Miguel Alexandre Campos

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The innate immune system plays a critical role in the defense of areas exposed to microorganisms. There is an increasing body of evidence indicating that antimicrobial peptides and proteins (APs) are one of the most important weapons of this system and that they make up the protective front for the respiratory tract. On the other hand, it is known that(More)
The Yersinia pseudotuberculosis chromosome contains a seven-gene polycistronic unit (the pmrF operon) whose products share extensive homologies with their pmrF counterparts in Salmonella enterica serovar Typhimurium (S. typhimurium), another Gram-negative bacterial enteropathogen. This gene cluster is essential for addition of 4-aminoarabinose to the lipid(More)
The means by which airway epithelial cells sense a bacterial infection and which intracellular signalling pathways are activated upon infection are poorly understood. A549 cells and human primary airway cells (NHBE) were used to investigate the response to infection with Klebsiella pneumoniae. Infection of A549 and NHBE with K. pneumoniae 52K10, a capsule(More)
The aim of the present work was to elucidate the role played by ATP and Mg2+ ions in the early steps of the Na+,K(+)-ATPase cycle. The approach was to follow pre-steady-state phosphorylation kinetics in Na(+)-containing K(+)-free solutions under variable ATP and MgCl2 concentrations. The experiments were performed with a rapid mixing apparatus at 20 +/- 2(More)
The present work compares the effects of several ligands (phosphatase substrates, MgCl2, RbCl and inorganic phosphate) and temperature on the phosphatase activity and the E2(Rb) occluded conformation of Na+/K+-ATPase. Cooling from 37 degrees C to 20 degrees C and 0 degrees C (hydrolysis experiments) or from 20 degrees C to 0 degrees C (occlusion(More)
The K+-dependent p-nitrophenylphosphatase activity catalyzed by purified (Na+ + K+)-ATPase from pig kidney shows substrate inhibition (Ki about 9.5 mM at 2.1 mM Mg2+). Potassium antagonizes and sodium favours this inhibition. In addition , K+ reduces the apparent affinity for substrate activation, whereas p-nitrophenyl phosphate reduces the apparent(More)
Two cataract-free-zone projects, one in Brazil and the other in Peru, were designed to provide surgery to all those who need and want it within a defined geographic area. In-home visual acuity screening was accepted by three-fourths of the enumerated population aged 50 years or more. Those with reduced bilateral visual acuity were referred to a community(More)
Airway epithelial cells act as the first barrier against pathogens. These cells recognize conserved structural motifs expressed by microbial pathogens via Toll-like receptors (TLRs) expressed on the surface. In contrast to the level of expression in lymphoid cells, the level of expression of TLR2 and TLR4 in airway epithelial cells is low under(More)
Based on work of Post et al. (Post, R. L. Toda, G., and Rogers, F.N. (1975) J. Biol, Chem. 250, 691-701), we studied the E2 form reactivity of Na(+),K(+)-ATPase (EC during Na(+)-ATPase turnover by following ATP hydrolysis with and without P(i) and enzyme phosphorylation from P(i) at 20 degrees C. For theoretical calculations we employed the(More)
The treatment of infections caused by bacteria resistant to the vast majority of antibiotics is a challenge worldwide. Antimicrobial peptides (APs) make up the front line of defense in those areas exposed to microorganisms, and there is intensive research to explore their use as new antibacterial agents. On the other hand, it is known that subinhibitory(More)