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Human Polymorphonuclear Leucocytes (human + polymorphonuclear_leucocyte)
Selected AbstractsInteraction of amphotericin B lipid formulations and triazoles with human polymorphonuclear leucocytes for antifungal activity against ZygomycetesMYCOSES, Issue 2 2008Maria Simitsopoulou Summary The frequency of zygomycosis has increased considerably over recent years mainly in immunocompromised and diabetic patients. Little is known about the effects of host innate immunity against different Zygomycetes especially under the influence of antifungal agents. The antifungal activity of human polymorphonuclear leucocytes (PMN) in combination with liposomal amphotericin B (LAMB), amphotericin B lipid complex (ABLC), voriconazole (VRC) and posaconazole (PSC) against Rhizopus oryzae and Rhizopus microsporus, frequently isolated Zygomycetes, were studied and compared with Absidia corymbifera, a less pathogenic Zygomycete. Antifungal activity was evaluated as per cent of hyphal damage using the XTT metabolic assay. While A. corymbifera was more susceptible to PMN than the other two Zygomycetes, R. microsporus appeared to be the most susceptible to combined effects of amphotericin B formulations and VRC with PMN. LAMB exhibited synergistic activity with PMN in inducing hyphal damage to R. microsporus but not to the other fungi. In contrast, ABLC exhibited synergistic or additive activity with PMN against all three fungi. Among triazoles, only VRC exhibited additive effect with PMN against R. microsporus. Lipid formulations of amphotericin B and particularly ABLC interact with PMN predominantly in inducing augmented hyphal damage to three different species of Zygomycetes. [source] Tachykinin receptor modulation of cyclooxygenase-2 expression in human polymorphonuclear leucocytesBRITISH JOURNAL OF PHARMACOLOGY, Issue 3 2009M Gallicchio Mandarin translation of abstract Background and purpose:, We investigated the ability of natural and synthetic selective NK receptors agonists and antagonists to modulate cyclooxygenase-2 (COX-2) expression in human polymorphonuclear leucocytes (PMNs). Experimental approach:, The presence of all three tachykinin in PMNs was assessed by Western blot and PCR techniques. Natural and synthetic ligands selective for the tachykinin receptors were used to modulate COX-2 protein (measured with Western blotting) and activity [as prostaglandin E2 (PGE2) output]. Effects of substance P (SP) on phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-,B) activation were studied to analyse the signalling pathway involved in COX-2 up-regulation mediated by SP. Key results:, Stimulation of NK receptors with the natural ligands SP, neurokinin A (NKA) and neurokinin B, in the pmol·L,1 -µmol·L,1 concentration range, modulated COX-2 expression and PGE2 release in a concentration- and time-dependent manner. Experiments with synthetic selective agonists [Sar9, Met(O2)11]SP, [,-Ala8] NKA(4-10), senktide or selective antagonists L703,606, SR48,968 or SR142801, confirmed that COX-2 up-regulation was mediated by NK receptors. We found that mainly p38, p42 and p46 MAPKs were phosphorylated by SP and SB202190, PD98059 and SP600125, which are selective inhibitors of these kinases, blocked SP-induced COX-2 expression. SP also induced nuclear translocation of NF-,B concentration-dependently, with a maximum effect at 1 nmol·L,1. Conclusions and implications:, Human PMNs possess functional NK1, NK2 and NK3 receptors, which mediate the induction of COX-2 expression and NF-,B activation by SP. Mandarin translation of abstract [source] | ||||||||||