56 research outputs found
Acute exercise induce endothelial nitric oxide synthase phosphorylation via Akt and AMP-activated protein kinase in aorta of rats: Role of reactive oxygen species
AbstractBackgroundAcute exercise increases reactive oxygen species (ROS) levels, including hydrogen peroxide (H2O2). H2O2 promotes endothelial nitric oxide synthase (eNOS) activation and phosphorylation in endothelial cells. With this in mind, the present study was designed to evaluate ex vivo eNOS phosphorylation in rat aortas incubated with H2O2 and to test this hypothesis in vivo in the aortas of rats submitted to acute exercise.MethodsFor ex vivo studies, six groups of aortic tissue were formed: control, H2O2, N-acetylcysteine (NAC), LY294002, compound C, and LY294002 plus compound C. While incubation with H2O2 increased Akt, AMPK and eNOS phosphorylation, pre-incubation with NAC strongly reduced the phosphorylation of these enzymes. For in vivo studies, male Wistar rats were divided into four groups: control, cont+NAC, exercise, and exer+NAC. After a 3h swimming session, animals were decapitated and aortas were excised for biochemical and immunoblotting analysis.ResultsAcute exercise increased superoxide levels and dichlorofluorescein (DCF) concentrations, and this increase was related to phosphorylation of Akt, AMPK and eNOS. On the other hand, use of NAC reduced superoxide levels and DCF concentration. Reduced superoxide levels and DCF in the exer+NAC group were associated with decreased Akt, AMPK and eNOS phosphorylation. These results appear to be connected with vascular function because VASP phosphorylation increased in acute exercise and decreased in exer+NAC.ConclusionOur results indicate that ROS induced by acute exercise play the important role of activating eNOS, a process apparently mediated by Akt and AMPK
Gold nanoparticles and diclofenac diethylammonium administered by iontophoresis reduce inflammatory cytokines expression in Achilles tendinitis
Marcelo B Dohnert1,2, Mirelli Venâncio1, Jonathann C Possato1, Rodrigo C Zeferino1, Luciana H Dohnert2, Alexandra I Zugno1, Cláudio T De Souza1, Marcos MS Paula1, Thais F Luciano11Postgraduation Program in Health Sciences, Programa de Pós-graduação em Ciências da Saúde PPGCS, Universidade do Extremo Sul Catarinense, Criciúma, Santa Catarina, 2Department of Physiotherapy, Universidade Luterana do Brasil, Torres, Rio Grande do Sul, BrazilIntroduction: Tendinitis affects a substantial number of people in several occupations involving repetitive work or direct trauma. Iontophoresis is a therapeutic alternative used in the treatment of injury during the inflammatory phase. In recent years, gold nanoparticles (GNP) have been studied due to their therapeutic anti-inflammatory capacity and as an alternative to the transport of several proteins. Purpose: This study evaluates the therapeutic effects of iontophoresis using GNPs and diclofenac diethylammonium on inflammatory parameters in rats challenged with traumatic tendinitis.Methods: Wistar rats were divided in three treatment groups (n = 15): (1) iontophoresis + diclofenac diethylammonium; (2) iontophoresis + GNP; and (3) iontophoresis + diclofenac diethylammonium + GNP. External control was formed by challenged tendons without treatment (n = 15). Iontophoresis was administered using 0.3 mA direct current on 1.5 cm² electrodes. Results: The levels of both inflammatory cytokines were significantly higher in untreated challenged rats, when compared with the control (5.398 ± 234 for interleukin 1 beta and 6.411 ± 432 for tumor necrosis factor alpha), which confirms the occurrence of an inflammatory stage in injury (P < 0.05). A significant decrease was observed in expression of cytokines interleukin 1 beta in the three treatment groups, in comparison with untreated challenged tendons, although, in the group treated with diclofenac and GNP, results were similar to the control (1.732 ± 239) (P < 0.05). Concerning tumor necrosis factor alpha, only the group treated with the association diclofenac and GNPs presented decreased levels, compared with the control (3.221 ± 369) (P < 0.05). Conclusion: The results show the efficacy of drug administration using direct current to treat tendinitis in an animal model, and the potential anti-inflammatory, carrier, and enhancing effects of GNPs in iontophoresis.Keywords: tendinous injury, proinflammatory cytokines, electrophoresis, iontophoresis, nanoparticle
Oxidative Damage, Inflammation, and Toll-Like Receptor 4 Pathway Are Increased in Preeclamptic Patients: A Case-Control Study
Problem. There was no direct correlation between plasma and placental oxidative damage parameters and inflammation and evidence of TLR4 pathway activation in the placenta in preeclamptic (PE) patients. Method of Study. 33 PE patients and 33 normotensive pregnant women were included. The maternal section of the placenta and blood were collected to the determination of oxidative damage markers (thiobarbituric acid reactive species and protein carbonyls), inflammatory response (interleukin-6 and myeloperoxidase activity), and activation of the TLR-4-NF-kB pathway. Results. An increase of IL-6 levels in both plasma and placenta was observed, but myeloperoxidase activity was not significantly different comparing the groups. Oxidative damage parameters were increased in plasma and placenta in PE patients. A significant increase of the protein levels of TLR-4 and NF-kB was observed in the placenta. Conclusion. The TLR4-NF-kB pathway is upregulated in PE, probably generating local and systemic inflammatory response that is followed by local and systemic oxidative damage
Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
The Epigenetic Evolution of Glioma Is Determined by the IDH1 Mutation Status and Treatment Regimen
