1,721,011 research outputs found
NPR-B, the C-type natriuretic peptide specific receptor, is the predominant biological receptor in mouse and pig myocardial tissue.
No full textAIM:The increased myocardial production and the elevated plasma concentrations of C-type natriuretic peptide (CNP) in heart failure patients suggest its involvement in pathophysiological cardiac remodeling. The cardiovascular action of CNP seems to be mainly mediated by natriuretic peptide receptor (NPR)-B but the importance of CNP/NPR-B signaling in heart is not yet well characterized. The aim of this study was to assess the cardiac mRNA expression of CNP and NPR-B together with those of BNP and NPR-A in order to evaluate the relative importance of these peptides and of their receptors in cardiovascular system.
METHODS:
The expression of mRNA coding for CNP, NPR-B, BNP and NPR-A was investigated in myocardial tissue (BALB/c mice, N=5) by use of RT-PCR. NPR-A and NPR-B expression were also evaluated in left ventricle of male adult minipigs without (N=5) and with pacing-induced heart failure (HF, N=5).
RESULTS:
The proposed method allowed to detect the expression of mRNA coding for CNP and NPR-B in myocardial tissue confirming the presence of these effectors in the heart. These data also indicate that CNP mRNA expression is lower with respect to that of BNP (CNP/GAPDH= 0.117+/-0.035 vs. BNP/GAPDH=0.247+/-0.066) and that NPR-B is the predominant subtype receptor in the heart (Mouse: NPR-A/GAPDH=0.244+/- 0.028; NPR-B/GAPDH=0.657+/-0.022; p=0.0008; Pig: NPR-A/GAPDH=3.06+/-1.75, NPR-B/GAPDH= 14.3+/-3.6, p=0.0028; HF Pig: NPR-A/GAPDH= 4.29+/-0.93, NPR-B/GAPDH=7.9+/-1.1, p=0.0043).
CONCLUSION:
In the present study, we provided the first evidence of a higher mRNA expression in cardiac tissue of NPR-B with respect to NPR-A indicating that CNP specific receptor (NPR-B) is the predominant biological receptor in mouse and pig myocardial tissue
Expression of C-type natriuretic peptide and of its receptor NPR-B in normal and failing heart.
No full textC-type natriuretic peptide (CNP) was recently found in the myocardium, but possible insights into differences between atrium and ventricle production are so far lacking. Our aim was to evaluate, in an experimental model of pacing-induced heart failure (HF), plasma and tissue levels of CNP and mRNA expression of the peptide and of its specific receptor, NPR-B. Cardiac tissue was collected from male adult minipigs without (control, n=5) and with pacing-induced HF (n=5). Blood samples were collected at baseline and after pacing (10 min, 1, 2, 3 weeks). CNP in plasma and in cardiac extracts was determined by a radioimmunoassay, while the expression of mRNA by real time PCR. Compared to control, plasma CNP was increased after 1 week of pacing stress (36.9+/-10.4 pg/ml vs.16.7+/-1.1, p=0.013, mean+/-S.E.M.). As to myocardial extract, at baseline, CNP was found in all cardiac chambers and its content was 10-fold higher in atria than in ventricles (RA: 13.7+/-1.9 pg/mg protein; LA: 8.7+/-3.8; RV: 1.07+/-0.33; LV: 0.93+/-0.17). At 3 weeks of pacing, myocardial levels of CNP in left ventricle were higher than in controls (15.8+/-9.9 pg/mg protein vs. 0.9+/-0.17, p=0.01). CNP gene expression was observed in controls and at 3 weeks of pacing. NPR-B gene expression was found in all cardiac regions analyzed, and a down-regulation was observed in ventricles after HF. The co-localization of the CNP system and NPR-B suggests a possible role of CNP in HF and may prompt novel therapeutical strategies
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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