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- Author or Editor: L. Santos x
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Abstract
The role of CD25+ regulatory T cells during the course of Trypanosoma cruzi infection has been previously analyzed, and the bulk of results have shown a limited role for this T cell subpopulation. In this study, we have used an IgM, nondepleting monoclonal antibody (mAb) aiming at blocking interleukin (IL)-2 activity on CD25+ T cells. The administration of this antibody 10 days before infection increased the resistance of outbred Swiss mice to the Colombian strain of T. cruzi. Anti-CD25-treated mice had lower parasitemia and augmented numbers of effector memory T cells. In addition, these animals showed higher numbers of splenic T cells secreting IFN-γ and TNF-α, both cytokines described to be involved in the resistance to T. cruzi infection. The same treatment also increased the numbers of splenic T cells that produced homeostatic and regulatory cytokines, such as IL-2 and IL-10, and CD4+CD25+ T cells. The administration of nondepleting anti-CD25 mAb at the beginning of the chronic phase, when parasites were cleared from the blood, halted the inflammatory process in the heart, without any signs of infection reactivation. These results indicate that nondepleting anti-CD25 monoclonal antibodies may be useful to treat chronic Chagas’ disease.
Forest conversion to anthropogenic uses is a generalized phenomenon throughout tropical Latin America. We evaluated whether patches of secondary forest, which develop relatively rapidly after field abandonment, contribute to conservation of phyllostomid bat assemblages. Our objective was to compare patterns of phyllostomid bat abundance and the structure and composition of phyllostomid bat assemblages across three forest types in the northern neotropics of eastern Mexico. We studied phyllostomid bats within secondary evergreen, primary semi-deciduous, and primary evergreen forests. For each forest type, three representative sites were sampled with mist nets once during the dry season and once during the rainy season for a total of nine sites. Richness, diversity, and assemblage composition patterns were compared among forest types for all phyllostomid species, and for three groups of sensitivity to habitat fragmentation. Abundance of individual species was also compared among forest types. A total of 646 individual bats from 15 species, 11 of which were phyllostomids, were registered. Combining both seasons, more than 250 captures were accomplished at both the primary evergreen and secondary evergreen forests, and only 81 individuals were caught at primary semi-deciduous forests. Overall richness and diversity of species and sensitivity groups were greater in the rainy than the dry season. Richness was greater in secondary evergreen than in primary semi-deciduous forests, and diversity was greatest in the primary evergreen, intermediate in the secondary evergreen, and lowest in the primary semi-deciduous forest. Some overlap in composition was also evident, although there was separation between forest types and seasons. Mean abundances were higher for some species at primary evergreen and secondary evergreen forests, but were threefold lower (though not significantly) in secondary evergreen forests in the dry season for some other species. We also found that primary evergreen forests have the greatest importance for phyllostomids during the dry season. These results suggest that maintenance of secondary evergreen forests, which cover a large proportion of the northeastern Mexican neotropics, would contribute to the conservation of diverse tropical bat communities. Therefore, large areas of this forest type should necessarily be incorporated in the landscape.
The objective of this study was to evaluate the acceptance of fermented anchovy (Engraulis anchoita) by consumers aged 18–67 (n=100) from two experiments, first using preference test and then by acceptance of formulation preference. Anchovy fillets were fermented with added NaCl and glucose with 4 different treatments: A (NaCl 1% and glucose 4%), B (NaCl 1% and glucose 6%), C (NaCl 1.5% and glucose 4%), and D (NaCl 1.5% and glucose 6% glucose). At first, the preference of fermented anchovy fillets with samples prepared in the form of pizza was assessed by applying a preference ranking test to 75 consumers. The results indicated the sample with 1% NaCl and 6% glucose as the preferred (P>0.05). Later in the second stage, the preferred fermented fillet was subjected to acceptance by 100 consumers who have the consumption habit of such product by using a hedonic scale of 9 points. The results indicated an acceptance rate of 79.8%. This work aimed to call attention to the importance of the acceptance of this food.
Abstract
This study attempted to optimize pectin extraction from queen pineapple (Qp) peels using microwave-assisted method. A three-factor factorial experimental design was employed to test the interaction of moisture content of pineapple peel, pH of the citric acid solution and extraction time. The three-way interaction among the factors has a significant effect on pectin recovery. Two-way interaction between moisture content and pH level, as well as pH level and extraction time caused significant difference in the pectin recovery. Pectin recovery increases with lower moisture content while longer extraction time does not significantly increase pectin recovery. The optimum combination of the parameters is 12% moisture content, pH level 2 of the citric acid solution, and extraction duration of 2 min, which yielded 1.01 ± 0.01% pectin recovery. This is lower than the results from previous studies on pineapple with 3.88–13.06% pectin recovery using acid extraction method. Hence further optimization is recommended.
