1,755 research outputs found

    Acute Pressor Response to Psychosocial Stress Is Dependent on Endotheliumā€Derived Endothelinā€1

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    Background Acute psychosocial stress provokes increases in circulating endothelinā€1 (ETā€1) levels in humans and animal models. However, key questions about the physiological function and cellular source of stressā€induced ETā€1 remain unanswered. We hypothesized that endotheliumā€derived ETā€1 contributes to the acute pressor response to stress via activation of the endothelin A receptor. Methods and Results Adult male vascular endotheliumā€specific ETā€1 knockout mice and control mice that were homozygous for the floxed allele were exposed to acute psychosocial stress in the form of cage switch stress (CSS), with blood pressure measured by telemetry. An acute pressor response was elicited by CSS in both genotypes; however, this response was significantly blunted in vascular endotheliumā€specific ETā€1 knockout mice compared with control mice that were homozygous for the floxed allele. In mice pretreated for 3 days with the endothelin A antagonist, ABTā€627, or the dual endothelin A/B receptor antagonist, Aā€182086, the pressor response to CSS was similar between genotypes. CSS significantly increased plasma ETā€1 levels in control mice that were homozygous for the floxed allele. CSS failed to elicit an increase in plasma ETā€1 in vascular endotheliumā€specific ETā€1 knockout mice. Telemetry frequency domain analyses suggested similar autonomic responses to stress between genotypes, and isolated resistance arteries demonstrated similar sensitivity to Ī±1ā€adrenergic receptorā€mediated vasoconstriction. Conclusions These findings specify that acute stressā€induced activation of endotheliumā€derived ETā€1 and subsequent endothelin A receptor activation is a novel mediator of the blood pressure response to acute psychosocial stress

    Human monoclonal antibodies against Ross River virus target epitopes within the E2 protein and protect against disease

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    Ross River fever is a mosquito-transmitted viral disease that is endemic to Australia and the surrounding Pacific Islands. Ross River virus (RRV) belongs to the arthritogenic group of alphaviruses, which largely cause disease characterized by debilitating polyarthritis, rash, and fever. There is no specific treatment or licensed vaccine available, and the mechanisms of protective humoral immunity in humans are poorly understood. Here, we describe naturally occurring human mAbs specific to RRV, isolated from subjects with a prior natural infection. These mAbs potently neutralize RRV infectivity in cell culture and block infection through multiple mechanisms, including prevention of viral attachment, entry, and fusion. Some of the most potently neutralizing mAbs inhibited binding of RRV to Mxra8, a recently discovered alpahvirus receptor. Epitope mapping studies identified the A and B domains of the RRV E2 protein as the major antigenic sites for the human neutralizing antibody response. In experiments in mice, these mAbs were protective against cinical disease and reduced viral burden in multiple tissues, suggesting a potential therapeutic use for humans

    General population screening for type 1 diabetes using islet autoantibodies at the preschool vaccination visit:a proof-of-concept study (the T1Early study)

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    Objective: Type 1 diabetes (T1D) screening programmes testing islet autoantibodies (IAbs) in childhood can reduce life-threatening diabetic ketoacidosis. General population screening is required to detect the majority of children with T1D, since in >85% there is no family history. Age 3ā€“5 years has been proposed as an optimal age for a single screen approach. Design: Capillary samples were collected from children attending their preschool vaccination and analysed for IAbs to insulin, glutamic acid decarboxylase, islet antigen-2 and zinc transporter 8 using radiobinding/luciferase immunoprecipitation system assays. Acceptability was assessed using semistructured interviews and open-ended postcard questionnaires with parents. Setting: Two primary care practices in Oxfordshire, UK. Main outcome measures: The ability to collect capillary blood to test IAbs in children at the routine preschool vaccination (3.5ā€“4 years). Results: Of 134 parents invited, 66 (49%) were recruited (median age 3.5 years (IQR 3.4ā€“3.6), 26 (39.4%) male); 63 provided a sample (97% successfully), and one participant was identified with a single positive IAb. Parents (n=15 interviews, n=29 postcards) were uniformly positive about screening aligned to vaccination and stated they would have been less likely to take part had screening been a separate visit. Themes identified included preparedness for T1D and the long-term benefit outweighing short-term upset. The perceived volume of the capillary sample was a potential concern and needs optimising. Conclusions: Capillary IAb testing is a possible method to screen children for T1D. Aligning collection to the preschool vaccination visit can be convenient for families without the need for an additional visit

    General population screening for type 1 diabetes using islet autoantibodies at the preschool vaccination visit: a proof-of-concept study (the T1Early study)

    Get PDF
    Objective: Type 1 diabetes (T1D) screening programmes testing islet autoantibodies (IAbs) in childhood can reduce life-threatening diabetic ketoacidosis. General population screening is required to detect the majority of children with T1D, since in >85% there is no family history. Age 3ā€“5 years has been proposed as an optimal age for a single screen approach. Design: Capillary samples were collected from children attending their preschool vaccination and analysed for IAbs to insulin, glutamic acid decarboxylase, islet antigen-2 and zinc transporter 8 using radiobinding/luciferase immunoprecipitation system assays. Acceptability was assessed using semistructured interviews and open-ended postcard questionnaires with parents. Setting: Two primary care practices in Oxfordshire, UK. Main outcome measures: The ability to collect capillary blood to test IAbs in children at the routine preschool vaccination (3.5ā€“4 years). Results: Of 134 parents invited, 66 (49%) were recruited (median age 3.5 years (IQR 3.4ā€“3.6), 26 (39.4%) male); 63 provided a sample (97% successfully), and one participant was identified with a single positive IAb. Parents (n=15 interviews, n=29 postcards) were uniformly positive about screening aligned to vaccination and stated they would have been less likely to take part had screening been a separate visit. Themes identified included preparedness for T1D and the long-term benefit outweighing short-term upset. The perceived volume of the capillary sample was a potential concern and needs optimising. Conclusions: Capillary IAb testing is a possible method to screen children for T1D. Aligning collection to the preschool vaccination visit can be convenient for families without the need for an additional visit

