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Belo Horizonte, Brazil

Reis G.L.,Federal University of Minas Gerais | Lana A.M.Q.,Federal University of Minas Gerais | Mauricio R.M.,Ezequiel Dias Foundation FUNED | Lana R.M.Q.,Federal University of Uberlandia | And 3 more authors.
Plant and Soil | Year: 2010

Silvopastoral systems (SPS) have been suggested as an approach to reduce pasture degradation and, consequently, reduce the deforestation of new areas in the Brazilian cerrado (savanna). This study assessed the contribution of trees to soil fertility in a silvopastoral system in Lagoa Santa, Minas Gerais State, Brazil, 19° 35′ 36″ S, 43° 51′ 56″ W; altitude 747 m. The SPS has developed since 1984, through the use of natural regeneration of the native species Zeyheria tuberculosa Vell. Bur., with a density of 160 trees ha-1. The forage component of the system was Brachiaria brizantha cv. Marandu. The control treatment was a pasture adjacent to SPS with the same forage but without the influence of trees. In 2005, the litterfall of trees (leaves, fruits, and stems) was collected monthly, and the dry matter yield and nutrient content were measured. Soil profile samples were collected in February 2006. The litterfall of trees represented considerable inputs of nitrogen (N), potassium (K), and calcium (Ca2+). In the soil, organic matter (OM) and K reduced with depth. At this planting density, this tree species contributed mainly to amelioration of soil acidity, in the 0-2 cm layer and/or in the profile as a whole. In contrast, there were no significant differences in N, P, and K content of the control and SPS soil. This can be related to the high C/N and lignin/N ratios of the litter inputs. Agroforestry systems are complex and the site specific interactions among the components (tree, forage, and animal) must be understood to develop locally adapted systems and optimize productive efficiency. Consequently simple prescriptions for the implementation of SPS by land managers are unlikely. © Springer Science+Business Media B.V. 2009. Source

Santos M.H.,Federal University of Vales do Jequitinhonha and Mucuri | Silva R.M.,Federal University of Vales do Jequitinhonha and Mucuri | Dumont V.C.,Federal University of Vales do Jequitinhonha and Mucuri | Neves J.S.,Federal University of Vales do Jequitinhonha and Mucuri | And 2 more authors.
Materials Science and Engineering C | Year: 2013

Bovine pericardium is widely used as a raw material in bioengineering as a source of collagen, a fundamental structural molecule. The physical, chemical, and biocompatibility characteristics of these natural fibers enable their broad use in several areas of the health sciences. For these applications, it is important to obtain collagen of the highest possible purity. The lack of a method to produce these pure biocompatible materials using simple and economically feasible techniques presents a major challenge to their production on an industrial scale. This study aimed to extract, purify, and characterize the type I collagen protein originating from bovine pericardium, considered to be an abundant tissue resource. The pericardium tissue was collected from male animals at slaughter age. Pieces of bovine pericardium were enzymatically digested, followed by a novel protocol developed for protein purification using ion-exchange chromatography. The material was extensively characterized by electrophoresis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and infrared spectroscopy. The results showed a purified material with morphological properties and chemical functionalities compatible with type I collagen and similar to a highly purified commercial collagen. Thus, an innovative and relatively simple processing method was developed to extract and purify type I collagen from bovine tissue with potential applications as a biomaterial for regenerative tissue engineering. © 2012 Elsevier B.V. Source

Zurita-Turk M.,Federal University of Minas Gerais | del Carmen S.,CONICET | Santos A.C.G.,Federal University of Minas Gerais | Pereira V.B.,Federal University of Minas Gerais | And 7 more authors.
BMC Biotechnology | Year: 2014

Background: Inflammatory bowel diseases (IBD) are intestinal disorders characterized by inflammation in the gastrointestinal tract. Interleukin-10 is one of the most important anti-inflammatory cytokines involved in the intestinal immune system and because of its role in downregulating inflammatory cascades, its potential for IBD therapy is under study. We previously presented the development of an invasive strain of Lactococcus lactis (L. lactis) producing Fibronectin Binding Protein A (FnBPA) which was capable of delivering, directly to host cells, a eukaryotic DNA expression vector coding for IL-10 of Mus musculus (pValac:il-10) and diminish inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse model of intestinal inflammation. As a new therapeutic strategy against IBD, the aim of this work was to evaluate the therapeutic effect of two L. lactis strains (the same invasive strain evaluated previously and the wild-type strain) carrying the therapeutic pValac:il-10 plasmid in the prevention of inflammation in a dextran sodium sulphate (DSS)-induced mouse model.Results: Results obtained showed that not only delivery of the pValac:il-10 plasmid by the invasive strain L. lactis MG1363 FnBPA+, but also by the wild-type strain L. lactis MG1363, was effective at diminishing intestinal inflammation (lower inflammation scores and higher IL-10 levels in the intestinal tissues, accompanied by decrease of IL-6) in the DSS-induced IBD mouse model.Conclusions: Administration of both L. lactis strains carrying the pValac:il-10 plasmid was effective at diminishing inflammation in this murine model of experimental colitis, showing their potential for therapeutic intervention of IBD. © 2014 Zurita-Turk et al. Source

