44 research outputs found

    The B7/BB1 antigen provides one of several costimulatory signals for the activation of CD4+ T lymphocytes by human blood dendritic cells in vitro

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    T cells respond to peptide antigen in association with MHC products on antigen-presenting cells (APCs). A number of accessory or costimulatory molecules have been identified that also contribute to T cell activation. Several of the known accessory molecules are expressed by freshly isolated dendritic cells, a distinctive leukocyte that is the most potent APC for the initiation of primary T cell responses. These include ICAM-1 (CD54), LFA-3 (CD58), and class I and II MHC products. Dendritic cells also constitutively express the accessory ligand for CD28, B7/BB1, which has not been previously identified on circulating leukocytes freshly isolated from peripheral blood. Dendritic cell expression of both B7/BB1 and ICAM-1 (CD54) increases after binding to allogeneic T cells. Individual mAbs against several of the respective accessory T cell receptors, e.g., anti-CD2, anti-CD4, anti-CD11a, and anti-CD28, inhibit T cell proliferation in the dendritic cell-stimulated allogeneic mixed leukocyte reaction (MLR) by 40-70%. Combinations of these mAbs are synergistic in achieving near total inhibition. Other T cell-reactive mAbs, e.g., anti-CD5 and anti-CD45, are not inhibitory. Lymphokine secretion and blast transformation are similarly reduced when active accessory ligand-receptor interactions are blocked in the dendritic cell-stimulated allogeneic MLR. Dendritic cells are unusual in their comparably higher expression of accessory ligands, among which B7/BB1 can now be included. These are pertinent to the efficiency with which dendritic cells in small numbers elicit strong primary T cell proliferate and effector responses

    Instability in a non-ohmic/ohmic fluid interface under a perpendicular electric field and unipolar injection

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    We set the equations for the linear electrohydrodynamic instability of an interface between two fluids, subjected to a perpendicular field and a unipolar charge injection. One of the fluids is modeled as being in non-ohmic regime (insulating), whereas the other is ohmic. A new interfacial instability mechanism is described, which may account for the Rose-window instability. The equations are analytically solved in the limit of long wavelength and neglecting the fluid motion. We show that this limit applies well to the case of an air-ohmic liquid interface. The applicability to a liquid-liquid interface is also analyzed

    Examining inequalities in the uptake of the school-based HPV vaccination programme in England: A retrospective cohort study

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    Background: Although uptake of Human Papillomavirus (HPV) vaccine is high in the United Kingdom, it is unknown whether the programme has been delivered equitably by ethnicity or deprivation. This study aimed to investigate factors associated with HPV vaccine initiation and completion within the routine HPV vaccination programme in the South West of England. Methods: Data were retrieved for young women eligible for routine vaccination from 2008/09 to 2010/11 from three Primary Care Trusts (PCTs)/local authorities. Multivariable logistic regression models were developed to examine factors associated with uptake of HPV vaccination. Results: Of 14 282 eligible young women, 12 658 (88.6%) initiated, of whom 11 725 (92.6%) completed the course. Initiation varied by programme year (86.5-89.6%) and PCTs/local authorities (84.8-91.6%). There was strong evidence for an overall difference of initiation by ethnicity (P < 0.001), but not deprivation quintile (P = 0.48). Young women educated in non-mainstream educational settings were less likely to initiate and, if initiated, less likely to complete (both P < 0.001). Conclusions: HPV vaccination uptake did not vary markedly by social deprivation. However, associations with ethnicity and substantially lower uptake in non-mainstream educational settings were observed. Research to identify reasons for low vaccine uptake in these population groups is required. © The Author 2013

    Clinical Course and Quality of Life in High-Risk Patients with Hypertrophic Cardiomyopathy and Implantable Cardioverter-Defibrillators

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    Background: High-risk patients with hypertrophic cardiomyopathy (HCM) are identified by contemporary risk stratification and effectively treated with implantable cardioverter-defibrillators (ICDs). However, long-term HCM clinical course after ICD therapy for ventricular tachyarrhythmias is incompletely understood. Methods and Results: Cohort of 486 high-risk HCM patients with ICDs was assembled from 8 international centers. Clinical course and device interventions were addressed, and survey questionnaires assessed patient anxiety level and psychological well-being related to ICD therapy. Of 486 patients, 94 (19%) experienced appropriate ICD interventions terminating ventricular tachycardia/ventricular fibrillation, 3.7% per year for primary prevention, over 6.4\ub14.7 years. Of 94 patients, 87 were asymptomatic or only mildly symptomatic at the time of appropriate ICD interventions; 74 of these 87 (85%) remained in classes I/II without significant change in clinical status over the subsequent 5.9\ub14.9 years (up to 22). Among the 94 patients, there was one sudden death (caused by device failure; 1.1%); 3 patients died from other HCM-related processes unrelated to arrhythmic risk (eg, end-stage heart failure). Post-ICD intervention, freedom from HCM mortality was 100%, 97%, and 92% at 1, 5, and 10 years, distinctly lower than in ischemic or nonischemic cardiomyopathy ICD trials. HCM patients with ICD interventions reported heightened anxiety in expectation of future shocks, but with intact general psychological well-being and quality of life. Conclusions: In HCM, unlike ischemic heart disease, prevention of sudden death with ICD therapy is unassociated with significant increase in cardiovascular morbidity or mortality, or transformation to heart failure deterioration. ICD therapy does not substantially impair overall psychological and physical well-being
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