221 resultados para peasant production
Resumo:
In this Letter we study the process of gluon fusion into a pair of Higgs bosons in a model with one universal extra dimension. We find that the contributions from the extra top quark Kaluza-Klem excitations lead to a Higgs pair production cross section at the LHC that can be significantly altered compared to the Standard Model value for small values of the compactification scale. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
Pulmonary macrophages (PM), which are CD11b/CD18(+) and CD23(+), may be involved in the onset of inflammatory events caused by Paracoccidioides brasiliensis in the lungs. In the present study, we measured the nitric oxide (NO) and interleukin in PM production after intratracheal (i.t.) inoculation of an enriched beta-glucan cell wall fraction from P. brasiliensis (Fraction F1). BALB/c and C57/BL6 (B6) mice were i.t. treated with Fraction F1, and their PM were restimulated in vitro with LPS and interferon-gamma up to 14 days after treatment. Macrophages BALB/c mice produced less NO than PM from B6 mice. The lower NO production was caused by higher production of TGF-beta by pulmonary macrophages of BALB/c and was abrogated by anti-TGF-beta MoAb in vitro and in vivo. Other interleukins such as IL-10, IL-4 and a combination of IL-1, TNF-alpha and IL-6 were not involved in NO production induced by Fraction F1. Expression of CD11b increases and expression of CD23 decreases on PM of BALB/c mice after in vivo treatment whereas PM of B6 mice do not show a variation of their phenotype. Moreover, the ability of pulmonary macrophages to induce lymphocyte proliferation was reduced in mixed cultures of CD11b(+) or CD23(+) macrophages but was restored when lymphocytes were cultivated in the presence of NO inhibitor (L-NMMA). Thus, the results presented herein indicate that in BALB/c but not in B6 mice TGF- is strongly induced by Fraction 1 in PM in vivo and suppresses NO production. Low NO production by PM is associated with a change in CD11b/CD23 expression and with a high lymphocyte proliferative response. Thus, CD11b(+)/CD23(+) PM modulate NO and TGF-beta production in the pulmonary microenvironment.
Resumo:
We present a comparative study of the physico-chemical properties, in vitro cytotoxicity and in vivo antibody production of surface-complexed DNA in EPC/DOTAP/DOPE (50/25/25% molar) liposomes and DOTAP/DOPE (50/50% molar) lipoplexes. The study aims to correlate the biological behavior and structural properties of the lipid carriers. We used DNA-hsp65, whose naked action as a gene vaccine against tuberculosis has already been demonstrated. Additionally, surface-complexed DNA-hsp65 in EPC/DOTAP/DOPE (50/25/25% molar) liposomes was effective as a single-dose tuberculosis vaccine. The results obtained showed that the EPC inclusion stabilized the DOTAP/DOPE structure, producing higher melting temperature and lower zeta potential despite a close mean hydrodynamic diameter. Resemblances in morphologies were identified in both structures, although a higher fraction of loaded DNA was not electrostatically bound in EPC/DOTAP/DOPE. EPC also induced a striking reduction in cytotoxicity, similar to naked DNA-hsp65. The proper immune response lead to a polarized antibody production of the IgG2a isotype, even for the cytotoxic DOTAP/DOPE. However, the antibody production was detected at 15 and 30 days for DOTAP/DOPE and EPC/DOTAP/DOPE, respectively. Therefore, the in vivo antibody production neither correlates with the in vitro cytotoxicity, nor with the structural stability alone. The synergistic effect of the structural stability and DNA electrostatic binding upon the surface of structures account for the immunological effects. By adjusting the composition to generate proper packing and cationic lipid/DNA interaction, we allow for the optimization of liposome formulations for required immunization or gene therapy. In a specific manner, our results contribute to studies on the tuberculosis therapy and vaccination. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Hemophilia B is a genetic disease of the coagulation system that affects one in 30,000 males worldwide. Recombinant human Factor IX (rhFIX) has been used for hemophilia B treatment, but the amount of active protein generated by these systems is inefficient, resulting in a high-cost production of rhFIX. In this study, we developed an alternative for rhFIX production. We used a retrovirus system to obtain two recombinant cell lines. We first tested rhFIX production in the human embryonic kidney 293 cells (293). Next, we tested a hepatic cell line (HepG2) because FIX is primarily expressed in the liver. Our results reveal that intracellular rhFIX expression was more efficient in HepG2/rhFIX (46%) than in 293/rhFIX (21%). The activated partial thromboplastin time test showed that HepG2/rhFIX expressed biologically active rhFIX 1.5 times higher than 293/rhFIX (P = 0.016). Recovery of rhFIX from the HepG2 by reversed-phase chromatography was straightforward. We found that rhFIX has a pharmacokinetic profile similar to that of FIX purified from human plasma when tested in hemophilic B model. HepG2/rhFIX cell line produced the highest levels of rhFIX, representing an efficient in vitro expression system. This work opens up the possibility of significantly reducing the costs of rhFIX production, with implications for expanding hemophilia B treatment in developing countries.
