239 research outputs found

    The neuropsychology needs of a hyper-acute stroke unit

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    BACKGROUND AND AIM: Guidelines recommend routine assessment and management of mood and cognition after stroke, but little is known about the value or feasibility of providing neuropsychology input during the hyper-acute period. We aimed to identify and describe the extent and nature of neuropsychological needs and to investigate the feasibility of providing direct neuropsychology input within a hyper-acute setting. METHODS: Over a 7-month period, Multidisciplinary Team (MDT) members of a central London Hyper-Acute Stroke Unit (HASU) identified stroke patients who they believed would benefit from neuropsychology input, and categorised the nature of neuropsychology intervention required. We examined the demographic and clinical characteristics of the patients identified and the type of intervention required. RESULTS: 23% of patients (101/448) were identified as requiring neuropsychology input. Patients deemed to require input were younger, more likely to be male and more functionally disabled than those not requiring input. Cognitive assessment was the main identified need (93%) followed by mood (29%) and family support (9%). 30% of patients required two types of intervention. During a pilot of neuropsychology provision, 17 patients were seen; 15 completed a full cognitive assessment. All patients assessed presented with cognitive impairment despite three being deemed cognitively intact (> standardised cut-off) using a cognitive screening tool. CONCLUSION: We showed that direct neuropsychology input on a HASU is necessary for complex and varied interventions involving cognition, mood and family support. Furthermore, input is feasible and useful in detecting cognitive impairment not revealed by screening instruments

    Additional Queen Square (QS) screening items improve the test accuracy of the Montreal Cognitive Assessment (MoCA) after acute stroke

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    BACKGROUND The Montreal Cognitive Assessment (MoCA) is a popular cognitive screening tool used in stroke, but lacks sensitivity for detecting impairment in stroke-relevant domains of processing speed, non-verbal memory and executive functions. Our aim was to assess whether the test accuracy of the MoCA can be improved with additional tailored screening items targeting these three domains. METHODS We included 196 patients admitted to an acute stroke unit at the National Hospital for Neurology and Neurosurgery, Queen Square (QS), London. Participants completed the MoCA as well as a series of additional QS-screening items designed to assess speed of processing, non-verbal memory and executive functions. Performance on the MoCA and QS screening items was compared with performance on “gold standard” neuropsychological assessment. RESULTS In our sample, 22% of patients were classified as “cognitively intact” on the traditional MoCA alone (≥ 25). However, when tested on the QS-screening items, 40% of these patients failed on speed of processing, 56% failed on non-verbal memory and 26% failed on executive functions. Compared with neuropsychological assessment, the QS-screening items had good sensitivity (QS-Speed: 0.85; QS-Vis: 0.71; QS-EF: 0.73) and modest specificity (QS-Speed: 0.59; QS-Vis: 0.39; QS-EF: 0.54), regardless of stroke lateralisation. CONCLUSION Additional screening items detected impairments in speed of processing, non-verbal memory and executive functions over and above those captured using the standard MoCA. The use of these QS-screening items improves the detection of post-stroke cognitive deficits in domains not adequately covered by the standard MoCA

    The Chicken Yolk Sac IgY Receptor, a Mammalian Mannose Receptor Family Member, Transcytoses IgY across Polarized Epithelial Cells

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    In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds

    Integrated processing of sugarcane bagasse : arabinoxylan extraction integrated with ethanol production.

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    The authors gratefully acknowledge the funding for “Project POC02_NOV 14 Campbell” from the Lignocellulosic Biorefinery Network (LBNet), funded by the Biotechnology and Biological Sciences Research Council (BBSRC).A proof-of-concept project compared extraction of arabinoxylans (AX) from sugarcane bagasse and wheat bran via alkaline hydrogen peroxide followed by enzyme-assisted extraction with combinations of feruloyl esterases and a xylanase. Bagasse contains comparable amounts of AX to wheat bran, but with a much lower arabinoxylan substitution on the xylan backbone (A:X ratio of around 0.2 compared with 0.6 for wheat bran), hence offering AX products with distinctive functionality and potential end uses. In the current work, bagasse released its AX more readily than wheat bran, and released a wider range of molecular weights. Use of feruloyl esterase and xylanase enzymes on their own or following alkaline peroxide extraction did not enhance AX release substantially; however, the xylanase appeared to be effective at reducing the size of AX molecules, and there is scope to optimise the effects of enzymes to produce specific AX product fractions. As bagasse frequently arises within the context of bioethanol production, integration of AX extraction with ethanol production could allow economic production of a portfolio of AX products, as has been demonstrated in principle for AX co-production in a wheat ethanol plant.PostprintPeer reviewe

