Sample records for contract nnc05ca85c task

  1. C-Band Airport Surface Communications System Standards Development, Phase I

    NASA Technical Reports Server (NTRS)

    Hall, Edward; Isaacs, James; Zelkin, Natalie; Henriksen. Steve

    2010-01-01

    This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." The proposed future C-band (5091- to 5150-MHz) airport surface communication system, referred to as the Aeronautical Mobile Airport Communications System (AeroMACS), is anticipated to increase overall air-to-ground data communications systems capacity by using a new spectrum (i.e., not very high frequency (VHF)). Although some critical services could be supported, AeroMACS will also target noncritical services, such as weather advisory and aeronautical information services as part of an airborne System Wide Information Management (SWIM) program. AeroMACS is to be designed and implemented in a manner that will not disrupt other services operating in the C-band. This report defines the AeroMACS concepts of use, high-level system requirements, and architecture; the performance of supporting system analyses; the development of AeroMACS test and demonstration plans; and the establishment of an operational AeroMACS capability in support of C-band aeronautical data communications standards to be advanced in both international (International Civil Aviation Organization, ICAO) and national (RTCA) forums. This includes the development of system parameter profile recommendations for AeroMACS based on existing Institute of Electrical and Electronics Engineering (IEEE) 802.16e- 2009 standards

  2. L-Band Digital Aeronautical Communications System Engineering - Initial Safety and Security Risk Assessment and Mitigation

    NASA Technical Reports Server (NTRS)

    Zelkin, Natalie; Henriksen, Stephen

    2011-01-01

    This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." ITT has completed a safety hazard analysis providing a preliminary safety assessment for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. The assessment was performed following the guidelines outlined in the Federal Aviation Administration Safety Risk Management Guidance for System Acquisitions document. The safety analysis did not identify any hazards with an unacceptable risk, though a number of hazards with a medium risk were documented. This effort represents a preliminary safety hazard analysis and notes the triggers for risk reassessment. A detailed safety hazards analysis is recommended as a follow-on activity to assess particular components of the L-band communication system after the technology is chosen and system rollout timing is determined. The security risk analysis resulted in identifying main security threats to the proposed system as well as noting additional threats recommended for a future security analysis conducted at a later stage in the system development process. The document discusses various security controls, including those suggested in the COCR Version 2.0.

  3. C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 2: Test Bed Performance Evaluation and Final AeroMACS Recommendations

    NASA Technical Reports Server (NTRS)

    Hall, Edward; Magner, James

    2011-01-01

    This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II (this document) describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers.

  4. C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 1: Concepts of Use, Initial System Requirements, Architecture, and AeroMACS Design Considerations

    NASA Technical Reports Server (NTRS)

    Hall, Edward; Isaacs, James; Henriksen, Steve; Zelkin, Natalie

    2011-01-01

    This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I (this document) is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers.

  5. L-Band System Engineering - Concepts of Use, Systems Performance Requirements, and Architecture

    NASA Technical Reports Server (NTRS)

    Henriksen, Stephen; Zelkin, Natalie

    2011-01-01

    This document is being provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-band and L-band Communications Standard Development. Task 7 was motivated by the five year technology assessment performed for the Federal Aviation Administration (FAA) under the joint FAA-EUROCONTROL cooperative research Action Plan (AP-17), also known as the Future Communications Study (FCS). It was based on direction provided by the FAA project-level agreement (PLA FY09_G1M.02-02v1) for "New ATM Requirements-Future Communications." Task 7 was separated into two distinct subtasks, each aligned with specific work elements and deliverable items. Subtask 7-1 addressed C-band airport surface data communications standards development, systems engineering, test bed development, and tests/demonstrations to establish operational capability for what is now referred to as the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2, which is the subject of this report, focused on preliminary systems engineering and support of joint FAA/EUROCONTROL development and evaluation of a future L-band (960 to 1164 MHz) air/ground (A/G) communication system known as the L-band digital aeronautical communications system (L-DACS), which was defined during the FCS. The proposed L-DACS will be capable of providing ATM services in continental airspace in the 2020+ timeframe. Subtask 7-2 was performed in two phases. Phase I featured development of Concepts of Use, high level functional analyses, performance of initial L-band system safety and security risk assessments, and development of high level requirements and architectures. It also included the aforementioned support of joint L-DACS development and evaluation, including inputs to L-DACS design specifications. Phase II provided a refinement of the systems engineering activities performed during Phase I, along with continued joint FAA/EUROCONTROL L-DACS development and evaluation support.

  6. The mibefradil derivative NNC55-0396, a specific T-type calcium channel antagonist, exhibits less CYP3A4 inhibition than mibefradil.

    PubMed

    Bui, Peter H; Quesada, Arnulfo; Handforth, Adrian; Hankinson, Oliver

    2008-07-01

    A novel mibefradil derivative, NNC55-0396, designed to be hydrolysis-resistant, was shown to be a selective T-type Ca(2+) channel inhibitor without L-type Ca(2+) channel efficacy. However, its effects on cytochromes P450 (P450s) have not previously been examined. We investigated the inhibitory effects of NNC55-0396 toward seven major recombinant human P450s--CYP3A4, CYP2D6, CYP1A2, CYP2C9, CYP2C8, CYPC19, and CYP2E1--and compared its effects with those of mibefradil and its hydrolyzed metabolite, Ro40-5966. Our results show that CYP3A4 and CYP2D6 are the two P450s most affected by mibefradil, Ro40-5966, and NNC55-0396. Mibefradil (IC(50) = 33 +/- 3 nM, K(i) = 23 +/- 0.5 nM) and Ro40-5966 (IC(50) = 30 +/- 7.8 nM, K(i) = 21 +/- 2.8 nM) have a 9- to 10-fold greater inhibitory activity toward recombinant CYP3A4 benzyloxy-4-trifluoromethylcoumarin-O-debenzylation activity than NNC55-0396 (IC(50) = 300 +/- 30 nM, K(i) = 210 +/- 6 nM). More dramatically, mibefradil (IC(50) = 566 +/- 71 nM, K(i) = 202 +/- 39 nM) shows 19-fold higher inhibition of CYP3A-associated testosterone 6beta-hydroxylase activity in human liver microsomes compared with NNC55-0396 (IC(50) = 11 +/- 1.1 microM, K(i) = 3.9 +/- 0.4 microM). Loss of testosterone 6beta-hydroxylase activity by recombinant CYP3A4 was shown to be time- and concentration-dependent with both compounds. However, NNC55-0396 (K(I) = 3.87 microM, K(inact) = 0.061/min) is a much less potent mechanism-based inhibitor than mibefradil (K(I) = 83 nM, K(inact) = 0.048/min). In contrast, NNC55-0396 (IC(50) = 29 +/- 1.2 nM, K(i) = 2.8 +/- 0.3 nM) and Ro40-5966 (IC(50) = 46 +/- 11 nM, K(i) = 4.5 +/- 0.02 nM) have a 3- to 4-fold greater inhibitory activity toward recombinant CYP2D6 than mibefradil (IC(50) = 129 +/- 21 nM, K(i) = 12.7 +/- 0.9 nM). Our results suggest that NNC55-0396 could be a more favorable T-type Ca(2+) antagonist than its parent compound, mibefradil, which was withdrawn from the market because of strong inhibition of CYP3A4.

  7. Icing Simulation Research Supporting the Ice-Accretion Testing of Large-Scale Swept-Wing Models

    NASA Technical Reports Server (NTRS)

    Yadlin, Yoram; Monnig, Jaime T.; Malone, Adam M.; Paul, Bernard P.

    2018-01-01

    The work summarized in this report is a continuation of NASA's Large-Scale, Swept-Wing Test Articles Fabrication; Research and Test Support for NASA IRT contract (NNC10BA05 -NNC14TA36T) performed by Boeing under the NASA Research and Technology for Aerospace Propulsion Systems (RTAPS) contract. In the study conducted under RTAPS, a series of icing tests in the Icing Research Tunnel (IRT) have been conducted to characterize ice formations on large-scale swept wings representative of modern commercial transport airplanes. The outcome of that campaign was a large database of ice-accretion geometries that can be used for subsequent aerodynamic evaluation in other experimental facilities and for validation of ice-accretion prediction codes.

  8. Parametric Techniques for Multichannel Signal Processing.

    DTIC Science & Technology

    1985-10-01

    AD-A165 649 PARAMETRIC TECHNIQUES FOR MULTICHANNEL SIGNAL PROCESSING(U) SYSTEM CONTROL TECHNOLOGY INC PALO RLTO CA B FRIEDLANDER OCT 85 5498-87 RRO...CONTRACT NO. DAAG29-83-C-0027 SYSTEMS CONTROL TECHNOLOGY, INC. DT1I? q4 1801 PAGE MILL ROAD ELI PALO ALTO, CALIFORNIA 94304EL C MAR 193 £4 APPROVED FOR...PROJECT, TASK Systems Control Technology, Inc. AREA & WORK UNIT NUMBERS 1801 Page Mill Road Palo Alto, CA 94304 II :ON?’ROLLING OFFICE NAME AND

  9. All Prime Contract Awards by State or Country, Place, and Contractor, FY 85. Part 5 (Arapahoe, Colorado - Washington, D.C.).

    DTIC Science & Technology

    1985-01-01

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  10. Whole-body biodistribution and estimation of radiation-absorbed doses of the dopamine D1 receptor radioligand 11C-NNC 112 in humans.

    PubMed

    Cropley, Vanessa L; Fujita, Masahiro; Musachio, John L; Hong, Jinsoo; Ghose, Subroto; Sangare, Janet; Nathan, Pradeep J; Pike, Victor W; Innis, Robert B

    2006-01-01

    The present study estimated radiation-absorbed doses of the dopamine D(1) receptor radioligand [(11)C]((+)-8-chloro-5-(7-benzofuranyl)-7-hydroxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine) (NNC 112) in humans, based on dynamic whole-body PET in healthy subjects. Whole-body PET was performed on 7 subjects after injection of 710 +/- 85 MBq of (11)C-NNC 112. Fourteen frames were acquired for a total of 120 min in 7 segments of the body. Regions of interest were drawn on compressed planar images of source organs that could be identified. Radiation dose estimates were calculated from organ residence times using the OLINDA 1.0 program. The organs with the highest radiation-absorbed doses were the gallbladder, liver, lungs, kidneys, and urinary bladder wall. Biexponential fitting of mean bladder activity demonstrated that 15% of activity was excreted via the urine. With a 2.4-h voiding interval, the effective dose was 5.7 microSv/MBq (21.1 mrem/mCi). (11)C-NNC 112 displays a favorable radiation dose profile in humans and would allow multiple PET examinations per year to be performed on the same subject.

  11. Prime Contract Awards Alphabetically by Contractor, By State or Country, and Place, FY 84. Part 2. (Bay Area Controls - Cirtech Corporation).

    DTIC Science & Technology

    1984-01-01

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  12. Unsteady Aero Computation of a 1 1/2 Stage Large Scale Rotating Turbine

    NASA Technical Reports Server (NTRS)

    To, Wai-Ming

    2012-01-01

    This report is the documentation of the work performed for the Subsonic Rotary Wing Project under the NASA s Fundamental Aeronautics Program. It was funded through Task Number NNC10E420T under GESS-2 Contract NNC06BA07B in the period of 10/1/2010 to 8/31/2011. The objective of the task is to provide support for the development of variable speed power turbine technology through application of computational fluid dynamics analyses. This includes work elements in mesh generation, multistage URANS simulations, and post-processing of the simulation results for comparison with the experimental data. The unsteady CFD calculations were performed with the TURBO code running in multistage single passage (phase lag) mode. Meshes for the blade rows were generated with the NASA developed TCGRID code. The CFD performance is assessed and improvements are recommended for future research in this area. For that, the United Technologies Research Center's 1 1/2 stage Large Scale Rotating Turbine was selected to be the candidate engine configuration for this computational effort because of the completeness and availability of the data.

  13. Engine Power Turbine and Propulsion Pod Arrangement Study

    NASA Technical Reports Server (NTRS)

    Robuck, Mark; Zhang, Yiyi

    2014-01-01

    A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing spreadsheets that generate gear tooth geometry in Catia 3D environment. Another initial goal was to link information from RomaxDESIGNER (such as hp, rpm, gear ratio) to populate Boeing's parametric weight spreadsheet and create an automated method to estimate drive system weight. This was only partially achieved due to the variety of weight models, number of manual inputs, and qualitative assessments required. A simplified weight spreadsheet was used with data inputs from RomaxDESIGNER along with manual inputs to perform rough weight calculations.

  14. Exchange protein activated by cAMP (Epac) induces vascular relaxation by activating Ca2+-sensitive K+ channels in rat mesenteric artery

    PubMed Central

    Roberts, Owain Llŷr; Kamishima, Tomoko; Barrett-Jolley, Richard; Quayle, John M; Dart, Caroline

    2013-01-01

    Vasodilator-induced elevation of intracellular cyclic AMP (cAMP) is a central mechanism governing arterial relaxation but is incompletely understood due to the diversity of cAMP effectors. Here we investigate the role of the novel cAMP effector exchange protein directly activated by cAMP (Epac) in mediating vasorelaxation in rat mesenteric arteries. In myography experiments, the Epac-selective cAMP analogue 8-pCPT-2′-O-Me-cAMP-AM (5 μm, subsequently referred to as 8-pCPT-AM) elicited a 77.6 ± 7.1% relaxation of phenylephrine-contracted arteries over a 5 min period (mean ± SEM; n= 6). 8-pCPT-AM induced only a 16.7 ± 2.4% relaxation in arteries pre-contracted with high extracellular K+ over the same time period (n= 10), suggesting that some of Epac's relaxant effect relies upon vascular cell hyperpolarization. This involves Ca2+-sensitive, large-conductance K+ (BKCa) channel opening as iberiotoxin (100 nm) significantly reduced the ability of 8-pCPT-AM to reverse phenylephrine-induced contraction (arteries relaxed by only 35.0 ± 8.5% over a 5 min exposure to 8-pCPT-AM, n= 5; P < 0.05). 8-pCPT-AM increased Ca2+ spark frequency in Fluo-4-AM-loaded mesenteric myocytes from 0.045 ± 0.008 to 0.103 ± 0.022 sparks s-1μm-1 (P < 0.05) and reversibly increased both the frequency (0.94 ± 0.25 to 2.30 ± 0.72 s−1) and amplitude (23.9 ± 3.3 to 35.8 ± 7.7 pA) of spontaneous transient outward currents (STOCs) recorded in isolated mesenteric myocytes (n= 7; P < 0.05). 8-pCPT-AM-activated STOCs were sensitive to iberiotoxin (100 nm) and to ryanodine (30 μm). Current clamp recordings of isolated myocytes showed a 7.9 ± 1.0 mV (n= 10) hyperpolarization in response to 8-pCPT-AM that was sensitive to iberiotoxin (n= 5). Endothelial disruption suppressed 8-pCPT-AM-mediated relaxation in phenylephrine-contracted arteries (24.8 ± 4.9% relaxation after 5 min of exposure, n= 5; P < 0.05), as did apamin and TRAM-34, blockers of Ca2+-sensitive, small- and intermediate-conductance K+ (SKCa and IKCa) channels, respectively, and NG-nitro-l-arginine methyl ester, an inhibitor of nitric oxide synthase (NOS). In Fluo-4-AM-loaded mesenteric endothelial cells, 8-pCPT-AM induced a sustained increase in global Ca2+. Our data suggest that Epac hyperpolarizes smooth muscle by (1) increasing localized Ca2+ release from ryanodine receptors (Ca2+ sparks) to activate BKCa channels, and (2) endothelial-dependent mechanisms involving the activation of SKCa/IKCa channels and NOS. Epac-mediated smooth muscle hyperpolarization will limit Ca2+ entry via voltage-sensitive Ca2+ channels and represents a novel mechanism of arterial relaxation. PMID:23959673

  15. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jiao, Feng

    2016-01-01

    This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

  16. PPARδ agonists have opposing effects on insulin resistance in high fat-fed rats and mice due to different metabolic responses in muscle

    PubMed Central

    Ye, Ji-Ming; Tid-Ang, Jennifer; Turner, Nigel; Zeng, Xiao-Yi; Li, Hai-Yan; Cooney, Gregory J; Wulff, Erik Max; Sauerberg, Per; Kraegen, Edward W

    2011-01-01

    BACKGROUND AND PURPOSE The peroxisome proliferator-activated receptor (PPAR)δ has been considered a therapeutic target for diabetes and obesity through enhancement of fatty acid oxidation. The present study aimed to characterize the effects of PPARδ agonists during insulin resistance of the whole body, muscle and liver. EXPERIMENTAL APPROACH Wistar rats and C57BL/J6 mice were fed a high fat diet (HF) and then treated with PPARδ agonists NNC61-5920 and GW501516. The effects on insulin resistance were evaluated by hyperinsulinaemic clamp or glucose tolerance tests combined with glucose tracers. KEY RESULTS In HF rats, 3 weeks of treatment with NNC61-5920 reduced the glucose infusion rate (by 14%, P < 0.05) and glucose disposal into muscle (by 20–30%, P < 0.01) during hyperinsulinaemic clamp. Despite increased mRNA expression of carnitine palmitoyltransferase-1, pyruvate dehydrogenase kinase 4 and uncoupling protein 3 in muscle, plasma and muscle triglyceride levels were raised (P < 0.01). Similar metabolic effects were observed after extended treatment with NNC61-5920 and GW501516 to 6 weeks. However, HF mice treated with NNC61-5920 improved their plasma lipid profile, glucose tolerance and insulin action in muscle. In both HF rats and mice, NNC61-5920 treatment attenuated hepatic insulin resistance and decreased expression of stearoyl-CoA desaturase 1, fatty acid translocase protein CD36 and lipoprotein lipase in liver. CONCLUSIONS AND IMPLICATIONS PPARδ agonists exacerbated insulin resistance in HF rats in contrast to their beneficial effects on metabolic syndrome in HF mice. These opposing metabolic consequences result from their different effects on lipid metabolism and insulin sensitivity in skeletal muscle of these two species. PMID:21265823

  17. PPARδ agonists have opposing effects on insulin resistance in high fat-fed rats and mice due to different metabolic responses in muscle.

    PubMed

    Ye, Ji-Ming; Tid-Ang, Jennifer; Turner, Nigel; Zeng, Xiao-Yi; Li, Hai-Yan; Cooney, Gregory J; Wulff, Erik Max; Sauerberg, Per; Kraegen, Edward W

    2011-06-01

    The peroxisome proliferator-activated receptor (PPAR)δ has been considered a therapeutic target for diabetes and obesity through enhancement of fatty acid oxidation. The present study aimed to characterize the effects of PPARδ agonists during insulin resistance of the whole body, muscle and liver. Wistar rats and C57BL/J6 mice were fed a high fat diet (HF) and then treated with PPARδ agonists NNC61-5920 and GW501516. The effects on insulin resistance were evaluated by hyperinsulinaemic clamp or glucose tolerance tests combined with glucose tracers. In HF rats, 3 weeks of treatment with NNC61-5920 reduced the glucose infusion rate (by 14%, P < 0.05) and glucose disposal into muscle (by 20-30%, P < 0.01) during hyperinsulinaemic clamp. Despite increased mRNA expression of carnitine palmitoyltransferase-1, pyruvate dehydrogenase kinase 4 and uncoupling protein 3 in muscle, plasma and muscle triglyceride levels were raised (P < 0.01). Similar metabolic effects were observed after extended treatment with NNC61-5920 and GW501516 to 6 weeks. However, HF mice treated with NNC61-5920 improved their plasma lipid profile, glucose tolerance and insulin action in muscle. In both HF rats and mice, NNC61-5920 treatment attenuated hepatic insulin resistance and decreased expression of stearoyl-CoA desaturase 1, fatty acid translocase protein CD36 and lipoprotein lipase in liver. PPARδ agonists exacerbated insulin resistance in HF rats in contrast to their beneficial effects on metabolic syndrome in HF mice. These opposing metabolic consequences result from their different effects on lipid metabolism and insulin sensitivity in skeletal muscle of these two species. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  18. Acute exposure to progesterone attenuates cardiac contraction by modifying myofilament calcium sensitivity in the female mouse heart

    PubMed Central

    Feridooni, Hirad A.; MacDonald, Jennifer K.; Ghimire, Anjali; Pyle, W. Glen

    2017-01-01

    Acute application of progesterone attenuates cardiac contraction, although the underlying mechanisms are unclear. We investigated whether progesterone modified contraction in isolated ventricular myocytes and identified the Ca2+ handling mechanisms involved in female C57BL/6 mice (6–9 mo; sodium pentobarbital anesthesia). Cells were field-stimulated (4 Hz; 37°C) and exposed to progesterone (0.001–10.0 μM) or vehicle (35 min). Ca2+ transients (fura-2) and cell shortening were recorded simultaneously. Maximal concentrations of progesterone inhibited peak contraction by 71.4% (IC50 = 160 ± 50 nM; n = 12) and slowed relaxation by 75.4%. By contrast, progesterone had no effect on amplitudes or time courses of underlying Ca2+ transients. Progesterone (1 µM) also abbreviated action potential duration. When the duration of depolarization was controlled by voltage-clamp, progesterone attenuated contraction and slowed relaxation but did not affect Ca2+ currents, Ca2+ transients, sarcoplasmic reticulum (SR) content, or fractional release of SR Ca2+. Actomyosin MgATPase activity was assayed in myofilaments from hearts perfused with progesterone (1 μM) or vehicle (35 min). While maximal responses to Ca2+ were not affected by progesterone, myofilament Ca2+ sensitivity was reduced (EC50 = 0.94 ± 0.01 µM for control, n = 7 vs. 1.13 ± 0.05 μM for progesterone, n = 6; P < 0.05) and progesterone increased phosphorylation of myosin binding protein C. The effects on contraction were inhibited by lonaprisan (progesterone receptor antagonist) and levosimendan (Ca2+ sensitizer). Unlike results in females, progesterone had no effect on contraction or myofilament Ca2+ sensitivity in age-matched male mice. These data indicate that progesterone reduces myofilament Ca2+ sensitivity in female hearts, which may exacerbate manifestations of cardiovascular disease late in pregnancy when progesterone levels are high. NEW & NOTEWORTHY We investigated myocardial effects of acute application of progesterone. In females, but not males, progesterone attenuates and slows cardiomyocyte contraction with no effect on calcium transients. Progesterone also reduces myofilament calcium sensitivity in female hearts. This may adversely affect heart function, especially when serum progesterone levels are high in pregnancy. Listen to this article’s corresponding podcast at https://ajpheart.podbean.com/e/acute-progesterone-modifies-cardiac-contraction/. PMID:27793852

  19. Calcium Channels, Rho-Kinase, Protein Kinase-C, and Phospholipase-C Pathways Mediate Mercury Chloride-Induced Myometrial Contractions in Rats.

    PubMed

    Koli, Swati; Prakash, Atul; Choudhury, Soumen; Mandil, Rajesh; Garg, Satish K

    2018-05-21

    Adverse effects of mercury on female reproduction are reported; however, its effect on myogenic activity of uterus and mechanism thereof is obscure. Present study was undertaken to unravel the mechanistic pathways of mercuric chloride (HgCl 2 )-induced myometrial contraction in rats. Isometric tension in myometrial strips of rats following in vitro exposure to HgCl 2 was recorded using data acquisition system-based physiograph. HgCl 2 produced concentration-dependent (10 nM-100 μM) uterotonic effect which was significantly (p < 0.05) reduced in Ca 2+ -free solution and inhibited in the presence of nifedipine (1 μM), a L-type Ca 2+ channel blocker, thus suggesting the importance of extracellular Ca 2+ and its entry through L-type calcium channels in HgCl 2 -induced myometrial contractions in rats. Cumulative concentration-response curve of HgCl 2 was significantly (p < 0.05) shifted towards right in the presence of Y-27632 (10 μM), a Rho-kinase inhibitor, suggesting the involvement of Ca 2+ -sensitization pathway in mediating HgCl 2 -induced myometrial contraction. HgCl 2 -induced myometrial contraction was also significantly (p < 0.05) inhibited in the presence of methoctramine or para-fluoro-hexahydro-siladifenidol, a selective M 2 and M 3 receptor antagonists, respectively, which evidently suggest that mercury also interacts with M 2 and M 3 muscarinic receptors to produce myometrial contractions. U-73122 and GF-109203X, the respective inhibitors of PLC and PKC-dependent pathways, downstream to the receptor activation, also significantly (p < 0.05) attenuated the uterotonic effect of HgCl 2 on rat uterus. Taken together, present study evidently reveals that HgCl 2 interacts with muscarinic receptors and activates calcium signaling cascades involving calcium channels, Rho-kinase, protein kinase-C, and phospholipase-C pathways to exert uterotonic effect in rats. Graphical Abstract Graphical abstract depicting the mechanism of mercury-induced myometrial contraction in rats. M receptor: Muscarinic receptor; PIP2: phospho-inositol bisphosphate; PLC: phospholipase-C; DAG: diacyl glycerol; IP3: inositol triphosphate; IP3R: inositol triphosphate receptor; PKC; protein kinase-C; MLCP: myosin light chain phosphatise; MYPT: myosin phosphatase; SR: sarco-endoplasmic reticulum.

  20. Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane.

    PubMed

    Han, Xue; Ke, Jie; Suleiman, Norhidayah; Levason, William; Pugh, David; Zhang, Wenjian; Reid, Gillian; Licence, Peter; George, Michael W

    2016-06-07

    We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

  1. Headquarters Task Group 8.5 Operation Plan 2-1-62 Operation Order 2-1-62, Effective ____1962 for Operation Dominic

    DTIC Science & Technology

    1962-03-22

    1-62 Operation Order 2-1-62, Effective ____1962 for Operation Dominic 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...q TG-8.5, 15 Jan 62 co Camand Program Schedule, Eq JTF-8, 17 Jan 62 d. m, Mractor IMA to Wartagcr AID, f i l e referr82 HA-DA-DBA Qtcd l 8 Dec...Establishing the basic secur i ty program of TG 8.5. (c) Developing and dirreminating secur i ty measure8 for action by !CG 8.5 elements. (d) Providing c

  2. Juxtaposition of the changes in intracellular calcium and force during staircase potentiation at 30 and 37°C

    PubMed Central

    Vandenboom, Rene

    2014-01-01

    Ca2+ entry during the action potential stimulates muscle contraction. During repetitive low frequency stimulation, skeletal muscle undergoes staircase potentiation (SP), a progressive increase in the peak twitch force induced by each successive stimulus. Multiple mechanisms, including myosin regulatory light chain phosphorylation, likely contribute to SP, a temperature-dependent process. Here, we used the Ca2+-sensitive fluorescence indicators acetoxymethyl (AM)-furaptra and AM-fura-2 to examine the intracellular Ca2+ transient (ICT) and the baseline Ca2+ level at the onset of each ICT during SP at 30 and 37°C in mouse lumbrical muscle. The stimulation protocol, 8 Hz for 8 s, resulted in a 27 ± 3% increase in twitch force at 37°C and a 7 ± 2% decrease in twitch force at 30°C (P < 0.05). Regardless of temperature, the peak rate of force production (+df/dt) was higher in all twitches relative to the first twitch (P < 0.05). Consistent with the differential effects of stimulation on twitch force at the two temperatures, raw ICT amplitude decreased during repetitive stimulation at 30°C (P < 0.05) but not at 37°C. Cytosolic Ca2+ accumulated during SP such that baseline Ca2+ at the onset of ICTs occurring late in the train was higher (P < 0.05) than that of those occurring early in the train. ICT duration increased progressively at both temperatures. This effect was not entirely proportional to the changes in twitch duration, as twitch duration characteristically decreased before increasing late in the protocol. This is the first study identifying a changing ICT as an important, and temperature-sensitive, modulator of muscle force during repetitive stimulation. Moreover, we extend previous observations by demonstrating that contraction-induced increases in baseline Ca2+ coincide with greater +df/dt but not necessarily with higher twitch force. PMID:25422504

  3. Synthesis and thermoelectric property of Ca and In-doped n-type Bi85Sb15 alloy

    NASA Astrophysics Data System (ADS)

    Kadel, Kamal; Li, Wenzhi; Joshi, Giri; Ren, Zhifeng

    2014-03-01

    In the present work we investigated the thermo-electric properties of undoped Bi85Sb15 and different Ca-doped Bi85Sb15Cax (x =0.5, 2, and 5) and In-doped Bi85Sb15Inx(x =0.5, 2) alloys synthesized via arc-melting first and followed by ball milling and hot pressing. Effect of different Ca and In doping levels on transport properties of Bi85Sb15 alloys has been investigated. It is found that thermal conductivity decreases with increasing Ca and decreasing In. Electrical transport measurements show that power factor increases with doping level of Ca up to Bi85Sb15Ca2 and then decreases yielding the maximum power factor of 3.8 × 10-3 Wm-1K-2 and zT of 0.39 at room temperature for Bi85Sb15Ca2. For indium doping, power factor decreases with doping level from 0.5 to 2, yielding the maximum zT value of 0.37 at room temperature for Bi85Sb15In0.5. In this work, calcium doping in Bi85Sb15 alloy is found to yield better thermoelectric property than indium doping.

  4. Deals Among Rational Agents,

    DTIC Science & Technology

    1985-03-01

    ARD-AI57 966 DEALS AMONG RATIONAL AGENTS(U) STANFORD UNIV CA DEPT OF 1/1lit COMPUTER SCIENCE J S ROSENSCHEIN ET AL. MAR 857 STAN-CS-85-1e42 NOO039-83... Rational Agents by Jeffrey S. Rosenschemn Michael R. Genesereth Contract N00039-83-c-0136 Department of Computer Science Stanford University Stanford, CA... Rational Agents Jeffrey S. Rosenschein Michael R. Genesereth COMPUTER SCIENCE DEPARTME NT Stanford University Sta-;!ord, California 94305 A ~ ,2 TA

  5. Radiation dose reduction in digital breast tomosynthesis (DBT) by means of deep-learning-based supervised image processing

    NASA Astrophysics Data System (ADS)

    Liu, Junchi; Zarshenas, Amin; Qadir, Ammar; Wei, Zheng; Yang, Limin; Fajardo, Laurie; Suzuki, Kenji

    2018-03-01

    To reduce cumulative radiation exposure and lifetime risks for radiation-induced cancer from breast cancer screening, we developed a deep-learning-based supervised image-processing technique called neural network convolution (NNC) for radiation dose reduction in DBT. NNC employed patched-based neural network regression in a convolutional manner to convert lower-dose (LD) to higher-dose (HD) tomosynthesis images. We trained our NNC with quarter-dose (25% of the standard dose: 12 mAs at 32 kVp) raw projection images and corresponding "teaching" higher-dose (HD) images (200% of the standard dose: 99 mAs at 32 kVp) of a breast cadaver phantom acquired with a DBT system (Selenia Dimensions, Hologic, CA). Once trained, NNC no longer requires HD images. It converts new LD images to images that look like HD images; thus the term "virtual" HD (VHD) images. We reconstructed tomosynthesis slices on a research DBT system. To determine a dose reduction rate, we acquired 4 studies of another test phantom at 4 different radiation doses (1.35, 2.7, 4.04, and 5.39 mGy entrance dose). Structural SIMilarity (SSIM) index was used to evaluate the image quality. For testing, we collected half-dose (50% of the standard dose: 32+/-14 mAs at 33+/-5 kVp) and full-dose (standard dose: 68+/-23 mAs at 33+/-5 kvp) images of 10 clinical cases with the DBT system at University of Iowa Hospitals and Clinics. NNC converted half-dose DBT images of 10 clinical cases to VHD DBT images that were equivalent to full dose DBT images. Our cadaver phantom experiment demonstrated 79% dose reduction.

  6. Neurotoxicity Induced by Bupivacaine via T-Type Calcium Channels in SH-SY5Y Cells

    PubMed Central

    Wen, Xianjie; Xu, Shiyuan; Liu, Hongzhen; Zhang, Quinguo; Liang, Hua; Yang, Chenxiang; Wang, Hanbing

    2013-01-01

    There is concern regarding neurotoxicity induced by the use of local anesthetics. A previous study showed that an overload of intracellular calcium is involved in the neurotoxic effect of some anesthetics. T-type calcium channels, which lower the threshold of action potentials, can regulate the influx of calcium ions. We hypothesized that T-type calcium channels are involved in bupivacaine-induced neurotoxicity. In this study, we first investigated the effects of different concentrations of bupivacaine on SH-SY5Y cell viability, and established a cell injury model with 1 mM bupivacaine. The cell viability of SH-SY5Y cells was measured following treatment with 1 mM bupivacaine and/or different dosages (10, 50, or 100 µM) of NNC 55-0396 dihydrochloride, an antagonist of T-type calcium channels for 24 h. In addition, we monitored the release of lactate dehydrogenase, cytosolic Ca2+ ([Ca2+]i), cell apoptosis and caspase-3 expression. SH-SY5Y cells pretreated with different dosages (10, 50, or 100 µM) of NNC 55-0396 dihydrochloride improved cell viability, reduced lactate dehydrogenase release, inhibited apoptosis, and reduced caspase-3 expression following bupivacaine exposure. However, the protective effect of NNC 55-0396 dihydrochloride plateaued. Overall, our results suggest that T-type calcium channels may be involved in bupivacaine neurotoxicity. However, identification of the specific subtype of T calcium channels involved requires further investigation. PMID:23658789

  7. Somatostatin receptor subtype-4 agonist NNC 26-9100 mitigates the effect of soluble Aβ(42) oligomers via a metalloproteinase-dependent mechanism.

    PubMed

    Sandoval, Karin E; Farr, Susan A; Banks, William A; Crider, Albert M; Morley, John E; Witt, Ken A

    2013-07-03

    Soluble amyloid-β peptide (Aβ) oligomers have been hypothesized to be primary mediators of Alzheimer's disease progression. In this regard, reduction of soluble Aβ-oligomers levels within the brain may provide a viable means in which to treat the disease. Somatostatin receptor subtype-4 (SSTR4) agonists have been proposed to reduce Aβ levels in the brain via enhancement of enzymatic degradation. Herein we evaluated the effect of selective SSTR4 agonist NNC 26-9100 on the changes in learning and soluble Aβ42 oligomer brain content with and without co-administration of the M13-metalloproteinase family enzyme-inhibitor phosphoramidon, using the senescence-accelerated mouse prone-8 (SAMP8) model. NNC 26-9100 treatment (0.2 µg i.c.v. in 2 µL) improved learning, which was blocked by phosphoramidon (1 and 10mM, respectively). NNC 26-9100 decreased total soluble Aβ42, an effect which was blocked by phosphoramidon (10mM). Extracellular, intracellular, and membrane fractions were then isolated from cortical tissue and assessed for soluble oligomer alterations. NNC 26-9100 decreased the Aβ42 trimeric (12 kDa) form within the extracellular and intracellular fractions, and produced a band-split effect of the Aβ42 hexameric (25 kDa) form within the extracellular fraction. These effects were also blocked by phosphoramdon (1 and 10mM, respectively). Subsequent evaluation of NNC 26-9100 in APPswe Tg2576 transgenic mice showed a similar learning improvement and corresponding reduction in soluble Aβ42 oligomers within extracellular, intracellular, and membrane fractions. These data support the hypothesis that NNC 26-9100 reduces soluble Aβ42 oligomers and enhances learning through a phosphoramidon-sensitive metalloproteinase-dependent mechanism. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Acute toxicity and antispasmodic activities of Achillea wilhelmsii C. Koch.

    PubMed

    Ali, Niaz; Shah, Syed Wadood Ali; Ahmed, Ghayour; Shah, Ismail; Shoaib, Mohammad; Junaid, Muhammad; Ali, Waqar

    2014-03-01

    Since Achillea wilhelmsii is used as antispasmodic in traditional medicine, we conducted our current work to investigate its rationale on scientific grounds. Acute toxicity studies of crude methanol extract of Achillea wilhelmsii (Aw. CMeOH) is also performed. Effect of Aw. CMeOH and its fractions were tested on isolated sections of rabbits' jejunum at test concentrations 0.01, 0.03, 1.0, 3.0, 5.0 and 10mg/ml. The test extracts, in similar concentrations, were also tested on KCl-induced contractions. Calcium chloride curves were constructed for those fractions which relaxed KCl induced contractions in the absence and presence of the test samples to investigate its possible mode of action through calcium channels. Aw. CMeOH tested positive for flavonoids, saponins, tannins, glycosides, terpenoids, sterols, phenols, carbohydrates and proteins. LD(50) for acute toxicity studies is 2707±12.6 mg/kg. Mean EC(50) values for Aw. CMeOH on spontaneous and KCl-induced contractions are 3.41±0.18 (2.56-3.8, n=6) and 0.68±0.05 (0.6-0.85, n=6) mg/ml, respectively. Respective EC(50) values for n-hexane fraction on spontaneous and KCl-induced contractions are 3.06±0.08 (2.8-3.3, n=6) and 1.68±0.8 (1.4-1.9, n=6) mg/ml, respectively. Corresponding EC(50) (mg/ml) values for chloroformic, ethylacetate and aqueous fractions of Achillea wilhelmsii on spontaneous rabbits' jejunum preparations are 4.8±0.2 (4.41-5.63, n=6), 5.07±0.15 (4.7-5.58, n=6) and 5.2±0.13 (4.91-5.64, n=4), respectively. Constructing calcium chloride curves, in the presence of 0.1 mg/ml of Aw. CMeOH, mean EC(50) value (log molar [Ca(++)]) is-1.98±0.03 (-1.89-2.05, n=6) vs. control EC(50) (log molar [Ca(++)])-2.41±0.02 (-2.32-2.44, n=6). Mean EC(50) value (log molar [Ca(++)]) for 0.3 mg/ml n-hexane fraction is-1.76±0.05 (-1.70 -1.93, n=6) vs. control EC(50) (log molar [Ca(++)]) value-2.18±0.07 (-2.0-2.46, n=6). While in the presence of chloroformic fraction (3 mg/ml), mean EC(50) (log molar [Ca(++)]) value is -2.4±0.1 (-2.78 -2.9, n=6) vs. control EC(50) (log molar [Ca(++)]) value-2.70±0.05 (-2.5-2.8, n=6). Mean EC(50) value (log molar [Ca(++)]) for ethyl acetate fraction (1 mg/ml) is-1.94±0.07 (-1.75-2.05, n=6) vs. control EC(50) (log molar [Ca(++)]) value-2.69±0.04 (-2.57-2.79, n=6). Mean EC(50) (log molar [Ca(++)]) value for residual aqueous fraction (3 mg/ml) is-1.8±0.3 (-1.71-1.84, n=6) vs. control EC(50) (log molar [Ca(++)]) -2.6±0.04 (-2.59-2.76, n=6). Whereas, the verapamil (0.1µM) EC(50) value (log molar [Ca(++)]) is-1.7±0.1 (-1.6-1.8, n=6) vs. control EC(50) value (log molar [Ca(++)])- 2.4±0.09 (-2.3-2.47, n=6). The present research work confirms that the intestinal relaxation effect of Achillea wilhelmsii is supporting its traditional use as antispasmodic. The plant species can be a source for calcium antagonist(s), which can preferably be isolated from n-hexane fraction.

  9. Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles.

    PubMed

    Plant, David R; Lynch, Gordon S; Williams, David A

    2002-03-15

    The effect of exogenous hydrogen peroxide (H(2)O(2)) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mM H(2)O(2) diminished the ability of the Ca(2+)-depleted SR to reload Ca(2+) in both slow (P < 0.01) and fast twitch fibres (P < 0.05) compared to control. Under conditions when all Ca(2+) uptake was prevented, 1 mM H(2)O(2) increased SR Ca(2+) "leak" in fast twitch fibres by 24 +/- 5 % (P < 0.05), but leak was not altered in slow twitch fibres. Treatment with 1 mM H(2)O(2) also increased the peak force of low [caffeine] contracture by approximately 45% in both fibre types compared to control (P < 0.01), which could be partly reversed following treatment with 10 mM dithiothreitol (DTT). The changes in SR function caused by 1 mM H(2)O(2) were associated with an approximately 65% increase in the peak height of depolarization-induced contractile response (DICR) in slow twitch fibres, compared to control (no H(2)O(2); P < 0.05). In contrast, peak contractile force of fast twitch fibres was not altered by 1 mM H(2)O(2) treatment. Equilibration with 5 mM H(2)O(2) induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mM DTT. Peak DICR was also increased approximately 40% by 5 mM H(2)O(2) in slow twitch fibres compared to control (no H(2)O(2); P < 0.05). Our results indicate that exogenous H(2)O(2) increases depolarization-induced contraction of mechanically skinned slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca(2+) release during contraction and/or an increase in Ca(2+) sensitivity.

  10. Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles

    PubMed Central

    Plant, David R; Lynch, Gordon S; Williams, David A

    2002-01-01

    The effect of exogenous hydrogen peroxide (H2O2) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mm H2O2 diminished the ability of the Ca2+-depleted SR to reload Ca2+ in both slow (P < 0.01) and fast twitch fibres (P < 0.05) compared to control. Under conditions when all Ca2+ uptake was prevented, 1 mm H2O2 increased SR Ca2+ ‘leak’ in fast twitch fibres by 24 ± 5 % (P < 0.05), but leak was not altered in slow twitch fibres. Treatment with 1 mm H2O2 also increased the peak force of low [caffeine] contracture by ∼45 % in both fibre types compared to control (P < 0.01), which could be partly reversed following treatment with 10 mm dithiothreitol (DTT). The changes in SR function caused by 1 mm H2O2 were associated with an ∼65 % increase in the peak height of depolarization-induced contractile response (DICR) in slow twitch fibres, compared to control (no H2O2; P < 0.05). In contrast, peak contractile force of fast twitch fibres was not altered by 1 mm H2O2 treatment. Equilibration with 5 mm H2O2 induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mm DTT. Peak DICR was also increased ∼40 % by 5 mm H2O2 in slow twitch fibres compared to control (no H2O2; P < 0.05). Our results indicate that exogenous H2O2 increases depolarization-induced contraction of mechanically skinned slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca2+ release during contraction and/or an increase in Ca2+ sensitivity. PMID:11897857

  11. Synthesis and thermoelectric property of Ca-doped n-type Bi85 Sb 15 alloy

    NASA Astrophysics Data System (ADS)

    Kadel, Kamal; Li, Wenzhi; Joshi, Giri; Ren, Zhifeng

    2011-03-01

    Bi 1-x Sb x (0.09 x 0.20) alloysaren - typesemiconductingmaterialsthatexhibitagoodthermoelectricpropertyatlowtemperature , around 80 K . InthepresentworkweinvestigatedthethermoelectricpropertiesofundopedBi 85 Sb 15 anddifferentCa - dopedBi 85 Sb 15 Ca x alloys (x = 0.5 , 2 , and 5) synthesizedviaarc - meltingfirstandfollowedbyballmillingandhotpressing . EffectofdifferentCadopinglevelsontransportpropertiesofBi 85 Sb 15 alloyshasbeeninvestigated . ItisfoundthatthermalconductivitydecreaseswithincreasingCa . ElectricaltransportmeasurementsshowthatpowerfactorincreaseswithdopinglevelofCauptoBi 85 Sb 15 Ca 2 andthendecreases , yieldingthemaximumvalueofpowerfactorof 3.8 × 10 -3 Wm -1 K -2 andZTof 0.39 atroomtemperatureforBi 85 Sb 15 Ca 2 . Properties at below room temperature will also be presented.

  12. Antagonistic targeting of the histamine H3 receptor decreases caloric intake in higher mammalian species.

    PubMed

    Malmlöf, Kjell; Hastrup, Sven; Wulff, Birgitte Schellerup; Hansen, Barbara C; Peschke, Bernd; Jeppesen, Claus Bekker; Hohlweg, Rolf; Rimvall, Karin

    2007-04-15

    The main purpose of this study was to examine the effects of a selective histamine H(3) receptor antagonist, NNC 38-1202, on caloric intake in pigs and in rhesus monkeys. The compound was given intragastrically (5 or 15 mg/kg), to normal pigs (n=7) and subcutaneously (1 or 0.1mg/kg) to obese rhesus monkeys (n=9). The energy intake recorded following administration of vehicle to the same animals served as control for the effect of the compound. In addition, rhesus monkey and pig histamine H(3) receptors were cloned from hypothalamic tissues and expressed in mammalian cell lines. The in vitro antagonist potencies of NNC 38-1202 at the H(3) receptors were determined using a functional GTPgammaS binding assay. Porcine and human H(3) receptors were found to have 93.3% identity at the amino acid level and the close homology between the monkey and human H(3) receptors (98.4% identity) was confirmed. The antagonist potencies of NNC 38-1202 at the porcine, monkey and human histamine H(3) receptors were high as evidenced by K(i)-values being clearly below 20 nM, whereas the K(i)-value on the rat H(3) receptor was significantly higher (56+/-6.0 nM). NNC 38-1202, given to pigs in a dose of 15 mg/kg, produced a significant (p<0.05) reduction (55%) of calorie intake compared with vehicle alone, (132.6+/-10.0 kcal/kgday versus 59.7+/-10.2 kcal/kgday). In rhesus monkeys administration of 0.1 and 1mg/kg decreased (p<0.05) average calorie intakes by 40 and 75%, respectively. In conclusion, the present study demonstrates that antagonistic targeting of the histamine H(3) receptor decreases caloric intake in higher mammalian species.

  13. Increase in endothelial cell Ca2+ in response to mouse cremaster muscle contraction

    PubMed Central

    Duza, Tasmia; Sarelius, Ingrid H

    2004-01-01

    We addressed the role of endothelial cells (ECs) in metabolic dilatation of skeletal muscle arterioles in anaesthetized mice in situ. Electrical field stimulation was used to contract the cremaster muscle for 15 s at 30 Hz. Diameter was observed using bright field microscopy. In controls, muscle contraction produced a 15.7 ± 1.5 μm dilatation from a baseline of 17.4 ± 1.6 μm. Endothelial denudation (−EC) via intraluminal perfusion of air abolished this response (1.6 ± 1.2 μm in −EC, P < 0.05), identifying endothelium as the primary vascular cell type initiating the dilatation. To investigate the role of EC Ca2+ in metabolic dilatation, arteriolar ECs were loaded with Fluo-4 AM or BAPTA AM by intraluminal perfusion, after which blood flow was re-established. Ca2+ activity of individual ECs was monitored as a function of change from baseline fluorescence using confocal microscopy. In ECs, whole cell Ca2+ increased (>10%, P < 0.05) during muscle contraction, and localized Ca2+ transients were increased (>20%, P < 0.05) during the first minute after contraction. Chelation of EC Ca2+ abolished the dilatations in response to muscle contraction (1.1 ± 0.7 μm, P < 0.05). Inhibition of P1 purinergic receptors (with xanthine amine congener) did not alter the rate of onset of the dilatation (P > 0.05) but decreased its magnitude immediately post stimulation (7.1 ± 0.9 μm, P < 0.05) and during recovery. These findings demonstrate obligatory roles for endothelium and EC Ca2+ during metabolic dilatation in intact arterioles. Furthermore, they suggest that at least two separate pathways mediate the local response, one of which involves stimulation of endothelial P1 purinergic receptors via endogenous adenosine produced during muscle activity. PMID:14694141

  14. Adjustments differ among low-threshold motor units during intermittent, isometric contractions.

    PubMed

    Farina, Dario; Holobar, Ales; Gazzoni, Marco; Zazula, Damjan; Merletti, Roberto; Enoka, Roger M

    2009-01-01

    We investigated the changes in muscle fiber conduction velocity, recruitment and derecruitment thresholds, and discharge rate of low-threshold motor units during a series of ramp contractions. The aim was to compare the adjustments in motor unit activity relative to the duration that each motor unit was active during the task. Multichannel surface electromyographic (EMG) signals were recorded from the abductor pollicis brevis muscle of eight healthy men during 12-s contractions (n = 25) in which the force increased and decreased linearly from 0 to 10% of the maximum. The maximal force exhibited a modest decline (8.5 +/- 9.3%; P < 0.05) at the end of the task. The discharge times of 73 motor units that were active for 16-98% of the time during the first five contractions were identified throughout the task by decomposition of the EMG signals. Action potential conduction velocity decreased during the task by a greater amount for motor units that were initially active for >70% of the time compared with that of less active motor units. Moreover, recruitment and derecruitment thresholds increased for these most active motor units, whereas the thresholds decreased for the less active motor units. Another 18 motor units were recruited at an average of 171 +/- 32 s after the beginning of the task. The recruitment and derecruitment thresholds of these units decreased during the task, but muscle fiber conduction velocity did not change. These results indicate that low-threshold motor units exhibit individual adjustments in muscle fiber conduction velocity and motor neuron activation that depended on the relative duration of activity during intermittent contractions.

  15. AMPKα2 deficiency uncovers time dependency in the regulation of contraction-induced palmitate and glucose uptake in mouse muscle.

    PubMed

    Abbott, Marcia J; Bogachus, Lindsey D; Turcotte, Lorraine P

    2011-07-01

    AMP-activated protein kinase (AMPK) is a fuel sensor in skeletal muscle with multiple downstream signaling targets that may be triggered by increases in intracellular Ca(2+) concentration ([Ca(2+)]). The purpose of this study was to determine whether increases in intracellular [Ca(2+)] induced by caffeine act solely via AMPKα(2) and whether AMPKα(2) is essential to increase glucose uptake, fatty acid (FA) uptake, and FA oxidation in contracting skeletal muscle. Hindlimbs from wild-type (WT) or AMPKα(2) dominant-negative (DN) transgene mice were perfused during rest (n = 11), treatment with 3 mM caffeine (n = 10), or muscle contraction (n = 11). Time-dependent effects on glucose and FA uptake were uncovered throughout the 20-min muscle contraction perfusion period (P < 0.05). Glucose uptake rates did not increase in DN mice during muscle contraction until the last 5 min of the protocol (P < 0.05). FA uptake rates were elevated at the onset of muscle contraction and diminished by the end of the protocol in DN mice (P < 0.05). FA oxidation rates were abolished in the DN mice during muscle contraction (P < 0.05). The DN transgene had no effect on caffeine-induced FA uptake and oxidation (P > 0.05). Glucose uptake rates were blunted in caffeine-treated DN mice (P < 0.05). The DN transgene resulted in a greater use of intramuscular triglycerides as a fuel source during muscle contraction. The DN transgene did not alter caffeine- or contraction-mediated changes in the phosphorylation of Ca(2+)/calmodulin-dependent protein kinase I or ERK1/2 (P > 0.05). These data suggest that AMPKα(2) is involved in the regulation of substrate uptake in a time-dependent manner in contracting muscle but is not necessary for regulation of FA uptake and oxidation during caffeine treatment.

  16. Endogenous Cardiac Troponin T Modulates Ca2+-Mediated Smooth Muscle Contraction

    PubMed Central

    Kajioka, Shunichi; Takahashi-Yanaga, Fumi; Shahab, Nouval; Onimaru, Mitsuho; Matsuda, Miho; Takahashi, Ryosuke; Asano, Haruhiko; Morita, Hiromitsu; Morimoto, Sachio; Yonemitsu, Yoshikazu; Hayashi, Maya; Seki, Narihito; Sasaguri, Toshiuyki; Hirata, Masato; Nakayama, Shinsuke; Naito, Seiji

    2012-01-01

    Mechanisms linked to actin filaments have long been thought to cooperate in smooth muscle contraction, although key molecules were unclear. We show evidence that cardiac troponin T (cTnT) substantially contributes to Ca2+-mediated contraction in a physiological range of cytosolic Ca2+ concentration ([Ca2+]i). cTnT was detected in various smooth muscles of the aorta, trachea, gut and urinary bladder, including in humans. Also, cTnT was distributed along with tropomyosin in smooth muscle cells, suggesting that these proteins are ready to cause smooth muscle contraction. In chemically permeabilised smooth muscle of cTnT+/− mice in which cTnT reduced to ~50%, the Ca2+-force relationship was shifted toward greater [Ca2+]i, indicating a sizeable contribution of cTnT to smooth muscle contraction at [Ca2+]i < 1 μM. Furthermore, addition of supplemental TnI and TnC reconstructed a troponin system to enhance contraction. The results indicated that a Tn/Tn-like system on actin-filaments cooperates together with the thick-filament pathway. PMID:23248744

  17. Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Perreault, C. L.; Shannon, R. P.; Komamura, K.; Vatner, S. F.; Morgan, J. P.

    1992-01-01

    24 d of rapid ventricular pacing induced dilated cardiomyopathy with both systolic and diastolic dysfunction in conscious, chronically instrumented dogs. We studied mechanical properties and intracellular calcium (Ca2+i) transients of trabeculae carneae isolated from 15 control dogs (n = 32) and 11 dogs with pacing-induced cardiac failure (n = 26). Muscles were stretched to maximum length at 30 degrees C and stimulated at 0.33 Hz; a subset (n = 17 control, n = 17 myopathic) was loaded with the [Ca2+]i indicator aequorin. Peak tension was depressed in the myopathic muscles, even in the presence of maximally effective (i.e., 16 mM) [Ca2+] in the perfusate. However, peak [Ca2+]i was similar (0.80 +/- 0.13 vs. 0.71 +/- 0.05 microM; [Ca2+]o = 2.5 mM), suggesting that a decrease in Cai2+ availability was not responsible for the decreased contractility. The time for decline from the peak of the Cai2+ transient was prolonged in the myopathic group, which correlated with prolongation of isometric contraction and relaxation. However, similar end-diastolic [Ca2+]i was achieved in both groups (0.29 +/- 0.05 vs. 0.31 +/- 0.02 microM), indicating that Cai2+ homeostasis can be maintained in myopathic hearts. The inotropic response of the myopathic muscles to milrinone was depressed compared with the controls. However, when cAMP production was stimulated by pretreatment with forskolin, the response of the myopathic muscles to milrinone was improved. Our findings provide direct evidence that abnormal [Ca2+]i handling is an important cause of contractile dysfunction in dogs with pacing-induced heart failure and suggest that deficient production of cAMP may be an important cause of these changes in excitation-contraction coupling.

