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Belo Horizonte, Brazil

Naumann G.B.,Research and Development Center | Silva L.F.,Research and Development Center | Silva L.,Research and Development Center | Faria G.,Research and Development Center | And 9 more authors.
Biochimica et Biophysica Acta - General Subjects | Year: 2011

Background: Multifunctional l-amino acid oxidases (LAAOs) occur widely in snake venoms. Methods: The l-AAO from Bothrops leucurus (Bl-LAAO) venom was purified using a combination of molecular exclusion and ion-exchange chromatographies. We report some biochemical features of Bl-LAAO associated with its effect on platelet function and its cytotoxicity. Results: Bl-LAAO is a 60 kDa monomeric glycoprotein. Its N-terminal sequence shows high homology to other members of the snake-venom LAAO family. Bl-LAAO catalyzes oxidative deamination of l-amino acids with the generation of H2O2. The best substrates were: l-Met, l-Norleu, l-Leu, l-Phe and l-Trp. The effects of snake venom LAAOs in hemostasis, especially their action on platelet function remain largely unknown. Bl-LAAO dose-dependently inhibited platelet aggregation of both human PRP and washed platelets. Moreover, the purified enzyme exhibited a killing effect in vitro against Leishmania sp., promastigotes, with a very low EC50 of 0.07 μM. Furthermore, the cytotoxicity of Bl-LAAO was observed in the stomach cancer MKN-45, adeno carcinoma HUTU, colorectal RKO and human fibroblast LL-24 cell lines. The enzyme released enough H 2O2 in culture medium to induce apoptosis in cells in a dose- and time-dependent manner. The biological effects were inhibited by catalase. Conclusion: Bl-LAAO, a major component of B. leucurus venom, is a cytotoxin acting primarily via the generation of high amounts of H 2O2 which kill the cells. General significance: These results allow us to consider the use of LAAOs as anticancer agents, as tools in biochemical studies to investigate cellular processes, and to obtain a better understanding of the envenomation mechanism. © 2011 Elsevier B.V. All rights reserved.

de Souza R.A.,Federal University of Sao Joao del Rei | Di Lorenzo Oliveira C.,Federal University of Sao Joao del Rei | Lima-Costai M.F.,Research Center Rene Rachou
Revista Brasileira de Epidemiologia | Year: 2014

The objective of this study was to examine the association between individual satisfaction with social and physical surroundings and the habit of smoking cigarettes. Data from the Health Survey of Adults from the metropolitan area of Belo Horizonte, Minas Gerais, Brazil, were used. Based on a probability sample, participants (n = 12,299) were selected among residents aged 20 years old or more. The response variable was the smoking habit and the explanatory variable of interest was the neighborhood perception. Potential confounding variables included demographic characteristics, health behaviors and other indicators of socioeconomic position. The prevalence of current smokers, former smokers and never smokers were 20.8, 14.1 and 65.1%, respectively; 74.4 and 25.5% of the participants were categorized as being more satisfied and less satisfied with the neighborhood, respectively. Compared to those who never smoked, former smokers (adjusted odds ratio = 1.40, 95% confidence interval 1.20 – 1.62) and current smokers (adjusted odds ratio = 1.17, 95% confidence interval 1.03 – 1.34) were less satisfied with the neighborhood compared to those who never smoked. The results of this study indicate there is an independent association between the smoking habit and a less satisfying neighborhood perception in the metropolitan region of Belo Horizonte, which does not depend on individual characteristics, traditionally reported as being associated with smoking. © 2014, Assocaicao Brasileira de Pos, Gradacao em Saude Coletiva. All rights reserved.

