159 research outputs found

    Transport mechanism of a glutamate transporter homologue GltPh.

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    Glutamate transporters are responsible for uptake of the neurotransmitter glutamate in mammalian central nervous systems. Their archaeal homologue GltPh, an aspartate transporter isolated from Pyrococcus horikoshii, has been the focus of extensive studies through crystallography, MD simulations and single-molecule FRET (smFRET). Here, we summarize the recent research progress on GltPh, in the hope of gaining some insights into the transport mechanism of this aspartate transporter

    Understanding self-harm in older adults: a qualitative study

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    Background Self-harm is the leading risk factor for suicide, with elevated rates reported amongst older populations. This study explores how older adults experience self-harm, identifying factors leading to self-harm. Methods Semi-structured interviews with older adults (≥ 60 years) engaging in self-harm and support workers from third sector services in England. Older adults were invited to participate in a follow-up interview. Interviews were recorded, transcribed verbatim and data analysed thematically. Ethical approval obtained from Keele University's Ethics Review Panel. A Patient Involvement group contributed to study design, data analysis and interpretation. Outcomes Between September 2017 to September 2018, 24 interviews were conducted involving 16 participants: nine older adults and seven support workers. Eight older adults consented to follow-up interviews. All older adults reported diagnoses of mental illness in addition to physical illness. Participants identified diverse stressors accumulating over the life-course leaving older adults particularly vulnerable to self-harm. Such stressors included adverse events, loss, interpersonal and health problems. A sense of shame and stigma amongst older people using self-harm to manage distress was also reported. Interpretation Self-harm is often concealed due to stigma and shame, being further accentuated amongst older adults, which may result in low levels of medical help-seeking behaviour for self-harm. Self-harm occurred along a spectrum of no-suicidal intent to high-levels of intent, suggesting self-harm holds different functions to older adults. Clinicians should be aware of the existence of self-harm in this age-group, and the heightened risk amongst those with comorbidities so adequate assessment, support and/or referral is provided

    Purification, crystallization and X-ray crystallographic analysis of a putative exopolyphosphatase from Zymomonas mobilis

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    Exopolyphosphatase (PPX) enzymes degrade inorganic polyphosphate (poly-P), which is essential for the survival of microbial cells in response to external stresses. In this study, a putative exopolyphosphatase from Zymomonas mobilis (ZmPPX) was crystallized. Crystals of the wild-type enzyme diffracted to 3.3 Å resolution and could not be optimized further. The truncation of 29 amino acids from the N-terminus resulted in crystals that diffracted to 1.8 Å resolution. The crystals belonged to space group C2, with unit-cell parameters a = 122.0, b = 47.1, c = 89.5 Å, α = γ = 90, β = 124.5°. An active-site mutant that crystallized in the same space group and with similar unit-cell parameters diffracted to 1.56 Å resolution. One molecule was identified per asymmetric unit. Analytical ultracentrifugation confirmed that ZmPPX forms a dimer in solution. It was confirmed that ZmPPX possesses exopolyphosphatase activity against a synthetic poly-P substrate.published_or_final_versio

    Patient and public involvement and engagement in a doctoral research project exploring self-harm in older adults

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    Background: The contribution of involving patients and public in health research is widely reported, particularly within mental health research. Less is written about such contributions to doctoral research. The research focus of this doctoral research, self-harm in older adults, was put forward by a Patient Public Involvement Engagement (PPIE) group, who contributed to its development. Aims: Critically reflect on the process, potential impact and identify challenges and opportunities in involving robust PPIE in a doctoral study. Methods: Three PPIE members contributed to a systematic review (SR) and a qualitative study through a series of four workshops to meet the aims of the study. PPIE contributed to developing the SR review questions, protocol, data analysis and dissemination of findings. For the qualitative study, they helped develop research questions, protocol, public-facing documentation, recruitment strategies and data analysis. Involvement followed the GRIPP2-SF reporting checklist. Results: PPIE enhanced methodological rigour, data analysis, interpretation and dissemination of findings. Challenges included lack of ethical guidance, time-related pressures and ensuring support for PPIE members. These were successfully managed through ongoing dialogue and regular communication. Conclusions: PPIE can enhance the quality and depth of doctoral research, as lived experiences shared by PPIE members add to research's components. Exposing early-career researchers to PPIE can build research cultures sensitive to PPIE's potential contribution and develop the expertise needed to avoid tokenistic involvement. Capturing lay perspectives is essential in mental health research to ensure research findings are accessible and that findings inform clinical practice. However, clear guidance on the ethical dimensions to PPIE is needed