  18. Alpha List of Prime Contract Awards. Oct 92-Sep 93. FY93. (Greenberg Roofing & Shtmtl Co. - Hst Building Services Inc.). Part 9

    DTIC Science & Technology

    1994-03-01

    r ;[. ;, :, ’,,cM ,,,,qr:•mReports U, ’. NASA Leiv tank r , <iA .- a* ’ ~ ber’ ise t e NTIS Le, e bIank iol C).% nq ; Jb ;0•- C *o c a•.n PR Block 13...000 0 - P, PI r. -. 0 0 <. (4’) I 6 I 00040 UO O On In U) W)uU)Ul 01 000 A60 in))0 390 0 0 0) HH CI 0004DI I, 0 0 ( 4 O0 00) =N 0o00 00) 0 0I If 110040...0 c D-4-4 0.4 0)NNNC C 00 40.4 NNc 0.-i WON 0) 4 W 0() Go 9 00 CL1, 0 0 0 0 0 0 0 0 0 0 0 0.H 100004WH M a zzzz> II II HH 00N11,44400000 I IU l, OO

  19. Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.

    PubMed

    Johansen, P B; Hansen, K T; Andersen, J V; Johansen, N L

    1998-11-01

    1. The pharmacokinetics of three new peptidyl growth hormone secretagogues, ipamorelin (NNC 26-0161), NNC 26-0194 and NNC 26-0235, were compared with two well-known hexapeptides, GHRP-2 and GHRP-6, in the male rat following different routes of administration. 2. Following i.v. bolus injection, plasma concentrations of the peptides declined biexponentially. Ipamorelin differed markedly from the other peptides investigated, demonstrating a systemic plasma clearance 5-fold lower than that of GHRP-6. Ipamorelin was mainly excreted in the urine, whereas GHRP-6 was predominantly excreted in the bile. NNC 26-0194 and NNC 26-0235 also showed high biliary excretions. Ipamorelin and the two NNC peptides were moderately resistant towards metabolism as 60-80% of the administered dose could be recovered from bile and urine as intact peptide. 3. After intranasal application, the bioavailability of ipamorelin was estimated at approximately 20%. Higher bioavailabilities of approximately 50% were determined for NNC 26-0235, NNC 26-0194 and GHRP-2, whereas the nasal absorption of GHRP-6 was somewhat lower. Thus, the peptides could be easily transported across the nasal epithelium suggesting that the nasal route seems promising for systemic delivery of this family of peptidyl growth hormone secretagogues.

  20. Calcium influx through L-type channels attenuates skeletal muscle contraction via inhibition of adenylyl cyclases.

    PubMed

    Menezes-Rodrigues, Francisco Sandro; Pires-Oliveira, Marcelo; Duarte, Thiago; Paredes-Gamero, Edgar Julian; Chiavegatti, Tiago; Godinho, Rosely Oliveira

    2013-11-15

    Skeletal muscle contraction is triggered by acetylcholine induced release of Ca(2+) from sarcoplasmic reticulum. Although this signaling pathway is independent of extracellular Ca(2+), L-type voltage-gated calcium channel (Cav) blockers have inotropic effects on frog skeletal muscles which occur by an unknown mechanism. Taking into account that skeletal muscle fiber expresses Ca(+2)-sensitive adenylyl cyclase (AC) isoforms and that cAMP is able to increase skeletal muscle contraction force, we investigated the role of Ca(2+) influx on mouse skeletal muscle contraction and the putative crosstalk between extracellular Ca(2+) and intracellular cAMP signaling pathways. The effects of Cav blockers (verapamil and nifedipine) and extracellular Ca(2+) chelator EGTA were evaluated on isometric contractility of mouse diaphragm muscle under direct electrical stimulus (supramaximal voltage, 2 ms, 0.1 Hz). Production of cAMP was evaluated by radiometric assay while Ca(2+) transients were assessed by confocal microscopy using L6 cells loaded with fluo-4/AM. Ca(2+) channel blockers verapamil and nifedipine had positive inotropic effect, which was mimicked by removal of extracellular Ca(+2) with EGTA or Ca(2+)-free Tyrode. While phosphodiesterase inhibitor IBMX potentiates verapamil positive inotropic effect, it was abolished by AC inhibitors SQ22536 and NYK80. Finally, the inotropic effect of verapamil was associated with increased intracellular cAMP content and mobilization of intracellular Ca(2+), indicating that positive inotropic effects of Ca(2+) blockers depend on cAMP formation. Together, our results show that extracellular Ca(2+) modulates skeletal muscle contraction, through inhibition of Ca(2+)-sensitive AC. The cross-talk between extracellular calcium and cAMP-dependent signaling pathways appears to regulate the extent of skeletal muscle contraction responses. © 2013 Published by Elsevier B.V.

  1. 48 CFR 237.170-2 - Approval requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-2 Approval requirements. (a) Acquisition of services through a contract or task order that is not performance based. (1) For acquisitions at or below $85.5 million, obtain the approval of the official... the senior procurement executive. (b) Acquisition of services through use of a contract or task order...

  2. Fact Book 2012

    DTIC Science & Technology

    2012-01-01

    CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ...ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School,1 University Circle,Monterey,CA,93943 8. PERFORMING ORGANIZATION REPORT NUMBER 9...while building the intellectual capital of the Naval Postgraduate School faculty. Naval Postgraduate School Vision NPS develops creative

  3. Ca2+-pumping impairment during repetitive fatiguing contractions in single myofibers: role of cross-bridge cycling

    PubMed Central

    Shiah, Amy A.; Gandra, Paulo G.; Hogan, Michael C.

    2013-01-01

    The energy cost of contractions in skeletal muscle involves activation of both actomyosin and sarcoplasmic reticulum (SR) Ca2+-pump (SERCA) ATPases, which together determine the overall ATP demand. During repetitive contractions leading to fatigue, the relaxation rate and Ca2+ pumping become slowed, possibly because of intracellular metabolite accumulation. The role of the energy cost of cross-bridge cycling during contractile activity on Ca2+-pumping properties has not been investigated. Therefore, we inhibited cross-bridge cycling by incubating isolated Xenopus single fibers with N-benzyl-p-toluene sulfonamide (BTS) to study the mechanisms by which SR Ca2+ pumping is impaired during fatiguing contractions. Fibers were stimulated in the absence (control) and presence of BTS and cytosolic calcium ([Ca2+]c) transients or intracellular pH (pHi) changes were measured. BTS treatment allowed normal [Ca2+]c transients during stimulation without cross-bridge activation. At the time point that tension was reduced to 50% in the control condition, the fall in the peak [Ca2+]c and the increase in basal [Ca2+]c did not occur with BTS incubation. The progressively slower Ca2+ pumping rate and the fall in pHi during repetitive contractions were reduced during BTS conditions. However, when mitochondrial ATP supply was blocked during contractions with BTS present (BTS + cyanide), there was no further slowing in SR Ca2+ pumping during contractions compared with the BTS-alone condition. Furthermore, the fall in pHi was significantly less during the BTS + cyanide condition than in the control conditions. These results demonstrate that factors related to the energetic cost of cross-bridge cycling, possibly the accumulation of metabolites, inhibit the Ca2+ pumping rate during fatiguing contractions. PMID:23678027

  4. Somatostatin receptor subtype-4 agonist NNC 26-9100 decreases extracellular and intracellular Aβ₁₋₄₂ trimers.

    PubMed

    Sandoval, Karin E; Farr, Susan A; Banks, William A; Crider, Albert M; Morley, John E; Witt, Ken A

    2012-05-15

    Soluble amyloid β-protein (Aβ) oligomers are primary mediators of synaptic dysfunction associated with the progression of Alzheimer's disease. Such Aβ oligomers exist dependent on their rates of aggregation and metabolism. Use of selective somatostatin receptor-subtype agonists have been identified as a potential means to mitigate Aβ accumulation in the brain, via regulation of the enzyme neprilysin. Herein, we first evaluated the impact of the somatostatin receptor subtype-4 agonist 1-[3-[N-(5-Bromopyridin-2-yl)-N-(3,4-dichlorobenzyl)amino]propyl]-3-[3-(1H-imidazol-4-yl)propyl]thiourea (NNC 26-9100) on learning and memory in 12-month SAMP8 mice (i.c.v. injection). NNC 26-9100 (0.2 μg-dose) was shown to enhance both learning (T-maze) and memory (object recognition) compared to vehicle controls. Cortical and hippocampal tissues were evaluated subsequent to NNC 26-9100 (0.2 μg) or vehicle administration for changes in neprilysin activity, along with protein expression of amyloid-precursor protein (APP), neprilysin, and Aβ₁₋₄₂ oligomers within respective cellular fractions (extracellular, intracellular and membrane). NNC 26-9100 increased neprilysin activity in cortical tissue, with an associated protein expression increase in the extracellular fraction and decreased in the intracellular fraction. A decrease in intracellular APP expression was found with treatment in both cortical and hippocampal tissues. NNC 26-9100 also significantly decreased expression of Aβ₁₋₄₂ trimers within both the extracellular and intracellular cortical fractions. No expression changes were found in membrane fractions for any protein. These finding suggest the potential use of selective SSTR4 agonists to mitigate toxic oligomeric forms of Aβ₁₋₄₂ in critical regions of the brain identified with learning and memory decline. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Mechanisms underlying the relaxant effect of Galetin 3,6- dimethyl ether, from Piptadenia stipulacea (Benth.) Ducke, on guinea-pig trachea.

    PubMed

    Macêdo, Cibério Landim; Vasconcelos, Luiz Henrique César; Correia, Ana Carolina de Carvalho; Martins, Italo Rossi Roseno; Lira, Daysianne Pereira de; Santos, Bárbara Viviana de Oliveira; Silva, Bagnólia Araújo da

    2014-01-01

    Galetin 3,6-dimethyl ether (FGAL), a flavonoid from the aerial parts of Piptadenia stipulacea (Benth.) Ducke, was found to exert a relaxant effect on carbachol (CCh)-pre-contracted guinea-pig trachea. Based on cumulative concentration-response curves to CCh, FGAL antagonized muscarinic receptors pseudo-irreversibly and noncompetitively, since it inhibited and shifted these curves towards higher concentrations in a nonparallel manner. In addition, FGAL was more potent in relaxing contractions induced by 18 mM as compared to 60 mM KCl (pD2 = 5:50 ±0:36 and 4.80 ±0.07, respectively), indicating the participation of K+ channels. In the presence of 10 mM tetraethylammonium (TEA+) chloride, a nonselective K+ channel blocker, the relaxant potency of FGAL was reduced (from pD2 = 5:12 ±0:07 to 4.87 ±0.02). Among several selective blockers of K+ channel subtypes, only apamin, an SKCa (small-conductance Ca2+-activated K+ channels) blocker, attenuated the relaxant potency of FGAL (pD2 = 4:85±0:06), suggesting SKCa activation. FGAL was equipotent in relaxing trachea contracted by 60 mM KCl (pD2 =4:80 ±0:07) or 10-6 M CCh (pD2 = 5:02 ±0:07), suggesting CaV (voltage-gated calcium channel), but not ROCs (receptor-operated calcium channels) participation. Furthermore, aminophylline-induced relaxation (pD2 = 4:12 ±0:06) was potentiated around 4-fold (pD2 = 4:80 ±0:44) in the presence of FGAL. Moreover, forskolininduced relaxation (pD2 = 6:51 ±0:06) was potentiated around 2.5-fold (pD2 = 6:90 ±0:05) by FGAL. Conversely, sodium nitroprusside-induced relaxation was unaffected, indicating that the AC/cAMP/PKA pathway, but not the NO pathway, may be modulated by the flavonoid. These results suggest that, in guinea-pig trachea, FGAL induces relaxation by pseudo-irreversible noncompetitive antagonism on muscarinic receptors, modulation of K+ and Ca2+ channels, as well as activation of the AC/cAMP/PKA pathway.

  6. Access Point Selection for Multi-Rate IEEE 802.11 Wireless LANs

    DTIC Science & Technology

    2014-05-16

    Mobile Systems, Applications and Services, 2006. [2] S . Vasudevan, K. Papagiannaki, C . Diot, J. Kurose, and D. Towsley, “Facilitating Access Point...LANs 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) University of California at Berkeley,Electrical Engineering and Computer Sciences,Berkeley,CA,94720 8

  7. In vivo Ca2+ buffering capacity and microvascular oxygen pressures following muscle contractions in diabetic rat skeletal muscles: fiber-type specific effects.

    PubMed

    Eshima, Hiroaki; Poole, David C; Kano, Yutaka

    2015-07-15

    In Type 1 diabetes, skeletal muscle resting intracellular Ca(2+) concentration ([Ca(2+)]i) homeostasis is impaired following muscle contractions. It is unclear to what degree this behavior is contingent upon fiber type and muscle oxygenation conditions. We tested the hypotheses that: 1) the rise in resting [Ca(2+)]i evident in diabetic rat slow-twitch (type I) muscle would be exacerbated in fast-twitch (type II) muscle following contraction; and 2) these elevated [Ca(2+)]i levels would relate to derangement of microvascular partial pressure of oxygen (PmvO2 ) rather than sarcoplasmic reticulum dysfunction per se. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (CONT) groups. Four weeks later extensor digitorum longus (EDL, predominately type II fibers) and soleus (SOL, predominately type I fibers) muscle contractions were elicited by continuous electrical stimulation (120 s, 100 Hz). Ca(2+) imaging was achieved using fura 2-AM in vivo (i.e., circulation intact). DIA increased fatigability in EDL (P < 0.05) but not SOL. In recovery, SOL [Ca(2+)]i either returned to its resting baseline within 150 s (CONT 1.00 ± 0.02 at 600 s) or was not elevated in recovery at all (DIA 1.03 ± 0.02 at 600 s, P > 0.05). In recovery, EDL CONT [Ca(2+)]i also decreased to values not different from baseline (1.06 ± 0.01, P > 0.05) at 600 s. In marked contrast, EDL DIA [Ca(2+)]i remained elevated for the entire recovery period (i.e., 1.23 ± 0.03 at 600 s, P < 0.05). The inability of [Ca(2+)]i to return to baseline in EDL DIA was not associated with any reduction of SR Ca(2+)-ATPase (SERCA) 1 or SERCA2 protein levels (both increased 30-40%, P < 0.05). However, Pmv(O2) recovery kinetics were markedly slowed in EDL such that mean Pmv(O2) was substantially depressed (CONT 27.9 ± 2.0 vs. DIA 18.4 ± 2.0 Torr, P < 0.05), and this behavior was associated with the elevated [Ca(2+)]i. In contrast, this was not the case for SOL (P > 0.05) in that neither [Ca(2+)]i nor Pmv(O2) were deranged in recovery with DIA. In conclusion, recovery of [Ca(2+)]i homeostasis is impaired in diabetic rat fast-twitch but not slow-twitch muscle in concert with reduced Pmv(O2) pressures. Copyright © 2015 the American Physiological Society.

  8. Development of Powder Processing Models and Techniques for Meso-scale Devices: Perspirable Skin

    DTIC Science & Technology

    2008-03-31

    of Powder Processing Models and Techniques for Meso-scale Devices: Perspirable Skin Contract Number ...Skin 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-05-1-0202 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Patrick Kwon, Michigan State University 5d...PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Patrick Kwon Department of

  9. Voltage-dependent Ca2+ release from the SR of feline ventricular myocytes is explained by Ca2+-induced Ca2+ release.

    PubMed

    Piacentino, V; Dipla, K; Gaughan, J P; Houser, S R

    2000-03-15

    1. Direct voltage-gated (voltage-dependent Ca2+ release, VDCR) and Ca2+ influx-gated (Ca2+-induced Ca2+ release, CICR) sarcoplasmic reticulum (SR) Ca2+ release were studied in feline ventricular myocytes. The voltage-contraction relationship predicted by the VDCR hypothesis is sigmoidal with large contractions at potentials near the Ca2+ equilibrium potential (ECa). The relationship predicted by the CICR hypothesis is bell-shaped with no contraction at ECa. 2. The voltage dependence of contraction was measured in ventricular myocytes at physiological temperature (37 C), resting membrane potential and physiological [K+]. Experiments were performed with cyclic adenosine 3',5'-monophosphate (cAMP) in the pipette or in the presence of the beta-adrenergic agonist isoproterenol (isoprenaline; ISO). 3. The voltage-contraction relationship was bell-shaped in Na+-free solutions (to eliminate the Na+ current and Na+-Ca2+ exchange, NCX) but the relationship was broader than the L-type Ca2+ current (ICa,L)-voltage relationship. 4. Contractions induced with voltage steps from normal resting potentials to -40 mV are thought to represent VDCR rather than CICR. We found that cAMP and ISO shifted the voltage dependence of ICa,L activation to more negative potentials so that ICa,L was always present with steps to -40 mV. ICa,L at -40 mV inactivated when the holding potential was decreased (VŁ = -57.8 +/- 0.49 mV). 5. ISO increased inward current, SR Ca2+ load and contraction in physiological [Na+] and a broad bell-shaped voltage-contraction relationship was observed. Inhibition of reverse-mode NCX, decreasing ICa,L and decreasing SR Ca2+ loading all decreased contractions at strongly positive potentials near ECa. 6. The voltage-contraction relationship in 200 microM cadmium (Cd2+) was bell-shaped, supporting a role of ICa,L rather than VDCR. 7. All results could be accounted for by the CICR hypothesis, and many results exclude the VDCR hypothesis.

  10. Generating Lookup Tables from the AE9/AP9 Models

    DTIC Science & Technology

    2015-06-16

    AP9 Models 5a. CONTRACT NUMBER FA8802-14-C-0001 5b. GRANT NUMBER na 5c. PROGRAM ELEMENT NUMBER 5811 6. AUTHOR( S ) Joshua P. Davis 5d. PROJECT...NUMBER 11 5e. TASK NUMBER na 5f. WORK UNIT NUMBER na 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) The Aerospace Corporation 2310 E. El...Segundo Blvd. El Segundo, CA 90245-4609 8. PERFORMING ORGANIZATION REPORT NUMBER TOR-2015-00893 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS

  11. Influence of carbonate ion in the crystallization medium on the formation and chemical composition of CaHA-SrHA solid solutions

    NASA Astrophysics Data System (ADS)

    Nikolaev, Anton; Kuz'mina, Maria; Frank-Kamenetskaya, Olga; Zorina, Maina

    2015-06-01

    The study of the influence of carbonate ions in a solution to Sr-distribution in system «solution-crystal» and to ion substitutions and the non-stoichiometry of formed CaHA-SrHA solid solutions was carried out. The CaHA-SrHA solid solutions were synthesized by precipitation from aqueous solutions with the atomic C/P ratio equal to 0, 0.05 and 0.1 at T = 90 °C. Resulting precipitates were studied using various methods including X-ray powder diffraction, infrared spectroscopy and different chemical analyses. The results of the study have shown that in the range of values of (Ca + Sr)/P in the water solution from 40% to 85%, the presence of carbonate ions (C/P = 0.05-0.1) promotes the incorporation of strontium in the apatite. Crystalline apatite solid solutions formed from water solutions of such composition are more defective compared to apatites that are mainly calcium or strontium. They are characterized by a smaller size coherence scattering domain length along [0 0 1] direction and a greater number of carbonate ions, water molecules and vacancies at the Ca-sites.

  12. Rats socially-reared and full fed learned an autoshaping task, showing less levels of fear-like behaviour than fasted or singly-reared rats.

    PubMed

    Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia

    2004-07-01

    During the learning of instrumental tasks, rats are usually fasted to increase reinforced learning. However, fasting produces several undesirable side effects. The aim of this study was to test the hypothesis that control rats, i.e. full-fed and group-reared rats, will learn an autoshaping task to the same level as fasted or singly-reared rats. The interaction between fasting and single-rearing of rats was also tested. Results showed that control rats and fasted rats acquired the autoshaping task similarly, independently of rearing condition or gender. However, fasted or singly-reared rats produced fear-like behaviour, since male rats group-reared and fasted (85% body/wt, P <0.05), male rats singly-reared (full fed, P <0.05; 12 h fasted, P <0.05; 85% body/wt, P <0.05), female rats group-reared (12 h fasted, P <0.05; 85% body/wt, P <0.05) and female rats singly reared (full fed, P <0.05; 12 h fasted, P <0.05; 85% body/wt, P <0.05) displayed reduced amounts of time exploring the open arms of the elevated plus-maze. In conclusion, control rats learned the autoshaping task to the same level as fasted or singly-reared rats. However, fasting or single-rearing produced fear-like behaviour. Thus, the training of control rats in autoshaping tasks may be an option that improves animal welfare.

  13. Ca²⁺-pumping impairment during repetitive fatiguing contractions in single myofibers: role of cross-bridge cycling.

    PubMed

    Nogueira, Leonardo; Shiah, Amy A; Gandra, Paulo G; Hogan, Michael C

    2013-07-15

    The energy cost of contractions in skeletal muscle involves activation of both actomyosin and sarcoplasmic reticulum (SR) Ca²⁺-pump (SERCA) ATPases, which together determine the overall ATP demand. During repetitive contractions leading to fatigue, the relaxation rate and Ca²⁺ pumping become slowed, possibly because of intracellular metabolite accumulation. The role of the energy cost of cross-bridge cycling during contractile activity on Ca²⁺-pumping properties has not been investigated. Therefore, we inhibited cross-bridge cycling by incubating isolated Xenopus single fibers with N-benzyl-p-toluene sulfonamide (BTS) to study the mechanisms by which SR Ca²⁺ pumping is impaired during fatiguing contractions. Fibers were stimulated in the absence (control) and presence of BTS and cytosolic calcium ([Ca²⁺]c) transients or intracellular pH (pHi) changes were measured. BTS treatment allowed normal [Ca²⁺]c transients during stimulation without cross-bridge activation. At the time point that tension was reduced to 50% in the control condition, the fall in the peak [Ca²⁺]c and the increase in basal [Ca²⁺]c did not occur with BTS incubation. The progressively slower Ca²⁺ pumping rate and the fall in pHi during repetitive contractions were reduced during BTS conditions. However, when mitochondrial ATP supply was blocked during contractions with BTS present (BTS + cyanide), there was no further slowing in SR Ca²⁺ pumping during contractions compared with the BTS-alone condition. Furthermore, the fall in pHi was significantly less during the BTS + cyanide condition than in the control conditions. These results demonstrate that factors related to the energetic cost of cross-bridge cycling, possibly the accumulation of metabolites, inhibit the Ca²⁺ pumping rate during fatiguing contractions.

  14. Comparison of mibefradil and derivative NNC 55-0396 effects on behavior, cytochrome P450 activity, and tremor in mouse models of essential tremor

    PubMed Central

    Quesada, Arnulfo; Bui, Peter H.; Homanics, Gregg E.; Hankinson, Oliver; Handforth, Adrian

    2014-01-01

    NNC 55-0396 [(1S,2S)-2-(2-(N-[(3-benzimidazol-2-yl)propyl]-N-methylamino)ethyl)-6-fluoro-1,2, 3,4-tetrahydro-1-isopropyl-2-naphtyl cyclopropanecarboxylate dihydrochloride], is a mibefradil derivative that retains potent in vitro T-type calcium channel antagonist efficacy. We compared the two compounds for behavioral toxicity, effects on cytochrome P450 activity, and efficacy against tremor in the γ-aminobutyric acid type A (GABAA) receptor subunit α1-null mouse, and the harmaline tremor model of essential tremor in wild-type mice. NNC 55-0396 was better tolerated than mibefradil in the horizontal wire test of sedation/motor function, with 3/6 failing at 300 and 30 mg/kg respectively. To assess for a potential interaction with harmaline, mice were given the drugs, followed by harmaline or vehicle, and tested 30 min later in the inverted wire grid test. Mibefradil exacerbated, whereas NNC 55-0396 ameliorated harmaline-induced test deficits. In mouse liver microsomes, NNC 55-0396 was a less potent inhibitor of harmaline O-demethylation than mibefradil (Ki: 0.95 and 0.29 µM respectively), and also less potent at inhibiting testosterone 6-β-hydroxylation (Ki: 0.71 and 0.12 µM respectively). In the GABAA α1-null model, NNC 55-0396 but not mibefradil, (each at 20 mg/kg), suppressed tremor while NNC 55-0396 at 12.5 mg/kg suppressed harmaline-induced tremor by half by 20–100 min, whereas mibefradil at the same dose did not significantly affect tremor. In contrast to mibefradil, NNC 55-0396 is well tolerated and suppresses tremor, and exerts less cytochrome P450 inhibition. These results suggest potential clinical utility for NNC 55-0396 or similar derivatives as a T-type calcium antagonist. PMID:21256842

  15. Defense Small Business Innovation Research Program (SBIR). Defense Agencies Abstracts of Phase 2 Awards 1993

    DTIC Science & Technology

    1993-01-01

    to seven transmitters operating in the 1.71-1.85 and 2.2-2.3 GHz telemetry bands can simultaneously be connected to this antenna without interference ...HUNTINGTON BEACH, CA 92649 Contract#N: DAAA21-91-C-0034 Phone: (714) 373-5509 PI: Dr. Timothy M. Rynne Tide: Electromagnetic Interference (EMI)/Electro...y position data. The system is designed to counteract the severe multipath interference environment resulting from operation within a metal building

  16. Research in Supercritical Fuel Properties and Combustion Modeling

    DTIC Science & Technology

    2015-09-18

    AFRL-AFOSR-VA-TR-2015-0296 RESEARCH IN SUPERCRITICAL FUEL PROPERTIES AND COMBUSTION MODELING Gregory Faris SRI INTERNATIONAL MENLO PARK CA Final...Properties and Combustion Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0177 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Gregory W...carbon atom species for combustion modeling and optimization. On the stimulated scattering task, we have tested new methods for rapidly scanning

  17. The L‐type Ca2+ channel facilitates abnormal metabolic activity in the cTnI‐G203S mouse model of hypertrophic cardiomyopathy

    PubMed Central

    Viola, Helena; Johnstone, Victoria; Cserne Szappanos, Henrietta; Richman, Tara; Tsoutsman, Tatiana; Filipovska, Aleksandra; Semsarian, Christopher

    2016-01-01

    Key points Genetic mutations in cardiac troponin I (cTnI) are associated with development of hypertrophic cardiomyopathy characterized by myocyte remodelling, disorganization of cytoskeletal proteins and altered energy metabolism.The L‐type Ca2+ channel is the main route for calcium influx and is crucial to cardiac excitation and contraction. The channel also regulates mitochondrial function in the heart by a functional communication between the channel and mitochondria via the cytoskeletal network.We find that L‐type Ca2+ channel kinetics are altered in cTnI‐G203S cardiac myocytes and that activation of the channel causes a significantly greater increase in mitochondrial membrane potential and metabolic activity in cTnI‐G203S cardiac myocytes.These responses occur as a result of impaired communication between the L‐type Ca2+ channel and cytoskeletal protein F‐actin, involving decreased movement of actin–myosin and block of the mitochondrial voltage‐dependent anion channel, resulting in a ‘hypermetabolic’ mitochondrial state.We propose that L‐type Ca2+ channel antagonists, such as diltiazem, might be effective in reducing the cardiomyopathy by normalizing mitochondrial metabolic activity. Abstract Genetic mutations in cardiac troponin I (cTnI) account for 5% of families with hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is associated with disorganization of cytoskeletal proteins and altered energy metabolism. The L‐type Ca2+ channel (ICa‐L) plays an important role in regulating mitochondrial function. This involves a functional communication between the channel and mitochondria via the cytoskeletal network. We investigate the role of ICa‐L in regulating mitochondrial function in 25‐ to 30‐week‐old cardiomyopathic mice expressing the human disease‐causing mutation Gly203Ser in cTnI (cTnI‐G203S). The inactivation rate of ICa‐L is significantly faster in cTnI‐G203S myocytes [cTnI‐G203S: τ1 = 40.68 ± 3.22, n = 10 vs. wild‐type (wt): τ1 = 59.05 ± 6.40, n = 6, P < 0.05]. Activation of ICa‐L caused a greater increase in mitochondrial membrane potential (Ψm, 29.19 ± 1.85%, n = 15 vs. wt: 18.84 ± 2.01%, n = 10, P < 0.05) and metabolic activity (24.40 ± 6.46%, n = 8 vs. wt: 9.98 ± 1.57%, n = 9, P < 0.05). The responses occurred because of impaired communication between ICa‐L and F‐actin, involving lack of dynamic movement of actin–myosin and block of the mitochondrial voltage‐dependent anion channel. Similar responses were observed in precardiomyopathic mice. ICa‐L antagonists nisoldipine and diltiazem decreased Ψm to basal levels. We conclude that the Gly203Ser mutation leads to impaired functional communication between ICa‐L and mitochondria, resulting in a ‘hypermetabolic’ state. This might contribute to development of cTnI‐G203S cardiomyopathy because the response is present in young precardiomyopathic mice. ICa‐L antagonists might be effective in reducing the cardiomyopathy by altering mitochondrial function. PMID:27062056

  18. Lanthanide Contraction Effect In Magnetic Thermoelectric Materials Of Rare Earth-doped Bi1.5Pb0.5Ca2Co2O8

    NASA Astrophysics Data System (ADS)

    Sutjahja, Inge Magdalena; Akbar, Taufik; Nugroho, Agung

    2010-12-01

    We report in this paper the result of synthesis and crystal structure characterization of magnetic thermoelectric materials of rare-earth-doped Bi1.5Pb0.5Ca2Co2O8, namely Bi1.5Pb0.5Ca1.9RE0.1Co2O8 (RE = La, Pr, Sm, Eu, Gd, Ho). Single phase samples have been prepared by solid state reaction process using precursors of Bi2O3, PbO, CaCO3, RE2O3, and Co3O4. The precursors were pulverized, calcinated, and sintered in air at various temperatures for several hours. Analysis of XRD data shows that Bi1.5Pb0.5Ca1.9RE0.1Co2O8 compound is a layered system consisting of an alternate stack of CoO2 layer and Bi2Sr2O4 block along the c-axis. The misfit structure along b-direction is revealed from the difference of the b-axis length belonging to two sublattices, namely hexagonal CdI2-type CoO2 layer and rock-salt (RS) NaCl-type Bi2Sr2O4 block, while they possess the common a- and c-axis lattice parameters and β angles. The overall crystal structure parameters (a, b, and c) increases with type of doping from La to Ho, namely by decreasing the ionic radii of rare-earth ion. We discuss this phenomenon in terms of the lanthanide contraction, an effect commonly found in the rare-earth compound, results from poor shielding of nuclear charge by 4f electrons. In addition, the values of b-lattice parameters in these rare-earth doped samples are almost the same with those belongs to undoped parent compound (Bi1.5Pb0.5Sr2Co2O8) and its related Y-doped (Bi1.5Pb0.5Ca1.9Y0.1Co2O8) samples, while the c-values reduced significantly in rare-earth doped samples, with opposite trend with those of variation of a-axis length. Morevover, the misfit degree in rare-earth doped compound is higher in compared to parent compound and Y-doped samples. We argue that these structural changes induced by rare-earth doping may provide information for the variation of electronic structure of Co-ions (Co3+ and Co4+), in particular their different spin states of low-spin, intermediate-spin, and high-spin. This, in turn, will affect the thermoelectric properties (Seebeck coefficient) of the system.

  19. Deep neural network convolution (NNC) for three-class classification of diffuse lung disease opacities in high-resolution CT (HRCT): consolidation, ground-glass opacity (GGO), and normal opacity

    NASA Astrophysics Data System (ADS)

    Hashimoto, Noriaki; Suzuki, Kenji; Liu, Junchi; Hirano, Yasushi; MacMahon, Heber; Kido, Shoji

    2018-02-01

    Consolidation and ground-glass opacity (GGO) are two major types of opacities associated with diffuse lung diseases. Accurate detection and classification of such opacities are crucially important in the diagnosis of lung diseases, but the process is subjective, and suffers from interobserver variability. Our study purpose was to develop a deep neural network convolution (NNC) system for distinguishing among consolidation, GGO, and normal lung tissue in high-resolution CT (HRCT). We developed ensemble of two deep NNC models, each of which was composed of neural network regression (NNR) with an input layer, a convolution layer, a fully-connected hidden layer, and a fully-connected output layer followed by a thresholding layer. The output layer of each NNC provided a map for the likelihood of being each corresponding lung opacity of interest. The two NNC models in the ensemble were connected in a class-selection layer. We trained our NNC ensemble with pairs of input 2D axial slices and "teaching" probability maps for the corresponding lung opacity, which were obtained by combining three radiologists' annotations. We randomly selected 10 and 40 slices from HRCT scans of 172 patients for each class as a training and test set, respectively. Our NNC ensemble achieved an area under the receiver-operating-characteristic (ROC) curve (AUC) of 0.981 and 0.958 in distinction of consolidation and GGO, respectively, from normal opacity, yielding a classification accuracy of 93.3% among 3 classes. Thus, our deep-NNC-based system for classifying diffuse lung diseases achieved high accuracies for classification of consolidation, GGO, and normal opacity.

  20. Voltage-dependent Ca2+ release from the SR of feline ventricular myocytes is explained by Ca2+-induced Ca2+ release

    PubMed Central

    Piacentino, Valentino; Dipla, Konstantina; Gaughan, John P; Houser, Steven R

    2000-01-01

    Direct voltage-gated (voltage-dependent Ca2+ release, VDCR) and Ca2+ influx-gated (Ca2+-induced Ca2+ release, CICR) sarcoplasmic reticulum (SR) Ca2+ release were studied in feline ventricular myocytes. The voltage-contraction relationship predicted by the VDCR hypothesis is sigmoidal with large contractions at potentials near the Ca2+ equilibrium potential (ECa). The relationship predicted by the CICR hypothesis is bell-shaped with no contraction at ECa. The voltage dependence of contraction was measured in ventricular myocytes at physiological temperature (37 °C), resting membrane potential and physiological [K+]. Experiments were performed with cyclic adenosine 3′,5′-monophosphate (cAMP) in the pipette or in the presence of the β-adrenergic agonist isoproterenol (isoprenaline; ISO). The voltage-contraction relationship was bell-shaped in Na+-free solutions (to eliminate the Na+ current and Na+-Ca2+ exchange, NCX) but the relationship was broader than the L-type Ca2+ current (ICa,L)-voltage relationship. Contractions induced with voltage steps from normal resting potentials to -40 mV are thought to represent VDCR rather than CICR. We found that cAMP and ISO shifted the voltage dependence of ICa,L activation to more negative potentials so that ICa,L was always present with steps to -40 mV. ICa,L at -40 mV inactivated when the holding potential was decreased (V½ =−57·8 ± 0·49 mV). ISO increased inward current, SR Ca2+ load and contraction in physiological [Na+] and a broad bell-shaped voltage-contraction relationship was observed. Inhibition of reverse-mode NCX, decreasing ICa,L and decreasing SR Ca2+ loading all decreased contractions at strongly positive potentials near ECa. The voltage-contraction relationship in 200 μM cadmium (Cd2+) was bell-shaped, supporting a role of ICa,L rather than VDCR. All results could be accounted for by the CICR hypothesis, and many results exclude the VDCR hypothesis. PMID:10718736

  1. Dollar Summary of Prime Contract Awards by Contractor, State or Country, and Place, FY 85. Part 5 (Seaward Construction - Zytron Corporation).

    DTIC Science & Technology

    1985-01-01

    4𔃺 00 1.C~ f6 Ln N a do00 0 wa n a L 00 43n 0) -ci e4 N1 C14 00 a ~. OD.4 , c I LL. z :i% -4- j i - 0) r -- - 0 I 0 0 00 N oc 0)) co 0)01 00 0 0 ~ J...0 1 1. F6 O. II -F- . I- I .- I I. .C. . . . . . . . . "A6%4 % UU- W4 w CL8 8:0 I 4 I Wt C V 08 I 8 I I e Cl dc m I ) I I Coc (D 0 C nI 4 ( a (4t 4...tLI 0 Z am a - o -4 I I,- - a4 C 0 C-4- acca a O-c 0)( C -. Na( an1 c . -.4 N. Nm ca ’. -. %--ca4-4 0 - a E I Ua an .0- 4 C r- Na C)G I-0C 0 0 0’ 0 ) 0

  2. Velocity of sarcomere shortening in rat cardiac muscle: relationship to force, sarcomere length, calcium and time.

    PubMed

    Daniels, M; Noble, M I; ter Keurs, H E; Wohlfart, B

    1984-10-01

    The relation between force and velocity was determined in sixteen trabeculae of rat right ventricle as a function of time during a twitch, of sarcomere length and of external Ca2+ concentration, [Ca2+]o. The trabeculae were studied in modified Krebs-Henseleit solution at 25 degrees C. Force was measured with a semiconductor strain gauge. Sarcomere length was measured with a laser diffraction system. A servomotor system was used in which control could be switched between sarcomere length, muscle length and force. Force-velocity relations were derived from load clamps and from contractions in which sarcomere length was initially held constant followed by a quick release and slower release of the sarcomeres at controlled velocity. Force-velocity relations were fitted by Hill's equation (Hill, 1938), (Po-P) b = (P+a) V, where P = force, V = velocity, Po = isometric force in mN/mm2 and a and b are constants. For [Ca2+]o = 2.5 mM, with both interventions the values (mean +/- S.D.) were: b = 1.00 +/- 0.45 micron/s; a = 9.52 +/- 5.60 mN/mm2; Vo measured = 13.6 +/- 3.0 micron/s; Vo calculated = 13.4 +/- 3.4 micron/s; Po measured = 96.5 +/- 25.0 mN/mm2; Po calculated = 119.3 +/- 34.5 mN/mm2. Vo rose with [Ca2+]o to a maximum at [Ca2+]o = 1.2 mM when Po was about 50% of maximum, while Po rose with [Ca2+]o to a maximum at above 2.5 mM. Vo rose with time during the twitch to a maximum at 25 ms following onset of contraction; Po was then about 50% of the maximum that was obtained at 120 ms. Vo increased with sarcomere length from zero at a sarcomere length of 1.6 micron to a maximum at 1.85 micron. Between 1.85 micron and 2.3 micron, Vo was constant. At 1.85 micron, Po was about 60% of maximum Po. These results are compatible with the hypothesis that Vo is more sensitive than Po to the amount of Ca2+ bound to the contractile proteins, and that Vo reaches a maximal value with an amount of Ca2+ bound to the contractile proteins at which Po has obtained only about 50% of its maximal value.

  3. Comparison of sarcoplasmic reticulum capabilities in toadfish (Opsanus tau) sonic muscle and rat fast twitch muscle.

    PubMed

    Feher, J J; Waybright, T D; Fine, M L

    1998-08-01

    The sonic muscle of the oyster toadfish, Opsanus tau, can produce unfused contractions at 300 Hz. Electron microscopy shows a great abundance of the Sarcoplasmic reticulum (SR) in this muscle, but no functional characterization of the capabilities of the SR has been reported. We measured the oxalate-supported Ca2+ uptake rate and capacities of homogenates of toadfish sonic muscle and rat extensor digitorum longus (EDL) muscle, and estimated the number of pump units by titration with thapsigargin, a high-affinity, specific inhibitor of the SR Ca-ATPase. The Ca2+ uptake rate averaged 70.9 +/- 9.5 mumol min -1 per g tissue for the toad fish sonic muscle, and 73.5 +/- 3.7 mumol min -1 g-1 for rat EDL. The capacity for Ca2+ -oxalate uptake was 161 +/- 20 mumol g -1 and 33 +/- 2 mumol g -1 for toadfish sonic muscle and rat EDL, respectively. Thus, the rates of Ca2+ uptake were similar in the two muscles, but the toadfish sonic muscle had about five times the capacity of the rat EDL. The number of pumps as estimated by thapsigargin titration was 68 +/- 4 nmol of Ca-ATPase per g tissue in the toadfish, and 42 +/- 5 nmol Ca-ATPase per g tissue in the rat EDL. The turnover number, defined as the Ca2+ uptake divided by the number of pumps, was 1065 +/- 150 min -1 for toadfish and 1786 +/- 230 min -1 for rat EDL (p < 0.05) at 37 degrees C. The Ca2+ uptake rate of toadfish sonic muscle at 22 degree C, a typical temperature for calling toadfish, averaged 42 +/- 1% of its rate at 37 degree C. At these operating temperatures, the toadfish SR is likely to be slower than the rat fast-twitch SR, yet the toadfish sonic muscle supports more rapid contractions. One explanation for this is that the voluminous SR provides activator Ca2+ for contraction, but the abundant parvalbumin plays a major role in relaxation.

  4. Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III.

    PubMed

    Wynn, S; Teramura, M; Sato, T; Hanada, M

    2015-01-01

    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R(2) = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition.

  5. Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III

    PubMed Central

    Wynn, S.; Teramura, M.; Sato, T.; Hanada, M.

    2015-01-01

    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R2 = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition. PMID:25557676

  6. Prediction Markets for Defense Acquisition: The Devil is in the Details

    DTIC Science & Technology

    2010-05-01

    1 Bill Gates, Pete Coughlan, Noah Myung, Jeremy Arkes Professors of Economics Naval Postgraduate School Prediction Markets for Defense Acquisition...Acquisition: The Devil is in the Details 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School,Monterey,CA,93943 8. PERFORMING

  7. Estimating Logistics Burdens in Support of Acquisition Decisions

    DTIC Science & Technology

    2012-04-30

    Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to a penalty...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School,Monterey,CA,93943 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING

  8. Military Intelligence Fusion for Complex Operations: A New Paradigm

    DTIC Science & Technology

    2012-01-01

    TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) RAND Corporation,National Defense Research Institute,1776 Main...Street, P.O. Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10...Community under Contract W74V8H-06-C-0002. iii Preface This occasional paper examines how military intelligence organizations and, more broadly, the

  9. Small Business Procurement Event

    DTIC Science & Technology

    2014-08-13

    Small Business Procurement Event 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Department of the Navy,Office of Small Business Programs,720 Kennon...distribution unlimited 13. SUPPLEMENTARY NOTES NDIA 27th Navy Gold Coast Small Business Procurement Event, 12-13 Aug 2014, San Diego, CA. 14. ABSTRACT

  10. Ca2+-dependent rapid Ca2+ sensitization of contraction in arterial smooth muscle.

    PubMed

    Dimopoulos, George J; Semba, Shingo; Kitazawa, Kazuyo; Eto, Masumi; Kitazawa, Toshio

    2007-01-05

    Ca(2+) ion is a universal intracellular messenger that regulates numerous biological functions. In smooth muscle, Ca(2+) with calmodulin activates myosin light chain (MLC) kinase to initiate a rapid MLC phosphorylation and contraction. To test the hypothesis that regulation of MLC phosphatase is involved in the rapid development of MLC phosphorylation and contraction during Ca(2+) transient, we compared Ca(2+) signal, MLC phosphorylation, and 2 modes of inhibition of MLC phosphatase, phosphorylation of CPI-17 Thr38 and MYPT1 Thr853, during alpha(1) agonist-induced contraction with/without various inhibitors in intact rabbit femoral artery. Phenylephrine rapidly induced CPI-17 phosphorylation from a negligible amount to a peak value of 0.38+/-0.04 mol of Pi/mol within 7 seconds following stimulation, similar to the rapid time course of Ca(2+) rise and MLC phosphorylation. This rapid CPI-17 phosphorylation was dramatically inhibited by either blocking Ca(2+) release from the sarcoplasmic reticulum or by pretreatment with protein kinase C inhibitors, suggesting an involvement of Ca(2+)-dependent protein kinase C. This was followed by a slow Ca(2+)-independent and Rho-kinase/protein kinase C-dependent phosphorylation of CPI-17. In contrast, MYPT1 phosphorylation had only a slow component that increased from 0.29+/-0.09 at rest to the peak of 0.68+/-0.14 mol of Pi/mol at 1 minute, similar to the time course of contraction. Thus, there are 2 components of the Ca(2+) sensitization through inhibition of MLC phosphatase. Our results support the hypothesis that the initial rapid Ca(2+) rise induces a rapid inhibition of MLC phosphatase coincident with the Ca(2+)-induced MLC kinase activation to synergistically initiate a rapid MLC phosphorylation and contraction in arteries with abundant CPI-17 content.

  11. High-Speed Laser Photography

    DTIC Science & Technology

    1988-08-01

    completion of contract F04611-86-K-0018 with the Air Force Astronautics Laboratory (AFAL), Edwards AFB, CA. AFAL Project Manager was Gary Vogt. This report...assi fied 22&. NAME OF RESPONSIBLE INDIVIDUAL 22b. TE-CEPMONE NUMBER 22c. OFFICE SYMBOL ((Includ. A 1.4 C".), Gary L. Vogt (05) 375-5258 YSCF 00 FORM...CTPB Binders. A Major Transition in Solid Propellant Binder Chemistry, Paper presented to AIAA, No. 84-1236. 4. Flandro , G. A., A Simple Conceptual

  12. Variational Formulation and Finite Element Implementation of Pagano’s Theory of Laminated Plates

    DTIC Science & Technology

    1991-07-12

    ORGANIZATION (N Wmkabl,) Contract No. F33615-85-C-3213 Sc. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT...PERFORMING ORGANIZATION REPORT NUMBER (S) S. MONITORING ORGANIZATION REPORT NUMBER (S) RF Project 764779/717297 WL-TR-91-3016 6a. NAME OF PERFORMING...Wright-Patterson Air Force Base, Ohio 45433- 6553 Ba. NAME OF FUNDING/SPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER

  13. A focus on extracellular Ca2+ entry into skeletal muscle

    PubMed Central

    Cho, Chung-Hyun; Woo, Jin Seok; Perez, Claudio F; Lee, Eun Hui

    2017-01-01

    The main task of skeletal muscle is contraction and relaxation for body movement and posture maintenance. During contraction and relaxation, Ca2+ in the cytosol has a critical role in activating and deactivating a series of contractile proteins. In skeletal muscle, the cytosolic Ca2+ level is mainly determined by Ca2+ movements between the cytosol and the sarcoplasmic reticulum. The importance of Ca2+ entry from extracellular spaces to the cytosol has gained significant attention over the past decade. Store-operated Ca2+ entry with a low amplitude and relatively slow kinetics is a main extracellular Ca2+ entryway into skeletal muscle. Herein, recent studies on extracellular Ca2+ entry into skeletal muscle are reviewed along with descriptions of the proteins that are related to extracellular Ca2+ entry and their influences on skeletal muscle function and disease. PMID:28912570

  14. 8-Bromo-cAMP decreases the Ca2+ sensitivity of airway smooth muscle contraction through a mechanism distinct from inhibition of Rho-kinase.

    PubMed

    Endou, Katsuaki; Iizuka, Kunihiko; Yoshii, Akihiro; Tsukagoshi, Hideo; Ishizuka, Tamotsu; Dobashi, Kunio; Nakazawa, Tsugio; Mori, Masatomo

    2004-10-01

    To clarify whether cyclic AMP (cAMP)/cAMP-dependent protein kinase (PKA) activation and Rho-kinase inhibition share a common mechanism to decrease the Ca2+ sensitivity of airway smooth muscle contraction, we examined the effects of 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), a stable cAMP analog, and (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide dihydrochloride, monohydrate (Y-27632), a Rho-kinase inhibitor, on carbachol (CCh)-, guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS)-, 4beta-phorbol 12,13-dibutyrate (PDBu)-, and leukotriene D4 (LTD4)-induced Ca2+ sensitization in alpha-toxin-permeabilized rabbit tracheal and human bronchial smooth muscle. In rabbit trachea, CCh-induced smooth muscle contraction was inhibited by 8-BrcAMP and Y-27632 to a similar extent. However, GTPgammaS-induced smooth muscle contraction was resistant to 8-BrcAMP. In the presence of a saturating concentration of Y-27632, PDBu-induced smooth muscle contraction was completely reversed by 8-BrcAMP. Conversely, PDBu-induced smooth muscle contraction was resistant to Y-27632. In the presence of a saturating concentration of 8-BrcAMP, GTPgammaS-induced Ca2+ sensitization was also reversed by Y-27632. The 8-BrcAMP had no effect on the ATP-triggered contraction of tracheal smooth muscle that had been treated with calyculin A in rigor solutions. The 8-BrcAMP and Y-27632 additively accelerated the relaxation rate of PDBu- and GTPgammaS-treated smooth muscle under myosin light chain kinase-inhibited conditions. In human bronchus, LTD4-induced smooth muscle contraction was inhibited by both 8-BrcAMP and Y-27632. We conclude that cAMP/PKA-induced Ca2+ desensitization contains at least two mechanisms: 1) inhibition of the muscarinic receptor signaling upstream from Rho activation and 2) cAMP/PKA's preferential reversal of PKC-mediated Ca2+ sensitization in airway smooth muscle.

  15. An Assessment of Fiscal Year 2013 Beyond Yellow Ribbon Programs

    DTIC Science & Technology

    2015-01-01

    2013 Beyond Yellow Ribbon Programs 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) RAND Corporation,National Defense Research Institute,1776 Main Street, P.O...Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR

  16. Developing a Repeatable Methodology to Calculate Retrograde Planning Factors

    DTIC Science & Technology

    2015-01-01

    CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...ORGANIZATION NAME( S ) AND ADDRESS(ES) RAND Corporation,Arroyo Center,1776 Main Street, P.O. Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING...ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S REPORT NUMBER( S

  17. Global Trends and Future Warfare (Strategic Insights. Special Issue, October 2011)

    DTIC Science & Technology

    2011-10-01

    CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ...cyberspace are constructed .33 In the early 1970s Daniel Bell in The Coming of Post- Industrial Society predicted something like this when he wrote of...ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School,Center on Contemporary Conflict,Monterey,CA,93943 8. PERFORMING ORGANIZATION REPORT

  18. Building a Discourse-Tagged Corpus in the Framework of Rhetorical Structure Theory

    DTIC Science & Technology

    2001-01-01

    lmcarlnord@aol.com Daniel Marcu Information Sciences Institute University of S . California Marina del Rey, CA 90292 marcu@isi.edu Mary Ellen Okurowski...Rhetorical Structure Theory 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Department of Defense,9800 Savage Road,Fort Meade,MD,20755 8. PERFORMING

  19. Molecular Engineering for Mechanically Resilient and Stretchable Electronic Polymers and Composites

    DTIC Science & Technology

    2016-06-08

    CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0156 5c. PROGRAM ELEMENT NUMBER 6 . AUTHOR(S) Darren J. Lipomi 5d. PROJECT NUMBER 5e. TASK NUMBER...CA 92093-0448 8. PERFORMING ORGANIZATION REPORT NUMBER 9 . SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) Air Force Office of Scientific...these results to produce a new type of ultra-thin, skin-wearable solar cell that could survive many cycles of deformation without degrading

  20. Functional implications of muscle co-contraction during gait in advanced age.

    PubMed

    Lo, Justine; Lo, On-Yee; Olson, Erin A; Habtemariam, Daniel; Iloputaife, Ikechukwu; Gagnon, Margaret M; Manor, Brad; Lipsitz, Lewis A

    2017-03-01

    Older adults often exhibit high levels of lower extremity muscle co-contraction, which may be the cause or effect of age-related impairments in gait and associated falls. Normal gait requires intact executive function and thus can be slowed by challenging executive resources available to the neuromuscular system through the performance of a dual task. We therefore investigated associations between lower limb co-contraction and gait characteristics under normal and dual task conditions in healthy older adults (85.4±5.9years). We hypothesized that greater co-contraction is associated with slower gait speed during dual task conditions that stress executive and attentional abilities. Co-contraction was quantified during different phases of the gait cycle using surface electromyography (EMG) signals obtained from the anterior tibialis and lateral gastrocnemius while walking at preferred speed during normal and dual task conditions. Variables included the time difference to complete the Trail Making Test A and B (ΔTMT) and gait measures during normal or dual task walking. Higher co-contraction levels during the swing phase of both normal and dual task walking were associated with longer ΔTMT (normal: R 2 =0.25, p=0.02; dual task: R 2 =0.27, p=0.01). Co-contraction was associated with gait measures during dual task walking only; greater co-contraction levels during stride and stance were associated with slower gait speed (stride: R 2 =0.38, p=0.04; stance: R 2 =0.38, p=0.04), and greater co-contraction during stride was associated with longer stride time (R 2 =0.16, p=0.03). Our results suggest that relatively high lower limb co-contraction may explain some of the mobility impairments associated with the conduct of executive tasks in older adults. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. p,p′-DDE activates CatSper and compromises human sperm function at environmentally relevant concentrations

    PubMed Central

    Tavares, Renata S.; Mansell, Steven; Barratt, Christopher L.R.; Wilson, Stuart M.; Publicover, Stephen J.; Ramalho-Santos, João

    2013-01-01

    STUDY QUESTION Is the environmental endocrine disruptor p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) able to induce non-genomic changes in human sperm and consequently affect functional sperm parameters? SUMMARY ANSWER p,p′-DDE promoted Ca2+ flux into human sperm by activating CatSper channels even at doses found in human reproductive fluids, ultimately compromising sperm parameters important for fertilization. WHAT IS KNOWN ALREADY p,p′-DDE may promote non-genomic actions and interact directly with pre-existing signaling pathways, as already observed in other cell types. However, although often found in both male and female reproductive fluids, its effects on human spermatozoa function are not known. STUDY DESIGN, SIZE, DURATION Normozoospermic sperm samples from healthy individuals were included in this study. Samples were exposed to several p,p′-DDE concentrations for 3 days at 37°C and 5% CO2 in vitro to mimic the putative continuous exposure to this toxicant in the female reproductive tract in vivo. Shorter p,p′-DDE incubation periods were also performed in order to monitor sperm rapid Ca2+ responses. All experiments were repeated on a minimum of five sperm samples from different individuals. PARTICIPANTS/MATERIALS, SETTING, METHODS All healthy individuals were recruited at the Biosciences School, University of Birmingham, the Medical Research Institute, University of Dundee and in the Human Reproduction Service at University Hospitals of Coimbra. Intracellular Ca2+ concentration ([Ca2+]i) was monitored by imaging single spermatozoa loaded with Oregon Green BAPTA-1AM and further whole-cell patch-clamp recordings were performed to validate our results. Sperm viability and acrosomal integrity were assessed using the LIVE/DEAD sperm vitality kit and the acrosomal content marker PSA-FITC, respectively. MAIN RESULTS AND THE ROLE OF CHANCE p,p′-DDE rapidly increased [Ca2+]i (P < 0.05) even at extremely low doses (1 pM and 1 nM), with magnitudes of response up to 200%, without affecting sperm viability, except after 3 days of continuous exposure to the highest concentration tested (P < 0.05). Furthermore, experiments performed in a low Ca2+ medium demonstrated that extracellular Ca2+ influx was responsible for this Ca2+ increase (P < 0.01). Mibefradil and NNC 55-0396, both inhibitors of the sperm-specific CatSper channel, reversed the p,p′-DDE-induced [Ca2+]i rise, suggesting the participation of CatSper in this process (P < 0.05). In fact, whole-cell patch-clamp recordings confirmed CatSper as a target of p,p′-DDE action by monitoring an increase in CatSper currents of >100% (P < 0.01). Finally, acrosomal integrity was adversely affected after 2 days of exposure to p,p′-DDE concentrations, suggesting that [Ca2+]i rise may cause premature acrosome reaction (P < 0.05). LIMITATIONS, REASONS FOR CAUTION This is an in vitro study, and caution must be taken when extrapolating the results. WIDER IMPLICATIONS OF THE FINDINGS A novel non-genomic p,p′-DDE mechanism specific to sperm is shown in this study. p,p′-DDE was able to induce [Ca2+]i rise in human sperm through the opening of CatSper consequently compromising male fertility. The promiscuous nature of CatSper activation may predispose human sperm to the action of some persistent endocrine disruptors. STUDY FUNDING/COMPETING INTEREST(S) The study was supported by both the Portuguese National Science Foundation (FCT; PEst-C/SAU/LA0001/2011) and the UK Wellcome Trust (Grant #86470). SM was supported by the Infertility Research Trust. RST is a recipient of a PhD fellowship from FCT (SFRH/BD/46002/2008). None of the authors has any conflict of interest to declare. PMID:24067601

  2. The effects and possible mechanism of β2AR gene expression in cardiocytes of canines with heart failure.

    PubMed

    Gong, Haibin; San, Yu; Wang, Lei; Lv, Qian; Chen, Libin

    2017-07-01

    The objective of the present study was to observe the changes of β 2 -adrenergic receptor (β 2 AR) protein expression in a canine model of heart failure (HF), and the function of cardiocytes after transfection with Adv-β 2 AR. The canine model of chronic HF was induced by rapid right ventricular pacing and cardiocytes were isolated with collagenase II. Cardiocytes were transfected with Adv-β 2 AR to observe contractile function with a motion edge-detection system of single cells. Expression of β 2 AR protein in cardiocytes was measured by immunoblotting and the levels of intracellular cAMP were measured by ELISA. Compared with the control group (the sham group), the expression of β 2 AR protein in HF cardiocytes did not change, but the basal (1 mM Ca 2+ ) contraction amplitude percentage (1.809±0.922 vs. 1.120±0.432%, P<0.05), the maximum contraction amplitude percentage (14.855±2.377 vs. 10.784±2.675%, P<0.01) and the basal levels of intracellular cAMP (9.39±2.54 vs. 5.26±0.95 pmol/ml, n=6, P<0.05) of HF cardiocytes were significantly decreased. However, when HF cardiocytes were transfected with Adv-β 2 AR and cultured for 48 h, compared with the non-transfected group, the basal contraction amplitude percentage (0.851±0.324 vs. 1.629±0.522%, P<0.05), the maximum contraction amplitude percentage (9.260±2.208% vs. 12.205±1.437%, P<0.01) and the basal levels of intracellular cAMP (5.26±0.95 vs. 9.03±1.03 pmol/ml, n=6, P<0.05) of cardiocytes in the transfected group were significantly increased. In conclusion, the expression of β 2 AR protein in HF cardiocytes did not change, but contraction function was impaired. The moderate overexpression of β 2 AR gene in the HF cardiocytes increased the levels of intracellular cAMP and improved contraction function.

