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151.
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153.
Claudia NCD Lemos Fernando M Reis Guilherme N Pena Laila C Silveira Aroldo F Camargos 《Reproductive biology and endocrinology : RB&E》2010,8(1):51
Background
Reproductive function following chemotherapy is of increasing importance given that survival rates are improving. We assessed whether a gonadotropin-releasing hormone antagonist (GnRHant; cetrorelix) could promote ovarian protection against damage due to chemotherapy. 相似文献154.
Ana-Carolina Oliveira Bruna C. de Alencar Fanny Tzelepis Weberton Klezewsky Raquel N. da Silva Fabieni S. Neves Gisele S. Cavalcanti Silvia Boscardin Marise P. Nunes Marcelo F. Santiago Alberto Nóbrega Maurício M. Rodrigues Maria Bellio 《PLoS pathogens》2010,6(4)
The murine model of T. cruzi infection has provided compelling evidence that development of host resistance against intracellular protozoans critically depends on the activation of members of the Toll-like receptor (TLR) family via the MyD88 adaptor molecule. However, the possibility that TLR/MyD88 signaling pathways also control the induction of immunoprotective CD8+ T cell-mediated effector functions has not been investigated to date. We addressed this question by measuring the frequencies of IFN-γ secreting CD8+ T cells specific for H-2Kb-restricted immunodominant peptides as well as the in vivo Ag-specific cytotoxic response in infected animals that are deficient either in TLR2, TLR4, TLR9 or MyD88 signaling pathways. Strikingly, we found that T. cruzi-infected Tlr2−/−, Tlr4−/−, Tlr9−/
− or Myd88−/− mice generated both specific cytotoxic responses and IFN-γ secreting CD8+ T cells at levels comparable to WT mice, although the frequency of IFN-γ+CD4+ cells was diminished in infected Myd88−/− mice. We also analyzed the efficiency of TLR4-driven immune responses against T. cruzi using TLR4-deficient mice on the C57BL genetic background (B6 and B10). Our studies demonstrated that TLR4 signaling is required for optimal production of IFN-γ, TNF-α and nitric oxide (NO) in the spleen of infected animals and, as a consequence, Tlr4−/− mice display higher parasitemia levels. Collectively, our results indicate that TLR4, as well as previously shown for TLR2, TLR9 and MyD88, contributes to the innate immune response and, consequently, resistance in the acute phase of infection, although each of these pathways is not individually essential for the generation of class I-restricted responses against T. cruzi. 相似文献
155.
The partition coefficients (K(p)) between lipid bilayers of dimyristoyl-L-alpha-phosphatidylglycerol (DMPG) unilamellar liposomes and water were determined using derivative spectrophotometry for chlordiazepoxide (benzodiazepine), isoniazid and rifampicin (tuberculostatic drugs) and dibucaine (local anaesthetic). A comparison of the K(p) values in water/DMPG with those in water/DMPC (dimyristoyl-L-alpha-phosphatidylcholine) revealed that for chlordiazepoxide and isoniazid, neutral drugs at physiological pH, the partition coefficients are similar in anionic (DMPG) and zwitterionic (DMPC) liposomes. However, for ionised drugs at physiological pH, the electrostatic interactions are different with DMPG and DMPC, with the cationic dibucaine having a stronger interaction with DMPG, and the anionic rifampicin having a much larger K(p) in zwitterionic DMPC. These results show that liposomes are a better model membrane than an isotropic two-phase solvent system, such as water-octanol, to predict drug-membrane partition coefficients, as they mimic better the hydrophobic part and the outer polar charged surface of the phospholipids of natural membranes. 相似文献
156.
Calculating growth parameters of Genidens barbus (Siluriformes, Ariidae) using length composition and age data 总被引:1,自引:0,他引:1
The marine catfish Genidens barbus was once one of the most important estuarine fishery resources in the Patos Lagoon (southern Brazil), which had the largest population known for the species. However, clear signs of overfishing have been observed since the 1980s. Growth parameters for this population were estimated by combining length frequency data for juveniles and selected published data on annuli reading from adult otoliths. This methodology yielded a more realistic set of parameters using both the specialized and generalized von Bertalanffy growth model. The species growth can be described as: Lt = 118.6[1 − e−0.043(t+1.505)] or Lt = 104.6[1 −e−0.137D(t+4.013)]1/D with the surface factor D = 0.542. The growth performance index ϕ′ was estimated as 2.78 for the special (classical) model. Stock rebuilding is expected to be slow, as the species is slow‐growing, has a low natural mortality rate, and mouthbreeds a small amount of large eggs. 相似文献
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158.
