58 research outputs found

    Excess Imidacloprid Exposure Causes the Heart Tube Malformation of Chick Embryos

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    As a neonicotinoid pesticide, imidacloprid is widely used to control sucking insects on agricultural planting and fleas on domestic animals. However, the extent to which imidacloprid exposure has an influence on cardiogensis in early embryogenesis is still poorly understood. In vertebrates, the heart is the first organ to be formed. In this study to address whether or not imidacloprid exposure affects early heart development, the early chick embryo has been used as an experimental model because of the accessibility of chick embryo at its early developmental stage. The results demonstrate that exposure of the early chick embryo to imidacloprid caused malformation of heart tube. Furthermorethe data reveal that down-regulation of GATA4, Nkx2.5 and BMP4 and up-regulation of Wnt3a led to aberrant cardiomyocyte differentiation. In addition, imidacloprid exposure interfered with basement membrane (BM) breakdown, E-cadherin/Laminin expression and mesoderm formation during the epithelial-mesenchymal transition (EMT) in gastrula chick embryos. Finally, the DiI-labeled cell migration trajectory indicated that imidacloprid restricted the cell migration of cardiac progenitors to primary heart field in gastrula chick embryos. A similar observation was also obtained from the cell migration assay of scratch wounds in vitro. Additionally, imidacloprid exposure negatively affected the cytoskeleton structure and expression of corresponding adhesion molecules. Taken together, these results reveal that the improper EMT, cardiac progenitor migration and differentiation are responsible for imidacloprid exposure-induced malformation of heart tube during chick embryo development

    Don’t make me angry, you wouldn’t like me when I’m angry: volitional choices to act or inhibit are modulated by subliminal perception of emotional faces

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    Volitional action and self-control—feelings of acting according to one’s own intentions and in being control of one’s own actions—are fundamental aspects of human conscious experience. However, it is unknown whether high-level cognitive control mechanisms are affected by socially salient but nonconscious emotional cues. In this study, we manipulated free choice decisions to act or withhold an action by subliminally presenting emotional faces: In a novel version of the Go/NoGo paradigm, participants made speeded button-press responses to Go targets, withheld responses to NoGo targets, and made spontaneous, free choices to execute or withhold the response for Choice targets. Before each target, we presented emotional faces, backwards masked to render them nonconscious. In Intentional trials, subliminal angry faces made participants more likely to voluntarily withhold the action, whereas fearful and happy faces had no effects. In a second experiment, the faces were made supraliminal, which eliminated the effects of angry faces on volitional choices. A third experiment measured neural correlates of the effects of subliminal angry faces on intentional choice using EEG. After replicating the behavioural results found in Experiment 1, we identified a frontal-midline theta component—associated with cognitive control processes—which is present for volitional decisions, and is modulated by subliminal angry faces. This suggests a mechanism whereby subliminally presented “threat” stimuli affect conscious control processes. In summary, nonconscious perception of angry faces increases choices to inhibit, and subliminal influences on volitional action are deep seated and ecologically embedded

    Cardiovascular development: towards biomedical applicability: Regulation of cardiomyocyte differentiation of embryonic stem cells by extracellular signalling

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    Investigating the signalling pathways that regulate heart development is essential if stem cells are to become an effective source of cardiomyocytes that can be used for studying cardiac physiology and pharmacology and eventually developing cell-based therapies for heart repair. Here, we briefly describe current understanding of heart development in vertebrates and review the signalling pathways thought to be involved in cardiomyogenesis in multiple species. We discuss how this might be applied to stem cells currently thought to have cardiomyogenic potential by considering the factors relevant for each differentiation step from the undifferentiated cell to nascent mesoderm, cardiac progenitors and finally a fully determined cardiomyocyte. We focus particularly on how this is being applied to human embryonic stem cells and provide recent examples from both our own work and that of others

    A strategy to discover new organizers identifies a putative heart organizer

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    Organizers are regions of the embryo that can both induce new fates and impart pattern on other regions. So far, surprisingly few organizers have been discovered, considering the number of patterned tissue types generated during development. This may be because their discovery has relied on transplantation and ablation experiments. Here we describe a new approach, using chick embryos, to discover organizers based on a common gene expression signature, and use it to uncover the anterior intestinal portal (AIP) endoderm as a putative heart organizer. We show that the AIP can induce cardiac identity from non-cardiac mesoderm and that it can pattern this by specifying ventricular and suppressing atrial regional identity. We also uncover some of the signals responsible. The method holds promise as a tool to discover other novel organizers acting during development

    The implications of three major new trials for the effect of water, sanitation and hygiene on childhood diarrhea and stunting: a consensus statement

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    BACKGROUND: Three large new trials of unprecedented scale and cost, which included novel factorial designs, have found no effect of basic water, sanitation and hygiene (WASH) interventions on childhood stunting, and only mixed effects on childhood diarrhea. Arriving at the inception of the United Nations' Sustainable Development Goals, and the bold new target of safely managed water, sanitation and hygiene for all by 2030, these results warrant the attention of researchers, policy-makers and practitioners. MAIN BODY: Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors. We judge these trials to have high internal validity, constituting good evidence that these specific interventions had no effect on childhood linear growth, and mixed effects on childhood diarrhea. These results suggest that, in settings such as these, more comprehensive or ambitious WASH interventions may be needed to achieve a major impact on child health. CONCLUSION: These results are important because such basic interventions are often deployed in low-income rural settings with the expectation of improving child health, although this is rarely the sole justification. Our view is that these three new trials do not show that WASH in general cannot influence child linear growth, but they do demonstrate that these specific interventions had no influence in settings where stunting remains an important public health challenge. We support a call for transformative WASH, in so much as it encapsulates the guiding principle that - in any context - a comprehensive package of WASH interventions is needed that is tailored to address the local exposure landscape and enteric disease burden

    Using social and behavioural science to support COVID-19 pandemic response

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    The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behavior with the recommendations of epidemiologists and public health experts. Here we discuss evidence from a selection of research topics relevant to pandemics, including work on navigating threats, social and cultural influences on behaviour, science communication, moral decision-making, leadership, and stress and coping. In each section, we note the nature and quality of prior research, including uncertainty and unsettled issues. We identify several insights for effective response to the COVID-19 pandemic, and also highlight important gaps researchers should move quickly to fill in the coming weeks and months

    Learning From History About Reducing Infant Mortality: Contrasting the Centrality of Structural Interventions to Early 20th‐Century Successes in the United States to Their Neglect in Current Global Initiatives

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    Do interventions to improve adherence to antiretroviral therapy recognise diversity? A systematic review

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    People living with HIV (PLWH) are often culturally and linguistically diverse populations; these differences are associated with differing barriers to antiretroviral therapy (ART) adherence. Cultural competence measures the extent to which trial design recognises this diversity. This systematic review aimed to determine whether adherence trial participants represent the diversity of PLWH. Randomised Controlled Trials in Organisation for Economic Co-operation and Development countries to improve ART adherence were eligible. We searched MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews. For all included trials, we searched for their development, testing and evaluation studies. We compared trial participant characteristics with nationally reported PLWH data. We appraised trial cultural competence against ten criteria; scoring each criterion as 0, 1 or 2 indicating cultural blindness, pre-competence or competence respectively. For 80 included trials, a further 13 studies presenting development/testing/evaluation data for the included trials were identified. Only one of the 80 included studies reported trial participants representative of the country's population of PLWH. The median (IQ) cultural competence score was 2.5 (1.0, 4.0) out of 20. HIV adherence trial participants are not reflective of the population with HIV, which may be due to limited adoption of culturally competent research methods
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