  3. Pre- and post-synaptic dopamine imaging and its relation with frontostriatal cognitive function in Parkinson disease: PET studies with [11C]NNC 112 and [18F]FDOPA.

    PubMed

    Cropley, Vanessa L; Fujita, Masahiro; Bara-Jimenez, William; Brown, Amira K; Zhang, Xiang-Yang; Sangare, Janet; Herscovitch, Peter; Pike, Victor W; Hallett, Mark; Nathan, Pradeep J; Innis, Robert B

    2008-07-15

    Frontostriatal cognitive dysfunction is common in Parkinson disease (PD), but the explanation for its heterogeneous expressions remains unclear. This study examined the dopamine system within the frontostriatal circuitry with positron emission tomography (PET) to investigate pre- and post-synaptic dopamine function in relation to the executive processes in PD. Fifteen non-demented PD patients and 14 healthy controls underwent [(18)F]FDOPA (for dopamine synthesis) and [(11)C]NNC 112 (for D(1) receptors) PET scans and cognitive testing. Parametric images of [(18)F]FDOPA uptake (K(i)) and [(11)C]NNC 112 binding potential (BP(ND)) were calculated using reference tissue models. Group differences in K(i) and BP(ND) were assessed with both volume of interest and statistical parametric mapping, and were correlated with cognitive tests. Measurement of [(18)F]FDOPA uptake in cerebral cortex was questionable because of higher K(i) values in white than adjacent gray matter. These paradoxical results were likely to be caused by violations of the reference tissue model assumption rendering interpretation of cortical [(18)F]FDOPA uptake in PD difficult. We found no regional differences in D(1) receptor density between controls and PD, and no overall differences in frontostriatal performance. Although D(1) receptor density did not relate to frontostriatal cognition, K(i) decreases in the putamen predicted performance on the Wisconsin Card Sorting Test in PD only. These results suggest that striatal dopamine denervation may contribute to some frontostriatal cognitive impairment in moderate stage PD.

  4. Cellular properties of extensor carpi radialis brevis and trapezius muscles in healthy males and females.

    PubMed

    Green, Howard J; Ranney, Don; Burnett, Margaret; Iqbal, Sobia; Kyle, Natasha; Lounsbury, David; Ouyang, Jing; Tupling, A Russell; Smith, Ian C; Stewart, Riley; Tick, Heather

    2015-11-01

    In this study, we sought to determine whether differences in cellular properties associated with energy homeostasis could explain the higher incidence of work-related myalgia in trapezius (TRAP) compared with extensor carpi radialis brevis (ECRB). Tissue samples were obtained from the ECRB (n = 19) and TRAP (n = 17) of healthy males and females (age 27.9 ± 2.2 and 28.1 ± 1.5 years, respectively; mean ± SE) and analyzed for properties involved in both ATP supply and utilization. The concentration of ATP and the maximal activities of creatine phosphokinase, phosphorylase, and phosphofructokinase were higher (P < 0.05) in ECRB than TRAP. Succinic dehydrogenase, citrate synthase, and cytochrome c oxidase were not different between muscles. The ECRB also displayed a higher concentration of Na(+)-K(+)-ATPase and greater sarcoplasmic reticulum Ca(2+) release and uptake. No differences existed between muscles for either monocarboxylate transporters or glucose transporters. It is concluded that the potentials for high-energy phosphate transfer, glycogenolysis, glycolysis, and excitation-contraction coupling are higher in ECRB than TRAP. Histochemical measurements indicated that the muscle differences are, in part, related to differing amounts of type II tissue. Depending on the task demands, the TRAP may experience a greater metabolic and excitation-contraction coupling strain than the ECRB given the differences observed.

  5. Osmolality- and Na+ -dependent effects of hyperosmotic NaCl solution on contractile activity and Ca2+ cycling in rat ventricular myocytes.

    PubMed

    Ricardo, Rafael A; Bassani, Rosana A; Bassani, José W M

    2008-01-01

    Hypertonic NaCl solutions have been used for small-volume resuscitation from hypovolemic shock. We sought to identify osmolality- and Na(+)-dependent components of the effects of the hyperosmotic NaCl solution (85 mOsm/kg increment) on contraction and cytosolic Ca(2+) concentration ([Ca(2+)](i)) in isolated rat ventricular myocytes. The biphasic change in contraction and Ca(2+) transient amplitude (decrease followed by recovery) was accompanied by qualitatively similar changes in sarcoplasmic reticulum (SR) Ca(2+) content and fractional release and was mimicked by isosmotic, equimolar increase in extracellular [Na(+)] ([Na(+)](o)). Raising osmolality with sucrose, however, augmented systolic [Ca(2+)](i) monotonically without change in SR parameters and markedly decreased contraction amplitude and diastolic cell length. Functional SR inhibition with thapsigargin abolished hyperosmolality effects on [Ca(2+)](i). After 15-min perfusion, both hyperosmotic solutions slowed mechanical relaxation during twitches and [Ca(2+)](i) decline during caffeine-evoked transients, raised diastolic and systolic [Ca(2+)](i), and depressed systolic contractile activity. These effects were greater with sucrose solution, and were not observed after isosmotic [Na(+)](o) increase. We conclude that under the present experimental conditions, transmembrane Na(+) redistribution apparently plays an important role in determining changes in SR Ca(2+) mobilization, which markedly affect contractile response to hyperosmotic NaCl solutions and attenuate the osmotically induced depression of contractile activity.

  6. Anti-Cyanide Drugs

    DTIC Science & Technology

    1988-05-01

    Fort Detrick, Frederick, Maryland 21701-S012 * Contract No. DAMD7-85-C-5OS6 Department of Chemistry Howard University Washington, D. C. 20059 ED TIC...REPORT NUMBER(S) 68. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Howard University (If appicabie) Department...pr&i Contract No. DAMD17-85-C-5086 D TAB J’utificat Ion - Department of Chemistry Howard University Washington, D. C. 20059 By.Dlstribution

  7. The gamma-aminobutyric acid uptake inhibitor, tiagabine, is anticonvulsant in two animal models of reflex epilepsy.

    PubMed

    Smith, S E; Parvez, N S; Chapman, A G; Meldrum, B S

    1995-02-06

    The effects of i.p. administration of the gamma-aminobutyric acid (GABA) uptake inhibitors R(-)N-(4,4-di(3-methylthien-2-yl)-but-3-enyl) nipecotic acid hydrochloride (tiagabine; molecular weight 412.0), (1-(2-(((diphenylmethylene)-amino)oxy)ethyl)-1,2,5,6-tetrahydro-3- pyridinecarboxylic acid hydrochloride (NNC-711; molecular weight 386.9), and (+/-)-nipecotic acid (molecular weight 128.2) are compared with those of carbamazepine (molecular weight 236.3) on sound-induced seizures and locomotor performance in genetically epilepsy-prone (GEP) rats. The ED50 value against clonic seizures (in mumol kg-1 at the time of maximal anticonvulsant effect) for tiagabine was 23 (0.5 h), and for NNC-711 was 72 (1 h), and for carbamazepine was 98 (2 h). (+/-)-Nipecotic acid (0.4-15.6 mmol kg-1) was not anticonvulsant. High doses of NNC-711 (207-310 mumol kg-1) and of (+/-)-nipecotic acid (39-78 mmol kg-1) induced ataxia and myoclonic seizures 0.25-1 h. Tiagabine and carbamazepine did not induce myoclonic seizures and had similar therapeutic indices (locomotor deficit ED50/anticonvulsant ED50) ranging from 0.4 to 1.9. In Papio papio, we observed a reduction in photically induced myoclonic seizures with tiagabine (2.4 mumol kg-1 i.v.) accompanied with neurological impairment. Tiagabine has comparable anticonvulsant action to carbamazepine in rats and has anticonvulsant effects in non-human primates supporting the potential use of inhibitors of GABA uptake as therapy for epilepsy.

  8. National Dam Safety Program. Wallace Lake Dam (MO 31263), White River Basin, Carter County, Missouri. Phase I Inspection Report.

    DTIC Science & Technology

    1980-08-01

    ARMY ENGINEER DISTRICT, ST. LOUIS D I Ms FOPATE OF MISSOURI E L E C T p D3 AUGUST, 19ue pTE4ENA lo1 9 o85 UNCLASSIFIED SECURITY CLASSIFICATION OF THIS...Anderson Engineering, Inc. DACW4 3-8,0-C-A673 9 . PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGJAM EL"gNT. PROJ&QT. TASK U.S. Army Engineer District...the-work-reported was accomplished. Leave blank in in-house reports. Block 9 . Performing Organization Name and Address. For in-house reports enter the

  9. TNFalpha -308 C-->t and -863 C-->a polymorphisms and spermiogram characteristics.

    PubMed

    Kurz, Christine; Bentz, Eva-Katrin; Denschlag, Dominik; Berner, Isabel; Keck, Christoph; Tempfer, Clemens B; Pietrowski, Detlef

    2008-01-01

    Genetic factors may play a role in male infertility. In a prospective case-control study, we assessed the allele and genotype frequencies of the TNFalpha -308 C-->T and -863 C-->A polymorphisms, detected by PCR of sperm DNA, of 577 Caucasian men recruited in an infertility clinic. Semen sampling was performed and spermiogram results were correlated to genetic data. The allele frequencies of the TNFalpha -308 C-->T and -863 C-->A polymorphisms were not significantly different between non-normozoospermic (n = 447) and normozoospermic (n = 130) men [758/894 (85%) and 134/894 (15%) vs. 213/269 (82%) and 43/260 (18%), p = 0.5, odds ratio (OR) 1.1, 95% confidence interval (CI) 0.74-1.76, and 749/894 (84%) and 145/894 (16%) vs. 212/260 (82%) and 48/260 (18%), p = 0.4, OR 1.2, 95% CI 0.78-1.76, respectively]. The genotype frequencies of the TNFalpha -308 C-->T and -863 C-->A polymorphisms were also not significantly different between non-normozoospermic and normozoospermic men. In addition, mutant alleles were not overrepresented in subgroups of men with the oligoasthenoteratozoospermia syndrome and asthenozoospermia. The TNFalpha -308 C-->T and -863 C-->A polymorphisms are not associated with spermiogram characteristics and do not represent molecular markers for genetic susceptibility to male infertility. Copyright 2008 S. Karger AG, Basel.

  10. Cooling-induced contraction in ovine airways smooth muscle.

    PubMed

    Mustafa, S M; Pilcher, C W; Williams, K I

    1999-02-01

    The mechanism of cold-induced bronchoconstriction is poorly understood. This prompted the present study whose aim was to determine the step-wise direct effect of cooling on smooth muscle of isolated ovine airways and analyse the role of calcium in the mechanisms involved. Isolated tracheal strips and bronchial segments were suspended in organ baths containing Krebs' solution for isometric tension recording. Tissue responses during stepwise cooling from 37 to 5 degrees C were examined. Cooling induced a rapid and reproducible contraction proportional to cooling temperature in ovine tracheal and bronchial preparations which was epithelium-independent. On readjustment to 37 degrees C the tone returned rapidly to basal level. Maximum contraction was achieved at a temperature of 5 degrees C for trachea and 15 degrees C for bronchiole. Cooling-induced contractions (CIC) was resistant to tetrodotoxin (1; 10 micrometer), and not affected by the muscarinic antagonist atropine (1 micrometer) or the alpha-adrenergic antagonist phentolamine (1 micrometer), or the histamine H1-antagonist mepyramine (1 micrometer) or indomethacin (1 micrometer). Ca2+ antagonists (nifedipine and verapamil) and Mn2+ raised tracheal but not bronchiolar tone and augmented CIC. Incubation in Ca2+-free, EGTA-containing Krebs' solution for 5 min had no effect on CIC, although it significantly reduced KCl-induced contraction by up to 75%. Cooling inhibited Ca2+ influx measured using 45Ca2+ uptake. Caffeine (100 micrometer) significantly inhibited CIC. The results show that cooling-induced contractions do not appear to involve activation of nerve endings, all surface reception systems or Ca2+ influx. However, CIC is mainly dependent on release of intracellular Ca2+. Copyright 1999 The Italian Pharmacological Society.

  11. The role of TRPP2 in agonist-induced gallbladder smooth muscle contraction.

    PubMed

    Zhong, Xingguo; Fu, Jie; Song, Kai; Xue, Nairui; Gong, Renhua; Sun, Dengqun; Luo, Huilai; He, Wenzhu; Pan, Xiang; Shen, Bing; Du, Juan

    2016-04-01

    TRPP2 channel protein belongs to the superfamily of transient receptor potential (TRP) channels and is widely expressed in various tissues, including smooth muscle in digestive gut. Accumulating evidence has demonstrated that TRPP2 can mediate Ca(2+) release from Ca(2+) stores. However, the functional role of TRPP2 in gallbladder smooth muscle contraction still remains unclear. In this study, we used Ca(2+) imaging and tension measurements to test agonist-induced intracellular Ca(2+) concentration increase and smooth muscle contraction of guinea pig gallbladder, respectively. When TRPP2 protein was knocked down in gallbladder muscle strips from guinea pig, carbachol (CCh)-evoked Ca(2+) release and extracellular Ca(2+) influx were reduced significantly, and gallbladder contractions induced by endothelin 1 and cholecystokinin were suppressed markedly as well. CCh-induced gallbladder contraction was markedly suppressed by pretreatment with U73122, which inhibits phospholipase C to terminate inositol 1,4,5-trisphosphate receptor (IP3) production, and 2-aminoethoxydiphenyl borate (2APB), which inhibits IP3 recepor (IP3R) to abolish IP3R-mediated Ca(2+) release. To confirm the role of Ca(2+) release in CCh-induced gallbladder contraction, we used thapsigargin (TG)-to deplete Ca(2+) stores via inhibiting sarco/endoplasmic reticulum Ca(2+)-ATPase and eliminate the role of store-operated Ca(2+) entry on the CCh-induced gallbladder contraction. Preincubation with 2 μmol L(-1) TG significantly decreased the CCh-induced gallbladder contraction. In addition, pretreatments with U73122, 2APB or TG abolished the difference of the CCh-induced gallbladder contraction between TRPP2 knockdown and control groups. We conclude that TRPP2 mediates Ca(2+) release from intracellular Ca(2+) stores, and has an essential role in agonist-induced gallbladder muscle contraction.

  12. 14 CFR 1260.15 - Format and numbering.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Fiscal Year 2004 would be NNC04AA01H and NNC04AA02H. (7) The Catalog of Federal Domestic Assistance (CFDA... will be applied as follows: (1) Agency prefix. NASA's agency prefix shall be represented by the...

  13. 41 CFR 102-39.85 - What information am I required to report?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Transportation and Asset Management (MT), 1800 F Street, NW., Washington, DC 20405. (c) Report control number... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What information am I required to report? 102-39.85 Section 102-39.85 Public Contracts and Property Management Federal Property...

  14. Subgrouping Chronic Fatigue Syndrome Patients by Genetic and Immune Profiling

    DTIC Science & Technology

    2013-10-01

    CONTRACTING ORGANIZATION : Stanford University Stanford, CA 94305-2004 REPORT DATE...Rosemary Fernandez 5e. TASK NUMBER E-Mail: gilberto@stanford.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...8. PERFORMING ORGANIZATION REPORT NUMBER Stanford University Stanford, CA 94305-2004 9. SPONSORING / MONITORING AGENCY NAME

  15. In vitro relaxant and spasmolytic effects of essential oil of Pistacia integerrima Stewart ex Brandis Galls.

    PubMed

    Shirole, R L; Shirole, N L; Saraf, M N

    2015-06-20

    Pistacia integerrima J.L. Stewart ex Brandis (Family: Anacardiaceae) galls are used in Indian ethnomedicine for its anti-asthmatic, sedative and spasmolytic properties, however, there are no scientific studies demonstrating its spasmolytic activity. The present investigation deals with the evaluation of relaxant and spasmolytic activities of the essential oil isolated from the galls of Pistacia integerrima J.L. Stewart ex Brandis (EOPI). In vitro pharmacological assays were carried out on rabbit jejunum spontaneous contractions, guinea pig ileum. The present investigation studied the relaxation of basal tone of isolated guinea pig ileum by possible involvement of NO, prostaglandins, membrane Na(+) channels, potassium channel, enteric nervous system, adrenoceptors, Ca(2+) channels. Additional studies were conducted for comparison of the relaxant effects of EOPI on CaCl2 induced contraction in calcium free tyrode solution, effect on nifedipine insensitive component of ACh-induced contraction and on the contractile machinery to intracellular [Ca(2+)] on isolated guinea pig ileum. EOPI at non-relaxing dose potentiated the isoprenaline induced relaxation of rabbit jejunum. EOPI (50 µg/mL) exhibited 28% relaxation of basal tone of 60 mM K(+) induced contraction which is unaltered by preincubation with 0.5 mM hexamethonium, 0.5 µM Tetrodotoxin, 1 µM indomethacin, and 100 µM L-NG-Nitroarginine Methyl Ester (L-NAME). EOPI inhibited Ca(2+) induced contraction of isolated guinea pig ileum in Ca(2+) free medium. EOPI (10 µg/ml) potentiated the reversal of a KCl-induced tonic contraction has been observed in Ca(2+) free medium. The present investigation reinforces the use of Pistacia integerrima Stewart ex Brandis as antispasmodic in folk medicine. Moreover, it is demonstrated the involvement of β- adrenoceptors and calcium channels in this activity, but not the participation of nicotinic receptors, Na(+) channels, prostaglandins or nitric oxide. Copyright © 2015. Published by Elsevier Ireland Ltd.

  16. Modafinil inhibits K(Ca)3.1 currents and muscle contraction via a cAMP-dependent mechanism.

    PubMed

    Choi, Shinkyu; Kim, Moon Young; Joo, Ka Young; Park, Seonghee; Kim, Ji Aee; Jung, Jae-Chul; Oh, Seikwan; Suh, Suk Hyo

    2012-07-01

    Modafinil has been used as a psychostimulant for the treatment of narcolepsy. However, its primary mechanism of action remains elusive. Therefore, we examined the effects of modafinil on K(Ca)3.1 channels and vascular smooth muscle contraction. K(Ca)3.1 currents and channel activity were measured using a voltage-clamp technique and inside-out patches in mouse embryonic fibroblast cell line, NIH-3T3 fibroblasts. Intracellular adenosine 3',5'-cyclic monophosphate (cAMP) concentration was measured, and the phosphorylation of K(Ca)3.1 channel protein was examined using western blotting in NIH-3T3 fibroblasts and/or primary cultured mouse aortic smooth muscle cells (SMCs). Muscle contractions were recorded from mouse aorta and rat pulmonary artery by using a myograph developed in-house. Modafinil was found to inhibit K(Ca)3.1 currents in a concentration-dependent manner, and the half-maximal inhibition (IC(50)) of modafinil for the current inhibition was 6.8 ± 0.7 nM. The protein kinase A (PKA) activator forskolin also inhibited K(Ca)3.1 currents. The inhibitory effects of modafinil and forskolin on K(Ca)3.1 currents were blocked by the PKA inhibitors PKI(14-22) or H-89. In addition, modafinil relaxed blood vessels (mouse aorta and rat pulmonary artery) in a concentration-dependent manner. Modafinil increased cAMP concentrations in NIH-3T3 fibroblasts or primary cultured mouse aortic SMCs and phosphorylated K(Ca)3.1 channel protein in NIH-3T3 fibroblasts. However, open probability and single-channel current amplitudes of K(Ca)3.1 channels were not changed by modafinil. From these results, we conclude that modafinil inhibits K(Ca)3.1 channels and vascular smooth muscle contraction by cAMP-dependent phosphorylation, suggesting that modafinil can be used as a cAMP-dependent K(Ca)3.1 channel blocker and vasodilator. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Motor Variability during Sustained Contractions Increases with Cognitive Demand in Older Adults

    PubMed Central

    Vanden Noven, Marnie L.; Pereira, Hugo M.; Yoon, Tejin; Stevens, Alyssa A.; Nielson, Kristy A.; Hunter, Sandra K.

    2014-01-01

    To expose cortical involvement in age-related changes in motor performance, we compared steadiness (force fluctuations) and fatigability of submaximal isometric contractions with the ankle dorsiflexor muscles in older and young adults and with varying levels of cognitive demand imposed. Sixteen young (20.4 ± 2.1 year: 8 men, 9 women) and 17 older adults (68.8 ± 4.4 years: 9 men, 8 women) attended three sessions and performed a 40 s isometric contraction at 5% maximal voluntary contraction (MVC) force followed by an isometric contraction at 30% MVC until task failure. The cognitive demand required during the submaximal contractions in each session differed as follows: (1) high-cognitive demand session where difficult mental math was imposed (counting backward by 13 from a 4-digit number); (2) low-cognitive demand session which involved simple mental math (counting backward by 1); and (3) control session with no mental math. Anxiety was elevated during the high-cognitive demand session compared with other sessions for both age groups but more so for the older adults than young adults (p  < 0.05). Older adults had larger force fluctuations than young adults during: (1) the 5% MVC task as cognitive demand increased (p  = 0.007), and (2) the fatiguing contraction for all sessions (p  = 0.002). Time to task failure did not differ between sessions or age groups (p  > 0.05), but the variability between sessions (standard deviation of three sessions) was greater for older adults than young (2.02 ± 1.05 vs. 1.25 ± 0.51 min, p  < 0.05). Thus, variability in lower limb motor performance for low- and moderate-force isometric tasks increased with age and was exacerbated when cognitive demand was imposed, and may be related to modulation of synergist and antagonist muscles and an altered neural strategy with age originating from central sources. These data have significant implications for cognitively demanding low-force motor tasks that are relevant to functional and ergonomic in an aging workforce. PMID:24904410

  18. Compilation of Reprints Number 64.

    DTIC Science & Technology

    1987-11-01

    EFFECT 01 llt’ItRO(;lNEN II 1 S IN "D)" ON Till: DUlCA reprint R..VIT OF 6) D tI, PERFORMING ORG. REPORT NUMBER 7 AUTHoR(.) S CONTRACT OR GRANT NUMBER...I MENKt;, WILLI:\\M NO0() 14- 84 - C- 0218 9 PERFORMING ORGANIZATION NAME AND ADORESS 10 PROGRAM ELEMENT, PROJECT TASK AREA & WORK UNIT NUMBERS...mainly increase it. We did not identify any major effect of scatterer aspect ratio on the decay rate in the one relevant test that we performed (dikes

  19. A Review and Analysis of Upgrades to Naval and Air Force Aircraft to Identify Similarities and Trends from Fiscal Year 1998 to Fiscal Year 2013

    DTIC Science & Technology

    2013-06-30

    5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School,Graduate School of Business and Public Policy,Monterey,CA,93943 8. PERFORMING...ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11. SPONSOR/MONITOR’S REPORT

  20. Ent-7α-acetoxytrachyloban-18-oic acid and ent-7α-hydroxytrachyloban-18-oic acid from Xylopia langsdorfiana A. St-Hil. & Tul. modulate K(+) and Ca(2+) channels to reduce cytosolic calcium concentration on guinea pig ileum.

    PubMed

    Santos, Rosimeire F; Martins, Italo R R; Travassos, Rafael A; Tavares, Josean F; Silva, Marcelo S; Paredes-Gamero, Edgar J; Ferreira, Alice T; Nouailhetas, Viviane L A; Aboulafia, Jeannine; Rigoni, Vera L S; da Silva, Bagnólia A

    2012-03-05

    In this study we investigated the mechanism underlying the spasmolytic action of ent-7α-acetoxytrachyloban-18-oic acid (trachylobane-360) and ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318), diterpenes obtained from Xylopia langsdorfiana, on guinea pig ileum. Both compounds inhibited histamine-induced cumulative contractions (slope=3.5±0.9 and 4.4±0.7) that suggests a noncompetitive antagonism to histaminergic receptors. CaCl(2)-induced contractions were nonparallelly and concentration-dependently reduced by both diterpenes, indicating blockade of calcium influx through voltage-dependent calcium channels (Ca(v)). The Ca(v) participation was confirmed since both trachylobanes equipotently relaxed ileum pre-contracted with S-(-)-Bay K8644 (EC(50)=3.5±0.7×10-(5) and 1.1±0.2×10-(5)M) and KCl (EC(50)=5.5±0.3×10-(5) and 1.4±0.2×10-(5)M). K(+) channels participation was confirmed since diterpene-induced relaxation curves were significantly shifted to right in the presence of 5mM tetraethylammonium (TEA(+)) (EC(50)=0.5±0.04×10-(4) and 2.0±0.5×10-(5)M). ATP-sensitive K(+) channel (K(ATP)), voltage activated K(+) channels (K(V)), small conductance calcium-activated K(+) channels (SK(Ca)) or big conductance calcium-activated K(+) channels (BK(Ca)) did not seem to participate of trachylobane-360 spasmolytic action. However trachylobane-318 modulated positively K(ATP), K(V) and SK(Ca) (EC(50)=1.1±0.3×10-(5), 0.7±0.2×10-(5) and 0.7±0.2×10-(5)M), but not BK(Ca). A fluorescence analysis technique confirmed the decrease of cytosolic calcium concentration ([Ca(2+)](c)) induced by both trachylobanes in ileal myocytes. In conclusion, trachylobane-360 and trachylobane-318 induced spasmolytic activity by K(+) channel positive modulation and Ca(2+) channel blockade, which results in [Ca(2+)](c) reduction at cellular level leading to smooth muscle relaxation. Copyright © 2011. Published by Elsevier B.V.

  1. Concreteness and context availability in lexical decision tasks.

    PubMed

    Levy-Drori, Shelly; Henik, Avishai

    2006-01-01

    Three experiments were carried out to elucidate the origins of the concreteness (C) effect in a lexical decision task. The first experiment was a replication of the work of Schwanenflugel et al. (1988) and Van Hell and De Groot (1998), who presented the context availability (CA) hypothesis. In this experiment CA seemed to be a dominant factor. Familiarity (FAM) was not incorporated in the ANOVA, but a regression analysis and negative correlation between C and FAM in the groups matched on CA showed that FAM could explain the disappearance of the C effect. Experiment 2 controlled FAM and revealed a C effect, although concrete and abstract words were matched on CA. Experiment 3 controlled C and FAM and revealed a CA effect. The current data emphasize the importance of controlling FAM and CA in examining the C effect in a lexical decision task and support a revised version of the dual-coding theory.

  2. Expression pattern of NMDA receptors reveals antiepileptic potential of apigenin 8-C-glucoside and chlorogenic acid in pilocarpine induced epileptic mice.

    PubMed

    Aseervatham, G Smilin Bell; Suryakala, U; Doulethunisha; Sundaram, S; Bose, P Chandra; Sivasudha, T

    2016-08-01

    The present study was aimed to evaluate the effect of apigenin 8-C-glucoside (Vitexin) and chlorogenic acid on epileptic mice induced by pilocarpine and explored its possible mechanisms. Intraperitonial administration of pilocarpine (85mg/kg) induced seizure in mice was assessed by behavior observations, which is significantly (p>0.05) reduced by apigenin 8-C-glucoside (AP8CG) (10mg/kg) and chlorogenic acid (CA) (5mg/kg), similar to diazepam. Seizure was accompanied by an imbalance in the levels of Gamma-aminobutyric acid (GABA) and glutamate in the pilocarpine administered group. Moreover, convulsion along with reduced acetylcholinesterase, increased monoamine oxidase and oxidative stress was observed in epileptic mice brain. AP8CG and CA significantly restored back to normal levels even at lower doses. Further, increased lipid peroxidation and nitrite content was also significantly attenuated by AP8CG and CA. However, CA was found to be more effective when compared to AP8CG. In addition, the mRNA expression of N-methyl-d-aspartate receptor (NMDAR), mGluR1 and mGlu5 was significantly (P≤0.05) inhibited by AP8CG and CA in a lower dose. The mRNA expression of GRIK1 did not differ significantly in any of the group and showed a similar pattern of expression. Our result shows that AP8CG and CA selectively inhibit NMDAR, mGluR1 and mGlu5 expression. Modification in the provoked NMDAR calcium response coupled with neuronal death. Hence, these findings underline that the polyphenolics, AP8CG and CA have exerted antiepileptic and neuroprotective activity by suppressing glutamate receptors. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. ERCC1 rs3212986 A/C polymorphism is not associated with chemotherapy treatment outcomes in gastric cancer patients: evidence from 11 publications in Chinese populations

    PubMed Central

    Wang, Yuemei; Wang, Xiaowei

    2018-01-01

    Background A number of studies have investigated the roles of excision repair cross-complementation group 1 (ERCC1) gene rs3212986 polymorphisms as potential biomarkers in gastric cancer (GC). However, the results were inconsistent. Here, we performed a meta-analysis to explore ERCC1 rs3212986 polymorphisms in the chemotherapy response and clinical outcome of GC. Methods PubMed, Embase, and Web of Science were searched up to July 28, 2017, for studies on the association between ERCC1 rs3212986 A/C polymorphisms and response to chemotherapy as well as overall survival time of GC. A fixed-effect or random-effect model was used to calculate the pooled odds ratios (ORs) based on the results from the heterogeneity tests. Results The result revealed that there was no significant association between the ERCC1 rs3212986 A/C polymorphism and response to chemotherapy in GC under comparison models (AA + CA versus CC, OR 0.95, P=0.80, AA versus CA, OR 0.85, P=0.55, AA versus CC, OR 0.74, P=0.47). Further identification suggested that ERCC1 rs3212986 A/C polymorphisms were not linked with the overall survival of GC (AA + CA versus CC, OR 1.09, P=0.52, AA versus CA, OR 1.05, P=0.85, AA versus CC, OR 1.43, P=0.23). Conclusion Our meta-analysis indicated that the ERCC1 rs3212986 A/C polymorphism was not associated with response to chemotherapy or overall survival time in GC. Well-designed studies with larger sample sizes and more ethnic groups should be performed to further validate our results. PMID:29302191

  4. Contractile reserve and intracellular calcium regulation in mouse myocytes from normal and hypertrophied failing hearts

    NASA Technical Reports Server (NTRS)

    Ito, K.; Yan, X.; Tajima, M.; Su, Z.; Barry, W. H.; Lorell, B. H.; Schneider, M. (Principal Investigator)

    2000-01-01

    Mouse myocyte contractility and the changes induced by pressure overload are not fully understood. We studied contractile reserve in isolated left ventricular myocytes from mice with ascending aortic stenosis (AS) during compensatory hypertrophy (4-week AS) and the later stage of early failure (7-week AS) and from control mice. Myocyte contraction and [Ca(2+)](i) transients with fluo-3 were measured simultaneously. At baseline (0.5 Hz, 1.5 mmol/L [Ca(2+)](o), 25 degrees C), the amplitude of myocyte shortening and peak-systolic [Ca(2+)](i) in 7-week AS were not different from those of controls, whereas contraction, relaxation, and the decline of [Ca(2+)](i) transients were slower. In response to the challenge of high [Ca(2+)](o), fractional cell shortening was severely depressed with reduced peak-systolic [Ca(2+)](i) in 7-week AS compared with controls. In response to rapid pacing stimulation, cell shortening and peak-systolic [Ca(2+)](i) increased in controls, but this response was depressed in 7-week AS. In contrast, the responses to both challenge with high [Ca(2+)](o) and rapid pacing in 4-week AS were similar to those of controls. Although protein levels of Na(+)-Ca(2+) exchanger were increased in both 4-week and 7-week AS, the ratio of SR Ca(2+)-ATPase to phospholamban protein levels was depressed in 7-week AS compared with controls but not in 4-week AS. This was associated with an impaired capacity to increase sarcoplasmic reticulum Ca(2+) load during high work states in 7-week AS myocytes. In hypertrophied failing mouse myocytes, depressed contractile reserve is related to an impaired augmentation of systolic [Ca(2+)](i) and SR Ca(2+) load and simulates findings in human failing myocytes.

  5. Computer modeling of siRNA knockdown effects indicates an essential role of the Ca2+ channel alpha2delta-1 subunit in cardiac excitation-contraction coupling.

    PubMed

    Tuluc, Petronel; Kern, Georg; Obermair, Gerald J; Flucher, Bernhard E

    2007-06-26

    L-type Ca(2+) currents determine the shape of cardiac action potentials (AP) and the magnitude of the myoplasmic Ca(2+) signal, which regulates the contraction force. The auxiliary Ca(2+) channel subunits alpha(2)delta-1 and beta(2) are important regulators of membrane expression and current properties of the cardiac Ca(2+) channel (Ca(V)1.2). However, their role in cardiac excitation-contraction coupling is still elusive. Here we addressed this question by combining siRNA knockdown of the alpha(2)delta-1 subunit in a muscle expression system with simulation of APs and Ca(2+) transients by using a quantitative computer model of ventricular myocytes. Reconstitution of dysgenic muscle cells with Ca(V)1.2 (GFP-alpha(1C)) recapitulates key properties of cardiac excitation-contraction coupling. Concomitant depletion of the alpha(2)delta-1 subunit did not perturb membrane expression or targeting of the pore-forming GFP-alpha(1C) subunit into junctions between the outer membrane and the sarcoplasmic reticulum. However, alpha(2)delta-1 depletion shifted the voltage dependence of Ca(2+) current activation by 9 mV to more positive potentials, and it slowed down activation and inactivation kinetics approximately 2-fold. Computer modeling revealed that the altered voltage dependence and current kinetics exert opposing effects on the function of ventricular myocytes that in total cause a 60% prolongation of the AP and a 2-fold increase of the myoplasmic Ca(2+) concentration during each contraction. Thus, the Ca(2+) channel alpha(2)delta-1 subunit is not essential for normal Ca(2+) channel targeting in muscle but is a key determinant of normal excitation and contraction of cardiac muscle cells, and a reduction of alpha(2)delta-1 function is predicted to severely perturb normal heart function.

  6. Epigenetic Testing for Breast Cancer Risk Stratification

    DTIC Science & Technology

    2014-06-01

    associated cancer. None of the genes met all of these criteria, PECI and GSTP1 fulfilled most so were advanced for further assessment. IRF7 and VCAN...included: PECI, IRF7, VCAN, GNE, PSAT1, HS3ST2, CCND2, WDR66, GSTP1 , APC, and RASF1A. Task 2: Establish epigenetic regulation of gene expression by...0.05 PSAT1 0.75 0 d0.14 – 0.51 HS3ST2 0.83 0.02 d0.14 - 0.38 CCND1 0.85 0.31 d0.33 - 0.66 WDR66 0.8 0.1 c0.89 GSTP1 0.77 0 c0.22 APC 0.85 0.16

  7. 32 CFR Appendix C to Part 327 - DeCA Blanket Routine Uses

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false DeCA Blanket Routine Uses C Appendix C to Part...) PRIVACY PROGRAM DEFENSE COMMISSARY AGENCY PRIVACY ACT PROGRAM Pt. 327, App. C Appendix C to Part 327—DeCA... letting of a contract, or the issuance of a license, grant, or other benefit. (c) Routine Use—Disclosure...

  8. Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, FY 85. Part 14 (Middletown Limousine Sus - North American Carbide Tooling).

    DTIC Science & Technology

    1985-01-01

    Suite � .4 u ~~c s~~e IBo OFFICE SYP.40O 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER O(AN.’-i U0 j if aPPIicabJC) h,~ .. . (City State and ZIP...4 -4 4 4 A 9 o4 m1W "i 0 M () A W I0100 (n .n00 . . . . . . -.j 0 4 44 44 03 :O 󈧇 0-. (N UN001 WL 4 0 -44 4cm ito o-NN1100II0erP-s-40 -4 WC.1- 1󈧄...00 ( 0 I . ) ) 0-6(CO001 2Z00 000 00 c oG c ) 0 00 *00 Ga* c c 00000 to 0 so 0.aa.s4ha 90Omcc01caCO m((0 -101 - 009L - 009- 9 - LA- I 00 -0 00 444 00 44

  9. Excitation-contraction coupling in zebrafish ventricular myocardium is regulated by trans-sarcolemmal Ca2+ influx and sarcoplasmic reticulum Ca2+ release.

    PubMed

    Haustein, Moritz; Hannes, Tobias; Trieschmann, Jan; Verhaegh, Rabea; Köster, Annette; Hescheler, Jürgen; Brockmeier, Konrad; Adelmann, Roland; Khalil, Markus

    2015-01-01

    Zebrafish (Danio rerio) have become a popular model in cardiovascular research mainly due to identification of a large number of mutants with structural defects. In recent years, cardiomyopathies and other diseases influencing contractility of the heart have been studied in zebrafish mutants. However, little is known about the regulation of contractility of the zebrafish heart on a tissue level. The aim of the present study was to elucidate the role of trans-sarcolemmal Ca(2+)-flux and sarcoplasmic reticulum Ca(2+)-release in zebrafish myocardium. Using isometric force measurements of fresh heart slices, we characterised the effects of changes of the extracellular Ca(2+)-concentration, trans-sarcolemmal Ca(2+)-flux via L-type Ca(2+)-channels and Na(+)-Ca(2+)-exchanger, and Ca(2+)-release from the sarcoplasmic reticulum as well as beating frequency and β-adrenergic stimulation on contractility of adult zebrafish myocardium. We found an overall negative force-frequency relationship (FFR). Inhibition of L-type Ca(2+)-channels by verapamil (1 μM) decreased force of contraction to 22 ± 7% compared to baseline (n=4, p<0.05). Ni(2+) was the only substance to prolong relaxation (5 mM, time after peak to 50% relaxation: 73 ± 3 ms vs. 101 ± 8 ms, n=5, p<0.05). Surprisingly though, inhibition of the sarcoplasmic Ca(2+)-release decreased force development to 54 ± 3% in ventricular (n=13, p<0.05) and to 52 ± 8% in atrial myocardium (n=5, p<0.05) suggesting a substantial role of SR Ca(2+)-release in force generation. In line with this finding, we observed significant post pause potentiation after pauses of 5 s (169 ± 7% force compared to baseline, n=8, p<0.05) and 10 s (198 ± 9% force compared to baseline, n=5, p<0.05) and mildly positive lusitropy after β-adrenergic stimulation. In conclusion, force development in adult zebrafish ventricular myocardium requires not only trans-sarcolemmal Ca2+-flux, but also intact sarcoplasmic reticulum Ca(2+)-cycling. In contrast to mammals, FFR is strongly negative in the zebrafish heart. These aspects need to be considered when using zebrafish to model human diseases of myocardial contractility.

  10. Excitation-Contraction Coupling in Zebrafish Ventricular Myocardium Is Regulated by Trans-Sarcolemmal Ca2+ Influx and Sarcoplasmic Reticulum Ca2+ Release

    PubMed Central

    Trieschmann, Jan; Verhaegh, Rabea; Köster, Annette; Hescheler, Jürgen; Brockmeier, Konrad; Adelmann, Roland; Khalil, Markus

    2015-01-01

    Zebrafish (Danio rerio) have become a popular model in cardiovascular research mainly due to identification of a large number of mutants with structural defects. In recent years, cardiomyopathies and other diseases influencing contractility of the heart have been studied in zebrafish mutants. However, little is known about the regulation of contractility of the zebrafish heart on a tissue level. The aim of the present study was to elucidate the role of trans-sarcolemmal Ca2+-flux and sarcoplasmic reticulum Ca2+-release in zebrafish myocardium. Using isometric force measurements of fresh heart slices, we characterised the effects of changes of the extracellular Ca2+-concentration, trans-sarcolemmal Ca2+-flux via L-type Ca2+-channels and Na+-Ca2+-exchanger, and Ca2+-release from the sarcoplasmic reticulum as well as beating frequency and β-adrenergic stimulation on contractility of adult zebrafish myocardium. We found an overall negative force-frequency relationship (FFR). Inhibition of L-type Ca2+-channels by verapamil (1 μM) decreased force of contraction to 22±7% compared to baseline (n=4, p<0.05). Ni2+ was the only substance to prolong relaxation (5 mM, time after peak to 50% relaxation: 73±3 ms vs. 101±8 ms, n=5, p<0.05). Surprisingly though, inhibition of the sarcoplasmic Ca2+-release decreased force development to 54±3% in ventricular (n=13, p<0.05) and to 52±8% in atrial myocardium (n=5, p<0.05) suggesting a substantial role of SR Ca2+-release in force generation. In line with this finding, we observed significant post pause potentiation after pauses of 5 s (169±7% force compared to baseline, n=8, p<0.05) and 10 s (198±9% force compared to baseline, n=5, p<0.05) and mildly positive lusitropy after β-adrenergic stimulation. In conclusion, force development in adult zebrafish ventricular myocardium requires not only trans-sarcolemmal Ca2+-flux, but also intact sarcoplasmic reticulum Ca2+-cycling. In contrast to mammals, FFR is strongly negative in the zebrafish heart. These aspects need to be considered when using zebrafish to model human diseases of myocardial contractility. PMID:25938412

  11. Functional desensitization to isoproterenol without reducing cAMP production in canine failing cardiocytes.

    PubMed

    Laurent, C E; Cardinal, R; Rousseau, G; Vermeulen, M; Bouchard, C; Wilkinson, M; Armour, J A; Bouvier, M

    2001-02-01

    To corroborate alterations in the functional responses to beta-adrenergic receptor (beta-AR) stimulation with changes in beta-AR signaling in failing cardiomyocytes, contractile and L-type Ca(2+) current responses to isoproterenol along with stimulated cAMP generation were compared among cardiomyocytes isolated from canines with tachycardia-induced heart failure or healthy hearts. The magnitude of shortening of failing cardiomyocytes was significantly depressed (by 22 +/- 4.4%) under basal conditions, and the maximal response to isoproterenol was significantly reduced (by 45 +/- 18%). Similar results were obtained when the responses in the rate of contraction and rate of relaxation to isoproterenol were considered. The L-type Ca(2+) current amplitude measured in failing cardiomyocytes under basal conditions was unchanged, but the responses to isoproterenol were significantly reduced compared with healthy cells. Isoproterenol-stimulated cAMP generation was similar in sarcolemmal membranes derived from the homogenates of failing (45 +/- 6.8) and healthy cardiomyocytes (52 +/- 8.5 pmol cAMP. mg protein(-1). min(-1)). However, stimulated cAMP generation was found to be significantly reduced when the membranes were derived from the homogenates of whole tissue (failing: 67 +/- 8.1 vs. healthy: 140 +/- 27.8 pmol cAMP. mg protein(-1). min(-1)). Total beta-AR density was not reduced in membranes derived from either whole tissue or isolated cardiomyocyte homogenates, but the beta(1)/beta(2) ratio was significantly reduced in the former (failing: 45/55 vs. healthy: 72/28) without being altered in the latter (failing: 72/28, healthy: 77/23). We thus conclude that, in tachycardia-induced heart failure, reduction in the functional responses of isolated cardiomyocytes to beta-AR stimulation may be attributed to alterations in the excitation-contraction machinery rather than to limitation of cAMP generation.

  12. Zeno subspace in quantum-walk dynamics

    NASA Astrophysics Data System (ADS)

    Chandrashekar, C. M.

    2010-11-01

    We investigate discrete-time quantum-walk evolution under the influence of periodic measurements in position subspace. The undisturbed survival probability of the particle at the position subspace P(0,t) is compared with the survival probability after frequent (n) measurements at interval τ=t/n, P(0,τ)n. We show that P(0,τ)n>P(0,t) leads to the quantum Zeno effect in position subspace when a parameter θ in the quantum coin operations and frequency of measurements is greater than the critical value, θ>θc and n>nc. This Zeno effect in the subspace preserves the dynamics in coin Hilbert space of the walk dynamics and has the potential to play a significant role in quantum tasks such as preserving the quantum state of the particle at any particular position, and to understand the Zeno dynamics in a multidimensional system that is highly transient in nature.

  13. Spatial nonuniformity of contraction causes arrhythmogenic Ca2+ waves in rat cardiac muscle.

    PubMed

    Ter Keurs, Henk E D J; Wakayama, Yuji; Miura, Masahito; Stuyvers, Bruno D; Boyden, Penelope A; Landesberg, Amir

    2005-06-01

    Landesberg and Sideman's four state model of the cardiac cross-bridge (XB) hypothesizes a feedback of force development to Ca(2+) binding by troponin C (TnC). We have further modeled this behavior and observed that the force (F)-Ca(2+) relationship as well as the F-sarcomere length (SL) relationship and the time course of F and Ca(2+) transients in cardiac muscle can be reproduced faithfully by a single effect of F on deformation of the TnC-Ca complex and, thereby, on the dissociation rate of Ca(2+). Furthermore, this feedback predicts that rapid decline of F in the activated sarcomere causes release of Ca(2+) from TnC-Ca(2+), which is sufficient to initiate arrhythmogenic Ca(2+) release from the sarcoplasmic reticulum (SR). This work investigated the initiation of Ca(2+) waves underlying triggered propagated contractions (TPCs) in rat cardiac trabeculae under conditions that simulate functional nonuniformity caused by mechanical or ischemic local damage of the myocardium. A mechanical discontinuity along the trabeculae was created by exposing the preparation to a small constant flow jet of solution that reduces excitation-contraction coupling in myocytes within that segment. Force was measured, and SL as well as [Ca(2+)](i) were measured regionally. When the jet contained caffeine, 2,3-butanedione monoxime or low-[Ca(2+)], muscle-twitch F decreased and the sarcomeres in the exposed segment were stretched by shortening the normal regions outside the jet. During relaxation, the sarcomeres in the exposed segment shortened rapidly. Short trains of stimulation at 2.5 Hz reproducibly caused Ca(2+) waves to rise from the borders exposed to the jet. Ca(2+) waves started during F relaxation of the last stimulated twitch and propagated into segments both inside and outside of the jet. Arrhythmias, in the form of nondriven rhythmic activity, were triggered when the amplitude of the Ca(2+) wave increased by raising [Ca(2+)](o). The arrhythmias disappeared when the muscle uniformity was restored by turning the jet off. These results show that nonuniform contraction can cause Ca(2+) waves underlying TPCs, and suggest that Ca(2+) dissociated from myofilaments plays an important role in the initiation of arrhythmogenic Ca(2+) waves.

  14. Structure and spectroscopic properties of the dimeric copper(I) N-heterocyclic carbene complex [Cu₂(CNC(t-Bu))₂](PF₆)₂.

    PubMed

    Riener, Korbinian; Pöthig, Alexander; Cokoja, Mirza; Herrmann, Wolfgang A; Kühn, Fritz E

    2015-08-01

    In recent years, the use of copper N-heterocyclic carbene (NHC) complexes has expanded to fields besides catalysis, namely medicinal chemistry and luminescence applications. In the latter case, multinuclear copper NHC compounds have attracted interest, however, the number of these complexes in the literature is still quite limited. Bis[μ-1,3-bis(3-tert-butylimidazolin-2-yliden-1-yl)pyridine]-1κ(4)C(2),N:N,C(2');2κ(4)C(2),N:N,C(2')-dicopper(I) bis(hexafluoridophosphate), [Cu2(C19H25N5)2](PF6)2, is a dimeric copper(I) complex bridged by two CNC, i.e. bis(N-heterocyclic carbene)pyridine, ligands. Each Cu(I) atom is almost linearly coordinated by two NHC ligands and interactions are observed between the pyridine N atoms and the metal centres, while no cuprophilic interactions were observed. Very strong absorption bands are evident in the UV-Vis spectrum at 236 and 274 nm, and an emission band is observed at 450 nm. The reported complex is a new example of a multinuclear copper NHC complex and a member of a compound class which has only rarely been reported.

  15. Manual asymmetry in older adults on a complex coincidence-anticipation task.

    PubMed

    Rodrigues, Paula Cristina Dos Santos; Silva, João Miguel Carvalho da; Barreiros, João Manuel Pardal; Vasconcelos, Maria Olga Fernandes

    2018-04-20

    Age-related asymmetrical functional decline was tested in a sample of 57 right-handed volunteers between 65 and 85 years of age. Participants performed a complex coincidence-anticipation (CA) task with both preferred and non-preferred hands. Results demonstrated that the proficiency of a complex CA task was similar for the 2 age groups, but different for the 2 hands. The non-preferred hand was more proficient for temporal accuracy but not for response timing, which was similar for both hands. Moreover, the lack of interaction between age and hand both in response timing and response accuracy reveal symmetric performance across ages.

  16. MG53 participates in ischaemic postconditioning through the RISK signalling pathway

    PubMed Central

    Zhang, Yan; Lv, Fengxiang; Jin, Li; Peng, Wei; Song, Ruisheng; Ma, Jianjie; Cao, Chun-Mei; Xiao, Rui-Ping

    2011-01-01

    Aims Recent studies show that ischaemic postconditioning (PostC), similar to the well-established ischaemic preconditioning (IPC), confers cardioprotection against ischaemia/reperfusion (IR) injury, and both IPC and PostC can activate the reperfusion injury salvage kinase (RISK) pathway and the survivor activating factor enhancement (SAFE) pathway. PostC is clinically more attractive because of its therapeutic application at the predictable onset of reperfusion. Our previous studies have demonstrated that MG53 is a primary component of the IPC machinery. Here, we investigated the potential role of MG53 in PostC-mediated myocardial protection and explored the underlying mechanism. Methods and results Using Langendorff perfusion, we investigated IR injury in wild-type (wt) and MG53-deficient (mg53−/−) mouse hearts with or without PostC. IR-induced myocardial damage was markedly exacerbated in mg53−/− hearts compared with wt controls. PostC protected wt hearts against IR-induced myocardial infarction, myocyte necrosis, and apoptosis, but failed to protect mg53−/− hearts. The loss of PostC protection in mg53−/− hearts was attributed to selectively impaired PostC-activated RISK signalling. Mechanistically, MG53 is required for the interaction between caveolin 3 (CaV3) and the p85 subunit of phosphoinositide 3-kinase (p85-PI3K) and PostC-mediated activation of the RISK pathway. Importantly, a structure–function study revealed that the MG53 tripartite motif (TRIM) domain (aa1–284) physically interacted with CaV3 but not p85-PI3K, whereas the MG53 SPRY domain (aa285–477) interacted with p85-PI3K but not CaV3, indicating that MG53 binds to CaV3 and p85 at its N- and C-terminus, respectively. Conclusions We conclude that MG53 participates in PostC-mediated cardioprotection largely through tethering CaV3 and PI3K and subsequent activation of the RISK pathway. PMID:21285295

  17. 1-[1-(4-Chloro-phen-yl)ethyl-idene]carbono-hydrazide.

