216 research outputs found

    MFGE8 does not influence chorio-retinal homeostasis or choroidal neovascularization in vivo

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    Purpose: Milk fat globule-epidermal growth factor-factor VIII (MFGE8) is necessary for diurnal outer segment phagocytosis and promotes VEGF-dependent neovascularization. The prevalence of two single nucleotide polymorphisms (SNP) in MFGE8 was studied in two exsudative or “wet” Age-related Macular Degeneration (AMD) groups and two corresponding control groups. We studied the effect of MFGE8 deficiency on retinal homeostasis with age and on choroidal neovascularization (CNV) in mice. Methods: The distribution of the SNP (rs4945 and rs1878326) of MFGE8 was analyzed in two groups of patients with “wet” AMD and their age-matched controls from Germany and France. MFGE8-expressing cells were identified in Mfge8+/− mice expressing ß-galactosidase. Aged Mfge8+/− and Mfge8−/− mice were studied by funduscopy, histology, electron microscopy, scanning electron microscopy of vascular corrosion casts of the choroid, and after laser-induced CNV. Results: rs1878326 was associated with AMD in the French and German group. The Mfge8 promoter is highly active in photoreceptors but not in retinal pigment epithelium cells. Mfge8−/− mice did not differ from controls in terms of fundus appearance, photoreceptor cell layers, choroidal architecture or laser-induced CNV. In contrast, the Bruch's membrane (BM) was slightly but significantly thicker in Mfge8−/− mice as compared to controls. Conclusions: Despite a reproducible minor increase of rs1878326 in AMD patients and a very modest increase in BM in Mfge8−/− mice, our data suggests that MFGE8 dysfunction does not play a critical role in the pathogenesis of AMD

    International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol

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    Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature. There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed

    Axion-like-particle search with high-intensity lasers

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    We study ALP-photon-conversion within strong inhomogeneous electromagnetic fields as provided by contemporary high-intensity laser systems. We observe that probe photons traversing the focal spot of a superposition of Gaussian beams of a single high-intensity laser at fundamental and frequency-doubled mode can experience a frequency shift due to their intermittent propagation as axion-like-particles. This process is strongly peaked for resonant masses on the order of the involved laser frequencies. Purely laser-based experiments in optical setups are sensitive to ALPs in the eV\mathrm{eV} mass range and can thus complement ALP searches at dipole magnets.Comment: 25 pages, 2 figure

    The Inflammatory Response to Double Stranded DNA in Endothelial Cells Is Mediated by NFκB and TNFα

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    Endothelial cells represent an important barrier between the intravascular compartment and extravascular tissues, and therefore serve as key sensors, communicators, and amplifiers of danger signals in innate immunity and inflammation. Double stranded DNA (dsDNA) released from damaged host cells during injury or introduced by pathogens during infection, has emerged as a potent danger signal. While the dsDNA-mediated immune response has been extensively studied in immune cells, little is known about the direct and indirect effects of dsDNA on the vascular endothelium. In this study we show that direct dsDNA stimulation of endothelial cells induces a potent proinflammatory response as demonstrated by increased expression of ICAM1, E-selectin and VCAM1, and enhanced leukocyte adhesion. This response was dependent on the stress kinases JNK and p38 MAPK, required the activation of proinflammatory transcription factors NFκB and IRF3, and triggered the robust secretion of TNFα for sustained secondary activation of the endothelium. DNA-induced TNFα secretion proved to be essential in vivo, as mice deficient in the TNF receptor were unable to mount an acute inflammatory response to dsDNA. Our findings suggest that the endothelium plays an active role in mediating dsDNA-induced inflammatory responses, and implicate its importance in establishing an acute inflammatory response to sterile injury or systemic infection, where host or pathogen derived dsDNA may serve as a danger signal.United States. Dept. of Defense (CDMRP Predoctoral Training Award)National Institutes of Health (U.S.) (NIH BioMEMS Resource Center Grant P41 EB-002503)National Institutes of Health (U.S.) (NIH Grant RO1AI063795)Shriners Hospital for Childre

    Evidence of gene-environment interaction for two genes on chromosome 4 and environmental tobacco smoke in controlling the risk of nonsyndromic cleft palate

