97 research outputs found

    Protective effect of EGb761 against Aβ1-42 -induced SHSY5Y cells injury and blood-brain barrier disruption via regulating Akt/Nrf2 signaling pathway

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    Purpose: Alzheimer’s disease (AD) is a common disease in the world caused by deposition in the brain parenchyma, accumulation of beta amyloid which leads to the blood brain barrier (BBB) disruption. Regardless of enough progress in the treatment of AD, the principal mechanism of BBB injury is yet not clear.Methods: In this study we examined the impact of EGb761on Aβ 1-42-induced SH-SY5Y cells in vitro  model of AD. Cell viability was assessed by using MTT assay, flow cytometry was used to check the rate of cell apoptosis, ROS generation and BBB leakage was assessed by measuring the level of fluorescence in Aβ-induced SH-SY5Y cells using a reactive oxygen species kit assay and BBB permeability assay, and mRNA levels of Bax, Bcl-2, caspase-3 was measured by using RT-qPCR.  Furthermore, western blot analysis was used to measure the protein expressions of Akt, Nrf2 and HO-1 in Aβ 1-42-induced SH-SY5Y cells.Results: The effect of EGb761 was investigated on the cell apoptosis induced by Aβ 1-42 andgeneration of ROS and we found that EGb761 plays a protective role against cell injury induced by Aβ 1-42. Cell apoptosis and ROS generation in SH-SY5Y cells decreased significantly with the treatment of EGb761. Furthermore, BBB permeability reduced considerably when the cells treated with EGb761 and the expression levels of Caspase-3 and Bax decreased while that of Bcl-2 were markedly increased in the Aβ 1-42-induced SH-SY5Y cells. Also, an increased in expression levels of p-Akt, Nrf2 (nucleus) and HO-1 was observed with the treatment of EGb761 in Aβ 1-42-induced SH-SY5Y cells.Conclusion: It can be concluded from these results that EGb761 could play a protective role byinhibiting apoptosis and protect Aβ 1-42-induced cell injury in vitro model of AD via activating Akt/Nrf2signaling pathway. Our study suggested that EGb761 might be a therapeutic agent for the preventionand treatment of AD

    Perfusion defect size predicts engraftment but not early retention of intra-myocardially injected cardiosphere-derived cells after acute myocardial infarction

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    Therapeutic cell retention and engraftment are critical for myocardial regeneration. Underlying mechanisms, including the role of tissue perfusion, are not well understood. In Wistar Kyoto rats, syngeneic cardiosphere-derived cells (CDCs) were injected intramyocardially, after experimental myocardial infarction. CDCs were labeled with [18F]-FDG (n = 7), for quantification of 1-h retention, or with sodium-iodide-symporter gene (NIS; n = 8), for detection of 24-h engraftment by reporter imaging. Perfusion was imaged simultaneously. Infarct size was 37 ± 9 and 38 ± 9% of LV in FDG and NIS groups. Cell signal was located in the infarct border zone in all animals. No significant relationship was observed between infarct size and 1-h CDC retention (r = −0.65; P = 0.11). However, infarct size correlated significantly with 24-h engraftment (r = 0.75; P = 0.03). Residual perfusion at the injection site was not related to cell retention/engraftment. Larger infarcts are associated with improved CDC engraftment. This observation encourages further investigation of microenvironmental conditions after ischemic damage and their role in therapeutic cell survival

    Effects of crystallization and dopant concentration on the emission behavior of TiO2:Eu nanophosphors

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    Uniform, spherical-shaped TiO2:Eu nanoparticles with different doping concentrations have been synthesized through controlled hydrolysis of titanium tetrabutoxide under appropriate pH and temperature in the presence of EuCl3·6H2O. Through air annealing at 500°C for 2 h, the amorphous, as-grown nanoparticles could be converted to a pure anatase phase. The morphology, structural, and optical properties of the annealed nanostructures were studied using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy [EDS], and UV-Visible diffuse reflectance spectroscopy techniques. Optoelectronic behaviors of the nanostructures were studied using micro-Raman and photoluminescence [PL] spectroscopies at room temperature. EDS results confirmed a systematic increase of Eu content in the as-prepared samples with the increase of nominal europium content in the reaction solution. With the increasing dopant concentration, crystallinity and crystallite size of the titania particles decreased gradually. Incorporation of europium in the titania particles induced a structural deformation and a blueshift of their absorption edge. While the room-temperature PL emission of the as-grown samples is dominated by the 5D0 - 7Fj transition of Eu+3 ions, the emission intensity reduced drastically after thermal annealing due to outwards segregation of dopant ions