    PubMed

    Du, Lingyun; Du, Lei; Wang, Shuhao

    2009-08-12

    The mol-ecular skeleton of the title mol-ecule, C(9)H(11)ClN(4)O, is essentially planar, the dihedral angle between the ring and the and N/N/C plane being 6.7 (3)°. In the crystal, inter-molecular N-H⋯O and N-H⋯N hydrogen bonds link the mol-ecules into ribbons propagated along [010].

  18. Phasic Contractions of the Mouse Vagina and Cervix at Different Phases of the Estrus Cycle and during Late Pregnancy

    PubMed Central

    Gravina, Fernanda S.; van Helden, Dirk F.; Kerr, Karen P.; de Oliveira, Ramatis B.; Jobling, Phillip

    2014-01-01

    Background/Aims The pacemaker mechanisms activating phasic contractions of vaginal and cervical smooth muscle remain poorly understood. Here, we investigate properties of pacemaking in vaginal and cervical tissues by determining whether: 1) functional pacemaking is dependent on the phase of the estrus cycle or pregnancy; 2) pacemaking involves Ca2+ release from sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) -dependent intracellular Ca2+ stores; and 3) c-Kit and/or vimentin immunoreactive ICs have a role in pacemaking. Methodology/Principal Findings Vaginal and cervical contractions were measured in vitro, as was the distribution of c-Kit and vimentin positive interstitial cells (ICs). Cervical smooth muscle was spontaneously active in estrus and metestrus but quiescent during proestrus and diestrus. Vaginal smooth muscle was normally quiescent but exhibited phasic contractions in the presence of oxytocin or the K+ channel blocker tetraethylammonium (TEA) chloride. Spontaneous contractions in the cervix and TEA-induced phasic contractions in the vagina persisted in the presence of cyclopiazonic acid (CPA), a blocker of the SERCA that refills intracellular SR Ca2+ stores, but were inhibited in low Ca2+ solution or in the presence of nifedipine, an inhibitor of L-type Ca2+channels. ICs were found in small numbers in the mouse cervix but not in the vagina. Conclusions/Significance Cervical smooth muscle strips taken from mice in estrus, metestrus or late pregnancy were generally spontaneously active. Vaginal smooth muscle strips were normally quiescent but could be induced to exhibit phasic contractions independent on phase of the estrus cycle or late pregnancy. Spontaneous cervical or TEA-induced vaginal phasic contractions were not mediated by ICs or intracellular Ca2+ stores. Given that vaginal smooth muscle is normally quiescent then it is likely that increases in hormones such as oxytocin, as might occur through sexual stimulation, enhance the effectiveness of such pacemaking until phasic contractile activity emerges. PMID:25337931

  19. Phasic contractions of the mouse vagina and cervix at different phases of the estrus cycle and during late pregnancy.

    PubMed

    Gravina, Fernanda S; van Helden, Dirk F; Kerr, Karen P; de Oliveira, Ramatis B; Jobling, Phillip

    2014-01-01

    The pacemaker mechanisms activating phasic contractions of vaginal and cervical smooth muscle remain poorly understood. Here, we investigate properties of pacemaking in vaginal and cervical tissues by determining whether: 1) functional pacemaking is dependent on the phase of the estrus cycle or pregnancy; 2) pacemaking involves Ca2+ release from sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) -dependent intracellular Ca2+ stores; and 3) c-Kit and/or vimentin immunoreactive ICs have a role in pacemaking. Vaginal and cervical contractions were measured in vitro, as was the distribution of c-Kit and vimentin positive interstitial cells (ICs). Cervical smooth muscle was spontaneously active in estrus and metestrus but quiescent during proestrus and diestrus. Vaginal smooth muscle was normally quiescent but exhibited phasic contractions in the presence of oxytocin or the K+ channel blocker tetraethylammonium (TEA) chloride. Spontaneous contractions in the cervix and TEA-induced phasic contractions in the vagina persisted in the presence of cyclopiazonic acid (CPA), a blocker of the SERCA that refills intracellular SR Ca2+ stores, but were inhibited in low Ca2+ solution or in the presence of nifedipine, an inhibitor of L-type Ca2+channels. ICs were found in small numbers in the mouse cervix but not in the vagina. Cervical smooth muscle strips taken from mice in estrus, metestrus or late pregnancy were generally spontaneously active. Vaginal smooth muscle strips were normally quiescent but could be induced to exhibit phasic contractions independent on phase of the estrus cycle or late pregnancy. Spontaneous cervical or TEA-induced vaginal phasic contractions were not mediated by ICs or intracellular Ca2+ stores. Given that vaginal smooth muscle is normally quiescent then it is likely that increases in hormones such as oxytocin, as might occur through sexual stimulation, enhance the effectiveness of such pacemaking until phasic contractile activity emerges.

  20. Determination of ragaglitazar, a novel dual acting peroxisome proliferator-activated receptor (PPAR) alpha and -gamma agonist, in human plasma by high-performance liquid chromatography coupled with tandem mass spectrometry.

    PubMed

    Andersen, Michael P; Nielsen, Karin K

    2003-05-05

    A sensitive and specific LC/MS/MS method has been developed and validated for determination of ragaglitazar (NNC 61-0029 or DRF 2725) in human plasma. After solid-phase extraction (SPEC((R)) PLUS C(8)) of plasma, separation was performed on a Symmetry Shield RP8 column (mobile phase: acetonitrile: 10 mM ammonium acetate, pH 5.6 (40:60 v/v)). Two ranges were validated having LLOQs of either 0.500 or 100 ng/ml and linearity up to either 500 or 50000 ng/ml. The intra-assay precision and accuracy were 1.1% to 15.7% and 85.8% to 118.2% (range 0.500-500 ng/ml) and 2.0% to 8.8% and 92.9% to 104.8% (range 100-50000 ng/ml). The method was applied for determination of ragaglitazar in plasma from phase 1 and 2 clinical studies.

  1. Nitroxyl Improves Cellular Heart Function by Directly Enhancing Cardiac Sarcoplasmic Reticulum Ca2+ Cycling

    PubMed Central

    Tocchetti, Carlo G.; Wang, Wang; Froehlich, Jeffrey P.; Huke, Sabine; Aon, Miguel A.; Wilson, Gerald M.; Benedetto, Giulietta Di; O’Rourke, Brian; Gao, Wei Dong; Wink, David A.; Toscano, John P.; Zaccolo, Manuela; Bers, Donald M.; Valdivia, Hector H.; Cheng, Heping; Kass, David A.; Paolocci, Nazareno

    2009-01-01

    Heart failure remains a leading cause of morbidity and mortality worldwide. Although depressed pump function is common, development of effective therapies to stimulate contraction has proven difficult. This is thought to be attributable to their frequent reliance on cAMP stimulation to increase activator Ca2+. A potential alternative is nitroxyl (HNO), the 1-electron reduction product of nitric oxide (NO) that improves contraction and relaxation in normal and failing hearts in vivo. The mechanism for myocyte effects remains unknown. Here, we show that this activity results from a direct interaction of HNO with the sarcoplasmic reticulum Ca2+ pump and the ryanodine receptor 2, leading to increased Ca2+ uptake and release from the sarcoplasmic reticulum. HNO increases the open probability of isolated ryanodine-sensitive Ca2+-release channels and accelerates Ca2+ reuptake into isolated sarcoplasmic reticulum by stimulating ATP-dependent Ca2+ transport. Contraction improves with no net rise in diastolic calcium. These changes are not induced by NO, are fully reversible by addition of reducing agents (redox sensitive), and independent of both cAMP/protein kinase A and cGMP/protein kinase G signaling. Rather, the data support HNO/thiolate interactions that enhance the activity of intracellular Ca2+ cycling proteins. These findings suggest HNO donors are attractive candidates for the pharmacological treatment of heart failure. PMID:17138943

  2. [14C]-beta-phenethylamine, its distribution after administration by various routes to cats, and the effects of monoamine oxidase inhibitors.

    PubMed Central

    Garcha, G.; Imrie, P. R.; Marley, E.; Thomas, D. V.

    1985-01-01

    [14C]-beta-phenethylamine [( 14C]-PEA) was instilled intragastrically, intraduodenally (i.d.) or infused into the portal vein or femoral artery of cats, anaesthetized with chloralose, to investigate its distribution in the body. [14C]-PEA and phenylacetic acid (PAA) accounted for approximately 85% of radioactivity recovered in blood from control cats or those pretreated with deprenyl or mebanazine. Progressively greater portal venous (PV), cranial mesenteric arterial (CMA) and PV-CMA concentrations of PEA and PAA were observed with increase in amount of PEA instilled intraduodenally (i.d.); PAA predominated over PEA, more so in CMA than PV blood. Radioactivity was not recovered from blood following intragastric instillation of PEA. When histamine 1.7 mumol kg-1, i.d., was combined with PEA 1.7 mumol kg-1, i.d., or tyramine 8.5 mumol kg-1, i.d., was combined with PEA 8.5 mumol kg-1, i.d., PV-CMA values for PEA were significantly augmented. Arterial concentrations of PEA were increased 3.5 to 5 fold compared to controls by pretreatment with mebanazine or deprenyl plus clorgyline; arterial concentrations of PAA were reduced. PEA blood concentrations were not significantly altered by clorgyline or deprenyl pretreatment. Infusion of PEA 680, 1020 or 1360 nmol kg-1 min-1 for 20 min into the portal vein raised blood pressure 60 to 100 mmHg (at a PEA concentration of ca, 2 nmol ml-1) but lacked effect on the nictitating membrane despite peak arterial PEA concentrations of 20 nmol ml-1; in cats pretreated with mebanazine or clorgyline plus deprenyl, half-maximum contraction of the nictitating membrane occurred with arterial PEA concentrations of 4.8 to 9 nmol ml-1. In cats pretreated with mebanazine or deprenyl plus clorgyline, half maximum contraction of the nictitating membrane was elicited also by intraduodenal PEA 8.5 mumol kg-1 at arterial PEA concentrations of ca. 2 nmol ml-1, despite lack of effect of PEA 17 mumol kg-1, i.d., in control cats with a peak arterial PEA concentration of 1.8 nmol ml-1. [14C]-PEA and PAA were recovered from liver, kidney, distal small intestine, lung, arterial vessel walls, skeletal muscle, brain, foetus and amniotic liquor, after PEA instilled i.d., overall concentration of PEA exceeding that of PAA except in the kidney. The combined amount of PEA and PAA in kidney was 7 to 20 fold that in other tissues. PEA content of tissues was significantly elevated and that of PAA diminished by pretreatment with deprenyl plus clorgyline, and to a lesser extent after mebanazine. PMID:4075021

  3. Annual Report of the National Science Foundation on Contract NSF-C414 Task III July 1966 through June 1967.

    ERIC Educational Resources Information Center

    American Chemical Society, Columbus, OH. Chemical Abstracts Service.

    This Annual Report describes in detail the work performed during the first year of Task III of Contract NSF-C414 and the present status of Task III work. The programs and achievements described constitute the first significant efforts to develop a user-oriented, cooperative program between major secondary scientific and technical information…

  4. 17 CFR 250.85 - Service, sales, and construction by registered holding companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Service, sales, and... ACT OF 1935 Service, Sales and Construction Contracts § 250.85 Service, sales, and construction by...; or (c) Such transaction consists of performance of a contract made before August 26, 1935, for the...

  5. 17 CFR 250.85 - Service, sales, and construction by registered holding companies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Service, sales, and... ACT OF 1935 Service, Sales and Construction Contracts § 250.85 Service, sales, and construction by...; or (c) Such transaction consists of performance of a contract made before August 26, 1935, for the...

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Comar, C.L.; Lengemann, F.W.; Wasserman, R.H. et al

    Research activities during the past 6 years are reviewed. Results are reported for recent studies on adaptation to increased dietary Ca by dairy cows as a factor in the reduction of Sr/sup 90/ content of milk; the testing of a theoretical model of alkaline earth absorption in rats by a comparison of biological discrimination among Ca/sup 47/, Sr/sup 85/, and Ba/sup 133/ in the presence of glucose, lactose, and lysine; the effects of lactose on the intestinal absorption of Ca in rats; a comparison of the ileal absorption of Ca/ sup 47/ and Sr/sup 85/ by rats from solutions withmore » high and low concentrations of stable Ca; determinatione of the Ca, Mg, and total alkaline earth content in mucosal tissue and plasma of normally fed rats, fasted rats, and rats fed a lactose solution; an investigation of non-exchangeable Ca compartments in the plasma of sheep; the effect of lactose and vitamin D on calcification in the rachitic chick; the metabolism and milk content of I/sup 131/ of dairy cows after long-term daily administration of I/sup 131/; the absorption of Fe/sup 59/ in sheep; the development of a method for the estimation of parasitic blood loss in sheep by whole-body counting of Fe/sup 59/ retention; the development of a method for the simultaneous measurement of erythrocyte and plasma volume in sheep using Fe/sup 59/ as a tracer; the concentration of Na/sup 22/, Cl/sup 36/, and C/sup 14/ inulin in rat kidney and counter-current mechanisms for the production of concentrated urine in mammals; the effects of diuretics on the distribution of Na/ sup 22/, Fe/sup 59/-labeled erythrocytes, and I/sup 131/labeled albumin in rat kidneys; the effects of thiamine on nervous response to ultraviolet radiation in frogs and lobsters; the effects of gamma radiation on reproductive capabilities of young male rabbits; and an evaluation of the contamination of the food chain by fallout fission products, with emphasis on Sr/sup 90/, Cs/sup 137/, and I/sup 131/ intake from total diet and individual food items. A list is included of publications resulting from research conducted under this contract. (C.H.)« less

  7. Rate modulation of human anconeus motor units during high-intensity dynamic elbow extensions.

    PubMed

    Cowling, Brianna L; Harwood, Brad; Copithorne, David B; Rice, Charles L

    2016-08-01

    Investigations of high-intensity isometric fatiguing protocols report decreases in motor unit firing rates (MUFRs), but little is known regarding changes in MUFRs following fatigue induced by high-intensity dynamic contractions. Our purpose was to evaluate MUFRs of the anconeus (an accessory elbow extensor) and elbow extension power production as a function of time to task failure (TTF) during high-velocity fatiguing concentric contractions against a moderately heavy resistance. Fine-wire intramuscular electrode pairs were inserted into the anconeus to record MUs in 12 male participants (25 ± 3 yr), over repeated sessions on separate days. MUs were tracked throughout a three-stage, varying load dynamic elbow extension protocol designed to extend the task duration for >1 min thereby inducing substantial fatigue. Mean MUFRs and peak power were calculated for three relative time ranges: 0-15% TTF (beginning), 45-60% TTF (middle) and 85-100% TTF (end). Mean duration of the overall fatigue protocol was ∼80 s. Following the protocol, isometric maximum voluntary contraction (MVC), highest velocity at 35% MVC load, and peak power decreased 37, 60, and 64% compared with baseline, respectively. Data from 20 anconeus MUs tracked successfully throughout the protocol indicated a reduction in MUFRs in relation to power loss from 36 Hz/160 W (0-15% TTF) to 28 Hz/97 W (45-60% TTF) to 23 Hz/43 W (85-100% TTF). During these high-intensity maximal effort concentric contractions, anconeus MUFRs decreased substantially (>35%). Although the absolute MUFRs were higher in the present study than those reported previously for other muscles during sustained high-intensity isometric tasks, the relative decrease in MUFRs was similar between the two tasks. Copyright © 2016 the American Physiological Society.

  8. Calcium sensitization in human esophageal muscle: role for RhoA kinase in maintenance of lower esophageal sphincter tone.

    PubMed

    Sims, Stephen M; Chrones, Tom; Preiksaitis, Harold G

    2008-10-01

    A rise in intracellular-free calcium ([Ca(2+)](i)) concentration is important for initiating contraction of smooth muscles, and Ca(2+) sensitization involving RhoA kinase can sustain tension. We previously found that [Ca(2+)](i) was comparable in cells from the esophageal body (EB) and lower esophageal sphincter (LES) muscles, despite the fact that the LES maintains resting tone. We hypothesized that Ca(2+) sensitization contributes to contraction in human esophageal muscle. Tension and [Ca(2+)](i) were measured simultaneously in intact human EB and LES muscles using the ratiometric Ca(2+)-sensitive dye fura-2. Spontaneous oscillations in EB muscle tension were associated with transient elevations of [Ca(2+)](i). Carbachol caused a large increase in tension, compared with spontaneous oscillations, although the rise of [Ca(2+)](i) was similar, suggesting Ca(2+) sensitization. The RhoA-kinase blockers (R)-(+)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride monohydrate (Y-27632) and 1-(5-isoquinolinesulfonyl)-homopiperazine hydrochloride (HA-1077) reduced carbachol- and nerve-evoked contraction of the EB, accompanied by smaller reduction in the rise of [Ca(2+)](i). Protein kinase C inhibitors reduced force to a lesser extent. RhoA-kinase blockers caused concentration-dependent reduction of tension in spontaneously contracted LES muscles. Moreover, RhoA-kinase blockers reduced intrinsic nerve-evoked and carbachol-evoked contraction. However, there was no effect on nerve- or nitric oxide-mediated relaxation of LES. Ca(2+) sensitization mediated by the RhoA-kinase pathway has an important role in contraction of human EB muscles and LES tonic contraction, a feature not previously recognized.

  9. Glucose-6-phosphate dehydrogenase is a regulator of vascular smooth muscle contraction.

    PubMed

    Gupte, Rakhee S; Ata, Hirotaka; Rawat, Dhawjbahadur; Abe, Madoka; Taylor, Mark S; Ochi, Rikuo; Gupte, Sachin A

    2011-02-15

    Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme in the pentose phosphate pathway and a major source of nicotinamide adenine dinucleotide phosphate reduced (NADPH), which regulates numerous enzymatic (including glutathione reductase and NADPH oxidase that, respectively, generates reduced glutathione and reactive oxygen species) reactions involved in various cellular actions, yet its physiological function is seldom investigated. We, however, recently showed that inhibiting G6PD causes precontracted coronary artery (CA) to relax in an endothelium-derived relaxing factor- and second messenger-independent manner. Here we assessed the role of G6PD in regulating CA contractility. Treating bovine CAs for 20 min with potassium chloride (KCl; 30 mM), amphotericin B (50 μM), or U46619 (100 nM) significantly (p < 0.05) increased both G6PD activity and glucose flux through the pentose phosphate pathway. The effect was Ca(2+) independent, and there was a corresponding increase in protein kinase C (PKC) activity. Activation of G6PD by KCl was blocked by the PKCδ inhibitor rottlerin (10 μM) or by knocking down PKCδ expression using siRNA. Phorbol 12, 13-dibutyrate (10 μM), a PKC activator, significantly increased G6PD phosphorylation and activity, whereas single (S210A, T266A) and double (S210A/T266A) mutations at sites flanking the G6PD active site significantly inhibited phosphorylation, shifted the isoelectric point, and reduced enzyme activity. Knocking down G6PD decreased NADPH and reactive oxygen species generation, and reduced KCl-evoked increases in [Ca(2+)](i) and myosin light chain phosphorylation, thereby reducing CA contractility. Similarly, aortas from G6PD-deficient mice developed less KCl/phorbol 12, 13-dibutyrate-evoked force than those from their wild-type littermates. Conversely, overexpression of G6PD augmented KCl-evoked increases in [Ca(2+)](i), thereby augmenting CA contraction. Our findings demonstrate that G6PD activity and NADPH is increased in activated CA in a PKCδ-dependent manner and that G6PD modulates Ca(2+) entry and CA contractions evoked by membrane depolarization.

  10. Distinct effects of CGRP on typical and atypical smooth muscle cells involved in generating spontaneous contractions in the mouse renal pelvis

    PubMed Central

    Hashitani, Hikaru; Lang, Richard J; Mitsui, Retsu; Mabuchi, Yoshio; Suzuki, Hikaru

    2009-01-01

    Background and purpose: We investigated the cellular mechanisms underlying spontaneous contractions in the mouse renal pelvis, regulated by calcitonin gene-related peptide (CGRP). Experimental approach: Spontaneous contractions, action potentials and Ca2+ transients in typical and atypical smooth muscle cells (TSMCs and ATSMCs) within the renal pelvis wall were recorded separately using tension and intracellular microelectrode recording techniques and Fluo-4 Ca2+ imaging. Immunohistochemical and electron microscopic studies were also carried out. Key results: Bundles of CGRP containing transient receptor potential cation channel, subfamily V, member 1-positive sensory nerves were situated near both TSMCs and ATSMCs. Nerve stimulation reduced the frequency but augmented the amplitude and duration of spontaneous phasic contractions, action potentials and Ca2+ transients in TSMCs. CGRP and agents increasing internal cyclic adenosine monophosphate (cAMP) mimicked the nerve-mediated modulation of TSMC activity and suppressed ATSMCs Ca2+ transients. Membrane hyperpolarization induced by CGRP or cAMP stimulators was blocked by glibenclamide, while their negative chronotropic effects were less affected. Glibenclamide enhanced TSMC Ca2+ transients but inhibited ATSMC Ca2+ transients, while both 5-hydroxydecanoate and diazoxide, a blocker and opener of mitochondrial ATP-sensitive K+ channels, respectively, reduced the Ca2+ transient frequency in both TSMCs and ATSMCs. Inhibition of mitochondrial function blocked ATSMCs Ca2+ transients and inhibited spontaneous excitation of TSMCs. Conclusions and implications: The negative chronotropic effects of CGRP result primarily from suppression of ATSMC Ca2+ transients rather than opening of plasmalemmal ATP-sensitive K+ channels in TSMCs. The positive inotropic effects of CGRP may derive from activation of TSMC L-type Ca2+ channels. Mitochondrial Ca2+ handling in ATSMCs also plays a critical role in generating Ca2+ transients. PMID:20050194

  11. Fluorescent Protein-Based Ca2+ Sensor Reveals Global, Divalent Cation-Dependent Conformational Changes in Cardiac Troponin C.

    PubMed

    Badr, Myriam A; Pinto, Jose R; Davidson, Michael W; Chase, P Bryant

    2016-01-01

    Cardiac troponin C (cTnC) is a key effector in cardiac muscle excitation-contraction coupling as the Ca2+ sensing subunit responsible for controlling contraction. In this study, we generated several FRET sensors for divalent cations based on cTnC flanked by a donor fluorescent protein (CFP) and an acceptor fluorescent protein (YFP). The sensors report Ca2+ and Mg2+ binding, and relay global structural information about the structural relationship between cTnC's N- and C-domains. The sensors were first characterized using end point titrations to decipher the response to Ca2+ binding in the presence or absence of Mg2+. The sensor that exhibited the largest responses in end point titrations, CTV-TnC, (Cerulean, TnC, and Venus) was characterized more extensively. Most of the divalent cation-dependent FRET signal originates from the high affinity C-terminal EF hands. CTV-TnC reconstitutes into skinned fiber preparations indicating proper assembly of troponin complex, with only ~0.2 pCa unit rightward shift of Ca2+-sensitive force development compared to WT-cTnC. Affinity of CTV-TnC for divalent cations is in agreement with known values for WT-cTnC. Analytical ultracentrifugation indicates that CTV-TnC undergoes compaction as divalent cations bind. C-terminal sites induce ion-specific (Ca2+ versus Mg2+) conformational changes in cTnC. Our data also provide support for the presence of additional, non-EF-hand sites on cTnC for Mg2+ binding. In conclusion, we successfully generated a novel FRET-Ca2+ sensor based on full length cTnC with a variety of cellular applications. Our sensor reveals global structural information about cTnC upon divalent cation binding.

  12. The CINCS (Commanders-in-Chief) and the Acquisition Process

    DTIC Science & Technology

    1988-09-01

    ELEMENT I PROJECT NO. TASK NO. ACCESSION NO. Washington, DC 20301 T -AO-461 WORK UNIT 11. TITLE (Inokde Seoewhly Clasifloetlon) THE CINCS AND THE ACQUISITION...Herschel Kanter Leonard Wainstein Rachel Kaganoff Barry Pavel September 1988 IDA INSTITUTE FOR DEFENSE ANALYSES Contract MDA 903 84 C 0031 Task T -AO-461...3 PREFACE This task was undertaken as part of Task T -AO-461, "Special Studies of Critical Defense Issues," Contract Number MDA 903 84 C 0031. Its

  13. Effects of PPADS and suramin on contractions and cytoplasmic Ca2+ changes evoked by AP4A, ATP and alpha, beta-methylene ATP in guinea-pig urinary bladder.

    PubMed Central

    Usune, S.; Katsuragi, T.; Furukawa, T.

    1996-01-01

    1. The contraction and intracellular Ca2+ change evoked by diadenosine tetraphosphate (AP4A) were studied in the outer longitudinal muscle of the guinea-pig urinary bladder and compared with those evoked by ATP and alpha, beta-methylene ATP (a P2-purinoceptor agonist). 2. AP4A, ATP and alpha, beta-methylene ATP produced concentration-dependent transient contractions. These contractions were inhibited by PPADS (pyridoralphosphate-6-azophenyl- 2'-4'-disulphonic acid), 0.3- 30 microM, a P2x-purinoceptor antagonist, and suramin, 1-300 microM, a P2-purinoceptor antagonist in a concentration-dependent manner. From Schild plot analysis, the apparent pA2 values for PPADS for contractions evoked by AP4A, ATP and alpha, beta-methylene ATP were 6.86, 6.56, 6.74, and those for suramin were 6.01, 4.59 and 5.12, respectively; the Schild slopes for PPADS were 1.07, 1.14 and 1.06, and, those for suramin 0.75, 1.05 and 1.16, respectively. 3. AP4A (10 microM) and ATP (100 microM) failed to elicit any contraction of the tissue after a desensitization produced by repeated application of alpha, beta-methylene ATP (1 microM). 4. In fluorescence experiments with fura-2, the increases in [Ca2+]i and contraction evoked by AP4A were suppressed by suramin and nifedipine, an L-type Ca2+ channel blocker. 5. These findings suggest that P2x-purinoceptors, which are more sensitive to PPADS than suramin, exist on the outer longitudinal muscles of guinea-pig urinary bladder, and that the AP4A-evoked contraction results from Ca2+ influx. PMID:8646416

  14. Canada's northern food subsidy Nutrition North Canada: a comprehensive program evaluation.

    PubMed

    Galloway, Tracey

    2017-01-01

    Nutrition North Canada (NNC) is a retail subsidy program implemented in 2012 and designed to reduce the cost of nutritious food for residents living in Canada's remote, northern communities. The present study evaluates the extent to which NNC provides access to perishable, nutritious food for residents of remote northern communities. Program documents, including fiscal and food cost reports for the period 2011-2015, retailer compliance reports, audits of the program, and the program's performance measurement strategy are examined for evidence that the subsidy is meeting its objectives in a manner both comprehensive and equitable across regions and communities. NNC lacks price caps or other means of ensuring food is affordable and equitably priced in communities. Gaps in food cost reporting constrain the program's accountability. From 2011-15, no adjustments were made to community eligibility, subsidy rates, or the list of eligible foods in response to information provided by community members, critics, the Auditor General of Canada, and the program's own Advisory Board. Measures to increase program accountability, such as increasing subsidy information on point-of-sale receipts, make NNC more visible but do nothing to address underlying accountability issues Conclusions: The current structure and regulatory framework of NNC are insufficient to ensure the program meets its goal. Both the volume and cost of nutritious food delivered to communities is highly variable and dependent on factors such as retailers' pricing practices, over which the program has no control. It may be necessary to consider alternative forms of policy in order to produce sustainable improvements to food security in remote, northern communities.

  15. Caffeine and length dependence of staircase potentiation in skeletal muscle.

    PubMed

    Rassier, D E; Tubman, L A; MacIntosh, B R

    1998-01-01

    Skeletal muscle sensitivity to Ca2+ is greater at long lengths, and this results in an optimal length for twitch contractions that is longer than optimal length for tetanic contractions. Caffeine abolishes this length dependence of Ca2+ sensitivity. Muscle length (ML) also affects the degree of staircase potentiation. Since staircase potentiation is apparently caused by an increased Ca2+ sensitivity of the myofilaments, we tested the hypothesis that caffeine depresses the length dependence of staircase potentiation. In situ isometric twitch contractions of rat gastrocnemius muscle before and after 10 s of 10-Hz stimulation were analyzed at seven different lengths to evaluate the length dependence of staircase potentiation. In the absence of caffeine, length dependence of Ca2+ sensitivity was observed, and the degree of potentiation after 10-Hz stimulation showed a linear decrease with increased length (DT = 1.47 - 0.05 ML, r2 = 0.95, where DT is developed tension). Length dependence of Ca2+ sensitivity was decreased by caffeine when caffeine was administered in amounts estimated to result in 0.5 and 0.75 mM concentrations. Furthermore, the negative slope of the relationship between staircase potentiation and muscle length was diminished at the lower caffeine dose, and the slope was not different from zero after the higher dose (DT = 1.53 - 0.009 ML, r2 = 0.43). Our study shows that length dependence of Ca2+ sensitivity in intact skeletal muscle is diminished by caffeine. Caffeine also suppressed the length dependence of staircase potentiation, suggesting that the mechanism of this length dependence may be closely related to the mechanism for length dependence of Ca2+ sensitivity.

  16. Essential oil from Xylopia frutescens Aubl. reduces cytosolic calcium levels on guinea pig ileum: mechanism underlying its spasmolytic potential.

    PubMed

    Souza, Iara Leão Luna de; Correia, Ana Carolina de Carvalho; Araujo, Layanne Cabral da Cunha; Vasconcelos, Luiz Henrique César; Silva, Maria da Conceição Correia; Costa, Vicente Carlos de Oliveira; Tavares, Josean Fechine; Paredes-Gamero, Edgar Julian; Cavalcante, Fabiana de Andrade; Silva, Bagnólia Araújo da

    2015-09-16

    Xylopia frutescens Aubl. (embira, semente-de-embira or embira-vermelha), is used in folk medicine as antidiarrheal. The essential oil from its leaves (XF-EO) has been found to cause smooth muscle relaxation. Thus, the aim of this study was to investigate the spasmolytic action by which XF-EO acts on guinea pig ileum. The components of the XF-EO were identified by gas chromatography-mass spectrometry. Segments of guinea pig ileum were suspended in organ bath containing modified Krebs solution at 37 °C, bubbled with carbogen mixture under a resting tension of 1 g. Isotonic contractions were registered using kymographs and isometric contractions using force transducer coupled to an amplifier and computer. Fluorescence measurements were obtained with a microplate reader using Fluo-4. Forty-three constituents were identified in XF-EO, mostly mono- and sesquiterpenes. XF-EO has been found to cause relaxation on guinea pig ileum. The essential oil inhibited in a concentration-dependent manner both CCh- and histamine-induced phasic contractions, being more potent on histamine-induced contractions as well as antagonized histamine-induced cumulative contractions in a non-competitive antagonism profile. XF-EO relaxed in a concentration-dependent manner the ileum pre-contracted with KCl and histamine. Since the potency was smaller in organ pre-contracted with KCl, it was hypothesized that XF-OE would be acting as a K(+) channel positive modulator. In the presence of CsCl (non-selective K(+) channel blocker), the relaxant potency of XF-OE was not altered, indicating a non-participation of these channels. Moreover, XF-EO inhibited CaCl2-induced cumulative contractions in a depolarizing medium nominally without Ca(2+) and relaxed the ileum pre-contracted with S-(-)-Bay K8644 in a concentration-dependent manner, thus, was confirmed the inhibition of Ca(2+) influx through Cav1 by XF-EO. In cellular experiments, the viability of longitudinal layer myocytes from guinea pig ileum was not altered in the presence of XF-OE and the Fluo-4-associated fluorescence intensity in these intestinal myocytes stimulated by histamine was reduced by the essential oil, indicating a [Ca(2+)]c reduction. Spasmolytic action mechanism of XF-EO on guinea pig ileum can involve histaminergic receptor antagonism and Ca(2+) influx blockade, which results in [Ca(2+)]c reduction leading to smooth muscle relaxation.

  17. Protracted Counterinsurgency Chinese COIN Strategy in Xinjiang

    DTIC Science & Technology

    2008-05-22

    does not display a currently valid OMB control number . PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 22-05-2008...2. REPORT TYPE Monograph 3. DATES COVERED (From - To) July 2007 – May 2008 5a. CONTRACT NUMBER 5b. GRANT NUMBER 4. TITLE AND SUBTITLE...Protracted Counterinsurgency: Chinese COIN Strategy in Xinjiang 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 6. AUTHOR(S

  18. Preparation and Properties of High-T(sub c) Bi-Pb-Sr-Ca-Cu-O Thick Film Superconductors on YSZ Substrates

    NASA Technical Reports Server (NTRS)

    Hooker, Matthew W.

    1996-01-01

    An evaluation of four firing profiles was performed to determine the optimum processing conditions for producing high-T(sub c) Bi-Pb-Sr-Ca-Cu-O thick films on yttria-stabilized zirconia substrates. Using these four profiles, the effects of sintering temperatures of 830-850 C and soak times of 0.5 to 12 hours were examined. In this study, T-c, zero values of 100 K were obtained using a firing profile in which the films were sintered for 1.5 to 2 hours at 840 to 845 C and then quenched to room temperature. X-ray diffraction analyses of these specimens confirmed the presence of the high-T(sub c) phase. Films which were similarly fired and furnace cooled from the peak processing temperature exhibited a two-step superconductive transition to zero resistance, with T-c,zero values ranging from 85 to 92 K. The other firing profiles evaluated in this investigation yielded specimens which either exhibited critical transition temperatures below 90 K or did not exhibit a superconductive transition above 77 K.

  19. Improving tenderness of normal and callipyge lambs with calcium chloride.

    PubMed

    Clare, T L; Jackson, S P; Miller, M F; Elliott, C T; Ramsey, C B

    1997-02-01

    Effects of CaCl2 injection on meat quality traits of 10 normal and 10 callipyge phenotype crossbred lambs were studied. Primal cuts from one side of each carcass served as the control and cuts from the other side were injected. After storage for 14 d at 2 degrees C, chops were evaluated by Warner-Bratzler shear (WBS) force, trained sensory panel, and consumer sensory panel. Treatment of the muscles with 200 mM CaCl2 increased (P < .05) tenderness and lamb flavor intensity scores by the trained sensory panel and decreased (P < .05) WBS force in both normal and callipyge phenotypes. When callipyge muscles were not injected, consumers rated 94% of leg chops, 60% of loin chops, and 89.4% of shoulder chops acceptable in tenderness. However, when callipyge muscles were CaCl2-injected, consumers rated 96.5% of leg chops, 85.4% of loin chips, and 93.5% of shoulder chops acceptable in tenderness. Normal phenotype carcasses had more marbling (P < .05) in a firmer, finer-textured, brighter cherry red longissimus muscle. Injection of CaCl2 did not affect visual lean color or L, a or b values during retail display of the chops. However, CaCl2 injection decreased color uniformity, increased discoloration, and increased browning at d 2. Therefore, a 5% (wt/wt) injection of 200 mM CaCl2 solution can be applied to improve normal and callipyge lamb tenderness and reduce tenderness and juiciness variation without detrimental effects on other palatability traits when evaluated by trained sensory panelists or consumers.

  20. Endogenous and maximal sarcoplasmic reticulum calcium content and calsequestrin expression in type I and type II human skeletal muscle fibres.

    PubMed

    Lamboley, C R; Murphy, R M; McKenna, M J; Lamb, G D

    2013-12-01

    The relationship between sarcoplasmic reticulum (SR) Ca(2+) content and calsequestrin (CSQ) isoforms was investigated in human skeletal muscle. A fibre-lysing assay was used to quantify the endogenous Ca(2+) content and maximal Ca(2+) capacity of the SR in skinned segments of type I and type II fibres from vastus lateralis muscles of young healthy adults. Western blotting of individual fibres showed the great majority contained either all fast or all slow isoforms of myosin heavy chain (MHC), troponins C and I, tropomyosin and SERCA, and that the strontium sensitivity of the force response was closely indicative of the troponin C isoform present. The endogenous SR Ca(2+) content was slightly lower in type I compared to type II fibres (0.76 ± 0.03 and 0.85 ± 0.02 mmol Ca(2+) per litre of fibre, respectively), with virtually all of this Ca(2+) evidently being in the SR, as it could be rapidly released with a caffeine-low [Mg(2+)] solution (only 0.08 ± 0.01 and <0.07 mmol l(-1), respectively, remaining). The maximal Ca(2+) content that could be reached with SR Ca(2+) loading was 1.45 ± 0.04 and 1.79 ± 0.03 mmol l(-1) in type I and type II fibres, respectively (P < 0.05). In non-lysed skinned fibres, where the SR remained functional, repeated cycles of caffeine-induced Ca(2+) release and subsequent Ca(2+) reloading similarly indicated that (i) maximal SR Ca(2+) content was lower in type I fibres than in type II fibres (P < 0.05), and (ii) the endogenous Ca(2+) content represented a greater percentage of maximal content in type I fibres compared to type II fibres (∼59% and 41%, respectively, P < 0.05). Type II fibres were found on average to contain ∼3-fold more CSQ1 and ∼5-fold less CSQ2 than type I fibres (P < 0.001). The findings are consistent with the SR Ca(2+) content characteristics in human type II fibres being primarily determined by the CSQ1 abundance, and in type I fibres by the combined amounts of both CSQ1 and CSQ2.

  1. Endogenous and maximal sarcoplasmic reticulum calcium content and calsequestrin expression in type I and type II human skeletal muscle fibres

    PubMed Central

    Lamboley, C R; Murphy, R M; McKenna, M J; Lamb, G D

    2013-01-01

    The relationship between sarcoplasmic reticulum (SR) Ca2+ content and calsequestrin (CSQ) isoforms was investigated in human skeletal muscle. A fibre-lysing assay was used to quantify the endogenous Ca2+ content and maximal Ca2+ capacity of the SR in skinned segments of type I and type II fibres from vastus lateralis muscles of young healthy adults. Western blotting of individual fibres showed the great majority contained either all fast or all slow isoforms of myosin heavy chain (MHC), troponins C and I, tropomyosin and SERCA, and that the strontium sensitivity of the force response was closely indicative of the troponin C isoform present. The endogenous SR Ca2+ content was slightly lower in type I compared to type II fibres (0.76 ± 0.03 and 0.85 ± 0.02 mmol Ca2+ per litre of fibre, respectively), with virtually all of this Ca2+ evidently being in the SR, as it could be rapidly released with a caffeine-low [Mg2+] solution (only 0.08 ± 0.01 and <0.07 mmol l−1, respectively, remaining). The maximal Ca2+ content that could be reached with SR Ca2+ loading was 1.45 ± 0.04 and 1.79 ± 0.03 mmol l−1 in type I and type II fibres, respectively (P < 0.05). In non-lysed skinned fibres, where the SR remained functional, repeated cycles of caffeine-induced Ca2+ release and subsequent Ca2+ reloading similarly indicated that (i) maximal SR Ca2+ content was lower in type I fibres than in type II fibres (P < 0.05), and (ii) the endogenous Ca2+ content represented a greater percentage of maximal content in type I fibres compared to type II fibres (∼59% and 41%, respectively, P < 0.05). Type II fibres were found on average to contain ∼3–fold more CSQ1 and ∼5–fold less CSQ2 than type I fibres (P < 0.001). The findings are consistent with the SR Ca2+ content characteristics in human type II fibres being primarily determined by the CSQ1 abundance, and in type I fibres by the combined amounts of both CSQ1 and CSQ2. PMID:24127619

  2. Dollar Summary of Prime Contract Awards by Contractor, State or Country, and Place, FY 85. Part 1 (IDSCR Inc - Czetli Jess & Son In).

    DTIC Science & Technology

    1985-01-01

    m.-I-I.m.m0IIF- - . I00 I- I.-fI.-I- . 0 4 4 64*.4 444@da *444 004 4 o aG aea a& 4 *a 0 *a *a 6.-a *a60 4 e 4 GOO6Uea44 * Ao i 4 1 1 0 M a*a- -- 4-1...4 a~a .4 . 1 4 1 I -4 0 Z(0 = 0 0 CX o m ag m- C- m .-4.. 0c -* . a4 E 041 0 U C)1-0 1 W.C.Z0404 C 1C4 41 -C -C z. 40.- w - - Cx L C 0 40 -C -C 3-4...w . - " 0 0 14 ZI 0 6 " -I U0 > - z C aG 0I - 0 C w (0 61 ~- wo w g x b. I. . . .- . L 0 V 61 U 0 0 w w " CA I 0 U 61 4 4 U 61 1 E4 -C 4 -- I I 0 61

  3. Job Language Performance Requirements for MOS 11H. Heavy Antiarmor Weapons Crewman. Reference Soldier’s Manual Dated 16 November 1979.

    DTIC Science & Technology

    1979-11-16

    written content. The following are specific conditions found in this language task: Lists Information Descriptions Radiation readings off dosimeter ...m.nm.-vm4 ) mmM f n n m I--i -. -r MtO@g 4 4r 10 a P .4 ca oSl usm a 20 05-3 aui 0L -Z 2jS amw p VIL 11U0 u %310 0 c.a.c LoU & I.-1 M35 Z u -6 0 EIXU

  4. Calcium balance in mature male rats with unloaded hindlimbs

    NASA Technical Reports Server (NTRS)

    Navidi, Meena; Evans, Juliann; Wolinsky, Ira; Arnaud, Sara B.

    2004-01-01

    BACKGROUND: Calcium balances, regulated by the calcium endocrine system, are negative during spaceflight but have not been reported in flight simulation models using fully mature small animals. METHODS: We conducted two calcium (Ca) balance studies in 6-mo-old male rats exposed to a model that unloads the hindlimbs (HU) for 4 wk. Control (C) and HU rats were fed diets with 0.5% Ca in the first and 0.1% Ca in the second study. Housing in metabolic cages enabled daily food and water intake measurements as well as collections of urine and fecal specimens. At necropsy, blood was obtained for measures of Ca-regulating hormones. RESULTS: Both C and HU rats adjusted to housing and diets with decreases in body weight and negative Ca balances during the first week of each experiment. Thereafter, averages of Ca balances were more negative in the unloaded rats than controls: -8.1 vs. -1.6 mg x d(-1) in rats fed 0.5% (p < 0.05). This difference was not due to urinary Ca excretion since it was lower in HU than C rats (1.27 +/- 0.51 mg x d(-1) vs. 2.35 +/- 0.82 mg x d(-1), p < 0.05). Fecal Ca in HU rats exceeded dietary Ca by 4-7%, Restricting dietary Ca to 0.1% was followed by an increase in serum 1,25-dihydroxyvitamin D (1,25-D) and greater intestinal Ca absorption than in rats fed 0.5% Ca. Ca balances in rats fed 0.1% Ca were also more negative in HU than C rats (-2.4 vs. -0.03 mg x d(-1), p < 0.05). Parathyroid hormone (PTH) was suppressed and 1,25-D increased in HU rats fed 0.5% Ca. C rats fed 0.1% Ca had increased PTH and 1,25-D was the same as in the HU group. CONCLUSION: After adaptation, Ca balances were more negative in mature male rats with unloaded hindlimbs than controls, an effect from increased secretion and loss of endogenous fecal Ca associated with increased 1,25-D in Ca-replete and Ca-restricted rats.

  5. Effect of salbutamol on neuromuscular function in endurance athletes.

    PubMed

    Decorte, Nicolas; Bachasson, Damien; Guinot, Michel; Flore, Patrice; Levy, Patrick; Verges, Samuel; Wuyam, Bernard

    2013-10-01

    The potential ergogenic effects of therapeutic inhaled salbutamol doses in endurance athletes have been controversially discussed for decades. We hypothesized that salbutamol inhalation may increase peripheral muscle contractility, reduce fatigability, and improve force recovery after a localized exercise in endurance athletes. Eleven healthy, nonasthmatic male athletes with high aerobic capacities were recruited to be compared in a double-blinded, randomized crossover study of two dose levels of salbutamol (200 and 800 μg) and a placebo administered by inhalation before a quadriceps fatigue test. Subjects performed an incremental exercise protocol consisting in sets of 10 intermittent isometric contractions starting at 20% of maximum voluntary contraction (MVC) with 10% MVC increment until exhaustion. Femoral nerve magnetic stimulation was used during and after MVC to evaluate neuromuscular fatigue after each set, at task failure, and after 10 and 30 min of recovery. Initial MVC and evoked muscular responses were not modified with salbutamol (P > 0.05). The total number of submaximal contractions until task failure significantly differed between treatments (placebo, 72 ± 7; 200 µg, 78 ± 8; and 800 µg, 82 ± 7; P < 0.01). MVC and evoked muscular responses were similarly reduced with all treatments during the fatiguing task (all P > 0.05). Voluntary activation was unaffected by the fatiguing task and treatments (P > 0.05). Supratherapeutic inhaled doses of β2-agonists increased quadriceps endurance during an incremental and localized fatiguing task in healthy endurance-trained athletes without significant effect on neuromuscular fatigue. Further studies are needed to clarify the underlying mechanisms.

  6. 1-[1-(4-Chloro­phen­yl)ethyl­idene]carbono­hydrazide

    PubMed Central

    Du, Lingyun; Du, Lei; Wang, Shuhao

    2009-01-01

    The mol­ecular skeleton of the title mol­ecule, C9H11ClN4O, is essentially planar, the dihedral angle between the ring and the and N/N/C plane being 6.7 (3)°. In the crystal, inter­molecular N—H⋯O and N—H⋯N hydrogen bonds link the mol­ecules into ribbons propagated along [010]. PMID:21577542

  7. N-acetylcysteine-induced vasodilation involves voltage-gated potassium channels in rat aorta.

    PubMed

    Han, Wei-Qing; Zhu, Ding-Liang; Wu, Ling-Yun; Chen, Qi-Zhi; Guo, Shu-Jie; Gao, Ping-Jin

    2009-05-22

    N-acetylcysteine (NAC) has a protective effect against vascular dysfunction by decreasing the level of reactive oxygen species (ROS) in experimental and human hypertension. This study was designed to examine whether NAC would relax vascular rings in vitro via nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, extracellular Ca2+ and/or K+ channels. Rat aortic arteries were mounted in an organ bath, contracted with 0.1, 0.5 or 1 micromol/L phenylephrine to plateau, and the vasodilatory effect of NAC was examined in the absence or presence of ROS scavengers, inhibitors of NO-cGMP pathway or K+ channels. Vascular smooth muscle cells (VSMCs) were loaded with a calcium sensitive fluorescent dye fluo-3 AM, and [Ca2+](i) was determined with laser-scanning confocal microscopy. NAC (0.1-4 mmol/L) dose-dependently relaxed rat aorta pre-contracted with phenylephrine. Endothelium removal, endothelial nitric oxide synthase inhibitor N(omega)-Nitro-l-arginine (L-NNA) (100 micromol/L) or soluble guanylyl cyclase (sGC) inhibitor (ODQ) (10 micromol/L) did not affect NAC-induced vasodilation. In contrast, NAC-induced vasodilation was blunted after extracellular calcium was removed and calcium imaging showed that 4 mmol/L NAC quickly decreased [Ca2+](i) in fluo-3 AM loaded VSMCs. NAC-induced vasodilation was significantly reduced in the presence of voltage-gated K+ channels (Kv) inhibitor 4-aminopyridine (4-AP). The vasodilatory effect of NAC may be explained at least partly by activation of voltage-gated K+ channels.

  8. Age Differences in Dynamic Fatigability and Variability of Arm and Leg Muscles: Associations with Physical Function

    PubMed Central

    Senefeld, Jonathon; Yoon, Tejin; Hunter, Sandra K.

    2016-01-01

    Introduction It is not known whether the age-related increase in fatigability of fast dynamic contractions in lower limb muscles also occurs in upper limb muscles. We compared age-related fatigability and variability of maximal-effort repeated dynamic contractions in the knee extensor and elbow flexor muscles; and determined associations between fatigability, variability of velocity between contractions and functional performance. Methods 35 young (16 males; 21.0±2.6 years) and 32 old (18 males; 71.3±6.2 years) adults performed a dynamic fatiguing task involving 90 maximal-effort, fast, concentric, isotonic contractions (1 contraction/3 s) with a load equivalent to 20% maximal voluntary isometric contraction (MVIC) torque with the elbow flexor and knee extensor muscles on separate days. Old adults also performed tests of balance and walking endurance. Results Old adults had greater fatigue-related reductions in peak velocity compared with young adults for both the elbow flexor and knee extensor muscles (P<0.05) with no sex differences (P>0.05). Old adults had greater variability of peak velocity during the knee extensor, but not during the elbow flexor fatiguing task. The age difference in fatigability was greater for the knee extensor muscles (35.9%) compared with elbow flexor muscles (9.7%, P<0.05). Less fatigability of the knee extensor muscles was associated with greater walking endurance (r=−0.34, P=0.048) and balance (r=−0.41, P=0.014) among old adults. Conclusions An age-related increase in fatigability of a dynamic fatiguing task was greater for the knee extensor compared with the elbow flexor muscles in males and females, and greater fatigability was associated with lesser walking endurance and balance. PMID:27989926

  9. Comparison between maximal lengthening and shortening contractions for biceps brachii muscle oxygenation and hemodynamics.

    PubMed

    Muthalib, Makii; Lee, Hoseong; Millet, Guillaume Y; Ferrari, Marco; Nosaka, Kazunori

    2010-09-01

    Eccentric contractions (ECC) require lower systemic oxygen (O2) and induce greater symptoms of muscle damage than concentric contractions (CON); however, it is not known if local muscle oxygenation is lower in ECC than CON during and following exercise. This study compared between ECC and CON for changes in biceps brachii muscle oxygenation [tissue oxygenation index (TOI)] and hemodynamics [total hemoglobin volume (tHb)=oxygenated-Hb+deoxygenated-Hb], determined by near-infrared spectroscopy over 10 sets of 6 maximal contractions of the elbow flexors of 10 healthy subjects. This study also compared between ECC and CON for changes in TOI and tHb during a 10-s sustained and 30-repeated maximal isometric contraction (MVC) task measured immediately before and after and 1-3 days following exercise. The torque integral during ECC was greater (P<0.05) than that during CON by approximately 30%, and the decrease in TOI was smaller (P<0.05) by approximately 50% during ECC than CON. Increases in tHb during the relaxation phases were smaller (P<0.05) by approximately 100% for ECC than CON; however, the decreases in tHb during the contraction phases were not significantly different between sessions. These results suggest that ECC utilizes a lower muscle O2 relative to O2 supply compared with CON. Following exercise, greater (P<0.05) decreases in MVC strength and increases in plasma creatine kinase activity and muscle soreness were evident 1-3 days after ECC than CON. Torque integral, TOI, and tHb during the sustained and repeated MVC tasks decreased (P<0.01) only after ECC, suggesting that muscle O2 demand relative to O2 supply during the isometric tasks was decreased after ECC. This could mainly be due to a lower maximal muscle mass activated as a consequence of muscle damage; however, an increase in O2 supply due to microcirculation dysfunction and/or inflammatory vasodilatory responses after ECC is recognized.

  10. TEMTADS Adjunct Sensor Systems Hand-held EMI Sensor for Cued UXO Discrimination (ESTCP MR-200807) and Man-Portable EMI Array for UXO Detection and Discrimination (ESTCP MR-200909) Cost and Performance Report

    DTIC Science & Technology

    2012-06-27

    notes and team orienteering functions. Data collection with the MP system at the former Camp Beale, CA is shown in Figure 5- 2 (right). 5.3.3...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/ 6110 --12-9424 TEMTADS Adjunct Sensor Systems Hand-held EMI Sensor for Cued UXO...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 2 . REPORT TYPE1. REPORT DATE (DD

  11. All Prime Contract Awards by State or Country, Place, and Contractor, FY 85. Part 6 (Alachua, Florida - Winder, Georgia).

    DTIC Science & Technology

    1985-01-01

    4aC I 00 < M Uz 00(000000cc0000000001. U 0LALLAAOO 104I < 40(0OO0O4NN0.I-C10 ml W N00NNNN-4-I - M I .00 . . ~ .’l ~ C 0 0 .0- . .. . WWW W0r.000O LA...40 -4 -4 -V4I, 0.2c W~n r-. CLn U). C CC rA. IA. I ca 0 sO N 4 r4-4 4 --*L -qU l4 .00)L . m -IU NY mQ 4 *ww4CI www "Mm<)C, C’ oC)Co ) -IC44 -40 .. 40)C...10 ) -4 0 N 0 * C 1) 0 0N0 0 N 0 0 00’ mo oo* 𔃺 (0’ 4-’ in L4)4)-)- -n =0 0 0M- =OO- = 0. 30w~ww -4c) -4w www -40) -4-4n~ - -4mmac L44 0-- 403 01 0

  12. Canada’s northern food subsidy Nutrition North Canada: a comprehensive program evaluation

    PubMed Central

    Galloway, Tracey

    2017-01-01

    ABSTRACT Background: Nutrition North Canada (NNC) is a retail subsidy program implemented in 2012 and designed to reduce the cost of nutritious food for residents living in Canada’s remote, northern communities. The present study evaluates the extent to which NNC provides access to perishable, nutritious food for residents of remote northern communities. Design: Program documents, including fiscal and food cost reports for the period 2011–2015, retailer compliance reports, audits of the program, and the program’s performance measurement strategy are examined for evidence that the subsidy is meeting its objectives in a manner both comprehensive and equitable across regions and communities. Results: NNC lacks price caps or other means of ensuring food is affordable and equitably priced in communities. Gaps in food cost reporting constrain the program’s accountability. From 2011–15, no adjustments were made to community eligibility, subsidy rates, or the list of eligible foods in response to information provided by community members, critics, the Auditor General of Canada, and the program’s own Advisory Board. Measures to increase program accountability, such as increasing subsidy information on point-of-sale receipts, make NNC more visible but do nothing to address underlying accountability issues Conclusions: The current structure and regulatory framework of NNC are insufficient to ensure the program meets its goal. Both the volume and cost of nutritious food delivered to communities is highly variable and dependent on factors such as retailers’ pricing practices, over which the program has no control. It may be necessary to consider alternative forms of policy in order to produce sustainable improvements to food security in remote, northern communities. PMID:28151097

  13. Evaluation of RET Tyrosine Kinase as a Novel Driver of Prostatic Small Cell Neuroendocrine Carcinoma

    DTIC Science & Technology

    2015-08-01

    PRINCIPAL INVESTIGATOR: Justin M. Drake, Ph.D. CONTRACTING ORGANIZATION : University of California, Los Angeles Los Angeles, CA 90095 REPORT DATE...PROJECT NUMBER 5e. TASK NUMBER E-Mail: jdrake@mednet.ucla.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8...PERFORMING ORGANIZATION REPORT NUMBER University of California, Los Angeles 11000 Kinross Ave Ste 102 Los Angeles, CA 90095-2000 9. SPONSORING

  14. Materials fatigue initiates eccentric contraction-induced injury in rat soleus muscle.

    PubMed Central

    Warren, G L; Hayes, D A; Lowe, D A; Prior, B M; Armstrong, R B

    1993-01-01

    1. The initiation of exercise-induced muscle injury is thought to be the result of high tensile stresses produced in the muscle during eccentric contractions. Materials science theory suggests that high tensile stresses could initiate the injury during the first eccentric contraction (normal stress theory) or after multiple eccentric contractions (materials fatigue). It was the objective of this study to investigate the two possibilities. 2. Rat soleus muscles (n = 66; 11 protocols with 6 muscles per protocol) were isolated, placed in an oxygenated Krebs-Ringer buffer at 37 degrees C, and baseline measurements were made. The muscle then performed an injury protocol which consisted of between zero and ten eccentric contractions (muscle starting length = 0.90 soleus muscle length, L0; length change = 0.25 L0; velocity = 1.5 L0/s; peak force = 180% maximal isometric tetanic tension (P0); time between contractions = 4 min; total duration of the injury protocol = 40 min). At the end of the injury protocol, the muscle was incubated in buffer for 1 h; every 15 min, an isometric twitch and tetanus were performed and lactate dehydrogenase (LDH) release was measured. Total muscle [Ca2+] was measured at the end of the incubation. 3. Change-point regression analysis indicates that at 0 min into the incubation, declines in P0, maximal rate of tension development (+dP/dt), maximal rate of relaxation (-dP/dt), and muscle stiffness (dP/dx) became significantly greater after eight eccentric contractions (p < or = 0.05). No relation was found between the number of eccentric contractions performed and the LDH activity at 0 min into the incubation, although after 60 min of incubation, LDH activity in the buffer was linearly related to eccentric contraction number (p = 0.01). There was no relationship between total muscle [Ca2+] and eccentric contraction number. These findings support the materials fatigue hypothesis of exercise-induced muscle injury. PMID:8229814

  15. [The use of pectin-containing enterosorbents in exposure to radionuclides and heavy metals].

