74 research outputs found

    Physiological aspects of angiotensin II-dependent hypertension: an overview

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    Hypertension is one of the main causes of death in developed and developing countries, inducing great impact in human health. Oxidative stress has been implicated as a key mechanism in Angiotensin II-dependent hypertension, since it modulates the baroreflex function in many pathophysiological processes. This study aimed to conduct a literature review addressing the recent mechanisms that promote changes in Angiotensin II-dependent hypertension. Here we highlighted two Angiotensin II-dependent hypertension models: two kidney-one-clip (2K1C) and deoxycorticosterone (DOCA-salt) hypertension. Bases on latest studies presented in important data base, it is possible to suggest that Angiotensin II is one of the main agents in hypertension development and the increase of this peptide is derived by multiple causes, which, in particular, acts as an inductor in oxidative stress production, in turn, it induces changes in a metalloprotease 17 (ADAM-17) and disruption of ACE2 compensatory activity. Thus, new tools that induce a reduction of oxidative stress promote beneficial effects, providing novel therapeutic targets to prevent and treat the Angiotensin II-dependent hypertension

    Contribuição socioeconômica da sub-bacia hidrográfica do rio Caiapó para o município de Marianópolis do Tocantins

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    A bacia hidrográfica Tocantins-Araguaia tem uma área de 960 mil km² e possui um desmembramento que deu origem à sub-bacia do Rio Caiapó, que apresenta uma área de 5.382,1 km2. A sub-bacia do Rio Caiapó está inserida em uma região que tem uma demanda de uso de seus recursos, com predominância nas atividades de abastecimento populacional, dessedentação animal e incumbência agropecuária. O estudo tem como finalidade uma explanação breve do comportamento hidrológico da sub-bacia hidrográfica do Rio Caiapó e a apresentação das diferentes contribuições que manifesta na cidade de Marianópolis-TO. Os resultados nos possibilitaram entender a dinâmica social da sub- bacia em relação aos seus elementos físicos e bióticos, compreendendo sua extensão, geologia e topografia, e também sua relação com o meio social, justificada pelos principais usos desta

    Respiratory allergy to Blomia tropicalis: Immune response in four syngeneic mouse strains and assessment of a low allergen-dose, short-term experimental model

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    <p>Abstract</p> <p>Background</p> <p>The dust mite <it>Blomia tropicalis </it>is an important source of aeroallergens in tropical areas. Although a mouse model for <it>B. tropicalis </it>extract (<it>Bt</it>E)-induced asthma has been described, no study comparing different mouse strains in this asthma model has been reported. The relevance and reproducibility of experimental animal models of allergy depends on the genetic background of the animal, the molecular composition of the allergen and the experimental protocol.</p> <p>Objectives</p> <p>This work had two objectives. The first was to study the anti-<it>B. tropicalis </it>allergic responses in different mouse strains using a short-term model of respiratory allergy to <it>Bt</it>E. This study included the comparison of the allergic responses elicited by <it>Bt</it>E with those elicited by ovalbumin in mice of the strain that responded better to <it>Bt</it>E sensitization. The second objective was to investigate whether the best responder mouse strain could be used in an experimental model of allergy employing relatively low <it>Bt</it>E doses.</p> <p>Methods</p> <p>Groups of mice of four different syngeneic strains were sensitized subcutaneously with 100 μg of <it>Bt</it>E on days 0 and 7 and challenged four times intranasally, at days 8, 10, 12, and 14, with 10 μg of <it>Bt</it>E. A/J mice, that were the best responders to <it>Bt</it>E sensitization, were used to compare the <it>B. tropicalis</it>-specific asthma experimental model with the conventional experimental model of ovalbumin (OVA)-specific asthma. A/J mice were also sensitized with a lower dose of <it>Bt</it>E.</p> <p>Results</p> <p>Mice of all strains had lung inflammatory-cell infiltration and increased levels of anti-<it>Bt</it>E IgE antibodies, but these responses were significantly more intense in A/J mice than in CBA/J, BALB/c or C57BL/6J mice. Immunization of A/J mice with <it>Bt</it>E induced a more intense airway eosinophil influx, higher levels of total IgE, similar airway hyperreactivity to methacholine but less intense mucous production, and lower levels of specific IgE, IgG1 and IgG2 antibodies than sensitization with OVA. Finally, immunization with a relatively low <it>Bt</it>E dose (10 μg per subcutaneous injection per mouse) was able to sensitize A/J mice, which were the best responders to high-dose <it>Bt</it>E immunization, for the development of allergy-associated immune and lung inflammatory responses.</p> <p>Conclusions</p> <p>The described short-term model of <it>Bt</it>E-induced allergic lung disease is reproducible in different syngeneic mouse strains, and mice of the A/J strain was the most responsive to it. In addition, it was shown that OVA and <it>Bt</it>E induce quantitatively different immune responses in A/J mice and that the experimental model can be set up with low amounts of <it>Bt</it>E.</p