    General population screening for type 1 diabetes using islet autoantibodies at the preschool vaccination visit:a proof-of-concept study (the T1Early study)

    Get PDF
    Objective: Type 1 diabetes (T1D) screening programmes testing islet autoantibodies (IAbs) in childhood can reduce life-threatening diabetic ketoacidosis. General population screening is required to detect the majority of children with T1D, since in >85% there is no family history. Age 3ā€“5 years has been proposed as an optimal age for a single screen approach. Design: Capillary samples were collected from children attending their preschool vaccination and analysed for IAbs to insulin, glutamic acid decarboxylase, islet antigen-2 and zinc transporter 8 using radiobinding/luciferase immunoprecipitation system assays. Acceptability was assessed using semistructured interviews and open-ended postcard questionnaires with parents. Setting: Two primary care practices in Oxfordshire, UK. Main outcome measures: The ability to collect capillary blood to test IAbs in children at the routine preschool vaccination (3.5ā€“4 years). Results: Of 134 parents invited, 66 (49%) were recruited (median age 3.5 years (IQR 3.4ā€“3.6), 26 (39.4%) male); 63 provided a sample (97% successfully), and one participant was identified with a single positive IAb. Parents (n=15 interviews, n=29 postcards) were uniformly positive about screening aligned to vaccination and stated they would have been less likely to take part had screening been a separate visit. Themes identified included preparedness for T1D and the long-term benefit outweighing short-term upset. The perceived volume of the capillary sample was a potential concern and needs optimising. Conclusions: Capillary IAb testing is a possible method to screen children for T1D. Aligning collection to the preschool vaccination visit can be convenient for families without the need for an additional visit

    Si IV COLUMN DENSITIES PREDICTED FROM NON-EQUILIBRIUM IONIZATION SIMULATIONS OF TURBULENT MIXING LAYERS AND HIGH-VELOCITY CLOUDS

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    We present predictions of the Si IV ions in turbulent mixing layers (TMLs) between hot and cool gas and in cool high-velocity clouds (HVCs) that travel through a hot halo, complementing the C IV, N V, and O VI predictions in Kwak & Shelton, Kwak et al., and Henley et al. We find that the Si IV ions are most abundant in regions where the hot and cool gases first begin to mix or where the mixed gas has cooled significantly. The predicted column densities of high velocity Si IV and the predicted ratios of Si IV to C IV and O VI found on individual sightlines in our HVC simulations are in good agreement with observations of high velocity gas. Low velocity Si IV is also seen in the simulations, as a result of decelerated gas in the case of the HVC simulations and when looking along directions that pass perpendicular to the direction of motion in the TML simulations. The ratios of low velocity Si IV to C IV and O VI in the TML simulations are in good agreement with those recorded for Milky Way halo gas, while the ratio of Si IV to O VI from the decelerated gas in the HVC simulations is lower than that observed at normal velocity in the Milky Way halo. We attribute the shortfall of normal velocity Si IV to not having modeled the effects of photoionization and, following Henley et al., consider a composite model that includes decelerated HVC gas, supernova remnants, galactic fountain gas, and the effect of photoionizationopen

    Electronically delivered, multicomponent intervention to reduce unnecessary antibiotic prescribing for respiratory infections in primary care: a cluster randomised trial using electronic health recordsā€”REDUCE Trial study original protocol

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    Introduction Respiratory tract infections (RTIs) account for about 60% of antibiotics prescribed in primary care. This study aims to test the effectiveness, in a cluster randomised controlled trial, of electronically delivered, multicomponent interventions to reduce unnecessary antibiotic prescribing when patients consult for RTIs in primary care. The research will specifically evaluate the effectiveness of feeding back electronic health records (EHRs) data to general practices. Methods and analysis 2-arm cluster randomised trial using the EHRs of the Clinical Practice Research Datalink (CPRD). General practices in England, Scotland, Wales and Northern Ireland are being recruited and the general population of all ages represents the target population. Control trial arm practices will continue with usual care. Practices in the intervention arm will receive complex multicomponent interventions, delivered remotely to information systems, including (1) feedback of each practice's antibiotic prescribing through monthly antibiotic prescribing reports estimated from CPRD data; (2) delivery of educational and decision support tools; (3) a webinar to explain and promote effective usage of the intervention. The intervention will continue for 12?months. Outcomes will be evaluated from CPRD EHRs. The primary outcome will be the number of antibiotic prescriptions for RTIs per 1000 patient years. Secondary outcomes will be: the RTI consultation rate; the proportion of consultations for RTI with an antibiotic prescribed; subgroups of age; different categories of RTI and quartiles of intervention usage. There will be more than 80% power to detect an absolute reduction in antibiotic prescription for RTI of 12 per 1000 registered patient years. Total healthcare usage will be estimated from CPRD data and compared between trial arms. Ethics and dissemination Trial protocol was approved by the National Research Ethics Service Committee (14/LO/1730). The pragmatic design of the trial will enable subsequent translation of effective interventions at scale in order to achieve population impact. <br/
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