1,720,962 research outputs found
Dual effects of a homeopathic mineral complex on the carrageenan-induced oedema in rats.
No full textA computer model of the "five elements" theory of traditional Chinese medicine.
No full textIn this article, a model is presented of a network whose structure was inspired by the 'five elements law' of Chinese medicine. Computer simulations illustrate the dynamic behavior of this system, that can be set in different attractors of Boolean type and can be differentially modified by delays and perturbations. We suggest that this model may contribute to the understanding of the 'logic' of the regulation of biological systems by means of small and carefully selected perturbations, a major line of thought of complementary therapies
Decrease of platelet intracellular pH and adhesion by ticlopidine in patients with vascular disease
No full textBACKGROUND: Ticlopidine inhibits platelet aggregation by preventing the binding of fibrinogen to its platelet receptor. We examined whether this inhibition involved platelet transduction system such as Na+/H+ pump and platelet intracellular calcium. METHODS: Platelet adhesion in 13 patients with peripheral vascular disease treated with ticlopidine, 250 mg b.i.d for 30 days, was measured in culture microplates before and after therapy. The microplate wells were coated with human plasma, fibrinogen or collagen, and platelet adhesion was studied in the resting condition and after stimulation with 1 and 10 microM ADP. At the same time, platelet intracellular calcium and ADP-induced calcium increases were measured with the fluorescent indicator Fura 2. In addition, intracellular pH and thrombin-induced pH variations were measured with the fluorescent probe BCECF. RESULTS: Platelet adhesion to plasma and fibrinogen was significantly reduced (about 50%) after treatment with ticlopidine, while adhesion to collagen was not modified. Basal calcium and ADP-induced calcium increase were not significantly different before and after ticlopidine. Platelet basal intracellular pH was reduced (from 7.44+/-0.009 to 7.41+/-0.017, p<0.05), but agonist-induced alkalinisation was not significantly different. Early acidification, not dependent on Na+/H+ exchange, was also reduced (p<0.05). CONCLUSIONS: These data do not seem to support the hypothesis that ticlopidine-induced reduction of platelet adhesion depends on alteration of the mechanisms determining signal transduction, at least as far as basal and post-stimulation intracellular calcium is concerned. On the contrary, the possibility that ticlopidine inhibits the Na+/H+ antiport remains open to consideration
Dual effects of formylpeptides on the adhesion of endotoxin-primed human neutrophils
No full textNeutrophils, treated with sequential additions of bacterial products such as endotoxin (E. Coli lipopolysaccharide, LPS) and the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP), undergo to metabolic activation and express membrane-anchoring proteins that promote adhesion to serum-coated culture wells. By investigating the dose-response relationships of these phenomena, we have found that: (a) resting neutrophils do not produce a significant amount of superoxide (O2-) and show only minimal adhesion to serum-coated plastic surfaces; (b) fully activatory doses (> 5 x 10(-8) M) of fMLP induce the release of O2- and a significant increase of the cell adhesion; (c) pretreatment of the cells for 1 h with LPS augments cell adhesion to serum-coated culture wells in the absence of further stimulation and primes the neutrophils to enhanced fMLP-dependent O2- release; (d) addition of low, substimulatory doses of fMLP (from 10(-10) M to 5 x 10(-9) M) inhibits and reverses the adhesion of LPS-treated cells, (e) high fMLP doses ( > 10(-7) M) are additive to LPS in promoting adhesion. Phorbol-myristate acetate (> 10(-9) M) increased adhesion in both normal and LPS-treated neutrophils, but low doses of this stimulant did not inhibit adhesion. Low doses (10(-9) M) of fMLP increased intracellular cyclic AMP in both normal and LPS-treated neutrophils, suggesting that stimulus-induced rises in cAMP may be the negative signal responsible for down-modulation of adhesion.(ABSTRACT TRUNCATED AT 250 WORDS
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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