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Souza A.M.,Federal University of Minas Gerais | Assis R.A.,Laboratorio Nacional Agropecuario Pedro Leopoldo Minas Gerais | Horta C.C.,Federal University of Minas Gerais | Siqueira F.F.,Federal University of Minas Gerais | And 9 more authors.
Genetics and Molecular Research | Year: 2010

Epsilon toxin produced by Clostridium perfringens types B and D causes enterotoxemia in sheep, goats and calves. Enterotoxemia can cause acute or superacute disease, with sudden death of the affected animal. It provokes huge economic losses when large numbers of livestock are affected. Therapeutic intervention is challenging, because the disease progresses very rapidly. However, it can be prevented by immunization with specific immunogenic vaccines. We cloned the etx gene, encoding epsilon toxin, into vector pET-11a; recombinant epsilon toxin (rec-ε) was expressed in inclusion bodies and was used for animal immunization. Serum protection was evaluated and cross-serum neutralization tests were used to characterize the recombinant toxin. To analyze the potency of the toxin (as an antigen), rabbits were immunized with 50, 100 or 200 μg recombinant toxin, using aluminum hydroxide gel as an adjuvant. Titers of 10, 30 and 40 IU/mL were obtained, respectively. These titers were higher than the minimum level required by the European Pharmacopoeia (5 IU/mL) and by the USA Code of Federal Regulation (2 IU/mL). This rec-ε is a good candidate for vaccine production against enterotoxemia caused by epsilon toxin of C. perfringens type D. ©FUNPEC-RP.

Nakamura Filho A.,Rede Tematica em Engineering de Materiais REDEMAT | De Almeida A.C.,Rede Tematica em Engineering de Materiais REDEMAT | Riera H.E.,Rede Tematica em Engineering de Materiais REDEMAT | Gouveia V.J.P.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | And 3 more authors.
Materials Research | Year: 2014

Applying the theories of Materials Science and Engineering to describe the composition and hierarchy of microstructures that comprise biological systems could help the search for new materials and results in a deeper insight into evolutionary processes. The layered microstructure that makes up the freshwater bivalve Limnoperna fortunei shell, an invasive specie in Brazil, was investigated utilizing SEM and AFM for the determination of the morphology and organization of the layers; and XRD was used to determine the crystalline phases of the calcium carbonate (CaCO3) present in the shell. The presence of the polymorphs calcite and aragonite were confirmed and the calcite is present only on the external side of the shell. The shell of L. fortunei is composed of two layers of aragonite with distinct microstructures (the aragonite prismatic layer and the aragonite sheet nacreous layer) and the periostracum (a protein layer that covers and protects the ceramic part of the shell). A new morphology of the calcite layer was found, below the periostracum, without defined form, albeit crystalline.

Spadeto Jr. O.,Federal University of Minas Gerais | Spadeto Jr. O.,Centro Universitario Of Vila Velha Uvv | Rodrigues L.B.,Federal University of Minas Gerais | Rodrigues L.B.,State University of Southwest Bahia | And 8 more authors.
Ciencia Rural | Year: 2011

The development of new devices using available and low cost materials may be an useful alternative for the treatment of long bone fractures in large animals. The aim of this study was to evaluate the mechanical strength of young bovine femur with diaphyseal fracture fixed with different polymeric intramedullary nails. Bending and compression tests using a universal machine were carried out in 4 distinct groups of 6 femurs from young calves. In one of the groups bones were intact while in the other three fractured bones were fixed using an intramedullary nail made of polypropylene, polyacetal or polyamide (one for each group). Considering bending and compression tests together, none of the used polymers offered strength to the fractured bones similar to the intact ones. The agreement of this findings with those from previous published in vivo results indicates that the employed ex vivo methods for mechanical assays may be useful in the search of stronger materials to be used in development of new devices.

