1,720,970 research outputs found
Tramadol anti-inflammatory activity is not related to a direct inhibitory action on prostaglandin endoperoxide synthases
No full textThe analgesic drug tramadol has been shown to relieve pain in inflammatory conditions, to inhibit the development of experimental inflammation, and to reduce prostaglandin (PG)E 2 concentrations in the inflammatory exudate. In this study, we evaluated the putative activity of tramadol to suppress prostaglandin endoperoxide synthase-1 (PGHS-1), and prostaglandin endoperoxide synthase-2 (PGHS-2) activities in human whole blood in vitro. Platelet thromboxane (Tx)B 2 production and monocyte PGE 2 production in LPS-stimulated blood were measured in samples incubated with different concentrations (300 ng/ml, 3 μg/ml, 30 μg/ml) of tramadol or its enantiomers. Neither tramadol nor the enantiomers inhibited the formation of arachidonic acid metabolites. Our results indicate that the anti-inflammatory effect of tramadol demonstrated in some models is not related to a direct inhibitory effect on the formation of prostanoids
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
Evaluation of the effects of anti-thromboxane agents in platelet-vessel wall interaction
No full textWe evaluated the capacity of anti-aggregating agents to influence thromboxane A2 and prostacyclin formation, arachidonic acid-endoperoxide redirection, platelet aggregation and vessel tone, in isolated rabbit aorta incubated with homologous platelets. Picotamide (N,N′bis(3-pyridinylmethyl)-4-methoxy-isophthalamide), the only dual thromboxane A2-synthase inhibitor/receptor antagonist in clinical use, inhibited arachidonic acid-induced platelet aggregation with low potency, increased 180-fold by aorta presence. It inhibited thromboxane A2 formation in platelets and, in aorta presence, increased prostacyclin formation. Ozagrel (OKY-046, (E)-3-(4-(1-imidazolylmethyl)phenyl)-2-propenoic acid), a pure thromboxane A2-synthase inhibitor, behaved similarly to picotamide, although the aorta caused a higher (600-fold) shift. The potency of the antagonist SQ 29,548 (1S-(1α,2β(5Z),3β,4α))-7-(3((2-((phenylamino)carbonyl)hydrazino)methyl)-7-oxabicyclo(2.2.1)hept-2-yl)-5-heptenoic acid) was unaffected by aorta. In coincubation experiments, arachidonic acid-challenge increased thromboxane A2-dependent vessel tone; picotamide increased prostacyclin and reduced thromboxane A2 formation and vasoconstriction. Ozagrel mimicked picotamide; aspirin (acetylsalicylic acid) reduced aorta contractility, thromboxane A2 and prostacyclin formation. SQ 29,548 reduced vasoconstriction without affecting eicosanoids. We demonstrate the importance of redirection of eicosanoids in the mechanism of action of thromboxane A2 inhibitors/antagonists within platelet–vascular wall interactions. These findings bear relevance in the development of novel anti-thrombotic drugs
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
Vascular fibrosis in stroke-prone rats (SHRSP) is prevented by drugs active on inflammatory pathways
No full textBiochemical and mechanical properties of intraluminal thrombus from human abdominal aortic aneurysm
No full textDistinct roles for PAR1- and PAR2-mediated vasomotor modulation in human arterial and venous conduits
No full textBACKGROUND: Patency rates after coronary artery bypass grafting (CABG) are better if the internal mammary artery (IMA) is used rather than the greater saphenous vein (GSV), and may be related to the endothelial release of vasodilators antagonizing vascular contraction. It has recently been shown that a family of protease-activated receptors (PARs) modulate endothelium-dependent vasodilatation. OBJECTIVE AND METHODS: The aim of this study was to evaluate the presence and functional role of protease-activated receptor 1 (PAR1) and protease-activated receptor 2 (PAR2) in mediating vascular tone in IMAs and GSVs from patients undergoing CABG by means of real time-PCR and isometric tension measurements. RESULTS: PAR1 mRNA levels were higher than those of PAR2 mRNA in both vessels. A selective PAR2-activating peptide (PAR2-AP), SLIGKV-NH(2) (0.01-100 micromol L(-1)), failed to induce vasorelaxation in precontracted IMA and GSV rings, whereas the selective PAR1-AP, TFLLR-NH(2) (0.001 to 10 micromol L(-1)), caused greater endothelium-dependent relaxation in the IMAs (pD(2) values 7.25 +/- 0.6 vs. 7.86 +/- 0.42, P < 0.05; E(max) values 56.2 +/- 17.3% vs. 29.7 +/- 13.4%, P < 0.001). Preincubation with TNFalpha (3 nmol L(-1)) induced vasorelaxation in IMAs in response to PAR2-AP (P < 0.05 vs. non-stimulated vessels); the response to PAR1-AP was unchanged. The relaxation induced by both PAR-APs was NO- and endothelium-dependent. CONCLUSION: These data show that functionally active PAR1 and PAR2 are present in IMAs and GSVs, and that inflammatory stimuli selectively enhance endothelium-dependent relaxation to PAR2-AP in IMAs
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