Camargo D.R.A.,Oswaldo Cruz Foundation | Pais F.S.,Genomics and Computational Biology Group | Pais F.S.,Center for Excellence in Bioinformatics | Volpini C.,Genomics and Computational Biology Group | And 3 more authors.
BMC Genomics | Year: 2015

Background: Ninety-two Streptococcus pneumoniae serotypes have been described so far, but the pneumococcal conjugate vaccine introduced in the Brazilian basic vaccination schedule in 2010 covers only the ten most prevalent in the country. Pneumococcal serotype-shifting after massive immunization is a major concern and monitoring this phenomenon requires efficient and accessible serotyping methods. Pneumococcal serotyping based on antisera produced in animals is laborious and restricted to a few reference laboratories. Alternatively, molecular serotyping methods assess polymorphisms in the cps gene cluster, which encodes key enzymes for capsular polysaccharides synthesis in pneumococci. In one such approach, cps-RFLP, the PCR amplified cps loci are digested with an endonuclease, generating serotype-specific fingerprints on agarose gel electrophoresis. Methods: In this work, in silico and in vitro approaches were combined to demonstrate that XhoII is the most discriminating endonuclease for cps-RFLP, and to build a database of serotype-specific fingerprints that accommodates the genetic diversity within the cps locus of 92 known pneumococci serotypes. Results: The expected specificity of cps-RFLP using XhoII was 76% for serotyping and 100% for serogrouping. The database of cps-RFLP fingerprints was integrated to Molecular Serotyping Tool (MST), a previously published web-based software for molecular serotyping. In addition, 43 isolates representing 29 serotypes prevalent in the state of Minas Gerais, Brazil, from 2007 to 2013, were examined in vitro; 11 serotypes (nine serogroups) matched the respective in silico patterns calculated for reference strains. The remaining experimental patterns, despite their resemblance to their expected in silico patterns, did not reach the threshold of similarity score to be considered a match and were then added to the database. Conclusion: The cps-RFLP method with XhoII outperformed the antisera-based and other molecular serotyping methods in regard of the expected specificity. In order to accommodate the genetic variability of the pneumococci cps loci, the database of cps-RFLP patterns will be progressively expanded to include new variant in vitro patterns. The cps-RFLP method with endonuclease XhoII coupled with MST for computer-assisted interpretation of results may represent a relevant contribution to the real time detection of changes in regional pneumococci population diversity in response to mass immunization programs. © 2015 Camargo et al.; licensee BioMed Central Ltd. Source

Gabriel L.M.,Brazilian Nuclear Technology Development Center (CDTN) | Sanchez E.F.,Ezequiel Dias Foundation FUNED | Silva S.G.,Ezequiel Dias Foundation FUNED | dos Santos R.G.,Brazilian Nuclear Technology Development Center (CDTN) | dos Santos R.G.,Brazil National Institute of Science and Technology of Molecular Medicine INCT MM
Journal of Venomous Animals and Toxins Including Tropical Diseases | Year: 2012

Although it has been demonstrated that venoms and toxins from some snakes are able to influence the growth of tumor cells, few antitumoral compounds from Bothrops leucurus venom have been characterized. Leucurolysin-B (leuc-B) is a metalloproteinase class P-III isolated from B. leucurus which possesses an ECD-disintegrin domain. Both ECD-disentegrin and RGD-disintegrin are able to bind to cell surface integrins and inhibit their adherence to their natural ligands. In the present study, the potential efficacy and the cytotoxic effects of leuc-B on glioblastoma, breast cancer and melanoma cell lines were analyzed. The effect of leuc-B on cancer cell survival was evaluated and its 50% inhibitory concentration (IC 50) was determined. Morphological alterations were monitored by contrast phase and fluorescent microscopy. The results demonstrated that leuc-B has potent cytotoxic effect in a micromolar range against all evaluated cancer cell lines. Morphologically, dying cells showed fragmentation, condensation of their contents concomitant with shrinkage and appearance of vacuoles. This study reports for the first time the cytotoxic effect of leuc-B from B. leucurus snake venom on tumor cells. © CEVAP 2012. Source

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