799 research outputs found

    Clathrin heavy chain 22 contributes to the control of neuropeptide degradation and secretion during neuronal development.

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    The repertoire of cell types in the human nervous system arises through a highly orchestrated process, the complexity of which is still being discovered. Here, we present evidence that CHC22 has a non-redundant role in an early stage of neural precursor differentiation, providing a potential explanation of why CHC22 deficient patients are unable to feel touch or pain. We show the CHC22 effect on neural differentiation is independent of the more common clathrin heavy chain CHC17, and that CHC22-dependent differentiation is mediated through an autocrine/paracrine mechanism. Using quantitative proteomics, we define the composition of clathrin-coated vesicles in SH-SY5Y cells, and determine proteome changes induced by CHC22 depletion. In the absence of CHC22 a subset of dense core granule (DCG) neuropeptides accumulated, were processed into biologically active 'mature' forms, and secreted in sufficient quantity to trigger neural differentiation. When CHC22 is present, however, these DCG neuropeptides are directed to the lysosome and degraded, thus preventing differentiation. This suggests that the brief reduction seen in CHC22 expression in sensory neural precursors may license a step in neuron precursor neurodevelopment; and that this step is mediated through control of a novel neuropeptide processing pathway

    AP-4 vesicles contribute to spatial control of autophagy via RUSC-dependent peripheral delivery of ATG9A.

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    Adaptor protein 4 (AP-4) is an ancient membrane trafficking complex, whose function has largely remained elusive. In humans, AP-4 deficiency causes a severe neurological disorder of unknown aetiology. We apply unbiased proteomic methods, including 'Dynamic Organellar Maps', to find proteins whose subcellular localisation depends on AP-4. We identify three transmembrane cargo proteins, ATG9A, SERINC1 and SERINC3, and two AP-4 accessory proteins, RUSC1 and RUSC2. We demonstrate that AP-4 deficiency causes missorting of ATG9A in diverse cell types, including patient-derived cells, as well as dysregulation of autophagy. RUSC2 facilitates the transport of AP-4-derived, ATG9A-positive vesicles from the trans-Golgi network to the cell periphery. These vesicles cluster in close association with autophagosomes, suggesting they are the "ATG9A reservoir" required for autophagosome biogenesis. Our study uncovers ATG9A trafficking as a ubiquitous function of the AP-4 pathway. Furthermore, it provides a potential molecular pathomechanism of AP-4 deficiency, through dysregulated spatial control of autophagy

    Slow progressors to type 1 diabetes lose islet autoantibodies over time, have few islet antigen-specific CD8+ T cells and exhibit a distinct CD95hi B cell phenotype

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    ims/hypothesis The aim of this study was to characterise islet autoantibody profiles and immune cell phenotypes in slow progressors to type 1 diabetes. Methods Immunological variables were compared across peripheral blood samples obtained from slow progressors to type 1 diabetes, individuals with newly diagnosed or long-standing type 1 diabetes, and healthy individuals. Polychromatic flow cytometry was used to characterise the phenotypic attributes of B and T cells. Islet autoantigen-specific B cells were quantified using an enzyme-linked immunospot (ELISpot) assay and islet autoantigen-specific CD8+ T cells were quantified using peptide–HLA class I tetramers. Radioimmunoassays were used to detect islet autoantibodies. Sera were assayed for various chemokines, cytokines and soluble receptors via ELISAs. Results Islet autoantibodies were lost over time in slow progressors. Various B cell subsets expressed higher levels of CD95 in slow progressors, especially after polyclonal stimulation, compared with the corresponding B cell subsets in healthy donors (p < 0.05). The phenotypic characteristics of CD4+ and CD8+ T cells were similar in slow progressors and healthy donors. Lower frequencies of CD4+ T cells with a central memory phenotype (CD27int, CD127+, CD95int) were observed in slow progressors compared with healthy donors (mean percentage of total CD4+ T cells was 3.00% in slow progressors vs 4.67% in healthy donors, p < 0.05). Autoreactive B cell responses to proinsulin were detected at higher frequencies in slow progressors compared with healthy donors (median no. of spots was 0 in healthy donors vs 24.34 in slow progressors, p < 0.05) in an ELISpot assay. Islet autoantigen-specific CD8+ T cell responses were largely absent in slow progressors and healthy donors. Serum levels of DcR3, the decoy receptor for CD95L, were elevated in slow progressors compared with healthy donors (median was 1087 pg/ml in slow progressors vs 651 pg/ml in healthy donors, p = 0.06). Conclusions/interpretation In this study, we found that slow progression to type 1 diabetes was associated with a loss of islet autoantibodies and a distinct B cell phenotype, consistent with enhanced apoptotic regulation of peripheral autoreactivity via CD95. These phenotypic changes warrant further studies in larger cohorts to determine their functional implications

