834 research outputs found

    A unique Kelch domain phosphatase in Plasmodium regulates ookinete morphology, motility and invasion

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    Signalling through post-translational modification (PTM) of proteins is a process central to cell homeostasis, development and responses to external stimuli. The best characterised PTM is protein phosphorylation which is reversibly catalysed at specific residues through the action of protein kinases (addition) and phosphatases (removal). Here, we report characterisation of an orphan protein phosphatase that possesses a domain architecture previously only described in Plantae. Through gene disruption and the production of active site mutants, the enzymatically active Protein Phosphatase containing Kelch-Like domains (PPKL, PBANKA_132950) is shown to play an essential role in the development of an infectious ookinete. PPKL is produced in schizonts and female gametocytes, is maternally inherited where its absence leads to the development of a malformed, immotile, non-infectious ookinete with an extended apical protrusion. The distribution of PPKL includes focussed localization at the ookinete apical tip implying a link between its activity and the correct deployment of the apical complex and microtubule cytoskeleton. Unlike wild type parasites, ppkl(-) ookinetes do not have a pronounced apical distribution of their micronemes yet secretion of microneme cargo is unaffected in the mutant implying that release of microneme cargo is either highly efficient at the malformed apical prominence or secretion may also occur from other points of the parasite, possibly the pellicular pores

    The wMelPop strain of Wolbachia interferes with dopamine levels in Aedes aegypti

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    Wolbachia is an intracellular bacterium that has been stably transinfected into the mosquito vector of dengue, Aedes aegypti. This inherited infection causes a range of metabolic and phenotypic alterations in the mosquito, which might be related to neuronal abnormalities. In order to determine if these alterations were caused by the manipulation of neuroamines by this bacterium, we studied the expression of genes involved in the dopamine biosynthetic pathway and also measured the amount of dopamine in infected and uninfected mosquitoes of different ages. Wolbachia-infected mosquitoes exhibit greater expression of some genes related to the melanization pathway, but not for those directly linked to dopamine production. Although dopamine levels were higher in Wolbachia-positive mosquitoes this was not consistent across all insect ages nor was it related to the previously described Wolbachia induced "bendy" and "shaky" phenotypes

    Survival of patients with prostate cancer and normal PSA levels treated by radical prostatectomy

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    INTRODUCTION: The unpredictability of prostate cancer has become a daily challenge for the urologist, with different strategies being required to manage these cases. In this study, we report on the perspectives for curing prostate cancer in males undergoing radical prostatectomy with Gleason score of 2-6 on prostate biopsy in relation to pre-operative PSA levels. MATERIALS AND METHODS: From 1991 - 2000, we selected 440 individuals whose pathological diagnosis revealed a Gleason score of 2-6 upon prostate biopsy and who subsequently underwent retro-pubic radical prostatectomy due to localized prostate cancer. The clinical stage identified in the group under study was T1c: 206 (46.8%); T2a: 122 (27.7%); T2b: 93 (21.1%); T2c: 17 (3.9%); T3a: 2 (0.5%). Following surgery, we constructed a biochemical recurrence-free survival curve according to pre-operative PSA levels between 0-4; 4.1-10; 10.1-20 and > 20 ng/mL, with a median follow-up of 5 years. RESULTS: Following radical prostatectomy, the pathological stage was confirmed as pT2a: 137 (31.1%); T2b: 118 (26.8%); T2c: 85 (19.3%); T3a: 67 (15.2%); T3b: 6 (1.4%); T3c: 22 (5%). The biochemical recurrence-free survival, according to PSA values between 0-4; 4.1-10; 10.1-20 and > 20 ng/mL, was 86.6%, 62.7%, 39.8% and 24.8% respectively. CONCLUSION: Better chances for curing low-grade prostate cancer occur in individuals with normal PSA for whom a biopsy is not usually recommended.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Department of UrologyUNIFESP, EPM, Department of UrologySciEL

    Identification of a fibrinogen-related protein (FBN9) gene in neotropical anopheline mosquitoes

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    <p>Abstract</p> <p>Background</p> <p>Malaria has a devastating impact on worldwide public health in many tropical areas. Studies on vector immunity are important for the overall understanding of the parasite-vector interaction and for the design of novel strategies to control malaria. A member of the fibrinogen-related protein family, <it>fbn9</it>, has been well studied in <it>Anopheles gambiae </it>and has been shown to be an important component of the mosquito immune system. However, little is known about this gene in neotropical anopheline species.</p> <p>Methods</p> <p>This article describes the identification and characterization of the <it>fbn9 </it>gene partial sequences from four species of neotropical anopheline primary and secondary vectors: <it>Anopheles darlingi, Anopheles nuneztovari, Anopheles aquasalis</it>, and <it>Anopheles albitarsis </it>(namely <it>Anopheles marajoara</it>). Degenerate primers were designed based on comparative analysis of publicly available <it>Aedes aegypti </it>and <it>An. gambiae </it>gene sequences and used to clone putative homologs in the neotropical species. Sequence comparisons and Bayesian phylogenetic analyses were then performed to better understand the molecular diversity of this gene in evolutionary distant anopheline species, belonging to different subgenera.</p> <p>Results</p> <p>Comparisons of the <it>fbn9 </it>gene sequences of the neotropical anophelines and their homologs in the <it>An. gambiae </it>complex (Gambiae complex) showed high conservation at the nucleotide and amino acid levels, although some sites show significant differentiation (non-synonymous substitutions). Furthermore, phylogenetic analysis of <it>fbn9 </it>nucleotide sequences showed that neotropical anophelines and African mosquitoes form two well-supported clades, mirroring their separation into two different subgenera.</p> <p>Conclusions</p> <p>The present work adds new insights into the conserved role of <it>fbn9 </it>in insect immunity in a broader range of anopheline species and reinforces the possibility of manipulating mosquito immunity to design novel pathogen control strategies.</p

    Acute exercise induce endothelial nitric oxide synthase phosphorylation via Akt and AMP-activated protein kinase in aorta of rats: Role of reactive oxygen species

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    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

    Identification and analysis of seven effector protein families with different adaptive and evolutionary histories in plant-associated members of the Xanthomonadaceae.

