1,721,075 research outputs found
The increasing and evolving pediatric IBD: a single centre focus on “old” and “new” patients.
No full textHepatic Methionine-enkephalin may interfere with response to antiviral therapy in chronic hepatitis C
No full textAbstract: Background The immunoreactivity of methionine-enkephalin (Met-enkephalin), one of the endogenous opioid peptides, is expressed in the liver in different types of chronic diseases. This finding suggests that the liver may be a source of endogenous opioids in disease state. In-vitro studies have shown that morphine, which exerts its effect by binding to opioid receptors, enhances hepatitis C virus replication and that it interferes with the antiviral effects of interferon. Thus, it was hypothesized that liver-derived endogenous opioids, which also bind to opioid receptors, may interfere with the response to antiviral therapy with interferon.
Aim To correlate the expression of Met-enkephalin immunoreactivity (MEIR) in the liver of patients with chronic hepatitis C with their response to treatment with pegylated interferon and ribavirin.
Methods We sought to investigate the expression of the immunoreactivities of Met-enkephalin and of the d-opioid receptor 1 (DOR1), to which Met-enkephalin binds, preferentially, in liver samples from 23 patients with chronic hepatitis C who had undergone antiviral therapy. Twelve patients obtained a sustained virological response, and 11 patients were relapsers after or nonresponders to treatment. Among the 12 patients with sustained virological response, one patient (8.3%) expressed MEIR and another one expressed DOR1 immunoreactivity (8.3%), whereas none of the patients expressed both immunoreactivities. Among the group of nonresponders/relapsers, one patient expressed MEIR (9%), two patients expressed DOR1 immunoreactivity (18.2%), and seven patients expressed both (63.6%). The difference between responders and nonresponders in the expression of both immunoreactivities was significantly different (P<0.001).
Conclusion Our data are in favor of the hypothesis that enhanced expression of MEIR and DOR1 immunoreactivity correlates with poor response to antiviral therapy that includes interferon. Thus, this study provides a rationale to study the effect of opiate antagonists in combination with antiviral therapy with interferon and ribavirin in patients who express MEIR in the liver and who have not responded to or who have relapsed after treatment with those antiviral medications
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
Wilson disease: Histopathological correlations with treatment on follow-up liver biopsies
No full textAIM:
To investigate the progression of hepatic histopathology in serial liver biopsies from Wilson disease (WD) patients.
METHODS:
We report a group of 12 WD patients treated with zinc and/or penicillamine who underwent multiple follow-up liver biopsies. Demographic, clinical and laboratory data were gathered and all patients underwent an initial biopsy and at least one repeat biopsy.
RESULTS:
Time to repeat biopsy ranged from 2 to 12 years. Six patients (non-progressors) showed stable hepatic histology or improvement. In one case, we observed improvement of fibrosis from stage 2 to 0. Six patients (progressors) had worsening of fibrosis. There was no significant correlation between the histological findings and serum aminotransferases or copper metabolism parameters. The hepatic copper concentration reached normal levels in only two patients: one from the non-progressors and one from the progressors group. The estimated rate of progression of hepatic fibrosis in the entire group was 0 units per year in the time frame between the first and the second liver biopsy (4 years), and 0.25 between the second and the third (3 years). In the progressors group, the rate of progression of liver fibrosis was estimated at 0.11 fibrosis units per year between the first and second biopsy and, 0.6 fibrosis units between the second and third biopsy.
CONCLUSION:
The inability of clinical tools to detect fibrosis progression in WD suggests that a liver biopsy with hepatic copper quantification every 3 years should be considered
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