities. This report also builds on a previous exploratory study commissioned by the two local authorities in 2005

    North and North East Lincolnshire Gypsy and Traveller accommodation needs assessment : Final report

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    This report presents the findings of an assessment of the accommodation needs of Gypsies and Travellers across North and North East Lincolnshire. The research and report were commissioned by the two unitary authorities (North Lincolnshire Council and North East Lincolnshire District Council) in August 2007. The study was led by a team of researchers from the Salford Housing & Urban Studies Unit (SHUSU) at the University of Salford with support from researchers at the Centre for Regional, Economic and Social Research (CRESR) at Sheffield Hallam University. The study was greatly aided by research support and expertise from members of the Gypsy and Traveller communities. The study was managed by a Steering Group composed of officers representing the commissioning authorities. This report also builds on a previous exploratory study commissioned by the two local authorities in 2005

    Reduction of T-Helper Cell Responses to Recall Antigen Medicated by Codelivery with Peptidoglycan via the Intestinal Nanomineral-Antigen Pathway

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    Naturally occurring intestinal nanomineral particles constituently form in the mammalian gut and trap luminal protein and microbial components. These cargo loaded nanominerals are actively scavenged by M cells of intestinal immune follicles, such as Peyer’s patches and are passed to antigen-presenting cells. Using peripheral blood mononuclear cell populations as an in vitro model of nanomineral uptake and antigen presentation, we show that monocytes avidly phagocytose nanomineral particles bearing antigen and peptidoglycan (PGN), and that the presence of PGN within particles downregulates their cell surface MHC class II and upregulates programmed death receptor ligand 1. Nanomineral delivery of antigen suppresses antigen-specific CD4+ T cell responses, an effect that is enhanced in the presence of PGN. Blocking the interleukin-10 receptor restores CD4+ T cell responses to antigen codelivered with PGN in nanomineral form. Using human intestinal specimens, we have shown that the in vivo nanomineral pathway operates in an interleukin-10 rich environment. Consequently, the delivery of a dual antigen–PGN cargo by endogenous nanomineral in vivo is likely to be important in the establishment of intestinal tolerance, while their synthetic mimetics present a potential delivery system for therapeutic applications targeting the modulation of Peyer’s patch T cell responses

    An Approximate Dynamic Programming Approach to Urban Freight Distribution with Batch Arrivals

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    We study an extension of the delivery dispatching problem (DDP) with time windows, applied on LTL orders arriving at an urban consolidation center. Order properties (e.g., destination, size, dispatch window) may be highly varying, and directly distributing an incoming order batch may yield high costs. Instead, the hub operator may wait to consolidate with future arrivals. A consolidation policy is required to decide which orders to ship and which orders to hold. We model the dispatching problem as a Markov decision problem. Dynamic Programming (DP) is applied to solve toy-sized instances to optimality. For larger instances, we propose an Approximate Dynamic Programming (ADP) approach. Through numerical experiments, we show that ADP closely approximates the optimal values for small instances, and outperforms two myopic benchmark policies for larger instances. We contribute to literature by (i) formulating a DDP with dispatch windows and (ii) proposing an approach to solve this DDP

    Nef does not contribute to replication differences between R5 pre-AIDS and AIDS HIV-1 clones from patient ACH142

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    AIDS-associated, CCR5-tropic (R5) HIV-1 clones, isolated from a patient that never developed CXCR4-tropic HIV-1, replicate to a greater extent and cause greater cytopathic effects than R5 HIV-1 clones isolated before the onset of AIDS. Previously, we showed that HIV-1 Env substantially contributed to the enhanced replication of an AIDS clone. In order to determine if Nef makes a similar contribution, we cloned and phenotypically analyzed nef genes from a series of patient ACH142 derived R5 HIV-1 clones. The AIDS-associated Nef contains a series of residues found in Nef proteins from progressors [1]. In contrast to other reports [1-3], this AIDS-associated Nef downmodulated MHC-I to a greater extent and CD4 less than pre-AIDS Nef proteins. Additionally, all Nef proteins enhanced infectivity similarly in a single round of replication. Combined with our previous study, these data show that evolution of the HIV-1 env gene, but not the nef gene, within patient ACH142 significantly contributed to the enhanced replication and cytopathic effects of the AIDS-associated R5 HIV-1 clone

    Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival

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    Extent: 14 p.The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K), promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML) cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3) and granulocyte macrophage colony stimulating factor (GM-CSF) receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting such pathways in cancer.Daniel Thomas, Jason A. Powell, Benjamin D. Green, Emma F. Barry, Yuefang Ma, Joanna Woodcock, Stephen Fitter, Andrew C.W. Zannettino, Stuart M. Pitson, Timothy P. Hughes, Angel F. Lopez, Peter R. Shepherd, Andrew H. Wei, Paul G. Ekert and Mark A. Guthridg
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