68 research outputs found

    Protein phosphatase 5 regulates titin phosphorylation and function at a sarcomere-associated mechanosensor complex in cardiomyocytes.

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    Serine/threonine protein phosphatase 5 (PP5) is ubiquitously expressed in eukaryotic cells; however, its function in cardiomyocytes is unknown. Under basal conditions, PP5 is autoinhibited, but enzymatic activity rises upon binding of specific factors, such as the chaperone Hsp90. Here we show that PP5 binds and dephosphorylates the elastic N2B-unique sequence (N2Bus) of titin in cardiomyocytes. Using various binding and phosphorylation tests, cell-culture manipulation, and transgenic mouse hearts, we demonstrate that PP5 associates with N2Bus in vitro and in sarcomeres and is antagonistic to several protein kinases, which phosphorylate N2Bus and lower titin-based passive tension. PP5 is pathologically elevated and likely contributes to hypo-phosphorylation of N2Bus in failing human hearts. Furthermore, Hsp90-activated PP5 interacts with components of a sarcomeric, N2Bus-associated, mechanosensor complex, and blocks mitogen-activated protein-kinase signaling in this complex. Our work establishes PP5 as a compartmentalized, well-controlled phosphatase in cardiomyocytes, which regulates titin properties and kinase signaling at the myofilaments

    A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. I. The Large Magellanic Cloud

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    [abridged] We present 52-93 micron spectra obtained with Spitzer in the MIPS-SED mode, of a representative sample of luminous compact far-IR sources in the LMC. These include carbon stars, OH/IR AGB stars, post-AGB objects and PNe, RCrB-type star HV2671, OH/IR red supergiants WOHG064 and IRAS05280-6910, B[e] stars IRAS04530-6916, R66 and R126, Wolf-Rayet star Brey3a, Luminous Blue Variable R71, supernova remnant N49, a large number of young stellar objects, compact HII regions and molecular cores, and a background galaxy (z~0.175). We use the spectra to constrain the presence and temperature of cold dust and the excitation conditions and shocks within the neutral and ionized gas, in the circumstellar environments and interfaces with the surrounding ISM. Evolved stars, including LBV R71, lack cold dust except in some cases where we argue that this is swept-up ISM. This leads to an estimate of the duration of the prolific dust-producing phase ("superwind") of several thousand years for both RSGs and massive AGB stars, with a similar fractional mass loss experienced despite the different masses. We tentatively detect line emission from neutral oxygen in the extreme RSG WOHG064, with implications for the wind driving. In N49, the shock between the supernova ejecta and ISM is revealed by its strong [OI] 63-micron emission and possibly water vapour; we estimate that 0.2 Msun of ISM dust was swept up. Some of the compact HII regions display pronounced [OIII] 88-micron emission. The efficiency of photo-electric heating in the interfaces of ionized gas and molecular clouds is estimated at 0.1-0.3%. We confirm earlier indications of a low nitrogen content in the LMC. Evidence for solid state emission features is found in both young and evolved object; some of the YSOs are found to contain crystalline water ice.Comment: Accepted for publication in The Astronomical Journal. This paper accompanies the Summer 2009 SAGE-Spec release of 48 MIPS-SED spectra, but uses improved spectrum extraction. (Fig. 2 reduced resolution because of arXiv limit.

    The manual pressures of stone tool behaviors and their implications for the evolution of the human hand

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    It is widely agreed that biomechanical stresses imposed by stone tool behaviors influenced the evolution of the human hand. Though archaeological evidence suggests that early hominins participated in a variety of tool behaviors, it is unlikely that all behaviors equally influenced modern human hand anatomy. It is more probable that a behavior's likelihood of exerting a selective pressure was a weighted function of the magnitude of stresses associated with that behavior, the benefits received from it, and the amount of time spent performing it. Based on this premise, we focused on the first part of that equation and evaluated magnitudes of stresses associated with stone tool behaviors thought to have been commonly practiced by early hominins, to determine which placed the greatest loads on the digits. Manual pressure data were gathered from 39 human subjects using a Novel Pliance® manual pressure system while they participated in multiple Plio-Pleistocene tool behaviors: nut-cracking, marrow acquisition with a hammerstone, flake production with a hammerstone, and handaxe and flake use. Manual pressure distributions varied significantly according to behavior, though there was a tendency for regions of the hand subject to the lowest pressures (e.g., proximal phalanges) to be affected less by behavior type. Hammerstone use during marrow acquisition and flake production consistently placed the greatest loads on the digits collectively, on each digit and on each phalanx. Our results suggest that, based solely on the magnitudes of stresses, hammerstone use during marrow acquisition and flake production are the most likely of the assessed behaviors to have influenced the anatomical and functional evolution of the human hand

    A strategy for full interrogation of prognostic gene expression patterns: exploring the biology of diffuse large B cell lymphoma.