    LGBTQI inclusive cancer care : a discourse analytic study of health care professional, patient and carer perspectives

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    Background: Awareness of the specific needs of LGBTQI cancer patients has led to calls for inclusivity, cultural competence, cultural safety and cultural humility in cancer care. Examination of oncology healthcare professionals’ (HCP) perspectives is central to identifying barriers and facilitators to inclusive LGBTQI cancer care. Study Aim: This study examined oncology HCPs perspectives in relation to LGBTQI cancer care, and the implications of HCP perspectives and practices for LGBTQI patients and their caregivers. Method: 357 oncology HCPs in nursing (40%), medical (24%), allied health (19%) and leadership (11%) positions took part in a survey; 48 HCPs completed an interview. 430 LGBTQI patients, representing a range of tumor types, sexual and gender identities, age and intersex status, and 132 carers completed a survey, and 104 LGBTQI patients and 31 carers undertook an interview. Data were analysed using thematic discourse analysis. Results: Three HCP subject positions – ways of thinking and behaving in relation to the self and LGBTQI patients – were identified:’Inclusive and reflective’ practitioners characterized LGBTQI patients as potentially vulnerable and offered inclusive care, drawing on an affirmative construction of LGBTQI health. This resulted in LGBTQI patients and their carers feeling safe and respected, willing to disclose sexual orientation and gender identity (SOGI) status, and satisfied with cancer care. ‘Egalitarian practitioners’ drew on discourses of ethical responsibility, positioning themselves as treating all patients the same, not seeing the relevance of SOGI information. This was associated with absence of LGBTQI-specific information, patient and carer anxiety about disclosure of SOGI, feelings of invisibility, and dissatisfaction with healthcare. ‘Anti-inclusive’ practitioners’ expressed open hostility and prejudice towards LGBTQI patients, reflecting a cultural discourse of homophobia and transphobia. This was associated with patient and carer distress, feelings of negative judgement, and exclusion of same-gender partners. Conclusion: Derogatory views and descriptions of LGBTQI patients, and cis-normative practices need to be challenged, to ensure that HCPs offer inclusive and affirmative care. Building HCP’s communicative competence to work with LGBTQI patients needs to become an essential part of basic training and ongoing professional development. Visible indicators of LGBTQI inclusivity are essential, alongside targeted resources and information for LGBTQI people

    Developmental change in look durations predicts later effortful control in toddlers at familial risk for ASD

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    Background: Difficulties with Executive Functioning (EF) are common in individuals with a range of developmental disorders, including Autism Spectrum Disorder (ASD). Interventions that target underlying mechanisms of EF early in development could be broadly beneficial, but require infant markers of such mechanisms in order to be feasible. Prospective studies of infants at high familial risk (HR) for ASD have revealed a surprising tendency for HR toddlers to show longer epochs of attention to faces than low-risk (LR) controls. In typical development, decreases in look durations towards the end of the first year of life are driven by the development of executive attention – a foundational component of EF. Here, we test the hypothesis that prolonged attention to visual stimuli (including faces) in HR toddlers reflects early differences in the development of executive attention. Methods: In a longitudinal prospective study, we used eye-tracking to record HR and LR infants’ looking behaviour to social and non-social visual stimuli at ages 9 and 15 months. At age 3 years we assessed children with a battery of clinical research measures and collected parental report of Effortful Control (EC) – a temperament trait closely associated with EF and similarly contingent on executive attention. Results: Consistent with previous studies, we found an attenuated reduction in peak look durations to faces between 9 and 15 months for the HR group compared with the LR group, and lower EC amongst the HR-ASD group. In line with our hypothesis, change in peak look duration to faces between 9 and 15 months was negatively associated with EC at age 3. Conclusions: We suggest that for HR toddlers, disruption to the early development of executive attention results in an attenuated reduction in looking time to faces. Effects may be more apparent for faces due to early biases to orient towards them; further, attention difficulties may interact with earlier-emerging differences in social information processing. Our finding that prolonged attention to faces may be an early indicator of disruption to the executive attention system is of potential value in screening for infants at risk for later EF difficulties and for evaluation of intervention outcomes

