1,720,962 research outputs found
Protocol to generate an in vitro model to study vascular calcification using human endothelial and smooth muscle cells
Full text linkVascular calcification is a systemic disease characterized by calcium salt deposition
within vascular walls. Here, we present a protocol for establishing an
advanced dynamic in vitro co-culture system using endothelial and smooth muscle
cells to replicate vascular tissue complexity. We describe steps for cell culture
and seeding in a double-flow bioreactor that recreates the action of blood in humans.
We then detail the induction of calcification, setting up of the bioreactor,
followed by cell viability assessment and calcium quantification
Vascular Calcification: In Vitro Models under the Magnifying Glass.
No full textVascular calcification is a systemic disease contributing to cardiovascular morbidity and mortality. The pathophysiology of vascular calcification involves calcium salt deposition by vascular smooth muscle cells that exhibit an osteoblast-like phenotype. Multiple conditions drive the phenotypic switch and calcium deposition in the vascular wall; however, the exact molecular mechanisms and the connection between vascular smooth muscle cells and other cell types are not fully elucidated. In this hazy landscape, effective treatment options are lacking. Due to the pathophysiological complexity, several research models are available to evaluate different aspects of the calcification process. This review gives an overview of the in vitro cell models used so far to study the molecular processes underlying vascular calcification. In addition, relevant natural and synthetic compounds that exerted anticalcifying properties in in vitro systems are discussed
Novel in vitro evidence on the beneficial effect of quercetin treatment in vascular calcification.
No full textVascular calcification is a pathological chronic condition characterized by calcium
crystal deposition in the vessel wall and is a recurring event in atherosclerosis,
chronic kidney disease, and diabetes. The lack of effective therapeutic treatments
opened the research to natural products, which have shown promising potential in
inhibiting the pathological process in different experimental models. This study
investigated the anti-calcifying effects of Quercetin and Berberine extracts on
vascular smooth muscle cells (VSMCs) treated with an inorganic phosphate
solution for 7 days. Quercetin has shown the highest anti-calcifying activity, as
revealed by the intracellular quantitative assay and morphological analysis.
Confocal microscopy revealed downregulation of RUNX2, a key marker for
calcified phenotype, which was otherwise upregulated in calcified VSMCs. To
investigate the anti-inflammatory activity of Quercetin, culture media were
subjected to immunometric assays to quantify the levels of IL-6 and TNF-α, and
the caspase-1 activity. As expected, calcified VSMCs released a large quantity of
inflammatory mediators, significantly decreasing in the presence of Quercetin. In
summary, our findings suggest that Quercetin counteracted calcification by
attenuating the VSMC pathological phenotypic switch and reducing the
inflammatory response. In our opinion, these preliminary in vitro findings could
be the starting point for further investigations into the beneficial effects of
Quercetin dietary supplementation against vascular calcification
Cardiac tissue engineering: Multiple approaches and potential applications
No full textThe overall increase in cardiovascular diseases and, specifically, the ever-rising exposure to cardiotoxic compounds has greatly increased in vivo animal testing; however, mainly due to ethical concerns related to experimental animal models, there is a strong interest in new in vitro models focused on the human heart. In recent years, human pluripotent stem cells-derived cardiomyocytes (hiPSC-CMs) emerged as reference cell systems for cardiac studies due to their biological similarity to primary CMs, the flexibility in cell culture protocols, and the capability to be amplified several times. Furthermore, the ability to be genetically reprogrammed makes patient-derived hiPSCs, a source for studies on personalized medicine. In this mini-review, the different models used for in vitro cardiac studies will be described, and their pros and cons analyzed to help researchers choose the best fitting model for their studies. Particular attention will be paid to hiPSC-CMs and three-dimensional (3D) systems since they can mimic the cytoarchitecture of the human heart, reproducing its morphological, biochemical, and mechanical features. The advantages of 3D in vitro heart models compared to traditional 2D cell cultures will be discussed, and the differences between scaffold-free and scaffold-based systems will also be spotlighte
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
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