Resumo:
Mesenchymal stromal cells (MSCs) suppress T cell responses through mechanisms not completely understood. Adenosine is a strong immunosuppressant that acts mainly through its receptor A(2a) (ADORA2A). Extracellular adenosine levels are a net result of its production (mediated by CD39 and CD73), and of its conversion into inosine by Adenosine Deaminase (ADA). Here we investigated the involvement of ADO in the immunomodulation promoted by MSCs. Human T lymphocytes were activated and cultured with or without MSCs. Compared to lymphocytes cultured without MSCs, co-cultured lymphocytes were suppressed and expressed higher levels of ADORA2A and lower levels of ADA. In co-cultures, the percentage of MSCs expressing CD39, and of T lymphocytes expressing CD73, increased significantly and adenosine levels were higher. Incubation of MSCs with media conditioned by activated T lymphocytes induced the production of adenosine to levels similar to those observed in co-cultures, indicating that adenosine production was mainly derived from MSCs. Finally, blocking ADORA2A signaling raised lymphocyte proliferation significantly. Our results suggest that some of the immunomodulatory properties of MSCs may, in part, be mediated through the modulation of components related to adenosine signaling. These findings may open new avenues for the development of new treatments for GVHD and other inflammatory diseases. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
Aims: To evaluate the intracellular production of tumor necrosis factor (TNF-alpha), interleukine-6 (IL-6), INF-gamma, IL-8 and IL-10 in peripheral blood lympbomononuclear cells from type 1 and type 2 diabetic patients, stratified according to the glycemic control. Methods: Thirty-five diabetic patients (17 type 1 and 18 type 2) and nine healthy individuals paired to patients in terms of sex and age were studied. Nine patients of each group were on inadequate glycemic controls. Intracellular cytokines were evaluated using flow cytometry. Cell cultures were stimulated with LPS to evaluate TNF-alpha and IL-6 or with PMA and lonomycin to evaluate IFN-gamma, IL-8 and IL-10 intracellular staining. Results: The percentages of CD33(+) cells bearing TNF-alpha and CD3(+) cells bearing IL-10 were increased in type 1 diabetic patients with inadequate glycemic control in relation to those with adequate control. In contrast, the percentage of CD3(+) cells bearing IL-8 was decreased in type 2 patients under inadequate glycemic control. Conclusions: The glycemic control is important for the detection of intracellular cytokines, and may contribute towards the susceptibility to infections in diabetic patients. (c) 2008 Elsevier Ireland Ltd. All rights reserved.
Resumo:
To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus ( SLE), the superoxide anion (O(2)(-)) production by neutrophils, mediated by Fc gamma R and Fc gamma R/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: ( 1) manifestations associated with the occurrence of cytotoxic antibodies ( SLE-I group); ( 2) manifestations associated with circulating immune complexes ( IC; SLE-II group), and ( 3) manifestations associated with IC and cytotoxic antibodies ( SLE-III group). O(2)(-) production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with ICIgG opsonized or not with complement. No difference in O(2)(-) production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: ( 1) SLE-I neutrophils showed lower O(2)(-) production mediated by the IgG receptor ( Fc gamma R) with the cooperation of complement receptors ( Fc gamma R/ CR) than observed in the SLE-II, SLE-III, and healthy groups; ( 2) neutrophils from the SLE-II group showed a decreased O(2)(-) production mediated by Fc gamma R/ CR compared to the SLE-III group, ( 3) SLE-III neutrophils produced more O(2)(-) than neutrophils from the SLE-II and control groups, and ( 4) CR showed inefficiency in mediating the O(2)(-) production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence ( CL; T(max) and CL(max)) disclosed differences only for the SLE- I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by Fc gamma R/ CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.
