744 research outputs found

    Can we ‘seize’ the gut microbiota to treat epilepsy?

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    The gut-microbiota, the complex intestinal microbial ecosystem essential to health, is an emerging concept in medicine. Several studies demonstrate a microbiota-gut-brain bidirectional connection via neural, endocrine, metabolic and immune pathways. Accordingly, the gut microbiota has a crucial role in modulating intestinal permeability, to alter local/peripheral immune responses and in production of essential metabolites and neurotransmitters. Its alterations may consequently influence all these pathways that contribute to neuronal hyper-excitability and mirrored neuroinflammation in epilepsy and similarly other neurological conditions. Indeed, pre- and clinical studies support the role of the microbiome in pathogenesis, seizure modulation and responses to treatment in epilepsy. Up to now, researchers have focussed attention above all on the brain to develop antiepileptic treatments, but considering the microbiome, could extend our possibilities for developing novel therapies in the future. We provide here a comprehensive overview of the available data on the potential role of gut microbiota in the physiopathology and therapy of epilepsy and the supposed underlying mechanisms

    Haemodynamics and flow modification stents for peripheral arterial disease:a review

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    Endovascular stents are widely used for the treatment of peripheral arterial disease (PAD). However, the development of in-stent restenosis and downstream PAD progression remain a challenge. Stent revascularisation of PAD causes arterial trauma and introduces abnormal haemodynamics, which initiate complicated biological processes detrimental to the arterial wall. The interaction between stent struts and arterial cells in contact, and the blood flow field created in a stented region, are highly affected by stent design. Spiral flow is known as a normal physiologic characteristic of arterial circulation and is believed to prevent the development of flow disturbances. This secondary flow motion is lost in atheromatous disease and its re-introduction after endovascular treatment of PAD has been suggested as a method to induce stabilised and coherent haemodynamics. Stent designs able to generate spiral flow may support endothelial function and therefore increase patency rates. This review is focused on secondary flow phenomena in arteries and the development of flow modification stent technologies for the treatment of PAD

    A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite

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    The study of radiation effects in solids is important for the development of 'radiation-resistant' materials for fission-reactor applications'. The effects of heavy-ion irradiation in the isostructural orthosilicates zircon (ZrSiO4), hafnon (HfSiO4) and thorite (ThSiO4) are particularly important because these minerals are under active investigation for use as a waste form for plutonium-239 resulting from the dismantling of nuclear weapons(2-4). During ion irradiation, localized 'cascades' of displaced atoms can form as a result of ballistic collisions in the target material, and the temperature inside these regions may for a short time exceed the bulk melting temperature. Whether these cascades do indeed generate a localized liquid state(5-8) has, however, remained unclear. Here we investigate the irradiation-induced decomposition of zircon and hafnon, and find evidence for formation of a liquidlike state in the displacement cascades. Our results explain the frequent occurrence of ZrO2 in natural amorphous zircong(9-12) Moreover, we conclude that zircon-based nuclear waste forms should be maintained within strict temperature Limits, to avoid potentially detrimental irradiation-induced amorphization or phase decomposition of the zircon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62853/1/395056a0.pd

    Development and characterisation of a large diameter decellularised vascular allograft

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    The aims of this study were to develop a biological large diameter vascular graft by decellularisation of native human aorta to remove the immunogenic cells whilst retaining the essential biomechanical, and biochemical properties for the ultimate benefit of patients with infected synthetic grafts. Donor aortas (n = 6) were subjected to an adaptation of a propriety decellularisation process to remove the cells and acellularity assessed by histological analysis and extraction and quantification of total DNA. The biocompatibility of the acellular aortas was determined using standard contact cytotoxicity tests. Collagen and denatured collagen content of aortas was determined and immunohistochemistry was used to determine the presence of specific extracellular matrix proteins. Donor aortas (n = 6) were divided into two, with one half subject to decellularisation and the other half retained as native tissue. The native and decellularised aorta sections were then subject to uniaxial tensile testing to failure [axial and circumferential directions] and suture retention testing. The data was compared using a paired t-test. Histological evaluation showed an absence of cells in the treated aortas and retention of histoarchitecture including elastin content. The decellularised aortas had less than 15 ng mg¯¹ total DNA per dry weight (mean 94% reduction) and were biocompatible as determined by in vitro contact cytotoxicity tests. There were no gross changes in the histoarchitecture [elastin and collagen matrix] of the acellular aortas compared to native controls. The decellularisation process also reduced calcium deposits within the tissue. The uniaxial tensile and suture retention testing revealed no significant differences in the material properties (p > 0.05) of decellularised aorta. The decellularisation procedure resulted in minimal changes to the biological and biomechanical properties of the donor aortas. Acellular donor aorta has excellent potential for use as a large diameter vascular graft

