352 research outputs found

    Nuclear Calcium Signaling Controls Expression of a Large Gene Pool: Identification of a Gene Program for Acquired Neuroprotection Induced by Synaptic Activity

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    Synaptic activity can boost neuroprotection through a mechanism that requires synapse-to-nucleus communication and calcium signals in the cell nucleus. Here we show that in hippocampal neurons nuclear calcium is one of the most potent signals in neuronal gene expression. The induction or repression of 185 neuronal activity-regulated genes is dependent upon nuclear calcium signaling. The nuclear calcium-regulated gene pool contains a genomic program that mediates synaptic activity-induced, acquired neuroprotection. The core set of neuroprotective genes consists of 9 principal components, termed Activity-regulated Inhibitor of Death (AID) genes, and includes Atf3, Btg2, GADD45β, GADD45γ, Inhibin β-A, Interferon activated gene 202B, Npas4, Nr4a1, and Serpinb2, which strongly promote survival of cultured hippocampal neurons. Several AID genes provide neuroprotection through a common process that renders mitochondria more resistant to cellular stress and toxic insults. Stereotaxic delivery of AID gene-expressing recombinant adeno-associated viruses to the hippocampus confers protection in vivo against seizure-induced brain damage. Thus, treatments that enhance nuclear calcium signaling or supplement AID genes represent novel therapies to combat neurodegenerative conditions and neuronal cell loss caused by synaptic dysfunction, which may be accompanied by a deregulation of calcium signal initiation and/or propagation to the cell nucleus

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Proteinuria Is Associated with Quality of Life and Depression in Adults with Primary Glomerulopathy and Preserved Renal Function

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    BACKGROUND: There is no information about HRQoL, depression and associated factors in adult with nephrotic syndrome-associated glomerulopathy. METHODOLOGY/PRINCIPAL FINDINGS: Patients with primary glomerulopathy where compared with age and sex-matched hemodialysis patients and healthy subjects. Laboratory data, medical history, comorbid conditions were collected to evaluate factors associated with HRQoL (SF-36) and Depression (Hamilton Depression Rating Scale-HAMD). Glomerulopathy patients had low HRQoL in all eight SF-36 domains and two composite scores (physical and mental) in comparison with healthy subjects. HAMD score also was elevated and there was high depression prevalence. Overall, these data were comparable between glomerulopathy and hemodialysis patients. Using multiple regression analysis, factors associated with low HRQoL physical composite score were: last 24 h-urine protein excretion (-0.183, 95%CI -0.223 to -0.710 for each gram of proteinuria, p = 0.01) and cyclosporine use (-15.315, 95%CI -25.913 to -2.717, p = 0.03). Low HRQoL mental composite score was associated with last 24 h-urine protein excretion (-0.157, 95%CI -0.278 to -0.310 for each gram of proteinuria, p = 0.03) and HMAD score was independently associated with age (0.155, 95%CI 0.318 to 0.988 for each year, p = 0.04), female sex (4.788, 95%CI 1.005 to 8.620, 0 = 0.03), disease duration (0.074, 95%CI 0.021 to 0.128 for each month, p = 0.01) and last 24 h-urine protein excretion (0.050, 95%CI 0.018 to 0.085 for each gram of proteinuria, p = 0.02). CONCLUSIONS/SIGNIFICANCE: Nephrotic-syndrome associated glomerulopathy patients have low HRQoL and high prevalence of depression symptoms, comparable with those of hemodialysis patients. Last 24 h-protein excretion rate is independently associated with physical and mental HRQoL domains in addition to depression

    Evidence of niche partitioning under ontogenetic influences among three morphologically similar siluriformes in small subtropical streams

