1,721,199 research outputs found
Risk of gastric neoplasms in autoimmune atrophic gastritis and its relationship with gastric microbiota and immune pathways
Full text linkAutoimmune atrophic gastritis (AAG) is a slowly progressive organ-specific, immune-mediated condition, characterized by atrophy of the oxyntic mucosa with subsequent hypochlorhydria and hypergastrinemia. When this pathological process occurs, the subsequent reduced mass of specialized parietal cells can lead to impaired gastric acid and intrinsic factor secretion, eventually resulting in malabsorption of iron and vitamin B12 with consequent iron deficiency and/or pernicious anemia as well as an impairment of gastric microbiota composition and an increased risk of gastric tumours. The prevalence of AAG in the general population is estimated to be as high as 2-5%. Patients affected by AAG are likely to develop several neoplasms, in particular type-1 neuroendocrine tumors in percentage variable from 0.4% to 7% and gastric cancer (GC) with an incidence ranging between 0% and 1.8% per year. In AAG, the development towards GC depends on several factors such as conditions leading to an increased intragastric pH and oxidative stress, gastric microbiota composition, host factors such as the immune pathway, rather than environmental risk factors like smoke, alcohol, body mass index and diet. The increased GC risk associated to AAG emphasizes the importance of diagnosing and monitoring these patients, as recommended by the last European guidelines on diagnosis and management of precancerous gastric conditions (MAPS II). Many questions regarding the natural history of AAG and the risk factors for the development of GC in patients affected by AAG are still opened. On the basis of this scenario, several monocentric and multicentric studies were conducted within this PhD project with the aim to in-depth assess several clinical, biochemical, histological and immunological aspects, not previously investigated, that may contribute to better understand the natural history of AAG as well as the risk factors involved in gastric carcinogenesis and the best management of this gastric precancerous condition. Considering the studies performed on gastric microbiota and immunological pathways in AAG, we can consider them as the first pieces of evidence, and they certainly cannot be interpreted as a point of arrival but should rather be viewed as a starting point for future research in this very complex and intriguing field in which much work is yet to be done
Retinoic acid modulates gap junctional intercellular communication in hepatocytes and hepatoma cells
No full textGap junctional communication permits the direct exchange of small molecules and ions and has been implicated in tissue homeostasis/metabolite exchange. The lack of gap junctional intercellular communication (GJIC) plays important roles in the promotion and progression of carcinogenesis. In the present study, we demonstrate that treatment of human hepatoma Hep G2 cells with retinoic acid (RA) results in increased amounts and phosphorylation of connexins, their stabilisation in plasma membrane plaques and enhanced GJIC. In cultured fetal hepatocytes, which represent a non-transformed, proliferating and incompletely differentiated liver system, the effects of RA are limited to the establishment of connexin in areas of cell-cell contact and the improvement of GJ1C. This suggests that modulation of cell-cell channel communication by RA occurs differently in these two experimental models: while RA is able to revert cell transformation in Hep G2 cells, in fetal hepatocytes it may induce the expression of a more differentiated phenotype
The lobular expression of the rat asialoglycoprotein receptor is regulated at post-transcriptional level
No full textThe purpose of this study was to define the distribution of the
asialoglycoprotein receptor (ASGP-R) main peptide, rat hepatic lectin
(RHL)-1, within the rat liver lobule and to investigate its possible modulation
in physiological states characterised by marked changes of receptorial
expression. In particular, we chose livers from rats partially hepatectomised
or at the end of pregnancy, as models, respectively, of decreased or increased
expression of the ASGP-R, and used the in situ hybridisation and
immunocytochemistry techniques to analyse in parallel the lobular
distributions of RHL-1 mRNA and protein. In normal rat liver, although the
RHL-1 mRNA was homogeneously distributed, the RHL-1 peptide was
predominantly localised on the surface of pericentral hepatocytes with a
gradient of expression towards the periportal zone. This gradient of
expression of RHL-1 peptide was reduced in regenerating livers, in which the
positive stain was restricted to a few layers of cells around the central vein. In
contrast, livers at the end of pregnancy showed an overall increase of the
peptide with a concomitant flattening of the gradient across the liver plate. In
all the conditions, we never observed important changes in the pattern of
expression of the specific mRNA. These findings indicate that the distribution
of ASGP-R is heterogeneous across the liver lobule, with a pattern of
expression prevalently modulated at the posttranscriptional level
Almaworld: Data visualization to support international research collaborations
No full textMonitoring and evaluating research activities and their results can be intended as initiatives devoted to support universities and research institutes policymakers and governments while enhancing international relationships with colleagues from foreign affiliations. In this context, the integration of data coming from multiple and different sources, as well as the adoption of data visualization techniques can play a strategic role, letting the users browse official and reliable data by means of proper and effective user interface and interaction mechanisms. In this paper, we present AlmaWorld, a web application designed and developed to map the international co-authorships of the professors and the researchers of the University of Bologna, by exploiting two dimensions: the spatial and the temporal ones. The paper presents the approaches we have adopted in the design phase and a prototype we have developed
Special Issue: “Advances in Immunotherapy for Cancer: From Molecular Basis to Novel Biomarkers and Therapeutic Targets”
Full text linkOver the past decade, immunotherapy has revolutionized the treatment of cancer, emerging as a novel pillar of cancer therapy and markedly improving patient survival across multiple tumor types [...
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
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