Tumor adaptation or selection is thought to underlie therapy resistance in glioma. To investigate longitudinal epigenetic evolution of gliomas in response to therapeutic pressure, we performed an epigenomic analysis of 132 matched initial and recurrent tumors from patients with IDH-wildtype (IDHwt) and IDH-mutant (IDHmut) glioma. IDHwt gliomas showed a stable epigenome over time with relatively low levels of global methylation. The epigenome of IDHmut gliomas showed initial high levels of genome-wide DNA methylation that was progressively reduced to levels similar to those of IDHwt tumors. Integration of epigenomics, gene expression, and functional genomics identified HOXD13 as a master regulator of IDHmut astrocytoma evolution. Furthermore, relapse of IDHmut tumors was accompanied by histologic progression that was associated with survival, as validated in an independent cohort. Finally, the initial cell composition of the tumor microenvironment varied between IDHwt and IDHmut tumors and changed differentially following treatment, suggesting increased neoangiogenesis and T-cell infiltration upon treatment of IDHmut gliomas. This study provides one of the largest cohorts of paired longitudinal glioma samples with epigenomic, transcriptomic, and genomic profiling and suggests that treatment of IDHmut glioma is associated with epigenomic evolution toward an IDHwt-like phenotype.</p
Geometric effects of sustainable auxetic structures integrating the particle swarm optimization and finite element method
The development of new materials based on industrial wastes has been the focus of much research for a sustainable world. The growing demand for tyres has been every year exacerbating environmental problems due to indiscriminate disposal in the nature, making a potentially harmful waste to public health. The incorporation of rubber particles from scrap tyres into polymeric composites has achieved high toughness and moderate mechanical properties. This work investigates the geometric effects (thickness, width and internal cell angle) of auxetic structures made of recycled rubber composites based on experimental and numerical data. The response surface models integrated with the swarm intelligence and finite element analysis were proposed in order to obtain a range of solutions that provides useful information to the user during the selection of geometric parameters for reentrant cells. The results revealed the cell thickness ranges from 39-40 mm and 5.98-6 mm, and the cell angle range from -0.01 to -0.06º maximize the ultimate strength. The same parameters were able to optimize the modulus of elasticity of rubber auxetic structures, excepting for the angle factor which must be set between -30º and 27.7º. The optimal Poisson's ratio was found when the cell angle ranged from -30º to -28.5º, cell width ranged from 5-5.6 mm and 2 mm in thickness
Enzyme activity of horseradish peroxidase immobilized in chitosan matrices in alternated layers
The successful immobilization of enzymes such as horseradish peroxidase (HRP) in solid films is essential for applications in sensors and for fundamental studies aimed at identifying possible biotechnological devices. in this study we show that HRP can be immobilized in alternated layers with chitosan as the template material. the activity of HRP in HRP/chitosan films was preserved for several weeks, and could be detected optically upon monitoring the reaction with pyrogallol. the morphology of the film displayed stripes that disappeared after reaction with pyrogallol. Though the activity in the HRP/chitosan film was lower than in a homogeneous solution or in an LB film investigated earlier, the response was linear for a considerable period of time, which may be advantageous for sensing hydrogen peroxide. (C) 2009 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Rede BiomatUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, Diadema, SP, BrazilUniv São Paulo, Inst Fis Sao Carlos, Sao Carlos, SP, BrazilUniv Montreal, Ecole Polytech, Montreal, PQ, CanadaUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, Diadema, SP, BrazilWeb of Scienc
Survey of Orchidaceae species of Serra das Cabeças, in Parque Estadual da Serra do Brigadeiro, Araponga-MG, Brazil
Ecology of orchid species was studied, surveyed and characterized on Serra das Cabeças, a subunit of Parque Estadual da Serra do Brigadeiro (PESB), Araponga-MG, Brazil. Data were obtained through monthly visits on all trails of the area, from 2004 to 2014 covering different types of vegetation, collecting some species and identifying them. We observed characteristics such as type of vegetation, habitat where each species was found, intensity of luminosity, altitude and position of plants in relation to watercourses. Obtained results allowed to conclude: 80 species were identified, of which 45 had not been reported for PESB; five for the state of Minas Gerais, and four for Brazilian flora. Concerning habitat, 57.50% are epiphytic, 1.25% hemiepiphytic, 2.50% humic, 15.00% lithophytic and 23.75% terrestrial. Considering vegetation, 52.50% are located in upper montane forest, 1.25% understorey, 10.00% slope forest, 8.75% in transition forest to altitude field, and 27.50% in altitude field. The survey of Orchidaceae species of present study will allow updating the lists of species present in PESB and of Brazilian flora, recorded in Jardim Botânico in Rio de Janeiro State.O estudo trata do levantamento, caracterização e ecologia das espécies de orquídeas da Serra das Cabeças, subunidade do Parque Estadual da Serra do Brigadeiro (PESB), Araponga-MG. Os dados foram obtidos por meio de visitas mensais em todas as trilhas da área, no período de 2004 a 2014 cobrindo os diferentes tipos de vegetação, coletando algumas espécies e identificando-as. Observaram-se características como tipo de vegetação, habitat onde cada espécie foi encontrada, intensidade luminosidade, altitude e posição das plantas em relação a cursos d’água. Os resultados obtidos permitiram concluir: 80 espécies foram identificadas, das quais 45 não haviam sido relatadas para o PESB; cinco para o estado de Minas Gerais e quatro para a flora do Brasil. Quanto ao habitat, 57,50% são epífitas, 1,25% hemiepífitas, 2,50% humícolas, 15,00% rupícolas e 23,75% terrestres. Quanto à vegetação 52,50% encontram-se inseridas em mata altomontano, 1,25% sub-bosque, 10,00% mata de encosta, 8,75% em mata de transição para campo de altitude e 27,50% em campo de altitude. O levantamento das espécies das Orchidaceae do presente trabalho permitirá a atualização das listas de espécies presentes no PESB e da Flora do Brasil, contidos no registro do Jardim Botânico do Rio de Janeiro
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