915 research outputs found

    Bidirectional association between self-reported hypertension and gout: The Singapore Chinese health study

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    It has been hypothesized that the association between hypertension and gout is bidirectional, however, few studies have examined this in a prospective cohort.We analyzed data from the Singapore Chinese Health Study (SCHS) follow-up I (1999-2004) and II (2006-2010) interviews, when both physician-diagnosed hypertension and gout were self-reported. We included participants with data for both follow-up interviews and who were free of heart disease, stroke and cancer at follow-up I. The analysis of hypertension and risk of gout included 31,137 participants when prevalent gout cases were excluded, while the analysis of gout and risk of hypertension included 20,369 participants when prevalent hypertension cases were excluded. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The mean age at follow-up I was 60.1 (SD 7.3) years, and the average follow-up was 6.8 (SD 1.4) years. In the analysis of hypertension and risk of gout, 682 incident cases were identified. Compared to normotensive participants, hypertensive patients had an88% increased risk of developing gout (HR 1.88; 95% CI 1.61-2.21). In the parallel analysis, 5,450 participants reported to have newly diagnosed hypertension during followup. Compared to participants without gout, those with gout had an18% increased risk of developing hypertension (HR 1.18; 95% CI 1.02-1.37). The bidirectional association was stronger in normal weight adults compared to overweight/obese individuals (Pinteraction = 0.06 and 0.04, respectively). The hypertension to gout association was stronger in women compared to men (Pinteraction = 0.04), while the gout to hypertension association was evident in women but not in men (Pinteraction = 0.02). In conclusion, our results suggest that the hypertension-gout association is bidirectional in this cohort of Singapore Chinese adults. The potential interactions of the bidirectional association with obesity and sex deserve further investigations

    Prediction of peptide and protein propensity for amyloid formation

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    Understanding which peptides and proteins have the potential to undergo amyloid formation and what driving forces are responsible for amyloid-like fiber formation and stabilization remains limited. This is mainly because proteins that can undergo structural changes, which lead to amyloid formation, are quite diverse and share no obvious sequence or structural homology, despite the structural similarity found in the fibrils. To address these issues, a novel approach based on recursive feature selection and feed-forward neural networks was undertaken to identify key features highly correlated with the self-assembly problem. This approach allowed the identification of seven physicochemical and biochemical properties of the amino acids highly associated with the self-assembly of peptides and proteins into amyloid-like fibrils (normalized frequency of ÎČ-sheet, normalized frequency of ÎČ-sheet from LG, weights for ÎČ-sheet at the window position of 1, isoelectric point, atom-based hydrophobic moment, helix termination parameter at position j+1 and ΔGÂș values for peptides extrapolated in 0 M urea). Moreover, these features enabled the development of a new predictor (available at http://cran.r-project.org/web/packages/appnn/index.html) capable of accurately and reliably predicting the amyloidogenic propensity from the polypeptide sequence alone with a prediction accuracy of 84.9 % against an external validation dataset of sequences with experimental in vitro, evidence of amyloid formation

    An Evolutionary Trade-Off between Protein Turnover Rate and Protein Aggregation Favors a Higher Aggregation Propensity in Fast Degrading Proteins

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    We previously showed the existence of selective pressure against protein aggregation by the enrichment of aggregation-opposing ‘gatekeeper’ residues at strategic places along the sequence of proteins. Here we analyzed the relationship between protein lifetime and protein aggregation by combining experimentally determined turnover rates, expression data, structural data and chaperone interaction data on a set of more than 500 proteins. We find that selective pressure on protein sequences against aggregation is not homogeneous but that short-living proteins on average have a higher aggregation propensity and fewer chaperone interactions than long-living proteins. We also find that short-living proteins are more often associated to deposition diseases. These findings suggest that the efficient degradation of high-turnover proteins is sufficient to preclude aggregation, but also that factors that inhibit proteasomal activity, such as physiological ageing, will primarily affect the aggregation of short-living proteins

    Microtubular Stability Affects pVHL-Mediated Regulation of HIF-1alpha via the p38/MAPK Pathway in Hypoxic Cardiomyocytes

