Search Results - (Author, Cooperation:M. A. Martins)

2012-10-02

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

AIDS Vaccines/*immunology ; Acquired Immunodeficiency Syndrome/*virology ; Animals ; CD8-Positive T-Lymphocytes/*immunology ; Disease Models, Animal ; Epitopes, T-Lymphocyte/immunology ; Female ; HIV-1/immunology ; HLA-B27 Antigen/immunology ; Humans ; Immunodominant Epitopes/immunology ; Macaca mulatta/immunology/virology ; Male ; SAIDS Vaccines/*immunology ; Simian Acquired Immunodeficiency Syndrome/immunology/*prevention & ; control/virology ; Simian Immunodeficiency Virus/growth & development/*immunology/pathogenicity ; Viral Load ; Viremia/immunology/prevention & control ; Virus Replication/*immunology

2018-03-06

Hindawi

1024-123X

1563-5147

Mathematics

Technology

2018-07-24

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The aim of this study was to investigate the role of immunoglobulin E (IgE) in the late phase reaction (LPR) of murine experimental asthma. Our model consisted of an implant of DNP-conjugated, heat-coagulated hen's egg white (DNP-EWI), followed 14 days later by an intratracheal challenge with aggregated DNP-ovalbumin. Airway inflammation was analyzed 48 h after challenge and compared with a similarly immunized group of mice with highly suppressed humoral response due to anti-μ and anti-δ antibody treatment. Total number of cells in the bronchoalveolar lavage (BAL) (with predominance of eosinophils) and EPO activity in the lung homogenate were increased in the DNP-EWI-immunized group compared with immunosuppressed or nonimmunized mice. However, the cellular infiltration and EPO activity observed in the immunosuppressed group were still significantly above those obtained in the nonimmunized group, indicating that inhibition of antibody production did not completely prevent the inflammatory manifestations in BAL and lung. Airway hyperresponsiveness to methacoline was obtained in DNP-EWI-immunized mice, but the respiratory mechanical parameters returned to normal levels in the immunosuppressed group. When these mice were reconstituted with monoclonal anti-DNP antibodies, only IgE, but not IgG1, restored lung inflammation and decreased the conductance of the respiratory system, therefore, increasing hyperresponsiveness. These results indicate that antibodies are not essential for induction of LPR in the lung. However, IgE enhances pulmonary inflammation and hyperresponsiveness.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background We have recently isolated two distinct components from Ascaris suum adult worms with different effects on the immune system: the allergenic protein of A. suum (APAS-3), which induces IgE antibody production, and suppressive protein of A. suum (PAS-1), which inhibits humoral and cellular immune responses induced by unrelated antigens. In this study, we investigated the immunomodulatory effect of PAS-1 on a murine model of asthma induced by APAS-3.Methods BALB/c mice were immunized twice with APAS-3 or APAS-3 plus PAS-1 by the intraperitoneal and subcutaneous route (on days 0 and 7) and challenged twice with the same antigens intranasally (days 14 and 21). Two days after the last challenge, the allergic airway inflammation was evaluated by cellular migration, eosinophil peroxidase (EPO) activity, cytokine and chemokine production and pulmonary mechanical parameters.Results The allergenic properties of APAS-3 were confirmed by the stimulation of anaphylactic IgE and IgG1 antibody production and eosinophilic airway inflammation and hyper-responsiveness. On the other hand, PAS-1-treated mice showed a marked suppression of cellular migration and EPO activity that correlated well with a significant reduction in the levels of IL-4, IL-5, eotaxin and RANTES in the bronchoalveolar lavage (BAL) fluid. In contrast, considerable amounts of IL-10 were observed in the BAL fluid of PAS-1-treated mice. Airway hyper-responsiveness was obtained in APAS-3-immunized mice, but the conductance of the respiratory system was restored to normal values in the presence of PAS-1.Conclusion These results indicate that A. suum allergenic protein APAS-3 induces a T helper 2-type immune response and, consequently, eosinophilic airway inflammation and hyper-responsiveness. Moreover, the modulatory protein PAS-1 has a marked suppressive effect on this response, and the inhibition of cytokine (IL-4, IL-5) and chemokine (eotaxin and RANTES) release, probably because of the presence of IL-10, may contribute to this effect.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Leukotriene receptor antagonists have been demonstrated in several studies to possess bronchodilating and anti-inflammatory properties in asthma. However, there are few experimental studies performed to compare the effects of anti-leukotrienes and glucocorticoids, most used anti-inflammatory agents in asthma. In the present study, we evaluated the effects of treatment with dexamethasone or montelukast on eosinophil and mononuclear cell recruitment in an experimental model of allergen-induced chronic airway inflammation in guinea-pigs (GP).Methods GP were submitted to increasing concentrations of aerosols of ovalbumin (OVA) twice a week for 4 weeks. After 2 weeks, animals were treated daily with dexamethasone, montelukast or saline solution. After this period, GP were anaesthetized, tracheostomized, mechanically ventilated and challenged with OVA aerosol.Results Maximal changes of respiratory system resistance and elastance induced by OVA challenge were attenuated by dexamethasone (P〈0.001), but not by montelukast treatment. Neither dexamethasone nor montelukast significantly influenced bronchial oedema formation. Dexamethasone but not montelukast induced a decrease in mononuclear cells in airways (P〈0.001). Eosinophil infiltration in the bronchial wall was reduced by both dexamethasone and montelukast (P〈0.005). Only dexamethasone treatment reduced the levels of exhaled nitric oxide (P〈0.025).Conclusion Although leukotriene receptor antagonist treatment reduces eosinophil accumulation induced by multiple antigen challenges, glucocorticoid treatment attenuates both eosinophil and mononuclear cell infiltration.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background The increase of atopic disorders in developed countries has been associated with the decline of infectious diseases, including helminthic infections. We have already demonstrated that adult worm extracts from Ascaris suum (ASC) suppress the IgE antibody production against unrelated antigens.Objective Here we investigated the influence of ASC on the development of pulmonary eosinophilic inflammation in a murine model of asthma.Methods Heat-coagulated egg white alone (EWI) or mixed with ASC (EWI + ASC) was implanted subcutaneously in B10.A or C57BL/6 mice, and 14 days later they were challenged intratracheally with OVA or exposed to aerosolized OVA for 4 days.Results The suppressive effect of ASC was demonstrated on the accumulation of cells into airways, with reduction of eosinophil numbers and of eosinophil peroxidase activity in EWI + ASC- immunized mice. This effect correlated with a marked reduction of IL-5 and IL-4 levels in the BAL from C57BL/6 and B10.A mice, respectively, and of eotaxin in BAL and lung tissue from both strains. OVA-specific IgG1 and IgE levels were also impaired in serum and BAL from these mice. Airway hyper-reactivity to methacholine was obtained in B10.A mice sensitized with EWI, but the respiratory mechanical parameters returned to normal levels in EWI + ASC-immunized mice.Conclusion These results indicate that ASC has a profound inhibitory effect on lung inflammation and hyper-responsiveness and that suppression of IL-5 or IL-4 and of eotaxin contributes to this effect.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Mice inoculated withPlasmodium berghei developed a drastic and significant pulmonary edema. Treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.