Reis SR Sampaio AL Henriques Md Gandini M Azeredo EL Kubelka CF 《Memórias do Instituto Oswaldo Cruz》2007,102(8):983-990
An important cytokine role in dengue fever pathogenesis has been described. These molecules can be associated with haemorrhagic manifestations, coagulation disorders, hypotension and shock, all symptoms implicated in vascular permeability and disease worsening conditions. Several immunological diseases have been treated by cytokine modulation and dexamethasone is utilized clinically to treat pathologies with inflammatory and autoimmune etiologies. We established an in vitro model with human monocytes infected by dengue virus-2 for evaluating immunomodulatory and antiviral activities of potential pharmaceutical products. Flow cytometry analysis demonstrated significant dengue antigen detection in target cells two days after infection. TNF-alpha, IFN-alpha, IL-6 and IL-10 are produced by in vitro infected monocytes and are significantly detected in cell culture supernatants by multiplex microbead immunoassay. Dexamethasone action was tested for the first time for its modulation in dengue infection, presenting optimistic results in both decreasing cell infection rates and inhibiting TNF-alpha, IFN-alpha and IL-10 production. This model is proposed for novel drug trials yet to be applied for dengue fever. 相似文献
159.
Bittar RC Nogueira RS Vieira-Gonçalves R Pinho-Ribeiro V Mattos MS Oliveira-Neto MP Coutinho SG Da-Cruz AM 《Memórias do Instituto Oswaldo Cruz》2007,102(5):625-630
Subclinical or asymptomatic infection is documented in individuals living in endemic areas for leishmaniasis suggesting that the development of an appropriate immune response can control parasite replication and maintain tissue integrity. A low morbidity indicates that intrinsic factors could favor resistance to Leishmania infection. Herein, leishmanial T-cell responses induced in subjects with low susceptibility to leishmaniasis as asymptomatic subjects were compared to those observed in cured cutaneous leishmaniasis (CCL) patients, who controlled the disease after antimonial therapy. All of them have shown maintenance of specific long-term immune responses characterized by expansion of higher proportions of CD4+ as compared to CD8+ Leishmania reactive T-lymphocytes. Asymptomatic subjects had lower indexes of in vitro Leishmania induced lymphoproliferative responses and interferon-gamma (IFN-gamma) production in comparison to CCL patients. On the other hand, interleukin (IL-10) production was much higher in asymptomatics than in CCL, while no differences in IL-5 levels were found. In conclusion, long lived T-cell responses achieved by asymptomatic individuals differed from those who had developed symptomatic leishmaniasis in terms of intensity of lymphocyte activation (proliferation or IFN-gamma) and regulatory mechanisms (IL-10). The absence of the disease in asymptomatics could be explained by their intrinsic ability to create a balance between immunoregulatory (IL-10) and effector cytokines (IFN-gamma), leading to parasite destruction without producing skin tissue damage. The establishment of profiles of cell-mediated immune responses associated with resistance against Leishmania infection is likely to make new inroads into understanding the long-lived immune protection against the disease. 相似文献
160.
Neutrophils activate macrophages for intracellular killing of Leishmania major through recruitment of TLR4 by neutrophil elastase 总被引:5,自引:0,他引:5
Ribeiro-Gomes FL Moniz-de-Souza MC Alexandre-Moreira MS Dias WB Lopes MF Nunes MP Lungarella G DosReis GA 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(6):3988-3994
We investigated the role of neutrophil elastase (NE) in interactions between murine inflammatory neutrophils and macrophages infected with the parasite Leishmania major. A blocker peptide specific for NE prevented the neutrophils from inducing microbicidal activity in macrophages. Inflammatory neutrophils from mutant pallid mice were defective in the spontaneous release of NE, failed to induce microbicidal activity in wild-type macrophages, and failed to reduce parasite loads upon transfer in vivo. Conversely, purified NE activated macrophages and induced microbicidal activity dependent on secretion of TNF-alpha. Induction of macrophage microbicidal activity by either neutrophils or purified NE required TLR4 expression by macrophages. Injection of purified NE shortly after infection in vivo reduced the burden of L. major in draining lymph nodes of TLR4-sufficient, but not TLR4-deficient mice. These results indicate that NE plays a previously unrecognized protective role in host responses to L. major infection. 相似文献