    Evaluation of the effects of Quercetin and Kaempherol on the surface of MT-2 cells visualized by atomic force microscopy

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    AbstractThis study investigated the anti-viral effects of the polyphenolic compounds Quercetin and Kaempherol on the release of HTLV-1 from the surface of MT-2 cells. Atomic force microscopy (AFM) was used to scan the surface of the MT-2 cells. MT-2 cells were fixed with 100% methanol on round glass lamina or cleaved mica and dried under UV light and laminar flow. The images were captured on a Multimode equipment monitored by a NanoScope IIId controller from Veeco Instruments Inc operated in tapping mode and equipped with phase-imaging hardware. The images demonstrated viral budding structures 131±57nm in size, indicating profuse viral budding. Interestingly, cell-free viruses and budding structures visualized on the surface of cells were less common when MT-2 was incubated with Quercetin, and no particles were seen on the surface of cells incubated with Kaempherol. In summary, these data indicate that HTLV-1 is budding constantly from the MT-2 cell surface and that polyphenolic compounds were able to reduce this viral release. Biological samples were analyzed with crude cell preparations just after cultivation in the presence of Quercetin and Kaempherol, showing that the AFM technique is a rapid and powerful tool for analysis of antiviral activity of new biological compounds

    Maternal Toxoplasma gondii infection affects proliferation, differentiation and cell cycle regulation of retinal neural progenitor cells in mouse embryo

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    BackgroundToxoplasmosis affects one third of the world population and has the protozoan Toxoplasma gondii as etiological agent. Congenital toxoplasmosis (CT) can cause severe damage to the fetus, including miscarriages, intracranial calcification, hydrocephalus and retinochoroiditis. Severity of CT depends on the gestational period in which infection occurs, and alterations at the cellular level during retinal development have been reported. In this study, we proposed a mouse CT model to investigate the impact of infection on retinal development.MethodsPregnant females of pigmented C57BL/6 strain mice were infected intragastrically with two T. gondii cysts (ME49 strain) at embryonic day 10 (E10), and the offspring were analyzed at E18.ResultsInfected embryos had significantly smaller body sizes and weights than the PBS-treated controls, indicating that embryonic development was affected. In the retina, a significant increase in the number of Ki-67-positive cells (marker of proliferating cells) was found in the apical region of the NBL of infected mice compared to the control. Supporting this, cell cycle proteins Cyclin D3, Cdk6 and pChK2 were significantly altered in infected retinas. Interestingly, the immunohistochemical analysis showed a significant increase in the population of β-III-tubulin-positive cells, one of the earliest markers of neuronal differentiation.ConclusionsOur data suggests that CT affects cell cycle progression in retinal progenitor cells, possibly inducing the arrest of these cells at G2/M phase. Such alterations could influence the differentiation, anticipating/increasing neuronal maturation, and therefore leading to abnormal retinal formation. Our model mimics important events observed in ocular CT

    Productive and economic performance of feedlot young Nellore bulls fed whole oilseeds

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    ABSTRACT The effects of diets containing oilseeds were measured to evaluate the productive and economic parameters in the finishing of young, feedlot Nellore bulls. Twenty-four young Nellore bulls were used, with an initial body weight (BW) of 311.46±0.37 kg and 24 months of age, distributed into individual stalls ( 4 × 20 m) in a completely randomized design, totaling four treatments with six repetitions per treatment. Four diets (control, based on corn and soybean meal, and three diets containing cottonseed, soybean, and sunflower) were evaluated. Feed and orts were measured daily to calculate intake and costs. The dry matter intake of the control group was higher than soybean (10.64 kg/day), cotton (9.88 kg/day), and sunflower (9.30 kg/day) treatments, respectively. The cottonseed treatment showed the highest average neutral detergent fiber intake. There was a dietary effect of diets on average daily gain, total weight gain, and final weight. The soybean treatment showed the highest performance, total gain (232.55 kg), and final weight (544.38 kg). Oilseed intake can modify the fatty acids profile in the meat, decreasing its saturated fatty acid content. Whole soybean seed favors performance, improves feed efficiency, fatty acid profile, and fat distribution in the carcass, and can reduce production costs

    Violência de Estado no Brasil: uma análise dos Crimes de Maio de 2006 na perspectiva da antropologia forense e da justiça de transição - relatório final

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    O objetivo deste relatório é apresentar os resultados do projeto “Violência de Estado no Brasil: um estudo dos Crimes de Maio de 2006 na perspectiva da antropologia forense e da justiça de transição”. A pesquisa analisou sessenta casos de pessoas assassinadas na região da Baixada Santista entre os dias 12 e 20 de maio de 2006, a fim de entender a dinâmica da violência, o perfil das vítimas e analisar indícios de execução sumária. Dessa forma, esperamos que os resultados possam contribuir com o esclarecimento dos crimes e com a demanda de justiça dos familiares das vítimas, e também colaborar com o debate sobre a violência de Estado no Brasil e com a construção de uma democracia real no país, conforme estabelecido pelos pilares da justiça de transição
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