Electronic Resource

1573-2576

Springer Online Journal Archives 1860-2000

Medicine

Abstract PAF-acether (PAF) or 2-methoxy-PAF (2-MX) caused a dose-dependent paw edema showing a 1: 25 ratio between their inflammatory activities. 2-MX caused a thrombocytopenia, whereas PAF did not alter the number of these cells. Both phospholipids induced reductions in total leukocyte count. Rat antiplatelet serum produced platelet depletion by PAF-induced paw edema was unaffected. The edema of 2-MX was significantly reduced by antiplatelet serum, under conditions where normal serum was inactive against the edema induced by PAF or 2-MX. Histopathological analysis of PAF and 2-MX-induced edema showed, in the first case, a small infiltrate of neutrophils, some lymphocytes, and several mastocytes around the vessels and, in the second, a neutrophilic infiltrate. These results suggest that PAF and 2-MX may produce edema through different mechanisms and that 2-MX causes edema in part through platelet activation.

Electronic Resource

1572-9575

Springer Online Journal Archives 1860-2000

Physics

Abstract We consider a conformally flat, inhomogeneous solution of the Einstein equations for a dissipative fluid. The production of entropy is found to depend on some arbitrary functions of time. By some subsidiary conditions, such a model is shown to evolve into a homogeneous Friedmann-type universe.

Electronic Resource

1572-9532

Weyl metric ; line mass source

Springer Online Journal Archives 1860-2000

Physics

Abstract We study some known static vacuum solutions of Einstein's equations, namely, the A and B metrics of Ehlers and Kundt. All of them have axial symmetry, so they can be transformed to the Weyl form. In Weyl coordinates log √−g 44 obeys a Laplace equation, and from this a source, calledthe Newtonian image source, can be identified. We use the image sources to give a possible interpretation to the metrics. The procedure is successful in some cases. In others it fails because the Weyl transform does not have reasonable properties at infinity.

Electronic Resource