    PubMed

    Trakhtenberg, I M; Litenko, V A; Dereviago, I B; Demchenko, P I; Mikhaĭlovskiĭ, S V

    1992-05-01

    The pectin-vitamin composition (PVC) and its complex with active carbon (AC) was investigated for use as an oral sorbent to protect radionuclide (Sr-85, Cs-137) accumulation. PVC is composed of the natural mixture of cellulose, pectin (Ca-salt), flavonoides, vitamins of the B-group, PP and C. Investigation of PVC radioprotective action was carried out on the two groups of rats (n = 30) which received 1306 Bk/animal of Sr-85 or 343 Bk/animal of Cs-137 daily. One of the group of rats received every day also 300 mg of PVC. After 30 days level of Sr-85 was less by 56.6%, level of Cs = 137 was less by 27.6% in PVC-treated than in the control group (P < 0.05). Composite sorbent consisting of PVC and AC was slightly less effective in removing of Sr and Cs.

  16. Activation Dependence of Stretch Activation in Mouse Skinned Myocardium: Implications for Ventricular Function

    PubMed Central

    Stelzer, Julian E.; Larsson, Lars; Fitzsimons, Daniel P.; Moss, Richard L.

    2006-01-01

    Recent evidence suggests that ventricular ejection is partly powered by a delayed development of force, i.e., stretch activation, in regions of the ventricular wall due to stretch resulting from torsional twist of the ventricle around the apex-to-base axis. Given the potential importance of stretch activation in cardiac function, we characterized the stretch activation response and its Ca2+ dependence in murine skinned myocardium at 22°C in solutions of varying Ca2+ concentrations. Stretch activation was induced by suddenly imposing a stretch of 0.5–2.5% of initial length to the isometrically contracting muscle and then holding the muscle at the new length. The force response to stretch was multiphasic: force initially increased in proportion to the amount of stretch, reached a peak, and then declined to a minimum before redeveloping to a new steady level. This last phase of the response is the delayed force characteristic of myocardial stretch activation and is presumably due to increased attachment of cross-bridges as a consequence of stretch. The amplitude and rate of stretch activation varied with Ca2+ concentration and more specifically with the level of isometric force prior to the stretch. Since myocardial force is regulated both by Ca2+ binding to troponin-C and cross-bridge binding to thin filaments, we explored the role of cross-bridge binding in the stretch activation response using NEM-S1, a strong-binding, non-force–generating derivative of myosin subfragment 1. NEM-S1 treatment at submaximal Ca2+-activated isometric forces significantly accelerated the rate of the stretch activation response and reduced its amplitude. These data show that the rate and amplitude of myocardial stretch activation vary with the level of activation and that stretch activation involves cooperative binding of cross-bridges to the thin filament. Such a mechanism would contribute to increased systolic ejection in response to increased delivery of activator Ca2+ during excitation–contraction coupling. PMID:16446502

  17. Evaluating the Ergonomics of Flexible Ureteroscopy.

    PubMed

    Ludwig, Wesley W; Lee, Gyusung; Ziemba, Justin B; Ko, Joan S; Matlaga, Brian R

    2017-10-01

    To date, the ergonomics of flexible ureteroscopy (URS) have not been well described. We performed a study to assess the biomechanical stresses on urologists performing URS and to investigate the effect of ureteroscope type on these parameters. Electromyography (EMG) was used to quantify the activation level of muscle groups involved in URS. Surface EMG electrodes (Delsys, Boston, MA) were placed on the right and left thenar, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), biceps, triceps, and deltoid. Three endoscopes were studied: single-use digital (Boston Scientific LithoVue), reusable digital (Karl Storz Flex-X c ), and reusable fiber-optic (Karl Storz Flex-X 2 ). Each ureteroscope was used to perform a set sequence of navigation and procedural tasks in a training model. EMG data were processed and normalized to compare the maximum voluntary contractions between muscle groups. Cumulative muscular workload (CMW) and average muscular work per second (AWS) were used for comparative analysis. For navigational tasks, CMW and AWS were greatest for the ECU, followed in descending order by right and left thenar, FCU, biceps, deltoid, and triceps. For procedural tasks, CMW and AWS were greatest for the right thenar, followed in descending order by the left thenar, ECU, FCU, triceps, biceps, and deltoid. During navigational tasks, both LithoVue and Flex-X c had lower CMWs for every muscle group than Flex-X 2 (p < 0.05). LithoVue and Flex-X c had similar AWS and both were lower than Flex-X 2 for the right thenar, ECU, biceps, and deltoid activation (p < 0.05). During procedural tasks, both LithoVue and Flex-X c had lower CMWs and AWS for right and left thenar, ECU, and biceps than Flex-X 2 (p < 0.05). This study provides the first description of EMG-measured ergonomics of URS. Both the single-use and reusable digital ureteroscopes have similar profiles, and both have significantly better ergonomic metrics than the reusable fiber-optic ureteroscope.

  18. Reliability of near-infrared spectroscopy for measuring biceps brachii oxygenation during sustained and repeated isometric contractions.

    PubMed

    Muthalib, Makii; Millet, Guillaume Y; Quaresima, Valentina; Nosaka, Kazunori

    2010-01-01

    We examine the test-retest reliability of biceps brachii tissue oxygenation index (TOI) parameters measured by near-infrared spectroscopy during a 10-s sustained and a 30-repeated (1-s contraction, 1-s relaxation) isometric contraction task at 30% of maximal voluntary contraction (30% MVC) and maximal (100% MVC) intensities. Eight healthy men (23 to 33 yr) were tested on three sessions separated by 3 h and 24 h, and the within-subject reliability of torque and each TOI parameter were determined by Bland-Altman+/-2 SD limits of agreement plots and coefficient of variation (CV). No significant (P>0.05) differences between the three sessions were found for mean values of torque and TOI parameters during the sustained and repeated tasks at both contraction intensities. All TOI parameters were within+/-2 SD limits of agreement. The CVs for torque integral were similar between the sustained and repeated task at both intensities (4 to 7%); however, the CVs for TOI parameters during the sustained and repeated task were lower for 100% MVC (7 to 11%) than for 30% MVC (22 to 36%). It is concluded that the reliability of the biceps brachii NIRS parameters during both sustained and repeated isometric contraction tasks is acceptable.

  19. Dependable Real-Time Systems

    DTIC Science & Technology

    1991-09-30

    0196 or 413 545-0720 PI E-mail Address: krithi@nirvan.cs.umass.edu, stankovic(ocs.umass.edu Grant or Contract Title: Dependable Real - Time Systems Grant...Dependable Real - Time Systems " Grant or Contract Number: N00014-85-k-0398 L " Reporting Period: 1 Oct 87 - 30 Sep 91 , 2. Summary of Accomplishments ’ 2.1 Our...in developing a sound approach to scheduling tasks in complex real - time systems , (2) developed a real-time operating system kernel, a preliminary

  20. A new series of highly potent growth hormone-releasing peptides derived from ipamorelin.

    PubMed

    Ankersen, M; Johansen, N L; Madsen, K; Hansen, B S; Raun, K; Nielsen, K K; Thogersen, H; Hansen, T K; Peschke, B; Lau, J; Lundt, B F; Andersen, P H

    1998-09-10

    A new series of GH secretagogues derived from ipamorelin is described. In an attempt to obtain oral bioavailability, by reducing the size and the number of potential hydrogen-bonding sites of the compounds, a strategy using the peptidomimetic fragment 3-(aminomethyl)benzoic acid and sequential backbone N-methylations was applied. Several compounds from this series release GH with high in vitro potency and efficacy in a rat pituitary cell assay and high in vivo potency and efficacy in anesthetized rats. The tetrapeptide NNC 26-0235 (3-(aminomethyl)benzoyl-D-2Nal-N-Me-D-Phe-Lys-NH2) shows, following iv administration, comparable in vivo potency to ipamorelin, GHRP-2, and GHRP-6 with an ED50 in swine at 2 nmol/kg. NNC 26-0235 demonstrated a 10% oral bioavailability in dogs, and NNC 26-0235 and ipamorelin were able to increase basal GH level by more than 10-fold after oral administration of a dose of 1.8 and 2.7 mg/kg, respectively. The tripeptide NNC 26-0323 (3-(aminomethyl)benzoic acid-N-Me-D-2Nal-N-Me-D-Phe-ol) which showed moderate in vitro potency but lacked in vivo potency demonstrated a 20% oral bioavailability in rats.

  1. Mechanisms of multiple neurotransmitters in the effects of Lycopene on brain injury induced by Hyperlipidemia.

    PubMed

    Yang, Weichun; Shen, Ziyi; Wen, Sixian; Wang, Wei; Hu, Minyu

    2018-02-07

    Lycopene is a kind of carotenoid, with a strong capacity of antioxidation and regulating the bloodlipid. There has been some evidence that lycopene has protective effects on the central nervous system, but few studies have rigorously explored the role of neurotransmitters in it. Therefore, the present study was designed to investigate the effects of several neurotransmitters as lycopene exerts anti-injury effects induced by hyperlipidemia. Eighty adult SD rats, half male and half female, were randomly divided into eight groups on the basis of serum total cholesterol (TC) levels and body weight. There was a control group containing rats fed a standard laboratory rodent chow diet (CD); a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil - this is also called a CCT diet) group; a positive group (CCT + F) fed CCT, supplemented with 10 mg·kg·bw - 1 ·d - 1 fluvastatin sodium by gastric perfusion; and lycopene groups at five dose levels (CCT + LYCO) fed with CCT and supplied lycopene at doses of 5, 25, 45, 65, and 85 mg·kg·bw - 1 ·d - 1 . The levels of TC, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), oxidized low density lipoprotein (ox-LDL), low-density lipoprotein receptor (LDLR), nerve growth factor (NGF), glutamic acid (Glu), Gamma aminobutyric acid (GABA), dopamine (DA), 5-hydroxytryptamine (5-HT), N-methyl-D-aspartate (NMDA1R), GABA A , 5-HT 1 , D 1 , and apoptosis-related proteins Caspase3, bax, and bcl-2 were measured after the experiment. Nissl staining was adopted to observe the morphological changes in neurons. At the end of the experiment, the levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain as well as the content of Glu, DA, NMDA, and D 1 in the brain of rats in the CCT group were higher than those in the control group (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABA A , 5-HT 1 , and neuron quantities in the hippocampal CA1 and CA3 areas were lower than those in the control group (P<0.05). Compared to the CCT group, levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain, as well as the content of Glu, DA and the expression of pro-apoptotic Caspase3 in the brain decreased in the rats with lycopene (25 mg to 85 mg) added to the diet (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABA A , and 5-HT 1 as well as the expression of anti-apoptotic bcl-2 and the neuron quantity in hippocampal CA1 and CA3 areas increased (P<0.05); further, the hippocampal cells were closely arranged. Lycopene dose was negatively correlated with the levels of TC, TG, and LDL-C in the serum and brain as well as levels of IL-1, TNF-α, ox-LDL, Glu/GABA, NMDA1R, and Caspase3 (P<0.05); it was positively correlated with the levels of LDLR, NGF, 5-HT, 5-HT 1 , GABA A , bcl-2, and the neuron quantity in hippocampal CA1 and CA3 areas (P<0.05). Lycopene exerts anti-injury effects in the brain as-induced by hyperlipidemia. It can inhibit the elevation of serum TC, TG, and LDL-C in rats with hyperlipidemia while indirectly affecting the levels of TC, TG, and LDL-C in the brain, leading to a reduction in ox-LDL, IL-1, and TNF-α in the brain. This inhibits the release of Glu, which weakens nerve toxicity and downregulates pro-apoptotic Caspase3. Lycopene also plays an anti-injury role by promoting the release of the inhibitory neurotransmitter GABA and 5-HT, which enhances the protective effect, and by upregulating the anti-apoptotic bcl-2.

  2. The contribution of inositol 1,4,5-trisphosphate and ryanodine receptors to agonist-induced Ca(2+) signaling of airway smooth muscle cells.

    PubMed

    Bai, Yan; Edelmann, Martin; Sanderson, Michael J

    2009-08-01

    The relative contribution of inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)Rs) and ryanodine receptors (RyRs) to agonist-induced Ca(2+) signaling in mouse airway smooth muscle cells (SMCs) was investigated in lung slices with phase-contrast or laser scanning microscopy. At room temperature (RT), methacholine (MCh) or 5-hydroxytryptamine (5-HT) induced Ca(2+) oscillations and an associated contraction in small airway SMCs. The subsequent exposure to an IP(3)R antagonist, 2-aminoethoxydiphenyl borate (2-APB), inhibited the Ca(2+) oscillations and induced airway relaxation in a concentration-dependent manner. 2-APB also inhibited Ca(2+) waves generated by the photolytic release of IP(3). However, the RyR antagonist ryanodine had no significant effect, at any concentration, on airway contraction or agonist- or IP(3)-induced Ca(2+) oscillations or Ca(2+) wave propagation. By contrast, a second RyR antagonist, tetracaine, relaxed agonist-contracted airways and inhibited agonist-induced Ca(2+) oscillations in a concentration-dependent manner. However, tetracaine did not affect IP(3)-induced Ca(2+) release or wave propagation nor the Ca(2+) content of SMC Ca(2+) stores as evaluated by Ca(2+)-release induced by caffeine. Conversely, both ryanodine and tetracaine completely blocked agonist-independent slow Ca(2+) oscillations induced by KCl. The inhibitory effects of 2-APB and absence of an effect of ryanodine on MCh-induced airway contraction or Ca(2+) oscillations of SMCs were also observed at 37 degrees C. In Ca(2+)-permeable SMCs, tetracaine inhibited agonist-induced contraction without affecting intracellular Ca(2+) levels indicating that relaxation also resulted from a reduction in Ca(2+) sensitivity. These results indicate that agonist-induced Ca(2+) oscillations in mouse small airway SMCs are primary mediated via IP(3)Rs and that tetracaine induces relaxation by both decreasing Ca(2+) sensitivity and inhibiting agonist-induced Ca(2+) oscillations via an IP(3)-dependent mechanism.

  3. Deoxycholic acid inhibits smooth muscle contraction via protein kinase C-dependent modulation of L-type Ca2+ channels in rat proximal colon.

    PubMed

    Hu, Liu-Dan; Yu, Bao-Ping; Yang, Bin

    2012-10-01

    The aim of this study was to investigate the effects of deoxycholic acid (DCA) on the contractions of rat proximal colonic smooth muscle (PCSM) in vitro. The contractile response of rat PCSM strips was tested using a polyphysio-graph. The whole cell patch-clamp technique was also used in rat colonic smooth muscle cells (SMCs) isolated by an enzymatic procedure to record the L-type calcium current (I(Ca-L)) prior to and following the application of various concentrations of DCA. The application of DCA (10(-6)-10(-4) M) decreased the amplitude of spontaneous contractions of the PCSM strips in a dose-dependent manner. The administration of DCA (10(-5) M) caused the relaxation of isolated smooth muscle strips pre-contracted by acetylcholine (Ach) or KCl (by 12.2±1.5 and 16.3±6.9%, respectively). The concentration-response curve of CaCl2 was shifted to the right. Pre-treatment of the strips with the protein kinase C (PKC) inhibitor chelerythrine (1 µM) significantly attenuated the effects of DCA on the strips pre-contracted by Ach. DCA reduced the peak I(Ca-L) by 6.02±0.87% at 10(-6) M, 15.02±1.73% at 10(-5) M and 47.14±3.79% at 10(-4) M. DCA shifted the current-voltage (I-V) curve of ICa-L upward, but the contour of the I-V curve was unchanged, and the peak current-induced voltage remained at 0 mV. Pre-treatment with chelerythrine (1 µM) blocked the actions of DCA on the I(Ca-L). Taken together, the actions of DCA on I(Ca-L) in rat colonic SMCs contributed to a negative inotropic effect. These actions appear to be mediated through protein kinase C. Furthermore, this study suggests another possible mechanism for the DCA-related modulation of gastrointestinal motility.

  4. Cognitive Task Analysis of the HALIFAX-Class Operations Room Officer

    DTIC Science & Technology

    1999-03-10

    Image Cover Sheet CLASSIFICATION SYSTEM NUMBER 510918 UNCLASSIFIED llllllllllllllllllllllllllllllllllllllll TITLE COGNITIVE TASK ANALYSIS OF THE...DATES COVERED 00-00-1999 to 00-00-1999 4. TITLE AND SUBTITLE Cognitive Task Analysis of the HALIFAX-Class Operations Room Officer 5a. CONTRACT...Ontario . ~ -- . ’ c ... - Incorporated Cognitive Task Analysis of the HALIFAX-Class Operations Room Officer: PWGSC Contract No. W7711-7-7404/001/SV

  5. f-Elements in ionic liquids: A synthetic, spectroscopic and electrochemical study

    NASA Astrophysics Data System (ADS)

    Bhatt, Anand Indravadan

    This thesis reports on chemical research directed towards the utilisation of low temperature ionic liquids (LTILs) for the electrorefming of uranium and plutonium from spent nuclear fuel. Initial studies focus on evaluating the relevant physical and electrochemical properties of LTILs. One room temperature ionic liquid, [(CH[3])[3]N(n-C[4]H[9])][N(SO[2]CF[3])[2

  6. Effect of vitamin C concentration and co-injection with calcium chloride on beef retail display color.

    PubMed

    Wheeler, T L; Koohmaraie, M; Shackelford, S D

    1996-08-01

    The objectives of these experiments were to determine 1) the most effective vitamin C concentration to stabilize color of beef cuts during retail display and 2) the effect on color of incorporating vitamin C into a calcium chloride (CaCl2) injection solution. Top round cuts (semimembranosus and adductor) were injected with 5% by weight of a 0, .25, .5, 1, 2, or 4% sodium ascorbate solution (Exp. 1) or a 0, .5, 1, or 1.5% sodium ascorbate solution (Exp. 2). In Exp. 1, vitamin C resulted in more (P < .05) stable lean color during 9 degrees C display, and .5, 1, and 2% vitamin C were most (P < .05) effective. In Exp. 2, all concentrations of vitamin C maintained redder (P < .05) steaks after 3, 5, and 7 d of display than control steaks and had a lower (P < .05) percentage of surface discoloration after 5 and 7 d of display at 1 degree C. Experiment 3 used beef bottom round cuts (biceps femoris) to compare control, vitamin C- (1%), CaCl2-(200 mM) and vitamin C + CaCl2-treated steaks displayed at 1 degree C. Calcium chloride-treated steaks were more (P < .05) brown and had a higher (P < .05) percentage of surface discoloration on d 5 and 7 than control steaks, whereas steaks treated with vitamin C or vitamin C + CaCl2 were more (P < .05) red and had lower (P < .05) discoloration on d 5 and 7 than control steaks. Vitamin C can be injected into beef subprimals to enhance lean color stability and extend retail display life. Vitamin C also can be used in combination with CaCl2 to offset potential color deterioration, after 5 d of display, due to salt-induced oxidation.

  7. Cognitive Ameliorating Effect of Acanthopanax koreanum Against Scopolamine-Induced Memory Impairment in Mice.

    PubMed

    Lee, Sunhee; Park, Ho Jae; Jeon, Se Jin; Kim, Eunji; Lee, Hyung Eun; Kim, Haneul; Kwon, Yubeen; Zhang, Jiabao; Jung, In Ho; Ryu, Jong Hoon

    2017-03-01

    Acanthopanax koreanum Nakai (Araliaceae) is one of the most widely cultivated medicinal plants in Jeju Island, Korea, and the roots and stem bark of A. koreanum have been traditionally used as a tonic agent for general weakness. However, the use of A. koreanum for general weakness observed in the elderly, including those with declined cognitive function, has not been intensively investigated. This study was performed to investigate the effect of the ethanol extract of A. koreanum (EEAK) on cholinergic blockade-induced memory impairment in mice. To evaluate the ameliorating effects of EEAK against scopolamine-induced memory impairment, mice were orally administered EEAK (25, 50, 100, or 200 mg/kg), and several behavioral tasks, including a passive avoidance task, the Y-maze, and a novel object recognition task, were employed. Besides, western blot analysis was conducted to examine whether EEAK affected memory-associated signaling molecules, such as protein kinase B (Akt), Ca 2+ /calmodulin-dependent protein kinase II (CaMKII), and cAMP response element-binding protein (CREB). The administration of EEAK (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in the passive avoidance task, the Y-maze, and the novel object recognition task. The phosphorylation levels of both Akt and CaMKII were significantly increased by approximately two-fold compared with the control group because of the administration of EEAK (100 or 200 mg/kg) (p < 0.05). Moreover, the phosphorylation level of CREB was also significantly increased compared with the control group by the administration of EEAK (200 mg/kg) (p < 0.05). The present study suggests that EEAK ameliorates the cognitive dysfunction induced by the cholinergic blockade, in part, via several memory-associated signaling molecules and may hold therapeutic potential against cognitive dysfunction, such as that presented in neurodegenerative diseases, for example, Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Action of a NO donor on the excitation–contraction pathway activated by noradrenaline in rat superior mesenteric artery

    PubMed Central

    Ghisdal, Philippe; Gomez, Jean-Pierre; Morel, Nicole

    2000-01-01

    The aim of the present study was to investigate the actions of NO donors in ratsuperior mesenteric artery stimulated with noradrenaline by studying their effects on isometric tension, membrane potential (Vm), cytosolic calcium concentration ([Ca2+]cyt) and accumulation of inositol phosphates. In unstimulated arteries, SNAP (S-nitroso-N-acetylpenicillamine, 10 μm) hyperpolarised Vm by 3.0 ± 0.5 mV (n = 9). In KCl-stimulated arteries, SNAP relaxed contraction without changing Vm and [Ca2+]cyt. In noradrenaline-stimulated arteries, SNAP relaxed tension, repolarised Vm and decreased [Ca2+]cyt with the same potency. Responses to SNAP were unaffected by the following K+ channel blockers: glibenclamide, 4-aminopyridine, apamin and charybdotoxin, and by increasing the KCl concentration to 25 mM. In SNAP-pretreated arteries, the production of inositol phosphates and the contraction stimulated by noradrenaline were inhibited similarly. The guanylate cyclase inhibitor ODQ abolished the increase in cyclic GMP content evoked by SNAP and inhibited the effects of SNAP on contraction, Vm and accumulation of inositol phosphates in noradrenaline-stimulated artery. These results indicate that, in rat superior mesenteric arteries activated by noradrenaline, inhibition of production of inositol phosphates is responsible for the effects of the NO donor SNAP on membrane potential, [Ca2+]cyt and contraction through a cyclic GMP-dependent mechanism. PMID:10618154

  9. Structural basis for the regulation of muscle contraction by troponin and tropomyosin.

    PubMed

    Galińska-Rakoczy, Agnieszka; Engel, Patti; Xu, Chen; Jung, Hyunsuk; Craig, Roger; Tobacman, Larry S; Lehman, William

    2008-06-20

    The molecular switching mechanism governing skeletal and cardiac muscle contraction couples the binding of Ca2+ on troponin to the movement of tropomyosin on actin filaments. Despite years of investigation, this mechanism remains unclear because it has not yet been possible to directly assess the structural influence of troponin on tropomyosin that causes actin filaments, and hence myosin-crossbridge cycling and contraction, to switch on and off. A C-terminal domain of troponin I is thought to be intimately involved in inducing tropomyosin movement to an inhibitory position that blocks myosin-crossbridge interaction. Release of this regulatory, latching domain from actin after Ca2+ binding to TnC (the Ca2+ sensor of troponin that relieves inhibition) presumably allows tropomyosin movement away from the inhibitory position on actin, thus initiating contraction. However, the structural interactions of the regulatory domain of TnI (the "inhibitory" subunit of troponin) with tropomyosin and actin that cause tropomyosin movement are unknown, and thus, the regulatory process is not well defined. Here, thin filaments were labeled with an engineered construct representing C-terminal TnI, and then, 3D electron microscopy was used to resolve where troponin is anchored on actin-tropomyosin. Electron microscopy reconstruction showed how TnI binding to both actin and tropomyosin at low Ca2+ competes with tropomyosin for a common site on actin and drives tropomyosin movement to a constrained, relaxing position to inhibit myosin-crossbridge association. Thus, the observations reported reveal the structural mechanism responsible for troponin-tropomyosin-mediated steric interference of actin-myosin interaction that regulates muscle contraction.

  10. Statistical optimization of an RP-HPLC method for the determination of selected flavonoids in berry juices and evaluation of their antioxidant activities.

    PubMed

    Ciric, Andrija; Jelikic-Stankov, Milena; Cvijovic, Milica; Djurdjevic, Predrag

    2018-04-01

    An isocratic RP-HPLC method for the separation and identification of selected flavonoids (quercetin, rutin, luteolin-7-O-glucoside, kaempferol and kaempferol-3-O-glucoside) in commercial berry juices (blackcurrant, blueberry, red raspberry and cherry) was developed with the aid of central composite design and response surface methodology. The optimal separation conditions were a mobile phase of 85:15 (% v/v) water-acetonitrile, pH 2.8 (adjusted with formic acid), flow rate 0.5 mL min -1 and column temperature 35°C. The obtained levels of bioflavonoids (mg per 100 mL of juice) were as follows: for quercetin, ca. 0.21-5.12; for kaempferol, ca. 0.05-1.2; for rutin, ca. 0.4-6.5; for luteolin-7-O-glucoside, ca. 5.6-10.2; and for kaempferol-3-O-glucoside, ca. 0.02-0.12. These are considerably lower than the values in fresh fruits. Total phenolic, flavonoid and anthocyanin contents were determined spectrophotometrically. Total flavonoid content varied as follows: blackcurrant > blueberry > red raspberry > cherry. The antioxidant activity of juice extracts (DPPH and ABTS methods) expressed as IC 50 values varied from 8.56 to 14.05 mg L -1 . These values are ~2.5-3 times lower than quercetin, ascorbic acid and Trolox®, but compared with rutin and butylhydroxytoluene, berries show similar or better antioxidant activity by both the DPPH and ABTS methods. Copyright © 2017 John Wiley & Sons, Ltd.

  11. All Prime Contract Awards by State or Country, Place, and Contractor. Part 1 (Addison, Alabama-Yell Arkansas)

    DTIC Science & Technology

    1990-01-01

    0 066f 60 04 61 0 W 00 ɞ if 0 I6 ca IOU 1- -4 at 6(0N1 o2 6 004 1-61)6( 0 61-4 0L L) 0 00 6 Z #1 E1 0 66 it 0 Ll 0.1 00 C 0 2 Oil 5 (a 0 CN N6 z...34n05 I I U)U 0 In ui In - 0 )C0) c) I -r-r- I-. II 5 (-4cinO 47)0C) 0 ) cv) 1- 0 ) 0 ) 0 ) 0 ) -4Ifl U) M’ (OC0( 0 ( 0 I 4M -4 IN0 - - - 1- CD-. 0r - 0 MCI) C’) r...34 I 4’ 5 *t 0 1

  12. Prime Contractors with Awards Over $25,000 by Name, Location, and Contract Number. Part 2 (BAIN MXRARY BAIN-CONSOLIDATED PRODUCTS CORP)

    DTIC Science & Technology

    1990-01-01

    5’ -DOF t’- -- F 0 M C)0 co loc. ’m toF mN NO NO F o w r-44( cu 4) 04- F00 0FO0F 0 0 F 3: u) F.F I >z zL)L UL CL F C’ CFF 0 F FO F CC . ~~FF ’-F aF ...0 ot 0 I-L o oL 0~~ It<A1 tII <( , Ca 4 .,wt u m 0 z Hmm m0 IMP 4m o z 0 .1 o a)O 0 1 af m~ r-oma I~U im I (I US 0 00 05) I03 d~L.I 0 0jJ𔃾 . 0 0 u...0u a) 04 t -C/. a)C 00w <-t o o. ~ ~ O to~t to0C) LC o 0. Do) CA x )o >o C 0 ) 4g -. u)I z3 - (0 0 -. 0 I . (0 o oo czt 0.. to ClL 0) 0 .0t ) 0 H 0

  13. Stressor-induced increase in muscle fatigability of young men and women is predicted by strength but not voluntary activation

    PubMed Central

    Pereira, Hugo M.; Pruse, Jaclyn; Yoon, Tejin; Schlinder-DeLap, Bonnie; Nielson, Kristy A.; Hunter, Sandra K.

    2014-01-01

    This study investigated mechanisms for the stressor-induced changes in muscle fatigability in men and women. Participants performed an isometric-fatiguing contraction at 20% maximal voluntary contraction (MVC) until failure with the elbow flexor muscles. Study one (n = 55; 29 women) involved two experimental sessions: 1) a high-stressor session that required a difficult mental-math task before and during a fatiguing contraction and 2) a control session with no mental math. For some participants (n = 28; 14 women), cortical stimulation was used to examine mechanisms that contributed to muscle fatigability during the high-stressor and control sessions. Study two (n = 23; nine women) determined the influence of a low stressor, i.e., a simple mental-math task, on muscle fatigability. In study one, the time-to-task failure was less for the high-stressor session than control (P < 0.05) for women (19.4%) and men (9.5%): the sex difference response disappeared when covaried for initial strength (MVC). MVC force, voluntary activation, and peak-twitch amplitude decreased similarly for the control and high-stressor sessions (P < 0.05). In study two, the time-to-task failure of men or women was not influenced by the low stressor (P > 0.05). The greater fatigability, when exposed to a high stressor during a low-force task, was not exclusive to women but involved a strength-related mechanism in both weaker men and women that accelerated declines in voluntary activation and slowing of contractile properties. PMID:24526582

  14. WHEN DID ROUND DISK GALAXIES FORM?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takeuchi, T. M.; Ohta, K.; Yuma, S.

    2015-03-01

    When and how galaxy morphology, such as the disk and bulge seen in the present-day universe, emerged is still not clear. In the universe at z ≳ 2, galaxies with various morphologies are seen, and star-forming galaxies at z ∼ 2 show the intrinsic shape of bar-like structures. Then, when did the round disk structure form? Here we take a simple and straightforward approach to see the epoch when a round disk galaxy population emerged by constraining the intrinsic shape statistically based on the apparent axial ratio distribution of galaxies. We derived the distributions of the apparent axial ratios inmore » the rest-frame optical light (∼5000 Å) of star-forming main-sequence galaxies at 2.5 > z > 1.4, 1.4 > z > 0.85, and 0.85 > z > 0.5, and found that their apparent axial ratios show peaky distributions at z ≳ 0.85, while a rather flat distribution at the lower redshift. By using a tri-axial model (A > B > C) for the intrinsic shape, we found that the best-fit models give the peaks of the B/A distribution of 0.81 ± 0.04, 0.84 ± 0.04, and 0.92 ± 0.05 at 2.5 > z > 1.4, 1.4 > z > 0.85, and 0.85 > z > 0.5, respectively. The last value is close to the local value of 0.95. Thickness (C/A) is ∼0.25 at all the redshifts and is close to the local value (0.21). The results indicate that the shape of the star-forming galaxies in the main sequence changes gradually, and that the round disk is established at around z ∼ 0.9. The establishment of the round disk may be due to the cessation of a violent interaction between galaxies or the growth of a bulge and/or a supermassive black hole residing at the center of a galaxy that dissolves the bar structure.« less

  15. Long-timescale molecular dynamics simulations elucidate the dynamics and kinetics of exposure of the hydrophobic patch in troponin C.

    PubMed

    Lindert, Steffen; Kekenes-Huskey, Peter M; McCammon, J Andrew

    2012-10-17

    Troponin (Tn) is an important regulatory protein in the thin-filament complex of cardiomyocytes. Calcium binding to the troponin C (TnC) subunit causes a change in its dynamics that leads to the transient opening of a hydrophobic patch on TnC's surface, to which a helix of another subunit, troponin I (TnI), binds. This process initiates contraction, making it an important target for studies investigating the detailed molecular processes that underlie contraction. Here we use microsecond-timescale Anton molecular dynamics simulations to investigate the dynamics and kinetics of the opening transition of the TnC hydrophobic patch. Free-energy differences for opening are calculated for wild-type Ca(2+)-bound TnC (∼8 kcal/mol), V44Q Ca(2+)-bound TnC (3.2 kcal/mol), E40A Ca(2+)-bound TnC (∼12 kcal/mol), and wild-type apo TnC (∼20 kcal/mol). These results suggest that the mutations have a profound impact on the frequency with which the hydrophobic patch presents to TnI. In addition, these simulations corroborate that cardiac wild-type TnC does not open on timescales relevant to contraction without calcium being bound. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Sarcomere mechanics in uniform and non-uniform cardiac muscle: a link between pump function and arrhythmias.

    PubMed

    ter Keurs, Henk E D J; Shinozaki, Tsuyoshi; Zhang, Ying Ming; Zhang, Mei Luo; Wakayama, Yuji; Sugai, Yoshinao; Kagaya, Yutaka; Miura, Masahito; Boyden, Penelope A; Stuyvers, Bruno D M; Landesberg, Amir

    2008-01-01

    Starling's Law and the well-known end-systolic pressure-volume relationship (ESPVR) of the left ventricle reflect the effect of sarcomere length (SL) on stress (sigma) development and shortening by myocytes in the uniform ventricle. We show here that tetanic contractions of rat cardiac trabeculae exhibit a sigma-SL relationship at saturating [Ca2+] that depends on sarcomere geometry in a manner similar to skeletal sarcomeres and the existence of opposing forces in cardiac muscle shortened below slack length. The sigma-SL-[Ca2+]free relationships (sigma-SL-CaR) at submaximal [Ca2+] in intact and skinned trabeculae were similar, albeit that the sensitivity for Ca2+ of intact muscle was higher. We analyzed the mechanisms underlying the sigma-SL-CaR using a kinetic model where we assumed that the rates of Ca2+ binding by Troponin-C (Tn-C) and/or cross-bridge (XB) cycling are determined by SL, [Ca2+] or stress. We analyzed the correlation between the model results and steady state stress measurements at varied SL and [Ca2+] from skinned rat cardiac trabeculae to test the hypotheses that: (i) the dominant feedback mechanism is SL, stress or [Ca2+]-dependent; and (ii) the feedback mechanism regulates: Tn-C-Ca2+ affinity, XB kinetics or, unitary XB-force. The analysis strongly suggests that feedback of the number of strong XBs to cardiac Tn-C-Ca2+ affinity is the dominant mechanism that regulates XB recruitment. Application of this concept in a mathematical model of twitch-stress accurately reproduced the sigma-SL-CaR and the time course of twitch-stress as well as the time course of intracellular [Ca2+]i. Modeling of the response of the cardiac twitch to rapid stress changes using the above feedback model uniquely predicted the occurrence of [Ca2+]i transients as a result of accelerated Ca2+ dissociation from Tn-C. The above concept has important repercussions for the non-uniformly contracting heart in which arrhythmogenic Ca2+ waves arise from weakened areas in cardiac muscle. These Ca2+ waves can reversibly be induced in muscle with non-uniform excitation contraction coupling (ECC) by the cycle of stretch and release in the border zone between the damaged and intact regions. Stimulus trains induced propagating Ca2+ waves and reversibly induced arrhythmias. We hypothesize that rapid force loss by sarcomeres in the border zone during relaxation causes Ca2+ release from Tn-C and initiates Ca2+ waves propagated by the sarcoplasmic reticulum (SR). These observations suggest the unifying hypothesis that force feedback to Ca2+ binding by Tn-C is responsible for Starling's Law and the ESPVR in uniform myocardium and leads in non-uniform myocardium to a surge of Ca2+ released by the myofilaments during relaxation, which initiates arrhythmogenic propagating Ca2+ release by the SR.

  17. Ca2+-regulated-cAMP/PKA signaling in cardiac pacemaker cells links ATP supply to demand.

    PubMed

    Yaniv, Yael; Juhaszova, Magdalena; Lyashkov, Alexey E; Spurgeon, Harold A; Sollott, Steven J; Lakatta, Edward G

    2011-11-01

    In sinoatrial node cells (SANC), Ca(2+) activates adenylate cyclase (AC) to generate a high basal level of cAMP-mediated/protein kinase A (PKA)-dependent phosphorylation of Ca(2+) cycling proteins. These result in spontaneous sarcoplasmic-reticulum (SR) generated rhythmic Ca(2+) oscillations during diastolic depolarization, that not only trigger the surface membrane to generate rhythmic action potentials (APs), but, in a feed-forward manner, also activate AC/PKA signaling. ATP is consumed to pump Ca(2+) to the SR, to produce cAMP, to support contraction and to maintain cell ionic homeostasis. Since feedback mechanisms link ATP-demand to ATP production, we hypothesized that (1) both basal ATP supply and demand in SANC would be Ca(2+)-cAMP/PKA dependent; and (2) due to its feed-forward nature, a decrease in flux through the Ca(2+)-cAMP/PKA signaling axis will reduce the basal ATP production rate. O(2) consumption in spontaneous beating SANC was comparable to ventricular myocytes (VM) stimulated at 3 Hz. Graded reduction of basal Ca(2+)-cAMP/PKA signaling to reduce ATP demand in rabbit SANC produced graded ATP depletion (r(2)=0.96), and reduced O(2) consumption and flavoprotein fluorescence. Neither inhibition of glycolysis, selectively blocking contraction nor specific inhibition of mitochondrial Ca(2+) flux reduced the ATP level. Feed-forward basal Ca(2+)-cAMP/PKA signaling both consumes ATP to drive spontaneous APs in SANC and is tightly linked to mitochondrial ATP production. Interfering with Ca(2+)-cAMP/PKA signaling not only slows the firing rate and reduces ATP consumption, but also appears to reduce ATP production so that ATP levels fall. This distinctly differs from VM, which lack this feed-forward basal cAMP/PKA signaling, and in which ATP level remains constant when the demand changes. Published by Elsevier Ltd.

  18. [Effects of nitric oxide on peritoneal lymphatic stomata and lymph drainage via NO-cGMP-Ca2+ pathway].

    PubMed

    Li, Yan-Yuan; Li, Ji-Cheng

    2005-02-25

    To study the cell signal transduction mechanism of nitric oxide (NO) on the peritoneal lymphatic stomata and lymph drainage in the rat, cGMP content were measured by a commercially available radioimmunoassay kit, and the [Ca(2+)](i) were observed by a confocal laser scanning microscope in the cultured peritoneal mesothelial cell. Animal experiment was practiced to study the effect of NO-cGMP-Ca(2+) pathway on the lymphatic stomata and lymph absorption. The results showed that: (1) Sper/NO increased cGMP of the rat peritoneal mesothelial cell (RPMC) in a dose-dependent manner (P<0.01) compared to the control group. This effect was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (P<0.05), a specific inhibitor of soluble guanylyl cyclase (sGC). The level of [Ca(2+)](i) in single RPMC decreased by adding Sper/NO (P<0.05). Pretreatment with ODQ for 10 min blocked the Sper/NO-induced decrease in [Ca(2+)](i). L-typed calcium channel blocker nifedipine induced an immediate and marked decrease in [Ca(2+)](i) (P<0.05).. After [Ca(2+)](i) reached a balance again, adding Sper/NO could not change [Ca(2+)](i) (P>0.05). (2) Sper/NO increased the area of the stomata (P<0.01) and the quantity of the tracer in a dose-dependent manner (P<0.05) compared to the control group. Pretreatment with ODQ significantly inhibited Sper/NO-induced change of lymphatic stomata and lymph drainage (P<0.01). Nifedipine increased the opening area of the lymphatic stomata (P< 0.01) and the concentration of absorbed trypan blue of the diaphragm (P<0.05). Sper/NO could not make a further change in the samples pretreated by nifedipine (P> 0.05). The results indicate that NO can decrease [Ca(2+)](i) in the RPMC through the NO-cGMP pathway. This procession is related with the L- type voltage-gated Ca(2+) channel. NO enlarges the opening area of the lymphatic stomata and enhances the lymph drainage of tracer by NO-cGMP-[Ca(2+)](i) pathway.

  19. Role of guanine nucleotide-binding proteins--ras-family or trimeric proteins or both--in Ca2+ sensitization of smooth muscle.

    PubMed Central

    Gong, M C; Iizuka, K; Nixon, G; Browne, J P; Hall, A; Eccleston, J F; Sugai, M; Kobayashi, S; Somlyo, A V; Somlyo, A P

    1996-01-01

    The purpose of this study was to identify guanine nucleotide-binding proteins (G proteins) involved in the agonist- and guanosine 5'-[gamma-thio]triphosphate (GTP[gamma-S])-induced increase in the Ca2+ sensitivity of 20-kDa myosin light chain (MLC20) phosphorylation and contraction in smooth muscle. A constitutively active, recombinant val14p21rhoA.GTP expressed in the baculovirus/Sf9 system, but not the protein expressed without posttranslational modification in Escherichia coli, induced at constant Ca2+ (pCa 6.4) a slow contraction associated with increased MLC20 phosphorylation from 19.8% to 29.5% (P < 0.05) in smooth muscle permeabilized with beta-esein. The effect of val14p21rhoA.GTP was inhibited by ADP-ribosylation of the protein and was absent in smooth muscle extensively permeabilized with Triton X-100. ADP-ribosylation of endogenous p21rho with epidermal cell differentiation inhibitor (EDIN) inhibited Ca2+ sensitization induced by GTP [in rabbit mesenteric artery (RMA) and rabbit ileum smooth muscles], by carbachol (in rabbit ileum), and by endothelin (in RMA), but not by phenylephrine (in RMA), and only slowed the rate without reducing the amplitude of contractions induced in RMA by 1 microM GTP[gamma-S] at constant Ca2+ concentrations. AlF(4-)-induced Ca2+ sensitization was inhibited by both guanosine 5'-[beta-thio]diphosphate (GDP[beta-S]) and by EDIN. EDIN also inhibited, to a lesser extent, contractions induced by Ca2+ alone (pCa 6.4) in both RMA and rabbit ileum. ADP-ribosylation of trimeric G proteins with pertussis toxin did not inhibit Ca2+ sensitization. We conclude that p21rho may play a role in physiological Ca2+ sensitization as a cofactor with other messengers, rather than as a sole direct inhibitor of smooth muscle MLC20 phosphatase. Images Fig. 3 Fig. 4 PMID:8577766

  20. Crystal structure of 2-((1E)-{2-[bis-(2-methyl-benzyl-sulfan-yl)methyl-idene]hydrazin-1-yl-idene}meth-yl)-6-meth-oxy-phenol.

    PubMed

    Yusof, Enis Nadia Md; Ravoof, Thahira Begum S A; Tahir, Mohamed Ibrahim Mohamed; Tiekink, Edward R T

    2015-04-01

    In the title compound, C25H26N2O2S2, the central CN2S2 atoms are almost coplanar (r.m.s. deviation = 0.0058 Å). One phenyl ring clearly lies to one side of the central plane, while the other is oriented in the plane but splayed. Despite the different relative orientations, the phenyl rings form similar dihedral angles of 64.90 (3) and 70.06 (3)° with the central plane, and 63.28 (4)° with each other. The benzene ring is twisted with respect to the central plane, forming a dihedral angle of 13.17 (7)°. The S2C=N, N-N and N-N=C bond lengths of 1.2919 (19), 1.4037 (17) and 1.2892 (19) Å, respectively, suggest limited conjugation over these atoms; the configuration about the N-N=C bond is E. An intra-molecular O-H⋯N hydrogen bond is noted. In the crystal, phen-yl-meth-oxy C-H⋯O and phen-yl-phenyl C-H⋯π inter-actions lead to supra-molecular double chains parallel to the b axis. These are connected into a layer via meth-yl-phenyl C-H⋯π inter-actions, and layers stack along the a axis, being connected by weak π-π inter-actions between phenyl rings [inter-centroid distance = 3.9915 (9) Å] so that a three-dimensional architecture ensues.

  1. A computational model of the ionic currents, Ca2+ dynamics and action potentials underlying contraction of isolated uterine smooth muscle.

    PubMed

    Tong, Wing-Chiu; Choi, Cecilia Y; Kharche, Sanjay; Karche, Sanjay; Holden, Arun V; Zhang, Henggui; Taggart, Michael J

    2011-04-29

    Uterine contractions during labor are discretely regulated by rhythmic action potentials (AP) of varying duration and form that serve to determine calcium-dependent force production. We have employed a computational biology approach to develop a fuller understanding of the complexity of excitation-contraction (E-C) coupling of uterine smooth muscle cells (USMC). Our overall aim is to establish a mathematical platform of sufficient biophysical detail to quantitatively describe known uterine E-C coupling parameters and thereby inform future empirical investigations of physiological and pathophysiological mechanisms governing normal and dysfunctional labors. From published and unpublished data we construct mathematical models for fourteen ionic currents of USMCs: Ca2+ currents (L- and T-type), Na+ current, an hyperpolarization-activated current, three voltage-gated K+ currents, two Ca2+-activated K+ current, Ca2+-activated Cl current, non-specific cation current, Na+-Ca2+ exchanger, Na+-K+ pump and background current. The magnitudes and kinetics of each current system in a spindle shaped single cell with a specified surface area:volume ratio is described by differential equations, in terms of maximal conductances, electrochemical gradient, voltage-dependent activation/inactivation gating variables and temporal changes in intracellular Ca2+ computed from known Ca2+ fluxes. These quantifications are validated by the reconstruction of the individual experimental ionic currents obtained under voltage-clamp. Phasic contraction is modeled in relation to the time constant of changing [Ca2+]i. This integrated model is validated by its reconstruction of the different USMC AP configurations (spikes, plateau and bursts of spikes), the change from bursting to plateau type AP produced by estradiol and of simultaneous experimental recordings of spontaneous AP, [Ca2+]i and phasic force. In summary, our advanced mathematical model provides a powerful tool to investigate the physiological ionic mechanisms underlying the genesis of uterine electrical E-C coupling of labor and parturition. This will furnish the evolution of descriptive and predictive quantitative models of myometrial electrogenesis at the whole cell and tissue levels.

  2. A new series of oxycarbonate superconductors (Cu(0.5)C(0.5))(m)Ba(m+1)Ca(n-1)Cu(n)O2(m+n)+1

    NASA Technical Reports Server (NTRS)

    Takayama-Muromachi, E.; Kawashima, T.; Matsui, Y.

    1995-01-01

    We found a new series of oxycarbonate superconductors in the Ba-CaCu-C-O system under high pressure of 5 GPa. Their ideal formula is (Cu(0.5)C(0.5)(m)Ba(m+1)Ca(n-1)Cu(n)O2)((m+n)+1) ((Cu,C)-m(m+1)(n-1)n). Thus far, n = 3, 4 members of the m = 1 series, (Cu,C)-1223 and (Cu,C)-1234, have been prepared in bulk while n = 4, 5 members, (Cu,C)-2334 and (Cu,C)-2345, have been prepared for the m = 2 series. (Cu,C)-1223 shows superconductivity below 67 K while T(sub c)'s of other compounds are above 110 K. In particular, (Cu,C)-1234 has the highest T(sub c) of 117 K.

  3. Modulation of subthalamic T-type Ca2+ channels remedies locomotor deficits in a rat model of Parkinson disease

    PubMed Central

    Tai, Chun-Hwei; Yang, Ya-Chin; Pan, Ming-Kai; Huang, Chen-Syuan; Kuo, Chung-Chin

    2011-01-01

    An increase in neuronal burst activities in the subthalamic nucleus (STN) is a well-documented electrophysiological feature of Parkinson disease (PD). However, the causal relationship between subthalamic bursts and PD symptoms and the ionic mechanisms underlying the bursts remain to be established. Here, we have shown that T-type Ca2+ channels are necessary for subthalamic burst firing and that pharmacological blockade of T-type Ca2+ channels reduces motor deficits in a rat model of PD. Ni2+, mibefradil, NNC 55-0396, and efonidipine, which inhibited T-type Ca2+ currents in acutely dissociated STN neurons, but not Cd2+ and nifedipine, which preferentially inhibited L-type or the other non–T-type Ca2+ currents, effectively diminished burst activity in STN slices. Topical administration of inhibitors of T-type Ca2+ channels decreased in vivo STN burst activity and dramatically reduced the locomotor deficits in a rat model of PD. Cd2+ and nifedipine showed no such electrophysiological and behavioral effects. While low-frequency deep brain stimulation (DBS) has been considered ineffective in PD, we found that lengthening the duration of the low-frequency depolarizing pulse effectively improved behavioral measures of locomotion in the rat model of PD, presumably by decreasing the availability of T-type Ca2+ channels. We therefore conclude that modulation of subthalamic T-type Ca2+ currents and consequent burst discharges may provide new strategies for the treatment of PD. PMID:21737877

  4. The effects of muscle contraction and recombinant osteocalcin on insulin sensitivity ex vivo.

    PubMed

    Levinger, I; Lin, X; Zhang, X; Brennan-Speranza, T C; Volpato, B; Hayes, A; Jerums, G; Seeman, E; McConell, G

    2016-02-01

    We tested whether GPRC6A, the putative receptor of undercarboxylated osteocalcin (ucOC), is present in mouse muscle and whether ucOC increases insulin sensitivity following ex vivo muscle contraction. GPPRC6A is expressed in mouse muscle and in the mouse myotubes from a cell line. ucOC potentiated the effect of ex vivo contraction on insulin sensitivity. Acute exercise increases skeletal muscle insulin sensitivity. In humans, exercise increases circulating ucOC, a hormone that increases insulin sensitivity in rodents. We tested whether GPRC6A, the putative receptor of ucOC, is present in mouse muscle and whether recombinant ucOC increases insulin sensitivity in both C2C12 myotubes and whole mouse muscle following ex vivo muscle contraction. Glucose uptake was examined in C2C12 myotubes that express GPRC6A following treatment with insulin alone or with insulin and increasing ucOC concentrations (0.3, 3, 10 and 30 ng/ml). In addition, glucose uptake, phosphorylated (p-)AKT and p-AS160 were examined ex vivo in extensor digitorum longus (EDL) dissected from C57BL/6J wild-type mice, at rest, following insulin alone, after muscle contraction followed by insulin and after muscle contraction followed by recombinant ucOC then insulin exposure. We observed protein expression of the likely receptor for ucOC, GPRC6A, in whole muscle sections and differentiated mouse myotubes. We observed reduced GPRC6A expression following siRNA transfection. ucOC significantly increased insulin-stimulated glucose uptake dose-dependently up to 10 ng/ml, in differentiated mouse C2C12 myotubes. Insulin increased EDL glucose uptake (∼30 %, p < 0.05) and p-AKT and p-AKT/AKT compared with rest (all p < 0.05). Contraction prior to insulin increased muscle glucose uptake (∼25 %, p < 0.05), p-AKT, p-AKT/AKT, p-AS160 and p-AS160/AS160 compared with contraction alone (all p < 0.05). ucOC after contraction increased insulin-stimulated muscle glucose uptake (∼12 % p < 0.05) and p-AS160 (<0.05) more than contraction plus insulin alone but without effect on p-AKT. In the absence of insulin and/or of contraction, ucOC had no significant effect on muscle glucose uptake. GPRC6A, the likely receptor of osteocalcin (OC), is expressed in mouse muscle. ucOC treatment augments insulin-stimulated skeletal muscle glucose uptake in C2C12 myotubes and following ex vivo muscle contraction. ucOC may partly account for the insulin sensitizing effect of exercise.

  5. Older men are more fatigable than young when matched for maximal power and knee extension angular velocity is unconstrained.