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    Ontogenetic influences in patterns of niche breadth and feeding overlap were investigated in three species of Siluriformes (Heptapterus sp., Rhamdia quelen and Trichomycterus poikilos) aiming at understanding the species coexistence. Samplings were conducted bimonthly by electrofishing technique from June/2012 to June/2013 in ten streams of the northwestern state of Rio Grande do Sul, Brazil. The stomach contents of 1,948 individuals were analyzed by volumetric method, with 59 food items identified. In general Heptapterus sp. consumed a high proportion of Aegla sp., terrestrial plant remains and Megaloptera; R. quelen consumed fish, and Oligochaeta, followed by Aegla sp.; while the diet of T. poikilos was based on Simuliidae, Ephemeroptera and Trichoptera. Specie segregation was observed in the NMDS. Through PERMANOVA analysis feeding differences among species, and between a combination of species plus size classes were observed. IndVal showed which items were indicators of these differences. Niche breadth values were high for all species. The niche breadth values were low only for the larger size of R. quelen and Heptapterus sp. while T. poikilos values were more similar. Overall the species were a low feeding overlap values. The higher frequency of high feeding overlap was observed for interaction between Heptapterus sp. and T. poikilos. The null model confirmed the niche partitioning between the species. The higher frequency of high and intermediate feeding overlap values were reported to smaller size classes. The null model showed resource sharing between the species/size class. Therefore, overall species showed a resource partitioning because of the use of occasional items. However, these species share resources mainly in the early ontogenetic stages until the emphasized change of morphological characteristics leading to trophic niche expansion and the apparent segregation observed

    DNA demethylation pathways: Additional players and regulators.

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    DNA demethylation can occur passively by "dilution" of methylation marks by DNA replication, or actively and independently of DNA replication. Direct conversion of 5-methylcytosine (5mC) to cytosine (C), as originally proposed, does not occur. Instead, active DNA methylation involves oxidation of the methylated base by ten-eleven translocations (TETs), or deamination of the methylated or a nearby base by activation induced deaminase (AID). The modified nucleotide, possibly together with surrounding nucleotides, is then replaced by the BER pathway. Recent data clarify the roles and the regulation of well-known enzymes in this process. They identify base excision repair (BER) glycosylases that may cooperate with or replace thymine DNA glycosylase (TDG) in the base excision step, and suggest possible involvement of DNA damage repair pathways other than BER in active DNA demethylation. Here, we review these new developments

    Integration of Non-market and Market Activities in Cross-border Mergers and Acquisitions

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    Drawing on the resource dependence theory and the resource-based view, this paper investigates the interactions between market and nonmarket activities of firms in the context of the post-merger integration phase in cross-border mergers and acquisitions (M&As). Based on a cross-country survey of 111 M&A practitioners who were personally involved in cross-border M&As around the world, we test seven hypotheses on various market and nonmarket aspects of post-merger integration. We find a positive correlation between buffering strategies and adaptive capabilities in the nonmarket environment, and between bridging and adaptive capabilities in the market environment. However, we could not find any significant correlation between buffering and adaptive capabilities in the market environment, and bridging and adaptive capabilities in the nonmarket environment. We also find that adaptability in the nonmarket environment is positively correlated with adaptability in the market environment, and in turn adaptability in the market environment leads to positive organizational performance of a cross border M&A. These results provide further support for the value of the alignment between market and nonmarket activities and help to fill a gap in the literature on the market-nonmarket interactions in post-merger integration

    Effects of ranolazine on astrocytes and neurons in primary culture

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    Ranolazine (Rn) is an antianginal agent used for the treatment of chronic angina pectoris when angina is not adequately controlled by other drugs. Rn also acts in the central nervous system and it has been proposed for the treatment of pain and epileptic disorders. Under the hypothesis that ranolazine could act as a neuroprotective drug, we studied its effects on astrocytes and neurons in primary culture. We incubated rat astrocytes and neurons in primary cultures for 24 hours with Rn (10−7, 10−6 and 10−5 M). Cell viability and proliferation were measured using trypan blue exclusion assay, MTT conversion assay and LDH release assay. Apoptosis was determined by Caspase 3 activity assay. The effects of Rn on proinflammatory mediators IL-β and TNF-α was determined by ELISA technique, and protein expression levels of Smac/Diablo, PPAR-γ, Mn-SOD and Cu/Zn-SOD by western blot technique. In cultured astrocytes, Rn significantly increased cell viability and proliferation at any concentration tested, and decreased LDH leakage, Smac/Diablo expression and Caspase 3 activity indicating less cell death. Rn also increased anti-inflammatory PPAR-γ protein expression and reduced pro-inflammatory proteins IL-1 β and TNFα levels. Furthermore, antioxidant proteins Cu/Zn-SOD and Mn-SOD significantly increased after Rn addition in cultured astrocytes. Conversely, Rn did not exert any effect on cultured neurons. In conclusion, Rn could act as a neuroprotective drug in the central nervous system by promoting astrocyte viability, preventing necrosis and apoptosis, inhibiting inflammatory phenomena and inducing anti-inflammatory and antioxidant agents
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