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    The Xanthomonadaceae family consists of species of non-pathogenic and pathogenic γ-proteobacteria that infect different hosts, including humans and plants. In this study, we performed a comparative analysis using 69 fully sequenced genomes belonging to this family, with a focus on identifying proteins enriched in phytopathogens that could explain the lifestyle and the ability to infect plants. Using a computational approach, we identified seven phytopathogen-enriched protein families putatively secreted by type II secretory system: PheA (CM-sec), LipA/LesA, VirK, and four families involved in N-glycan degradation, NixE, NixF, NixL, and FucA1. In silico and phylogenetic analyses of these protein families revealed they all have orthologs in other phytopathogenic or symbiotic bacteria, and are involved in the modulation and evasion of the immune system. As a proof of concept, we performed a biochemical characterization of LipA from Xac306 and verified that the mutant strain lost most of its lipase and esterase activities and displayed reduced virulence in citrus. Since this study includes closely related organisms with distinct lifestyles and highlights proteins directly related to adaptation inside plant tissues, novel approaches might use these proteins as biotechnological targets for disease control, and contribute to our understanding of the coevolution of plant-associated bacteria

    Quantum mechanical modeling of excited electronic states and their relationship to cathodoluminescence of BaZrO3

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    First-principles calculations set the comprehension over performance of novel cathodoluminescence (CL) properties of BaZrO3 prepared through microwave-assisted hydrothermal. Ground (singlet, s*) and excited (singlet s** and triplet t** ) electronic states were built from zirconium displacement of 0.2 Å in {001} direction. Each ground and excited states were characterized by the correlation of their corresponding geometry with electronic structures and Raman vibrational frequencies which were also identified experimentally. A kind of optical polarization switching was identified by the redistribution of 4dz2 and 4dxz (Zr) orbitals and 2pz O orbital. As a consequence, asymmetric bending and stretching modes theoretically obtained reveal a direct dependence with their polyhedral intracluster and/or extracluster ZrO6 distortions with electronic structure. Then, CL of the as-synthesized BaZrO3 can be interpreted as a result of stable triplet excited states, which are able to trap electrons, delaying the emission process due to spin multiplicity changes

    Reducing occurrence of Giardia duodenalis in children living in semiarid regions: impact of a large scale rainwater harvesting initiative.

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    BACKGROUND: In Brazil, about two million people living in rural semiarid regions were benefited with the construction of rainwater cement cisterns, as an initiative from the program "One Million Cisterns" (P1MC). Nevertheless, few epidemiological studies have been conducted to assess health risks or protection effects associated with consumption of this water source. The aim of this study was to evaluate whether access to rainwater harvesting cisterns is associated with the decrease in the occurrence of Giardia duodenalis infections in children, compared to other children living in households supplied by other water sources. METHODOLOGY/PRINCIPAL FINDINGS: A quasi-experimental study with two concurrent cohorts was developed in two rural municipalities of the semiarid region of Brazil. A sample of 664 children, aged between 4 months and 5 years old, was followed up, of which 332 had access to rainwater cisterns (cistern group) and 332 did not, having water supplied from alternative sources (comparison group). In a period of approximately one year (2010) intestinal parasites were investigated in feces three times. The prevalence of G. duodenalis in children from the cistern group ranged from 4.8 to 10.5%, while the prevalence in the comparison group ranged from 7.6 to 16.7%. Multivariate analysis (GEE) showed a higher risk of G. duodenalis infection in children who did not have access to rainwater cisterns, when compared to children who did (OR 1.72; 95% CI 1.14-2.59). The other variables associated with G. duodenalis infection were: number of rooms per house (OR 0.89; 95% CI 0.80-0.99); family income (OR0.48; 95% CI 0.26-0.88); birth order (OR 1.72; 95% CI 1.17-2.51); preterm children (OR 1.70; 95% CI 1.19-2.43); and improper hand hygiene prior to food preparation (OR 4.78; 95% CI 1.95-11.76). CONCLUSIONS/SIGNIFICANCE: Ownership of a rainwater cistern is associated with a lower prevalence of G. duodenalis infection in children after adjustment for environmental and family-related factors. Nevertheless, the study suggests the necessity to complement physical interventions with actions related to personal and domestic hygiene to enable further reductions in parasite infections affecting mainly the underprivileged populations

    TEMPTOOL - uma ferramenta para a modelagem temporal dos dados

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    O trabalho apresenta uma ferramenta onde o projetista ou o usuário responsável pelas informações temporais de um sistema de informação possa obter todas as estruturas necessárias para a representação do aspecto tempo em seu banco de dados. A ferramenta toma como base a definição do esquema inicial do banco de dados (após a conclusão do projeto de implementação e antes da carga no SGBD). Essa abordagem é baseada no modelo proposto por [Sim98, Rui98]. Existe um projeto (em andamento), para tratar do aperfeiçoamento da ferramenta, para que ela apoie a modelagem temporal dos dados desde o desenvolvimento do modelo conceitual do sistemaÁrea: Ingeniería de Software - Bases de DatosRed de Universidades con Carreras en Informática (RedUNCI
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