332 research outputs found

    UDP-sugars activate P2Y 14 receptors to mediate vasoconstriction of the porcine coronary artery

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    Aims UDP-sugars can act as extracellular signalling molecules, but relatively little is known about their cardiovascular actions. The P2Y14 receptor is a Gi/o-coupled receptor which is activated by UDP-glucose and related sugar nucleotides. In this study we sought to investigate whether P2Y14 receptors are functionally expressed in the porcine coronary artery using a selective P2Y14 receptor agonist, MRS2690, and a novel selective P2Y14 receptor antagonist, PPTN (4,7-disubstituted naphthoic acid derivative). Methods and results Isometric tension recordings were used to evaluate the effects of UDP-sugars in porcine isolated coronary artery segments. The effects of the P2 receptor antagonists suramin and PPADS, the P2Y14 receptor antagonist PPTN, and the P2Y6 receptor antagonist MRS2578, were investigated. Measurement of vasodilator-stimulated phosphoprotein (VASP) phosphorylation using flow cytometry was used to assess changes in cAMP levels. UDP-glucose, UDP-glucuronic acid UDP-N-acetylglucosamine (P2Y14 receptor agonists), elicited concentration-dependent contractions in the porcine coronary artery. MRS2690 was a more potent vasoconstrictor than the UDP-sugars. Concentration dependent contractile responses to MRS2690 and UDP-sugars were enhanced in the presence of forskolin (activator of cAMP), where the level of basal tone was maintained by addition of U46619, a thromboxane A2 mimetic. Contractile responses to MRS2690 were blocked by PPTN, but not by MRS2578. Contractile responses to UDP-glucose were also attenuated by PPTN and suramin, but not by MRS2578. Forskolin-induced VASP-phosphorylation was reduced in porcine coronary arteries exposed to UDP-glucose and MRS2690, consistent with P2Y14 receptor coupling to Gi/o proteins and inhibition of adenylyl cyclase activity. Conclusions Our data support a role of UDP-sugars as extracellular signalling molecules and show for the first time that they mediate contraction of porcine coronary arteries via P2Y14 receptors

    Clinical utility of remote platelet function measurement using P-selectin: assessment of aspirin, clopidogrel, and prasugrel and bleeding disorders

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    Vascular diseases such as myocardial infarction and ischemic stroke are associated with increased platelet function whilst the risk of recurrence is reduced by antiplatelet agents such as aspirin, clopidogrel, and prasugrel. However, some patients exhibit high platelet reactivity, especially with clopidogrel. Existing platelet function tests may not be ideal in that they can be expensive, are often time consuming, and measurements must be made near to the patient and within a few hours of blood collection. Platelet activation leads to translocation of P-selectin from alpha-granules to the cell surface. Following activation with arachidonic acid (which is blocked by aspirin) or adenosine diphosphate (inhibited by clopidogrel) and fixation, samples may be stored or posted to a laboratory performing flow cytometric quantification of platelet P-selectin expression. Acute myocardial infarction and ischemic stroke are associated with high platelet reactivity on clopidogrel in 6–58% of patients when assessed with P-selectin expression, and high reactivity was associated with an increased risk of recurrence after myocardial infarction. Use of P-selectin expression tests may also be of relevance to surgical and veterinary practice and the diagnosis of mild bleeding disorders. The present review explores this topic in further detail

    Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

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    Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Such delayed reporting does reduce the usefulness of such data for nature conservation when timely information about animal movements is required. To counter this problem we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (comprising speed of movement and turning angle calculated from fixes), allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data Automating the detection of both excursions and home range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal to inform conservationists and wider audiences. We recommend automated analysis, interpretation and communication of satellite tag and other ecological data to advance nature conservation research and practice

    Length of stay in asylum centres and mental health in asylum seekers: a retrospective study from Denmark

