1000 resultados para processos de pesquisa


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Foi pesquisada a presença de riquétsias em 3.545 carrapatos Amblyomma cajennense e 2.666 Amblyomma dubitatum. Através do teste de hemolinfa, reação em cadeia pela polimerase e isolamento de rickettsia em cultivo celular, todos os Amblyomma cajennense foram negativos, sendo que 634 (23,8%) Amblyomma dubitatum mostraram-se infectados com Rickettsia bellii.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The connexin 32 (Cx32) is a protein that forms the channels that promote the gap junction intercellular communication (GJIC) in the liver, allowing the diffusion of small molecules through cytosol from cell-to-cell. Hepatic fibrosis is characterized by a disruption of normal tissue architeture by cellular lesions, and may alter the GJIC. This work aimed to study the expression and distribution of Cx32 in liver fibrosis induced by the oral administration of dimethylnitrosamine in female Wistar rats. The necropsy of the rats was carried out after five weeks of drug administration. They presented a hepatic fibrosis state. Sections from livers with fibrosis and from control livers were submitted to immunohistochemical, Real Time-PCR and Western-Blot analysis to Cx32. In fibrotic livers the Cxs were diffusely scattered in the cytoplasm, contrasting with the control livers, where the Cx32 formed junction plaques at the cell membrane. Also it was found a decrease in the gene expression of Cx32 without reduction in the protein quantity when compared with controls. These results suggest that there the mechanism of intercellular communication between hepatocytes was reduced by the fibrotic process, which may predispose to the occurrence of a neoplastic process, taken in account that connexins are considered tumor suppressing genes.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A França passou por conflitos urbanos em seus bairros populares. Incidentes com a polícia marcados pela morte de um morador, geralmente jovem ou adolescente, são seguidos por manifestações violentas: quebra-quebras, incêndios de carros e/ou estabelecimentos públicos e privados, enfrentamentos com a polícia. Nos conflitos da "banlieue" francesa podem ser percebidos elementos comuns a eventos ingleses e/ou americanos de outras décadas.OBJETIVO: consiste em identificar a percepção e as representações de moradores sobre suas condições de vida e saúde na França.MÉTODO: pesquisa qualitativa realizada em Les Aubiers, bairro popular de Bordeaux, nos anos de 2002 e 2005. A população de moradores desse bairro e é composta principalmente por imigrantes ou fanceses de origem estrangeira, provenientes de diferentes locais: África do Norte, África Sub-Sahariana, Turquia, Portugal , Ilha de Reunião. Os indicadores sociais e econômicos apresentam níveis significativamente mais baixos do que os de outros bairros de Bordeaux, acompanhando as tendências encontradas nas outras "banlieues". Entre esses indicadores, a taxa de desemprego, principalmente entre jovens, é alarmante (40 por cento).RESULTADOS E DISCUSSÃO: as políticas sociais deveriam ser mais voltadas para os indivíduos do que para o território, pois este só poderá ser transformado pelos primeiros e não o contrário. Um bairro e uma população estigmatizados, estão contemplados por uma ampla política social. Ainda que passível de crítica, não se pode ignorar a existência de esforços sistematicos de integração, nem a existência de políticas sociais. Se elas são inadequadas, trata-se de ampliar o espaço de discusão para sua reforma. Trata-se de saber qual a disposição das sociedades contemporâneas, como um todo, para lutar contra as inequidades e segregações

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally. Results: We developed a novel and non-toxic formulation of cationic liposomes, in which the DNA-hsp65 vaccine was entrapped (ENTR-hsp65) or complexed (COMP-hsp65), and used to immunize mice by intramuscular or intranasal routes. Although both liposome formulations induced a typical Th1 pattern of immune response, the intramuscular route of delivery did not reduce the number of bacilli. However, a single intranasal immunization with COMP-hsp65, carrying as few as 25 mu g of plasmid DNA, leads to a remarkable reduction of the amount of bacilli in lungs. These effects were accompanied by increasing levels of IFN-gamma and lung parenchyma preservation, results similar to those found in mice vaccinated intramuscularly four times with naked DNA-hsp65 (total of 400 mu g). Conclusion: Our objective was to overcome the significant obstacles currently facing DNA vaccine development. Our results in the mouse TB model showed that a single intranasal dose of COMP-hsp65 elicited a cellular immune response that was as strong as that induced by four intramuscular doses of naked-DNA. This formulation allowed a 16-fold reduction in the amount of DNA administered. Moreover, we demonstrated that this vaccine is safe, biocompatible, stable, and easily manufactured at a low cost. We believe that this strategy can be applied to human vaccines to TB in a single dose or in prime-boost protocols, leading to a tremendous impact on the control of this infectious disease.