    Impact of newborn screening for SCID on the management of congenital athymia

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    BACKGROUND: Newborn screening (NBS) programmes for severe combined immunodeficiency (SCID) facilitate early SCID diagnosis and promote early treatment with haematopoietic stem cell transplantation, resulting in improved clinical outcomes. Infants with congenital athymia are also identified through NBS due to severe T-cell lymphopaenia. With the expanding introduction of NBS programmes, referrals of athymic patients for treatment with thymus transplantation have recently increased at Great Ormond Street Hospital (GOSH), London, United Kingdom. OBJECTIVE: We studied the impact of NBS on timely diagnosis and treatment of athymic infants with thymus transplantation at GOSH. METHODS: We compared the age at referral and complications between athymic infants diagnosed after clinical presentation (N=25) and patients identified through NBS (N=19), referred for thymus transplantation at GOSH between 10/2019 and 02/2023. We assessed whether age at time of treatment influences thymic output at 6 and 12 months after transplantation. RESULTS: Infants referred after NBS identification were significantly younger and had less complications, in particular less infections. All deaths occurred in the non-NBS group, including six patients before and two after thymus transplantation because of pre-existing infections. In the absence of significant co-morbidities or diagnostic uncertainties, timely treatment was more frequently achieved after NBS. Treatment at <4 months of age was associated with higher thymic output at 6- and 12-months post-transplantation. CONCLUSION: NBS contributes to earlier recognition of congenital athymia, promoting referral of athymic patients for thymus transplantation prior to acquiring infections or other complications, and facilitating treatment at younger age, thus playing an important role in improving their outcomes

    Impact of newborn screening for SCID on the management of congenital athymia

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    Background Newborn screening (NBS) programs for severe combined immunodeficiency facilitate early diagnosis of severe combined immunodeficiency and promote early treatment with hematopoietic stem cell transplantation, resulting in improved clinical outcomes. Infants with congenital athymia are also identified through NBS because of severe T-cell lymphopenia. With the expanding introduction of NBS programs, referrals of athymic patients for treatment with thymus transplantation have recently increased at Great Ormond Street Hospital (GOSH) (London, United Kingdom). Objective We studied the impact of NBS on timely diagnosis and treatment of athymic infants with thymus transplantation at GOSH. Methods We compared age at referral and complications between athymic infants diagnosed after clinical presentation (n = 25) and infants identified through NBS (n = 19) who were referred for thymus transplantation at GOSH between October 2019 and February 2023. We assessed whether age at time of treatment influences thymic output at 6 and 12 months after transplantation. Results The infants referred after identification through NBS were significantly younger and had fewer complications, in particular fewer infections. All deaths occurred in the group of those who did not undergo NBS, including 6 patients before and 2 after thymus transplantation because of preexisting infections. In the absence of significant comorbidities or diagnostic uncertainties, timely treatment was achieved more frequently after NBS. Treatment when younger than age 4 months was associated with higher thymic output at 6 and 12 months after transplantation. Conclusion NBS contributes to earlier recognition of congenital athymia, promoting referral of athymic patients for thymus transplantation before they acquire infections or other complications and facilitating treatment at a younger age, thus playing an important role in improving their outcomes

    The role of the smartphone in the transition from medical student to foundation trainee: a qualitative interview and focus group study

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    Background The transition from medical student to junior doctor is one of the most challenging in medicine, affecting both doctor and patient health. Opportunities to support this transition have arisen from advances in mobile technology and increased smartphone ownership. Methods This qualitative study consisted of six in-depth interviews and two focus groups with Foundation Year 1 Trainees (intern doctors) and final year medical students within the same NHS Trust. A convenience sample of 14 participants was recruited using chain sampling. Interviews and focus groups were recorded, transcribed verbatim, analysed in accordance with thematic analysis and presented below in keeping with the standards for reporting qualitative research. Results Participants represented both high and low intensity users. They used their smartphones to support their prescribing practices, especially antimicrobials through the MicroGuideâ„¢ app. Instant messaging, via WhatsApp, contributed to the existing bleep system, allowing coordination of both work and learning opportunities across place and time. Clinical photographs were recognised as being against regulations but there had still been occasions of use despite this. Concerns about public and colleague perceptions were important to both students and doctors, with participants describing various tactics employed to successfully integrate phone use into their practices. Conclusion This study suggests that both final year medical students and foundation trainees use smartphones in everyday practice. Medical schools and healthcare institutions should seek to integrate such use into core curricula/training to enable safe and effective use and further ease the transition to foundation training. We recommend juniors are reminded of the potential risks to patient confidentiality associated with smartphone use

    Exploring the Darkverse:A Multi-Perspective Analysis of the Negative Societal Impacts of the Metaverse

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    The Metaverse has the potential to form the next pervasive computing archetype that can transform many aspects of work and life at a societal level. Despite the many forecasted benefits from the metaverse, its negative outcomes have remained relatively unexplored with the majority of views grounded on logical thoughts derived from prior data points linked with similar technologies, somewhat lacking academic and expert perspective. This study responds to the dark side perspectives through informed and multifaceted narratives provided by invited leading academics and experts from diverse disciplinary backgrounds. The metaverse dark side perspectives covered include: technological and consumer vulnerability, privacy, and diminished reality, human–computer interface, identity theft, invasive advertising, misinformation, propaganda, phishing, financial crimes, terrorist activities, abuse, pornography, social inclusion, mental health, sexual harassment and metaverse-triggered unintended consequences. The paper concludes with a synthesis of common themes, formulating propositions, and presenting implications for practice and policy.</p
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