Resumo:
This study aims to evaluate the production of cytokines, tumor necrosis factor (TNF), and interleukin 10 (IL-10) in peripheral blood mononuclear cells (PBMCs) from type 1 diabetic (T1D) patients by means of intracellular staining, flow cytometry, and ELISA and to correlate it with inadequate (IN) and adequate (A) metabolic controls. We studied 28 patients with T1D and 20 healthy individuals (C) paired by sex and age. T1D patients were divided in patients with IN and A metabolic control. PBMC cultures were stimulated with LPS to evaluate TNF or were stimulated with PMA/ionomycin or concanavalin A to evaluate IL-10. The TNF levels in supernatant of stimulated cultures, evaluated by ELISA, of diabetic patients were similar to those of healthy individuals, although the percentage of CD 33(+) cells that were positive for TNF was higher in the T1D IN group compared to the T1D A group (P = 0.01). Similarly, the IL-10 levels evaluated by ELISA in stimulated cultures of T1D patients were not different from those in the control group; moreover, the percentage of CD3(+) cells positive for intracellular IL-10 were higher in the T1D IN group compared to C groups (P = 0.007). The increased levels of cytokines in T1D IN diabetic patients, with reduction in the A group, suggests that hyperglycemia stimulates an inflammatory state that can result in a deficient immune cellular response. The data suggest that assessment by intracellular staining seems to be more accurate than the ELISA technique in evaluating diabetic patients.
Resumo:
IL-23/IL-17-induced neutrophil recruitment plays a pivotal role in rheumatoid arthritis (RA). However, the mechanism of the neutrophil recruitment is obscure. Here we report that prostaglandin enhances the IL-23/IL-17-induced neutrophil migration in a murine model of RA by inhibiting IL-12 and IFN gamma production. Methylated BSA (mBSA) and IL-23-induced neutrophil migration was inhibited by anti-IL-23 and anti-IL-17 antibodies, COX inhibitors, IL-12, or IFN gamma but was enhanced by prostaglandin E(2) (PGE(2)). IL-23-induced IL-17 production was increased by PGE(2) and suppressed by COX-inhibition or IL-12. Furthermore, COX inhibition failed to reduce IL-23-induced neutrophil migration in IL-12- or IFN gamma-deficient mice. IL-17-induced neutrophil migration was not affected by COX inhibitors, IL-12, or IFN gamma but was inhibited by MK886 (a leukotriene synthesis inhibitor), anti-TNF alpha, anti-CXCL1, and anti-CXCL5 antibodies and by repertaxin (a CXCR1/2 antagonist). These treatments all inhibited mBSA- or IL-23-induced neutrophil migration. IL-17 induced neutrophil chemotaxis through a CXC chemokines-dependent pathway. Our results suggest that prostaglandin plays an important role in IL-23-induced neutrophil migration in arthritis by enhancing IL-17 synthesis and by inhibiting IL-12 and IFN gamma production. We thus provide a mechanism for the pathogenic role of the IL-23/IL-17 axis in RA and also suggest an additional mechanism of action for nonsteroidal anti-inflammatory drugs.
Resumo:
Quercetin (1) is known to have both antioxidant and antinociceptive effects. However, the mechanism involved in its antinociceptive effect is not fully elucidated. Cytokines and reactive oxygen species have been implicated in the cascade of events resulting in inflammatory pain. Therefore, we evaluated the antinociceptive mechanism of 1 focusing on the role of cytokines and Oxidative stress. Intraperitoneal and oral treatments with 1 dose-dependently inhibited inflammatory nociception induced by acetic acid and phenyl-p-benzoquinone and also the second phase of formalin- and carrageenin-induced mechanical hypernociception. Compound I also inhibited the hypernociception induced by cytokines (e.g., TNF alpha and CXCL1), but not by inflammatory mediators that directly sensitize the nociceptor such as PGE(2) and dopamine. On the other hand, 1 reduced carrageenin-induced IL-1 beta production as well as carrageenin-induced decrease of reduced glutathione (GSH) levels. These results suggest that I exerts its analgesic effect by inhibiting pro-nociceptive cytokine production and the oxidative imbalance mediation of inflammatory pain.
Resumo:
Background Evaluate the production of TNF and IL-6 in the supernatant of peripheral blood mononuclear cell (PBMC) cultures of patients with supraglottic laryngeal cancer before and after surgical treatment. Materials and methods Adherent cell cultures were stimulated with LPS and BCG. Fourteen patients with advanced supraglottic laryngeal cancer were studied. Cytokine concentration was determined by ELISA in supernatants of mononuclear cell cultures. Results In non-stimulated cultures, lower TNF cytokine levels were detected during the late postoperative (LP) period compared to control (P = 0.02). LP TNF and IL-6 levels were high in cultures stimulated with LPS compared with the preoperative period (PREOP) (P = 0.007; P = 0.008, respectively). Stimulation with BCG led to increased levels of TNF and IL-6 during the LP period compared to control (P = 0.001; P = 0.04, respectively). Conclusions BCG is able to modulate the immune response of patients with advanced supraglottic laryngeal cancer in vitro, increasing the secretion of TNF and IL-6 by macrophages during the postoperative period.