    A novel and fast purification method for nucleoside transporters

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    Nucleoside transporters (NTs) play critical biological roles in humans, and to understand the molecular mechanism of nucleoside transport requires high-resolution structural information. However, the main bottleneck for structural analysis of NTs is the production of pure, stable, and high quality native protein for crystallization trials. Here we report a novel membrane protein expression and purification strategy, including construction of a high-yield membrane protein expression vector, and a new and fast purification protocol for NTs. The advantages of this strategy are the improved time efficiency, leading to high quality, active, stable membrane proteins, and the efficient use of reagents and consumables. Our strategy might serve as a useful point of reference for investigating NTs and other membrane proteins by clarifying the technical points of vector construction and improvements of membrane protein expression and purification. © 2016 Hao, Thomsen, Postis, Lesiuk, Sharples, Wang, Bartlam and Goldman.Peer reviewe

    The Role of Qualitative Research in Clinical Trial Development: The EASE Back Study

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    This article outlines the rationale for adopting a mixed methods approach within randomized controlled trials (RCTs) and explores challenges associated in doing so. Taking the example of the EASE Back feasibility and pilot study (Evaluating Acupuncture and Standard care for pregnant womEn with BACK pain: ISRCTN49955124), we detail why and how we operationalized a concurrent-sequential mixed methods research design. We present key findings from the exploratory research (focus groups and interviews) and explain how these were integrated with descriptive findings (a national survey of physical therapists) in order to inform and refine the design of the explanatory phase (the pilot RCT). We conclude with a discussion of lessons learned and implications for future research design and conduct

    Biomechanics of predator–prey arms race in lion, zebra, cheetah and impala

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    The fastest and most manoeuvrable terrestrial animals are found in savannah habitats, where predators chase and capture running prey. Hunt outcome and success rate are critical to survival, so both predator and prey should evolve to be faster and/or more manoeuvrable. Here we compare locomotor characteristics in two pursuit predator–prey pairs, lion–zebra and cheetah–impala, in their natural savannah habitat in Botswana. We show that although cheetahs and impalas were universally more athletic than lions and zebras in terms of speed, acceleration and turning, within each predator–prey pair, the predators had 20% higher muscle fibre power than prey, 37% greater acceleration and 72% greater deceleration capacity than their prey. We simulated hunt dynamics with these data and showed that hunts at lower speeds enable prey to use their maximum manoeuvring capacity and favour prey survival, and that the predator needs to be more athletic than its prey to sustain a viable success rate

    Patients’ and clinicians’ perspectives on a ‘fast-track’ pathway for patients with sciatica in primary care: qualitative findings from the SCOPiC stratified care trial

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    BackgroundSciatica is common and associated with significant impacts for the individual and society. The SCOPiC randomised controlled trial (RCT) (trial registration: ISRCTN75449581) tested stratified primary care for sciatica by subgrouping patients into one of three groups based on prognostic and clinical indicators. Patients in one group were ‘fast-tracked’ for a magnetic resonance imaging (MRI) scan and spinal specialist opinion. This paper reports qualitative research exploring patients’ and clinicians’ perspectives on the acceptability of this ‘fast-track’ pathway.MethodsSemi-structured interviews were conducted with 20 patients and 20 clinicians (general practitioners, spinal specialist physiotherapists, spinal surgeons). Data were analysed thematically and findings explored using Normalisation Process Theory (NPT) and ‘boundary objects’ concept.ResultsWhilst the ‘fast-track’ pathway achieved a degree of ‘coherence’ (i.e. made sense) to both patients and clinicians, particularly in relation to providing early reassurance based on MRI scan findings, it was less ‘meaningful’ to some clinicians for managing patients with acute symptoms, reflecting a reluctance to move away from the usual ‘stepped care’ approach. Both groups felt a key limitation of the pathway was that it did not shorten patient waiting times between their spinal specialist consultation and further treatments.ConclusionFindings contribute new knowledge about patients’ and clinicians’ perspectives on the role of imaging and spinal specialist opinion in the management of sciatica, and provide important insights for understanding the ‘fast-track’ pathway, as part of the stratified care model tested in the RCT.Future research into the early referral of patients with sciatica for investigation and specialist opinion should include strategies to support clinician behaviour change; as well as take into account the role of imaging in providing reassurance to patients with severe symptoms in cases where imaging reveals a clear explanation for the patient’s pain, and where this is accompanied by a thorough explanation from a trusted clinical expert
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