1,721,004 research outputs found
Molecular genetics of dilated cardiomyopathy.
No full textA major advance in the study of the pathogenesis of dilated cardiomyopathy (DC) has been the identification of a familial trait in a relevant proportion of cases (more than 25\%), which indicates that, at least in these cases, a mutated gene is the cause of the disease. Familial dilated cardiomyopathy is a genetically heterogeneous disorder, most frequently with autosomal-dominant inheritance. Five different loci that cosegregate with the disease have been mapped so far; the identification of the disease genes is still in progress. The only disease gene known so far is the dystrophin gene, which causes X-linked DC. By analogy with dystrophin, it is believed that other cytoskeletal proteins could be involved in the pathogenesis of DC. Finally, in right ventricular cardiomyopathy, a peculiar form of cardiomyopathy that is frequently familial as well, several disease loci have been described. Also in this case, no disease gene has been yet identified. The advances in clinical and molecular genetics of DC have relevant clinical and therapeutic implications
[The pathogenesis of dilated cardiomyopathy: current progress].
No full textThe pathogenesis of dilated cardiomyopathy (DCM) is still unknown; however, some factors that seem to play an important role in the development of the disease have recently been identified: they are enteroviral infections, immune mechanisms and genetic factors. Enteroviral infection (particularly due to Coxsackie virus B) has long been suspected to be the cause of myocarditis and subsequent DCM. However, only recent techniques of genetic engineering have been able to demonstrate the presence of enteroviral RNA in endomyocardial biopsy of patients with DCM. The role of the viral particles contained in the myocardium is still undetermined. Changes in the immune system concerning cell-mediated and humoral immunity have been recently detected. It has been suggested that an autoimmune process could be the actual cause of DCM in some patients, rather than the consequence. The immune system is strictly related to the major histocompatibility complex. As in some autoimmune diseases, a relationship between DCM and HLA class II phenotype has been found: particularly the DR4 antigen seems to be associated with a high risk of disease. Besides immunogenetic factors, other genetic factors seem to play a role in the pathogenesis of DCM. In 6-8\% of cases a familial history of cardiomyopathy has been observed. In clinical studies on familial DCM different phenotypes have been shown, suggesting that different genetic mechanisms are involved in the pathogenesis of the disease. At least two main mechanisms can be hypothesized: the transmission of "predisposing" factors or a defect in proteins essential for the cardiac muscle cell function. Viral agents, autoimmune reactions, immunogenetic and genetic factors seem to cause myocardial damage individually or with complex interactions: the research should be devoted to these topics in the future
Influence of different fixation reagents on NIH 3T3 fibroblasts morphology: An AFM study
No full textThe Atomic force microscope (AFM) has recently become an attractive tool for biological analysis, especially for the characterization of both morphological and mechanical properties. In this study, we investigated the influence of different fixation reagents on NIH 3T3 fibroblast cells morphology. Three protocols were selected: paraformaldehyde, methanol and acetone. Height, perimeter, area, volume and roughness of cells were measured using an AFM. As expected, different fixation protocols produce different morphological changes in cells. However, to preserve fibroblastsí
morphology, the methods applying aldehyde fixations performed much better than those using either methanol or acetone. Based on quantitative assessments, fibroblasts fixed with paraformaldehyde showed the closest volume, area and perimeter values to living cells. Roughness data and a Western blot test confirmed that methanol fixation produces larger cell membrane damage, when compared to the other two fixatives
Sustainability of the plastic recycling business. Plasmix: present hurdles and future opportunities
No full textClosing the plastic recycling loop, while maintaining profitability was never easy at corporation level for several reasons. Although a challenge, complete recyclability of plastic materials must be achieved to avoid environmental collapse. The aim of the study has been to investigate upon the alternatives we currently can deploy and further develop to abate and eventually erase plastic waste. The approach has been to follow the circular economy framework of resource flow, implying that at the end of usable life, materials go back to being resources for further extraction of value instead of becoming waste. Although plastic recycling has been in place for a while, the inherent recyclability and quality of recycled products depends first and foremost on the input materials homogeneity. Recycling heterogeneous plastic waste (in Italy regarded as Plasmix, a mix of different plastic polymers) is a challenge yet to overcome, and this unrecyclable plastic share (Plasmix indeed) is still landfilled at best. Serving of the Triple-Layered Business Model Canvas combined with thorough literature resources study and direct contacts with the biggest name in the Italian Plasmix recycling business, some valuable alternatives for Plasmix recycling emerged, many still in an early stage of development, a few applied at industrial stage. So far, the companies taken hereby as case studies, are capable of abating Plasmix volumes for about 70%, although a combination of recycling pathways and techniques could eventually lead to fully close the recycling loop for plastics, reaching full accomplishment of circular economy
Advances in molecular genetics of dilated cardiomyopathy. The Heart Muscle Disease Study Group.
No full textIn clinical surveys, familial dilated cardiomyopathy (FDC) has been demonstrated in 20\% to 30\% of patients. In these patients, the cause of the disease lies at the DNA level. Molecular genetic studies represent the tools for the understanding of the etiology of FDC and are currently producing relevant advances: 6 different loci have been mapped so far. The only known disease gene is the dystrophin gene causing X-linked dilated cardiomyopathy, but other cytoskeletal proteins, such as adhalin, could be involved. In familial right ventricular cardiomyopathy (or arrhythmogenic right ventricular dysplasia) characterized by isolated or prevalent right ventricular involvement, three further disease loci have been identified
Atomic force microscopy of 3T3 and SW-13 cell lines: an investigation of cell elasticity changes due to fixation
No full textMechanical properties of single cells are of increasing interest both from a fundamental cell biological perspective and in the context of disease diagnostics. In this respect, atomic force microscopy (AFM) has become a powerful tool for imaging and assessing mechanical properties of biological samples. However, while these tests are typically carried out on chemically fixed cells, the most important data is that on living cells. The present study applies AFM technique to assess the Young’s modulus of two cells lines: mouse embryonic fibroblasts (NIH/3T3) and human epithelial cancer cells (SW-13). Both living cells and those fixed with paraformaldehyde were investigated. This analysis quantifies the difference between Young’s modulus for these two conditions and provides a coefficient to relate them. Knowing the relation between Young modulus of living and fixed cells, allows carrying out and comparing data obtained during steady-state measurements on fixed cells that are more frequently available in the clinical and research settings and simpler to maintain and probe
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
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