1,721,019 research outputs found
Fisiopatologia della risposta immunitaria nel compartimento liquorale. XXXVII Congress of the Italian Neurological Society, Bari 14-18 October 2006.
No full textEpstein-Barr virus and multiple sclerosis.
Full text linkPURPOSE OF REVIEW: Recent studies have revived interest in the long-scrutinized association between Epstein-Barr virus (EBV) and multiple sclerosis (MS). We review this evidence and discuss it in relation to MS pathological and clinical features and patients' response to immunosuppressive therapies. RECENT FINDINGS: Serological evidence of previous exposure to EBV in children with MS supports a role for EBV infection early in MS pathogenesis, as already indicated by prospective studies in adults. Higher antibody titers and T-cell responses to EBV in patients compared to healthy EBV carriers indicate possible continuous viral reactivation, whereas there is some evidence that EBV could break immune tolerance to myelin antigens through molecular mimicry. Detection of EBV-infected B-cells in patients' brain raises the possibility that intrathecal B-cell abnormalities and T-cell-mediated immunopathology in MS are the consequence of a persistently dysregulated EBV infection. Accordingly, targeting T-cells and/or B-cells with monoclonal antibody therapies ameliorates MS. Whether EBV has a causative or pathogenic role in MS can now be addressed in relation to genetic, hormonal and other environmental influences that may affect EBV-host interactions. SUMMARY: By shedding light on the involvement of EBV in MS, these findings will pave the way to disease prevention and increase the therapeutic index of future treatments
Angiotensin II modulates the activity of Na+/K+ATPase in cultured rat astrocytes via the AT1 receptor and protein kinase C-delta activation
No full textIn astrocytes the activity of the Na+,K+-ATPase pump maintains an inwardly directed electrochemical sodium gradient used by the Na+-dependent transporters and regulates the extracellular K+ concentration essential for neuronal excitability, We show here that incubation of cultured rat astrocytes with angiotensin II (Ang II) modulates Na+,K+-ATPase activity, in a dose-and time-dependent manner. Na+,K+-ATPase activation was mediated by binding of Ang II to AT1 receptors as it was completely blocked by DuP 753, a specific AT1 receptor subtype antagonist, Stimulation of Na+,K+-ATPase activity by Ang II was dependent on protein kinase C (PKC) activation because PKC antagonists abolished the inducing effect of Ang II and the PKC activator phorbol 12-myristate 13-acetate enhanced transporter activity, Ang II stimulated translocation of PKC-delta but not that of other PKC isoforms from the cytosol to the plasma membrane. These results indicate that the activity of Na+,K+-ATPase in astrocytes is increased by physiological concentrations of Ang II and that the AT1 receptor subtype mediates the Na+,K+-ATPase response to Ang II via PKC-delta activation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
The costimulatory molecule B7 is expressed on human microglia in culture and in multiple sclerosis acute lesions.
No full textB7 is a costimulatory molecule which is expressed on antigen-presenting cells and which plays a pivotal role in T cell activation and proliferation. To elucidate mechanisms regulating intracerebral immune responses, expression of B7 was examined in cultured microglial cells and in brain tissue from control and multiple sclerosis patients. Using immunocytochemical and polymerase chain reaction techniques, we show that B7 was expressed in cultured microglial cells from the human embryonic brain. Microglia also bound the soluble form of the B7 receptor CTLA-4 (CTLA-4-Ig). B7 gene expression and binding of anti-B7 antibodies and CTLA-4-Ig increased after treatment with interferon-gamma B7 was not inducible in human astrocytes. Human microglia expressed other costimulatory molecules, such as intercellular adhesion molecule-1, LFA-I and LFA-3. In sections of multiple sclerosis brains, B7 immunoreactivity was detected on activated microglia and infiltrating macrophages within active lesions. In chronic lesions, only perivascular cells were stained. B7 immunoreactivity was undetectable in sections from Alzheimer's disease or normal brain tissue. These data suggest that B7 may be involved in T cell activation and lesion development in multiple sclerosis and that the regulated expression of B7 on microglia may contribute to the local stimulation of T cell proliferation and effector functions
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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