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Prebiotici e probiotici nel trattamento delle epatopatie. Giornale di Gastroenterologia 2004;9:59-70
No full textPrevention of colonic fibrosis by Boswellia and Scutellaria extracts in rats with colitis induced by 2,4,5-trinitrobenzene sulphonic acid
No full textBackground Currently, no effective preventive measures or medical therapies are available for intestinal
fibrosis and, thus, surgery remains the only available strategy in the management of fibrostenotic enteropathies,
especially Crohn’s disease. The aim of this study was to evaluate the efficacy of a combined therapy of
anti-inflammatory Boswellia and antifibrotic Scutellaria extracts on the development of colonic fibrosis in rats.
Materials and methods Chronic colonic inflammation-associated fibrosis was induced in rats by intracolonic
administration of 2,4,5-trinitrobenzene sulphonic acid (TNBS). Sixty-four healthy male Sprague-Dawley rats
were assigned to five groups: 8 controls, 14 TNBS, 14 TNBS orally treated with Boswellia extracts
(50 mg kg–1 day–1), 14 TNBS orally treated with Scutellaria extracts (150 mg kg–1 day–1), and 14 TNBS orally
treated with both Boswellia (50 mg kg–1 day–1) and Scutellaria extracts (150 mg kg–1 day–1). The colon was
removed after 21 days of treatment and assessed by macroscopic, histological, morphometric and
immunohistochemical analyses. For immunohistochemical analysis, alpha-smooth muscle actin (α-SMA),
collagen types I–III, connective tissue growth factor (CTGF), transforming growth factor-beta1 (TGF-β1), Smad3,
Smad7 and CD3 antibodies were used.
Results Combined oral administration of Boswellia and Scutellaria significantly improved the course and
macroscopic findings of TNBS-induced chronic colitis assessed by disease activity index, colon weight, length,
adhesions, strictures, dilatation, thickness, oedema, ulcerations and extension of damage. The histological
severity of the colonic fibrosis was also notably improved by the treatment and associated with a significant
reduction in the colonic expression of α-SMA, collagen I–III, CTGF, TGF-β1, Smad3, and Smad7.
Conclusions These data demonstrate that the prophylactic administration of anti-inflammatory Boswellia and
antifibrotic Scutellaria extracts is effective in preventing colonic fibrosis in TNBS-induced colitis. Their antifibrotic
mechanism of action seems to be mediated by the inhibition of TGF-β1/Smad3 pathway
Targeted disruption of Smad3 confers resistance to the development of dimethylnitrosamine-induced hepatic fibrosis in mice
No full textBackground: Hepatic fibrosis is characterized by a progressive accumulation of fibrillar
extracellular matrix (ECM) proteins including collagen, which occurs in most types of
chronic liver diseases. Transforming growth factor-b (TGF-b)/Smad3 signalling plays a
central role in tissue fibrogenesis, acting as a potent stimulus of ECM accumulation.
Aim: To evaluate the potential protective role of Smad3 deficiency in the pathogenesis
of liver fibrosis induced by dimethylnitrosamine (DMN) in Smad3 null mice.
Methods: Chronic hepatitis-associated fibrosis was induced in 13 Smad3 null and
13 wild-type (WT) mice by intraperitoneal DMNadministration (10 mg/g body weight/
day) for three consecutive days per week for 6 weeks. The liver was excised for
macroscopic examination and histological, morphometric and immunohistochemical
(IHC) analyses. For IHC, a-smooth muscle actin (a-SMA), collagen types I–III, TGFb1,
connective tissue growth factor (CTGF), Smad3, Smad7 and CD3 antibodies were
used. Results: At macroscopic examination, the liver of DMN-treated Smad3 WT
appeared harder with a dark brown colouring and necrotic areas compared with that
from null mice.Histological and morphometric evaluation revealed a significantly higher
degree of hepatic fibrosis and accumulation of connective tissue in the Smad3 WT
compared with null mice. IHC evaluation showed a marked increase in a-SMA, CTGF,
collagen I-III, TGF-b and Smad3 staining in the liver of Smad3 WT compared with that
in null mice, whereas Smad7 was increased only in null mice. Conclusions: The results
indicate that Smad3 loss confers resistance to the development of DMN-induced hepatic
fibrosis. The reduced fibrotic response appears to be due to a reduction of fibrogenic
myofibroblast activation and ECM production and accumulation. Smad3 could be a
novel target for potential treatment of fibrosis complicating chronic hepatitis
Prevention of TNBS-induced colonic fibrosis in rats by boswellia and scutellaria extracts.
No full text
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
Smad3-null mice lack interstitial cells of Cajal in the colonic wall
No full textBACKGROUND: Transforming growth factor-beta (TGF-beta)/Smad's signalling pathway
plays a pivotal role in organogenesis, oncogenesis, inflammation, repair and
fibrosis. The aim of this study was to evaluate the morphology of muscle layers
and the density and distribution of interstitial cells of Cajal (ICC) in the
colon of Smad3 knockout mice.
MATERIALS AND METHODS: Eighteen Smad3 wild-type mice and 12 null mice were
sacrificed at age 4 months and the colons were collected for histology
(Haematoxilin-Eosin, Masson thrichrome and Gomori silver staining), morphometry
and immunohistochemistry (IHC) analysis. For IHC we used the c-Kit, alpha-smooth
muscle actine (alpha-SMA), vimentin, desmin and neuronal cocktail (S-100, NSE,
neurofilament 200) antibodies.
RESULTS: When sacrificed, 40% of the null mice showed different degrees of colon
dilatation when compared with the wild-type. Histological and morphometric
evaluation revealed a significant reduction in muscle layer thickness of the
colon in all the null mice when compared with the wild-type. Immunohistochemistry
evaluation showed a marked reduction, or even absence, of c-Kit immunoreactivity,
which identifies ICC, in the colon of all the null mice, compared with the
wild-type.
CONCLUSIONS: Smad3 null mice showed a marked reduction, or even absence, of ICC
in the colon together with a concomitant reduction of intestinal smooth muscle
layer thickness. This data could account for the colonic dilation observed in
approximately 40% of the Smad3 null mice. Alteration of intestinal smooth muscle
layers and ICC could also be involved in the resistance of the Smad3 null mice to
develop colonic fibrosis
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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