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    BackgroundGene expression profiling yields quantitative data on gene expression used to create prognostic models that accurately predict patient outcome in diffuse large B cell lymphoma (DLBCL). Often, data are analyzed with genes classified by whether they fall above or below the median expression level. We sought to determine whether examining multiple cut-points might be a more powerful technique to investigate the association of gene expression with outcome.Methodology/principal findingsWe explored gene expression profiling data using variable cut-point analysis for 36 genes with reported prognostic value in DLBCL. We plotted two-group survival logrank test statistics against corresponding cut-points of the gene expression levels and smooth estimates of the hazard ratio of death versus gene expression levels. To facilitate comparisons we also standardized the expression of each of the genes by the fraction of patients that would be identified by any cut-point. A multiple comparison adjusted permutation p-value identified 3 different patterns of significance: 1) genes with significant cut-point points below the median, whose loss is associated with poor outcome (e.g. HLA-DR); 2) genes with significant cut-points above the median, whose over-expression is associated with poor outcome (e.g. CCND2); and 3) genes with significant cut-points on either side of the median, (e.g. extracellular molecules such as FN1).Conclusions/significanceVariable cut-point analysis with permutation p-value calculation can be used to identify significant genes that would not otherwise be identified with median cut-points and may suggest biological patterns of gene effects

    Cost Reduction of Inhaled Tobramycin by Use of Preservative-Free Intravenous Tobramycin Given via Inhalation

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    This study evaluates drug cost outcomes related to automatic therapeutic substitution of branded tobramycin solution for inhalation (TOBI(®)) with inhaled generic preservative-free intravenous tobramycin (PFIT). A retrospective single-center evaluation of inhaled tobramycin use from 2008 through 2012 was performed. Number of doses dispensed and acquisition costs were obtained. Hourly wage data was acquired, pharmacy production costs were estimated and total cost-savings calculated. Days of therapy (DOTs) were determined for each year. Quality assurance and safety data was collected. In 2008, TOBI(®) drug costs and doses dispensed were 118,665and1769,respectively.FollowingimplementationoftheinterchangeinMay2009,TOBI(®)utilizationceased.PFITcostsin2010through2012averaged118,665 and 1769, respectively. Following implementation of the interchange in May 2009, TOBI(®) utilization ceased. PFIT costs in 2010 through 2012 averaged 34,775 annually and TOBI(®) cost-avoidance exceeded 94,000annuallywhenaccountingforpharmacyproductioncosts,whichweredeterminedtobeatmost94,000 annually when accounting for pharmacy production costs, which were determined to be at most 5.28 per dose. The maximum estimated pharmacy production cost ranged from 8812to8812 to 11,299 annually. PFIT doses dispensed exceeded 1650 each year and annual DOTs ranged from 815 to 1069. The 40-month savings were calculated to be $374,706. Quality assurance and safety data identified one patient who refused PFIT due to odor complaints and one patient who was inappropriately administered a dose orally. Therapeutic substitution of TOBI(®) with PFIT can produce immediate and sustained savings with an acceptable safety profile

    Graphs for each of the 13 genes with a significant logrank statistic (Z-value).

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    <p>On the Y-axis, an unadjusted score statistic of 2 corresponds to a p-value of approximately 0.05. On the X-axis, a value of 0.1 corresponds to the 10<sup>th</sup> percentile of gene expression, 0.2 to the 20<sup>th</sup> percentile, and etc up to the 90<sup>th</sup> percentile of expression. Different cut-point values assessed for each gene are represented by the dots along the connected line of chi-square values. The solid horizontal line represents the 90<sup>th</sup> percentile of the permutation distribution of the maximal score statistics. The range on the x-axis is from 10% to 90% of the distribution of the gene expression variable. An overall p-value adjusted for the permutation analysis is shown along the right sided Y-axis.</p

    Hazard regression functions for the 13 genes with significant cut-points.

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    <p>The Y-axis shows the log of the hazard ratio of death. The X-axis shows the quantile of gene expression. The thin lines show the 90% confidence intervals.</p

    Prognostic genes tested<sup>1</sup>.

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    1<p>Last names with numbers refer to genes that are members of prognostic gene signatures previously reported in A. Rosenwald et al, I. Lossos et al, M. Shipp et al, and M. Tome et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022267#pone.0022267-Rosenwald1" target="_blank">[12]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022267#pone.0022267-Lossos1" target="_blank">[73]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022267#pone.0022267-Shipp2" target="_blank">[74]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022267#pone.0022267-Tome1" target="_blank">[75]</a>.</p
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