1,721,031 research outputs found
Pleiotropism of human herpes virus-8 in Kaposi's Sarcoma : infection of endothelial progenitor cell and altered maturation of B lymphocytes
No full textHuman herpesvirus 8 (HHV8), is an essential factor in the pathogenesis of Kaposi's sarcoma (KS). In addition to KS, HHV8 is also involved in the pathogenesis of two lymphoproliferative disorders: primary effusion lymphoma (PEL) and the plasma cell variant of multicentric Castleman's disease (MCD). It has also been linked to other, non-malignant, clinical manifestations such as bone marrow failure in transplant recipients and haemophagocytic syndrome. Therefore, HHV-8 infection has a “pleiotropic effects” because the virus can promote different pathological conditions; however, the precise events leading to the develop of the different diseases still remain poorly defined. One fundamental unresolved question regards the cellular reservoirs of HHV8 and the exact nature of the putative HHV8-infected circulating precursor of spindle cells the hallmark cells of KS lesions. Because KS spindle cells are thought to be of endothelial origin our attention was focalized on circulating hematopoietic precursors able to differentiate into endothelial lineage. Furthermore, B cells are now defined as one of the principal circulating HHV8-reservoir able to sustain the lytic reactivation and dissemination of the virus. However, the consequences of HHV-8 infection of B cells in KS patients have been poorly characterized so far. Therefore, in this study we investigated also whether the frequency and/or the immunophenotypic profile of different peripheral B cell subsets were affected in patients with cKS. Methods and Findings: Endothelial progenitor cells (EPCs) were quantified by flow cytometry and were found increased in the peripheral blood of patients with cKS. Late endothelial progenitor cells (late-EPCs) were cultured from the peripheral blood mononuclear cells of patients and the presence and load of KSHV genomes were analyzed by real-time PCR in DNA extracted from cells and supernatants of late-EPC cultures. Late-EPC cultures were found to harbor KSHV-DNA at variable levels and to retain the virus after multiple passages in cells as well as in supernatants, suggesting that a quote of KSHV lytic infection may spontaneously occur. Lytic phase induction or hypoxia could amplify virus release in supernatants. Moreovere, late-EPCs could be infected in vitro by HHV8, supporting the hypothesis that these cells are one of the more important virus target. Then, we used flow-cytometry to evaluate the frequency of circulating B cells and their subpopulations in cKS patients. Analysis of the peripheral blood of patients compared to age and sex matched controls, showed that in cKS patients the frequency of circulating CD19, naïve, pre-naïve and transitional B cells were increased in patients with cKS. Conversely, the frequency of memory B cells
(class-switched, IgM Memory and CD27- memory B cells) was decreased in cKS patients compared to healthy controls. Finally, Marginal Zone-like B cells did not change between groups. Conclusion: Our results suggest that circulating endothelial progenitors from KS patients are increased in the peripheral blood of cKS patients and are HHV8-infected. Moreover, they support viral productive replication and may therefore represent potential virus reservoirs and putative precursors of KS spindle cells. In addiction, our results clearly indicate that circulating B cells are altered in patients with cKS, with an expansion of B cells in the early stages and a concomitant reduction of memory B cells
Attribuito a Taddeo Carlone, Marcantonio I, conte di Tassarolo, Ettore e Ottavio Spinola di Luccoli
No full textIdentificazione delle radici figurative, attribuzione a Taddeo Carlone e presentazione storico-critica di un inedito rilievo raffigurante il primo conte di Tassarolo, Marcantonio Spinola di Luccoli e i suoi fratell
Role Based Access Control for the interaction with Search Engines: the COOPER Experience
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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