15 resultados para immunological activity

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 µg/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 µmols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 µg/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The effects of isolated compounds from Brazilian lichens and their derivatives on H 2O 2 and NO production were studied using murine macrophages as a part of an attempt to understand their possible immunomodulatory properties. The compound cytotoxicity was studied using MTT assay. Macrophage stimulation was evaluated by the determination of NO (Griess assay) and H 2O 2 (horseradish peroxidase/phenol red) in supernatants of peritoneal macrophage cultures of Swiss mice. This research demonstrated stimulatory activities of some phenolic compounds isolated from lichens and their derivatives on H 2O 2 and NO production. Structure-activity relationships suggest several synthetic directions for further improvement of immunological activity.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The main function of the immune system is the defense against infection, being composed by the leukocytes that modulate the immune response, which can be innate or adaptive. The physical exercise can causes positive or negative alterations in the total or relative number of leukocytes. When the exercise has a low or moderate intensity it`s considered beneficial for improving the function of the cells responsible for the defense and to reduce the risk of infectious illnesses. The type 2 diabetes is related to an incapacity of the body in rightly respond to insulin, associated to an resistance to its actions. The purpose of this research was to make a study of the immune system characteristics, as well as the type 2 diabetes and the relation among both and the physical exercise. So, it was analyzed a group of type 2 diabetics coming from Diabetics House of Franca -SP, treated through a program of mix physical training. Two collections of blood were pre and post training program for the pair comparable of the participants. It was found positive alterations of the subpopulations of leukocytes that show a probable improvement of the immunological state what allows us to suggest about a possible improvement of the immunological activity, what would be measured by the activation of these cells forward to an inflammatory/infectious condition. So, we suggest that future studies involving diabetes, immune system and physical exercise be encouraged.

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We investigated the effects of treatments with the enzymes pepsin and trypsin on the in vitro immunological reactivity of the major globulins found in the seeds of sweet lupin, chickpea, and lentil. Polyclonal major globulin-specific antiserum was obtained by immunization of rabbits with a solution of the 11 S globulin of each legume. The globulins were hydrolyzed with pepsin and trypsin for 1, 5, 15, and 30 min. The native globulins and their hydrolysates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify the polypeptide bands with antigenic activity, and the hypoantigenicity of the hydrolysates was analyzed by enzyme-linked immunosorbent assay. Our results show that enzymatic treatment of the major storage protein (11 S globulin) of sweet lupin, chickpea, and lentil with pepsin or trypsin lead to the formation of large amounts of short peptides and free amino acids that do not allow antibody binding, resulting in a weakened immunoreactivity.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The aim of the present study was to evaluate the role of macrophage activity and antibody production in experimental infection with Leptospira Pomona in mice genetically selected for high (H) or low (L) humoral immune response. To evaluate macrophage activity, reactive oxygen and nitrogen intermediates were determined. Also, the production of tumor necrosis factor (TNF-alpha) and the recovery of Leptospira-specific antibodies in the kidneys and liver were assessed; histological lesions were analyzed using the hematoxylin-eosin technique, and Leptospira antigens in tissues were determined by immunohistochemistry. Results showed that recovery of microorganisms from the analyzed organs was lower in LIV-A mice. However, HIV-A animals showed total restraint since the 14th day after infection, whereas LIV-A mice still had bacteria in the liver at the 21st post-infection day. Immune response against Pomona serovar in those lineages was characterized as high production of antibodies, mainly in late periods of the infectious process. The production of reactive oxygen and nitrogen intermediates also contributed to the elimination of Leptospira Pomona in all two lineages; H2O2 production was an important factor in HIV-A mice, as well as NO production in the LIV-A animals, mainly at the latest post-inoculation periods. The same occurred regarding TNF-alpha production. Severe renal lesions were observed at periods in which larger numbers of leptospires were isolated using the culture technique. Tissue alterations persisted in LIV-A mice, even at periods in which leptospires were not recovered. Immunohistochemistry showed to be more sensitive than culturing. However, both techniques were appropriate for the agent identification in the studied lineages. Results suggest that such lineages could represent an important model to investigate pathogenesis and immune response against the varied serovars of leptospires.