    PubMed

    Dalton, Brian H; Power, Geoffrey A; Paturel, Justin R; Rice, Charles L

    2015-06-01

    The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque-power relationships were constructed prior to and following both fatiguing tasks and during short-term recovery. Contractile properties were recorded from 9 old (~75 years) and 11 young (~25 years) men during three testing sessions. In the first session, maximal power was assessed, and sessions 2 and 3 involved an isokinetic or an isotonic concentric fatigue task performed until maximal power was reduced by 40 %. Compared with young, the older men performed the same number of contractions to task failure for the isokinetic task (~45 contractions), but 20 % fewer for the isotonic task (p < 0.05). Regardless of age and task, maximal voluntary isometric contraction strength, angular velocity, and power were reduced by ~30, ~13, and ~25 %, respectively, immediately following task failure, and only isometric torque was not recovered fully by 10 min. In conclusion, older men are more fatigable than the young when performing a repetitive maximal dynamic task at a relative resistance (isotonic) but not an absolute velocity (isokinetic), corresponding to maximal power.

  6. Effects of modulators of AMP-activated protein kinase on TASK-1/3 and intracellular Ca(2+) concentration in rat carotid body glomus cells.

    PubMed

    Kim, Donghee; Kang, Dawon; Martin, Elizabeth A; Kim, Insook; Carroll, John L

    2014-05-01

    Acute hypoxia depolarizes carotid body chemoreceptor (glomus) cells and elevates intracellular Ca(2+) concentration ([Ca(2+)]i). Recent studies suggest that AMP-activated protein kinase (AMPK) mediates these effects of hypoxia by inhibiting the background K(+) channels such as TASK. Here we studied the effects of modulators of AMPK on TASK activity in cell-attached patches. Activators of AMPK (1mM AICAR and 0.1-0.5mM A769662) did not inhibit TASK activity or cause depolarization during acute (10min) or prolonged (2-3h) exposure. Hypoxia inhibited TASK activity by ∼70% in cells pretreated with AICAR or A769662. Both AICAR and A769662 (15-40min) failed to increase [Ca(2+)]i in glomus cells. Compound C (40μM), an inhibitor of AMPK, showed no effect on hypoxia-induced inhibition of TASK. AICAR and A769662 phosphorylated AMPKα in PC12 cells, and Compound C blocked the phosphorylation. Our results suggest that AMPK does not affect TASK activity and is not involved in hypoxia-induced elevation of intracellular [Ca(2+)] in isolated rat carotid body glomus cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Decreased cardiac SERCA2 expression, SR Ca uptake, and contractile function in hypothyroidism are attenuated in SERCA2 overexpressing transgenic rats.

    PubMed

    Vetter, Roland; Rehfeld, Uwe; Reissfelder, Christoph; Fechner, Henry; Seppet, Enn; Kreutz, Reinhold

    2011-03-01

    The sarco/endoplasmic reticulum (SR) Ca(2+)-ATPase SERCA2a has a key role in controlling cardiac contraction and relaxation. In hypothyroidism, decreased expression of the thyroid hormone (TH)-responsive SERCA2 gene contributes to slowed SR Ca(2+) reuptake and relaxation. We investigated whether cardiac expression of a TH-insensitive SERCA2a cDNA minigene can rescue SR Ca(2+) handling and contractile function in female SERCA2a-transgenic rats (TG) with experimental hypothyroidism. Wild-type rats (WT) and TG were rendered hypothyroid by 6-N-propyl-2-thiouracil treatment for 6 wk; control rats received no treatment. In vivo measured left ventricular (LV) hemodynamic parameters were compared with SERCA2a expression and function in LV tissue. Hypothyroidism decreased LV peak systolic pressure, dP/dt(max), and dP/dt(min) in both WT and TG. However, loss of function was less in TG. Thus slowed relaxation in hypothyroidism was found to be 1.5-fold faster in TG compared with WT (P < 0.05). In parallel, a 1.4-fold higher V(max) value of homogenate SR Ca(2+) uptake was observed in hypothyroid TG (P < 0.05 vs. hypothyroid WT), and the hypothyroidism-caused decline of LV SERCA2a mRNA expression in TG by -24% was markedly less than the decrease of -49% in WT (P < 0.05). A linear relationship was observed between the SERCA2a/PLB mRNA ratio values and the V(max) values of SR Ca(2+) uptake when the respective data of all experimental groups were plotted together (r = 0.90). The data show that expression of the TH-insensitive SERCA2a minigene compensates for loss of expressional activity of the TH-responsive native SERCA2a gene in the female hypothyroid rat heart. However, SR Ca(2+) uptake and in vivo heart function were only partially rescued.

  8. The association of interleukin-10 -1082, -819, -592 polymorphisms and tuberculosis risk.

    PubMed

    Liu, Qianqian; Li, Wenzhang; Li, Dongdong; Feng, Yulin; Tao, Chuanmin

    2015-04-01

    To assess the association between interleukin (IL)-10 -1082, -819, -592 polymorphisms and tuberculosis (TB) risk. This study was conducted between July and October 2014 in West China Hospital, Chengdu, Sichuan, China. We searched and collected data from PUBMED, EMBASE, Web of Science, China National Knowledge Infrastructure, VIP, and WANGFANG up to October 2014. A total of 37 studies were enrolled, including 8625 TB cases, and 9928 healthy controls. The IL-10-1082G/A polymorphism was found to be associated with TB susceptibility in Caucasian (GG versus GA+AA, odds ratio [OR] - 1.83, 95% confidence interval [CI] - 1.03-3.24). The IL-10-819C/T polymorphism was related to TB susceptibility among Asians (C versus T, OR - 0.88, 95% CI - 0.81-0.97; CC versus TT: OR - 0.79, 95% CI - 0.64-0.97; CC+CT versus TT: OR - 0.87, 95% CI - 0.77-0.98; CC versus CT+TT: OR - 0.82, 95% CI - 0.68-0.98). The IL-10-592C/A polymorphism was in association with TB susceptibility in Asians (C versus A: OR - 0.74, 95% CI - 0.65-0.85; CC versus AA: OR - 0.55, 95% CI - 0.41-0.75; CA versus AA: OR - 0.73, 95% CI - 0.60-0.89; CC+CA versus AA: OR - 0.69, 95% CI 0.58-0.83; CA versus AA: OR - 0.66, 95% CI 0.51-0.86), Caucasian (C versus A: OR - 1.25, 95% CI - 1.08-1.45; CC versus CA+AA: OR-1.48, 95% CI - 1.16-1.89), and Europeans (C versus A: OR - 1.31, 95% CI - 1.02-1.67; CC versus AA: OR - 1.88, 95% CI - 1.05-3.37). This meta-analysis suggests that IL-10-1082G/A, IL-819C/T, and IL-592C/A polymorphisms might be associated with TB susceptibility in certain ethnicities.

  9. [Effects of genistein on contractility of isolated right ventricular muscles in guinea pig].

    PubMed

    Wu, Jin-xia; Li, Hong-fang; Liu, Chong-bin; Tian, Zhi-feng

    2008-11-01

    To study the effect of genistein (GEN) on contractility of isolated right ventricular muscles in guinea pig and its mechanisms. Isolated guinea pig ventricular muscles were suspended in organ baths containing K-H solution.After an equilibration period, the effect of GEN on contraction of myocardium was observed. GEN and isoprenaline hydrochloride had the positive inotropic effects on contractity of myocardium. Meanwhile, the effect of GEN (1-100 micromol x L(-1)) was in dose-dependent manner. Propranolol (1 micromol x L(-1)) and verapamil hydrochloride (0.5 micromol x L(-1)) attenuated the positive inotropic effect of isoprenaline hydrochloride (1 micromol x L(-1)), but did not change the effect of GEN (50 micromol x L(-1)). Further more, the enhancement of the contraction induced by elevation of extracellular Ca2+ concentration in ventricular muscles had no change after pretreatment with GEN (1.10 micromol x L(-1)). In addition,the positive inotropic effect of GEN was inhibited partially by tamoxifen (1 micromol x L(-1)) and SQ22536 (1 micromol x L(-1)), also, could be attenuated by bpV (1 micromol x L(-1)). GEN has the positive inotropic effect on guinea pig ventricular muscles, which is not related to the activation of beta adrenoceptor, Ca2+ channel on cell membrane,but may involve in cAMP of intracellular signal transduction and tyrosine kinase pathway.

  10. Predominant cause of prolonged low-frequency force depression changes during recovery after in situ fatiguing stimulation of rat fast-twitch muscle.

    PubMed

    Watanabe, Daiki; Wada, Masanobu

    2016-11-01

    To investigate time-dependent changes in sarcoplasmic reticulum (SR) Ca 2+ release and myofibrillar (my-) Ca 2+ sensitivity during recovery from prolonged low-frequency force depression (PLFFD), rat gastrocnemius muscles were electrically stimulated in situ. After 0 h (R0), 0.5 h (R0.5), 2 h (R2), 6 h (R6), or 12 h of recovery, the superficial gastrocnemius muscles were excised and used for biochemical and skinned fiber analyses. At R0, R0.5, R2, and R6, the ratio of force at 1 Hz to that at 50 Hz was decreased in the skinned fibers. The ratio of depolarization-induced force to the maximum Ca 2+ -activated force (depol/Ca 2+ force ratio) was utilized as an indicator of SR Ca 2+ release. At R0, both the depol/Ca 2+ force ratio and my-Ca 2+ sensitivity were decreased. At R0.5 and R2, my-Ca 2+ sensitivity was recovered, while the depol/Ca 2+ force ratio remained depressed. At R6, my-Ca 2+ sensitivity was decreased again, whereas the depol/Ca 2+ force ratio was nearly restored. Western blot analyses demonstrated that decreased my-Ca 2+ sensitivity at R6 and reduced depol/Ca 2+ force ratio at R0, R0.5, and R2 were accompanied by depressions in S-glutathionylated troponin I and increases in dephosphorylated ryanodine receptor 1, respectively. These results indicate that, in the early stage of recovery, reduced SR Ca 2+ release plays a primary role in the etiology of PLFFD, whereas decreased my-Ca 2+ sensitivity is involved in the late stage, and suggest that S-glutathionylation of troponin I and dephosphorylation of ryanodine receptor 1 contribute, at least partly, to fatiguing contraction-induced alterations in my-Ca 2+ sensitivity and SR Ca 2+ release, respectively. Copyright © 2016 the American Physiological Society.

  11. Glass for sealing lithium cells

    DOEpatents

    Leedecke, C.J.

    1981-08-28

    Glass compositions resistant to corrosion by lithium cell electrolyte and having an expansion coefficient of 45 to 85 x 10/sup -70/C/sup -1/ have been made with SiO/sub 2/, 25 to 55% by weight; B/sub 2/O/sub 3/, 5 to 12%; Al/sub 2/O/sub 3/, 12 to 35%; CaO, 5 to 15%; MgO, 5 to 15%; SrO, 0 to 10%; and La/sub 2/O/sub 3/, 0 to 5%. Preferred compositions within that range contain 3 to 8% SrO and 0.5 to 2.5% La/sub 2/O/sub 3/.

  12. Ca(2+)-channel blockade in rat thoracic aorta by protopine isolated from Corydalis tubers.

    PubMed

    Ko, F N; Wu, T S; Lu, S T; Wu, Y C; Huang, T F; Teng, C M

    1992-01-01

    The pharmacological properties and mechanism of the action of protopine on isolated rat thoracic aorta were examined. It inhibited norepinephrine (NE, 3 microM)-induced tonic contraction in rat thoracic aorta in a concentration-dependent manner (25-100 micrograms/ml). The phasic contraction caused by NE was inhibited only by a high concentration of protopine (100 micrograms/ml). At the plateau of NE-induced tonic contraction, the addition of protopine also caused relaxation. This relaxing effect of protopine was not antagonized by indomethacin (20 microM) or methylene blue (50 microM), and it still existed in denuded rat aorta or in the presence of nifedipine (2-100 microM). Protopine also inhibited high potassium (60 mM)-induced, calcium-dependent (0.03-3 mM) contraction of rat aorta in a concentration-dependent manner. Neither cAMP nor cGMP level was changed by protopine. Both the formation of inositol monophosphate caused by NE and the phasic contraction induced by caffeine were also not affected by protopine. 45Ca2+ influx caused by either NE or K+ was inhibited by protopine concentration-dependently. It is concluded that protopine relaxed the rat thoracic aorta mainly by suppressing the Ca2+ influx through both voltage- and receptor-operated calcium channels.

  13. Type-3 ryanodine receptors mediate hypoxia-, but not neurotransmitter-induced calcium release and contraction in pulmonary artery smooth muscle cells.

    PubMed

    Zheng, Yun-Min; Wang, Qing-Song; Rathore, Rakesh; Zhang, Wan-Hui; Mazurkiewicz, Joseph E; Sorrentino, Vincenzo; Singer, Harold A; Kotlikoff, Michael I; Wang, Yong-Xiao

    2005-04-01

    In this study we examined the expression of RyR subtypes and the role of RyRs in neurotransmitter- and hypoxia-induced Ca2+ release and contraction in pulmonary artery smooth muscle cells (PASMCs). Under perforated patch clamp conditions, maximal activation of RyRs with caffeine or inositol triphosphate receptors (IP3Rs) with noradrenaline induced equivalent increases in [Ca2+]i and Ca2+-activated Cl- currents in freshly isolated rat PASMCs. Following maximal IP3-induced Ca2+ release, neither caffeine nor chloro-m-cresol induced a response, whereas prior application of caffeine or chloro-m-cresol blocked IP3-induced Ca2+ release. In cultured human PASMCs, which lack functional expression of RyRs, caffeine failed to affect ATP-induced increases in [Ca2+]i in the presence and absence of extracellular Ca2+. The RyR antagonists ruthenium red, ryanodine, tetracaine, and dantrolene greatly inhibited submaximal noradrenaline- and hypoxia-induced Ca2+ release and contraction in freshly isolated rat PASMCs, but did not affect ATP-induced Ca2+ release in cultured human PASMCs. Real-time quantitative RT-PCR and immunofluorescence staining indicated similar expression of all three RyR subtypes (RyR1, RyR2, and RyR3) in freshly isolated rat PASMCs. In freshly isolated PASMCs from RyR3 knockout (RyR3-/-) mice, hypoxia-induced, but not submaximal noradrenaline-induced, Ca2+ release and contraction were significantly reduced. Ruthenium red and tetracaine can further inhibit hypoxic increase in [Ca2+]i in RyR3-/- mouse PASMCs. Collectively, our data suggest that (a) RyRs play an important role in submaximal noradrenaline- and hypoxia-induced Ca2+ release and contraction; (b) all three subtype RyRs are expressed; and (c) RyR3 gene knockout significantly inhibits hypoxia-, but not submaximal noradrenaline-induced Ca2+ and contractile responses in PASMCs.

  14. Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, FY 85. Part 13 (Mabco Prefabricated Bldg -Middletown Leather Co In).

    DTIC Science & Technology

    1985-01-01

    04 C4 I4 C4I CNN NNN M.4f * N N N -4 -I .4 II.4NN *>-I w- C .40 C t In I, 0 I 1IC w040000oN 0 C4 . I CL 0. 0CZ in WI I )M nMI nIinn 00 CO(-ic.) I enC ...m I1 cNNL N ENC ’ 00 N N) N4 0(n MCI I C) 4 I -000r4 0 *.-0.- N~0 COJ cm mOi cl j C4 CMcj I ~ C)N NN 4~ Il N-.I-0I- 54-0 4 IU-4 1.I 4.I (I 4N - I ca c...40o 3X0 EN ENC , 3N 0 o-4 I-- EN" 0-4 1-400 MI 4 MO m)-I No 0 4- 0) (0 40 co In (o aU’Do Ml) 0 0 00 -4 -4 0 0 0 0 0 0 0 0 440)t M4 I n In In Ln -f 4 U

  15. Modification of rat detrusor muscle contraction by ascorbic acid and citric acid involving enhanced neurotransmitter release and Ca2+ influx.

    PubMed

    Dasgupta, Jaydip; Elliott, Ruth A; Tincello, Douglas G

    2009-01-01

    Consumption of carbonated soft drinks is independently associated with the development of overactive bladder (OR 1.41, 95% Cl 1.02-1.95). We have shown previously that artificial sweeteners, present in carbonated soft drinks, enhanced detrusor muscle contraction. Other constituents of soft drinks are preservatives and antioxidants, we evaluated the effects of two of these, ascorbic acid and citric acid, on the contractile response of isolated rat bladder muscle strips. Detrusor muscle strips were suspended in a perfusion organ bath. We determined the effect of ascorbic acid and citric acid on the contractile responses to electrical field stimulation (EFS) in the absence and presence of atropine, carbachol, alpha, beta methylene ATP, potassium and calcium. Ascorbic acid and citric acid (10(-7) M to 10(-3) M) enhanced the contractile response to 10 Hz EFS compared to control (P < 0.01). The frequency and amplitude of spontaneous bladder contractions were enhanced in the presence of ascorbic acid and citric acid by 14%, 21%, 21%, and 11% respectively. Ascorbic acid 10(-4) M significantly increased the atropine resistant response to EFS 5 Hz by 37% (P < 0.01) and inhibited contraction in response to carbachol 10(-4) M by 24%, (P < 0.05). Both ascorbic acid 10(-4) M and citric acid 10(-5) M significantly enhanced maximum contractile responses to alpha, beta methylene ATP, KCI and calcium compared to control. Ascorbic acid and citric acid augmented bladder muscle contraction possibly by enhanced Ca(2+) influx. Presynaptic neurotransmitter release was enhanced by ascorbic acid. Carbonated beverages containing preservatives may aggravate symptoms of OAB. (c) 2009 Wiley-Liss, Inc.

  16. Dye decolorization and detoxification potential of Ca-alginate beads immobilized manganese peroxidase.

    PubMed

    Bilal, Muhammad; Asgher, Muhammad

    2015-12-10

    In view of compliance with increasingly stringent environmental legislation, an eco-friendly treatment technology of industrial dyes and effluents is a major environmental challenge in the color industry. In present study, a promising and eco-friendly entrapment approach was adopted to immobilize purified manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum IBL-05 on Ca-alginate beads. The immobilized MnP was subsequently used for enhanced decolorization and detoxification of textile reactive dyes). MnP isolated from solid-state culture of G. lucidum IBL-05, presented highest immobilization yield (83.9 %) using alginate beads prepared at optimized conditions of 4 % (w/v) sodium alginate, 2 % (w/v) Calcium chloride (CaCl2) and 0.5 mg/ml enzyme concentration. Immobilization of MnP enhanced optimum temperature but caused acidic shift in optimum pH of the enzyme. The immobilized MnP showed optimum activity at pH 4.0 and 60 °C as compared to pH 5.0 and 35 °C for free enzyme. The kinetic parameters K(m) and V(max) of MnP were significantly improved by immobilization. The enhanced catalytic potential of immobilized MnP led to 87.5 %, 82.1 %, 89.4 %, 95.7 % and 83 % decolorization of Sandal-fix Red C4BLN, Sandal-fix Turq Blue GWF, Sandal-fix Foron Blue E2BLN, Sandal-fix Black CKF and Sandal-fix Golden Yellow CRL dyes, respectively. The insolubilized MnP was reusable for 7 repeated cycles in dye color removal. Furthermore, immobilized MnP also caused a significant reduction in biochemical oxygen demand (BOD) (94.61-95.47 %), chemical oxygen demand (COD) (91.18-94.85 %), and total organic carbon (TOC) (89.58-95 %) of aqueous dye solutions. G. lucidum MnP was immobilized in Ca-alginate beads by entrapment method to improve its practical effectiveness. Ca-alginate bound MnP was catalytically more vigorous, thermo-stable, reusable and worked over wider ranges of pH and temperature as compared to its free counterpart. Results of cytotoxicity like hemolytic and brine shrimp lethality tests suggested that Ca-alginate immobilized MnP may effectively be used for detoxification of dyes and industrial effluents.

  17. Structural Basis for the Regulation of Muscle Contraction by Troponin and Tropomyosin

    PubMed Central

    Galińska-Rakoczy, Agnieszka; Engel, Patti; Xu, Chen; Jung, HyunSuk; Craig, Roger; Tobacman, Larry S.; Lehman, William

    2008-01-01

    The molecular switching mechanism governing skeletal and cardiac muscle contraction couples the binding of Ca2+ on troponin to the movement of tropomyosin on actin filaments. Despite years of investigation, this mechanism remains unclear because it has not yet been possible to directly assess the structural influence of troponin on tropomyosin that causes actin filaments, and hence myosin-crossbridge cycling and contraction, to switch on and off. A C-terminal domain of troponin I is thought to be intimately involved in inducing tropomyosin movement to an inhibitory position that blocks myosin-crossbridge interaction. Release of this regulatory, latching domain from actin after Ca2+-binding to TnC presumably allows tropomyosin movement away from the inhibitory position on actin, thus initiating contraction. However, the structural interactions of the regulatory domain of TnI with tropomyosin and actin that cause tropomyosin movement are unknown and thus the regulatory process is not well defined. Here, thin filaments were labeled with an engineered construct representing C-terminal TnI and then 3D-EM was used to resolve where troponin is anchored on actin-tropomyosin. EM-reconstruction showed how TnI-binding to both actin and tropomyosin at low-Ca2+ competes with tropomyosin for a common site on actin and drives tropomyosin movement to a constrained, relaxing position to inhibit myosin-crossbridge association. Thus the observations reported reveal the structural mechanism responsible for troponin-tropomyosin-mediated steric-interference of actin-myosin interaction that regulates muscle contraction. PMID:18514658

  18. Effect of angiotensin II-induced arterial hypertension on the voltage-dependent contractions of mouse arteries.

    PubMed

    Fransen, Paul; Van Hove, Cor E; Leloup, Arthur J A; Schrijvers, Dorien M; De Meyer, Guido R Y; De Keulenaer, Gilles W

    2016-02-01

    Arterial hypertension (AHT) affects the voltage dependency of L-type Ca(2+) channels in cardiomyocytes. We analyzed the effect of angiotensin II (AngII)-induced AHT on L-type Ca(2+) channel-mediated isometric contractions in conduit arteries. AHT was induced in C57Bl6 mice with AngII-filled osmotic mini-pumps (4 weeks). Normotensive mice treated with saline-filled osmotic mini-pumps were used for comparison. Voltage-dependent contractions mediated by L-type Ca(2+) channels were studied in vaso-reactive studies in vitro in isolated aortic and femoral arteries by using extracellular K(+) concentration-response (KDR) experiments. In aortic segments, AngII-induced AHT significantly sensitized isometric contractions induced by elevated extracellular K(+) and depolarization. This sensitization was partly prevented by normalizing blood pressure with hydralazine, suggesting that it was caused by AHT rather than by direct AngII effects on aortic smooth muscle cells. The EC50 for extracellular K(+) obtained in vitro correlated significantly with the rise in arterial blood pressure induced by AngII in vivo. The AHT-induced sensitization persisted when aortic segments were exposed to levcromakalim or to inhibitors of basal nitric oxide release. Consistent with these observations, AngII-treatment also sensitized the vaso-relaxing effects of the L-type Ca(2+) channel blocker diltiazem during K(+)-induced contractions. Unlike aorta, AngII-treatment desensitized the isometric contractions to depolarization in femoral arteries pointing to vascular bed specific responses of arteries to hypertension. AHT affects the voltage-dependent L-type Ca(2+) channel-mediated contraction of conduit arteries. This effect may contribute to the decreased vascular compliance in AHT and explain the efficacy of Ca(2+) channel blockers to reduce vascular stiffness and central blood pressure in AHT.

  19. Heat inactivation of a norovirus surrogate in cell culture lysate, abalone meat, and abalone viscera.

    PubMed

    Park, Shin Young; Bae, San-Cheong; Ha, Sang-Do

    2015-03-01

    The current study examined the effects of temperature and heat treatment duration on murine norovirus-1 (MNV-1) from both viral cell culture lysate (7-8 log10 PFU) and experimentally contaminated abalone meat and viscera (5-6 log10 PFU) as a model of human norovirus (NoV). MNV-1 titers in cell culture lysate, abalone meat, and abalone viscera were gradually reduced to 1.93-4.55, 1.79-3.00, and 2.26-3.26 log10 PFU/ml, respectively, after treatment at 70 °C for 1-10 min. Treatment at 85 °C for 1-5 min gradually reduced MNV-1 titers in abalone meat to 2.71-4.15 log10 PFU/ml. MNV-1 titers in abalone viscera were gradually reduced to 2.91-3.46 log10 PFU/ml after treatment at 85 °C for 1-3 min. No significant difference (P > 0.05) was found in MNV-1 titers in the abalone meat and viscera among treatment groups (70 °C for 5 min, 70 °C for 3 min, and 85 °C for 1 min). Complete inactivation of MNV-1 in cell culture lysate was determined at 85 °C for ≥1 min and 100 °C for ≥0.5 min. Complete inactivation of MNV-1 in abalone was determined at 100 °C for ≥0.5 min for meat, and 85 °C for 5 min and 100 °C for ≥0.5 min for viscera. At treatments at 70 °C, the Td-values (3 log reduction time) were significantly lower (P < 0.05) in the cell culture lysate (3.38) than for the abalone meat (6.07) and viscera (10.73). Td = 3 values were not significantly different (P > 0.05) between abalone meat (1.78) and abalone viscera (1.33) at treatments at 85 °C. This study suggests that 100 °C for ≥0.5 min could potentially be used to inactivate NoV in molluscan shellfishes, including viscera.

  20. Fabrication and Characterization of (100),(001)-Oriented Reduction-Resistant Lead-Free Piezoelectric (Ba,Ca)TiO3 Ceramics Using Platelike Seed Crystals

    NASA Astrophysics Data System (ADS)

    Ichikawa, Hiroki; Sakamoto, Wataru; Akiyama, Yoshikazu; Maiwa, Hiroshi; Moriya, Makoto; Yogo, Toshinobu

    2013-09-01

    The preparation of reduction-resistant (Ba,Ca)TiO3 ceramics as lead-free piezoelectric materials was studied. To improve their electrical properties, (100),(001)-oriented (Ba0.85Ca0.15)TiO3 ceramics were fabricated by the reactive templated grain growth method using a mixture of platelike CaTiO3 and BaTiO3 particles. The platelike CaTiO3 and BaTiO3 particles were prepared through a topochemical microcrystal conversion process using CaBi4Ti4O15 and BaBi4Ti4O15 plate-like precursor crystals. The 100 orientation degree of the grain-oriented (Ba0.85Ca0.15)TiO3 ceramics was 92%, as estimated by Lotgering's equation. In addition, 1 mol % Ba excess and 1 mol % Mn-doped (Ba0.85Ca0.15)TiO3 sintered bodies, which were sintered at 1350 °C in an Ar flow containing H2 (0.3%), had sufficient resistivity to allow the characterization of electrical properties. The ferroelectric and field-induced strain properties of the (Ba0.85Ca0.15)TiO3 ceramics, sintered in the reducing atmosphere, were markedly improved as a result of fabricating grain-oriented samples. The field-induced strain coefficient (estimated from the slope of the unipolar strain loop) of the nonreducible (100),(001)-oriented (Ba0.85Ca0.15)TiO3 ceramics reached 570 pm/V, which was higher than that of polycrystals (260 pm/V) with no preferential orientation.

  1. Chloroplast DNA codon use: evidence for selection at the psb A locus based on tRNA availability.

    PubMed

    Morton, B R

    1993-09-01

    Codon use in the three sequenced chloroplast genomes (Marchantia, Oryza, and Nicotiana) is examined. The chloroplast has a bias in that codons NNA and NNT are favored over synonymous NNC and NNG codons. This appears to be a consequence of an overall high A + T content of the genome. This pattern of codon use is not followed by the psb A gene of all three genomes and other psb A sequences examined. In this gene, the codon use favors NNC over NNT for twofold degenerate amino acids. In each case the only tRNA coded by the genome is complementary to the NNC codon. This codon use is similar to the codon use by chloroplast genes examined from Chlamydomonas reinhardtii. Since psb A is the major translation product of the chloroplast, this suggests that selection is acting on the codon use of this gene to adapt codons to tRNA availability, as previously suggested for unicellular organisms.

  2. Contraction Twinning Dominated Tensile Deformation and Subsequent Fracture in Extruded Mg-1Mn (Wt Pct) at Ambient Temperature

    NASA Astrophysics Data System (ADS)

    Chakkedath, A.; Maiti, T.; Bohlen, J.; Yi, S.; Letzig, D.; Eisenlohr, P.; Boehlert, C. J.

    2018-06-01

    Due to their excellent strength-to-weight ratio, Mg alloys are attractive for applications where weight savings are critical. However, the limited cold formability of wrought Mg alloys severely restricts their widespread usage. In order to study the role that deformation twinning might play in limiting the elongation-to-failure ({ɛ} _{ {f}}), in-situ tensile tests along the extrusion axis of Mg-1Mn (wt pct) were performed at 323 K, 423 K, and 523 K. The alloy exhibited a strong basal texture such that most of the grains experienced compression along their < {c}> -axis during deformation. At 323 K, fracture occurred at about 10 pct strain. Although basal, prismatic, and pyramidal < {c+a}> slip activity was observed along with extension twinning, contraction twinning significantly influenced the deformation, and such twins evolved into {10{\\bar{1}}1}-{10{\\bar{1}}2} double twins. Crystal plasticity simulation showed localized shear deformation within the contraction twins and double twins due to the enhanced activity of basal slip in the reoriented twin volume. Due to this, the twin-matrix interface was identified to be a potential crack initiation site. Thus, contraction twins were considered to have led to the failure of the material at a relatively low strain, suggesting that this deformation mode is detrimental to the cold formability of Mg and its alloys. With increasing temperature, there was a significant decrease in the activity of contraction twinning as well as extension twinning, along with a decrease in the tensile strength and an increase in the {ɛ} _{ {f}} value. A combination of basal, prismatic, and pyramidal < {c+a}> slips accounted for a large percentage of the observed deformation activity at 423 K and 523 K. The lack of contraction twinning was explained by the expected decrease in the critical resolved shear stress values for pyramidal < {c+a}> slip, and the improved {ɛ} _{ {f}} values at elevated temperatures were attributed to the vanishing activity of contraction twinning.

  3. Contraction Twinning Dominated Tensile Deformation and Subsequent Fracture in Extruded Mg-1Mn (Wt Pct) at Ambient Temperature

    NASA Astrophysics Data System (ADS)

    Chakkedath, A.; Maiti, T.; Bohlen, J.; Yi, S.; Letzig, D.; Eisenlohr, P.; Boehlert, C. J.

    2018-03-01

    Due to their excellent strength-to-weight ratio, Mg alloys are attractive for applications where weight savings are critical. However, the limited cold formability of wrought Mg alloys severely restricts their widespread usage. In order to study the role that deformation twinning might play in limiting the elongation-to-failure ({ɛ} f ), in-situ tensile tests along the extrusion axis of Mg-1Mn (wt pct) were performed at 323 K, 423 K, and 523 K. The alloy exhibited a strong basal texture such that most of the grains experienced compression along their < {c}> -axis during deformation. At 323 K, fracture occurred at about 10 pct strain. Although basal, prismatic, and pyramidal < {c+a}> slip activity was observed along with extension twinning, contraction twinning significantly influenced the deformation, and such twins evolved into {10{\\bar{1}} 1}-{10{\\bar{1}} 2} double twins. Crystal plasticity simulation showed localized shear deformation within the contraction twins and double twins due to the enhanced activity of basal slip in the reoriented twin volume. Due to this, the twin-matrix interface was identified to be a potential crack initiation site. Thus, contraction twins were considered to have led to the failure of the material at a relatively low strain, suggesting that this deformation mode is detrimental to the cold formability of Mg and its alloys. With increasing temperature, there was a significant decrease in the activity of contraction twinning as well as extension twinning, along with a decrease in the tensile strength and an increase in the {ɛ} f value. A combination of basal, prismatic, and pyramidal < {c+a}> slips accounted for a large percentage of the observed deformation activity at 423 K and 523 K. The lack of contraction twinning was explained by the expected decrease in the critical resolved shear stress values for pyramidal < {c+a}> slip, and the improved {ɛ} f values at elevated temperatures were attributed to the vanishing activity of contraction twinning.

  4. Dollar Summary of Prime Contract Awards by State, Place and Contractor, FY 85. Part 1 (Alexandria, Alabama - Yorkville, Illinois.

    DTIC Science & Technology

    1985-01-01

    m - zago zi 9zs 0 m U)l 4c140 0 "< z( . 40 21 I z)-0 "o 0 W 0 >W~ zl "I 00 (04It06 lN t04 01 U (i C0...IU I. In 4c * NO a 05 ’ 44 E - I I A 0 CO I q~o c N M inI5V F z I. I. . .- 01 I- 0. 0 -1Nc4 .4 CL C N- (ogo - C- z I.- w R a. A0 w . z 0 0-I" 14.$A I9...a.n GoCV)t-0 a C1 m n m ’ I. CVI CV in OD) N C) 4 0 ~ ~~ a . r a O aca 40 Z au ’ FJ.. *.4hmN 0- I : N 1 04 1 I. *c’ a-J a 00C)r P oI 4 a . 9 -4 .a a

  5. Role of extracellular and intracellular sources of Ca2+ in sarafotoxin S6b-induced contraction of strips of the rat aorta.

    PubMed Central

    Watanabe, C.; Hirano, K.; Kanaide, H.

    1993-01-01

    1. The effect of sarafotoxin S6b (sarafotoxin), a vasoconstrictor peptide, on cytosolic Ca2+ concentration ([Ca2+]i) and force in rat aortic strips loaded with fura-2 was determined by front-surface fluorometry. The objective was to elucidate the role of extracellular and intracellular Ca2+ in the mechanism of action of this peptide. 2. In the presence of extracellular 1.25 mM Ca2+, sarafotoxin induced a biphasic response consisting of an initial rapid increase in [Ca2+]i followed by a secondary sustained increase. Tension developed slowly but was sustained during the application of sarafotoxin. Diltiazem (10 nM-0.1 mM) partially inhibited both the increases in [Ca2+]i and tension. 3. In the presence of extracellular Ca2+, the force developed in relation to the increase in [Ca2+]i ([Ca2+]i-force relationship) observed with sarafotoxin was much greater than that observed upon K+ depolarization. In the presence of diltiazem the sarafotoxin-induced [Ca2+]i-force relationship was shifted even further to the left. 4. In the absence of extracellular Ca2+, sarafotoxin induced a transient increase in [Ca2+]i and a sustained contraction. Extending the incubation time in Ca(2+)-free physiological solution, resulted in smaller responses. However, after 60 min in Ca(2+)-free solution, sarafotoxin induced a sustained contraction but no change in [Ca2+]i. This residual contraction was inhibited by H-7, which is known to inhibit protein kinase C. 5. After treatment with caffeine to reduce intracellular stored Ca2+, sarafotoxin could still elicit increases in [Ca2+]i and in tension, showing that the caffeine-sensitive intracellular Ca2+ store partially overlaps with the sarafotoxin-sensitive store.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8428211

  6. A new series of oxycarbonate superconductors (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takayama-Muromachi, E.; Kawashima, T.; Matsui, Y.

    1994-12-31

    We found a new series of oxycarbonate superconductors in the Ba-Ca-Cu-C-O system under high pressure of 5 GPa. Their ideal formula is (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1 ((Cu,C)-m(m+1)(n-1)n). Thus far, n=3, 4 members of the m=1 series, (Cu,C)-1223 and (Cu,C)-1234, have been prepared in bulk while n=4, 5 members, (Cu,C)-2334 and (Cu,C)-2345, have been prepared for the m=2 series. (Cu,C)-1223 shows superconductivity below 67 K while T{sub c}`s of other compounds are above 110 K. In particular, (Cu,C)=1234 has the highest T{sub c} of 117 K.

  7. 13. 'Transverse Bracing for 1 208'101/2' C. to C. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. 'Transverse Bracing for 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing of Sacramento River, So. Pac. Co., The Phoenix Bridge Co., C.O. 836D, Drawing No. 7, Scale - 1' = 1', Engineer - B.M. Krohn, May 11th `01, Slaughter' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  8. Enhancement of Palmarumycins C(12) and C(13) production in liquid culture of endophytic fungus Berkleasmium sp. Dzf12 after treatments with metal ions.

    PubMed

    Mou, Yan; Luo, Haiyu; Mao, Ziling; Shan, Tijiang; Sun, Weibo; Zhou, Kaiyi; Zhou, Ligang

    2013-01-07

    The influences of eight metal ions (i.e., Na+, Ca2+, Ag+, Co2+, Cu2+, Al3+, Zn2+, and Mn4+) on mycelia growth and palmarumycins C(12) and C(13) production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12 were investigated. Three metal ions, Ca2+, Cu2+ and Al3+ were exhibited as the most effective to enhance mycelia growth and palmarumycin production. When calcium ion (Ca2+) was applied to the medium at 10.0 mmol/L on day 3, copper ion (Cu2+) to the medium at 1.0 mmol/L on day 3, aluminum ion (Al3+) to the medium at 2.0 mmol/L on day 6, the maximal yields of palmarumycins C(12) plus C(13) were obtained as 137.57 mg/L, 146.28 mg/L and 156.77 mg/L, which were 3.94-fold, 4.19-fold and 4.49-fold in comparison with that (34.91 mg/L) of the control, respectively. Al3+ favored palmarumycin C(12) production when its concentration was higher than 4 mmol/L. Ca2+ had an improving effect on mycelia growth of Berkleasmium sp. Dzf12. The combination effects of Ca2+, Cu2+ and Al3+ on palmarumycin C(13) production were further studied by employing a statistical method based on the central composite design (CCD) and response surface methodology (RSM). By solving the quadratic regression equation between palmarumycin C(13) and three metal ions, the optimal concentrations of Ca2+, Cu2+ and Al3+ in medium for palmarumycin C(13) production were determined as 7.58, 1.36 and 2.05 mmol/L, respectively. Under the optimum conditions, the predicted maximum palmarumycin C(13) yield reached 208.49 mg/L. By optimizing the combination of Ca2+, Cu2+ and Al3+ in medium, palmarumycin C(13) yield was increased to 203.85 mg/L, which was 6.00-fold in comparison with that (33.98 mg/L) in the original basal medium. The results indicate that appropriate metal ions (i.e., Ca2+, Cu2+ and Al3+) could enhance palmarumycin production. Application of the metal ions should be an effective strategy for palmarumycin production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12.

  9. Influences of Ru-doping on the magnetic properties of Ca0.85Pr0.15Mn1- x Ru x O3

    NASA Astrophysics Data System (ADS)

    Phan, T. L.; Zhang, Y. D.; Yu, S. C.; Thanh, P. Q.; Yen, P. D. H.

    2012-11-01

    CaMnO3 is an antiferromagnet, in which the super-exchange interaction taking place between Mn4+ ions plays an important role. The doping of a small amount of 15% Pr into the Ca site, Ca0.85Pr0.15MnO3, leads to the appearance of Mn3+ ions, and introduces the ferromagnetic (FM) double-exchange interaction between Mn3+ and Mn4+ ions, which is dominant in a narrow temperature range of 90 ˜ 115 K. The FM interaction becomes strong for Ca0.85Pr0.15MnO3 doped with 4 and 8% Ru into the Mn site ( i.e., Ca0.85Pr0.15Mn1- x Ru x O3 with x = 0.04 and 0.08). The Curie temperature obtained for x = 0.04 and 0.08 are about 135 and 180 K, respectively. While the FM interaction in the former is dominant due to Mn3+-Mn4+ exchange pairs, the latter has the contribution of Ru ions. This results in remarkable differences in the features of their FM-paramagnetic phase transitions and their coercive fields H c .

  10. Influence of nickel doping on oxygen-ionic conductivity of the n = 1 Ruddlesden-Popper Phases La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4−δ} (δ = 0.0905)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Midouni, Adnene; Université de Tunis El Manar, Campus Universitaire Farhat Hached, B.P. No 94- Rommana, 1068 Tunis; Houchati, Mohamed Ikbal, E-mail: ikb_med@yahoo.fr

    2016-08-15

    The results of the synthesis and characterization of the optimally doped La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4-δ} solid solution with x = 0, 0.1, 0.2 and 0.3 are reported. The versatility of these La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4−δ} materials is explained on the basis of structural features and the ability to accommodate oxygen nonstoichiometry. According to powder X-ray and neutron diffraction data, La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4−δ} adopts the tetragonal structure with oxygen vacancies occurring preferentially at the O{sub ap} sites within the {(La/Ca)O} layers of the perovskite blocks and the oxygen deviation from stoichiometry δ was foundmore » to be δ=0.0905(6). The bulk conductivity indicated an Arrhenius-type thermally activated process and oxygen vacancies are the possible ionic charge carriers at T=270 °C. An increase of the conductivity was detected when Ni was introduced. With nickel ratio variation, a strong correlation was observed between the Cu(Ni)-O{sub ap} apical bond length variation and the conductivity variation through controlling the O{sup 2−} ion migration. - Highlights: • We report the synthesis and structure of the La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4−δ} (0≤x≤0.3; δ=0.0905) compounds. • La{sub 1.85}Ca{sub 0.15}(Cu{sub 1−x}Ni{sub x})O{sub 4−δ} (x=0.0, 0.2, 0.3) doped with Ni{sup 2+} have a higher conductivity than undoped La{sub 1.85}Ca{sub 0.15}CuO{sub 4−δ}. • At T=270 °C, sample x=0.3 has the highest conductivity (0.2915 sm{sup −1}).« less

  11. 12. 'Portal Strut for 1 208'101/2' C. to C. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. 'Portal Strut for 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing of Sacramento River, So. Pac. Co., The Phoenix Bridge Co., C.O. 836D, Drawing No. 12, Scale - 1' = 1', Engineer - B.M. Krohn, May 22nd `01, J.C.S.' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  12. Fatigability and Recovery of Arm Muscles with Advanced Age for Dynamic and Isometric Contractions

    PubMed Central

    Yoon, Tejin; Schlinder-Delap, Bonnie; Hunter, Sandra K.

    2012-01-01

    This study determined whether age-related mechanisms can increase fatigue of arm muscles during maximal velocity dynamic contractions, as occurs in the lower limb. We compared elbow flexor fatigue of young (n=10, 20.8 ± 2.7 years) and old men (n=16, 73.8 ± 6.1 years) during and in recovery from a dynamic and an isometric postural fatiguing task. Each task was maintained until failure while supporting a load equivalent to 20% of maximal voluntary isometric contraction (MVIC) torque. Transcranial magnetic stimulation (TMS) was used to assess supraspinal fatigue (superimposed twitch, SIT) and muscle relaxation. Time to failure was longer for old men than young for the isometric task (9.5±3.1 vs. 17.2±7.0 min, P=0.01) but similar for the dynamic task (6.3±2.4 min vs. 6.0±2.0 min, P = 0.73). Initial peak rate of relaxation was slower for the old men than young, and associated with a longer time to failure for both tasks (P<0.05). Low initial power during elbow flexion was associated with the greatest difference (reduction) in time to failure between the isometric task and dynamic task (r =−0.54, P=0.015). SIT declined after both fatigue tasks similarly with age, although recovery of SIT was associated with MVIC recovery for the old (both sessions) but not the young. Biceps brachii and brachioradialis EMG activity (%MVIC) of old men were greater than young during the dynamic fatiguing task (P<0.05), but similar during the isometric task. Muscular mechanisms and greater relative muscle activity (EMG activity) explain the greater fatigue during dynamic task for the old men compared with young in elbow flexor muscles. Recovery of MVC torque however relies more on recovery of supraspinal fatigue among older men than the young men. PMID:23103238

  13. Effect of tenderizers combined with organic acids on Escherichia coli O157:H7 thermal resistance in non-intact beef.

    PubMed

    Yoon, Yohan; Mukherjee, Avik; Belk, Keith E; Scanga, John A; Smith, Gary C; Sofos, John N

    2009-07-31

    Non-intact beef products include beef cuts that have been ground, mechanically tenderized, restructured, or have been injected with solutions to enhance tenderness and/or flavor. This study examined the effects of tenderizing salts and organic acids on thermal inactivation of Escherichia coli O157:H7 in a ground beef model system simulating non-intact beef products. Ground beef (95% lean; 700 g batches) was mixed (2 min) with nothing (C) or solutions (22 ml) of water (WA), calcium ascorbate (CaA, 0.86%; wt/wt), calcium chloride (CaC, 0.23%; wt/wt), acetic acid (AA, 0.3%; v/wt), citric acid (CA, 0.2%; wt/wt), NaCl (NA, 0.5%; wt/wt), and mixtures of CaA/NA, CaC/NA, AA/NA, CA/NA, CaA/CaC/NA, CaA/AA/NA, CaA/CA/NA, CaC/AA/NA and CaC/CA/NA. Samples (30 g) were extruded into test tubes, inoculated (7 log CFU/g) with E. coli O157:H7 (5-strain mixture), and stored (4 degrees C) overnight. Samples were then cooked to 60 degrees C or 65 degrees C, in a water bath, to simulate rare or medium-rare doneness of beef, respectively. Weight, fat and moisture losses, total bacterial (tryptic soy agar) and E. coli O157:H7 (modified eosin methylene blue agar, and modified sorbitol MacConkey agar) populations were determined after inoculation, storage, and cooking. Fat and moisture losses were not affected by treatment and temperature, while weight losses increased at 65 degrees C and in acid treated samples (60 degrees C). E. coli O157:H7 survivors were generally lower (P<0.05) in acid treated than non-acid treated samples. Pathogen counts in samples treated with tenderizers (CaA, CaC) and NA were not different (P> or =0.05) than those of control samples. Thus, inclusion of organic acids in beef tenderizing recipes may help in thermal inactivation of E. coli O157:H7 that may been transferred to the interior of non-intact products during their production.

  14. Comparative Dielectric and Ferroelectric Characteristics of Bi0.5Na0.5TiO3, CaCu3Ti4O12, and 0.5Bi0.5Na0.5TiO3-0.5CaCu3Ti4O12 Electroceramics

    NASA Astrophysics Data System (ADS)

    Singh, Laxman; Yadava, Shiva Sundar; Sin, Byung Cheol; Rai, Uma Shanker; Mandal, K. D.; Lee, Youngil

    2016-06-01

    The dielectric and ferroelectric characteristics of Bi0.5Na0.5TiO3 (BNT), CaCu3Ti4O12 (CCTO), and 0.5Bi0.5Na0.5TiO3-0.5CaCu3Ti4O12 (BNT/CCTO) ceramics are compared. X-ray diffraction patterns confirmed the formation of single phase of all the ceramics after sintering at 950°C for 15 h. Scanning electron microscopy images of the sintered ceramics reveal average grain sizes in the range from 200 nm to 2.5 μm. Energy-dispersive x-ray mapping and x-ray photoelectron spectroscopy show the presence of the elements Bi, Na, Ca, Cu, Ti, and O with uniform distribution in the ceramics. BNT/CCTO exhibits high dielectric constant ( ɛ r ˜ 6.9 × 104) compared with BNT ( ɛ r ˜ 0.13 × 104) and CCTO ( ɛ r ˜ 1.68 × 104) ceramics at 1 kHz and 503 K. The high dielectric constant of BNT/CCTO compared with BNT and CCTO is associated with a major contribution from grain boundaries, as confirmed by impedance and modulus analyses. The P- E hysteresis loop of all the ceramics measured at room temperature and 50°C exhibited typical ferroelectric nature. The remanent polarization ( P r) of BNT (1.58 μC/cm2) and CCTO (0.654 μC/cm2) ceramics are higher than that of BNT/CCTO (0.267 μC/cm2) ceramic.

  15. Effects of rapid shortening on rate of force regeneration and myoplasmic [Ca2+] in intact frog skeletal muscle fibres

    PubMed Central

    Vandenboom, R; Claflin, D R; Julian, F J

    1998-01-01

    The effect of rapid shortening on rate of force regeneration (dF/dtR) was examined in single, intact frog (Rana temporaria) skeletal muscle fibres (3·0 °C). Step releases leading to unloaded shortening were applied after 500 ms of stimulation, during the plateau of an isometric tetanus. Initial mean sarcomere length ranged from 2·05 to 2·35 μm; force regeneration after shortening was at 2·00 μm.Values for dF/dtR following a 25 nm half-sarcomere−1 release were 3·17 ± 0·17 (mean ± s.e.m., n= 8) times greater than the initial rate of rise of force before release (dF/dtI). As release size was increased from 25 to 175 nm half-sarcomere−1, the relationship between release size and dF/dtR decreased sharply before attaining a plateau value that was 1·34 ± 0·09 times greater than dF/dtI. Despite wide variations in dF/dtR, the velocity of unloaded shortening remained constant (2·92 ± 0·08 μm half-sarcomere−1 s−1; n= 8) for the different release amplitudes used in this study.To investigate its role in the attenuation of dF/dtR with increased shortening, the effects of rapid ramp (constant velocity) shortening on intracellular free Ca2+ concentration ([Ca2+]i) were monitored using the Ca2+-sensitive fluorescent dye furaptra. Compared with an isometric contraction, rapid fibre shortening was associated with a transient increase in [Ca2+]i while force regeneration after shortening was associated with a transient reduction in [Ca2+]i. The greatest reductions in [Ca2+]i were associated with the largest amplitude ramps.Cross-bridge-mediated modifications of the Ca2+ affinity of troponin C (TnC) may explain the fluctuations in [Ca2+]i observed during and after ramps. Associated fluctuations in TnC Ca2+ occupancy could play a role in the reduction of dF/dtR with increasing release size. PMID:9679172

  16. Computational Insights into the Interactions between Calmodulin and the c/nSH2 Domains of p85α Regulatory Subunit of PI3Kα: Implication for PI3Kα Activation by Calmodulin.

    PubMed

    Ni, Duan; Liu, Dingyu; Zhang, Jian; Lu, Shaoyong

    2018-01-04

    Calmodulin (CaM) and phosphatidylinositide-3 kinase (PI3Kα) are well known for their multiple roles in a series of intracellular signaling pathways and in the progression of several human cancers. Crosstalk between CaM and PI3Kα has been an area of intensive research. Recent experiments have shown that in adenocarcinoma, K-Ras4B is involved in the CaM-PI3Kα crosstalk. Based on experimental results, we have recently put forward a hypothesis that the coordination of CaM and PI3Kα with K-Ras4B forms a CaM-PI3Kα-K-Ras4B ternary complex, which leads to the formation of pancreatic ductal adenocarcinoma. However, the mechanism for the CaM-PI3Kα crosstalk is unresolved. Based on molecular modeling and molecular dynamics simulations, here we explored the potential interactions between CaM and the c/nSH2 domains of p85α subunit of PI3Kα. We demonstrated that CaM can interact with the c/nSH2 domains and the interaction details were unraveled. Moreover, the possible modes for the CaM-cSH2 and CaM-nSH2 interactions were uncovered and we used them to construct a complete CaM-PI3Kα complex model. The structural model of CaM-PI3Kα interaction not only offers a support for our previous ternary complex hypothesis, but also is useful for drug design targeted at CaM-PI3Kα protein-protein interactions.

  17. Effect of Clausena excavata Burm. f. (Rutaceae) leaf extract on wound healing and antioxidant activity in rats.

    PubMed

    Albaayit, Shaymaa Fadhel Abbas; Abba, Yusuf; Rasedee, Abdullah; Abdullah, Noorlidah

    2015-01-01

    Clausena excavata is a well-known plant used in folkloric medicine for the treatment of different ailments. This study aimed to determine the in vitro cytoxicity of its leaf solvent extracts as well as the in vivo wound healing and antioxidant activities of the methanolic extracts of C. excavata (MECE). HaCaT (keratocyte) and Vero cell lines were used for evaluation of the in vitro cytotoxic effects, while the in vivo wound healing and antioxidant activities were determined in skin wounds inflicted on rats. Twenty adult male Sprague-Dawley rats were divided into five groups of four animals each. Approximately 3.14 cm(2) excisional wound was inflicted on the nape of each rat following anesthesia. The treatment groups received topical application of MECE at 50 mg/mL (MECE-LD [low dose]), 100 mg/mL (MECE-MD [medium dose]), and 200 mg/mL (MECE-HD [high dose]), while the negative control group was treated with gum acacia in normal saline and the positive control group with intrasite gel. Wound contraction was evaluated on days 5, 10, and 15 after wound infliction, and tissue from wound area was collected at day 15 post-wound infliction for antioxidant enzyme evaluation and histopathological analyses. Generally, Vero cells were more resistant to the cytotoxic effects of the solvent extracts as compared with HaCaT cells. Chloroform (CH) and ethyl acetate (EA) extracts of C. excavata were toxic to HaCaT cells at 200 and 400 µg/mL, but the same concentrations showed higher (P<0.05) viability in Vero cells. There was significantly (P<0.01) greater wound contraction at days 10 and 15 post-wound infliction in all the treatment groups than in the control groups. Histopathologically, the MECE-HD-treated wound showed significantly (P<0.05) lesser inflammatory cell proliferation, degeneration, and distribution of granulation tissue than other groups. Similarly, the degree of collagen maturation, angiogenesis, and collagen distribution were significantly (P<0.05) lower in MECE-HD than in other groups. The MECE-HD, MECE-MD, and intrasite treatment groups showed a significantly (P<0.05) higher number of VEGF-positive and TGF-β1-positive cells in the skin wound than the control groups. The activities of superoxide dismutase and catalase were significantly (P<0.01) higher in the MECE-HD and intrasite treatment groups than in the other groups. Lipid peroxidase activity of the treated groups was significantly (P<0.01) lower than that in the control group. The study showed that MECE is a potent wound healing agent through anti-inflammatory and antioxidant effects that enhanced the rate of wound contraction, re-epithelialization, and collagen deposition. The effect of MECE is suggested to be due to its high polyphenolic compound content.