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper analyzes the temporal evolution of scientific accounting research in Brazil and the relationship between as not-motive and positive approaches. In order to do so, this study was based on documental descriptive research of papers submitted at the Annual Meeting of the National Association of the Post-Graduation Programs in Management (ENANPADs), from 1996 to 2005. Bibliometrics (Lotka's Law) was used to assess the productivity of the authors of the papers. The results are consistent with the results obtained by Fulbier and Sellhorn (2006) in Europe and reveal that authors predominantly adopt a positive approach,few researchers use the two approaches and confirm that Brazilian researchers have a lower productivity in comparison to those who publish in English-language periodicals.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The analysis of interviews with open-ended questions is a common practice amongst researchers in the field of Management. The difficulty therein is to convert the linguistic data into categories or quantitative values for subsequent statistical treatment. Proposals made to this end generally entail counting lexical occurrences which, since they are founded on previously established meanings, fail to include semantic associations made by interviews. This article aims to present an analysis tool comprising a set of techniques apt to generate linguistic units that can be statistically described, compared, modeled and inferred: the Quantitative Propositional Analysis (QPA), Its main difference from other such methods lies in the choice of a proposition - and not the lexical unit - as analysis unit. We present the application of this method through a study about the international expansion of retail firms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Endoplasmic reticulum (ER) stress has pathophysiological relevance in vascular diseases and merges with proteasome function. Proteasome inhibition induces cell stress and may have therapeutic implications. However, whether proteasome inhibition potentiates ER stress-induced apoptosis and the possible mechanisms involved in this process are unclear. Methodology/Principal Findings: Here we show that proteasome inhibition with MG132, per se at non-lethal levels, sensitized vascular smooth muscle cells to caspase-3 activation and cell death during ER stress induced by tunicamycin (Tn). This effect was accompanied by suppression of both proadaptive (KDEL chaperones) and proapoptotic (CHOP/GADD153) unfolded protein response markers, although, intriguingly, the splicing of XBP1 was markedly enhanced and sustained. In parallel, proteasome inhibition completely prevented ER stress-induced increase in NADPH oxidase activity, as well as increases in Nox4 isoform and protein disulfide isomerase mRNA expression. Increased Akt phosphorylation due to proteasome inhibition partially offset the proapoptotic effect of Tn or MG132. Although proteasome inhibition enhanced oxidative stress, reactive oxygen species scavenging had no net effect on sensitization to Tn or MG132-induced cell death. Conclusion/Relevance: These data indicate unfolded protein response-independent pathways whereby proteasome inhibition sensitizes vascular smooth muscle to ER stress-mediated cell death. This may be relevant to understand the therapeutic potential of such compounds in vascular disease associated with increased neointimal hyperplasia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The decomposition of peroxynitrite to nitrite and dioxygen at neutral pH follows complex kinetics, compared to its isomerization to nitrate at low pH. Decomposition may involve radicals or proceed by way of the classical peracid decomposition mechanism. Peroxynitrite (ONOOH/ONOO(-)) decomposition has been proposed to involve formation of peroxynitrate (O(2)NOOH/O(2)NOO(-)) at neutral pH (D. Gupta, B. Harish, R. Kissner and W. H. Koppenol, Dalton Trans., 2009, DOI: 10.1039/b905535e, see accompanying paper in this issue). Peroxynitrate is unstable and decomposes to nitrite and dioxygen. This study aimed to investigate whether O(2)NOO(-) formed upon ONOOH/ONOO(-) decomposition generates singlet molecular oxygen [O(2) ((1)Delta(g))]. As unequivocally revealed by the measurement of monomol light emission in the near infrared region at 1270 nm and by chemical trapping experiments, the decomposition of ONOO(-) or O(2)NOOH at neutral to alkaline pH generates O(2) ((1)Delta(g)) at a yield of ca. 1% and 2-10%, respectively. Characteristic light emission, corresponding to O(2) ((1)Delta(g)) monomolecular decay was observed for ONOO(-) and for O(2)NOOH prepared by reaction of H(2)O(2) with NO(2)BF(4) and of H(2)O(2) with NO(2)(-) in HClO(4). The generation of O(2) ((1)Delta(g)) from ONOO(-) increased in a concentration-dependent manner in the range of 0.1-2.5 mM and was dependent on pH, giving a sigmoid pro. le with an apparent pK(a) around pD 8.1 (pH 7.7). Taken together, our results clearly identify the generation of O(2) ((1)Delta(g)) from peroxynitrate [O(2)NOO(-) -> NO(2)(-) + O(2) ((1)Delta(g))] generated from peroxynitrite and also from the reactions of H(2)O(2) with either NO(2)BF(4) or NO(2)(-) in acidic media.