1,720,962 research outputs found
1,4-Dihydropyridine activators in the tiamdipine series.
No full textThe pharmacologic and radioligand binding properties of 5-nitro analogs of the 1,4-dihydropyridine Ca2+ channel antagonist, tiamdipine (2-(2-aminoethylthio)methyl-3-carbomethoxy-5-carbomethoxy-6-m ethyl-4-(3-nitrophenyl)-1,4-dihydropyridine) and its N-formyl derivative have been measured in rat tail artery, guinea pig ileum and rat heart. The enantiomers of both analogs showed activator and antagonist properties, the latter being exhibited at lower concentrations
Influence of high sodium intake on urinary calcium excretion and cardiac calcium channels in spontaneously hypertensive rats.
No full textDietary sodium intake: influence on calcium channels and urinary calcium excretion in spontaneously hypertensive rats.
No full textBinding of the 1,4-dihydropyridine [3H]PN200 110 was employed as an index of cardiac Ca2+ channels in normotensive (WKY) and spontaneously hypertensive (SHR) rats during 4 weeks of normal (0.73% NaCl) and high (8% NaCl) sodium diets when the rats were between 20 and 24 weeks of age. Binding site density was not different at the beginning of the study but was increased significantly (P less than 0.01) after 1 week in the SHR on a high sodium diet; this difference was not apparent at 2, 3 or 4 weeks of the diet. During this same period, the urinary Ca2+ excretion in SHR was enhanced significantly (P less than 0.01) and the urinary calcium/sodium ratio was elevated during the high sodium intake period
Interactions of analogs of the 1,4-dihydropyridine tiamdipine in cardiac and smooth muscle.
No full textTwo series of 1,4-dihydropyridines related to tiamdipine, 2-(2-aminoethylthio)methyl-3-carboethoxy-5-carbomethoxy-6- methyl-4-(3-nitrophenyl)-1,4-dihydropyridine, have been evaluated for their pharmacologic and radioligand binding properties in smooth and cardiac muscle. In the tiamdipine series the influence of phenyl ring substitution, 3-Cl, 3-MeO and 3-CF3, was greatly reduced relative to the N-formyl and neutral nifedipine derivatives. Consistent with our previous observations onset and offset of action were greatly reduced by the presence of the amine side chain. In tiamdipine analogs also bearing an asymmetric substituent at C-2, chirality at C-4 was determinant for activity
Age related changes in Ca2+ channels in spontaneously hypertensive rats.
No full textThe binding of the Ca2+ channel antagonist [3H]PN200 110 to 1,4-dihydropyridine binding sites in cardiac, brain and vascular smooth muscle preparations from WKY and SHR was studied as a function of age and blood pressure. 2. Binding site density in the heart from prehypertensive SHR (6 weeks) was significantly lower than that of WKY. 3. Between 6 and 12 weeks binding site density in SHR increased and between 12 and 24 weeks there was no difference between WKY and SHR. No changes in affinity occurred. 4. In brain a significant fall in binding site density occurred between 6 and 12 weeks and there was (with limited data) an increase in binding site density in tail artery membranes. 5. A good correlation (r = 0.82) exists between blood pressure and cardiac binding site density between 6 and 12 weeks of age in SHR
Modelling and simulation of pharmacokinetic aspects of cytochrome P450-based metabolic drug-drug interactions
No full textModelling and simulation of pharmacokinetic aspects of cytochrome P450-based metabolic drug-drug interactions
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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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