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    <p>Abstract</p> <p>Background</p> <p>The length of stay in asylum centres is generally mentioned as a possible health risk to asylum seekers. Medical staff working with asylum seekers has claimed that long lengths of stay in asylum centres might cause or aggravate mental disorders. We used records from a large, multiethnic group of asylum seekers to study if the incidence of mental disorders increased with length of stay.</p> <p>Methods</p> <p>The study population was asylum seekers in Danish asylum centres run by the Danish Red Cross. General medical care was provided by Red Cross staff who could refer selected cases to medical specialists. If an asylum seeker needed more than three specialist consultations for mental illness or five consultations for physical illness the referrals had to be approved by The Danish Immigration Service. Between July 2001 – December 2002 the Red Cross prospectively registered health related data on all new applications (n = 4516) to the Immigration Service regarding referrals to medical specialists. We used these records to analyse the association between length of stay in the asylum centres and overall rate of referral for mental disorders. Data was analysed using weighted linear regression.</p> <p>Results</p> <p>We found that referrals for mental disorders increased with length of stay in asylum centres in a large, multiethnic population of asylum seekers. The association was found in all the categories of psychiatric illness studied and for a majority of the nationality groups studied.</p> <p>Conclusion</p> <p>Length of stay in asylum centres was associated with an increase in referrals for mental disorders in a large, multiethnic group of asylum seekers. The present study supports the view that prolonged length of stay in an asylum centre is a risk factor for mental health. The risk of psychiatric illness among asylum seekers should be addressed by political and humanitarian means, giving prevention of illness the highest priority.</p

    The Herts and Minds study: Evaluating the effectiveness of Mentalization-Based Treatment (MBT) as an intervention for children in foster care with emotional and/or behavioural problems: a phase II, feasibility, randomised controlled trial.

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    Trial registration at https://doi.org/10.1186/ISRCTN90349442 © The Authors 2017. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Nick Midgley, Sarah Jane Besser, Helen Dye, Pasco Fearon, tim Gale, Kiri Jefferies-Sewell, Karen Irvine, Joyce Robinson, Solange Wyatt, David Wellsted and Sally Wood, 'The Herts and minds study: evaluating the effectiveness of mentalization-based treatment (MBT) as an intervention for children in foster care with emotional and/or behavioural problems: a phase II, feasibility, randomised controlled trial', Pilot and Feasibility Studies, Vol. 3(12, February 2017. The published version is available online at doi: 10.1186/s40814-017-0127-xBackground A significant proportion of children in the social care system in England present with mental health problems, with the majority experiencing some form of emotional and behavioural difficulties. The most effective treatments for these children are currently unknown, partly due to a lack of robust, controlled studies. Researchers have identified a number of obstacles to conducting well-designed research with this population, making the need to test the feasibility of a randomised controlled trial especially important. Methods/design This protocol outlines a two-arm, randomised control feasibility trial to explore the acceptability and credibility of mentalization-based treatment (MBT) as a treatment for reducing emotional and behavioural difficulties in looked after children and to test the possibility of addressing a number of methodological challenges to conducting high-quality research with this population. MBT is a relatively new intervention which, in the adaptation of the model tested here, includes many of the features of therapy identified in NICE guidelines as necessary to support children in care. The two arms are MBT and usual clinical care (UCC). The study will take place in Hertfordshire Partnership University NHS Foundation Trust with follow-up at 12 and 24 weeks. Discussion This study will aim to ascertain whether it is worthwhile and feasible to progress to testing the intervention in a full-scale definitive randomised controlled trial (RCT). This study therefore has the potential to improve our understanding of the obstacles to conducting high-quality research with this very vulnerable population, and in the medium term, could help to improve the stability of foster placements and the emotional well-being of children in care. Trial registration ISRCTN90349442Peer reviewe

    Dual Action of lysophosphatidate- functionalised titanium: Interactions with human (MG63) osteoblasts and methicillin resistant staphylococcus aureus

