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101.
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
102.
A variety of Krebs cycle intermediaries has been shown to possess antioxidant properties in different in vivo and in vitro systems. Here we examined whether citrate, succinate, malate, oxaloacetate, fumarate and alpha-ketoglutarate could modulate malonate-induced thiobarbituric acid-reactive species (TBARS) production in rat brain homogenate. The mechanisms involved in their antioxidant activity were also determined using two analytical methods: 1) a popular spectrophotometric method (Ohkawa, H., Ohishi, N., Yagi, K., 1979. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Analytical Biochemistry 95, 351-358.) and a high performance liquid chromatographic (HPLC) procedure (Grotto, D., Santa Maria, L. D., Boeira, S., Valentini, J., Char?o, M. F., Moro, A. M., Nascimento, P. C., Pomblum, V. J., Garcia, S. C., 2006. Rapid quantification of malondialdehyde in plasma by high performance liquid chromatography-visible detection. Journal of Pharmaceutical and Biomedical Analysis 43, 619-624.). Citrate, malate, and oxaloacetate reduced both basal and malonate-induced TBARS production. Their effects were not changed by pre-treatment of rat brain homogenates at 100 degrees C for 10 min. alpha-Ketoglutarate increased basal TBARS without changing malonate-induced TBARS production in fresh and heat-treated homogenates. Succinate reduced basal--without altering malonate-induced TBARS production. Its antioxidant activity was abolished by KCN or heat treatment. Fumarate reduced malonate-induced TBARS production in fresh homogenates; however, its effect was completely abolished by heat treatment. There were minimal differences among the studied methods. Citrate, oxaloacetate, malate, alpha-ketoglutarate and malonate showed iron-chelating activity. We suggest that antioxidant properties of citrate, malate and oxaloacetate were due to their ability to cancel iron redox activity by forming inactive complexes, whereas alpha-ketoglutarate and malonate pro-oxidant activity can be due to formation of active complexes with iron. In contrast, succinate and fumarate antioxidant activity was probably due to some enzymatic system. 相似文献
103.
Expression of LH receptor mRNA splice variants in bovine granulosa cells: changes with follicle size and regulation by FSH in vitro 总被引:1,自引:0,他引:1
Nogueira MF Buratini J Price CA Castilho AC Pinto MG Barros CM 《Molecular reproduction and development》2007,74(6):680-686
In cattle, most evidence suggests that granulosa cells express LH receptors (LHR) after (or as) the follicle becomes dominant, however there is some suggestion that granulosa cells from smaller pre-dominant follicles may express several LHR mRNA splice variants. The objective of this study was to measure LHR expression in bovine follicles of defined size and steroidogenic ability, and in granulosa cells from small follicles (<6 mm diameter) undergoing differentiation in vitro. Semiquantitative RT-PCR demonstrated that LHR mRNA was undetectable in granulosa cells of follicles <7 mm diameter (nondominant follicles), and increased with follicle diameter in follicles >7 mm diameter. Splice variants with deletions of exon 10 and part of exon 11 were detected as previously described, and we detected a novel splice variant with a deletion of exon 3. Cultured granulosa cells contained LHR mRNA, but with significantly greater amounts of variants with deletions of exon 10 and/or exon 11 compared with cells from dominant follicles. FSH increased the abundance of some but not all LHR mRNA splice variants in cultured granulosa cells. The addition of LH to cultured cells did not increase progesterone secretion, despite the presence of LHR mRNA. Collectively, these data suggest that granulosa cells do not acquire functional LHR until follicle dominance occurs. 相似文献
104.
Gabriel C. Costa Cristiano Nogueira Ricardo B. Machado Guarino R. Colli 《Diversity & distributions》2007,13(6):714-724
We investigate patterns of species richness of squamates (lizards, snakes, and amphisbaenians) in the Brazilian Cerrado, identifying areas of particularly high richness, and testing predictions of large‐scale richness hypotheses by analysing the relationship between species richness and environmental climatic variables. We used point localities from museum collections to produce maps of the predicted distributions for 237 Cerrado squamate species, using niche‐modelling techniques. We superimposed distributions of all species on a composite map, depicting richness across the ecosystem. Then, we performed a multiple regression analysis using eigenvector‐based spatial filtering (Principal Coordinate of Neighbour Matrices) to assess environmental–climatic variables that are best predictors of species richness. We found that the environmental–climatic and spatial filters multiple regression model explained 78% of the variation in Cerrado squamate richness (r2 = 0.78; F = 32.66; P < 0.01). Best predictors of species richness were: annual precipitation, precipitation seasonality, altitude, net primary productivity, and precipitation during the driest quarter. A model selection approach revealed that several mechanisms related to the different diversity hypothesis might work together to explain richness variation in the Cerrado. Areas of higher species richness in Cerrado were located mainly in the south‐west, north, extreme east, and scattered areas in the north‐west portions of the biome. Partitioning of energy among species, habitat differentiation, and tolerance to variable environments may be the primary ecological factors determining variation in squamate richness across the Cerrado. High richness areas in northern Cerrado, predicted by our models, are still poorly sampled, and biological surveys are warranted in that region. The south‐western region of the Cerrado exhibits high species richness and is also undergoing high levels of deforestation. Therefore, maintenance of existing reserves, establishment of ecological corridors among reserves, and creation of new reserves are urgently needed to ensure conservation of species in these areas. 相似文献
105.
