145 research outputs found

    H+/K+ ATPase activity is required for biomineralization in sea urchin embryos

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    AbstractThe bioelectrical signatures associated with regeneration, wound healing, development, and cancer are changes in the polarization state of the cell that persist over long durations, and are mediated by ion channel activity. To identify physiologically relevant bioelectrical changes that occur during normal development of the sea urchin Lytechinus variegatus, we tested a range of ion channel inhibitors, and thereby identified SCH28080, a chemical inhibitor of the H+/K+ ATPase (HKA), as an inhibitor of skeletogenesis. In sea urchin embryos, the primary mesodermal lineage, the PMCs, produce biomineral in response to signals from the ectoderm. However, in SCH28080-treated embryos, aside from randomization of the left-right axis, the ectoderm is normally specified and differentiated, indicating that the block to skeletogenesis observed in SCH28080-treated embryos is PMC-specific. HKA inhibition did not interfere with PMC specification, and was sufficient to block continuing biomineralization when embryos were treated with SCH28080 after the initiation of skeletogenesis, indicating that HKA activity is continuously required during biomineralization. Ion concentrations and voltage potential were abnormal in the PMCs in SCH28080-treated embryos, suggesting that these bioelectrical abnormalities prevent biomineralization. Our results indicate that this effect is due to the inhibition of amorphous calcium carbonate precipitation within PMC vesicles

    Development of a rapid immunoassay for human pathogenic markers

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    A demand exists for a fast, sensitive, reliable and economical test for pyogenic sepsis that provides a “real time” bed-side assessment. Detection of significant intra-abdominal sepsis can be particularly problematic in the ICU setting and in patients with multi-system organ failure. Lysozyme, first reported by Fleming (1922), is a bacteriolytic enzyme released during phagocytosis. Previous studies have shown significant correlation between lysozyme levels and the presence of intra-abdominal abscess in both animals and humans. A method which determines and quantifies lysozyme as part of an assessment of an acutely ill patient in whom major sepsis is suspected; would significantly aid diagnosis and prescription of the most effective form of treatment. To date measurement of lysozyme has been by turbidometry, with consequent poor sensitivity and reliability. Other methods of assay include fluorescence, radial immunodiffussion and enzyme linked immunosorbent assay (ELISA). This study reports a modified ELISA technique which provides a cheap, sensitive and reliable method of lysozyme determination, producing results in <100 minutes. The ELISA has been tested with ~200 clinical samples provided by the patients at the Great Western Hospital, Swindon. Two ELIFA techniques were also developed for lysozyme and E.coli detection. These techniques also provide a cheap and rapid alternative to the more traditional immunoassays. Results from the ELIFA and mini-ELIFA were obtained qualitatively after only 10 minutes. An SPR detection technique was also devised. The BIAcore 3000 was used to create a biosensor for serum lysozyme using an artificial receptor in the form of an aptamer. This system was tested with clinical serum samples, is reusable and took <80 minutes to immobilise a ligand on a blank sensor and analyse a serum sample for lysozyme. Although further research and development is required on the mini-ELIFA and lysozyme biosensor, the ELISA detection system may prove a useful tool in the diagnosis of sepsis in critically ill patients.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    The CO-produced Psychosocial INtervention delivered by GPs to young people after self-harm (COPING): protocol for a feasibility study

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    BackgroundSelf-harm in young people is a growing concern and reducing rates a global priority. General practitioners (GPs) can intervene early after self-harm but there are no effective treatments presently available. We developed the GP-led COPING intervention, in partnership with young people with lived experience and GPs, to be delivered to young people 16–25 years across two consultations. This study aims to examine the feasibility and acceptability of conducting a fully powered effectiveness trial of the COPING intervention in NHS general practice.MethodsThis will be a mixed-methods external non-randomised before-after single arm feasibility study in NHS general practices in the West Midlands, England. Patients aged 16–25 years who have self-harmed in the last 12 months will be eligible to receive COPING. Feasibility outcomes will be recruitment rates, intervention delivery, retention rates, and completion of follow-up outcome measures. All participants will receive COPING with a target sample of 31 with final follow-up data collection at six months from baseline. Clinical data such as self-harm repetition will be collected. A nested qualitative study and national survey of GPs will explore COPING acceptability, deliverability, implementation, and likelihood of contamination.DiscussionBrief GP-led interventions for young people after self-harm are needed and address national guideline and policy recommendations. This study of the COPING intervention will assess whether a main trial is feasible