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    Nonsyndromic cleft palate (CP) is one of the most common human birth defects and both genetic and environmental risk factors contribute to its etiology. We conducted a genome-wide association study (GWAS) using 550 CP case-parent trios ascertained in an international consortium. Stratified analysis among trios with different ancestries was performed to test for GxE interactions with common maternal exposures using conditional logistic regression models. While no single nucleotide polymorphism (SNP) achieved genome-wide significance when considered alone, markers in SLC2A9 and the neighboring WDR1 on chromosome 4p16.1 gave suggestive evidence of gene-environment interaction with environmental tobacco smoke (ETS) among 259 Asian trios when the models included a term for GxE interaction. Multiple SNPs in these two genes were associated with increased risk of nonsyndromic CP if the mother was exposed to ETS during the peri-conceptual period (3 months prior to conception through the first trimester). When maternal ETS was considered, fifteen of 135 SNPs mapping to SLC2A9 and 9 of 59 SNPs in WDR1 gave P values approaching genome-wide significance (10-6<P<10-4) in a test for GxETS interaction. SNPs rs3733585 and rs12508991 in SLC2A9 yielded P = 2.26×10-7 in a test for GxETS interaction. SNPs rs6820756 and rs7699512 in WDR1 also yielded P = 1.79×10-7 and P = 1.98×10-7 in a 1 df test for GxE interaction. Although further replication studies are critical to confirming these findings, these results illustrate how genetic associations for nonsyndromic CP can be missed if potential GxE interaction is not taken into account, and this study suggest SLC2A9 and WDR1 should be considered as candidate genes for CP. © 2014 Wu et al

    Improving the use of research evidence in guideline development: 5. Group processes

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    BACKGROUND: The World Health Organization (WHO), like many other organisations around the world, has recognised the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the fifth of a series of 16 reviews that have been prepared as background for advice from the WHO Advisory Committee on Health Research to WHO on how to achieve this. OBJECTIVE: In this review we address approaches to facilitate sound processes within groups that develop recommendations for health care. METHODS: We searched PubMed and three databases of methodological studies for existing systematic reviews and relevant methodological research. We did not conduct systematic reviews ourselves. Our conclusions are based on the available evidence, consideration of what WHO and other organisations are doing and logical arguments. KEY QUESTION AND ANSWER: What should WHO do to ensure appropriate group processes? Various strategies can be adopted to ensure that the group processes in play when panels are developing recommendations are inclusive, so that all voices can be heard and all arguments given fair weight, including • the use of formal consensus development methods, such at the Nominal Group Technique or the Delphi method • the selection of a group leader who is qualified and responsible for facilitating an appropriate group process

    Improving the use of research evidence in guideline development: 15. Disseminating and implementing guidelines

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    BACKGROUND: The World Health Organization (WHO), like many other organisations around the world, has recognised the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the 15(th )of a series of 16 reviews that have been prepared as background for advice from the WHO Advisory Committee on Health Research to WHO on how to achieve this. OBJECTIVES: In this review we address strategies for the implementation of recommendations in health care. METHODS: We examined overviews of systematic reviews of interventions to improve health care delivery and health care systems prepared by the Cochrane Effective Practice and Organisation of Care (EPOC) group. We also conducted searches using PubMed and three databases of methodological studies for existing systematic reviews and relevant methodological research. We did not conduct systematic reviews ourselves. Our conclusions are based on the available evidence, consideration of what WHO and other organisations are doing and logical arguments. KEY QUESTIONS AND ANSWERS: What should WHO do to disseminate and facilitate the uptake of recommendations? • WHO should choose strategies to implement their guidelines from among those which have been evaluated positively in the published literature on implementation research • Because the evidence base is weak and modest to moderate effects, at best, can be anticipated, WHO should promote rigorous evaluations of implementation strategies. What should be done at headquarters, by regional offices and in countries? • Adaptation and implementation of WHO guidelines should be done locally, at the national or sub-national level. • WHO headquarters and regional offices should support the development and evaluation of implementation strategies by local authorities

    Cost-Effectiveness Analysis of Administering Tranexamic Acid to Bleeding Trauma Patients Using Evidence from the CRASH-2 Trial