Campos M.C.S.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Lanzer R.,University of Caxias do Sul | Castro P.T.,Federal University of Ouro Preto
Acta Limnologica Brasiliensia | Year: 2012

Limnoperna fortunei (Dunker, 1857), is an asiatic mussel that arrived in South America in 1991. Since 2004, we have noticed that the advance of this species in the lower Paranaíba River, a tributary of the Upper Paraná River, is slow when compared to the average speed of 240 km/year in the Paraná River (middle and lower course). Aim: The goal of this work is to understand what factors are limiting the spread of L. fortunei in this stretch of the Paranaíba River. Methods: Its occurrence and dispersion were sampled twelve times between March 2006 and November 2007 in the Paranaíba River, including the São Simão hydroelectric reservoir. Physicochemical characteristics of the water were analysed, and a Stream Length-Gradient Index calculated for the study area. Results: Adult mussels were easily found attached to the hulls of barges that travel on this stretch of the Paraná-Tietê waterway and on vessels that were docked in the harbours of grain exporters located in São Simão (GO). However, no larvae or adults were found near the harbours or upstream from them at the São Simão hydroelectric reservoir. The pH and concentration of calcium and dissolved oxygen values among lotic habitats and the reservoir were similar: DO values were close to 7 mg.L-1, the average pH was near 7, average values of total Ca ranged between 4 and 6 mg.L-1 and the chlorophyll-a levels were not restrictive to the mussel. Conclusion: Physical and chemical water parameters show that habitats were suitable for establishment of the mussel. In addition to a low pressure of propagules, this paper proposes some hydrological variables, such as the energy of the fluvial stretches, expressed by the Stream Length-Gradient Index and changes in flow downstream of the dam as barriers to the establishment of the species, discouraging larval settlement, and decreasing survival and recruitment.

Bruxel F.,Federal University of Rio Grande do Sul | Vilela J.M.C.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Andrade M.S.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Malachias T.,Federal University of Minas Gerais | And 4 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2013

Atomic force microscopy image analysis and energy dispersive X-ray diffraction experiments were used to investigate the structural organization of cationic nanoemulsion/oligonucleotide complexes. Oligonucleotides targeting topoisomerase II gene were adsorbed on cationic nanoemulsions obtained by means of spontaneous emulsification procedure. Topographical analysis by atomic force microscopy allowed the observation of the nanoemulsion/oligonucleotide complexes through three-dimensional high-resolution images. Flattening of the oil droplets was observed, which was reduced in the complexes obtained at high amount of adsorbed oligonucleotides. In such conditions, complexes exhibit droplet size in the 600. nm range. The oligonucleotides molecules were detected on the surface of the droplets, preventing their fusion during aggregation. A lamellar structure organization was identified by energy dispersive X-ray diffraction experiments. The presence of the nucleic acid molecules led to a disorganization of the lipid arrangement and an expansion in the lattice spacing, which was proportional to the amount of oligonucleotides added. © 2013 Elsevier B.V.

Filho A.A.M.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Pereira R.A.,Federal University of Ouro Preto | De Sousa C.M.,University BH | Da Silva Araujo F.G.,Federal University of Ouro Preto
65th ABM International Congress, 18th IFHTSE Congress and 1st TMS/ABM International Materials Congress 2010 | Year: 2010

In this work were evaluated recycled hydroxyapatite coatings on 316L stainless steel substrates by plasma thermal aspersion. The hydroxyapatite used was obtained from bovine bone by the hydrothermal method. The samples of hydroxyapatite powders were divided according to their particle size distribution. The adhesion of the powders coating to the substrate was evaluated by assay scratch. The X-ray diffraction techniques and scanning electron microscopy were also used. The results of scratch resistance were between 46N and 63N. Analysis by scanning electron microscopy and x-ray diffraction showed no cracks coatings, single-phase and with few fused particles.

Araujo R.S.,Federal University of Minas Gerais | Fuscaldi L.L.,Federal University of Minas Gerais | Takenaka I.K.T.M.,Federal University of Minas Gerais | Vilela J.M.C.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | And 3 more authors.
Journal of Radioanalytical and Nuclear Chemistry | Year: 2015

Nanocapsules (NCs) of poly-ε-caprolactone (PCL NC) and poly-ε-caprolactone coated with chitosan (CS-PCL NC) loaded with technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) were employed as a model to understand the role of these nanocarriers in the veterinary area. 99mTc-MIBI-NCs and 99mTc-MIBI were administrated by intramammary via in rats. The level of radioactivity in the blood was lower when NCs were employed in all times investigated. The results obtained suggest that NCs could be an alternative method for treatment of intramammary diseases in animals, once the data showed high retention in this tissue, increasing the drug residence time on the target. © 2014, Akadémiai Kiadó, Budapest, Hungary.

