28 research outputs found

    Knowledge and attitudes of men to prostate cancer

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    Objective: To ascertain the current level of understanding about prostate cancer (PCa), including treatment options and potential side effects of treatment, among older men. Design and Setting: Questionnaires administered by general practitioners (GPs) in 5 general practices in the Perth metropolitan and regional areas of Western Australia. Participants: Convenience sample of men aged 40-80 years (n=503) with or without prostate cancer presenting for routine consultations. Main outcome measures: Knowledge and attitudes of men to prostate cancer Results: Eighty percent of men did not know the function of the prostate and 48% failed to identify PCa as the most common internal cancer in men. Thirty-five percent had no knowledge of the treatments for PCa and 53% had no knowledge of the side effects of treatments. Asked how they would arrive at a decision about treatment, 70% stated they would ask the GP/specialist for all their options and then decide themselves. Conclusion: This study confirms a deficit in knowledge of the disease among men in the at risk age group. Lack of knowledge encompassed areas which could delay diagnosis and hence treatment. Overall the population preferred some GP/specialist involvement in treatment decision making

    Precise Timing of Transcription by c-di-GMP Coordinates Cell Cycle and Morphogenesis in Caulobacter

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    Bacteria adapt their growth rate to their metabolic status and environmental conditions by modulating the length of their G1 period. Here we demonstrate that a gradual increase in the concentration of the second messenger c-di-GMP determines precise gene expression during G1/S transition in Caulobacter crescentus . We show that c-di-GMP stimulates the kinase ShkA by binding to its central pseudo-receiver domain, activates the TacA transcription factor, and initiates a G1/S-specific transcription program leading to cell morphogenesis and S-phase entry. Activation of the ShkA-dependent genetic program causes c-di-GMP to reach peak levels, which triggers S-phase entry and promotes proteolysis of ShkA and TacA. Thus, a gradual increase of c-di-GMP results in precise control of ShkA-TacA activity, enabling G1/S-specific gene expression that coordinates cell cycle and morphogenesis

    Hybrid histidine kinase activation by cyclic di-GMP-mediated domain liberation

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    Cytosolic hybrid histidine kinases (HHKs) constitute major signaling nodes that control various biological processes, but their input signals and how these are processed are largely unknown. In; Caulobacter crescentus; , the HHK ShkA is essential for accurate timing of the G1-S cell cycle transition and is regulated by the corresponding increase in the level of the second messenger c-di-GMP. Here, we use a combination of X-ray crystallography, NMR spectroscopy, functional analyses, and kinetic modeling to reveal the regulatory mechanism of ShkA. In the absence of c-di-GMP, ShkA predominantly adopts a compact domain arrangement that is catalytically inactive. C-di-GMP binds to the dedicated pseudoreceiver domain Rec1, thereby liberating the canonical Rec2 domain from its central position where it obstructs the large-scale motions required for catalysis. Thus, c-di-GMP cannot only stabilize domain interactions, but also engage in domain dissociation to allosterically invoke a downstream effect. Enzyme kinetics data are consistent with conformational selection of the ensemble of active domain constellations by the ligand and show that autophosphorylation is a reversible process

    Simvastatin add-on to escitalopram in patients with comorbid obesity and major depression (SIMCODE): study protocol of a multicentre, randomised, double-blind, placebo-controlled trial

