1,720,963 research outputs found
LYMPHOMA CELL LINES: IN VITRO MODELS FOR THE STUDY OF HHV-8+ PRIMARY EFFUSION LYMPHOMA (BODY CAVITY-BASED LYMPHOMAS)
No full textPrimary effusion lymphoma (PEL; also known as body cavity-based lymphoma) is recognized as a new and unique lymphoma entity occurring predominantly, but not exclusively in human immunodeficiency virus (HIV)-seropositive patients with acquired immunodeficiency syndrome (AIDS). PEL grows exclusively in body cavities as serous lymphomatous effusion without evidence of mass disease or dissemination. Their most unique feature is infection with the newly discovered human herpesvirus-8 (HHV-8; also known as Kaposi's sarcoma-associated herpesvirus), often accompanied by co-infection with Epstein-Barr virus (EBV). A number of continuous lymphoma cell lines have been established from the malignant pleural effusion, ascitic fluid and peripheral blood of patients with AIDS- and non-AIDS-associated PEL. While all cell lines are HHV-8+, about half of them also contain EBV sequences. Stimulation of the cell lines causes switch from latent to lytic HHV-8 infection. The cells are generally negative for T and B cell immunomarkers (except for CD138 suggesting a pre- or terminal plasma cell stage) and positive for some activation and adhesion markers; they are genotypically B cells with their immunoglobulin genes rearranged. Complex, hyperdiploid karyotypes with multiple structural abnormalities are seen in the cell lines examined. No alterations of known proto-oncogenes are detected in PEL, with the exception of BCL-6 mutations occurring in a large percentage of cases. Heterotransplantation of the cell lines into immunodeficient mice leads to the development of lymphomatous effusion and marked angiogenesis. As HHV-8 contains DNA sequences of several protein homologues, the cell lines express various cytokines, cytokine receptors, chemokines, cell cycle and anti-apoptosis modulators which are upregulated upon stimulation. Indeed, some cell lines produce high levels of (human) interleukin-6 and interleukin-10. Taken together, these cell lines represent very important model systems for the elucidation of the pathobiology of PEL; furthermore, the cell lines are extremely useful scientific tools providing a resource to pursue studies of HHV-8-mediated pathogenic mechanisms
HHV-8 INFECTION IS SPECIFIC FOR CELL LINES DERIVED FROM PRIMARY EFFUSION (BODY CAVITY-BASED) LYMPHOMAS
No full textHuman herpes virus 8 (HHV-8; or KSHV, Kaposi's sarcoma-associated herpes virus) is a gamma herpes virus with sequence homology to Epstein-Barr virus (EBV). It was first isolated from Kaposi's sarcoma tumor cells and subsequently from tumor cells and peripheral blood mononuclear cells from patients with primary effusion lymphomas (PEL; or body cavity-based lymphomas). PEL has been recognized as an individual nosologic entity based on its distinctive biological-pathological features and its consistent infection with HHV-8 (commonly, but not always co-infected with EBV), occurring predominantly in human immunodeficiency virus (HIV)-infected patients but occasionally also in HIV-negative cases. Whether HHV-8 sequences can be found also in non-hematopoietic tumor cells other than Kaposi's sarcoma and in malignant hematopoietic malignancies other than PEL, has been the focus of the present studies. We examined the presence of HHV-8 sequences by polymerase chain reaction (PCR) using (1) a panel of 133 human cell lines established from a large variety of solid tumors; (2) a spectrum of 114 hematopoietic cell lines derived from the different cell lineages including 50 B cell leukemia/lymphoma-derived cell lines and seven cell lines established from patients with PEL. Besides the seven PEL cell lines, 46 cell lines that were derived from malignant pleural effusion or ascitic fluid material (25 non-hematopoietic and 21 hematopoietic cell lines) were examined. Except for the seven PEL cell lines that were strongly HHV-8+ in the PCR, all solid tumor cell lines and all hematopoietic cell lines scored consistently negative for the presence of HHV-8 sequences. These results confirm the absolute specificity of HHV-8 infection (within the hematopoietic malignancies) for PEL. PEL cell lines represent useful tools for the analysis of the biology of this neoplasm and of the pathogenetic role of the virus in the disease development
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
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
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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