1,721,086 research outputs found
Fibrosis assessment in patients with HCV or HBV chronic infection
No full textMeanwhile, measurement of liver stiffness (LS) is the standard for fibrosis screening in patients with chronic hepatitis C virus (HCV) and chronic hepatitis B virus (HBV), namely for the diagnosis of severe fibrosis and cirrhosis (F3 or F4 according to the METAVIR scoring system, respectively) and for the exclusion of significant fibrosis. LS values can be influenced by the degree of necroinflammation in both HBV and HCV infection. In particular, the international guidelines suggest considering normal ALT versus elevated ALT (5 × ULN) in the measurement of LS in HBV-infected patients. Several studies were performed using transient elastography to evaluate its reliability in defining the presence of portal hypertension and esophageal varices. A wide range of cut-off levels have been reported to date. LS is also a strong pre-treatment predictor with regard to the response to antiviral treatment. The precise distinction between advanced fibrosis and cirrhosis is of fundamental importance in terms of both diagnostic and therapeutic approaches. Regression of fibrosis has been demonstrated in patients with HCV after virus elimination and in patients with HBV during antiviral treatment. In HCV patients, a sustained virological response was accompanied by a significant improvement in hepatic function and a decrease of LS. In HBV patients, pre-treatment and LS changes during nucleoside/nucleotide analogues can predict liver-related events. In conclusion, LS measurement has become essential for the clinical management of patients with HCV and HBV chronic infection
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
Serotonin receptors and their role in the pathophysiology and therapy of irritable bowel syndrome
No full textIrritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal discomfort, pain and changes in bowel habits, often associated with psychological/psychiatric disorders. It has been suggested that the development of IBS may be related to the body's response to stress, which is one of the main factors that can modulate motility and visceral perception through the interaction between brain and gut (brain-gut axis). The present review will examine and discuss the role of serotonin (5-hydroxytryptamine, 5-HT) receptor subtypes in the pathophysiology and therapy of IBS
Serotonin receptors and their role in the pathophysiology and therapy of irritable bowel syndrome
No full textBACKGROUND: Irritable bowel syndrome (IBS) is a functional disorder of the
gastrointestinal tract characterized by abdominal discomfort, pain and changes in
bowel habits, often associated with psychological/psychiatric disorders. It has
been suggested that the development of IBS may be related to the body's response
to stress, which is one of the main factors that can modulate motility and
visceral perception through the interaction between brain and gut (brain-gut
axis). The present review will examine and discuss the role of serotonin
(5-hydroxytryptamine, 5-HT) receptor subtypes in the pathophysiology and therapy
of IBS.
METHODS: Search of the literature published in English using the PubMed database.
RESULTS: Several lines of evidence indicate that 5-HT and its receptor subtypes
are likely to have a central role in the pathophysiology of IBS. 5-HT released
from enterochromaffin cells regulates sensory, motor and secretory functions of
the digestive system through the interaction with different receptor subtypes. It
has been suggested that pain signals originate in intrinsic primary afferent
neurons and are transmitted by extrinsic primary afferent neurons. Moreover, IBS
is associated with abnormal activation of central stress circuits, which results
in altered perception during visceral stimulation.
CONCLUSIONS: Altered 5-HT signaling in the central nervous system and in the gut
contributes to hypersensitivity in IBS. The therapeutic effects of 5-HT
agonists/antagonists in IBS are likely to be due also to the ability to modulate
visceral nociception in the central stress circuits. Further studies are needed
in order to develop an optimal treatment
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