Nogueira FC Gonçalves EF Jereissati ES Santos M Costa JH Oliveira-Neto OB Soares AA Domont GB Campos FA 《Plant cell reports》2007,26(8):1333-1343
Using a combination of two-dimensional gel electrophoresis protein mapping and mass spectrometry analysis, we have established
proteome reference maps of embryogenic cell suspensions of cowpea (Vigna unguiculata). The cell suspensions were generated from young primary leaves and contained basically pro-embryogenic masses, which enabled
us to dissect their proteome composition while eliminating the complexity of too many cell types. Over 550 proteins could
reproducibly be resolved over a pI range of 3–10. A total of 128 of the most abundant protein spots were excised, digested
in-gel with trypsin and analyzed by tandem mass spectrometry. This enabled the identification of 67 protein spots. Two of
the most abundant proteins were identified as a chitinase and as a ribonuclease belonging to the family of PR-4 and PR-10
proteins, respectively. The expression of the respective genes was confirmed by RT-PCR and the pattern of deposition of the
PR-10 protein in cell suspensions as well as in developing cowpea seeds, roots, shoots and flowers were determined by Western
blot experiments, using synthetic antibodies raised against a 14-amino acid synthetic peptide located close to the C-terminal
region of the PR-10 protein. 相似文献
106.
Amarildo Emanuel Correia Jordão Bruno Cogliati Bernard Ernesto Jensch-Junior Leandro Nogueira Pressinotti Osório Miguel Parra Francisco Javier Hernandez-Blazquez José Roberto Machado Cunha da Silva 《Polar Biology》2007,30(3):387-390
The Notothenia coriiceps liver is commonly infected with parasites, reducing the hepatic mass and inducing the regeneration. In order to better understand
the effect of nutrient influx on hepatic regeneration at 0°C, a usual mammal hepatotrophic factor (HF) solution was injected
into ten fish (HF group), while ten fish were injected with saline solution (control), twice a day, for 15 days. The liver
and carcass weight were measured, and samples were obtained for histological studies. The HF group presented a higher liver/carcass
weight (62.5%) than control group. This increase in liver mass was due mainly to hepatocytes hypertrophy, including nuclear
size increase and cytoplasmic inclusions of glycogen. Hyperplasia is also observed, although to a lesser extent. The hepatic
reaction to HF in Antarctic fish was here demonstrated for the first time, helping to understand the liver response to seasonal
nutrient. 相似文献
107.
Length–weight relationships of fish from Madeira River,Brazilian Amazon,before the construction of hydropower plants 下载免费PDF全文
A. Cella‐Ribeiro M. Hauser L. D. Nogueira C. R. C. Doria G. Torrente‐Vilara 《Zeitschrift fur angewandte Ichthyologie》2015,31(5):939-945
Length–weight relationships (LWRs) are presented for 112 freshwater fish species representing 23 families and five orders captured in the Madeira River, the largest white‐water river tributary of the Amazon River. The allometry coefficient (b) of the LWR (Wt = aSLb) ranged from 2.446 to 3.856 with a median value of 3.102. Eight new LWR records are presented for Amazonian species as information for FishBase. LWRs in the present study provide historical data on a and b coefficients prior to the damming of the Madeira River in November 2011, allowing comparison estimates of predicted future population parameters as influenced by human intervention. 相似文献
108.
109.
Alex Pauvolid-Corrêa Raquel Soares Juliano Zilca Campos Jason Velez Rita Maria Ribeiro Nogueira Nicholas Komar 《Memórias do Instituto Oswaldo Cruz》2015,110(1):125-133
The Pantanal hosts diverse wildlife species and therefore is a hotspot for arbovirus
studies in South America. A serosurvey for Mayaro virus (MAYV), eastern (EEEV),
western (WEEV) and Venezuelan (VEEV) equine encephalitis viruses was conducted with
237 sheep, 87 free-ranging caimans and 748 equids, including 37 collected from a
ranch where a neurologic disorder outbreak had been recently reported. Sera were
tested for specific viral antibodies using plaque-reduction neutralisation test. From
a total of 748 equids, of which 264 were immunised with vaccine composed of EEEV and
WEEV and 484 had no history of immunisation, 10 (1.3%) were seropositive for MAYV and
two (0.3%) for VEEV using criteria of a ≥ 4-fold antibody titre difference. Among the
484 equids without history of immunisation, 48 (9.9%) were seropositive for EEEV and
four (0.8%) for WEEV using the same criteria. Among the sheep, five were sero-
positive for equine encephalitis alphaviruses, with one (0.4%) for EEEV, one (0.4%)
for WEEV and three (1.3%) for VEEV. Regarding free-ranging caimans, one (1.1%) and
three (3.4%), respectively, had low titres for neutralising antibodies to VEEV and
undetermined alphaviruses. The neurological disorder outbreak could not be linked to
the alphaviruses tested. Our findings represent strong evidence that MAYV and all
equine encephalitis alphaviruses circulated in the Pantanal. 相似文献