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    Introduction: Major depressive disorder (MDD) and obesity are both common disorders associated with significant burden of disease worldwide. Importantly, MDD and obesity often co-occur, with each disorder increasing the risk for developing the other by about 50%-60%. Statins are among the most prescribed medications with well-established safety and efficacy. Statins are recommended in primary prevention of cardiovascular disease, which has been linked to both MDD and obesity. Moreover, statins are promising candidates to treat MDD because a meta-analysis of pilot randomised controlled trials has found antidepressive effects of statins as adjunct therapy to antidepressants. However, no study so far has tested the antidepressive potential of statins in patients with MDD and comorbid obesity. Importantly, this is a difficult-to-treat population that often exhibits a chronic course of MDD and is more likely to be treatment resistant. Thus, in this confirmatory randomised controlled trial, we will determine whether add-on simvastatin to standard antidepressant medication with escitalopram is more efficacious than add-on placebo over 12 weeks in 160 patients with MDD and comorbid obesity. Methods and analysis: This is a protocol for a randomised, placebo-controlled, double-blind multicentre trial with parallel-group design (phase II). One hundred and sixty patients with MDD and comorbid obesity will be randomised 1:1 to simvastatin or placebo as add-on to standard antidepressant medication with escitalopram. The primary outcome is change in the Montgomery-angstrom sberg Depression Rating Scale (MADRS) score from baseline to week 12. Secondary outcomes include MADRS response (defined as 50% MADRS score reduction from baseline), MADRS remission (defined as MADRS score <10), mean change in patients' self-reported Beck Depression Inventory (BDI-II) and mean change in high-density lipoprotein, low-density lipoprotein and total cholesterol from baseline to week 12. Ethics and dissemination: This protocol has been approved by the ethics committee of the federal state of Berlin (Ethik-Kommission des Landes Berlin, reference: 19/0226-EK 11) and by the relevant federal authority (Bundesinstitut fur Arzneimittel und Medizinprodukte (BfArM), reference: 4043387). Study findings will be published in peer-reviewed journals and will be presented at (inter)national conferences

    Synthetic vanillate-regulated promoter for graded gene expression in Sphingomonas

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    Regulated promoters are an important basic genetic tool allowing, for example, gene-dosage and gene depletion studies. We have previously described a cumate-inducible promoter (PQ5) that is functional in diverse Alphaproteobacteria. This promoter has been engineered by combining a synthetic minimal promoter, Psyn2, and operator sites and the repressor of the Pseudomonas putida F1 cym/cmt system. In the present study, we engineered a vanillate-regulated promoter using Psyn2 and the regulatory elements of the Caulobacter crescentus vanR-vanAB system. We show that the resulting promoter, which we called PV10, responds rapidly to the inducer vanillate with an induction ratio of about two orders of magnitude in Sphingomonas melonis Fr1. In contrast to the switch-like behavior of PQ5, PV10 shows a linear dose-response curve at intermediate vanillate concentrations, allowing graded gene expression. PV10 is functionally compatible with and independent of PQ5 and cumate, and vice versa, suggesting that both systems can be used simultaneously.ISSN:2045-232

    Regulation of Bacterial Cell Cycle Progression by Redundant Phosphatases

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    In the model organism; Caulobacter crescentus; , a network of two-component systems involving the response regulators CtrA, DivK, and PleD coordinates cell cycle progression with differentiation. Active phosphorylated CtrA prevents chromosome replication in G; 1; cells while simultaneously regulating expression of genes required for morphogenesis and development. At the G; 1; -S transition, phosphorylated DivK (DivK∼P) and PleD (PleD∼P) accumulate to indirectly inactivate CtrA, which triggers DNA replication initiation and concomitant cellular differentiation. The phosphatase PleC plays a pivotal role in this developmental program by keeping DivK and PleD phosphorylation levels low during G; 1; , thereby preventing premature CtrA inactivation. Here, we describe CckN as a second phosphatase akin to PleC that dephosphorylates DivK∼P and PleD∼P in G; 1; cells. However, in contrast to PleC, no kinase activity was detected with CckN. The effects of CckN inactivation are largely masked by PleC but become evident when PleC and DivJ, the major kinase for DivK and PleD, are absent. Accordingly, mild overexpression of; cckN; restores most phenotypic defects of a; pleC; null mutant. We also show that CckN and PleC are proteolytically degraded in a ClpXP-dependent way before the onset of the S phase. Surprisingly, known ClpX adaptors are dispensable for PleC and CckN proteolysis, raising the possibility that as yet unidentified proteolytic adaptors are required for the degradation of both phosphatases. Since; cckN; expression is induced in stationary phase, depending on the stress alarmone (p)ppGpp, we propose that CckN acts as an auxiliary factor responding to environmental stimuli to modulate CtrA activity under suboptimal conditions.; IMPORTANCE; Two-component signal transduction systems are widely used by bacteria to adequately respond to environmental changes by adjusting cellular parameters, including the cell cycle. In; Caulobacter crescentus; , PleC acts as a phosphatase that indirectly protects the response regulator CtrA from premature inactivation during the G; 1; phase of the cell cycle. Here, we provide genetic and biochemical evidence that PleC is seconded by another phosphatase, CckN. The activity of PleC and CckN phosphatases is restricted to the G; 1; phase since both proteins are degraded by ClpXP protease before the G; 1; -S transition. Degradation is independent of any known proteolytic adaptors and relies, in the case of CckN, on an unsuspected N-terminal degron. Our work illustrates a typical example of redundant functions between two-component proteins