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    OBJECTIVE: To assess the cost effectiveness of giving tranexamic acid (TXA) to bleeding trauma patients in low, middle and high income settings. METHODS: The CRASH-2 trial showed that TXA administration reduces the risk of death in bleeding trauma patients with a small but statistically significant increase in non-intensive care stay. A Markov model was used to assess the cost effectiveness of TXA in Tanzania, India and the United Kingdom (UK). The health outcome was the number of life years gained (LYs). Two costs were considered: the cost of administering TXA and the cost of additional days in hospital. Cost data were obtained from hospitals, World Health Organization (WHO) database and UK reference costs. Cost-effectiveness was measured in international dollars ()perLY.Bothdeterministicandprobabilisticsensitivityanalyseswereperformedtotesttherobustnessoftheresultstomodelassumptions.FINDINGS:AdministeringTXAtobleedingtraumapatientswithinthreehoursofinjurysavedanestimated372,315and755LYsper1,000traumapatientsinTanzania,IndiaandtheUKrespectively.ThecostofgivingTXAto1,000patientswas) per LY. Both deterministic and probabilistic sensitivity analyses were performed to test the robustness of the results to model assumptions. FINDINGS: Administering TXA to bleeding trauma patients within three hours of injury saved an estimated 372, 315 and 755 LYs per 1,000 trauma patients in Tanzania, India and the UK respectively. The cost of giving TXA to 1,000 patients was 17,483 in Tanzania, 19,550inIndiaand19,550 in India and 30,830 in the UK. The incremental cost of giving TXA versus not giving TXA was 18,025inTanzania,18,025 in Tanzania, 20,670 in India and 48,002intheUK.TheestimatedincrementalcostperLYgainedofadministeringTXAis48,002 in the UK. The estimated incremental cost per LY gained of administering TXA is 48, 66and66 and 64 in Tanzania, India and the UK respectively. CONCLUSION: Early administration of TXA to bleeding trauma patients is likely to be highly cost effective in low, middle and high income settings. TRIAL REGISTRATION: This paper uses data collected by the CRASH 2 trial: Controlled-Trials.com ISRCTN86750102, Clinicaltrials.govNCT00375258 and South African Clinical Trial Register DOH-27-0607-1919

    Improving the use of research evidence in guideline development: 13. Applicability, transferability and adaptation

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    BACKGROUND: The World Health Organization (WHO), like many other organisations around the world, has recognised the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the thirteenth of a series of 16 reviews that have been prepared as background for advice from the WHO Advisory Committee on Health Research to WHO on how to achieve this. OBJECTIVES: We reviewed the literature on applicability, transferability, and adaptation of guidelines. METHODS: We searched five databases for existing systematic reviews and relevant primary methodological research. We reviewed the titles of all citations and retrieved abstracts and full text articles if the citations appeared relevant to the topic. We checked the reference lists of articles relevant to the questions and used snowballing as a technique to obtain additional information. We used the definition "coming from, concerning or belonging to at least two or all nations" for the term international. Our conclusions are based on the available evidence, consideration of what WHO and other organisations are doing and logical arguments. KEY QUESTIONS AND ANSWERS: We did not identify systematic reviews addressing the key questions. We found individual studies and projects published in the peer reviewed literature and on the Internet. Should WHO develop international recommendations? • Resources for developing high quality recommendations are limited. Internationally developed recommendations can facilitate access to and pooling of resources, reduce unnecessary duplication, and involve international scientists. • Priority should be given to international health problems and problems that are important in low and middle-income countries, where these advantages are likely to be greatest. • Factors that influence the transferability of recommendations across different settings should be considered systematically and flagged, including modifying factors, important variation in needs, values, costs and the availability of resources. What should be done centrally and locally? • The preparation of systematic reviews and evidence profiles should be coordinated centrally, in collaboration with organizations that produce systematic reviews. Centrally developed evidence profiles should be adaptable to specific local circumstances. • Consideration should be given to models that involve central coordination with work being undertaken by centres located throughout the world. • While needs, availability of resources, costs, the presence of modifying factors and values need to be assessed locally, support for undertaking these assessments may be needed to make guidelines applicable. • WHO should provide local support for adapting and implementing recommendations by developing tools, building capacity, learning from international experience, and through international networks that support evidence-informed health policies, such as the Evidence-informed Policy Network (EVIPNet). How should recommendations be adapted? • WHO should provide detailed guidance for adaptation of international recommendations. • Local adaptation processes should be systematic and transparent, they should involve stakeholders, and they should report the key factors that influence decisions, including those flagged in international guidelines, and the reasons for any modifications that are made
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