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Hepatitis C virus infection in patients undergoing allogeneic bone marrow transplantation.
No full text
HEPATITIS C VIRUS (HCV) INFECTION IN PATIENTS UNDERGOING THERAPY FOR HAEMATOLOGIC MALIGNANCIES
No full textHEPATITIS C VIRUS INFECTION AND LIVER FAILURE IN PATIENTS UNDERGOING ALLOGENC BONE MARROW TRANSPLANTATION
No full textThe role of hepatitis C virus (HCV) infection in severe liver failure (LF) following bone marrow transplantation is still uncertain. We therefore decided to determine the presence of HCV-RNA in 31 patients who died of severe LF after BMT and in 26 matched BMT controls who did not develop LF. HCV-RNA was identified by polymerase chain reaction and anti-HCV by second generation enzyme-linked immunoassay and by 4-band recombinant immunoblotting assay in serum samples obtained before and after BMT. Biochemical and clinical parameters of liver disease were obtained by reviewing clinical records. LF developed at a median interval of 80 days (20-570) from transplantation and was clinically assessed as VOD (n = 7), liver GVHD (n = 5) or hepatitis (n = 19). HCV-RNA was detected, respectively, in 15/31 (48%) and in 12/26 (46%) of LF patients and controls (P = 0.9). Conversely, the risk of dying of LF was 62% and 53% (P = 0.5) respectively, for HCV-RNA positive and negative patients. Anti-HCV profile did not correlate with viremia, nor with type of liver disease. These findings indicate that, despite a 47% prevalence of HCV infection in our series, HCV-RNA positivity was neither a predictor of VOD nor a marker for life-threatening liver disease
Hepatitis C virus infection in patients undergoing allogeneic bone marrow transplantation
No full textAntibody to the recently identified hepatitis C virus was investigated in sera of 128 patients treated with allogeneic bone marrow transplantation, to determine the prevalence of HCV infection and its role in post-transplant liver complications. The overall prevalence of anti-HCV positivity was 28.6% (38/128 patients). The presence of pretransplant anti-HCV positivity (in 10/35 tested patients) did not seem to predict a more severe liver disease. In fact 8/10 anti-HCV+ and 15/25 anti-HCV- patients had elevated transaminases at BMT, and posttransplant liver failure (due to VOD or subacute hepatitis), and post-BMT rises in transaminases occurred regardless of anti-HCV serology (P = 0.6 and 0.2, respectively). In patients tested for anti-HCV after BMT (n = 128), only two (one anti-HCV+ and one anti-HCV-) experienced VOD; the number of patients in whom liver failure contributed to death was comparable in anti-HCV-positive and anti-HCV- negative patients (P = 0.4). Among 17 patients with documented posttransplant seroconversion (from anti-HCV- to anti-HCV+) the appearance of anti-HCV was concomitant with hepatitis exacerbation in 9 (53%). Histologic changes demonstrated a more severe liver damage in anti-HCV+ patients: a chronic hepatitis was diagnosed in 9/11 anti-HCV+ versus 1/7 anti-HCV- cases. Based on these observations, we conclude that hepatitis C virus has a role in liver disease in such patients, although its evaluation by the anti-HCV test is still of limited accuracy, due to low sensitivity and incomplete specificity
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
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