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Enhanced mitochondrial biogenesis promoted by eNOS activation is believed to play a central role in the beneficial effects of calorie restriction (CR). Since treatment of mice with dinitrophenol (DNP) promotes health and lifespan benefits similar to those observed in CR, we hypothesized that it could also impact biogenesis. We found that DNP and CR increase citrate synthase activity, PGC-1 alpha, cytochrome c oxidase and mitofusin-2 expression, as well as fasting plasma levels of NO(center dot) products. In addition, eNOS and Akt phosphorylation in skeletal muscle and visceral adipose tissue was activated in fasting CR and DNP animals. Overall, our results indicate that systemic mild uncoupling activates eNOS and Akt-dependent pathways leading to mitochondrial biogenesis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Singlet molecular oxygen O(2)((1)Delta(g)) is a potent oxidant that can react with different biomolecules, including DNA, lipids and proteins. Many polycyclic aromatic hydrocarbons have been studied as O(2)((1)Delta(g)) chemical traps. Nevertheless, a suitable modification in the polycyclic aromatic ring must be made to increase the yield of O(2)((1)Delta(g)) chemical trapping. With this goal, an anthracene derivative, diethyl-3,3 '-(9,10-anthracenediyl)bisacrylate (DADB), was obtained from the reaction of 9,10-dibromoanthracene and ethyl acrylate through the Heck coupling reaction. The coupling of ethyl acrylate with the anthracene ring produced a new lipophilic, esterified, fluorescent probe reactive toward O(2)((1)Delta(g)). This compound reacts with O(2)((1)Delta(g)) at a rate of k(r) = 1.69 x 10(6) M(-1) s(-1) forming a stable endoperoxide (DADBO(2)), which was characterized by UV-Vis, fluorescence, HPLC/MS and (1)H and (13)C NMR techniques. The photophysical, photochemical and thermostability features of DADB were also evaluated. Furthermore, this compound has the potential for great application in biological systems because it is easily synthetized in large amount and generates specific endoperoxide (DADBO(2)), which can be easily detected by HPLC tandem mass spectrometry (HPLC/MS/MS).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ubiquitin-proteasome system governs the half-life of most cellular proteins. Calorie restriction (CR) extends the maximum life span of a variety of species and prevents oxidized protein accumulation. We studied the effects of CR on the ubiquitin-proteasome system and protein turnover in aging Saccharomyces cerevisiae. CR increased chronological life span as well as proteasome activity compared to control cells. The levels of protein carbonyls, a marker of protein oxidation, and those of polyubiquitinated proteins were modulated by CR. Controls, but not CR cells, exhibited a significant increase in oxidized proteins. In keeping with decreased proteasome activity, polyubiquitinated proteins were increased in young control cells compared to time-matched CR cells, but were profoundly decreased in aged control cells despite decreased proteasomal activity. This finding is related to a decreased polyubiquitination ability due to the impairment of the ubiquitin-activating enzyme in aged control cells, probably related to a more oxidative microenvironment. CR preserves the ubiquitin-proteasome system activity. Overall, we found that aging and CR modulate many aspects of protein modification and turnover. (C) 2011 Elsevier Inc. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Durante os anos de 2005 e 2006, a Secretaria Nacional de Renda de Cidadania (Senarc/MDS), por interm??dio do Departamento do Cadastro ??nico, conduziu uma s??rie de a????es com o objetivo de aprimorar os procedimentos envolvidos na gest??o do Cadastro ??nico (Cad??nico), contribuindo para a melhoria da fidedignidade e da qualidade dos dados cadastrais e, por conseguinte, dos mecanismos de sele????o e acompanhamento dos programas que utilizam o Cad??nico como base de identifica????o e sele????o de seu p??blico-alvo, em especial, do Programa Bolsa Fam??lia. Este trabalho apresenta as a????es conduzidas para a melhoria e o fortalecimento da gest??o do Cadastro ??nico entre janeiro de 2005 e outubro de 2006, bem como o impacto dessas a????es para a gest??o dos programas usu??rios do Cad??nico. Al??m das a????es diretas relativas ?? gest??o do Cad??nico, s??o tamb??m descritas outras a????es da Senarc que, embora n??o coordenadas pelo Departamento de Cadastro ??nico, influenciaram diretamente as a????es realizadas por esse Departamento

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O Sisbio ?? um sistema informatizado de autoriza????o e de informa????o que objetiva melhorar o atendimento a pesquisadores cujos estudos envolvem coleta de material biol??gico ou s??o desenvolvidos em unidades de conserva????o da natureza ou ainda, em cavernas. Por meio do preenchimento e envio de formul??rios pela internet, pesquisadores solicitam ao Instituto Chico Mendes de Conserva????o da Biodiversidade (ICMBio) autoriza????es para as atividades supracitadas. Pelo sistema, os pesquisadores tamb??m apresentam seus relat??rios de atividades, cujas informa????es compor??o um banco de dados georreferenciado. Anteriormente, essas autoriza????es eram emitidas em papel a partir da an??lise do projeto de pesquisa impresso enviado por correio. Os relat??rios das atividades autorizadas eram arquivados em processos, tornando as informa????es neles contidas pouco dispon??veis para a consulta. O Sisbio mudou esse quadro, promovendo celeridade e transpar??ncia na an??lise, bem como a otimiza????o da gest??o e uso da informa????o