    Characteristics of ischaemic stroke associated with COVID-19

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    Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is associated with coagulopathy causing venous and arterial thrombosis.1 2 Recent data from the pandemic epicentre in Wuhan, China, reported neurological complications in 36% of 214 patients with COVID-19; acute cerebrovascular disease (mainly ischaemic stroke) was more common among 88 patients with severe COVID-19 than those with non-severe disease (5.7% vs 0.8%).3 However, the mechanisms, phenotype and optimal management of ischaemic stroke associated with COVID-19 remain uncertain. We describe the demographic, clinical, radiological and laboratory characteristics of six consecutive patients assessed between 1st and 16th April 2020 at the National Hospital for Neurology and Neurosurgery, Queen Square, London, UK, with acute ischaemic stroke and COVID-19 (confirmed by reverse-transcriptase PCR (RT-PCR)) (table 1). All six patients had large vessel occlusion with markedly elevated D-dimer levels (≥1000μg/L). Three patients had multiterritory infarcts, two had concurrent venous thrombosis, and, in two, ischaemic strokes occurred despite therapeutic anticoagulation

    Shifting microbial communities sustain multiyear iron reduction and methanogenesis in ferruginous sediment incubations

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    This is the peer reviewed version of the following article: Bray, MS, Wu, J, Reed, BC, et al. Shifting microbial communities sustain multiyear iron reduction and methanogenesis in ferruginous sediment incubations. Geobiology. 2017; 15: 678– 689. https://doi.org/10.1111/gbi.12239, which has been published in final form at https://doi.org/10.1111/gbi.12239. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.Reactive Fe(III) minerals can influence methane (CH4) emissions by inhibiting microbial methanogenesis or by stimulating anaerobic CH4 oxidation. The balance between Fe(III) reduction, methanogenesis, and CH4 oxidation in ferruginous Archean and Paleoproterozoic oceans would have controlled CH4 fluxes to the atmosphere, thereby regulating the capacity for CH4 to warm the early Earth under the Faint Young Sun. We studied CH4 and Fe cycling in anoxic incubations of ferruginous sediment from the ancient ocean analogue Lake Matano, Indonesia, over three successive transfers (500 days in total). Iron reduction, methanogenesis, CH4 oxidation, and microbial taxonomy were monitored in treatments amended with ferrihydrite or goethite. After three dilutions, Fe(III) reduction persisted only in bottles with ferrihydrite. Enhanced CH4 production was observed in the presence of goethite, highlighting the potential for reactive Fe(III) oxides to inhibit methanogenesis. Supplementing the media with hydrogen, nickel and selenium did not stimulate methanogenesis. There was limited evidence for Fe(III)-dependent CH4 oxidation, although some incubations displayed CH4-stimulated Fe(III) reduction. 16S rRNA profiles continuously changed over the course of enrichment, with ultimate dominance of unclassified members of the order Desulfuromonadales in all treatments. Microbial diversity decreased markedly over the course of incubation, with subtle differences between ferrihydrite and goethite amendments. These results suggest that Fe(III) oxide mineralogy and availability of electron donors could have led to spatial separation of Fe(III)-reducing and methanogenic microbial communities in ferruginous marine sediments, potentially explaining the persistence of CH4 as a greenhouse gas throughout the first half of Earth history

    A new perspective in bio-refining : Levoglucosenone and cleaner lignin from waste biorefinery hydrolysis lignin by selective conversion of residual saccharides

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    An unexpected opportunity is reported to improve the sustainability of biorefineries whereby 8 wt% levoglucosenone (LGE) can be derived from unconverted saccharides in a lignin-rich biorefinery waste stream in a highly selective fashion (>90%). Additionally, in the process a purer lignin is obtained which can be used for further processing or materials applications. LGE is a valuable and versatile product with a plethora of applications
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