104 research outputs found

    NODAL/TGFβ signalling mediates the self-sustained stemness induced by PIK3CAH1047R homozygosity in pluripotent stem cells

    Get PDF
    Activating PIK3CA mutations are known “drivers” of human cancer and developmental overgrowth syndromes. We recently demonstrated that the "hotspot" PIK3CAH1047R variant exerts unexpected allele dose-dependent effects on stemness in human pluripotent stem cells (hPSCs). In the present study, we combine high-depth transcriptomics, total proteomics and reverse-phase protein arrays to reveal potentially disease-related alterations in heterozygous cells, and to assess the contribution of activated TGFβ signalling to the stemness phenotype of homozygous PIK3CAH1047R cells. We demonstrate signalling rewiring as a function of oncogenic PI3K signalling strength, and provide experimental evidence that self-sustained stemness is causally related to enhanced autocrine NODAL/TGFβ signalling. A significant transcriptomic signature of TGFβ pathway activation in heterozygous PIK3CAH1047R was observed but was modest and was not associated with the stemness phenotype seen in homozygous mutants. Notably, the stemness gene expression in homozygous PIK3CAH1047R iPSCs was reversed by pharmacological inhibition of NODAL/TGFβ signalling, but not by pharmacological PI3Kα pathway inhibition. Altogether, this provides the first in-depth analysis of PI3K signalling in human pluripotent stem cells and directly links strong PI3K activation to developmental NODAL/TGFβ signalling. This work illustrates the importance of allele dosage and expression when artificial systems are used to model human genetic disease caused by activating PIK3CA mutations

    Evaluation of the Victorian Healthy Homes Program: protocol for a randomised controlled trial.

    Full text link
    INTRODUCTION: The evaluation of the Victorian Healthy Homes Program (VHHP) will generate evidence about the efficacy and cost-effectiveness of home upgrades to improve thermal comfort, reduce energy use and produce health and economic benefits to vulnerable households in Victoria, Australia. METHODS AND ANALYSIS: The VHHP evaluation will use a staggered, parallel group clustered randomised controlled trial to test the home energy intervention in 1000 households. All households will receive the intervention either before (intervention group) or after (control group) winter (defined as 22 June to 21 September). The trial spans three winters with differing numbers of households in each cohort. The primary outcome is the mean difference in indoor average daily temperature between intervention and control households during the winter period. Secondary outcomes include household energy consumption and residential energy efficiency, self-reported respiratory symptoms, health-related quality of life, healthcare utilisation, absences from school/work and self-reported conditions within the home. Linear and logistic regression will be used to analyse the primary and secondary outcomes, controlling for clustering of households by area and the possible confounders of year and timing of intervention, to compare the treatment and control groups over the winter period. Economic evaluation will include a cost-effectiveness and cost-benefit analysis. ETHICS AND DISSEMINATION: Ethical approval was received from Victorian Department of Human Services Human Research Ethics Committee (reference number: 04/17), University of Technology Sydney Human Research Ethics Committee (reference number: ETH18-2273) and Australian Government Department of Veterans Affairs. Study results will be disseminated in a final report and peer-reviewed journals. TRIAL REGISTRATION NUMBER: ACTRN12618000160235

    Biogeochemical signatures in the lichen Hypogymnia physodes in the mid Urals

    Get PDF
    Abstract Multi-element content and uranium (U) isotopes were investigated in the lichen Hypogymnia physodes (native and transplants) sampled across a 60-km transect, centred on Karabash smelter town, from Turgoyak Lake (SW) to Kyshtym (NE) to investigate the origin of U. Kyshtym was the site of a major nuclear accident in 1957. 234 U/ 238 U activity ratios in native thalli sampled during July 2001 were within the natural isotopic ratio in minerals. Uranium/thorium (U/Th) ratios were higher in native thalli towards the NE (average 0.73) than those in the SW (average 0.57). Element signatures in native thalli and transplants suggest U was derived from fossil fuel combustion from Karabash and sources lying further to the east. Systematic and significant U enrichment indicative of a nuclear fuel cycle source was not detected in any sample. Element signatures in epiphytic lichen transplants and native thalli provide a powerful method to evaluate U deposition

    The Importance of Social Support Structures for Retention and Success

    Get PDF
    As a policy goal, widening participation is increasingly associated with retention and completion. For those who are concerned with equity or social mobility, it makes little sense to recruit new types of student if they do not then qualify for a graduate profession. There has been growing interest in retention and completion among researchers and policymakers, with much attention centring on the extent to which new students can be helped to integrate into the institution. Drawing on a study of undergraduates in the UK, this chapter explores the extent to which student support services and wider informal support networks feature in students' narratives of retention. Conceptually, we are interested here in the ways in which students feel themselves to be legitimate members of the ‘imagined community' of higher education, a concept that we have adapted from Anderson's treatment of nationalisms (Anderson, 1991)

    Positive and negative effects of antipsychotic medication: an international online survey of 832 recipients

    Get PDF
    Background: Antipsychotic medication is currently the treatment of choice for psychosis, but few studies directly survey the first hand experience of recipients. Objectives: To ascertain the experiences and opinions of users of an international sample of antipsychotic drugs regarding positive and negative effects. Method: An online direct-to-consumer questionnaire was completed by 832 users of antipsychotics, from 30 countries – predominantly USA, UK and Australia. This is the largest such sample to date. Results: Over half (56%) thought the drugs reduced the problems they were prescribed for, but 27% thought they made them worse. Slightly less people found the drugs generally ‘Helpful’ (41%) than found them ‘Unhelpful’ (43%). While 35% reported that their ‘quality of life’ was ‘improved’, 54% reported that it was made ‘worse’. The average number of adverse effects reported was 11, with an average of five at the ‘severe’ level. Fourteen effects were reported by 57% or more participants, most commonly: ‘Drowsiness, feeling tired, sedation’ (92%), ‘Loss of motivation’ (86%), ‘Slowed thoughts’ (86%), and ‘Emotional numbing’ (85%). Suicidality was reported to be a side effect by 58%. Older people reported particularly poor outcomes and high levels of adverse effects. Duration of treatment was unrelated to positive outcomes but significantly related to negative outcomes. Most respondents (70%) had tried to stop taking the drugs. The most common reasons people wanted to stop were the side effects (64%) and worries about long-term physical health (52%). Most (70%) did not recall being told anything at all about side effects. Conclusions Clinical implications are discussed, with a particular focus on the principles of informed consent, and involving patients in decision making about their own lives

    A fast and flexible panoramic virtual reality system for behavioural and electrophysiological experiments

    Get PDF
    Ideally, neuronal functions would be studied by performing experiments with unconstrained animals whilst they behave in their natural environment. Although this is not feasible currently for most animal models, one can mimic the natural environment in the laboratory by using a virtual reality (VR) environment. Here we present a novel VR system based upon a spherical projection of computer generated images using a modified commercial data projector with an add-on fish-eye lens. This system provides equidistant visual stimulation with extensive coverage of the visual field, high spatio-temporal resolution and flexible stimulus generation using a standard computer. It also includes a track-ball system for closed-loop behavioural experiments with walking animals. We present a detailed description of the system and characterize it thoroughly. Finally, we demonstrate the VR system’s performance whilst operating in closed-loop conditions by showing the movement trajectories of the cockroaches during exploratory behaviour in a VR forest
    corecore