1,721,066 research outputs found
Adiponectin stimulates production of nitric oxide in endothelial cells through AMPK-dependent phosphorylation of eNOS at Ser(1179) RID B-1970-2008
No full textAdiponectin stimulates production of nitric oxide in vascular endothelial cells RID B-1970-2008
No full textAdiponectin is secreted by adipose cells and mimics
many metabolic actions of insulin. However, mechanisms
by which adiponectin acts are poorly understood.
The vascular action of insulin to stimulate endothelial
production of nitric oxide (NO), leading to vasodilation
and increased blood flow is an important component of
insulin-stimulated whole body glucose utilization.
Therefore, we hypothesized that adiponectin may also
stimulate production of NO in endothelium. Bovine aortic
endothelial cells in primary culture loaded with the
NO-specific fluorescent dye 4,5-diaminofluorescein diacetate
(DAF-2 DA) were treated with lysophosphatidic
acid (LPA) (a calcium-releasing agonist) or adiponectin
(10 g/ml bacterially produced full-length adiponectin).
LPA treatment increased production of NO by 4-fold.
Interestingly, adiponectin treatment significantly increased
production of NO by 3-fold. Preincubation of
cells with wortmannin (phosphatidylinositol 3-kinase
inhibitor) blocked only adiponectin- but not LPA-mediated
production of NO. Using phospho-specific antibodies,
we observed that either adiponectin or insulin treatment
(but not LPA treatment) caused phosphorylation
of both Akt at Ser473 and endothelial nitric-oxide synthase
(eNOS) at Ser1179 that was inhibitable by wortmannin.
We next transfected bovine aortic endothelial
cells with dominant-inhibitory mutants of Akt (Akt-
AAA) or AMP-activated protein kinase (AMPK) (AMPKK45R).
Neither mutant affected production of NO in response
to LPA treatment. Importantly, only AMPKK45R,
but not Akt-AAA, caused a significant partial
inhibition of NO production in response to adiponectin.
Moreover, AMPK-K45R inhibited phosphorylation of
eNOS at Ser1179 in response to adiponectin but not in
response to insulin. We conclude that adiponectin has
novel vascular actions to directly stimulate production
of NO in endothelial cells using phosphatidylinositol
3-kinase-dependent pathways involving phosphorylation
of eNOS at Ser1179 by AMPK. Thus, the effects of
adiponectin to augment metabolic actions of insulin in vivo may be due, in part, to vasodilator actions of
adiponectin
Adiponectin stimulates production of nitric oxide in endothelial cells trough AMPK-dependent phosphorylation of eNOS at Ser1179
No full text
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
Adiponectin directly stimulates production of nitric oxide in endothelial cells via a PI 3-K-dependent pathway
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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