    Evaluating pharmacological THRomboprophylaxis in Individuals undergoing superficial endoVEnous treatment across NHS and private clinics in the UK:a multi-centre, assessor-blind, randomised controlled trial-THRIVE trial

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    INTRODUCTION: Endovenous therapy is the first choice management for symptomatic varicose veins in NICE guidelines, with 56-70 000 procedures performed annually in the UK. Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a known complication of endovenous therapy, occurring at a rate of up to 3.4%. Despite 73% of UK practitioners administering pharmacological thromboprophylaxis to reduce VTE, no high-quality evidence supporting this practice exists. Pharmacological thromboprophylaxis may have clinical and cost benefit in preventing VTE; however, further evidence is needed. This study aims to establish whether when endovenous therapy is undertaken: a single dose or course of pharmacological thromboprophylaxis alters the risk of VTE; pharmacological thromboprophylaxis is associated with an increased rate of bleeding events; pharmacological prophylaxis is cost effective.METHODS AND ANALYSIS: A multi-centre, assessor-blind, randomised controlled trial (RCT) will recruit 6660 participants from 40 NHS and private sites across the UK. Participants will be randomised to intervention (single dose or extended course of pharmacological thromboprophylaxis plus compression) or control (compression alone). Participants will undergo a lower limb venous duplex ultrasound scan at 21-28 days post-procedure to identify asymptomatic DVT. The duplex scan will be conducted locally by blinded assessors. Participants will be contacted remotely for follow-up at 7 days and 90 days post-procedure. The primary outcome is imaging-confirmed lower limb DVT with or without symptoms or PE with symptoms within 90 days of treatment. The main analysis will be according to the intention-to-treat principle and will compare the rates of VTE at 90 days, using a repeated measures analysis of variance, adjusting for any pre-specified strongly prognostic baseline covariates using a mixed effects logistic regression.ETHICS AND DISSEMINATION: Ethical approval was granted by Brent Research Ethics Committee (22/LO/0261). Results will be disseminated in a peer-reviewed journal and presented at national and international conferences.TRIAL REGISTRATION NUMBER: ISRCTN18501431.</p

    Socio-cultural influences on the behaviour of South Asian women with diabetes in pregnancy: qualitative study using a multi-level theoretical approach

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    BACKGROUND: Diabetes in pregnancy is common in South Asians, especially those from low-income backgrounds, and leads to short-term morbidity and longer-term metabolic programming in mother and offspring. We sought to understand the multiple influences on behaviour (hence risks to metabolic health) of South Asian mothers and their unborn child, theorise how these influences interact and build over time, and inform the design of culturally congruent, multi-level interventions. METHODS: Our sample for this qualitative study was 45 women of Bangladeshi, Indian, Sri Lankan, or Pakistani origin aged 21-45 years with a history of diabetes in pregnancy, recruited from diabetes and antenatal services in two deprived London boroughs. Overall, 17 women shared their experiences of diabetes, pregnancy, and health services in group discussions and 28 women gave individual narrative interviews, facilitated by multilingual researchers, audiotaped, translated, and transcribed. Data were analysed using the constant comparative method, drawing on sociological and narrative theories. RESULTS: Key storylines (over-arching narratives) recurred across all ethnic groups studied. Short-term storylines depicted the experience of diabetic pregnancy as stressful, difficult to control, and associated with negative symptoms, especially tiredness. Taking exercise and restricting diet often worsened these symptoms and conflicted with advice from relatives and peers. Many women believed that exercise in pregnancy would damage the fetus and drain the mother's strength, and that eating would be strength-giving for mother and fetus. These short-term storylines were nested within medium-term storylines about family life, especially the cultural, practical, and material constraints of the traditional South Asian wife and mother role and past experiences of illness and healthcare, and within longer-term storylines about genetic, cultural, and material heritage - including migration, acculturation, and family memories of food insecurity. While peer advice was familiar, meaningful, and morally resonant, health education advice from clinicians was usually unfamiliar and devoid of cultural meaning. CONCLUSIONS: 'Behaviour change' interventions aimed at preventing and managing diabetes in South Asian women before and during pregnancy are likely to be ineffective if delivered in a socio-cultural vacuum. Individual education should be supplemented with community-level interventions to address the socio-material constraints and cultural frames within which behavioural 'choices' are made

