1,721,128 research outputs found
Human Ghrelin: A Gastric Hormone with Cardiovascular Properties
No full textGhrelin is a growth hormone-releasing peptide, isolated from the stomach. Researches in progress documented that ghrelin participates in the stimulation of the hypothalamus-pituitary-adrenal axis at the hypothalamic level and in the regulation of energy balance. Growth hormone-independent functions have been ascribed to ghrelin. Among others, a large body of literature demonstrated the presence of specific receptors for ghrelin, distributed at the level of cardiomyocytes and endothelial cells. Therefore, a link between ghrelin and cardiovascular system has been hypothesized and, then, demonstrated in both experimental and clinical studies. Ghrelin has largely documented cardiac beneficial effects, including protection from ischemia/reperfusion injury, attenuation of left ventricular remodeling following myocardial infarction, and improvement of left ventricular function. Exercise level in patients with chronic heart failure had also been seen. Ghrelin exerts these effects through several mechanisms, including the inhibition of apoptosis. At the level of blood vessels, ghrelin exerts a significant impact on vascular function. In particular, acutely infused, ghrelin reverses endothelial dysfunction by increasing NO availability and restores the endothelin-1/nitric oxide imbalance in the peripheral microcirculation of patients with metabolic syndrome. Antioxidant/anti-inflammatory effects, and-or an ameliorated insulin sensitivity are proposed mechanisms whereby ghrelin exerts its vascular protective actions. At higher doses, ghrelin also decreases blood pressure, by mechanisms that involve the modulation of sympathetic nervous system. This finding highlights the ghrelin system as a promising candidate for cardiovascular drug discovery
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
Predictors of Major Adverse Cardiovascular Events in Follow-Up of Patients Undergoing Carotid Endarterectomy: The MCAT (Mayo Clinic Carotid Artery Atherosclerosis Trial) Study
No full textBackground
Atherosclerotic carotid artery disease may be associated with a high risk of Major Adverse Cardiovascular Events (MACE). We aimed to assess the rate of MACE and possible predictors of events after carotid endarterectomy (CEA). We hypothesized that cardiovascular risk factors are not predictive of MACE and that MACE may be related to plaque’s features such as intraplaque hemorrhage (IPH). We also aimed to determine whether IPH is associated with an inflammatory shift of the plaque environment by assessing the levels of inflammatory cytokines and mapping the immune cell microenvironment.
Methods
We enrolled patients undergoing CEA. The primary outcome was the rate of overall MACE including cardiac events, cerebrovascular accidents (CVA), and all-cause mortality. Univariate and multivariable analysis were performed to identify predictors of overall MACE and each endpoint separately. Furthermore, we compared the standardized mortality ratio (SMR) of our population with the SMR of the age-sex-matched Minnesota population. Cytokines levels in atherosclerotic plaque tissue were obtained using multiplex ELISA and Imaging Mass Cytometry (IMC) was used to define the site-specific immune cell microenvironment in CEA specimens.
Results
A total of 710 patients were followed for a median of 7.1 [2.9-11.9] years after CEA. MACE occurred in 442 (62.3%) patients: all-cause mortality (N=198, 27.0%), cardiac events (N=169, 23.1%), and CVA (N=75,10.2%). In the multivariable models, history of cardiac events was predictive of overall MACE (HR 2.09 [95%CI 1.34-3.27]; p=0.001), age was an independent predictor of all-cause mortality (HR 1.02 [95%CI 1.00-1.04]; p=0.023), and only a history of cardiac events was predictive of future cardiac events (HR 1.75 [95%CI 1.30-2.37]; p<0.001).The SMR was significantly higher at 10-year and 21-year follow-up than the Minnesota population. In plaques with IPH vs. those without IPH, the levels of cytokines such as MCP-1, IL6, IL8, and TNFalpha were significantly higher and immune cells and immune checkpoints were more expressed.
Conclusions
Patients with carotid artery disease have a high rate of MACE following CEA, which is not predicted by most of the conventional cardiovascular risk factors. In response, we propose a paradigm shift, speculating that carotid plaque characteristics may provide further insight into the risk stratification of this patient population in addition to clinical risk factors
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
DHJ910279 Supplemental Material - Supplemental material for A digital health weight-loss intervention in severe obesity
No full textSupplemental material, DHJ910279 Supplemental Material for A digital health weight-loss intervention in severe obesity by Conor Senecal, Maria Collazo-Clavell, Beth R Larrabee, Mariza de Andrade, Weihua Lin, Bing Chen, Lilach O. Lerman, Amir Lerman and Francisco Lopez-Jimenez in Digital Health</p
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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