    Multiple σEcfG and NepR Proteins Are Involved in the General Stress Response in Methylobacterium extorquens

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    In Alphaproteobacteria, the general stress response (GSR) is controlled by a conserved partner switch composed of the sigma factor σEcfG, its anti-sigma factor NepR and the anti-sigma factor antagonist PhyR. Many species possess paralogues of one or several components of the system, but their roles remain largely elusive. Among Alphaproteobacteria that have been genome-sequenced so far, the genus Methylobacterium possesses the largest number of σEcfG proteins. Here, we analyzed the six σEcfG paralogues of Methylobacterium extorquens AM1. We show that these sigma factors are not truly redundant, but instead exhibit major and minor contributions to stress resistance and GSR target gene expression. We identify distinct levels of regulation for the different sigma factors, as well as two NepR paralogues that interact with PhyR. Our results suggest that in M. extorquens AM1, ecfG and nepR paralogues have diverged in order to assume new roles that might allow integration of positive and negative feedback loops in the regulatory system. Comparison of the core elements of the GSR regulatory network in Methylobacterium species provides evidence for high plasticity and rapid evolution of the GSR core network in this genus

    Untargeted metabolomics links glutathione to bacterial cell cycle progression

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    Cell cycle progression requires the coordination of cell growth, chromosome replication, and division. Consequently, a functional cell cycle must be coupled with metabolism. However, direct measurements of metabolome dynamics remained scarce, in particular in bacteria. Here, we describe an untargeted metabolomics approach with synchronized; Caulobacter crescentus; cells to monitor the relative abundance changes of ~400 putative metabolites as a function of the cell cycle. While the majority of metabolite pools remains homeostatic, ~14% respond to cell cycle progression. In particular, sulfur metabolism is redirected during the G1-S transition, and glutathione levels periodically change over the cell cycle with a peak in late S phase. A lack of glutathione perturbs cell size by uncoupling cell growth and division through dysregulation of KefB, a K; +; /H; +; antiporter. Overall, we here describe the impact of the; C. crescentus; cell cycle progression on metabolism, and in turn relate glutathione and potassium homeostasis to timely cell division

    Characterization of NepR paralogues.

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    <p>A. Interactions between NepR paralogues and PhyR. Co-immunoprecipitation of C-terminal triple FLAG-tagged NepR paralogues. The control strain (WT) bears the empty plasmid pCM80. The input (I), flow-through (FT), last washing step (W) and elution (E) fractions were analyzed by Western blot using anti-PhyR (upper panel) or anti-FLAG (middle panel) antibodies, or stained with Coomassie Blue (lower panel). B. Stress sensitivity of strains overexpressing <i>nepR</i> paralogues. Methylglyoxal sensitivity of the wild-type strains overexpressing <i>nepR</i> (WT/nepR) or one of the putative <i>nepR</i> homologues (WT/1275, WT/2700, WT/735) from the <i>mxaF</i> promoter, or bearing the empty plasmid (WT/80). Data are displayed as means +/- SD of three independent biological replicates. C. Putative σ<sup>EcfG</sup>-dependent promoter of META2_0735. The -35 and -10 boxes are highlighted in grey. D. Activity of the <i>735p</i>::<i>luxCDABE</i> transcriptional fusion in response to ethanol or salt in the wild-type, Δ6 or Δ<i>phyR</i> strain. Values are given as means +/- SD of two independent biological replicates.</p
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