  18. Effect of Clausena excavata Burm. f. (Rutaceae) leaf extract on wound healing and antioxidant activity in rats

    PubMed Central

    Albaayit, Shaymaa Fadhel Abbas; Abba, Yusuf; Rasedee, Abdullah; Abdullah, Noorlidah

    2015-01-01

    Clausena excavata is a well-known plant used in folkloric medicine for the treatment of different ailments. This study aimed to determine the in vitro cytoxicity of its leaf solvent extracts as well as the in vivo wound healing and antioxidant activities of the methanolic extracts of C. excavata (MECE). HaCaT (keratocyte) and Vero cell lines were used for evaluation of the in vitro cytotoxic effects, while the in vivo wound healing and antioxidant activities were determined in skin wounds inflicted on rats. Twenty adult male Sprague-Dawley rats were divided into five groups of four animals each. Approximately 3.14 cm2 excisional wound was inflicted on the nape of each rat following anesthesia. The treatment groups received topical application of MECE at 50 mg/mL (MECE-LD [low dose]), 100 mg/mL (MECE-MD [medium dose]), and 200 mg/mL (MECE-HD [high dose]), while the negative control group was treated with gum acacia in normal saline and the positive control group with intrasite gel. Wound contraction was evaluated on days 5, 10, and 15 after wound infliction, and tissue from wound area was collected at day 15 post-wound infliction for antioxidant enzyme evaluation and histopathological analyses. Generally, Vero cells were more resistant to the cytotoxic effects of the solvent extracts as compared with HaCaT cells. Chloroform (CH) and ethyl acetate (EA) extracts of C. excavata were toxic to HaCaT cells at 200 and 400 µg/mL, but the same concentrations showed higher (P<0.05) viability in Vero cells. There was significantly (P<0.01) greater wound contraction at days 10 and 15 post-wound infliction in all the treatment groups than in the control groups. Histopathologically, the MECE-HD-treated wound showed significantly (P<0.05) lesser inflammatory cell proliferation, degeneration, and distribution of granulation tissue than other groups. Similarly, the degree of collagen maturation, angiogenesis, and collagen distribution were significantly (P<0.05) lower in MECE-HD than in other groups. The MECE-HD, MECE-MD, and intrasite treatment groups showed a significantly (P<0.05) higher number of VEGF-positive and TGF-β1-positive cells in the skin wound than the control groups. The activities of superoxide dismutase and catalase were significantly (P<0.01) higher in the MECE-HD and intrasite treatment groups than in the other groups. Lipid peroxidase activity of the treated groups was significantly (P<0.01) lower than that in the control group. The study showed that MECE is a potent wound healing agent through anti-inflammatory and antioxidant effects that enhanced the rate of wound contraction, re-epithelialization, and collagen deposition. The effect of MECE is suggested to be due to its high polyphenolic compound content. PMID:26203223

  19. Carnosic acid attenuates obesity-induced glucose intolerance and hepatic fat accumulation by modulating genes of lipid metabolism in C57BL/6J-ob/ob mice.

    PubMed

    Park, Mi-Young; Sung, Mi-Kyung

    2015-03-15

    Carnosic acid (CA), a major bioactive component of rosemary (Rosmarinus officinalis) leaves, is known to possess antioxidant and anti-adipogenic activities. In this study it was hypothesized that CA would ameliorate obesity-induced glucose intolerence and hepatic fat accumulation, and possible mechanisms are suggested. It was observed that a 0.02% (w/w) CA diet effectively decreased body weight, liver weight and blood triglyceride (TG) and total cholesterol levels (P < 0.05) compared with the control diet. CA at 0.02% significantly improved glucose tolerance, and hepatic TG accumulation was reduced in a dose-dependent manner. Hepatic lipogenic-related gene (L-FABP, SCD1 and FAS) expression decreased whereas lipolysis-related gene (CPT1) expression increased in animals fed the 0.02% CA diet (P < 0.05). Long-chain fatty acid content and the ratio of C18:1/C18:0 fatty acids were decreased in adipose tissue of animals fed the 0.02% CA diet (P < 0.05). Serum inflammatory mediators were also decreased significantly in animals fed the 0.02% CA diet compared with those of the obese control group (P < 0.05). These results suggest that CA is an effective anti-obesity agent that regulates fatty acid metabolism in C57BL/6J-ob/ob mice. © 2014 Society of Chemical Industry.

  20. 48 CFR 52.215-22 - Limitations on Pass-Through Charges-Identification of Subcontract Effort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... The offeror's proposal shall exclude excessive pass-through charges. (c) Performance of work by the..., under the contract, task order, or delivery order. (2) If the offeror intends to subcontract more than 70 percent of the total cost of work to be performed under the contract, task order, or delivery...

  1. An Investigation into the Nature of Non-Voiding Contractions Resulting from Detrusor Hyperreflexia in Neurogenic Bladders Following Spinal Cord Injury

    DTIC Science & Technology

    2015-06-01

    occasioned by numerous, rhythmic high pressure non-voiding contractions (NVC) during normal bladder filling. These NVC are responsible for incontinence...month experiment period) 2c. Final data analysis (data analysis will be ongoing throughout, this will represent the finalization of data period, 0.25...Sub-Tasks 2a and 2b. As of 9/2/14, we have completed much of the data analysis (Sub-Task 2c; see below for results). Analysis of abdominal

  2. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Munakata, M.; Huang, C.; Menkes, H.

    Activated protein kinase C and intracellular Ca/sup + +/ may act synergistically to produce physiological responses. It is possible to activate protein kinase C directly with phorbol esters and to increase intracellular Ca/sup + +/ by depolarizing cell membranes. Guinea pig tracheal rings were incubated at constant temperature in Krebs-Henseleit solution and isometric tension was recorded. Protein kinase C was activated with phorbol 12,13 - diacetate (PDA) and cell membranes were depolarized by lowering temperature, increasing external K/sup +/ concentration, or incubating with ouabain. At 37/sup 0/C, 1 /sup +/M PDA caused a fall in tension (0.67 +/- 0.06 g).more » This decrease in tension was equal to 43% of the near maximal contraction produced by 4 ..mu..M carbachol. At 22/sup 0/C 1 ..mu.. PDA caused an increase in tension (1.00 +/- 0.10 g). This increase in tension was equal to 61% of the contraction produced by 4 ..mu..M carbachol. When K/sup +/ was increased from the physiological concentration of 5.4 mM to 20 mM, 1 ..mu..M PDA caused an increase in tension of 1.11 +/- 0.15 g (56% of the 4 ..mu..M carbachol response). When 10 ..mu..M ouabain was added to the tissue bath, 1 ..mu..M PDA caused an increase in tension of 1.56 +/- 0.61 g (81% of the 4 ..mu..M carbachol response). Contractions produced by PDA at low temperature or high K were blocked by 1 ..mu..M verapamil or by 0.01 ..mu..M nifedipine. The authors conclude that the activation of protein kinase C causes contraction when cell membranes are depolarized and Ca/sup + +/ is allowed to enter the cells through voltage dependent channels.« less

  3. Myogenic tone is impaired at low arterial pressure in mice deficient in the low-voltage-activated CaV 3.1 T-type Ca(2+) channel.

    PubMed

    Björling, K; Morita, H; Olsen, M F; Prodan, A; Hansen, P B; Lory, P; Holstein-Rathlou, N-H; Jensen, L J

    2013-04-01

    Using mice deficient in the CaV 3.1 T-type Ca(2+) channel, the aim of the present study was to elucidate the molecular identity of non-L-type channels involved in vascular tone regulation in mesenteric arteries and arterioles. We used immunofluorescence microscopy to localize CaV 3.1 channels, patch clamp electrophysiology to test the effects of a putative T-type channel blocker NNC 55-0396 on whole-cell Ca(2+) currents, pressure myography and Ca(2+) imaging to test diameter and Ca(2+) responses of the applied vasoconstrictors, and Q-PCR to check mRNA expression levels of several Ca(2+) handling proteins in wild-type and CaV 3.1(-/-) mice. Our data indicated that CaV 3.1 channels are important for the maintenance of myogenic tone at low pressures (40-80 mm Hg), whereas they are not involved in high-voltage-activated Ca(2+) currents, Ca(2+) entry or vasoconstriction to high KCl in mesenteric arteries and arterioles. Furthermore, we show that NNC 55-0396 is not a specific T-type channel inhibitor, as it potently blocks L-type and non-L-type high-voltage-activated Ca(2+) currents in mouse mesenteric vascular smooth muscle cell. Our data using mice deficient in the CaV 3.1 T-type channel represent new evidence for the involvement of non-L-type channels in arteriolar tone regulation. We showed that CaV 3.1 channels are important for the myogenic tone at low arterial pressure, which is potentially relevant under resting conditions in vivo. Moreover, CaV 3.1 channels are not involved in Ca(2+) entry and vasoconstriction to large depolarization with, for example, high KCl. Finally, we caution against using NNC 55-0396 as a specific T-type channel blocker in native cells expressing high-voltage-activated Ca(2+) channels. Acta Physiologica © 2013 Scandinavian Physiological Society.

  4. Role of UGT1A1*6, UGT1A1*28 and ABCG2 c.421C>A polymorphisms in irinotecan-induced neutropenia in Asian cancer patients.

    PubMed

    Jada, Srinivasa Rao; Lim, Robert; Wong, Chiung Ing; Shu, Xiaochen; Lee, Soo Chin; Zhou, Qingyu; Goh, Boon Cher; Chowbay, Balram

    2007-09-01

    The objectives of the present study were (i) to study the pharmacogenetics of UGT1A1*6, UGT1A1*28 and ABCG2 c.421C>A in three distinct healthy Asian populations (Chinese, Malays and Indians), and (ii) to investigate the polygenic influence of these polymorphic variants in irinotecan-induced neutropenia in Asian cancer patients. Pharmacokinetic and pharmacogenetic analyses were done after administration of irinotecan as a 90-min intravenous infusion of 375 mg/m(2) once every 3 weeks (n = 45). Genotypic-phenotypic correlates showed a non-significant influence of UGT1A1*28 and ABCG2 c.421C>A polymorphisms on the pharmacokinetics of SN-38 (P > 0.05), as well as severity of neutropenia (P > 0.05). Significantly higher exposure levels to SN-38 (P = 0.018), lower relative extent of glucuronidation (REG; P = 0.006) and higher biliary index (BI; P = 0.003) were found in cancer patients homozygous for the UGT1A1*6 allele compared with patients harboring the reference genotype. The mean absolute neutrophil count (ANC) was 85% lower and the prevalence of grade 4 neutropenia (ANC < or = 500/microL) was 27% in patients homozygous for UGT1A1*6 compared with the reference group. Furthermore, the presence of the UGT1A1*6 allele was associated with an approximately 3-fold increased risk of developing severe grade 4 neutropenia compared with patients harboring the reference genotype. These exploratory findings suggest that homozygosity for UGT1A1*6 allele may be associated with altered SN-38 disposition and may increase the risk of severe neutropenia in Asian cancer patients, particularly in the Chinese cancer patients who comprised 80% (n = 36) of the patient population in the present study.

  5. TASAR Certification and Operational Approval Requirements - Analyses and Results

    NASA Technical Reports Server (NTRS)

    Koczo, Stefan, Jr.

    2015-01-01

    This report documents the results of research and development work performed by Rockwell Collins in addressing the Task 1 objectives under NASA Contract NNL12AA11C. Under this contract Rockwell Collins provided analytical support to the NASA Langley Research Center (LaRC) in NASA's development of a Traffic Aware Strategic Aircrew Requests (TASAR) flight deck Electronic Flight Bag (EFB) application for technology transition into operational use. The two primary objectives of this contract were for Rockwell Collins and the University of Iowa OPL to 1) perform an implementation assessment of TASAR toward early certification and operational approval of TASAR as an EFB application (Task 1 of this contract), and 2) design, develop and conduct two Human-in-the-Loop (HITL) simulation experiments that evaluate TASAR and the associated Traffic Aware Planner (TAP) software application to determine the situational awareness and workload impacts of TASAR in the flight deck, while also assessing the level of comprehension, usefulness, and usability of the features of TAP (Task 2 of this contract). This report represents the Task 1 summary report. The Task 2 summary report is provided in [0].

  6. 77 FR 8818 - Public Availability of Consumer Product Safety Commission FY 2011 Service Contract Inventory

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... through a contract or task order; (B) The organizational component of the executive agency administering the contract, and the organizational component of the agency whose requirements are being met through contractor performance of the service; (C) The total dollar amount obligated for services under the contract...

  7. Betaine attenuates memory impairment after water-immersion restraint stress and is regulated by the GABAergic neuronal system in the hippocampus.

    PubMed

    Kunisawa, Kazuo; Kido, Kiwamu; Nakashima, Natsuki; Matsukura, Takuya; Nabeshima, Toshitaka; Hiramatsu, Masayuki

    2017-02-05

    GABA mediated neuronal system regulates hippocampus-dependent memory and stress responses by controlling plasticity and neuronal excitability. Here, we demonstrate that betaine ameliorates water-immersion restraint stress (WIRS)-induced memory impairments. This improvement was inhibited by a betaine/GABA transporter-1 (GABA transporter-2: GAT2) inhibitor, NNC 05-2090. In this study, we investigated whether memory amelioration by betaine was mediated by the GABAergic neuronal system. Adult male mice were co-administered betaine and GABA receptor antagonists after WIRS. We also examined whether memory impairment after WIRS was attenuated by GABA receptor agonists. The memory functions were evaluated using a novel object recognition test 3-6 days after WIRS and/or the step-down type passive avoidance test at 7-8 days. The co-administration of the GABA A receptor antagonist bicuculline (1mg/kg) or the GABA B receptor antagonist phaclofen (10mg/kg) 1h after WIRS suppressed the memory-improving effects induced by betaine. Additionally, the administration of the GABA A receptor agonist muscimol (1mg/kg) or the GABA B receptor agonist baclofen (10mg/kg) 1h after WIRS attenuated memory impairments. These results were similar to the data observed with betaine. The treatment with betaine after WIRS significantly decreased the expression of GABA transaminase, and this effect was partially blocked by NNC 05-2090 in the hippocampus. WIRS caused a transient increase in hippocampal GABA levels and the changes after WIRS were not affected by betaine treatment in an in vivo microdialysis study. These results suggest that the beneficial effects of betaine may be mediated in part by changing the GABAergic neuronal system. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Experimental Determination of Solubilities of Tri-calcium Di-Citrate Tetrahydrate [Ca 3[C 3H 5O(COO) 3] 2•4H 2O] Earlandite in NaCl and MgCl 2 Solutions to High Ionic Strengths and Its Pitzer Model: Applications to Nuclear Waste Isolation and Other Low Temperature Environments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xiong, Yongliang; Kirkes, Leslie Dawn; Westfall, Terry

    In this study, solubility measurements on tri-calcium di-citrate tetrahydrate [Ca 3[C 3H 5O(COO) 3]2•4H 2O, abbreviated as Ca 3[Citrate] 2•4H 2O] as a function of ionic strength are conducted in NaCl solutions up to I = 5.0 mol•kg –1 and in MgCl 2 solutions up to I = 7.5 mol•kg –1, at room temperature (22.5 ± 0.5°C). The solubility constant (log Kmore » $$0\\atop{sp}$$) for Ca 3[Citrate] 2•4H 2O and formation constant (logβ$$0\\atop{1}$$) for Ca[C 3H 5O(COO) 3] –Ca 3[C 3H 5O(COO) 3] 2•4H 2O (earlandite) = 3Ca 2+ + 2[C 3H 5O(COO) 3] 3– + 4H 2O (1) Ca 2+ + [C 3H 5O(COO) 3] 3– = Ca[C 3H 5O(COO) 3] – (2) are determined as –18.11 ± 0.05 and 4.97 ± 0.05, respectively, based on the Pitzer model with a set of Pitzer parameters describing the specific interactions in NaCl and M gCl 2 media.« less

  9. Extracellular cyclic ADP-ribose potentiates ACh-induced contraction in bovine tracheal smooth muscle.

    PubMed

    Franco, L; Bruzzone, S; Song, P; Guida, L; Zocchi, E; Walseth, T F; Crimi, E; Usai, C; De Flora, A; Brusasco, V

    2001-01-01

    Cyclic ADP-ribose (cADPR), a universal calcium releaser, is generated from NAD(+) by an ADP-ribosyl cyclase and is degraded to ADP-ribose by a cADPR hydrolase. In mammals, both activities are expressed as ectoenzymes by the transmembrane glycoprotein CD38. CD38 was identified in both epithelial cells and smooth myocytes isolated from bovine trachea. Intact tracheal smooth myocytes (TSMs) responded to extracellular cADPR (100 microM) with an increase in intracellular calcium concentration ([Ca(2+)](i)) both at baseline and after acetylcholine (ACh) stimulation. The nonhydrolyzable analog 3-deaza-cADPR (10 nM) elicited the same effects as cADPR, whereas the cADPR antagonist 8-NH(2)-cADPR (10 microM) inhibited both basal and ACh-stimulated [Ca(2+)](i) levels. Extracellular cADPR or 3-deaza-cADPR caused a significant increase of ACh-induced contraction in tracheal smooth muscle strips, whereas 8-NH(2)-cADPR decreased it. Tracheal mucosa strips, by releasing NAD(+), enhanced [Ca(2+)](i) in isolated TSMs, and this increase was abrogated by either NAD(+)-ase or 8-NH(2)-cADPR. These data suggest the existence of a paracrine mechanism whereby mucosa-released extracellular NAD(+) plays a hormonelike function and cADPR behaves as second messenger regulating calcium-related contractility in TSMs.

  10. Myofibril ATPase activity of cardiac and skeletal muscle of exhaustively exercised rats.

    PubMed

    Belcastro, A N; Turcotte, R; Rossiter, M; Secord, D; Maybank, P E

    1984-01-01

    The activation characteristics of Mg-ATP and Ca2+ on cardiac and skeletal muscle myofibril ATPase activity were studied in rats following a run to exhaustion. In addition, the effect of varying ionic strength was determined on skeletal muscle from exhausted animals. The exhausted group (E) ran at a speed of 25 m min-1 with an 8% incline. Myofibril ATPase activities for control (C) and E were determined with 1, 3 and 5 mM Mg-ATP and 1 and 10 microM Ca2+ at pH 7.0 and 30 degrees C. For control skeletal muscle, at 1 and 10 microM Ca2+, there was an increase in ATPase activity from 1 to 5 mM Mg-ATP (P less than 0.05). For E animals the myofibril ATPase activities at 10 microM Ca2+ and all Mg-ATP concentrations were similar to C (P greater than 0.05). At 1.0 microM Ca2+ and all Mg-ATP concentrations were similar to C (P greater than 0.05). At 1.0 microM Ca2+ the activities at 3 and 5 mM Mg-ATP were greater for the E animals (P less than 0.05). Increasing KCl concentrations resulted in greater inhibition for E animals. With cardiac muscle, the myofibril ATPase activities at 1.0 microM free Ca2+ were lower for E at all Mg-ATP levels (P less than 0.05). In contrast, at 10 microM Ca2+, the E group exhibited an elevated myofibril ATPase activity. The results indicate that Mg-ATP and Ca2+ activation of cardiac and skeletal muscle myofibril ATPase is altered with exhaustive exercise.

  11. Reduction of perifusate magnesium alters inotropic response of papillary muscle to ion channel modulators.

    PubMed

    Manju, L; Nair, R Renuka

    2005-09-01

    Magnesium has a significant role in the regulation of ion transport. Marginal deficiency of Mg can therefore affect myocardial excitability and contractility. This study was taken up with the objective of examining the inotropic response of the myocardium to variation in extracellular [Mg]o and identifying the ion channels and pumps mediating the inotropic changes. Electrically stimulated rat papillary muscle was used as the experimental model and mechanical changes were recorded using a physiograph. Channel specific antagonists were used to identify the channels mediating the functional changes. Diastolic Ca2+ levels were determined in isolated myocytes by the ratiometric method using the fluorescent indicator Fura2-AM. A negative association was observed between the level of [Mg]o and force of contraction, with a peak at 0.48 mM Mg. The force of contraction in Mg deficient medium (0.48 mM) was 158% of control (1.2 mM Mg) (p < 0.001). Inotropic response to the L-type channel antagonist (verapamil-1 microm) and NaK ATPase inhibitor (Ouabain-0.3 mM) was augmented in Mg deficiency (p < 0.005), indicating activation of the channel and the pump. The response to T-type channel inhibitor (NiCl2-40 microM) was attenuated in Mg deficiency (p < 0.05). The response to the sarcoplasmic reticular Ca pump inhibitor (caffeine-10 mM) and the SR Ca2+ release channel inhibitor (ryanodine-1 microM) were not significantly affected by Mg deficiency. Diastolic level of Ca2+ increased with a decrease in Mg (p < 0.05). The observations of the study lead to the conclusion that the positive inotropic response in Mg deficiency is mediated by an increase in basal Ca2+ combined with Ca-induced-Ca release consequent to Ca2+ influx through L-type Ca channel. Variation in sensitivity to Ca channel blockers and NaK ATPase inhibitor in Mg deficiency can have pharmacological implications.

  12. Pulmonary artery smooth muscle cell [Ca2+]i and contraction: responses to diphenyleneiodonium and hypoxia.

    PubMed

    Zhang, F; Carson, R C; Zhang, H; Gibson, G; Thomas, H M

    1997-09-01

    To investigate mechanisms of inhibition of hypoxic pulmonary vasoconstriction (HPV), we studied pulmonary artery smooth muscle cell (PASMC) responses to hypoxia, utilizing diphenyleneiodonium (DPI), which blocks HPV. We measured cell contraction in primary cultures of rat PASMC grown on collagen gels and cytosolic free Ca2+ concentration ([Ca2+]i) in PASMC grown on glass. DPI (5 and 20 microM) caused contraction of PASMC and increased [Ca2+]i. Omission of extracellular Ca2+ diminished the DPI-induced PASMC contraction and greatly reduced the increase in [Ca2+]i. DPI substantially inhibited KCl-induced PASMC contraction (1 microM DPI) and the increase in [Ca2+]i (5 microM DPI). Severe hypoxia contracted PASMC and quadrupled [Ca2+]i. DPI, 1 microM, substantially inhibited hypoxic contraction, but neither 1 nor 5 microM DPI diminished the hypoxia-induced increase in [Ca2+]i, which was greatly attenuated by 20 microM DPI. These data show 1) that DPI increases [Ca2+]i, accounting for DPI-induced PASMC contraction and 2) that 1 and 5 microM DPI inhibit the hypoxia-induced contraction but not the hypoxia-induced increase in [Ca2+]i, suggesting that DPI inhibits hypoxic PASMC contraction downstream of the Ca2+ signal by desensitizing the contractile apparatus and indicating a potential control point for modulation of HPV.

  13. Synthesis and structural characterization of the hexagonal anti-perovskite Na{sub 2}CaVO{sub 4}F

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Green, Robert L., E-mail: rgreen@flpoly.org; Avdeev, Maxim; School of Chemistry, The University of Sydney, Sydney, NSW 2006

    The structural details of the ordered hexagonal oxyfluoride Na{sub 2}CaVO{sub 4}F prepared by solid-state synthesis using stoichiometric amounts of V{sub 2}O{sub 5}, CaCO{sub 3}, Na{sub 2}CO{sub 3} and NaF were characterized using high-resolution neutron powder diffraction. The structural changes between 25 °C and 750 °C revealed that the two structural subunits in this material behave different when heated: there is an expansion of the face-shared FNa{sub 4}Ca{sub 2} octahedra while the VO{sub 4} tetrahedra due to increased thermal disorder reveal marginal bond contractions. Bond valences and the global instability index point to significant structural disorder at 750 °C. - Graphicalmore » abstract: The structure of the novel oxyfluoride Na{sub 2}CaVO{sub 4}F is studied at room temperature and high-temperatures. The structure can be viewed as layers of compression and elongation of polyhedral subunits, which change as a function of temperature. - Highlights: • The novel oxyfluoride, Na{sub 2}CaVO{sub 4}F, is synthesized via solid-state method. • High-resolution neutron diffraction data is used to analyze the structure of Na{sub 2}CaVO{sub 4}F. • Structural subunits exhibit expansion and contraction with increasing temperature. • Higher temperatures increase instability within the structure of Na{sub 2}CaVO{sub 4}F.« less

  14. Investigations on FCAM-III (Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36): A new homologue of the aenigmatite structure-type in the system CaO-MgO-Fe2O3-Al2O3

    NASA Astrophysics Data System (ADS)

    Zöll, Klaus; Kahlenberg, Volker; Krüger, Hannes; Tropper, Peter

    2018-02-01

    In the course of a systematic study of a part of the quaternary system Fe2O3-CaO-Al2O3-MgO (FCAM) the previously unknown compound Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 (FCAM-III) has been synthesized. By analogy with the so-called SFCA series [1-5], our investigation in the system of FCAM shows the existence of a stoichiometric homologous series M14+6nO20+8n, where M = Fe, Ca, Al, Mg and n = 1 or 2. In air, we can prove the formation of coexisting FCAM-III and FCAM-I solid solutions at 1400 °C. By increasing the temperature up to 1425 °C FCAM-I disappears completely and FCAM-III co-exists with magnesiumferrite and a variety of calcium iron oxides. At 1450 °C FCAM-III breaks down to a mixture of FCAM-I again as well as magnesioferrite and melt. Small single-crystals of FCAM-III up to 35 μm in size could be retrieved from the 1425 °C experiment and were subsequently characterized using electron microprobe analysis and synchroton X-ray single-crystal diffraction. Finally the Fe2+/Fetot ratio was calculated from the total iron content based on the crystal-chemical formula obtained from EMPA measurements and charge balance considerations. FCAM-III or Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 has a triclinic crystal structure (space group P 1 ̅). The basic crystallographic data are: a = 10.223(22) Å, b = 10.316(21) Å, c = 14.203(15) Å, α = 93.473(50)°, β = 107.418(67)°, γ = 109.646(60)°, V = 1323.85(2) ų, Z = 1. Using Schreinemaker's technique to analyze the phase relations in the system Fe2O3-CaO-Al2O3-MgO it was possible to obtain the semi-quantitative stability relations between the participating phases and construct a topologically correct phase sequence as a function of T and fO2. The analysis shows that Ca2Al0.5Fe1.5O5 (C2A0.25F0.75) and CaAl1.5Fe2.5O7 (CA0.75F1.25) with higher calculated Fe2+ contents are preferably formed at lower oxygen fugacity and react to CaAl0.5Fe1.5O4 (CA0.25F0.75) by increasing fO2. Spinel-type magnesium-aluminium-ferrite (Mg,Fe2+)Fe3+1.25Al0.75O4 or (MA0.375F0.625) is the typical phase which occurs at high temperature (1400 °C).

  15. Neural Network Perception for Mobile Robot Guidance

    DTIC Science & Technology

    1992-02-16

    of this dissertation, the perceptual process - ing module (See Figure 1.1). The job of the perceptual processing module is to transform the information...organization in a perceptual net- work ", Computer, Vol. 21 pp. 105-117. [Linsker, 1989] Linsker, R. (1989) Designing a sensory processing system: What can...Dean A. Pomerleau Support for this work has come from DARPA, under contracts DACA76-35-C-0019, DACA76-85-C-0003, DACA76-85-C-0002, DACA76-89-C-0014 and

  16. Tension Recovery following Ramp-Shaped Release in High-Ca and Low-Ca Rigor Muscle Fibers: Evidence for the Dynamic State of AMADP Myosin Heads in the Absence of ATP

    PubMed Central

    Sugi, Haruo; Yamaguchi, Maki; Ohno, Tetsuo; Kobayashi, Takakazu; Chaen, Shigeru; Okuyama, Hiroshi

    2016-01-01

    During muscle contraction, myosin heads (M) bound to actin (A) perform power stroke associated with reaction, AMADPPi → AM + ADP + Pi. In this scheme, A • M is believed to be a high-affinity complex after removal of ATP. Biochemical studies on extracted protein samples show that, in the AM complex, actin-binding sites are located at both sides of junctional peptide between 50K and 20K segments of myosin heavy chain. Recently, we found that a monoclonal antibody (IgG) to the junctional peptide had no effect on both in vitro actin-myosin sliding and skinned muscle fiber contraction, though it covers the actin-binding sites on myosin. It follows from this that, during muscle contraction, myosin heads do not pass through the static rigor AM configuration, determined biochemically and electron microscopically using extracted protein samples. To study the nature of AM and AMADP myosin heads, actually existing in muscle, we examined mechanical responses to ramp-shaped releases (0.5% of Lo, complete in 5ms) in single skinned rabbit psoas muscle fibers in high-Ca (pCa, 4) and low-Ca (pCa, >9) rigor states. The fibers exhibited initial elastic tension drop and subsequent small but definite tension recovery to a steady level. The tension recovery was present over many minutes in high-Ca rigor fibers, while it tended to decrease quickly in low-Ca rigor fibers. EDTA (10mM, with MgCl2 removed) had no appreciable effect on the tension recovery in high-Ca rigor fibers, while it completely eliminated the tension recovery in low-Ca rigor fibers. These results suggest that the AMADP myosin heads in rigor muscle have long lifetimes and dynamic properties, which show up as the tension recovery following applied release. Possible AM linkage structure in muscle is discussed in connection with the X-ray diffraction pattern from contracting muscle, which is intermediate between resting and rigor muscles. PMID:27583360

  17. Tension Recovery following Ramp-Shaped Release in High-Ca and Low-Ca Rigor Muscle Fibers: Evidence for the Dynamic State of AMADP Myosin Heads in the Absence of ATP.

    PubMed

    Sugi, Haruo; Yamaguchi, Maki; Ohno, Tetsuo; Kobayashi, Takakazu; Chaen, Shigeru; Okuyama, Hiroshi

    2016-01-01

    During muscle contraction, myosin heads (M) bound to actin (A) perform power stroke associated with reaction, AMADPPi → AM + ADP + Pi. In this scheme, A • M is believed to be a high-affinity complex after removal of ATP. Biochemical studies on extracted protein samples show that, in the AM complex, actin-binding sites are located at both sides of junctional peptide between 50K and 20K segments of myosin heavy chain. Recently, we found that a monoclonal antibody (IgG) to the junctional peptide had no effect on both in vitro actin-myosin sliding and skinned muscle fiber contraction, though it covers the actin-binding sites on myosin. It follows from this that, during muscle contraction, myosin heads do not pass through the static rigor AM configuration, determined biochemically and electron microscopically using extracted protein samples. To study the nature of AM and AMADP myosin heads, actually existing in muscle, we examined mechanical responses to ramp-shaped releases (0.5% of Lo, complete in 5ms) in single skinned rabbit psoas muscle fibers in high-Ca (pCa, 4) and low-Ca (pCa, >9) rigor states. The fibers exhibited initial elastic tension drop and subsequent small but definite tension recovery to a steady level. The tension recovery was present over many minutes in high-Ca rigor fibers, while it tended to decrease quickly in low-Ca rigor fibers. EDTA (10mM, with MgCl2 removed) had no appreciable effect on the tension recovery in high-Ca rigor fibers, while it completely eliminated the tension recovery in low-Ca rigor fibers. These results suggest that the AMADP myosin heads in rigor muscle have long lifetimes and dynamic properties, which show up as the tension recovery following applied release. Possible AM linkage structure in muscle is discussed in connection with the X-ray diffraction pattern from contracting muscle, which is intermediate between resting and rigor muscles.

  18. Muscle Contraction Arrests Tumor Growth

    DTIC Science & Technology

    2006-09-01

    AD_________________ Award Number: W81XWH-05-1-0464 TITLE: Muscle Contraction Arrests Tumor Growth...DATE 01-09-2006 2. REPORT TYPE Annual 3. DATES COVERED 1 Sep 2005 – 31 Aug 2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Muscle ... Contraction Arrests Tumor Growth 5b. GRANT NUMBER W81XWH-05-1-0464 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kim Westerlind, Ph.D. 5d. PROJECT NUMBER

  19. Role of endothelin-converting enzyme, chymase and neutral endopeptidase in the processing of big ET-1, ET-1(1-21) and ET-1(1-31) in the trachea of allergic mice.

    PubMed

    De Campo, Benjamin A; Goldie, Roy G; Jeng, Arco Y; Henry, Peter J

    2002-08-01

    The present study examined the roles of endothelin-converting enzyme (ECE), neutral endopeptidase (NEP) and mast cell chymase as processors of the endothelin (ET) analogues ET-1(1-21), ET-1(1-31) and big ET-1 in the trachea of allergic mice. Male CBA/CaH mice were sensitized with ovalbumin (10 microg) delivered intraperitoneal on days 1 and 14, and exposed to aerosolized ovalbumin on days 14, 25, 26 and 27 (OVA mice). Mice were killed and the trachea excised for histological analysis and contraction studies on day 28. Tracheae from OVA mice had 40% more mast cells than vehicle-sensitized mice (sham mice). Ovalbumin (10 microg/ml) induced transient contractions (15+/-3% of the C(max)) in tracheae from OVA mice. The ECE inhibitor CGS35066 (10 microM) inhibited contractions induced by big ET-1 (4.8-fold rightward shift of dose-response curve; P<0.05), but not those induced by either ET-1(1-21) or ET-1(1-31). The chymase inhibitors chymostatin (10 microM) and Bowman-Birk inhibitor (10 microM) had no effect on contractions induced by any of the ET analogues used. The NEP inhibitor CGS24592 (10 microM) inhibited contractions induced by ET-1(1-31) (6.2-fold rightward shift; P<0.05) but not ET-1(1-21) or big ET-1. These data suggest that big ET-1 is processed predominantly by a CGS35066-sensitive ECE within allergic airways rather than by mast cell-derived proteases such as chymase. If endogenous ET-1(1-31) is formed within allergic airways, it is likely to undergo further conversion by NEP to more active products.

  20. 11. 'Erection Plan, 1 208'101/2' C. to C. End ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. 'Erection Plan, 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing Sacramento River, Pacific System, Southern Pacific Company, The Phoenix Bridge Co., C.O. 836D, Drawing No. 13, Scale 1/8' = 1'0', Engineer, B.M. Krohn, Draftsman, W.L. Clegg, Date, May 25th 1901' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  1. Influence of Li3BO3 additives on the Li+ conductivity and stability of Ca/Ta-substituted Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 electrolytes

    NASA Astrophysics Data System (ADS)

    Zhang, L. C.; Yang, J. F.; Gao, Y. X.; Wang, X. P.; Fang, Q. F.; Chen, C. H.

    2017-07-01

    The cubic Ca/Ta-substituted Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 (LLCZTO) electrolytes were synthesized at 800 °C with Li3BO3 as additives. The optimal amount of Li3BO3 and its influences on the microstructure, crystal structures, Li+ conductivity and the stability of the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 were studied by SEM, XRD and EIS. Among all the samples, when the molar ratio of Li3BO3 to the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 is 4:5, the highest Li+ conductivity of 1.33 × 10-4 S cm-1 at 30 °C is obtained. When the LLCZTO samples are exposed in air, the Li+ conductivity is deteriorated possibly owing to the side reactions between the LLCZTO and the H2O or CO2 in the air. The Li3BO3 addition can alleviate such deterioration of the Li+ conductivity.

  2. Cardioprotective effect of Sida rhomboidea. Roxb extract against isoproterenol induced myocardial necrosis in rats.

    PubMed

    Thounaojam, Menaka C; Jadeja, Ravirajsinh N; Ansarullah; Karn, Sanjay S; Shah, Jigar D; Patel, Dipak K; Salunke, Sunita P; Padate, Geeta S; Devkar, Ranjitsinh V; Ramachandran, A V

    2011-05-01

    The present study investigates cardioprotective effect of Sida rhomboidea. Roxb (SR) extract on heart weight, plasma lipid profile, plasma marker enzymes, lipid peroxidation, endogenous enzymatic and non-enzymatic antioxidants and membrane bound ATPases against isoproterenol (IP) induced myocardial necrosis (MN) in rats. Rats treated with IP (85 mg/kg, s.c.) recorded significant (p<0.05) increment in heart weight, plasma lipid profile, plasma marker enzymes of cardiac damage, cardiac lipid peroxidation (LPO) and activity levels of Ca(+2) ATPase whereas there was significant (p<0.05) decrease in plasma HDL, cardiac endogenous enzymatic and non-enzymatic antioxidants, Na(+)-K(+) ATPase and Mg(+2) ATPase. Pre-treatment with SR extract (400 mg/kg per day, p.o.) for 30 consecutive days followed by IP injections on days 29th and 30th, showed significant (p<0.05) decrease in heart weight, plasma lipid profile, plasma marker enzymes of cardiac damage, cardiac lipid peroxidation, Ca(+2) ATPase and significant increase in plasma HDL, cardiac endogenous enzymatic and non-enzymatic antioxidants, Na(+)-K(+) ATPase and Mg(+2) ATPase compared to IP treated group. Hence, this study is the first scientific report on cardioprotective effect of SR against IP induced MN in rats. Copyright © 2010 Elsevier GmbH. All rights reserved.

  3. Mibefradil reduces blood glucose concentration in db/db mice

    PubMed Central

    Lu, Yujie; Long, Min; Zhou, Shiwen; Xu, Zihui; Hu, Fuquan; Li, Ming

    2014-01-01

    OBJECTIVE: Numerous recent studies suggest that abnormal intracellular calcium concentration ([Ca2+]i) is a common defect in diabetic animal models and patients. Abnormal calcium handling is an important mechanism in the defective pancreatic β-cell function in type 2 diabetes. T-type Ca2+ channel antagonists lower blood glucose in type 2 diabetes, but the mechanism remains unknown. METHODS: We examined the effect of the Ca2+ channel antagonist mibefradil on blood glucose in male db/db mice and phenotypically normal heterozygous mice by intraperitoneal injection. RESULTS: Mibefradil (15 mg/kg, i.p., b.i.d.) caused a profound reduction of fasting blood glucose from 430.92±20.46 mg/dl to 285.20±5.74 mg/dl in three days. The hypoglycemic effect of mibefradil was reproduced by NNC 55-0396, a compound structurally similar to mibefradil but more selective for T-type Ca2+ channels, but not by the specific L-type Ca2+ channel blocker nicardipine. Mibefradil did not show such hypoglycemic effects in heterozygous animals. In addition, triglycerides, basal insulin and food intake were significantly decreased by mibefradil treatment in the db/db mice but not in the controls. Western blot analysis, immunohistochemistry and immunofluorescence staining showed a significantly increased expression of T-type Ca2+ channel α-subunits Cav3.1 and Cav3.2 in liver and brain tissues from db/db mice compared to those from heterozygous animals. CONCLUSIONS: Collectively, these results suggest that T-type Ca2+ channels are potential therapeutic targets for antidiabetic drugs. PMID:24473561

  4. Long Term Ablation of Protein Kinase A (PKA)-mediated Cardiac Troponin I Phosphorylation Leads to Excitation-Contraction Uncoupling and Diastolic Dysfunction in a Knock-in Mouse Model of Hypertrophic Cardiomyopathy*

    PubMed Central

    Dweck, David; Sanchez-Gonzalez, Marcos A.; Chang, Audrey N.; Dulce, Raul A.; Badger, Crystal-Dawn; Koutnik, Andrew P.; Ruiz, Edda L.; Griffin, Brittany; Liang, Jingsheng; Kabbaj, Mohamed; Fincham, Frank D.; Hare, Joshua M.; Overton, J. Michael; Pinto, Jose R.

    2014-01-01

    The cardiac troponin I (cTnI) R21C (cTnI-R21C) mutation has been linked to hypertrophic cardiomyopathy and renders cTnI incapable of phosphorylation by PKA in vivo. Echocardiographic imaging of homozygous knock-in mice expressing the cTnI-R21C mutation shows that they develop hypertrophy after 12 months of age and have abnormal diastolic function that is characterized by longer filling times and impaired relaxation. Electrocardiographic analyses show that older R21C mice have elevated heart rates and reduced cardiovagal tone. Cardiac myocytes isolated from older R21C mice demonstrate that in the presence of isoproterenol, significant delays in Ca2+ decay and sarcomere relaxation occur that are not present at 6 months of age. Although isoproterenol and stepwise increases in stimulation frequency accelerate Ca2+-transient and sarcomere shortening kinetics in R21C myocytes from older mice, they are unable to attain the corresponding WT values. When R21C myocytes from older mice are treated with isoproterenol, evidence of excitation-contraction uncoupling is indicated by an elevation in diastolic calcium that is frequency-dissociated and not coupled to shorter diastolic sarcomere lengths. Myocytes from older mice have smaller Ca2+ transient amplitudes (2.3-fold) that are associated with reductions (2.9-fold) in sarcoplasmic reticulum Ca2+ content. This abnormal Ca2+ handling within the cell may be attributed to a reduction (2.4-fold) in calsequestrin expression in conjunction with an up-regulation (1.5-fold) of Na+-Ca2+ exchanger. Incubation of permeabilized cardiac fibers from R21C mice with PKA confirmed that the mutation prevents facilitation of mechanical relaxation. Altogether, these results indicate that the inability to enhance myofilament relaxation through cTnI phosphorylation predisposes the heart to abnormal diastolic function, reduced accessibility of cardiac reserves, dysautonomia, and hypertrophy. PMID:24973218

  5. The effect of gallic acid on cytotoxicity, Ca(2+) homeostasis and ROS production in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes.

    PubMed

    Hsu, Shu-Shong; Chou, Chiang-Ting; Liao, Wei-Chuan; Shieh, Pochuen; Kuo, Daih-Huang; Kuo, Chun-Chi; Jan, Chung-Ren; Liang, Wei-Zhe

    2016-05-25

    Gallic acid, a polyhydroxylphenolic compound, is widely distributed in various plants, fruits and foods. It has been shown that gallic acid passes into blood brain barrier and reaches the brain tissue of middle cerebral artery occlusion rats. However, the effect of gallic acid on Ca(2+) signaling in glia cells is unknown. This study explored whether gallic acid affected Ca(2+) homeostasis and induced Ca(2+)-associated cytotoxicity in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes. Gallic acid (20-40 μM) concentration-dependently induced cytotoxicity and intracellular Ca(2+) level ([Ca(2+)]i) increases in DBTRG-05MG cells but not in CTX TNA2 cells. In DBTRG-05MG cells, the Ca(2+) response was decreased by half by removal of extracellular Ca(2+). In Ca(2+)-containing medium, gallic acid-induced Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (2-APB, econazole and SKF96365). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin abolished gallic acid-induced [Ca(2+)]i increases. Conversely, incubation with gallic acid also abolished thapsigargin-induced [Ca(2+)]i increases. Inhibition of phospholipase C with U73122 abolished gallic acid-induced [Ca(2+)]i increases. Gallic acid significantly caused cytotoxicity in DBTRG-05MG cells, which was partially prevented by prechelating cytosolic Ca(2+) with BAPTA-AM. Moreover, gallic acid activated mitochondrial apoptotic pathways that involved ROS production. Together, in DBTRG-05MG cells but not in CTX TNA2 cells, gallic acid induced [Ca(2+)]i increases by causing Ca(2+) entry via 2-APB, econazole and SKF96365-sensitive store-operated Ca(2+) entry, and phospholipase C-dependent release from the endoplasmic reticulum. This Ca(2+) signal subsequently evoked mitochondrial pathways of apoptosis that involved ROS production. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Calcium Balance in Mature Rats Exposed to a Space Flight Model

    NASA Technical Reports Server (NTRS)

    Navidi, Meena; Evans, J.; Looft-Wilson, R.; Wolinsky, I.; Arnaud, S. B.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Depressed intestinal calcium absorption (Ca abs.) and lower circulating 1,25-dihydroxyvitamin D (1,25-D) are associated with less positive calcium balance in young 200 g rats exposed to skeletal unloading by hind-limb suspension than controls (C) . To determine the effect of the space flight model on calcium balance in mature rats, we exposed 6 mo. old males weighing 492 +/- 12g to the model for 4 weeks (S) and compared Ca in the diet, urine, feces and 1,25-D in S and C. Rats were fed diets containing sufficient Ca to satisfy metabolic needs, but not to cause deficiency (0.1%). At the end of 4 weeks, there was a 5 percent weight loss in S, but not in C; and no differences in dietary, urine (UCa) or fecal Ca (FCa) in S and C. Net Ca abs. (0.1 vs 2.7 %), 1,25-D (50 +/- 16 vs 47 +/- 14 pg/ml) and Ca balances (-1.8 +/- 4 vs -1.0 +/- 2.9 mg/d) were similar in C and S. UCa loss was added to the model by inducing calciuria with 8% salt diets (HiNa). A 4-fold increase in UCa in C and S was transiently higher in S than C after 1 week. After 4 weeks, loss in BW was greater in S than C, Ca abs was higher in C than S (32 +/- 10 vs 3.5 +/- 16%, p less than .05), 1,25-D greater in S than C (98 +/- 15 vs 79 +/- 14 pg/ml p less than .05) and Ca balance less in S than C (-5.2 +/- 4 vs -1.7 +/- 2 mg/d, p less than .05). Ca balance in the mature rat is unaffected by the space flight model unless calciuria intervenes and reveals the failure of the intestine to enhance Ca abs. and compensate for UCa loss.

  7. Reperfusion response changes induced by repeated, sustained contractions in normal human masseter muscle.

    PubMed

    Aizawa, Shigeru; Tsukiyama, Yoshihiro; Koyano, Kiyoshi; Clark, Glenn T

    2002-07-01

    The purpose was to evaluate the intramuscular reperfusion response characteristics associated with repeated isometric contractions in normal human masseter. Intramuscular blood volume was quantified with a near-infrared spectroscopic device that measured the total haemoglobin (Hb) concentration in the muscle. Electromyographic (EMG) activity from the masseter and total bite forces were also recorded. Sixteen healthy volunteers, eight females and eight males, without masticatory muscle pain participated. They were asked first to clench their teeth for as long as possible at 50% of their maximum voluntary contraction (MVC). This was followed by a 60s rest and then immediately by a standard clenching task (50% MVC for 30s) and a 60s recovery period, immediately after which they were asked to repeat exactly the same procedure, with a final 5 min recovery period after the second 30s contraction. Bite force, EMG and Hb concentration were measured continuously and the duration of the two endurance tasks and the amplitudes of all recorded signals were compared (first trial versus second trial). Specifically, the difference between the lowest Hb (trough) seen during the standardised 30s contractions and the highest (peak) seen just after them was assessed. The trough-to-peak difference in Hb concentration of the second standard contraction task was significantly smaller than that of the first standard task (P<0.05, paired t-test). These data show that with sustained effort the post-contraction vasodilatory reperfusion responses of the human masseter are diminished, suggesting a progressive desensitisation of the vasodilatory system.

  8. Rho-dependent kinase is involved in agonist-activated calcium entry in rat arteries

    PubMed Central

    Ghisdal, Philippe; Vandenberg, Greet; Morel, Nicole

    2003-01-01

    The present study was aimed at investigating whether, besides its pivotal role in Ca2+-independent contraction of smooth muscle, Rho-kinase is involved in the mechanisms underlying the Ca2+ signal activated by noradrenaline in arteries. In rat aorta and mesenteric artery, the Rho-kinase inhibitor Y-27632 (10 μM) completely relaxed the contraction evoked by noradrenaline (1 μM) and simultaneously inhibited the Ca2+ signal by 54 ± 1 % (mesenteric artery) and 71 ± 15 % (aorta), and the cell membrane depolarisation by 56 ± 11 % (mesenteric artery). A similar effect was observed in arteries contracted by AlF4−, while in KCl-contracted arteries, Y-27632 decreased tension without changing cytosolic Ca2+. The same effects were observed with another inhibitor of Rho-kinase (HA1077) but not with an inhibitor of protein kinase C (Ro-31–8220). Effects of Y-27632 were not prevented by incubating the artery in 25 mM KCl, with K+ channel blockers or with the Ca2+ channel blocker nimodipine. Y-27632 did not affect either the increase in the production of inositol phosphates activated by noradrenaline, or the release of Ca2+ from non-mitochondrial stores evoked by InsP3 in permeabilised aortic cells, or the Ca2+ signals evoked by thapsigargin or caffeine. The capacitative Ca2+ entry activated by thapsigargin was not impaired by Y-27632, but the entry of Ba2+ activated by noradrenaline in the presence of nimodipine was blocked by 10 μM Y-27632. These results indicate that Rho-kinase is involved in noradrenaline activation of a Ca2+ entry distinct from voltage- or store-operated channels in rat arteries. PMID:12853654

  9. The contribution of Ca2+ signaling and Ca2+ sensitivity to the regulation of airway smooth muscle contraction is different in rats and mice.

    PubMed

    Bai, Yan; Sanderson, Michael J

    2009-06-01

    To determine the relative contributions of Ca(2+) signaling and Ca(2+) sensitivity to the contractility of airway smooth muscle cells (SMCs), we compared the contractile responses of mouse and rat airways with the lung slice technique. Airway contraction was measured by monitoring changes in airway lumen area with phase-contrast microscopy, whereas changes in intracellular calcium concentration ([Ca(2+)](i)) of the SMCs were recorded with laser scanning microscopy. In mice and rats, methacholine (MCh) or serotonin induced concentration-dependent airway contraction and Ca(2+) oscillations in the SMCs. However, rat airways demonstrated greater contraction compared with mice, in response to agonist-induced Ca(2+) oscillations of a similar frequency. Because this indicates that rat airway SMCs have a higher Ca(2+) sensitivity compared with mice, we examined Ca(2+) sensitivity with Ca(2+)-permeabilized airway SMCs in which the [Ca(2+)](i) was experimentally controlled. In the absence of agonists, high [Ca(2+)](i) induced a sustained contraction in rat airways but only a transient contraction in mouse airways. This sustained contraction of rat airways was relaxed by Y-23672, a Rho kinase inhibitor, but not affected by GF-109203X, a PKC inhibitor. The subsequent exposure of Ca(2+)-permeabilized airway SMCs, with high [Ca(2+)](i), to MCh elicited a further contraction of rat airways and initiated a sustained contraction of mouse airways, without changing the [Ca(2+)](i) of the SMCs. Collectively, these results indicate that airway SMCs of rats have a substantially higher innate Ca(2+) sensitivity than mice and that this strongly influences the transduction of the frequency of Ca(2+) oscillations into the contractility of airway SMCs.

  10. Tramadol state-dependent memory: involvement of dorsal hippocampal muscarinic acetylcholine receptors.

    PubMed

    Jafari-Sabet, Majid; Jafari-Sabet, Ali-Reza; Dizaji-Ghadim, Ali

    2016-08-01

    The effects on tramadol state-dependent memory of bilateral intradorsal hippocampal (intra-CA1) injections of physostigmine, an acetylcholinesterase inhibitor, and atropine, a muscarinic acetylcholine receptor antagonist, were examined in adult male NMRI mice. A single-trial step-down passive avoidance task was used for the assessment of memory retention. Post-training intra-CA1 administration of an atypical μ-opioid receptor agonist, tramadol (0.5 and 1 μg/mouse), dose dependently impaired memory retention. Pretest injection of tramadol (0.5 and 1 μg/mouse, intra-CA1) induced state-dependent retrieval of the memory acquired under the influence of post-training tramadol (1 μg/mouse, intra-CA1). A pretest intra-CA1 injection of physostigmine (1 μg/mouse) reversed the memory impairment induced by post-training administration of tramadol (1 μg/mouse, intra-CA1). Moreover, pretest administration of physostigmine (0.5 and 1 μg/mouse, intra-CA1) with an ineffective dose of tramadol (0.25 μg/mouse, intra-CA1) also significantly restored retrieval. Pretest administration of physostigmine (0.25, 0.5, and 1 μg/mouse, intra-CA1) by itself did not affect memory retention. A pretest intra-CA1 injection of the atropine (1 and 2 μg/mouse) 5 min before the administration of tramadol (1 μg/mouse, intra-CA1) dose dependently inhibited tramadol state-dependent memory. Pretest administration of atropine (0.5, 1, and 2 μg/mouse, intra-CA1) by itself did not affect memory retention. It can be concluded that dorsal hippocampal muscarinic acetylcholine receptor mechanisms play an important role in the modulation of tramadol state-dependent memory.

  11. Estimating the Probability of a Diffusing Target Encountering a Stationary Sensor.

    DTIC Science & Technology

    1985-07-01

    7 RD-R1577 6- 44 ESTIMATING THE PROBABILITY OF A DIFFUSING TARGET i/i ENCOUNTERING R STATIONARY SENSOR(U) NAVAL POSTGRADUATE U SCHOOL MONTEREY CA...8217,: *.:.; - -*.. ,’.-,:;;’.’.. ’,. ,. .*.’.- 4 6 6- ..- .-,,.. : .-.;.- -. NPS55-85-013 NAVAL POSTGRADUATE SCHOOL Monterey, California ESTIMATING THE PROBABILITY OF A DIFFUSING TARGET...PROBABILITY OF A DIFFUSING Technical TARGET ENCOUNTERING A STATIONARY SENSOR S. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(@) S. CONTRACT OR GRANT NUMBER(a

  12. An Investigation into the Nature of Non-Voiding Contractions Resulting from Detrusor Hyperreflexia in Neurogenic Bladders Following Spinal Cord Injury

    DTIC Science & Technology

    2014-10-01

    SCI) is often occasioned by numerous, rhythmic high pressure non-voiding contractions (NVC) during normal bladder filling. These NVC are...addition to the 16.5 month experiment period) 2c. Final data analysis (data analysis will be ongoing throughout, this will represent the finalization...accomplished. We accomplished Sub-Tasks 2a and 2b. As of 9/2/14, we have completed much of the data analysis (Sub-Task 2c; see below for results). Analysis

  13. Actions of cAMP on calcium sensitization in human detrusor smooth muscle contraction.

    PubMed

    Hayashi, Maya; Kajioka, Shunichi; Itsumi, Momoe; Takahashi, Ryosuke; Shahab, Nouval; Ishigami, Takao; Takeda, Masahiro; Masuda, Noriyuki; Yamaguchi, Akito; Naito, Seiji

    2016-01-01

    To clarify the effect of cAMP on the Ca(2+) -sensitized smooth muscle contraction in human detrusor, as well as the role of novel exchange protein directly activated by cAMP (Epac) in cAMP-mediated relaxation. All experimental protocols to record isometric tension force were performed using α-toxin-permeabilized human detrusor smooth muscle strips. The mechanisms of cAMP-mediated suppression of Ca(2+) sensitization activated by 10 μm carbachol (CCh) and 100 μm GTP were studied using a selective rho kinase (ROK) inhibitor, Y-27632, and a selective protein kinase C (PKC) inhibitor, GF-109203X. The relaxation mechanisms were further probed using a selective protein kinase A (PKA) activator, 6-Bnz-cAMP and a selective Epac activator, 8-pCPT-2'-O-Me-cAMP. We observed that CCh-induced Ca(2+) sensitization was inhibited by cAMP in a concentration-dependent manner. GF-109203X (10 μm) but not Y-27632 (10 μm) significantly enhanced the relaxation effect induced by cAMP (100 μm). 6-Bnz-cAMP (100 μm) predominantly decreased the tension force in comparison with 8-pCPT-2'-O-Me-cAMP (100 μm). We showed that cAMP predominantly inhibited the ROK pathway but not the PKC pathway. The PKA-dependent pathway is dominant, while Epac plays a minor role in human detrusor smooth muscle Ca(2+) sensitization. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  14. Squat-to-reach task in older and young adults: kinematic and electromyographic analyses.

