1,721,063 research outputs found
Direct contribution of epithelium to organ fibrosis : epithelial-mesenchymal transition
No full textFibrosis of epithelial parenchymal organs and end-stage organ failure represent the final common pathway of many chronic diseases and are a major determinant of morbidity and mortality worldwide. Fibrosis is a complex response initiated to protect the host from an injurious event; nevertheless, it leads to serious organ damage when it becomes independent from the initiating stimulus. It involves massive deposition of matrix by an expanded pool of fibrogenic cells, disruption of the normal tissue architecture, and parenchymal destruction. Fibroblasts, the effector cells of matrix production, when engaged in fibrogenesis, display the highly activated phenotype characteristic of myofibroblasts. These cells are present in a large number in sites with ongoing inflammation, reparative reaction, and fibrosis, but their origin has not yet been definitely elucidated. Although proliferation of preexisting stromal fibroblasts and, probably, recruitment of bone marrow-derived fibrogenic cells may account for a portion of them, emerging evidence seems to indicate that an important number of matrix-producing fibroblasts/myofibroblasts arises through a mechanism of epithelial-mesenchymal transition. Through this process, epithelial cells would lose intercellular cohesion and would translocate from the epithelial compartment into the interstitium where, gaining a full mesenchymal phenotype, they could participate in the synthesis of the fibrotic matrix. Epithelial-mesenchymal transition is induced by the integrated actions of many stimuli including transforming growth factor-beta and matrix-generated signals that are also known to be implicated in inflammation, repair responses, and fibrosis. The consequences of epithelial-mesenchymal transition in chronic fibrosing diseases could be two-fold as follows: on one hand, by supplementing new mesenchymal cells, it might feed the expanding pool of interstitial fibroblasts/myofibroblasts responsible for the matrix accumulation; on the other hand, it could cause loss of epithelial cells, thus, contributing to the parenchyma destruction seen in advanced fibrosis. Markers of epithelium undergoing epithelial-mesenchymal transition include loss of E-cadherin and cytokeratin; de novo expression of fibroblast-specific protein 1/S100A4, vimentin, and alpha-smooth muscle actin; basement membrane component loss; and production of interstitial-type matrix molecules such as fibronectin and type I/III collagen. Evidence of epithelial-mesenchymal transition has been reported in the kidney, lung, liver, eye, and serosal membranes suggesting that epithelial-mesenchymal transition could be involved in the pathogenesis of fibrotic disorders in these organs. Thus, because of its fibrogenic potential, the detection of epithelial-mesenchymal transition in biopsy specimens could be useful diagnostically and represent a new biomarker of progression in chronic fibrosing diseases
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
Primary cutaneous coccidioidomycosis in an Italian nun working in South America and review of published literature
No full textCoccidioidomycosis is a systemic disease caused by the dimorphic fungus Coccidioides, endemic in parts of the Southwestern USA and Central and South America. Two species, Coccidioides immitis and Coccidioides posadasii, were differentiated. Primary cutaneous coccidioidomycosis (PCC) has been reported rarely. An unusual case of PCC characterized by a persistent solitary lesion diagnosed in Italy in an immunocompetent Italian nun living in Argentina is described. The isolate was identified by sequence analysis as C. posadasii. Antibody screening was negative. A total of 39 cases of PCC have been reported in the literature. Infections occurred as a consequence of traumatic implantation in a natural setting in endemic areas or of accidental inoculation in laboratory workers. Importance of accurate investigation of travel history and of occupational hazards to laboratory workers is outlined
Soft tissue sacrococcygeal chordoma with intracytoplasmic filamentous inclusions
No full textExtraskeletal chordoma arising within soft tissue is a rare occurrence. We report a case of chordoma that is unusual both for its location within the subcutaneous soft tissue of the sacrococcygeal region without involvement of adjacent bones and for the presence of eosinophilic roundish inclusion bodies within the cytoplasm of tumor cells. These bodies revealed immunoreactivity for cytokeratin and a fibrillar, partly whorled structure on the electron microscopic examination, consistent with an intermediate filament-based composition. To our knowledge, this is the first report of chordoma featuring this cellular change although we do not know the significance of these bodies
Superior vena cava reconstruction using heterologous pericardial tube after extended resection for lung cancer
No full textSuperior vena cava (SVC) resection for lung cancer is feasible in selected patients, but the type of vessel reconstruction is still object of debate. We report a case of SVC revascularization successfully performed with heterologous 'custom-made' pericardial tube. This type of revascularization may improve the reconstruction of large mediastinal veins after their resection for malignancie
Fabry disease: the role of renal biopsy in three females with mild clinical symptoms
No full textFabry's diseases (FD) is a rare X-linked lipid storage disorder due to a deficient lysosomal a-galactosidase A (a-GAL) activity. In males with the classic phenotype this metabolicleads to the intracellular accumulation of neutral GL throughout the body, mainly in kidney, heart and brain causing severe multisystemic failure. Heterozygous females are generally asymptomatic carriers and reanl biopsy is rarely performed. Conclusions: In female carriers of the Fabry's gene, renal biopsy should be considered if there is persistent proteinuria
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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