1,720,977 research outputs found
Markers of acute rejection and graft acceptance in liver transplantation.
Full text linkThe evaluation of the immunosuppression state in liver transplanted patients is crucial for a correct post-transplant management and a major step towards the personalisation of the immunosuppressive therapy. However, current immunological monitoring after liver transplantation relies mainly on clinical judgment and on immunosuppressive drug levels, without a proper assessment of the real suppression of the immunological system. Various markers have been studied in an attempt to identify a specific indicator of graft rejection and graft acceptance after liver transplantation. Considering acute rejection, the most studied markers are pro-inflammatory and immunoregulatory cytokines and other proteins related to inflammation. However there is considerable overlap with other conditions, and only few of them have been validated. Standard liver tests cannot be used as markers of graft rejection due to their low sensitivity and specificity and the weak correlation with the severity of histopathological findings. Several studies have been performed to identify biomarkers of tolerance in liver transplanted patients. Most of them are based on the analysis of peripheral blood samples and on the use of transcriptional profiling techniques. Amongst these, NK cell-related molecules seem to be the most valid marker of graft acceptance, whereas the role CD4+CD25+Foxp3+ T cells has still to be properly defined
Low levels of G17 and Barrett esophagus: A clinical relationship
No full textBackground & Aims: In clinical practice, most patients with symptoms suggestive of gastroesophageal reflux
disease (GERD) undergo esophago-gastro-duodenoscopy (EGD), despite its low sensitivity in detecting reflux
stigmata. Gastrin 17 (G-17) has been proposed to be related with GERD, due to the negative feedback between
acid secretion and this hormone. We assessed the clinical usefulness of fasting G-17 serum determination for
a non-invasive diagnosis of GERD in patients with typical symptoms.
Methods: We consecutively enrolled patients complaining of typical GERD symptoms in two different settings:
a single referral center and a primary care setting. Control groups consisted of dyspeptic patients. All subjects
underwent assessment of serum levels of G-17 and EGD.
Results: At the academic hospital, 100 GERD patients (n=89 with erosive esophagitis and 11 with Barrett’s
esophagus) had statistically significant low levels of G-17 as compared with 184 dyspeptic patients (1.7±1.2
pg/L vs 8.9±5.7 pg/L p<0.0001). Similarly, in the primary care setting, 163 GERD patients had statistically
significant low levels of G-17 as compared with 132 dyspeptic patients (0.5±0.2 pg/L vs. 4.0±2.6 pg/L,
p<0.0001). Moreover, in the primary care setting, no statistically significant differences were found for G-17
levels between patients with erosive and non-erosive reflux pattern (0.4±0.2 vs 0.7±0.3; p=0.08). In primary
care, the accuracy of G-17 less than 1 pg/L to diagnose non-invasively GERD was 94.3%.
Conclusions: Low levels of G-17 were detected in patients with erosive esophagitis and Barrett’s esophagus in a
referral center and in patients with typical GERD symptoms in a sample of patients from a primary care setting
Increased thrombin generation in liver transplant recipients: does immunosuppressive therapy play a role?
No full textGoing 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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