1,721,105 research outputs found
Diabetes-linked zinc transporter ZnT8 is a homodimeric protein expressed by distinct rodent endocrine cell types in the pancreas and other glands
No full textCopyright © 2008 Elsevier B.V. All rights reserved.Background and aimsZinc is abundant in pancreas, being required by endocrine islet cells for hormone secretion and by exocrine acinar cells as pancreatic juice component. ZnT8 is a member of the SLC30A family of zinc transporters whose overexpression in cultured pancreatic beta cells leads to increased insulin secretion in response to glucose, suggesting a possible role in regulating glycemia. ZnT8 was therefore proposed as a therapeutic target for diabetes, and recent genome-wide association studies identified polymorphisms in the ZNT8 gene conferring increased type 2 diabetes risk.Methods and resultsAs limited information was available on the biochemical properties of ZnT8 and on its endogenous expression, we have raised a specific polyclonal antibody and immunostained protein extracts, cell lines and tissue sections. We show that ZnT8 forms a very stable dimer that requires biological membranes to properly assemble. We demonstrate localization of murine ZnT8 to the secretory granules in pancreatic beta and alpha islet cells. Moreover, we show that ZnT8 is also expressed in other secretory cell types, namely the cubical epithelium that lines thyroid follicles and the cortex of the adrenal gland, suggesting a more widespread role in endocrine secretion.ConclusionWe provide novel insights into the features of the ZnT8 transporter, of special relevance in light of its proposed role as therapeutical target for diabetes treatment.C. Murgia, C. Devirgiliis, E. Mancini, G. Donadel, P. Zalewski and G. Perozz
Stress and nursing : study to evaluation the level of satisfaction in nurses (Stress e lavoro infermieristico: indagine conoscitiva sulla soddisfazione di un gruppo di infermieri
No full textNot unfrequently stress in nurses is related to work organization. The literature shows that the nursing profession has a high risk of psychological stress. Stress is one of the factors that contributes to inefficiency, increasing staff turnover and sick leave, and reduces the quality and quantity of care , affecting health costs and diminishing work satisfaction. This article presents the results of a study performed to evaluate 34 variables, constituting the Nursing Stress Scale (NSS) , and their level in the nursing staff of a Rome specialistic hospital. Of the 80 nurses who received the questionaire , 49 responded, a sufficient number to make the results of the study significant. The authors illustrate the methods used together with some socio-demographic considerations and how some of these can be correlated to the 7 factors adopted for multi-variate analysis. The results obtained were concordant with those described in the literature, confirming that poor organization and conflictual or ambiguous work roles negatively affect well-being and that nursing directors should bear this in mind when aiming to create a harmonious work environmen
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
Lung adenocarcinoma originates from retrovirus infection of proliferating type 2 pneumocytes during pulmonary post-natal development or tissue repair
Full text linkJaagsiekte sheep retrovirus (JSRV) is a unique oncogenic virus with distinctive biological properties. JSRV is the only virus causing a naturally occurring lung cancer (ovine pulmonary adenocarcinoma, OPA) and possessing a major structural protein that functions as a dominant oncoprotein. Lung cancer is the major cause of death among cancer patients. OPA can be an extremely useful animal model in order to identify the cells originating lung adenocarcinoma and to study the early events of pulmonary carcinogenesis. In this study, we demonstrated that lung adenocarcinoma in sheep originates from infection and transformation of proliferating type 2 pneumocytes (termed here lung alveolar proliferating cells, LAPCs). We excluded that OPA originates from a bronchioalveolar stem cell, or from mature post-mitotic type 2 pneumocytes or from either proliferating or non-proliferating Clara cells. We show that young animals possess abundant LAPCs and are highly susceptible to JSRV infection and transformation. On the contrary, healthy adult sheep, which are normally resistant to experimental OPA induction, exhibit a relatively low number of LAPCs and are resistant to JSRV infection of the respiratory epithelium. Importantly, induction of lung injury increased dramatically the number of LAPCs in adult sheep and rendered these animals fully susceptible to JSRV infection and transformation. Furthermore, we show that JSRV preferentially infects actively dividing cell in vitro. Overall, our study provides unique insights into pulmonary biology and carcinogenesis and suggests that JSRV and its host have reached an evolutionary equilibrium in which productive infection (and transformation) can occur only in cells that are scarce for most of the lifespan of the sheep. Our data also indicate that, at least in this model, inflammation can predispose to retroviral infection and cancer
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