Dante Miranda

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The osmolyte function of amino acids and Cl in native NIH/3T3 cells not expressing the P-glycoprotein was examined by investigating the free amino acid concentration and the swelling-activated efflux of [3H]taurine, as representative of amino acids, and of 125I, as a tracer for Cl. Taurine and 125I efflux was activated by 20 and 30% hyposmotic solutions. At(More)
Preincubation of peripheral blood lymphocytes (PBL) from drug-free, healthy volunteers with either the protein tyrosine kinase inhibitor genistein (GNT, n = 10, final concentration 200 microM) or the protein kinase A activator dybutiryl-cyclic-AMP (cAMP, n = 11, final concentration 10 microM), resulted in a significant inhibition of natural killer cell(More)
Nucleotides in the intestinal lumen may decrease the inflammatory response to ischemia-reperfusion. In a newborn-swine model, we showed that perfusion of the intestinal lumen with nucleotides in concentrations similar to those in human milk induced hyperemia. The levels of hypoxanthine (and xanthine) were not increased in the presence of nucleotides during(More)
We studied the effect of methionine-enkephalin (MET) and beta-endorphin upon human peripheral blood lymphocyte natural killer cell (NKC) activity in a group of healthy volunteers (n = 27; 17 male and 10 female, age +/- SD and range of 32 +/- 6, 25-43 years and 36 +/- 11, 22-65 years, respectively). Aliquots from some individual samples were preincubated(More)
Natural killer cell activity (NKCA) in patients with septic shock was statistically significantly lower than the value recorded for a group of drug-free, healthy volunteers [9.1 +/- 7.8 (n = 20) and 20.6 +/- 16.6 (n = 15), respectively; Student's test, p < 0.05]. As expected, preincubation of peripheral blood lymphocytes from samples taken from a group of(More)
Exposure of NIH/3T3 fibroblasts not expressing P-glycoprotein to 50, 30, 20, and 10% hyposmotic solutions led to cell volume increases of 70, 32, 21, and 12%, respectively. After swelling, NIH/3T3 cells exhibited regulatory volume decrease (RVD), attaining complete volume recovery after 30 min except in 50% hyposmotic solution, in which volume recovery was(More)
The association between Helicobacter pylori infection and gastric motility abnormalities is still controversial, partly because of the lack of an appropriate animal model. H. heilmannii type 1 (Hh1), a spiral bacterium that infects the stomach of both man and pigs, easily colonises and induces an inflammatory response in the gastric mucosa of rodents. For(More)
A series of tricyclic hydroquinones, incorporating a carbonyl group in the ortho position relative to the phenol function, were tested as inhibitors of oxygen uptake against the TA3 mouse carcinoma cell line and its multidrug-resistant variant TA3-MTX-R. The title compound, which proved to be the most active one, also exhibited low micromolar dose-dependent(More)
Natural killer cytolytic activity, the basis of cancer immunotherapy that uses cytolytic cells, may be impaired in cancer. The aim of this work was to study in vitro the natural killer cytolytic activity and its response to the immunomodulators interleukin-2, interferon and phytohemagglutinin stimulated lymphocyte proliferation in a group of 9 patients with(More)
Regulatory T cells (Treg) are important in the development of immune tolerance under normal physiological conditions. However, in pathological situations such as cancer, Treg increases have been correlated with bad prognoses. Treg depletion can be achieved in vitro under several stimuli, including the activation of the purinergic P2X7 receptor. Our aim was(More)