1,049 research outputs found

    Inhibition of enterotoxigenic Escherichia Coli (ETEC) adhesion to caco-2 cells by human milk and its immunoglobulin and non-immunoglobulin fractions.

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    Enterotoxigenic Escherichia coli (ETEC) is the most common cause of diarrhea in children in developing countries and among travelers to ETEC endemic areas. ETEC diarrhea is caused by colonization of the small intestine mediated by colonization factor (CF) antigens, and subsequent elaboration of enterotoxins. Breast feeding has been related to protection against enteric infections. The protective effect of human milk can be ascribed to its immunoglobulin content, specially secretory immunoglobulin A (sIgA), and to nonimmunoglobulin components such as free oligosaccharides, glycoproteins and glycolipids. In this study we investigated the effect of whole human milk and its fractions immunoglobulin and non-immunoglobulin on the adherence of ETEC strains possessing different CFs to Caco-2 cells, as well as the ability of sIgA and free secretory component (fSC) to bind to bacterial superficial proteins. Pooled human milk from three donors were fractionated by gel filtration and analyzed by SDS-PAGE. Our results revealed that whole human milk and its proteins fractions, containing sIgA and fSC, inhibited adhesion ETEC strains harboring different colonization factors antigens. We also verified that sIgA and fSC, using immunoblotting and immunogold labeling assays, bound to some fimbrial proteins and other material present in bacterial surface. Our findings suggest that whole human milk and its fractions may contribute to protection against ETEC infections by blocking bacterial adhesion mediated by different colonization antigens

    Making Forest Data Fair and Open

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    Los datos sobre los bosques tropicales tienen una gran demanda. Pero las mediciones forestales sobre el terreno son difíciles de sustentar y las personas que las realizan están en gran desventaja con respecto a los que las utilizan. Se propone un nuevo enfoque para datos forestales que se centre en las necesidades de los creadores de los datos y garantice que los usuarios y los financiadores contribuyan adecuadamente.Revisión por pares

    Safety and Immunogenicity of an In Vivo Muscle Electroporation Delivery System for DNA-hsp65 Tuberculosis Vaccine in Cynomolgus Monkeys

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    A Bacille Calmette–Guérin (BCG) is still the only licensed vaccine for the prevention of tuberculosis, providing limited protection against Mycobacterium tuberculosis infection in adulthood. New advances in the delivery of DNA vaccines by electroporation have been made in the past decade. We evaluated the safety and immunogenicity of the DNA-hsp65 vaccine administered by intramuscular electroporation (EP) in cynomolgus macaques. Animals received three doses of DNA-hsp65 at 30-day intervals. We demonstrated that intramuscular electroporated DNA-hsp65 vaccine immunization of cynomolgus macaques was safe, and there were no vaccine-related effects on hematological, renal, or hepatic profiles, compared to the pre-vaccination parameters. No tuberculin skin test conversion nor lung X-ray alteration was identified. Further, low and transient peripheral cellular immune response and cytokine expression were observed, primarily after the third dose of the DNA-hsp65 vaccine. Electroporated DNA-hsp65 vaccination is safe but provides limited enhancement of peripheral cellular immune responses. Preclinical vaccine trials with DNA-hsp65 delivered via EP may include a combination of plasmid cytokine adjuvant and/or protein prime–boost regimen, to help the induction of a stronger cellular immune response

    Sugarcane Straw Blanket Management Effects on Plant Growth, Development, and Yield in Southeastern Brazil

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    In Brazilian sugarcane (Saccharum spp.) production systems, the practice of moving harvesting residue from row to inter-row positions (i.e., raking) has increased in response to producer concerns over the potential negative effects of sugarcane straw on crop establishment and stalk yield. Despite increasing adoption among sugarcane farmers, the impacts of straw raking practices on plant growth and yield remain unclear. A 2-yr experiment that included both dry and wet seasons was conducted at two sites in southeastern Brazil to evaluate straw management strategy effects on plant tillering, phytomass accumulation, plant nutritional status, and stalk yield. The experiments were established at the Bom Retiro mill and the Univalem mill. Experimental treatments included raking straw to inter-rows (raked), total straw removal (bare soil), and no straw removal (straw cover). Raked and bare soil treatments improved plant tillering but did not influence final plant population. Straw management had a slight effect on phytomass accumulation. Reduction of phytomass yield was observed from the first to the second ratoon during both seasons at both sites. At Bom Retiro, phytomass yield decreased 37% for stands established during the dry season and 19% for stands established during the wet season. At Univalem, phytomass yield decreased 20% for stands established during the dry season and 30% for stands established during the wet season. Retaining straw in the field (regardless of treatment) increased leaf tissue P content but not stalk yield. Raking straw from row to interrow positions at these locations in southeastern Brazil had no benefit on sugarcane yield but may result in soil compaction and higher production costs over time

    Contributions of C 3 and C 4 plants to higher trophic levels in an Amazonian savanna

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    Abstract We studied the energy¯ow from C 3 and C 4 plants to higher trophic levels in a central Amazonian savanna by comparing the carbon stable-isotope ratios of potential food plants to the isotope ratios of species of dierent consumer groups. All C 4 plants encountered in our study area were grasses and all C 3 plants were bushes, shrubs or vines. Dierences in d 13 C ratios among bushes (" x = A30.8, SD = 1.2), vines (" x = A30.7, SD = 0.46) and trees (" x = A29.7, SD = 1.5) were small. However the mean d 13 C ratio of dicotyledonous plants (" x = A30.4, SD = 1.3) was much more negative than that of the most common grasses (" x = A13.4, SD = 0.27). The insect primary consumers had d 13 C ratios which ranged from a mean of A29.5 (SD = 0.47) for the grasshopper Tropidacris collaris to a mean of A14.7 (SD = 0.56) for a termite (Nasutitermes sp.), a range similar to that of the vegetation

    Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

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    The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

    Controlled synthesis and structure characterization of a new fluconazole polymorph using analytical techniques and multivariate method

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    In the crystallization and search for higher multicomponent forms of fluconazole (FLZ), a metastable FLZ polymorph (concomitant) that manifests in the same crystallization system and transforms into the stable FLZ form (II) after the lyophilization process was observed. In this report, we demonstrated and showed how this FLZ polymorph 10 (Mw = 306.79 g/mol) of the monoclinic C2 space group was detected and reproduced through a controlled lyophilized experiment, and modeled differentiation between vibrational and absorption modes of FLZ functionalities like C=O, OH, –CH2 and –NH. The FLZ polymorph shows strong O–H···N and weak C−H···X (X = N, and F) hydrogen bond and the presence of pi-pi bond interactions in the overlapping triazole rings. The combination of vibrational spectroscopic techniques (Raman/FT-IR) and principal component analysis (PCA) aid the development of important models for polymorph screening and identification. In addition, X-ray diffraction (powder and single crystal) techniques support the polymorph characterization and structure depiction. The PCA models and X-ray diffraction analyses confirmed the newness of FLZ polymorph 10, and further solid-state characterization using thermal techniques (DSC and TGA) affirmed its uniqueness and novelty. Finally, the thermal stability and solubility studies on the new FLZ polymorph were determined to understand its structure properties and compare these with previously reported polymorphs of FLZ
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