Teixeira K.N.,Federal University of Minas Gerais | Souza K.N.,Federal University of Minas Gerais | Vidigal T.H.D.A.,Federal University of Minas Gerais | Brito C.A.,Research Center Rene Rachou | And 3 more authors.
Genes | Year: 2010

Introns are common among all eukaryotes, while only a limited number of introns are found in prokaryotes. Globin and globin-like proteins are widely distributed in nature, being found even in prokaryotes and a wide range of patterns of intron-exon have been reported in several eukaryotic globin genes. Globin genes in invertebrates show considerable variation in the positions of introns; globins can be found without introns, with only one intron or with three introns in different positions. In this work we analyzed the introns in the myoglobin gene from Biomphalaria glabrata, B. straminea and B. tenagophila. In the Biomphalaria genus, the myoglobin gene has three introns; these were amplified by PCR and analyzed by PCR-RFLP. Results showed that the size (number or nucleotides) and the nucleotide sequence of the coding gene of the myoglobin are variable in the three species. We observed the presence of size polymorphisms in intron 2 and 3; this characterizes a homozygous/heterozygous profile and it indicates the existence of two alleles which are different in size in each species of Biomphalaria. This polymorphism could be explored for specific identification of Biomphalaria individuals. © 2010 by the authors; licensee MDPI, Basel, Switzerland.

Sarvel A.K.,Research Center Rene Rachou | Oliveira A.A.,Research Center Rene Rachou | Silva A.R.,Federal University of Ouro Preto | Lima A.C.L.,Federal University of Minas Gerais | Katz N.,Research Center Rene Rachou
PLoS Neglected Tropical Diseases | Year: 2011

Background: Various studies showed that chemotherapy can control schistosomiasis morbidity, but association of measures (water supply, sewage disposal and increase of socioeconomic conditions) is necessary for transmission control. Methodology/Principal Findings: A survey dealing with socioeconomic conditions, snail survey, contact with natural waters, and clinical and stool examinations was undertaken at an endemic area in the State of Minas Gerais, Brazil. The methodology used was the same for both evaluations (1981 and 2005). Four hundred and seventy-five out of 1,474 individuals studied in 1981 could be contacted. From these, 358 were submitted to stool examination, and 231 of them were clinically examined. Patients eliminating S. mansoni eggs in their stools were treated. The results showed that the prevalence rate in Comercinho, a municipality of the State of Minas Gerais, Brazil, was substantially reduced to 70.4% and 1.7% in 1981 and 2005, respectively, as well as the frequency of the hepatosplenic form (7% to 1.3%) after five treatments effectuated between 1981 and 1992. No other new case of this form was detected from 1981 onwards. Another important aspect to be considered was the improvement of people's living standard that occurred in the region after more than two decades' efforts (better housing, professional skill and adequate basic sanitation). Conclusion/Significance: The control of morbidity and very significant decrease of schistosomiasis transmission in an area until then considered as hyperendemic was possible by means of association of successive specific treatments of the local population, together with the construction of privies, water supply in the houses and improvement of socioeconomic conditions. © 2011 Sarvel et al.

Barcelos Morais Da Silveira A.,Federal University of Uberlandia | Barcelos Morais Da Silveira A.,Research Center Rene Rachou | De Oliveira E.C.,Federal University of Goais | Neto S.G.,Federal University of Goais | And 5 more authors.
Human Pathology | Year: 2011

Chagas disease is one of the most serious parasitic diseases of Latin America, with a social and economic impact far outweighing the combined effects of other parasitic diseases such as malaria, leishmaniasis, and schistosomiasis. In the chronic phase of this disease, the destruction of enteric nervous system components leads to megacolon development. Besides neurons, the enteric nervous system is constituted by enteric glial cells, representing an extensive but relatively poorly described population within the gastrointestinal tract. Several lines of evidence suggest that enteric glial cells represent an equivalent of central nervous system astrocytes. Previous data suggest that enteric glia and neurons are active in the enteric nervous system during intestinal inflammatory and immune responses. To evaluate whether these cells act as antigen-presenting cells, we investigated the expression of molecules responsible for activation of T cells, such as HLA-DR complex class II and costimulatory molecules (CD80 and CD86), by neurons and enteric glial cells. Our results indicate that only enteric glial cells of chagasic patients with megacolon express HLA-DR complex class II and costimulatory molecules, and hence they present the attributes necessary to act as antigen-presenting cells. © 2011 Elsevier Inc. All rights reserved.

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