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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

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. Source

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

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. Source

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. Source

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

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. Source

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

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. Source

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