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    BACKGROUND: Our previous research found that structural changes of the microtubule network influence glycolysis in cardiomyocytes by regulating the hypoxia-inducible factor (HIF)-1α during the early stages of hypoxia. However, little is known about the underlying regulatory mechanism of the changes of HIF-1α caused by microtubule network alternation. The von Hippel-Lindau tumor suppressor protein (pVHL), as a ubiquitin ligase, is best understood as a negative regulator of HIF-1α. METHODOLOGY/PRINCIPAL FINDINGS: In primary rat cardiomyocytes and H9c2 cardiac cells, microtubule-stabilization was achieved by pretreating with paclitaxel or transfection of microtubule-associated protein 4 (MAP4) overexpression plasmids and microtubule-depolymerization was achieved by pretreating with colchicine or transfection of MAP4 siRNA before hypoxia treatment. Recombinant adenovirus vectors for overexpressing pVHL or silencing of pVHL expression were constructed and transfected in primary rat cardiomyocytes and H9c2 cells. With different microtubule-stabilizing and -depolymerizing treaments, we demonstrated that the protein levels of HIF-1α were down-regulated through overexpression of pVHL and were up-regulated through knockdown of pVHL in hypoxic cardiomyocytes. Importantly, microtubular structure breakdown activated p38/MAPK pathway, accompanied with the upregulation of pVHL. In coincidence, we found that SB203580, a p38/MAPK inhibitor decreased pVHL while MKK6 (Glu) overexpression increased pVHL in the microtubule network altered-hypoxic cardiomyocytes and H9c2 cells. CONCLUSIONS/SIGNIFICANCE: This study suggests that pVHL plays an important role in the regulation of HIF-1α caused by the changes of microtubular structure and the p38/MAPK pathway participates in the process of pVHL change following microtubule network alteration in hypoxic cardiomyocytes

    Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay

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    We reconstruct the rare decays B+→K+ÎŒ+Ό−B^+ \to K^+\mu^+\mu^-, B0→K∗(892)0ÎŒ+Ό−B^0 \to K^{*}(892)^0\mu^+\mu^-, and Bs0→ϕ(1020)ÎŒ+Ό−B^0_s \to \phi(1020)\mu^+\mu^- in a data sample corresponding to 4.4fb−14.4 {\rm fb^{-1}} collected in ppˉp\bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} by the CDF II detector at the Fermilab Tevatron Collider. Using 121±16121 \pm 16 B+→K+ÎŒ+Ό−B^+ \to K^+\mu^+\mu^- and 101±12101 \pm 12 B0→K∗0ÎŒ+Ό−B^0 \to K^{*0}\mu^+\mu^- decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the B+B^+ and B0B^0 decay modes, and the K∗0K^{*0} longitudinal polarization in the B0B^0 decay mode with respect to the squared dimuon mass. These are consistent with the theoretical prediction from the standard model, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the Bs0→ϕΌ+Ό−decayandmeasureitsbranchingratioB^0_s \to \phi\mu^+\mu^- decay and measure its branching ratio {\mathcal{B}}(B^0_s \to \phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}using using 27 \pm 6signalevents.Thisiscurrentlythemostrare signal events. This is currently the most rare B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let

    Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons

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    We report measurements of the resonance properties of Lambda_c(2595)+ and Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+ pi+/- final states. These measurements are performed using data corresponding to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. Exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averages for Sigma_c states, and significantly smaller uncertainties than the world averages for excited Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17 pages, 15 figure

    Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV

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    We present a search for a new heavy charged vector boson Wâ€ČW^\prime decaying to an electron-neutrino pair in ppˉp\bar{p} collisions at a center-of-mass energy of 1.96\unit{TeV}. The data were collected with the CDF II detector and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No significant excess above the standard model expectation is observed and we set upper limits on σ⋅B(Wâ€Č→eÎœ)\sigma\cdot{\cal B}(W^\prime\to e\nu). Assuming standard model couplings to fermions and the neutrino from the Wâ€ČW^\prime boson decay to be light, we exclude a Wâ€ČW^\prime boson with mass less than 1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR
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