Souza C.C.,Federal University of Minas Gerais | Barreto T.O.,Federal University of Minas Gerais | da Silva S.M.,Federal University of Uberlandia | Pinto A.W.J.,Federal University of Minas Gerais | And 4 more authors.
International Journal of Experimental Pathology | Year: 2014

Canine visceral leishmaniasis (CVL) is a severe and fatal systemic chronic inflammatory disease. We investigated the alterations in, and potential associations among, antioxidant enzymes, trace elements and histopathology in CVL. Blood and tissue levels of Cu-Zn superoxide dismutase, catalase and glutathione peroxidase were measured in mixed-breed dogs naturally infected with Leishmania infantum chagasi, symptomatic (n = 19) and asymptomatic (n = 11). Serum levels of copper, iron, zinc, selenium and nitric oxide, and plasma lipid peroxidation were measured. Histological and morphometric analyses were conducted of lesions in liver, spleen and lymph nodes. We found lower blood catalase and glutathione peroxidase activity to be correlated with lower iron and selenium respectively. However, higher activity of Cu-Zn superoxide dismutase was not correlated with the increase in copper and decreased in zinc observed in infected animals compared to controls. Organ tissue was characterized by lower enzyme activity in infected dogs than in controls, but this was not correlated with trace elements. Lipid peroxidation was higher in symptomatic than in asymptomatic and control dogs and was associated with lesions such as chronic inflammatory reaction, congestion, haemosiderin and fibrosis. Systemic iron deposition was observed primarily in the symptomatic dogs showing a higher tissue parasite load. Dogs with symptomatic CVL displayed enhanced LPO and Fe tissue deposition associated with decreased levels of antioxidant enzymes. These results showed new points in the pathology of CVL and might open new treatment perspectives associated with antioxidants and the role of iron in the pathogenesis of CVL. © 2014 The Authors.

Silva A.C.B.,Federal University of Minas Gerais | Costa V.C.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Ardisson J.D.,Brazilian Nuclear Technology Development Center (CDTN) | Magalhaes F.,Federal University of Alfenas | And 2 more authors.
Materials Research Bulletin | Year: 2010

In this work, the single source organometallic precursor Bu4Sn6S6 was impregnated and decomposed on the surface of TiO2 to produce semiconductor composites. 119Sn Mössbauer, Raman and ultra violet/visible spectroscopies, powder X-ray diffraction, temperature programmed reduction and surface area suggest for Sn contents of 1, 5 and 10 wt%, the formation of a highly dispersed unstable SnS phase which is readily oxidized by air at room temperature to form SnO2 on the TiO2 surface. The composite with Sn 30 wt% produced a mixture with the phases SnS/γ-Sn2S3 and SnO2. Photocatalytic experiments with the composites SnXn/TiO2 using the textile dye Drimaren red as a probe molecule showed a first-order reaction with rate constants kabsorbance for the composites with Sn 1 and 5% higher than pure TiO2 which was explained by the formation of the more active photocatalyst composite SnO2/TiO2. © 2009 Elsevier Ltd. All rights reserved.

Meyer S.T.,Fundacao Centro Tecnologico Of Minas Gerais Cetec | Franceschinelli E.V.,Federal University of Goais
Revista Brasileira de Botanica | Year: 2010

The Espinhaço Range in the Minas Gerais State comprises a group of mountains that ranges between the limits of 20°21'56" S and 43°26'02" W (Mariana) and 14°58'54" S and 42°30'10" W (Minas Gerais/Bahia state line). We conducted a floristic survey of vascular plant species associated with wetlands in ten areas, using a 5 × 50 m transect in each area. Fifty three families, 126 genera and 224 species were represented. Families with highest species richness were: Cyperaceae (17.86%), Poaceae (10.27%), Asteraceae (7.14%) Eriocaulaceae (4.91%), and Melastomataceae (4.91%). Cluster analysis showed higher similarity between environments of rivers and lakes geographically closer, but the Mantel test for all areas was not significant (P = 0.17). The large number of unique species influenced the high value of the estimator "Jacknife" (341.9). The São Francisco River basin was the richest in species number (116). Environments sampled showed different plant communities, which reflect their floristic peculiarities.

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