1,720,985 research outputs found
Cimetropium bromide, a new antispasmodic compound: a review of the preclinical pharmacology.
No full textAntisecretory and antiulcer effect of the H2-receptor antagonist famotidine in the rat: comparison with ranitidine.
No full text1 The effects of the new H2-receptor antagonist famotidine, administered orally, on gastric secretion and emptying as well as on experimentally-induced gastric and duodenal ulcers were studied in the rat. Ranitidine was used as a reference compound. 2 Both compounds inhibited acid secretion in a dose-dependent manner. Calculated ED50 values were 0.80 and 6.84 mg kg-1 for famotidine and ranitidine, respectively. However, the duration of the antisecretory action was the same for both drugs. 3 The effect of the two drugs, administered at equiactive antisecretory doses, on gastric emptying was different. Ranitidine significantly accelerated the emptying rate whereas famotidine had no effect. 4 Famotidine reduced, in a dose-dependent manner, ulcer incidence in stomachs of dimaprit-treated rats and in duodena of cysteamine-treated animals with a potency respectively 2 and 7 times higher than that of ranitidine. 5 Famotidine is therefore an effective antisecretory and untiulcer compound. Its potency, but not its efficacy, is higher than that of ranitidine. Moreover, the duration of the antisecretory action is virtually the same for both drugs
Effect of cimetropium bromide and other antispasmodic compounds on in vitro guinea-pig gallbladder.
No full textThe effect of cimetropium bromide, a new antimuscarinic compound, on bethanechol- and electrically-induced contractions was studied on isolated guinea-pig gallbladder. Atropine and two other widely employed antispasmodics (i.e., rociverine and octylonium bromide) were employed as reference compounds. Cimetropium and atropine proved to be competitive antimuscarinics, their pA2 being 7.77 +/- 0.14 and 8.31 +/- 0.14, respectively. On the contrary, rociverine displayed a dual effect being a competitive antagonist at low (up to 10(-5) mol/l) and a mixed one at high (greater than 10(-5) mol/l) concentrations. When tested against bethanechol- and electrically-induced contractions, all the compounds, with the exception of octylonium bromide, showed a concentration-dependent relaxant effect. In both experimental conditions, the potency of cimetropium was of the same order of magnitude as that of atropine and 150-200 times higher than that of rociverine. These data, together with the reported activity on human gallbladder in vivo and the well known involvement of cholinergic system in the control of gallbladder motility, could represent the rationale for the clinical use of cimetropium in the treatment of biliary colics as well as spasms of biliary tree
Inhibition of gastric acid secretion by adenosine receptor stimulation in the rat.
No full textThe effects of adenosine and its metabolically stable derivative L-phenylisopropyladenosine (L-PIA), acting mainly on A1 receptors, on gastric acid secretion were studied in the rat. Although inactive by intraduodenal route, subcutaneous adenosine significantly inhibited acid secretion. This inhibition, however, was not dose-dependent. On the contrary, L-PIA was able to decrease dose-dependently acid output by both subcutaneous and intraduodenal route, its ED50 being 0.11 mg/kg subcutaneously and 0.24 mg/kg intraduodenally. The inhibitory effect of L-PIA was reduced by prior administration of theophylline. These results suggest that activation of A1-receptors inhibits acid secretion in the rat
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
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