1,720,965 research outputs found
Epigenetic regulation of myocardial homeostasis, self-regeneration and senescence
No full textThe adult myocardium has limited capacity to preserve, renew or rejuvenate itself. The local microenvironment may induce epigenetic changes affecting the survival, proliferation, function and senescence of cardiac cells at rest and following the exposure to different stressors. The cellular response to microenvironment is characterized by the release of ions, oxygen free radicals, auto/paracrine factors and RNAs that drive the magnitude of gene reprogramming through the interaction with specific promoters. The epigenetic alterations may act at transcriptional and post-transcriptional level and change cardiac physiological traits. The abnormal DNA methylation underlies the progressive decay of contractile function and the angiogenic ability; while, the histone acetylation promotes the survival, function and proliferation of cardiac cells in the presence of ischemic microenvironment. At least, the expression and secretion of microRNAs and long noncoding RNAs may regulate the threshold to stress tolerance of adult cardiac cells and induce the matrix turnover as well. Natural or synthetic active compounds effectively modulate the epigenetic state of cardiac cells. Plant foods contain many active compounds with epigenetic properties and might assume a clinical significance as natural cardiac regenerators or rejuvenators. Our review describes novel epigenetic mechanisms that underpin myocardial remodeling, repair/ regeneration or senescence in order to support the development of most effective and reproducible rescue therapy of adult heart
Exosomes released from sulforaphane-treated fibroblasts protect the cardiomyocytes from angiotensin II-induced hypertrophy
No full textIntroduction: The communication between fibroblasts and cardiomyocytes underlies the pathological cardiac hypertrophy induced by angiotensin-II (AngII), which contributes to heart failure. Fibroblast-derived exosomes (F-Exo) have been implicated in mediating AngII-induced cardiomyocyte hypertrophy. However, how release of anti-hypertrophic F-Exo is induced, remains an unanswered issue. Sulforaphane (SFN), a naturally occurring isothiocyanate extracted from cruciferous vegetables, attenuates AngII-induced cardiomyocytes hypertrophy. We tested the effects of SFN on the release of anti-hypertrophic F-Exo in vitro. Methods: Murine embryo fibroblasts were treated with non-toxic dose of SFN (3 μM/7 days). Intact F-Exo were isolated from cell culture media by differential centrifugation. F-Exo were quantified by Western blot using CD63. Hypertrophy of HL-1 cardiomyocytes was induced by AngII (100 nM/12 h). Cell viability was assessed by MTT assay. Cell surface area, an indicator of cell hypertrophy, was measured after 3 or 24 h incubation with 30 μg exosomes isolated from SFN-treated (SFN-F-Exo) or untreated (F-Exo, control) fibroblasts. Uptake by HL-1 of DiA-labeled exosomes was measured under rest or AngII. Exosomal content of Maspin, a protease inhibitor with function of inhibitor of histone deacetylase 1, was assessed by Western blot. Results: Treatment with F-Exo significantly increased HL-1 viability by 53% under stress compared to control. Stressed HL-1 treated for 24 h with SFN-F-Exo displayed cell surface area similar to resting cells, but not those treated with F-Exo. Stressed HL-1 exhibited a ~3-fold increase in SFN-F-Exo uptake rather than F-Exo. SFN-F-Exo are enriched in Maspin. Summary/conclusion: SFN increases the uptake of F-Exo which display the ability to prevent AngII-induced cardiomyocytes hypertrophy. Higher content of Maspin in SFN-F-Exo suggests that modulation of exosomal uptake and hypertrophy in stressed cardiomyocytes may be epigenetically driven
Dual, constrictor-to-dilator, response of the mouse ductus arteriosus to the microsomal prostaglandin E synthase-1 inhibitor, 2-(6-chloro-1H-phenanthro[9,10d]imidazol-2-yl)isophthalonitrile.
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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
Valutazione delle prestazioni analitiche di un nuovo metodo per il dosaggio dell'aldosterone
No full textIn questi ultimi anni sono stati sviluppati kit commerciali per il dosaggio dell’aldosterone utilizzabili su piattaforme automatizzate. Lo scopo del presente studio è stato valutare le caratteristiche analitiche ed i risultati clinici ottenuti con un nuovo metodo di misura dell’aldosterone che si avvale della piattaforma automatizzata LIAISON (DiaSorin, Saluggia – VC) e confrontare i valori di aldosterone misurati con questo nuovo metodo con quelli ottenuti, sugli stessi campioni, con il metodo RIA ALDO-CTK (DiaSorin, Saluggia - VC), con il metodo automatizzato che utilizza la piattaforma iSYS (IDS, Boldon, UK - distributore italiano: Pantec srl, Torino) e con la spettrometria di massa (metodica Perkin-Elmer). Sono stati anche misurati con questo nuovo metodo 5 campioni di controllo, distribuiti nella VEQ Immunocheck (QualiMedLab srl, Pisa) e i valori trovati sono stati confrontati con quelli ottenuti con la media di consenso dei laboratori partecipanti.
A questo scopo sono stati reclutati 147 soggetti apparentemente sani e 199 pazienti con malattie cardiovascolari.
Il metodo di dosaggio dell’aldosterone che utilizza la piattaforma automatizzata LIAISON presenta valori di LoB e LoD rispettivamente di 18 pg/mL e 30 pg/mL; mentre i valori di LoQ al 10% CV e al 20% CV corrispondono a concentrazioni di aldosterone pari a 95 pg/mL e 40 pg/mL, rispettivamente. Il metodo automatizzato LIAISON presenta una migliore praticabilità sperimentale rispetto al metodo RIA; in particolare il tempo di analisi è inferiore ad un’ora per il metodo automatizzato, mentre con il metodo RIA occorrono circa 18-24 ore. Infine, il metodo LIAISON presenta risultati clinici che sono confrontabili con quelli ottenuti con il metodo automatizzato che utilizza la piattaforma iSYS (R=0,906, N=294), con quelli della spettrometria di massa (R=0,746, N=30), e con i valori ottenuti in 5 campioni di controllo della VEQ Immunocheck (R=0,936, p= 0,0191). In conclusione, il metodo di dosaggio dell’aldosterone che utilizza la piattaforma automatizzata LIAISON sembra essere preferibile ai metodi manuali RIA ed EIA, soprattutto in quei laboratori, che già utilizzano la piattaforma LIAISON per il dosaggio di altri analiti e che devono eseguire il dosaggio di questo ormone in pochi campioni ogni giorno, ed inoltre fornire al clinico una risposta in tempi brevi
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
Detection of mtDNA with 4977 bp deletion in blood cells and atherosclerotic lesions of patients with coronary artery disease.
No full textDispelling 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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