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We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment 1), we analyzed two antigen lots of two human isolates (Bt1 and Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh and Morton medium) in SDS-PAGE and in two immunological tests (immunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment 2), we compared the antigenic profile of three antigen hatches from three human isolates (Bt1, Bt2 and Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment 1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment 2, the reference system for P brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions.

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Natural killer (NK) cells play an important role in immune surveillance against tumors. The present work aimed to study the cytotoxic activity of NK cells and T cell subsets in peripheral blood of 13 patients with primary tumors in central nervous system (CNS). As controls 29 healthy subjects with the age range equivalent to the patients were studied. The methods employed were: a) determination of cytotoxic activity of NK cells towards K562 target cells, evaluated by single cell-assay; b) enumeration of CD3+ lymphocytes and their CD4+ and CD8+ subsets defined by monoclonal antibodies; c) the identification of tumors were done by histologic and immunochemistry studies. The results indicated that adults and children with tumor in CNS display reduced percentage of total T cells, helper/inducer subset and low helper/suppressor ratio. The cytotoxic activity of NK cells was decreased in patients with CNS tumors due mainly to a decrease in the proportion of target-binding lymphocytes. These results suggest that cytotoxic activity of NK cells may be affected by the immunoregulatory disturbances observed in patients with primary tumors in CNS.

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Objective. To identify preliminary core sets of outcome variables for disease activity and damage assessment in juvenile systemic lupus erythematosus (JSLE) and juvenile dermatomyositis (JDM). Methods. Two questionnaire surveys were mailed to 267 physicians from 46 different countries asking each member to select and rank the response variables used when assessing clinical response in patients with JSLE or JDM. Next, 40 paediatric rheumatologists from 34 countries met and, using the nominal group technique, selected the domains to be included in the disease activity and damage core sets for JSLE and JDM. Results. A total of 41 response variables for JSLE and 37 response variables for JDM were selected and ranked through the questionnaire surveys. In the consensus conference, domains selected for both JSLE and JDM activity or damage core sets included the physician and parent/patient subjective assessments and a global score tool. Domains specific for JSLE activity were the immunological tests and the kidney function parameters. Concerning JDM, functional ability and muscle strength assessments were indicated for both activity and damage core sets, whereas serum muscle enzymes were included only in the activity core set. A specific paediatric domain called 'growth and development' was introduced in the disease damage core set for both diseases and the evaluation of health-related quality of life was advised in order to capture the influence of the disease on the patient lifestyle. Conclusions. We developed preliminary core sets of measures for disease activity and damage assessment in JSLE and JDM. The prospective validation of the core sets is in progress.

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Recent studies have shown that ingestion by the army worm Spodoptera frugiperda of Cry1Ac toxin from Bt cotton promotes histochemical and ultrastructural changes in the digestive cells of the predatory pentatomid bug Podisus nigrispinus. Therefore, mindful of the changes in the midgut of the predator, which represents the first line of defence in this insect, our aim was to test the hypothesis that the consumption of Bt cotton-fed S. frugiperda by P. nigrispinus might lead to alterations in components of the immune system of P. nigrispinus. The Cry1Ac toxin level in the leaves of Bt cotton, nitric oxide, phenoloxidase activity, and total proteins were quantified by ELISA. Total and differential hemocyte counts were evaluated, and hemocyte ultrastructure analysis was undertaken. We found that ingestion of the prey fed daily with approximately 23 ± 0.70 ng g-1 Cry1Ac by wet weight of leaves, and expressed by the Bt cotton, induces small ultrastructural changes in the predator's granulocytes and plasmatocytes. However, these changes did not affect the total number and differential and humoral variables analyzed for the bug's hemocytes. © 2013 Copyright Taylor and Francis Group, LLC.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)