    A randomised trial of the effect of omega-3 polyunsaturated fatty acid supplements on the human intestinal microbiota

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    Objective; Omega-3 polyunsaturated fatty acids (PUFAs) have anticolorectal cancer (CRC) activity. The intestinal microbiota has been implicated in colorectal carcinogenesis. Dietary omega-3 PUFAs alter the mouse intestinal microbiome compatible with antineoplastic activity. Therefore, we investigated the effect of omega-3 PUFA supplements on the faecal microbiome in middle-aged, healthy volunteers (n=22). Design A randomised, open-label, cross-over trial of 8 weeks’ treatment with 4 g mixed eicosapentaenoic acid/docosahexaenoic acid in two formulations (soft-gel capsules and Smartfish drinks), separated by a 12-week ‘washout’ period. Faecal samples were collected at five time-points for microbiome analysis by 16S ribosomal RNA PCR and Illumina MiSeq sequencing. Red blood cell (RBC) fatty acid analysis was performed by liquid chromatography tandem mass spectrometry. Results; Both omega-3 PUFA formulations induced similar changes in RBC fatty acid content, except that drinks were associated with a larger, and more prolonged, decrease in omega-6 PUFA arachidonic acid than the capsule intervention (p=0.02). There were no significant changes in α or β diversity, or phyla composition, associated with omega-3 PUFA supplementation. However, a reversible increased abundance of several genera, including Bifidobacterium, Roseburia and Lactobacillus was observed with one or both omega-3 PUFA interventions. Microbiome changes did not correlate with RBC omega-3 PUFA incorporation or development of omega-3 PUFA-induced diarrhoea. There were no treatment order effects. Conclusion; Omega-3 PUFA supplementation induces a reversible increase in several short-chain fatty acid-producing bacteria, independently of the method of administration. There is no simple relationship between the intestinal microbiome and systemic omega-3 PUFA exposure. Trial registration number; ISRCTN18662143

    Longitudinal clusters of pain and stiffness in polymyalgia rheumatica: 2-year results from the PMR Cohort study

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    Objectives. To investigate potential subgroups of primary care diagnosed patients with polymyalgia rheumatica (PMR) based on self-reported pain and stiffness severity over time.Methods. 652 people with an incident PMR diagnosis were recruited from English general practices and completed a baseline postal questionnaire. They were followed-up with a further six questionnaires over a two-year period. 446 people completed 2-year follow-up. Pain and stiffness were reported on 0-10 numerical rating scales. Latent class growth analysis was used to estimate the joint trajectories of pain and stiffness overtime. A combination ofstatistical and clinical considerations was used to choose the number of clusters. Characteristics of the classes were described. Results. Five clusters were identified. One cluster represented the profile of ‘classical’ PMR symptoms and one represented sustained symptoms that may not be PMR. The other three clusters displayed a partial recovery, a recovery followed by worsening and a slow, but sustained recovery. Those displaying classical PMR symptoms were in better overall health at diagnosis than the other groups.Conclusions. PMR is a heterogeneous condition, with a number of phenotypes. The spectrum of presentation, as well as varying responses to treatment, may be related to underlying health status at diagnosis. Future research should seek to stratify patients at diagnosis to identify those likely to have a poor recovery and in need of an alternative treatment pathway. Clinicians should be aware of the different experiences of patients and monitor symptoms closely, even where there is initial improvement
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