61 research outputs found

    Uric Acid-Induced Adipocyte Dysfunction Is Attenuated by HO-1 Upregulation: Potential Role of Antioxidant Therapy to Target Obesity

    Get PDF
    Increased uric acid levels have been implicated in the pathogenesis of metabolic syndrome. To examine the mechanisms by which this occurs, we hypothesized that an increase in heme oxygenase 1, a potent antioxidant gene, will decrease uric acid levels and adipocyte dysfunction via suppression of ROS and xanthine oxidase (XO) levels. We examined the effect of uric acid on adipogenesis in human mesenchymal stem cells (MSCs) in the presence and absence of cobalt protoporphyrin (CoPP), an HO-1 inducer, and tin mesoporphyrin (SnMP), an HO activity inhibitor. Uric acid increased adipogenesis by increasing NADPH oxidase expression and elevation in the adipogenesis markers C/EBPα, PPARγ, and Mest, while decreasing small lipid droplets and Wnt10b levels. We treated MSCs with fructose, a fuel source that increases uric acid levels. Our results showed that fructose increased XO expression as compared to the control and concomitant treatment with CoPP significantly decreased XO expression and uric acid levels. These beneficial effects of CoPP were reversed by SnMP, supporting a role for HO activity in mediating these effects. These findings demonstrate that increased levels of HO-1 appear crucial in modulating the phenotype of adipocytes exposed to uric acid and in downregulating XO and NADPH oxidase levels

    Plasma Dynamics

    Get PDF
    Contains reports on three research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-5992)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-4551)National Science Foundation (Grant G-9930)Office of Naval Research through Project SQUID, Phase III, under contract with Massachusetts Institute of Technolog

    Simulation of a Miniature, Low-Power Time-of-Flight Mass Spectrometer for In Situ Analysis of Planetary Atmospheres

    Get PDF
    We are implementing nano- and micro-technologies to develop a miniaturized electron impact ionization mass spectrometer for planetary science. Microfabrication technology is used to fabricate the ion and electron optics, and a carbon nanotube (CNT) cathode is used to generate the ionizing electron beam. Future NASA planetary science missions demand miniaturized, low power mass spectrometers that exhibit high resolution and sensitivity to search for evidence of past and present habitability on the surface and in the atmosphere of priority targets such as Mars, Titan, Enceladus, Venus, Europa, and short-period comets. Toward this objective, we are developing a miniature, high resolution reflectron time-of-flight mass spectrometer (Mini TOF-MS) that features a low-power CNT field emission electron impact ionization source and microfabricated ion optics and reflectron mass analyzer in a parallel-plate geometry that is scalable. Charged particle electrodynamic modeling (SIMION 8.0.4) is employed to guide the iterative design of electron and ion optic components and to characterize the overall performance of the Mini TOF-MS device via simulation. Miniature (less than 1000 cubic centimeters) TOF-MS designs (ion source, mass analyzer, detector only) demonstrate simulated mass resolutions greater than 600 at sensitivity levels on the order of 10(exp -3) cps/molecule N2/cc while consuming 1.3 W of power and are comparable to current spaceflight mass spectrometers. Higher performance designs have also been simulated and indicate mass resolutions approximately 1000, though at the expense of sensitivity and instrument volume

    Excess of L-Alanine in Amino Acids Synthesized in a Plasma Torch Generated by a Hypervelocity Meteorite Impact Reproduced in the Laboratory

    Get PDF
    We present a laboratory reproduction of hypervelocity impacts of a carbon containing meteorite on a mineral substance representative of planetary surfaces. The physical conditions of the resulting impact plasma torch provide favorable conditions for abiogenic synthesis of protein amino acids: We identified glycine and alanine, and in smaller quantities serine, in the produced material. Moreover, we observe breaking of alanine mirror symmetry with L excess, which coincides with the bioorganic world. Therefore the selection of L-amino acids for the formation of proteins for living matter could have been the result from plasma processes occurring during the impact meteorites on the surface. This indicates that the plasma torch from meteorite impacts could play an important role in the formation of biomolecular homochirality. Thus, meteorite impacts possibly were the initial stage of this process and promoted conditions for the emergence of a living matter

    Plasma Dynamics

    Get PDF
    Contains reports on three research projects.Wright Air Development Division (Contract AF33(616)-3984)United States Atomic Energy Commission (Contract AT(30-1)-1842)National Science Foundation (Grant G-9330)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-4551)United States Air Force, Air Force Cambridge Research Center, Air Research and Development Command (Contract AF19(604)-5992

    Plasma Dynamics

    Get PDF
    Contains research objectives and reports on three research projects.National Science Foundation under Grant G-9930Air Force Cambridge Research Center under Contract AF-19(604)-5992WADC Contract AF33(616)-3984, with the Electronic Systems LaboratoryContract AF19(604)-4551 with Air Force Cambridge Research CenterAtomic Energy Commission under Contract AT(30-1)184

    Plasma Dynamics

    Get PDF
    Contains reports on three research projects.National Science Foundation under Grant G-9330Air Force Cambridge Research Center under Contract AF-19(604)-5992United States Air Force (WADD Contract AF33(616)-3984)Contract AF19(604)-4551 with Air Force Cambridge Research CenterAeronautical Accessories Laboratory, Wright Air Development Division, Wright-Patterson Air Force Base, Ohio (Air Force Contract AF33(616)-3984, Project 8149, Task No. 61098)Atomic Energy Commission under Contract AT(30-1)-184

    Plasma Dynamics

    Get PDF
    Contains reports on three research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842)United States Air Force, Air Force Cambridge Research Center, Air Research and Development Command (Contract AF19(604)-5992)National Science Foundation (Grant G-9330)Flight Accessories Laboratory, Wright-Patterson Air Force Base (WADD Contract AF33(616)-3984

    Plasma Dynamics

    Get PDF
    Contains reports on two research projects.National Science Foundation under Grant G-9330WADD Contract AF33(616)-7624 with Flight Accessories Laboratory, Wright-Patterson Air Force Base, OhioAtomic Energy Commission under Contract AT(30-1)-1842Air Force Command and Control Development Division under Contract AF19(604)-599

    Plasma Dynamics

    Get PDF
    Contains research objectives and reports on three research projects.Contract AF19(604)-4551 with Air Force Cambridge Research CenterAtomic Energy Commission under Contract AT(30-1)-1842Air Force Cambridge Research Center under Contract AF19(604)-5992National Science Foundation under Grant G-9330WADD Contract AF33(616)-7624 with Flight Accessories Laboratory, Wright-Patterson Air Force Base, Ohi
    corecore