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Influence of Interferon beta treatment on quality of life in multiple sclerosis patients

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    BACKGROUND: Interferon-beta (IFN-β) shows beneficial effect on the course of multiple sclerosis (MS), nevertheless its route and frequency of administration and side effects might impact negatively the quality of life (QoL) of MS patients. The objective of this study was to evaluate the influence of IFN-β on QoL in MS patients. METHODS: Seventy-seven disease modifying treatment (DMT) free and 41 IFN-β treated MS patients were evaluated. QoL, assessed by MSQoL-54, was related to IFN-β treatment and to clinical and demographic parameters at baseline and after two years. Multivariate hierarchical linear model for repeated measurements was used. RESULTS: Treated patients showed a younger age, a lower disease duration and a higher relapse rate in the two years preceding study entry. At inclusion time treated and untreated patients did not differ in relapse rate, expanded disability status scale (EDSS), fatigue, depression, physical and mental QoL. IFN-β did not influence QoL at inclusion time, but when QoL was evaluated after two years, treatment negatively affected mental QoL. Depression and fatigue negatively influenced physical and mental QoL both at baseline and after two years. EDSS correlated with a poor physical QoL only at baseline. CONCLUSION: IFN-β had a negative impact on QoL over the time in MS patients, influencing mainly mental QoL. The impairment of QoL in MS was strongly associated with increasing fatigue and depression, whereas clinical disability had a minor unfavourable role

    Selecting Indicator Portfolios for Marine Species and Food Webs: A Puget Sound Case Study

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    Ecosystem-based management (EBM) has emerged as a promising approach for maintaining the benefits humans want and need from the ocean, yet concrete approaches for implementing EBM remain scarce. A key challenge lies in the development of indicators that can provide useful information on ecosystem status and trends, and assess progress towards management goals. In this paper, we describe a generalized framework for the methodical and transparent selection of ecosystem indicators. We apply the framework to the second largest estuary in the United States – Puget Sound, Washington – where one of the most advanced EBM processes is currently underway. Rather than introduce a new method, this paper integrates a variety of familiar approaches into one step-by-step approach that will lead to more consistent and reliable reporting on ecosystem condition. Importantly, we demonstrate how a framework linking indicators to policy goals, as well as a clearly defined indicator evaluation and scoring process, can result in a portfolio of useful and complementary indicators based on the needs of different users (e.g., policy makers and scientists). Although the set of indicators described in this paper is specific to marine species and food webs, we provide a general approach that could be applied to any set of management objectives or ecological system

    Statistical analyses and quality of individual participant data network meta-analyses were suboptimal: a cross-sectional study

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    Background Network meta-analyses using individual participant data (IPD-NMAs) have been increasingly used to compare the effects of multiple interventions. Although there have been many studies on statistical methods for IPD-NMAs, it is unclear whether there are statistical defects in published IPD-NMAs and whether the reporting of statistical analyses has improved. This study aimed to investigate statistical methods used and assess the reporting and methodological quality of IPD-NMAs. Methods We searched four bibliographic databases to identify published IPD-NMAs. The methodological quality was assessed using AMSTAR-2 and reporting quality assessed based on PRISMA-IPD and PRISMA-NMA. We performed stratified analyses and correlation analyses to explore the factors that might affect quality. Results We identified 21 IPD-NMAs. Only 23.8% of the included IPD-NMAs reported statistical techniques used for missing participant data, 42.9% assessed the consistency, and none assessed the transitivity. None of the included IPD-NMAs reported sources of funding for trials included, only 9.5% stated pre-registration of protocols, and 28.6% assessed the risk of bias in individual studies. For reporting quality, compliance rates were lower than 50.0% for more than half of the items. Less than 15.0% of the IPD-NMAs reported data integrity, presented the network geometry, or clarified risk of bias across studies. IPD-NMAs with statistical or epidemiological authors often better assessed the inconsistency (P = 0.017). IPD-NMAs with a priori protocol were associated with higher reporting quality in terms of search (P = 0.046), data collection process (P = 0.031), and syntheses of results (P = 0.006). Conclusions The reporting of statistical methods and compliance rates of methodological and reporting items of IPD-NMAs were suboptimal. Authors of future IPD-NMAs should address the identified flaws and strictly adhere to methodological and reporting guidelines
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