Time filter

Source Type

Rio de Janeiro, Brazil

Queto T.,Instituto Fernandes Figueira | Gaspar-Elsas M.I.,Instituto Fernandes Figueira | Masid-de-Brito D.,Instituto Fernandes Figueira | Vasconcelos Z.F.M.,Instituto Fernandes Figueira | And 6 more authors.
Journal of Leukocyte Biology | Year: 2010

IL-13 and eotaxin play important, inter-related roles in asthma models. In the lungs, CysLT, produced by the 5-LO-LTC4S pathway, mediate some local responses to IL-13 and eotaxin; in bone marrow, CysLT enhance IL-5-dependent eosinophil differentiation. We examined the effects of IL-13 and eotaxin on eosinophil differentiation. Semi-solid or liquid cultures were established from murine bone marrow with GM-CSF or IL-5, respectively, and the effects of IL-13, eotaxin, or CysLT on eosinophil colony formation and on eosinophil differentiation in liquid culture were evaluated, in the absence or presence of: a) the 5-LO inhibitor zileuton, the FLAP inhibitor MK886, or the CysLT1R antagonists, montelukast and MK571; b) mutations that inactivate 5-LO, LTC4S, or CysLT1R; and c) neutralizing mAb against eotaxin and its CCR3 receptor. Both cytokines enhanced GM-CSF-dependent eosinophil colony formation and IL-5-stimulated eosinophil differentiation. Although IL-13 did not induce eotaxin production, its effects were abolished by anti-eotaxin and anti-CCR3 antibodies, suggesting up-regulation by IL-13 of responses to endogenous eotaxin. Anti-CCR3 blocked eotaxin completely. The effects of both cytokines were prevented by zileuton, MK886, montelukast, and MK571, as well as by inactivation of the genes coding for 5-LO, LTC4S, and CysLT1R. In the absence of either cytokine, these treatments or mutations had no effect. These findings provide evidence for: a) a novel role of eotaxin and IL-13 in regulating eosinophilopoiesis; and b) a role for CysLTRs in bone marrow cells in transducing cytokine regulatory signals. © Society for Leukocyte Biology. Source

De Souza Ramos A.,Farmanguinhos | Ribeiro J.B.,Federal University of Rio de Janeiro | De Oliveira Lopes R.,Federal University of Rio de Janeiro | De Souza R.O.M.A.,Federal University of Rio de Janeiro
Synthetic Communications | Year: 2013

The b-ketoester tert-butyl acetoacetate was enantioselectively reduced to tertbutyl (S)-3-hydroxybutanoate by seven microorganism strains. The best result using free cells was obtained with the yeast R. rubra, which furnished 97.6% ee and higher than 99% of conversion within 24 h. After immobilization in calcium alginate spheres, R. rubra furnished 96% ee and higher than 99% ee within 24 h, even if substrate concentration was 58mM. Immobilized cells were reused three times without loss of enantioselectivity. Copyright © Taylor & Francis Group, LLC. Source

Ramos A.D.S.,Farmanguinhos | Ribeiro J.B.,Federal University of Rio de Janeiro | Lopes R.D.O.,Federal University of Rio de Janeiro | Leite S.G.F.,Federal University of Rio de Janeiro | Souza R.O.M.A.D.,Federal University of Rio de Janeiro
Tetrahedron Letters | Year: 2011

Seven wild-type microorganism strains were used to reduce ethyl 3-oxohexanoate to ethyl (R)-3-hydroxyhexanoate. Free cells of Kluyveromyces marxianus and Aspergillus niger led to higher than 99% of conversion with higher than 99% ee. After immobilization in calcium alginate spheres, cells of K. marxianus exhibited high enantioselectivity (>99% ee) and conversion level (99%) within 24 h even if substrate was added at concentration of 10 g/L (62 mM). © 2011 Elsevier Ltd. All rights reserved. Source

Fonseca L.B.,Federal University of Rio de Janeiro | Nele M.,Federal University of Rio de Janeiro | Volpato N.M.,Federal University of Rio Grande do Sul | Seiceira R.C.,Farmanguinhos | Pinto J.C.,Federal University of Rio de Janeiro
Macromolecular Reaction Engineering | Year: 2013

PZQ is the primary drug for treatment of schistosomiasis, but its efficiency is severely affected by its bitter taste. The main objective of this paper is the preparation of PMMA nanoparticles loaded with PZQ through in situ miniemulsion polymerizations and intended for oral formulations. Polymerizations are performed with an ultra turrax and a high-pressure homogenizer. Obtained nanoparticles are analyzed by DSC, HPLC, DLS, GC, SEM, and PZQ dissolution profiles. Obtained results indicate the successful encapsulation of PZQ in all runs. Obtained data also show that the high-pressure homogenizer leads to the best performance, allowing for preparation of stable latexes, with narrower particle size distributions and higher encapsulation efficiencies. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ribeiro I.M.,Farmanguinhos | Tomassini T.C.B.,Farmanguinhos | De Azevedo W.F.,University of Porto
Journal of Natural Products | Year: 2011

The antimalarial activities of physalins B, D, F, and G (1-4), isolated from Physalis angulata, were investigated. In silico analysis using the similarity ensemble approach (SEA) database predicted the antimalarial activity of each of these compounds, which were shown using an in vitro assay against Plasmodium falciparum. However, treatment of P. berghei-infected mice with 3 increased parasitemia levels and mortality, whereas treatment with 2 was protective, causing a parasitemia reduction and a delay in mortality in P. berghei-infected mice. The exacerbation of in vivo infection by treatment with 3 is probably due to its potent immunosuppressive activity, which is not evident for 2. © 2011 The American Chemical Society and American Society of Pharmacognosy. Source

Discover hidden collaborations