Resumo:
Background & aim: Many disease outbreaks of food origin are caused by foods prepared in Food Service and Nutrition Units of hospitals, affecting hospitalized patients who, in most cases, are immunocompromised and therefore at a higher risk of severe worsening of their clinical status. The aim of this study was to determine the variations in temperature and the time-temperature factor of hospital diets. Methods: The time and temperature for the preparation of 4 diets of modified consistency were determined on 5 nonconsecutive days in a hospital Diet and Nutrition Unit at the end of preparation and during the maintenance period, portioning and distribution at 3 sites, i.e., the first, the middle and the last to receive the diets. Results and discussion: All foods reached an adequate temperature at the end of cooking, but temperature varied significantly from the maintenance period to the final distribution, characterizing critical periods for microorganism proliferation. During holding, temperatures that presented a risk were reached by 16.7% of the meats and 59% of the salads of the general diet, by 16.7% of the garnishes in the bland diet and by 20% of the meats and garnishes in the viscous diet. The same occurred at the end of distribution for 100% of the hot samples and of the salads and for 61% of the desserts. None of the preparations remained at risk temperature for a time exceeding that established by law. Conclusion: The exposure to inadequate temperature did not last long enough to pose risks to the patient.
Resumo:
Rocio virus (ROCV) is a flavivirus, probably transmitted by Culex mosquitoes and maintained in nature as a zoonosis of wild birds. Rocio virus caused a human epidemic of severe encephalitis that lasted from 1973 to 1980 in the Ribeira valley, in the southeastern coast of Brazil. After this outbreak, serologic evidence of ROCV circulation has been reported and public health authorities are concerned about a return of ROCV outbreaks in Brazil. We show here a study on the pathogenesis and the physiopathology of ROCV disease in the central nervous system of a Balb/C young adult mice experimental model. The animals were intraperitoneally infected by ROCV and followed from 0 to 9 days after infection, when all of them died. Nervous tissue samples were collected from infected animals for immunohistochemistry and molecular biology analysis. We observed the virus in the central nervous system, the inflammatory changes induced by Th1 and Th2 cytokines, and the final irreversible damage of nervous tissues by neuronal degeneration and apoptosis. These findings can help to better understand the pathogenesis and physiopathology of the human meningoencephalomyelitis by ROCV and other flaviviruses.
Resumo:
In this study we aimed at evaluating the effect of the major polar constituents of the medicinal plant Lychnophora ericoides on the production of inflammatory mediators produced by LPS-stimulated U-937 cells. The 6,8-di-C-beta-glucosylapigenin (vicenin-2) presented no effect on tumor necrosis factor (TNF)-alpha production, but inhibited, in a dose-dependent manner, the production of prostaglandin (PG) E(2) without altering the expression of cyclooxygenase (COX) -2 protein. 3,5-Dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid, at lower concentrations, had small but significant effects on reducing PG E, levels; at higher doses these compounds stimulated PGE(2) and also TNF-alpha production by the cells. All the caffeoylquinic acid derivatives, in a dose-dependent fashion, were able to inhibit monocyte chemoattractant protein-3 synthesis/release, with 4,5-DCQ being the most potent at the highest tested concentration. These results add important information on the effects of plant natural polyphenols, namely vicenin-2 and caffeoylquinic acid derivatives, on the production of inflammatory mediators by cultured cells.
Resumo:
When infected with Trypanosoma cruzi, Beagle dogs develop symptoms similar to those of Chagas disease in human beings, and could be an important experimental model for a better understanding of the immunopathogenic mechanisms involved in chronic chagasic infection. This study evaluates IL-10, IFN-gamma and TNF-alpha production in the sera, culture supernatant, heart and cervical lymph nodes and their correlation with cardiomegaly, cardiac inflammation and fibrosis in Beagle dogs infected with T. cruzi. Pathological analysis showed severe splenomegaly, lymphadenopathy and myocarditis in all infected dogs during the acute phase of the disease, with cardiomegaly, inflammation and fibrosis observed in 83% of the animals infected by T. cruzi during the chronic phase. The data indicate that infected animals producing IL-10 in the heart during the chronic phase and showing high IL-10 production in the culture supernatant and serum during the acute phase had lower cardiac alterations (myocarditis, fibrosis and cardiomegaly) than those with high IFN-gamma and TNF-alpha levels. These animals produced low IL-10 levels in the culture supernatant and serum during the acute phase and did not produce IL-10 in the heart during the chronic phase of the disease. Our findings showed that Beagle dogs are a good model for studying the immunopathogenic mechanism of Chagas disease, since they reproduce the clinical and immunological findings described in chagasic patients. The data suggest that the development of the chronic cardiac form of the disease is related to a strong Th1 response during the acute phase of the disease, while the development of the indeterminate form results from a blend of Th1 and Th2 responses soon after infection, suggesting that the acute phase immune response is important for the genesis of chronic cardiac lesions. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.