    Identification of a Marine Bacillus Strain C5 and Parathion-Methyl Degradation Characteristics of the Extracellular Esterase B1

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    A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value

    Financing, Reputation and Information Disclosure Quality in the Chinese Market

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    In this article, we propose a theoretical model based on the reputation theory and hypothesize a positive relation between the information disclosure quality and the company\u27s refinancing decision. We collected data from the listed companies, which refinances in Shenzhen main board and SME board during 2006—2012, as a panel sample, and tested the hypothesis empirically. The results indicate that there exists a significant positive correction short-term relation between refinancing decision and the information disclosure quality, but in the long term the relationship between the information disclosure quality and refinancing decision is not significant

    Tectonic evolution of the Dabashan orocline, central China: Insights from the superposed folds in the eastern Dabashan foreland

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    The Dabashan orocline is situated in the northwestern margin of the central Yangtze block, central China. Previous studies have defined the orthogonal superposed folds growing in its central-western segment thereby confirming its two-stage tectonic evolution history. Geological mapping has revealed that more types of superposed folds have developed in the eastern segment of the orocline, which probably provides more clues for probing the structure and tectonic history of the Dabashan orocline. In this paper, based on geological mapping, structural measurements and analyses of deformation, we have identified three groups of folds with different trends (e.g. NW-, NE- and nearly E-trending folds) and three types of structural patterns of superposed folds in the eastern Dabashan foreland (e.g. syn-axial, oblique, and conjunctional superposed folds). In combination with geochronological data, we propose that the syn-axial superposed folds are due to two stages of ∼N–S shortening in the west and north of the Shennongjia massif, and that oblique superposed folds have been resulted from the superposition of the NW- and NE-trending folds onto the early ∼E–W folds in the east of the Shennongjia massif in the late Jurassic to early Cretaceous. The conjunctional folds are composed of the NW- and NE-trending folds, corresponding to the regional-scale dual-orocline in the eastern Sichuan as a result of the southwestward expansion of the Dabashan foreland during late Jurassic to early Cretaceous, coeval with the northwestward propagation of the Xuefengshan foreland. Integration of the structure and geochronology of the belt shows that the Dabashan orocline is a combined deformation belt primarily experiencing a two-stage tectonic evolution history in Mesozoic, initiation of the Dabashan orocline as a foreland basin along the front of the Qinling orogen in late Triassic to early Jurassic due to collisional orogeny, and the final formation of the Dabashan orocline owing to the southwestward propagation of the Qinling orogen during late Jurassic to early Cretaceous intra-continental orogeny. Our studies provide some evidences for understanding the structure and deformation of the Dabashan orocline

    Point process models, the dimensions of biodiversity and the importance of small-scale biotic interactions

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    Aims Recent mechanistic explanations for community assembly focus on the debates surrounding niche-based deterministic and dispersal-based stochastic models. This body of work has emphasized the importance of both habitat filtering and dispersal limitation, and many of these works have utilized the assumption of species spatial independence to simplify the complexity of the spatial modeling in natural communities when given dispersal limitation and/or habitat filtering. One potential drawback of this simplification is that it does not consider species interactions and how they may influence the spatial distribution of species, phylogenetic and functional diversity. Here, we assess the validity of the assumption of species spatial independence using data from a subtropical forest plot in southeastern China. Methods We use the four most commonly employed spatial statistical models-the homogeneous Poisson process representing pure random effect, the heterogeneous Poisson process for the effect of habitat heterogeneity, the homogenous Thomas process for sole dispersal limitation and the heterogeneous Thomas process for joint effect of habitat heterogeneity and dispersal limitation-to investigate the contribution of different mechanisms in shaping the species, phylogenetic and functional structures of communities. Important Findings Our evidence from species, phylogenetic and functional diversity demonstrates that the habitat filtering and/or dispersal-based models perform well and the assumption of species spatial independence is relatively valid at larger scales (50 x 50 m). Conversely, at local scales (10 x 10 and 20 x 20 m), the models often fail to predict the species, phylogenetic and functional diversity, suggesting that the assumption of species spatial independence is invalid and that biotic interactions are increasingly important at these spatial scales
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