1,720,967 research outputs found
Modulation of glial P2Y receptors by algogenic mediators in the trigeminal ganglion: a role for the purinergic system in the mechanism of action of known anti-migraine drugs?
No full textAim: to study the role of the purinergic system in the neuron-to-glial cell communication within the trigeminal ganglion (TG), and its cross-talk with known pro-algogenic systems (such as bradykinin, BK, calcitonin gene-related peptide, CGRP, and prostaglandins). The final goal is to identify new cellular and molecular players in the onset and maintenance of trigeminal-associated pain, for the development of innovative therapies for migraine.
Methods: primary mixed neuron-glia or purified glial cultures from mouse TG were used. G protein-coupled P2Y receptor function was evaluated by single cell calcium imaging; the extracellular concentrations of CGRP and PGE2 were measured by ELISA assays. Western blot experiments on P2Y1, P2Y2 and P2Y4 receptor subtypes were also performed. The effect of known analgesic drugs on P2Y receptor function and CGRP and PGE2 release was also tested.
Results: exposure of mixed-neuron glia cultures to BK induced the neuronal release of CGRP, which, in turn, significantly potentiated P2Y receptor-mediated calcium responses to their cognate ligands ADP and UTP on satellite glial cells. The anti-migraine drug sumatriptan completely inhibited both BK-mediated CGRP release, and the potentiation of P2Y receptors. Acetylsalicylic acid and ibuprofen also inhibited CGRP and PGE2 release from neurons, suggesting that prostaglandins are involved in the complex network of events leading to the potentiation of glial P2Y receptors. Single cell calcium imaging experiments by using selective and non-selective P2Y receptors antagonists suggested that CGRP exposure potentiates P2Y1 and P2Y2 receptor subtypes, as confirmed by western blot analysis. Methyl-β-cyclodextrin, which removes cholesterol from cultured cells and disrupts lipid rafts, significantly inhibits the increase in the [Ca2+]i and in the % of cells responding to the P2Y1 agonist ADP with no effects on UTP-mediated responses through the P2Y2 receptor subtype, suggesting the localization in membrane lipid rafts of P2Y1 receptors only.
Conclusions: our data suggest that a complex cross-talk between neuronal and glial cells takes place in the TG, involving pain mediators and extracellular nucleotides. Modulation of this network by known anti-migraine drugs, such as triptans and NSAIDs, suggests that it might play an important role in the development of migraine pain. Further studies are in progress to understand the pro- or anti-algogenic role of the different P2Y receptor subtypes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Rapeseed: an alternative crop for Idaho
No full textBulletin no. 752 Moscow, Idaho :University of Idaho, College of Agriculture, Agriculture Experiment Station, 1994-02-01. Author(s): Melfi, J. A.; Withers, Russell V
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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