1,720,955 research outputs found
Hepatology Elsewhere. The value of identifying hepatitis C virus in liver pathology specimens.
No full textHepatic Stellate Cell Immunodetection and Cirrhotic Evolution of Viral Hepatitis in Liver Allografts.
No full textPatients with chronic viral hepatitis are at high risk of developing cirrhosis, but the outcome of the disease in a given patient is unpredictable. Hepatic stellate cells have been demonstrated to be the most important cell type involved in hepatic fibrogenesis, regardless of the cause of the liver injury. The alpha isotype of actin (a phenotypic marker of smooth muscle cells) may be expressed by hepatic stellate cells, reflecting their "activation" to myofibroblast-like cells. The present study aimed to analyze the expression of alpha-smooth muscle actin-positive hepatic stellate cells in liver allografts with recurrent viral hepatitis, and to evaluate whether and how such expression may be related to the outcome of the disease. Using immunohistochemistry and a semi-quantitative scoring system, the expression of a-smooth muscle actin in hepatic stellate cells was analyzed in liver allografts of 17 patients with recurrent viral hepatitis. They included nine patients who developed cirrhosis at the end of follow-up (mean time 23.6 months), and eight patients with no cirrhosis at the end of a comparable follow-up time (mean 30.1 months). In all patients, liver biopsy specimens were obtained between 3 and 6 months (t1) and between 10 and 15 months (t2) after transplantation. Preperfusion biopsy specimens of donor livers served as a baseline (t0). By comparison with the baseline biopsy, an increased number of alpha-smooth muscle actin-expressing hepatic stellate cells was observed in all cases in t1 biopsies. An increase in the amount of alpha-smooth muscle actin-positive hepatic stellate cells in zone 1 at t1 was significantly (P < .006) related to subsequent cirrhotic evolution. In conclusion, in liver allografts with recurrent viral hepatitis, the activation of hepatic stellate cells is an early event. An increased number of alpha-smooth muscle actin-positive hepatic stellate cells in zone 1 may represent an unfavorable event related to cirrhotic evolution
Increased hepatic iron deposition resulting from treatment of chronic hepatitis C with ribavirin.
No full textIncreased levels of hepatic iron may impair the response of patients with chronic hepatitis C to treatment with interferon-alfa, but combination therapy with ribavirin has demonstrated efficacy in the treatment of hepatitis C. When used alone or with interferon-alfa, ribavirin may cause a dose-dependent reversible hemolytic anemia. We compared the extent and cellular localization of iron deposition in liver tissue from biopsy specimens obtained before and after 36 weeks of therapy with ribavirin or placebo for 59 patients with chronic hepatitis C. Paired slides were available for review from 26 ribavirin and 27 placebo recipients. Iron deposition was assessed using coded slides stained with Perls Prussian blue and was semi-quantitated in hepatocytes, Kupffer cells, and areas of fibrosis. The overall iron score fell by 0.96 in the placebo group and increased 1.69 in the ribavirin recipients. Iron was deposited mainly in hepatocytes; the hepatocyte iron score increased from 2.19 to 3.81 in the ribavirin group. The amount of iron staining in Kupffer cells declined in the placebo group and increased slightly in the ribavirin group. Iron changes in areas of fibrosis were minor and did not differ between groups. Increased total hepatic iron deposition occurred during a 9-month course of ribavirin. Ribavirin-associated hemolysis deposits iron preferentially in hepatocytes. This increased deposition of hepatic iron does not seem to affect the biochemical or histologic response to ribavirin therapy but may have implications for hepatocyte susceptibility to future injury
Going 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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