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    © 2015 Skindersoe et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Titanium (Ti) is a widely used material for surgical implants; total joint replacements (TJRs), screws and plates for fixing bones and dental implants are forged from Ti. Whilst Ti integrates well into host tissue approximately 10% of TJRs will fail in the lifetime of the patient through a process known as aseptic loosening. These failures necessitate revision arthroplasties which are more complicated and costly than the initial procedure. Finding ways of enhancing early (osseo)integration of TJRs is therefore highly desirable and continues to represent a research priority in current biomaterial design. One way of realising improvements in implant quality is to coat the Ti surface with small biological agents known to support human osteoblast formation and maturation at Ti surfaces. Lysophosphatidic acid (LPA) and certain LPA analogues offer potential solutions as Ti coatings in reducing aseptic loosening. Herein we present evidence for the successful bio-functionalisation of Ti using LPA. This modified Ti surface heightened the maturation of human osteoblasts, as supported by increased expression of alkaline phosphatase. These functionalised surfaces also deterred the attachment and growth of Staphylococcus aureus, a bacterium often associated with implant failures through sepsis. Collectively we provide evidence for the fabrication of a dual-action Ti surface finish, a highly desirable feature towards the development of next-generation implantable devices

    Ethical issues, research and vulnerability : gaining the views of children and young people in residential care

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    Children and young people in residential care are some of the most vulnerable in our society. They may have experienced violence and physical, sexual or emotional abuse. They may be involved in offending or the misuse of drugs and alcohol. They are separated from their families and have to cope with living in a group situation with other young people and staff members. Children and young people in residential care also possess strengths, competencies and resilience. We have much to learn from their experiences and perspectives, both generally and surrounding their time in care. This paper will address the ethical issues which arise from gaining the views of children and young people in residential care, drawing on the experience of carrying out three studies in particular (Kendrick et al. 2004, The development of a residential unit working with sexually aggressive young men. In: H.G. Eriksson and T. Tjelflaat, eds. Residential care: horizons for the new century. Aldershot: Ashgate, 38-55; Docherty et al. 2006, Designing with care: interior design and residential child care. Farm7 and SIRCC. http://www.sircc.strath.ac.uk/publications/Designing_with_Care.pdf; Steckley, L. and Kendrick, A., 2005. Physical restraint in residential child care: the experiences of young people and residential workers. Childhoods 2005: Children and Youth in Emerging and Transforming Societies, University of Oslo, Norway, 29 June-3 July 2005, Steckley and Kendrick 2007, Young people's experiences of physical restraint in residential care: subtlety and complexity in policy and practice. In: M. Nunno, L. Bullard and D. Day, eds. For our own safety: examining the safety of high-risk interventions for children and young people. Washington, DC: Child Welfare League of America, forthcoming). The paper will discuss: information, consent and choice about involvement in the research; confidentiality, privacy and safety. It will also explore some of the more complex issues of ethical good practice which arise from researching children in their own living space. The negotiation of children's time and space must be approached carefully, with consideration of their rights and wishes. Sensitivity to children and young people's priorities and preoccupations must be paramount

    Challenges to undertaking randomised trials with looked after children in social care settings.

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    BACKGROUND: Randomised controlled trials (RCTs) are widely viewed as the gold standard for assessing effectiveness in health research; however many researchers and practitioners believe that RCTs are inappropriate and un-doable in social care settings, particularly in relation to looked after children. The aim of this article is to describe the challenges faced in conducting a pilot study and phase II RCT of a peer mentoring intervention to reduce teenage pregnancy in looked after children in a social care setting. METHODS: Interviews were undertaken with social care professionals and looked after children, and a survey conducted with looked after children, to establish the feasibility and acceptability of the intervention and research design. RESULTS: Barriers to recruitment and in managing the intervention were identified, including social workers acting as informal gatekeepers; social workers concerns and misconceptions about the recruitment criteria and the need for and purpose of randomisation; resource limitations, which made it difficult to prioritise research over other demands on their time and difficulties in engaging and retaining looked after children in the study. CONCLUSIONS: The relative absence of a research infrastructure and culture in social care and the lack of research support funding available for social care agencies, compared to health organisations, has implications for increasing evidence-based practice in social care settings, particularly in this very vulnerable group of young people
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