1,721,038 research outputs found

    Susceptibility to HIV infection and AIDS in Italian haemophiliacs is HLA associated

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    We compared the frequencies of HLA antigens in two matched groups of 31 HIV-seronegative and 31 HIV-seropositive haemophiliacs, exposed during the years 1981-85 to comparable amounts and batches of presumably infectious clotting factor concentrates. The frequency of A2 was significantly higher in HIV-seropositive than in seronegative haemophiliacs, with a relative risk (RR) of seroconversion of 3.92, whereas both Bw52 and DR4 were negatively associated with it. We also studied the distribution of HLA antigens in a larger group of 76 HIV-seropositive haemophiliacs, who were at different clinical stages of HIV infection (CDC classes II-IV) but were comparable for age and time elapsed since seroconversion. DR3 and DQw2 antigens were, particularly when concomitantly present, associated with a high risk of developing symptomatic HIV infection (RR = 11.79 and 25.33). Our data suggest that the HLA region controls susceptibility to infection with HIV and its progression to symptomatic disease in Italian haemophiliac

    Novel mode of action of iloprost: in vitro down-regulation of endothelial cell adhesion molecules

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    Iloprost is a stable prostacyclin analog commonly employed in the treatment of peripheral vascular disease and also indicated in the treatment of patients affected by systemic sclerosis (SSc) in the presence of severe Raynaud's phenomenon (RP). Several mechanisms of action of the drug other than vasodilation and antiplatelet effect have been demonstrated that may be involved in the exertion of its clinical efficacy. Aim of the present study was to investigate whether iloprost down-regulated lymphocyte adhesion to endothelium through a modulation of adhesion molecule expression on the surface of endothelial cells. In the presence of iloprost, both lymphocyte adhesion and IL-1 stimulated expression of ICAM-1 and ELAM-1 exhibited a significant reduction, while unstimulated adhesion molecule expression was not significantly affected. Our results confirm that iloprost is able to down-regulate lymphocyte adhesion to endothelial cells and indicate that endothelium itself could be target of iloprost administration. Attenuation of the inflammatory response through modulation of cellular interactions could be suggested as a potential mechanism of action of iloprost, when used in the treatment of pathological conditions characterized by endothelial activation

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Serum factors influencing spontaneous rosette formation by lymphocytes of pregnant women

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    The effect of sera from pregnant women on the percentage of spontaneous rosette-forming peripheral lymphocytes was investigated. Pregnancy lymphocytes displayed a significantly lower capacity to bind SRBC than control male lymphocytes. However, after an exhaustive washing, it was possible to demonstrate a significant increase of spontaneous rosettes formed by pregnancy lymphocytes. It was found that the incubation of pregnancy-washed lymphocytes with pregnancy but not homologous male serum restored to depressed levels the values of rosette-forming peripheral lymphocytes. This blocking activity was significantly higher with autologous serum than homologous pregnancy serum. Control lymphocytes were unaffected both by washing and by incubation with pregnancy sera. The blocking activity was found in the same ion-exchange chromatography fraction of pregnancy serum where paternal HLA antigens could be demonstrated, and was reproduced by a soluble HLA preparation from the husband's lymphocytes

    Induction of CD69 activation molecule on human neutrophils by GM-CSF, IFN-γ, and IFN-α

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    The CD69 glycoprotein is an early activation antigen of T and B lymphocytes but it expression is induced in vitro on cells of most hematopoietic lineages, including neutrophils after stimulation with PMA or fMLP. In this study, we investigated whether CD69 expression on human neutrophils could be modulated by inflammatory or anti-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, G-CSF, GM-CSF, TNF-α, TGF-β, IFN-α, IFN-γ). Resting neutrophils from healthy subjects did not express CD69 on the cell surface; moreover, a preformed intracellular pool of CD69 was not evident in these cells. CD69 was barely detectable on these cells after overnight incubation in medium while overnight incubation with GM-CSF, IFN-γ or IFN-α significantly induced CD69 expression on neutrophils with GM-CSF appearing to be the most potent inducer. This induction was dependent on a new protein synthesis as it was significantly inhibited by cycloheximide (about 50% inhibition). CD69 cross-linking on GM-CSF-primed neutrophils sinergized with LPS and increased TNF-α production and secretion suggesting a role for CD69-positive neutrophils in the pathogenesis and maintenance of different inflammatory diseases
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