1,720,956 research outputs found
In vivo characterization of B-2 receptors mediating hypotension in anesthetized rabbits and guinea pigs
No full textWith the discovery of suitable pharmacologic tools
for B 2 receptor characterization, it has been demonstrated in vitro that the pharmacological spectrum of
this receptor type obtained in various organs (e.g.
intestine, vessels, urogenital tract) remains the same
within the species but may show marked differences
among species (e.g. the rabbit, the guinea pig) (Regoli et al., 1993; Regoli et al., 1994). Thus, orders of
potency of agonists in rabbit and guinea pig tissues
are opposite in that [Hyp3]BK is approximately 50-
100 times more potent than [AibT]BK in the rabbit
and inversely, the latter compound is 2-10 times
more active than [Hyp3]BK in the guinea pig. Furthermore, competitive antagonists, such as DArg[Hyp3,d-PheV,LeuS]BK and WIN 64338 (a nonpeptide compound), have also shown differences in
their ability to block bradykinin responses in these
two species while HOE 140, a non-competitive and
long-acting antagonist, shows equipotent activities
on both. Based on these results, we have suggested
that B 2 receptors may be pharmacologically subject
to interspecies variability. The present study was
designed to find out if results obtained in vitro can
be reproduced in vivo by measuring pharmacological
parameters (namely EDs0 for agonists and ICso for antagonists) on kinin-induced blood pressure changes
in the rabbit and the guinea pig
Kinin receptors in the diabetic mouse
No full textIt has been proposed that kinins are important inflammatory mediators involved in the pathogenesis of several diseases. In the present study, we attempted to determine the effects of kinins in a type I diabetic mouse model, using in vitro assays. Injection of streptozotocin (STZ) to the C57BL/Ks mdb mice causes an insulitis (inflammation of Langerhans islets) that leads to the diabetic condition. Ten days following the STZ treatment, the mice showed increased glycemia. We examined the effect of kinins and other agents (substance P, neurokinin A, acetylcholine) on the stomach fundus and urinary bladder of control and diabetic mice. Our results show that the sensitivity of the stomach fundus to bradykinin (BK) and desArg9BK (DBK), but not to other contractile agents, was substantially increased in the tissues of diabetic mice. The maximal contractions induced by BK and DBK were increased 1.5- to 2-fold in the stomachs from diabetic mice compared with those from normal mice. BK induced similar maximal contractions of urinary bladder strips from normal or STZ-treated mice, while DBK did not show any effect on this preparation. Interestingly, the apparent affinities of all agonists are similar in the two groups, normal and diabetic. These results suggest that B, and B, receptors are overexpressed in the stomach fundus but not in the urinary bladder of diabetic mice
[Nphe(1)]nociceptin-(1-13)NH2 selectively antagonizes nociceptin effects in the rabbit isolated ileum
No full textWhen suspended in vitro in isolated organ baths, segments of the rabbit ileum show a fairly strong and stable spontaneous activity,
which derives from the continuous release of acetylcholine and the activation of muscarinic receptors, since the activity is completely
eliminated by atropine. Dynorphin A pEC50: 8.6"0.07., neuropeptide Y and its congener human pancreatic polypeptide pEC50:
9.40"0.10., and nociceptin pEC50: 8.08"0.12. dose-dependently inhibit the spontaneous activity through the activation of receptors,
which are specifically antagonised respectively by naloxone p A2: 7.17"0.12., 2-naphtalen-1-ylamino.-3-phenylpropionitrile JCF 104;
p A2: 5.80"0.10., and wNphe1xnociceptin-1–13.NH2 p A2: 6.17"0.19.. This last compound, a selective nociceptin-receptor OP4.
antagonist, inhibits the effect of nociceptin in a competitive manner, as demonstrated by Schild analysis. wNphe1xnociceptin-1–13.NH2
also antagonizes the effects of other OP4 receptor ligands such as the full agonist, nociceptin-1–13.-NH2, and the partial agonists,
wPhe1cCH2–NH.Gly 2 xnociceptin-1–13.-NH2 intrinsic activity a E.s0.5. and Ac-RYYWK-NH2 a Es0.5., with p A2 values
ranged from 5.8 to 6.2. These results indicate that the functional site mediating the inhibitory effect of nociceptin in the rabbit ileum, is
pharmacologically identical to the OP4 sites of other species mouse, rat, guinea pig, man., since the potencies p A2 values. of the pure
and competitive antagonist wNphe1xnociceptin-1–13.NH2 is very similar to the values obtained in the other species. Moreover, the rabbit
ileum is one of the few isolated organs that allow classifying compounds, which interact with OP4 receptors as full agonists, partial
agonists, or pure antagonists
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
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