Belo Horizonte, Brazil
Belo Horizonte, Brazil

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Miaw C.S.W.,Federal University of Minas Gerais | Amancio G.C.S.,Ezequiel Dias Foundation FUNED | Rocha V.N.,Ezequiel Dias Foundation FUNED | Madeira J.E.G.C.,Ezequiel Dias Foundation FUNED | Souza S.V.C.,Federal University of Minas Gerais
Quality Assurance and Safety of Crops and Foods | Year: 2017

Considering expansion of genetically modified organisms and the basic principle of consumers' right to access information about products, legislations of several countries establish a limit for labelling transgenic food. Qualitative tests based on the polymerase chain reaction (PCR) have been recommended. However, validation of qualitative methods is still a critical point in the quality management of food analysis laboratories. A screening method for the detection of Roundup Ready (RR) soy in soybeans by nested PCR was validated by a novel qualitative approach, in a single-laboratory, considering all fundamental parameters for an adequate evaluation of fitness for purpose. Blank samples of soybeans and formulations containing 0.001 to 1% of RR soy were analysed. Agarose gel electrophoresis and fluorimetry techniques were compared in terms of the quantification of extracted DNA. False-positive rate obtained was 0%, with selectivity and reliability rates of 100.0% for both techniques. Sensitivity and reliability rates varied between 23.3 and 100.0% (agarose gel) and between 30.0 and 100.0% (fluorimetry), respectively. Levels above 0.030% presented 100.0% positive results. Unreliable regions were estimated by non-linear models, and the calculated detection limits were 0.0067 and 0.0047%, for agarose gel electrophoresis and fluorimetry, respectively. Accordance and concordance values of 1.0 were obtained for levels near the regulated limit. The method was considered fit for screening purposes. Analysis of commercial samples demonstrated the applicability of the method and the compliance with Brazilian legislation. © 2016 Wageningen Academic Publishers.

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.

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.

Pimenta-Martins M.G.R.,State University of Ceará | Furtado R.F.,Embrapa Tropical Agroindustry | Heneine L.G.D.,Ezequiel Dias Foundation FUNED | Dias R.S.,Ezequiel Dias Foundation FUNED | And 2 more authors.
Journal of Microbiological Methods | Year: 2012

This paper reports a novel electrochemical immunosensor for the sensitive detection of staphylococcal enterotoxin A (SEA) based on self-assembly monolayer (SAM) and protein A immobilization on gold electrode. Three different methods of protein A immobilization were tested: physical adsorption, cross-linking using glutaraldehyde and covalent binding after activation with N-hydroxysuccinimide (NHS)/N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) on cysteamine-modified gold electrode. The EDC/NHS method for protein A immobilization was selected to lead development of the biosensor. The coating steps of the surface modification were characterized by cyclic voltammetry and the biosensor response by chronoamperometry. The advantages of the immunosensor were exposed in its high sensitivity and specificity. The proposed amperometric immunosensor was successfully used for determination of SEA in contaminated and non-contaminated cheese samples with excellent responses. © 2012 Elsevier B.V.

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.

Araujo H.F.,Ezequiel Dias Foundation Funed
Canadian journal of microbiology | Year: 2012

Vaccination is the most promising strategy to reduce the incidence of pneumococcal infection. Although there are vaccines available, all of them are based on polysaccharide antigens (conjugated or not). In addition to their high cost, those vaccines do not cover all serotypes. To overcome these hindrances, we evaluated the immunogenicity and the protective efficacy of the S9 ribosomal protein of Streptococcus pneumoniae with the aim of developing a protein-based vaccine in the future. The gene encoding the S9 ribosomal protein was cloned in pET21-a expression vector, and the recombinant S9 protein was used to immunize mice. Significantly higher levels of anti-S9 immunoglobulin G were achieved (with predominance of immunoglobulin G1) in comparison with the control. Antibodies elicited against S. pneumoniae protein extract in rabbit recognized the recombinant S9 protein by Western blot, thus demonstrating its immunogenicity. Moreover, mice immunized with recombinant S9 protein and challenged with a virulent strain of S. pneumoniae presented a significant reduction of bacteremia after 24 h of infection as compared with the control. However, in the S9-immunized mice the onset of death was insignificantly delayed, but all of them died by the fourth day postinfection.

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.

de Alvarenga Mudadu M.,Embrapa Southeast Livestock | Carvalho V.,Ezequiel Dias Foundation Funed | Leclercq S.Y.,Ezequiel Dias Foundation Funed
Applied Biochemistry and Biotechnology | Year: 2015

Reverse vaccinology strategies have already been applied to a variety of microorganisms and have contributed significantly to vaccine development. However, most of the studies focused on an individual organism or on proteins with signature sequence motifs commonly found in known secreted proteins from bacteria. In this work, we applied a reverse vaccinology strategy based on conservation, virulence, and nonclassically surface exposure criterions to identify potential antigens in two microorganisms with significant degree of genomic plasticity among isolates (Streptococcus pneumoniae and Leptospira spp.), which imposes a major limitation to the production of a multistrain component vaccine. PSORTb 3.0.2 was run to predict the subcellular localization of the proteins. OrthoMCL was run to identify groups of the most conserved proteins between strains. Virulence prediction was done for the most conserved proteins, and SecretomeP was run to predict the nonclassically secreted proteins among the potential virulence factors. Based on the above criteria, we identified 37 proteins conserved between 16 genomes of S. pneumoniae and 12 proteins conserved between 5 leptospiral genomes as potential vaccine candidates. © 2015, Springer Science+Business Media New York.

PubMed | Ezequiel Dias Foundation FUNED
Type: | Journal: The journal of venomous animals and toxins including tropical diseases | Year: 2016

The blood plasma of numerous snake species naturally comprises endogenous phospholipase A

PubMed | Ezequiel Dias Foundation FUNED, Institute of Education and Research Santa Casa Belo Horizonte Laboratory of Toxins, Federal University of Minas Gerais and State University of Montes Claros
Type: Journal Article | Journal: Toxins | Year: 2016

The in vivo neuroprotective effect of PhTx3-4, a spider toxin N-P/Q calcium channel blocker, was studied in a rat model of NMDA-induced injury of the retina. NMDA (N-Methyl-D-Aspartate)-induced retinal injury in rats reduced the b-wave amplitude by 62% 3.6%, indicating the severity of the insult. PhTx3-4 treatment increased the amplitude of the b-wave, which was almost equivalent to the control retinas that were not submitted to injury. The PhTx3-4 functional protection of the retinas recorded on the ERG also was observed in the neuroprotection of retinal cells. NMDA-induced injury reduced live cells in the retina layers and the highest reduction, 84%, was in the ganglion cell layer. Notably, PhTx3-4 treatment caused a remarkable reduction of dead cells in the retina layers, and the highest neuroprotective effect was in the ganglion cells layer. NMDA-induced cytotoxicity of the retina increased the release of glutamate, reactive oxygen species (ROS) production and oxidative stress. PhTx3-4 treatment reduced glutamate release, ROS production and oxidative stress measured by malondialdehyde. Thus, we presented for the first time evidence of in vivo neuroprotection from NMDA-induced retinal injury by PhTx3-4 (-ctenitoxin-Pn3a), a spider toxin that blocks N-P/Q calcium channels.

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