    PubMed

    Kuo, Fang-Chuan; Kao, Wen-Pin; Chen, Hsiu-I; Hong, Chang-Zern

    2011-01-01

    The purpose of this study was to compare the two-dimensional kinematic and electromyographic (EMG) changes during the squat-to-reach task in older and young adults. Twenty-six older adults and thirty-three young adults were studied. A 16-channel telemetry system was used for recording muscular activity and kinematic data during two trials of a squat-to-reach task. Surface EMG data were recorded on select muscles of the trunk and the lower extremity on the dominant side. An electrogoniometer was fixed over the knee joint, and an inclinometer was fastened on the head and thigh to record kinematic data. The task was split into six movement phases based on the angular displacement and velocities of the knee joint. The mean values of the maximal displacements in the sagittal plane of the head, knee, and thigh were significantly (p<0.05) lower, but those in the frontal plane of the head and thigh were significantly (p<0.05) higher in older adults than in young adults. Thigh muscle activities were significantly (p<0.05) higher in older adults than in young adults throughout the movements. The trunk and leg muscles contracted earlier, but the hip adductors contracted later in older adults compared to young adults (p<0.05). The older adults squatted in a shallow and heel-off posture during forward reaching tasks. Therefore, older adults had increased lateral flexion of the head to compensate for insufficient knee flexion during the squat-to-reach movement and required increased activity of the posture muscles to maintain lateral stability. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Mice with a fra-1 knock-in into the c-fos locus show impaired spatial but regular contextual learning and normal LTP.

    PubMed

    Gass, Peter; Fleischmann, Alexander; Hvalby, Oivind; Jensen, Vidar; Zacher, Christiane; Strekalova, Tatyana; Kvello, Ane; Wagner, Erwin F; Sprengel, Rolf

    2004-11-04

    The immediate early gene c-fos is part of the AP-1 transcription factor complex, which is involved in molecular mechanisms underlying learning and memory. Mice that lack c-Fos in the brain show impairments in spatial reference and contextual learning, and also exhibit a reduced long-term potentiation of synaptic transmission (LTP) at CA3-to-CA1 synapses. In the present study, we investigated mice in which c-fos was deleted and replaced by fra-1 (c-fos(fra-1) mice) to determine whether other members of the c-fos gene family can substitute for the functions of the c-fos gene. In c-fos(fra-1) mice, both CA3-to-CA1 LTP and contextual learning in a Pavlovian fear conditioning task were similar to wild-type littermates, indicating that Fra-1 expression restored the impairments caused by brain-specific c-Fos depletion. However, c-Fos-mediated learning deficits in a reference memory task of the Morris watermaze were also present in c-fos(fra-1) mice. These findings suggest that different c-Fos target genes are involved in LTP, contextual learning, and spatial reference memory formation.

  16. Inactivation of avirulent Yersinia pestis on food and food contact surfaces by ultraviolet light and freezing.

    PubMed

    Sommers, Christopher H; Sheen, Shiowshuh

    2015-09-01

    Yersinia pestis, the causative agent of plague, can occasionally be contracted as a naso-pharyngeal or gastrointestinal illness through consumption of contaminated meat. In this study, the use of 254 nm ultraviolet light (UV-C) to inactivate a multi-isolate cocktail of avirulent Y. pestis on food and food contact surfaces was investigated. When a commercial UV-C conveyor was used (5 mW/cm(2)/s) 0.5 J/cm(2) inactivated >7 log of the Y. pestis cocktail on agar plates. At 0.5 J/cm(2), UV-C inactivated ca. 4 log of Y. pestis in beef, chicken, and catfish, exudates inoculated onto high density polypropylene or polyethylene, and stainless steel coupons, and >6 log was eliminated at 1 J/cm(2). Approximately 1 log was inactivated on chicken breast, beef steak, and catfish fillet surfaces at a UV-C dose of 1 J/cm(2). UV-C treatment prior to freezing of the foods did not increase the inactivation of Y. pestis over freezing alone. These results indicate that routine use of UV-C during food processing would provide workers and consumers some protection against Y. pestis. Published by Elsevier Ltd.

  17. Latent cardiac dysfunction as assessed by echocardiography in bed-bound patients following cerebrovascular accidents: comparison with nutritional status.

    PubMed

    Masugata, Hisashi; Senda, Shoichi; Goda, Fuminori; Yoshihara, Yumiko; Yoshikawa, Kay; Fujita, Norihiro; Himoto, Takashi; Okuyama, Hiroyuki; Taoka, Teruhisa; Imai, Masanobu; Kohno, Masakazu

    2007-07-01

    The aim of this study was to elucidate the cardiac function in bed-bound patients following cerebrovascular accidents. In accord with the criteria for activities of daily living (ADL) of the Japanese Ministry of Health, Labour and Welfare, 51 age-matched poststroke patients without heart disease were classified into 3 groups: rank A (house-bound) (n = 16, age, 85 +/- 6 years), rank B (chair-bound) (n = 16, age, 84 +/- 8 years), and rank C (bed-bound) (n = 19, age, 85 +/- 9 years). Using echocardiography, the left ventricular (LV) diastolic function was assessed by the ratio of early filling (E) and atrial contraction (A) transmitral flow velocities (E/A) of LV inflow. LV systolic function was assessed by LV ejection fraction (LVEF), and the Tei index was also measured to assess both LV systolic and diastolic function. No difference was observed in the E/A and LVEF among the 3 groups. The Tei index was higher in rank C (0.56 +/- 0.17) than in rank A (0.39 +/- 0.06) and rank B (0.48 +/- 0.17), and a statistically significant difference was observed between rank A and rank C (P < 0.05). Serum albumin and blood hemoglobin were significantly lower in rank C (3.1 +/- 0.4 and 10.6 +/- 1.8 g/dL) than in rank A (4.1 +/- 0.3 and 12.4 +/- 1.2 g/dL) (P < 0.001 and P < 0.05, respectively). These results indicate that latent cardiac dysfunction and poor nutritional status may exist in bed-bound patients (rank C) following cerebrovascular accidents. The Tei index may be a useful index of cardiac dysfunction in bed-bound patients because it is independent of the cardiac loading condition.

  18. 48 CFR 32.402 - General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... adequate security; (ii) The advance payments will not exceed the unpaid contract price (see 32.410(b... REQUIREMENTS CONTRACT FINANCING Advance Payments for Non-Commercial Items 32.402 General. (a) A limitation on authority to grant advance payments under Pub. L. 85-804 (50 U.S.C. 1431-1435) is described at 50.102-3(b)(4...

  19. Dielectric, Piezoelectric, and Vibration Properties of the LiF-Doped (Ba0.95Ca0.05)(Ti0.93Sn0.07)O₃ Lead-Free Piezoceramic Sheets.

    PubMed

    Cheng, Chien-Min; Chen, Kai-Huang; Lee, Da-Huei; Jong, Fuh-Cheng; Chen, Mei-Li; Chang, Jhih-Kai

    2018-01-24

    By the conventional solid state reaction method, a small amount of lithium fluoride (LiF) was used as the sintering promoter to improve the sintering and piezoelectric characteristics of (Ba 0.95 Ca 0.05 )(Ti 0.93 Sn 0.07 )O₃ (BCTS) lead-free piezoceramic sheets. Using X-ray diffraction (XRD) and a scanning electron microscope (SEM), the inferences of the crystalline and surface microstructures were obtained and analyzed. Then, the impedance analyzer and d 33 -meter were used to measure the dielectric and piezoelectric characteristics. In this study, the optimum sintering temperature of the BCTS sheets decreased from 1450 °C to 1390 °C due to LiF doping. For the 0.07 wt % LiF-doped BCTS sheets sintered at 1390 °C, the piezoelectric constant (d 33 ) is 413 pC/N, the electric-mechanical coupling coefficient (k p ) is 47.5%, the dielectric loss (tan δ) is 3.9%, and the dielectric constant (ε r ) is 8100, which are all close to or even better than that of the pure undoped BCTS ceramics. The Curie temperature also improved, from 85 °C for pure BCTS to 140 °C for BCTS-0.07 LiF sheets. Furthermore, by using the vibration system and fixing 1.5 g tip mass at the end of the sheets, as the vibration frequency is 20 Hz, the proposed piezoelectric ceramic sheets also reveal a good energy harvesting performance at the maximum output peak voltage of 4.6 V, which is large enough and can be applied in modern low-power electronic products.

  20. All Prime Contract Awards by State or Country, Place, and Contractor. Part 10 (Croom, Maryland-Mendon, Mass)

    DTIC Science & Technology

    1990-01-01

    A -IfCJ A ACI 11 LO n (O ? )-t ((D In ((D D-0- n InW ItJ0- W MJWW W .1 ..I<(-4 it I I 1-UCI 41) 0 (04 >1 :: o c" C c14 A CA ACCA C (,j AOCANAN" C CA C...7 )0470 C )) )4))M )( DD000 )0 )0 M0) 0) M0( F8 -00 0 0 8-481I8IM(0.4 it " 0) () r-000000000000000000000000000000000 00 0 ) ) -w I(0-4 it 1A

  1. Comparison of four statistical and machine learning methods for crash severity prediction.

    PubMed

    Iranitalab, Amirfarrokh; Khattak, Aemal

    2017-11-01

    Crash severity prediction models enable different agencies to predict the severity of a reported crash with unknown severity or the severity of crashes that may be expected to occur sometime in the future. This paper had three main objectives: comparison of the performance of four statistical and machine learning methods including Multinomial Logit (MNL), Nearest Neighbor Classification (NNC), Support Vector Machines (SVM) and Random Forests (RF), in predicting traffic crash severity; developing a crash costs-based approach for comparison of crash severity prediction methods; and investigating the effects of data clustering methods comprising K-means Clustering (KC) and Latent Class Clustering (LCC), on the performance of crash severity prediction models. The 2012-2015 reported crash data from Nebraska, United States was obtained and two-vehicle crashes were extracted as the analysis data. The dataset was split into training/estimation (2012-2014) and validation (2015) subsets. The four prediction methods were trained/estimated using the training/estimation dataset and the correct prediction rates for each crash severity level, overall correct prediction rate and a proposed crash costs-based accuracy measure were obtained for the validation dataset. The correct prediction rates and the proposed approach showed NNC had the best prediction performance in overall and in more severe crashes. RF and SVM had the next two sufficient performances and MNL was the weakest method. Data clustering did not affect the prediction results of SVM, but KC improved the prediction performance of MNL, NNC and RF, while LCC caused improvement in MNL and RF but weakened the performance of NNC. Overall correct prediction rate had almost the exact opposite results compared to the proposed approach, showing that neglecting the crash costs can lead to misjudgment in choosing the right prediction method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Mechanisms of neurokinin A- and substance P-induced contractions in rat detrusor smooth muscle in vitro.

    PubMed

    Quinn, Teresa; Collins, Colm; Baird, Alan W

    2004-09-01

    To investigate the mechanisms of neurokinin A- and substance P-induced contractions of rat urinary bladder smooth muscle, and to compare them with those of the muscarinic agonist carbachol. Rat urinary bladder strips were suspended under 1 g of tension in a physiological buffer at 37 degrees C, gassed with 95% O(2)/5% CO(2). Mechanical activity was recorded isometrically during exposure to neurokinin A and substance P. Both agents produced concentration-dependent contractions of smooth muscle strips which were unaffected by tetrodotoxin (1 micro mol/L), peptidase inhibitors (captopril, thiorphan and bestatin; 1 micro mol/L each) or piroxicam (10 micro mol/L). The rank order of potency of agonists was neurokinin A > substance P > carbachol. Contractile responses to neurokinin A and substance P, like the contractile responses to carbachol, were abolished in a nominally Ca(2+)-free medium and significantly reduced by nifedipine (1 micro mol/L). SKF-96365 (60 micro mol/L), an inhibitor of receptor-mediated Ca(2+) entry, abolished the nifedipine-resistant response to substance P and carbachol, and significantly attenuated the response to neurokinin A. Depleting intracellular Ca(2+) stores with thapsigargin (1 micro mol/L) significantly attenuated neurokinin A-induced contractions but had no effect on substance P- or carbachol- induced contractions. The Rho-kinase inhibitor, Y-27632 (10 micro mol/L), significantly reduced both phasic and tonic components of the contractile responses to neurokinin A, substance P and carbachol. The contractile responses induced by tachykinins in rat urinary bladder smooth muscle strips involve a direct action on smooth muscle and are not modulated by peptidases or prostanoids. Neurokinin A and substance P, like carbachol-induced contractions, depend on extracellular Ca(2+) influx largely through voltage-operated and partly through receptor-operated Ca(2+) channels. Intracellular Ca(2+) release contributes to the contractile response to neurokinin A but appears to have no involvement in substance P- and carbachol-induced contractions. Rho-kinase activation contributes to contractions induced by substance P, neurokinin A and carbachol.

  3. The other side of cardiac Ca2+ signaling: transcriptional control

    PubMed Central

    Domínguez-Rodríguez, Alejandro; Ruiz-Hurtado, Gema; Benitah, Jean-Pierre; Gómez, Ana M.

    2012-01-01

    Ca2+ is probably the most versatile signal transduction element used by all cell types. In the heart, it is essential to activate cellular contraction in each heartbeat. Nevertheless Ca2+ is not only a key element in excitation-contraction coupling (EC coupling), but it is also a pivotal second messenger in cardiac signal transduction, being able to control processes such as excitability, metabolism, and transcriptional regulation. Regarding the latter, Ca2+ activates Ca2+-dependent transcription factors by a process called excitation-transcription coupling (ET coupling). ET coupling is an integrated process by which the common signaling pathways that regulate EC coupling activate transcription factors. Although ET coupling has been extensively studied in neurons and other cell types, less is known in cardiac muscle. Some hints have been found in studies on the development of cardiac hypertrophy, where two Ca2+-dependent enzymes are key actors: Ca2+/Calmodulin kinase II (CaMKII) and phosphatase calcineurin, both of which are activated by the complex Ca2+/Calmodulin. The question now is how ET coupling occurs in cardiomyocytes, where intracellular Ca2+ is continuously oscillating. In this focused review, we will draw attention to location of Ca2+ signaling: intranuclear ([Ca2+]n) or cytoplasmic ([Ca2+]c), and the specific ionic channels involved in the activation of cardiac ET coupling. Specifically, we will highlight the role of the 1,4,5 inositol triphosphate receptors (IP3Rs) in the elevation of [Ca2+]n levels, which are important to locally activate CaMKII, and the role of transient receptor potential channels canonical (TRPCs) in [Ca2+]c, needed to activate calcineurin (Cn). PMID:23226134

  4. Fatigability and recovery of arm muscles with advanced age for dynamic and isometric contractions.

    PubMed

    Yoon, Tejin; Schlinder-Delap, Bonnie; Hunter, Sandra K

    2013-02-01

    This study determined whether age-related mechanisms can increase fatigue of arm muscles during maximal velocity dynamic contractions, as it occurs in the lower limb. We compared elbow flexor fatigue of young (n=10, 20.8±2.7 years) and old men (n=16, 73.8±6.1 years) during and in recovery from a dynamic and an isometric postural fatiguing task. Each task was maintained until failure while supporting a load equivalent to 20% of maximal voluntary isometric contraction (MVIC) torque. Transcranial magnetic stimulation (TMS) was used to assess supraspinal fatigue (superimposed twitch, SIT) and muscle relaxation. Time to failure was longer for the old men than for the young men for the isometric task (9.5±3.1 vs. 17.2±7.0 min, P=0.01) but similar for the dynamic task (6.3±2.4 min vs. 6.0±2.0 min, P=0.73). Initial peak rate of relaxation was slower for the old men than for the young men, and was associated with a longer time to failure for both tasks (P<0.05). Low initial power during elbow flexion was associated with the greatest difference (reduction) in time to failure between the isometric task and the dynamic task (r=-0.54, P=0.015). SIT declined after both fatigue tasks similarly with age, although the recovery of SIT was associated with MVIC recovery for the old (both sessions) but not for the young men. Biceps brachii and brachioradialis EMG activity (% MVIC) of the old men were greater than that of the young men during the dynamic fatiguing task (P<0.05), but were similar during the isometric task. Muscular mechanisms and greater relative muscle activity (EMG activity) explain the greater fatigue during the dynamic task for the old men compared with the young men in the elbow flexor muscles. Recovery of MVC torque however relies more on the recovery of supraspinal fatigue among the old men than among the young men. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Dynamic cerebral autoregulation during brain activation paradigms.

    PubMed

    Panerai, Ronney B; Moody, Michelle; Eames, Penelope J; Potter, John F

    2005-09-01

    Dynamic cerebral autoregulation (CA) describes the transient response of cerebral blood flow (CBF) to rapid changes in arterial blood pressure (ABP). We tested the hypothesis that the efficiency of dynamic CA is increased by brain activation paradigms designed to induce hemispheric lateralization. CBF velocity [CBFV; bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal Pco(2) were continuously recorded in 14 right-handed healthy subjects (21-43 yr of age), in the seated position, at rest and during 10 repeated presentations (30 s on-off) of a word generation test and a constructional puzzle. Nonstationarities were not found during rest or activation. Transfer function analysis of the ABP-CBFV (i.e., input-output) relation was performed for the 10 separate 51.2-s segments of data during activation and compared with baseline data. During activation, the coherence function below 0.05 Hz was significantly increased for the right MCA recordings for the puzzle tasks compared with baseline values (0.36 +/- 0.16 vs. 0.26 +/- 0.13, P < 0.05) and for the left MCA recordings for the word paradigm (0.48 +/- 0.23 vs. 0.29 +/- 0.16, P < 0.05). In the same frequency range, significant increases in gain were observed during the puzzle paradigm for the right (0.69 +/- 0.37 vs. 0.46 +/- 0.32 cm.s(-1).mmHg(-1), P < 0.05) and left (0.61 +/- 0.29 vs. 0.45 +/- 0.24 cm.s(-1).mmHg(-1), P < 0.05) hemispheres and during the word tasks for the left hemisphere (0.66 +/- 0.31 vs. 0.39 +/- 0.15 cm.s(-1).mmHg(-1), P < 0.01). Significant reductions in phase were observed during activation with the puzzle task for the right (-0.04 +/- 1.01 vs. 0.80 +/- 0.86 rad, P < 0.01) and left (0.11 +/- 0.81 vs. 0.57 +/- 0.51 rad, P < 0.05) hemispheres and with the word paradigm for the right hemisphere (0.05 +/- 0.87 vs. 0.64 +/- 0.59 rad, P < 0.05). Brain activation also led to changes in the temporal pattern of the CBFV step response. We conclude that transfer function analysis suggests important changes in dynamic CA during mental activation tasks.

  6. Sound Velocities of Iron-Nickel and Iron-Nickel-Silicon Alloys at High Pressure

    NASA Astrophysics Data System (ADS)

    Miller, R. A.; Jackson, J. M.; Sturhahn, W.; Zhao, J.; Murphy, C. A.

    2014-12-01

    Seismological and cosmochemical studies suggest Earth's core is primarily composed of iron with ~5 to 10 wt% nickel and some light elements [e.g. 1]. To date, the concentration of nickel and the amount and identity of light elements remain poorly constrained due in part to the difficulty of conducting experimental measurements at core conditions. The vibrational properties of a variety iron alloys paired with seismic observations can help better constrain the composition of the core. We directly measured the partial phonon density of states of bcc- and hcp-structured Fe0.9Ni0.1 and Fe0.85Ni0.1Si0.05 at high pressures. The samples were compressed using a panoramic diamond anvil cell. A subset of the experiments were conducted using neon as a pressure transmitting medium. Measurements of high statistical quality were performed with nuclear resonant inelastic x-ray scattering (NRIXS) at sector 3-ID-B of the Advanced Photon Source [2, 3, 4]. The unit cell volume of each sample was determined at each compression point with in-situ x-ray diffraction at sector 3-ID-B before and after each NRIXS measurement. The Debye, compressional, and shear sound velocities were determined from the low energy region of the partial phonon density of states paired with the volume measurements. We will present partial phonon density of states and sound velocities for Fe0.9Ni0.1 and Fe0.85Ni0.1Si0.05 at high-pressure and compare with those of pure iron. References: [1] McDonough, W.F. (2004): Compositional Model for the Earth's Core. Elsevier Ltd., Oxford. [2] Murphy, C.A., J.M. Jackson, W. Sturhahn, and B. Chen (2011): Melting and thermal pressure of hcp-Fe from the phonon density of states, Phys. Earth Planet. Int., doi:10.1016/j.pepi.2011.07.001. [3] Murphy, C.A., J.M. Jackson, W. Sturhahn, and B. Chen (2011): Grüneisen parameter of hcp-Fe to 171 GPa, Geophys. Res. Lett., doi:10.1029/2011GL049531. [4] Murphy, C.A., J.M. Jackson, and W. Sturhahn (2013): Experimental constraints on the thermodynamics and sound velocities of hcp-Fe to core pressures, J. Geophys. Res., doi:10.1002/jgrb.50166.

  7. Gender differences in the regulation of MLC20 phosphorylation and smooth muscle contraction in rat stomach

    PubMed Central

    Al-Shboul, Othman A.; Al-Dwairi, Ahmed N.; Alqudah, Mohammad A.; Mustafa, Ayman G.

    2018-01-01

    Evidence of sex-related differences in gastrointestinal (GI) functions has been reported in the literature. In addition, various GI disorders have disproportionate prevalence between the sexes. An essential step in the initiation of smooth muscle contraction is the phosphorylation of the 20-kDa regulatory myosin light chain (MLC20) by the Ca2+/calmodulin-dependent myosin light chain kinase (MLCK). However, whether male stomach smooth muscle inherits different contractile signaling mechanisms for the regulation of MLC20 phosphorylation from that in females has not been established. The present study was designed to investigate sex-associated differences in the regulation of MLC20 phosphorylation and thus muscle contraction in gastric smooth muscle cells (GSMCs). Experiments were performed on GSMCs freshly isolated from male and female rats. Contraction of the GSMCs in response to acetylcholine (ACh), a muscarinic agonist, was measured via scanning micrometry in the presence or absence of the MLCK inhibitor, ML-7. Additionally, the protein levels of MLC20, MLCK and phosphorylated MLC20 were measured by ELISA. The protein levels of MLC20 and MLCK were indifferent between the sexes. ACh induced greater contraction (P<0.05) as well as greater MLC20 phosphorylation (P<0.05) in male GSMCs compared with female. Pretreatment of GSMCs with ML-7 significantly reduced the ACh-induced contraction (P<0.05) and MLC20 phosphorylation (P<0.05) in the male and female cells, and notably, abolished the contractile differences between the sexes. In conclusion, MLC20 phosphorylation and thus muscle contraction may be activated to a greater extent in male rat stomach compared with that in females. PMID:29599980

  8. Deletion of the Mouse Homolog of CACNA1C Disrupts Discrete Forms of Hippocampal-Dependent Memory and Neurogenesis within the Dentate Gyrus.

    PubMed

    Temme, Stephanie J; Bell, Ryan Z; Fisher, Grace L; Murphy, Geoffrey G

    2016-01-01

    L-type voltage-gated calcium channels (LVGCCs) have been implicated in various forms of learning, memory, and synaptic plasticity. Within the hippocampus, the LVGCC subtype, Ca V 1.2 is prominently expressed throughout the dentate gyrus. Despite the apparent high levels of Ca V 1.2 expression in the dentate gyrus, the role of Ca V 1.2 in hippocampal- and dentate gyrus-associated forms of learning remain unknown. To address this question, we examined alternate forms of hippocampal-dependent associative and spatial memory in mice lacking the mouse ortholog of CACNA1C ( Cacna1c ), which encodes Ca V 1.2, with dentate gyrus function implicated in difficult forms of each task. We found that while the deletion of Ca V 1.2 did not impair the acquisition of fear of a conditioned context, mice lacking Ca V 1.2 exhibited deficits in the ability to discriminate between two contexts, one in which the mice were conditioned and one in which they were not. Similarly, Ca V 1.2 knock-out mice exhibited normal acquisition and recall of the location of the hidden platform in a standard Morris water maze, but were unable to form a memory of the platform location when the task was made more difficult by restricting the number of available spatial cues. Within the dentate gyrus, pan-neuronal deletion of Ca V 1.2 resulted in decreased cell proliferation and the numbers of doublecortin-positive adult-born neurons, implicating Ca V 1.2 in adult neurogenesis. These results suggest that Ca V 1.2 is important for dentate gyrus-associated tasks and may mediate these forms of learning via a role in adult neurogenesis and cell proliferation within the dentate gyrus.

  9. Caregiving for children with type 1 diabetes and clinical outcomes in central India: The IDREAM study.

    PubMed

    Friedemann-Sánchez, Greta; Capistrant, Benjamin D; Ron, James; Novak, Lindsey; Zuijdwijk, Caroline; Ogle, Graham D; Anderson, Barbara; Moran, Antoinette; Pendsey, Sharad

    2018-05-01

    Parental care influences outcomes for children's type 1 diabetes (T1D). There is little evidence about the impact of parental caregiving in developing countries, where fixed dose human insulin (conventional) therapy and limited self-monitoring of blood glucose are common. This article investigates whether performance of key T1D management tasks by children or their caregivers impacts hemoglobin A1c (HbA1c). We surveyed the caregivers of 179 children with T1D routinely treated in a specialized diabetes clinic in Maharashtra, India to determine who performs key diabetes care tasks: child or parent. We used linear regression to estimate the relationship between parental caregiving and HbA1c, and how this association varies by child age and time since diagnosis. Caregivers of older children were less involved in care tasks, though caregivers of 11- to 18-year olds performed more care for children diagnosed for a longer duration. Parental involvement in key insulin delivery tasks was associated with lower HbA1c levels for all children. These reductions were greatest among children 11 to 14 years old and diagnosed for less than 2 years: mean HbA1c levels were 8.5% (69 mmol/mol) if the caregiver, and 14.4% (134 mmol/mol) if the child, performed the tasks (P < .05). Parents of children diagnosed with T1D early in life remain involved in care throughout the child's adolescence. Parents of children diagnosed in late childhood and early adolescence are significantly less involved in care, and this is associated with worse glycemic control. Clinics must know who performs care tasks and tailor diabetes education appropriately. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Antispasmodic effect of Piper nigrum fruit hot water extract on rat ileum.

    PubMed

    Naseri, Mohammad Kazem Gharib; Yahyavi, Hoda

    2008-06-01

    The aim of this study was to investigate the effect of black pepper fruit hot water extract (BPE) on rat ileum contractility and the mechanism(s) of its action. The extract was prepared by adding black pepper powder to boiling distilled water followed by evaporated the solvent. Ileum was dissected from male adult rat (Wistar) and in Tyrode solution the tissue contractions were recorded by an isotonic transducer under 1 g tension. The cumulative concentrations of the BPE (0.0625-1 mg mL(-1)) reduced the ileum contractions induced by KCl (60 mM) or carbachol (10 microM) concentration dependently (p<0.001). In Ca2+-free Tyrode solution with high potassium (60 mM), BPE, (0.0625-1 mg mL(-1)) attenuated the contractions induced by cumulative concentrations of CaCl2 (0.225-2.7 mM) concentration dependently (ANOVA, p<0.05). The incubation of the tissue preparation (20 or 30 min) with L-NAME (100 microM), naloxone (1 microM) or propranolol (1 microM) did not reduce the extract antispasmodic effect on KCl-induced ileum contraction. The extract spasmolytic effect was attenuated neither by glibenclamide (10 microM) nor by tetraethylammonium (1 mM). Present results suggest that the spasmolytic effect of the extract on rat ileum was possibly mediated via Ca2+ influx.

  11. Summary document of tasks performed on the Shuttle-C/NLS contract

    NASA Technical Reports Server (NTRS)

    1993-01-01

    During FY92, USBI performed many programmatic related tasks. These programmatic tasks have been categorized as follows: (1) acquisition; (2) project engineering/program planning; and (3) cost. The reports associated with these tasks follow in paragraphs 1.1.1 through 1.3.3. Proceeding each task report is a brief description of the contents contained within.

  12. Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nobe, Koji, E-mail: kojinobe@pharm.showa-u.ac.jp; Nobe, Hiromi; Department of Physical Therapy, Bunkyo-Gakuin University

    Research highlights: {yields} Mechanisms of fibroblast cell contraction in collagen matrix. {yields} Assessed an isometric force development using 3D-reconstituted-fibroblast fiber. {yields} Constitutively active Rho A induced the over-contraction of fibroblast cells. {yields} Rho A and Rho kinase pathway has a central role in fibroblast cell contraction. -- Abstract: Fibroblast cells play a central role in the proliferation phase of wound healing processes, contributing to force development. The intracellular signaling pathways regulating this non-muscle contraction are only partially understood. To study the relations between Rho A and contractile responses, constitutively active Rho A (CA-Rho A) fibroblast cells were reconstituted into fibersmore » and the effects of calf serum (CS) on isometric force were studied. CS-induced force in CA-Rho A fibroblast fibers was twice as large as that in wild type (NIH 3T3) fibroblast fibers. During this response, the translocation of Rho A from the cytosol to the membrane was detected by Rho A activity assays and Western blot analysis. Pre-treatment with a Rho specific inhibitor (C3-exoenzyme) suppressed translocation as well as contraction. These results indicate that Rho A activation is essential for fibroblast contraction. The Rho kinase inhibitor ( (Y27632)) inhibited both NIH 3T3 and CA-Rho A fibroblast fiber contractions. Activation of Rho A is thus directly coupled with Rho kinase activity. We conclude that the translocation of Rho A from the cytosol to the membrane and the Rho kinase pathway can regulate wound healing processes mediated by fibroblast contraction.« less

  13. Mechanism of vasodilation induced by alpha-human atrial natriuretic polypeptide in rabbit and guinea-pig renal arteries.

    PubMed Central

    Fujii, K; Ishimatsu, T; Kuriyama, H

    1986-01-01

    Effects of alpha-human atrial natriuretic polypeptide (alpha-HANP) on electrical and mechanical properties of smooth muscle cells of the guinea-pig and rabbit renal arteries and of the guinea-pig mesenteric artery were investigated. alpha-HANP (up to 10 nM) modified neither the membrane potential nor resistance of smooth muscle cells of the guinea-pig and rabbit renal arteries. In the guinea-pig mesenteric and renal arteries, alpha-HANP (up to 10 nM) had no effect on the amplitude and facilitation (mesenteric artery) or depression (renal artery) of excitatory junction potentials nor on action potentials. In the guinea-pig renal artery, alpha-HANP (up to 10 nM) had no effect on the depolarization induced by noradrenaline (NA) (up to 10 microM) but markedly inhibited NA-induced contraction. alpha-HANP (10 nM) slightly inhibited the K-induced contraction. In the rabbit renal artery, alpha-HANP (10 nM) inhibited the NA-induced contraction and to a lesser extent the K-induced contraction. In the rabbit renal artery, the effects of alpha-HANP on the release of Ca from the cellular storage by two applications of NA, and its re-storage, were investigated in Ca-free solution containing 2 mM-EGTA. When 5 nM-alpha-HANP was applied before and during the first application of 0.5 microM-NA, the contraction was markedly inhibited but the contraction to a second application of 10 microM-NA was potentiated. If the first dose of NA was 10 microM the effect was very small. Under the same experimental procedures, nitroglycerine (10 microM) showed almost the same effects as alpha-HANP on the NA-induced contractions. When both the first (3 mM) and second (10 mM) contractions were evoked by caffeine in Ca-free solution, alpha-HANP (5 nM) and nitroglycerine (10 microM) inhibited both contractions to the same extent. In the rabbit renal artery, applications of alpha-HANP or nitroglycerine increased the amount of guanosine 3',5'-phosphate (cyclic GMP) in a dose-dependent manner. However, a much higher concentration of nitroglycerine was required (2 X 10(3) times). In the rabbit renal artery, hydrolysis of phosphatidyl inositol 4,5-bisphosphate (PI-P2) activated by 0.5 microM-NA was inhibited by alpha-HANP, in a dose-dependent manner, but activation by 10 microM-NA was not inhibited by alpha-HANP (up to 100 nM).(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3025429

  14. Stiffness and fraction of Myosin motors responsible for active force in permeabilized muscle fibers from rabbit psoas.

    PubMed

    Linari, Marco; Caremani, Marco; Piperio, Claudia; Brandt, Philip; Lombardi, Vincenzo

    2007-04-01

    The stiffness of the single myosin motor (epsilon) is determined in skinned fibers from rabbit psoas muscle by both mechanical and thermodynamic approaches. Changes in the elastic strain of the half-sarcomere (hs) are measured by fast mechanics both in rigor, when all myosin heads are attached, and during active contraction, with the isometric force (T0) modulated by changing either [Ca2+] or temperature. The hs compliance is 43.0+/-0.8 nm MPa-1 in isometric contraction at saturating [Ca2+], whereas in rigor it is 28.2+/-1.1 nm MPa-1. The equivalent compliance of myofilaments is 21.0+/-3.3 nm MPa-1. Accordingly, the stiffness of the ensemble of myosin heads attached in the hs is 45.5+/-1.7 kPa nm-1 in isometric contraction at saturating [Ca2+] (e0), and in rigor (er) it rises to 138.9+/-21.2 kPa nm-1. Epsilon, calculated from er and the lattice molecular dimensions, is 1.21+/-0.18 pN nm-1. epsilon estimated, using a thermodynamic approach, from the relation of T0 at saturating [Ca2+] versus the reciprocal of absolute temperature is 1.25+/-0.14 pN nm-1, similar to that estimated for fibers in rigor. Consequently, the ratio e0/er (0.33+/-0.05) can be used to estimate the fraction of attached heads during isometric contraction at saturating [Ca2+]. If the osmotic agent dextran T-500 (4 g/100 ml) is used to reduce the lateral filament spacing of the relaxed fiber to the value before skinning, both e0 and er increase by approximately 40%. Epsilon becomes approximately 1.7 pN nm-1 and the fraction and the force of myosin heads attached in the isometric contraction remain the same as before dextran application. The finding that the fraction of myosin heads attached to actin in an isometric contraction is 0.33 rules out the hypothesis of multiple mechanical cycles per ATP hydrolyzed.

  15. Synthesis and characterization of high-Tc superconductors in the Tl-Ca-Ba-Cu-O system

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Farrell, D. E.

    1989-01-01

    Both Tl2Ca2Ba2Cu3O10 and TlCa3BaCu3O8.5 are investigated for superconductivity as a function of the sintering temperature, time, atmosphere, and quench rate in an effort to synthesize the high-Tc superconducting phase in the thallium system. The samples are characterized by electrical resistivity measurements, X-ray diffraction, and scanning electron microscopy. Samples of starting composition Tl2Ca2Ba2Cu3O10 fired in air at 860-900 C and rapidly quenched show a Tc of 96-107 K. In contrast, specimens of starting composition TlCa3BaCu3O8.5 when baked at 900 C and slowly cooled in oxygen superconduct at 116 K and above and consist of Tl2Ca2Ba2Cu3O(10+x) as the dominant phase. The results also show that, in contrast to the case of YBa2Cu3O(7-x), doping with a small concentration of fluorine sharpens the resistive transition and produces a large Tc increase in thallium-based superconductors.

  16. 22. Historic American Buildings Survey Runnels & Stateler, Photographers c. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Historic American Buildings Survey Runnels & Stateler, Photographers c. 1882 - 85 Collection of Senator Edward F. Burton REFINERY - U. S. Branch Mint, Mission & Fifth Streets, San Francisco, San Francisco County, CA

  17. Spasmolytic effect of citral and extracts of Cymbopogon citratus on isolated rabbit ileum.

    PubMed

    Devi, Ramachandran Chitra; Sim, Si Mui; Ismail, Rosnah

    2011-01-01

    Cymbopogon citratus, commonly known as lemongrass, has been shown to have antioxidant, antimicrobial and chemo-protective properties. Citral, a monoterpenoid, is the major constituent of C. citratus that gives off a lemony scent and is postulated to be responsible for most of its actions. In addition, C. citratus has been traditionally used to treat gastrointestinal discomforts, however, the scientific evidence for this is still lacking. Thus, the aim of the present study was to investigate the effect of the extracts of various parts of C. citratus (leaves, stems and roots) and citral on the visceral smooth muscle activity of rabbit ileum. The effect of the test substances were tested on the spontaneous contraction, acetylcholine (ACh)- and KCl-induced contractions. Citral at doses between 0.061 mM to 15.6 mM and the extract of leaves at doses between 0.001 mg/mL to 1 mg/mL significantly reduced the spontaneous, ACh- and KCl-induced ileal contractions. When the ileum was incubated in K(+)-rich-Ca(2+)-free Tyrode's solution, it showed only minute contractions. However, the strength of contraction was increased with the addition of increasing concentrations of CaCl(2). The presence of citral almost abolished the effect of adding CaCl(2), while the leaf extract shifted the calcium concentration-response curve to the right, suggesting a calcium antagonistic effect. These results were similar to that elicited by verapamil, a known calcium channel blocker. In addition, the spasmolytic effect of citral was observed to be reduced by the nitric oxide synthase inhibitor, L-NAME. In conclusion, citral and the leaf extract of C. citratus exhibited spasmolytic activity and it appeared that they may act as calcium antagonists. Furthermore, the relaxant effect of citral, but not that of the leaf extract may be mediated by nitric oxide suggesting the presence of other chemical components in the leaf extract other than citral.

  18. 78 FR 33392 - Public Availability of Consumer Product Safety Commission FY 2012 Service Contract Inventory

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... made through a contract or task order; (B) The organizational component of the executive agency administering the contract, and the organizational component of the agency whose requirements are being met through contractor performance of the service; (C) The total dollar amount obligated for services under...

  19. Effect of hypnotic suggestion on knee extensor neuromuscular properties in resting and fatigued states

    PubMed Central

    Antonini Philippe, Roberta; Guglielmo, Luiz Guilherme A.

    2018-01-01

    Purpose The aim of this study was to investigate whether hypnotic suggestions can alter knee extensor neuromuscular function at rest and during exercise. Methods Thirteen healthy volunteers (8 men and 5 women, 27 ± 3 years old) took part in this counterbalanced, crossover study including two experimental (hypnosis and control) sessions. Knee extensor neuromuscular function was tested before and after hypnosis suggestion by using a combination of voluntary contraction, transcutaneous femoral nerve electrical stimulation and transcranial magnetic stimulation (TMS). A fatiguing exercise (sustained submaximal contraction at 20% maximal voluntary contraction (MVC) force) was also performed to evaluate the potential influence of hypnosis on the extent and origin of neuromuscular adjustments. Results Hypnosis did not (p>0.05) alter MVC force or knee extensor neural properties. Corticospinal excitability, assessed with the amplitude of knee extensor motor evoked potentials, was also unchanged (p>0.05), as was the level of intracortical inhibition assessed with paired pulse TMS (short-interval intracortical inhibition, SICI). Time to task failure (~300 s) was not different (p>0.05) between the two sessions; accordingly, hypnosis did not influence neuromuscular adjustments measured during exercise and at task failure (p>0.05). Conclusion Hypnotic suggestions did not alter neuromuscular properties of the knee extensor muscles under resting condition or during/after exercise, suggesting that hypnosis-induced improvement in exercise performance and enhanced corticospinal excitability might be limited to highly susceptible participants. PMID:29684047

  20. Evaluation of the Consolidation of Real Property Maintenance Activities (RPMA) in the U.S. Army Engineer Activity, Capital Area (USAEA, CA). Volume 2. Evaluation

    DTIC Science & Technology

    1990-03-01

    MANAGEMENT ................................... 62 Scope of Current Operations 62 Evolution of the Original RMD Plan 66 Financial Management Support Operations...Scope of Current Operations 76 Evolution of SMD From IPG Plan 78 SMD Support to RPMA 81 Efficiency of Supply Service 85 7 PROCUREMENT AND CONTRACTING...RPMA are to be realized. This chapter investigates these controls in terms of scope, evolution , operations (a functional assessment), and efficiency

  1. Mississippi CaP HBCU Undergraduate Research Training Program

    DTIC Science & Technology

    2017-11-01

    AWARD NUMBER: W81XWH-14-1-0151 TITLE: Mississippi CaP HBCU Undergraduate Research Training Program PRINCIPAL INVESTIGATOR: Christian Gomez...Final PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT: Approved for...2017 4. TITLE AND SUBTITLE Mississippi CaP HBCU Undergraduate Research Training Program 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0151 5c

  2. ESTCP Live Site Demonstrations Former Camp Beale, Marysville, CA

    DTIC Science & Technology

    2011-08-23

    ESTCP Live Site Demonstrations Former Camp Beale Marysville, CA ESTCP MR-201165 Demonstration Data Report Former Camp Beale...with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE AUG 2011 2 . REPORT TYPE N/A 3. DATES...COVERED - 4. TITLE AND SUBTITLE ESTCP Live Site Demonstrations Former Camp Beale Marysville, CA 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  3. Microstructure, mechanical properties and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy processed at various finish rolling temperatures

    NASA Astrophysics Data System (ADS)

    Kang, Qiang; Jiang, Haitao; Zhang, Yun

    2018-04-01

    Effects of various finish rolling temperatures on the microstructure, texture, mechanical properties and stretch formability of rolled and annealed Mg-3Al-0.5Ca-0.2Gd (wt%) alloy were investigated in this paper, and it was found that compared with grain size and second phase particles, the basal textures, tensile properties and stretch formability Mg-3Al-0.5Ca-0.2Gd alloy are more sensitive to the increasing finishing rolling temperature. For the rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy, their grains barely grow up and second phase particles are slightly coarsened, while their basal poles are obviously weakened and tilted with increasing finish rolling temperature. Consequently, the weakened and RD-tilted basal textures are beneficial to the gradually improved elongation and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy. It is investigated that the gradually activated non-basal slips, e. g. 〈c 〉, 〈c + a〉 dislocations due to the increasing finish rolling temperature could contribute to the weakened RD-tilted textures in rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy.

  4. Human muscle economy myoblast differentiation and excitation-contraction coupling use the same molecular partners, STIM1 and STIM2.

    PubMed

    Darbellay, Basile; Arnaudeau, Serge; Ceroni, Dimitri; Bader, Charles R; Konig, Stephane; Bernheim, Laurent

    2010-07-16

    Our recent work identified store-operated Ca(2+) entry (SOCE) as the critical Ca(2+) source required for the induction of human myoblast differentiation (Darbellay, B., Arnaudeau, S., König, S., Jousset, H., Bader, C., Demaurex, N., and Bernheim, L. (2009) J. Biol. Chem. 284, 5370-5380). The present work indicates that STIM2 silencing, similar to STIM1 silencing, reduces myoblast SOCE amplitude and differentiation. Because myoblasts in culture can be induced to differentiate into myotubes, which spontaneously contract in culture, we used the same molecular tools to explore whether the Ca(2+) mechanism of excitation-contraction coupling also relies on STIM1 and STIM2. Live cell imaging of early differentiating myoblasts revealed a characteristic clustering of activated STIM1 and STIM2 during the first few hours of differentiation. Thapsigargin-induced depletion of endoplasmic reticulum Ca(2+) content caused STIM1 and STIM2 redistribution into clusters, and co-localization of both STIM proteins. Interaction of STIM1 and STIM2 was revealed by a rapid increase in fluorescence resonance energy transfer between CFP-STIM1 and YFP-STIM2 after SOCE activation and confirmed by co-immunoprecipitation of endogenous STIM1 and STIM2. Although both STIM proteins clearly contribute to SOCE and are required during the differentiation process, STIM1 and STIM2 are functionally largely redundant as overexpression of either STIM1 or STIM2 corrected most of the impact of STIM2 or STIM1 silencing on SOCE and differentiation. With respect to excitation-contraction, we observed that human myotubes rely also on STIM1 and STIM2 to refill their endoplasmic reticulum Ca(2+)-content during repeated KCl-induced Ca(2+) releases. This indicates that STIM2 is a necessary partner of STIM1 for excitation-contraction coupling. Thus, both STIM proteins are required and interact to control SOCE during human myoblast differentiation and human myotube excitation-contraction coupling.

  5. Human Muscle Economy Myoblast Differentiation and Excitation-Contraction Coupling Use the Same Molecular Partners, STIM1 and STIM2*

    PubMed Central

    Darbellay, Basile; Arnaudeau, Serge; Ceroni, Dimitri; Bader, Charles R.; Konig, Stephane; Bernheim, Laurent

    2010-01-01

    Our recent work identified store-operated Ca2+ entry (SOCE) as the critical Ca2+ source required for the induction of human myoblast differentiation (Darbellay, B., Arnaudeau, S., König, S., Jousset, H., Bader, C., Demaurex, N., and Bernheim, L. (2009) J. Biol. Chem. 284, 5370–5380). The present work indicates that STIM2 silencing, similar to STIM1 silencing, reduces myoblast SOCE amplitude and differentiation. Because myoblasts in culture can be induced to differentiate into myotubes, which spontaneously contract in culture, we used the same molecular tools to explore whether the Ca2+ mechanism of excitation-contraction coupling also relies on STIM1 and STIM2. Live cell imaging of early differentiating myoblasts revealed a characteristic clustering of activated STIM1 and STIM2 during the first few hours of differentiation. Thapsigargin-induced depletion of endoplasmic reticulum Ca2+ content caused STIM1 and STIM2 redistribution into clusters, and co-localization of both STIM proteins. Interaction of STIM1 and STIM2 was revealed by a rapid increase in fluorescence resonance energy transfer between CFP-STIM1 and YFP-STIM2 after SOCE activation and confirmed by co-immunoprecipitation of endogenous STIM1 and STIM2. Although both STIM proteins clearly contribute to SOCE and are required during the differentiation process, STIM1 and STIM2 are functionally largely redundant as overexpression of either STIM1 or STIM2 corrected most of the impact of STIM2 or STIM1 silencing on SOCE and differentiation. With respect to excitation-contraction, we observed that human myotubes rely also on STIM1 and STIM2 to refill their endoplasmic reticulum Ca2+-content during repeated KCl-induced Ca2+ releases. This indicates that STIM2 is a necessary partner of STIM1 for excitation-contraction coupling. Thus, both STIM proteins are required and interact to control SOCE during human myoblast differentiation and human myotube excitation-contraction coupling. PMID:20436167

  6. Coupling of Rigor Mortis and Intestinal Necrosis during C. elegans Organismal Death.

    PubMed

    Galimov, Evgeniy R; Pryor, Rosina E; Poole, Sarah E; Benedetto, Alexandre; Pincus, Zachary; Gems, David

    2018-03-06

    Organismal death is a process of systemic collapse whose mechanisms are less well understood than those of cell death. We previously reported that death in C. elegans is accompanied by a calcium-propagated wave of intestinal necrosis, marked by a wave of blue autofluorescence (death fluorescence). Here, we describe another feature of organismal death, a wave of body wall muscle contraction, or death contraction (DC). This phenomenon is accompanied by a wave of intramuscular Ca 2+ release and, subsequently, of intestinal necrosis. Correlation of directions of the DC and intestinal necrosis waves implies coupling of these death processes. Long-lived insulin/IGF-1-signaling mutants show reduced DC and delayed intestinal necrosis, suggesting possible resistance to organismal death. DC resembles mammalian rigor mortis, a postmortem necrosis-related process in which Ca 2+ influx promotes muscle hyper-contraction. In contrast to mammals, DC is an early rather than a late event in C. elegans organismal death. VIDEO ABSTRACT. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  7. Dietary calcium intake and renin angiotensin system polymorphisms alter the blood pressure response to aerobic exercise: a randomized control design.

    PubMed

    Pescatello, Linda S; Turner, Debbie; Rodriguez, Nancy; Blanchard, Bruce E; Tsongalis, Gregory J; Maresh, Carl M; Duffy, Valerie; Thompson, Paul D

    2007-01-04

    Dietary calcium intake and the renin angiotensin system (RAS) regulate blood pressure (BP) by modulating calcium homeostasis. Despite similar BP regulatory effects, the influence of dietary calcium intake alone and combined with RAS polymorphisms on the BP response following acute aerobic exercise (i.e., postexercise hypotension) has not been studied. Thus, we examined the effect of dietary calcium intake and selected RAS polymorphisms on postexercise hypotension. Subjects were men (n = 50, 43.8 +/- 1.3 yr) with high BP (145.3 +/- 1.5/85.9 +/- 1.1 mm Hg). They completed three experiments: non-exercise control and two cycle bouts at 40% and 60% of maximal oxygen consumption (VO2max). Subjects provided 3 d food records on five protocol-specific occasions. Dietary calcium intake was averaged and categorized as low (<880 mg/d = LowCa) or high (> or = 880 mg/d = HighCa). RAS polymorphisms (angiotensin converting enzyme insertion/deletion, ACE I/D; angiotensin II type 1 receptor, AT1R A/C) were analyzed with molecular methods. Genotypes were reduced from three to two: ACE II/ID and ACE DD; or AT1R AA and AT1R CC/AC. Repeated measure ANCOVA tested if BP differed among experiments, dietary calcium intake level and RAS polymorphisms. Systolic BP (SBP) decreased 6 mm Hg after 40% and 60% VO2max compared to non-exercise control for 10 h with LowCa (p < 0.01), but not with HighCa (p > or = 0.05). Under these conditions, diastolic BP (DBP) did not differ between dietary calcium intake levels (p > or = 0.05). With LowCa, SBP decreased after 60% VO2max versus non-exercise control for 10 h among ACE II/ID (6 mm Hg) and AT1R AA (8 mm Hg); and by 8 mm Hg after 40% VO2max among ACE DD and AT1R CC/CA (p < 0.01). With HighCa, SBP (8 mm Hg) and DBP (4 mm Hg) decreased after 60% VO2max compared to non-exercise control for 10 h (p < 0.05), but not after 40% VO2max (p > or = 0.05). SBP decreased after exercise compared to non-exercise control among men with low but not high dietary calcium intake. Dietary calcium intake interacted with the ACE I/D and AT1R A/C polymorphisms to further modulate postexercise hypotension. Interactions among dietary calcium intake, exercise intensity and RAS polymorphisms account for some of the variability in the BP response to exercise.

  8. The repeated-bout effect: influence on biceps brachii oxygenation and myoelectrical activity.

    PubMed

    Muthalib, Makii; Lee, Hoseong; Millet, Guillaume Y; Ferrari, Marco; Nosaka, Kazunori

    2011-05-01

    This study investigated biceps brachii oxygenation and myoelectrical activity during and following maximal eccentric exercise to better understand the repeated-bout effect. Ten men performed two bouts of eccentric exercise (ECC1, ECC2), consisting of 10 sets of 6 maximal lengthening contractions of the elbow flexors separated by 4 wk. Tissue oxygenation index minimum amplitude (TOI(min)), mean and maximum total hemoglobin volume by near-infrared spectroscopy, torque, and surface electromyography root mean square (EMG(RMS)) during exercise were compared between ECC1 and ECC2. Changes in maximal voluntary isometric contraction (MVC) torque, range of motion, plasma creatine kinase activity, muscle soreness, TOI(min), and EMG(RMS) during sustained (10-s) and 30-repeated isometric contraction tasks at 30% (same absolute force) and 100% MVC (same relative force) for 4 days postexercise were compared between ECC1 and ECC2. No significant differences between ECC1 and ECC2 were evident for changes in torque, TOI(min), mean total hemoglobin volume, maximum total hemoglobin volume, and EMG(RMS) during exercise. Smaller (P < 0.05) changes and faster recovery of muscle damage markers were evident following ECC2 than ECC1. During 30% MVC tasks, TOI(min) did not change, but EMG(RMS) increased 1-4 days following ECC1 and ECC2. During 100% MVC tasks, EMG(RMS) did not change, but torque and TOI(min) decreased 1-4 days following ECC1 and ECC2. TOI(min) during 100% MVC tasks and EMG(RMS) during 30% MVC tasks recovered faster (P < 0.05) following ECC2 than ECC1. We conclude that the repeated-bout effect cannot be explained by altered muscle activation or metabolic/hemodynamic changes, and the faster recovery in muscle oxygenation and activation was mainly due to faster recovery of force.

  9. Enabling computer decisions based on EEG input.

    PubMed

    Culpepper, Benjamin J; Keller, Robert M

    2003-12-01

    Multilayer neural networks were successfully trained to classify segments of 12-channel electroencephalogram (EEG) data into one of five classes corresponding to five cognitive tasks performed by a subject. Independent component analysis (ICA) was used to segregate obvious artifact EEG components from other sources, and a frequency-band representation was used to represent the sources computed by ICA. Examples of results include an 85% accuracy rate on differentiation between two tasks, using a segment of EEG only 0.05 s long and a 95% accuracy rate using a 0.5-s-long segment.

  10. Enabling computer decisions based on EEG input

    NASA Technical Reports Server (NTRS)

    Culpepper, Benjamin J.; Keller, Robert M.

    2003-01-01

    Multilayer neural networks were successfully trained to classify segments of 12-channel electroencephalogram (EEG) data into one of five classes corresponding to five cognitive tasks performed by a subject. Independent component analysis (ICA) was used to segregate obvious artifact EEG components from other sources, and a frequency-band representation was used to represent the sources computed by ICA. Examples of results include an 85% accuracy rate on differentiation between two tasks, using a segment of EEG only 0.05 s long and a 95% accuracy rate using a 0.5-s-long segment.

  11. Fatigue and recovery from dynamic contractions in men and women differ for arm and leg muscles.

    PubMed

    Senefeld, Jonathon; Yoon, Tejin; Bement, Marie Hoeger; Hunter, Sandra K

    2013-09-01

    Whether there is a gender difference in fatigue and recovery from maximal velocity fatiguing contractions and across muscles is not understood. Sixteen men and 19 women performed 90 isotonic contractions at maximal voluntary shortening velocity (maximal velocity concentric contractions, MVCC) with the elbow flexor and knee extensor muscles (separate days) at a load equivalent to 20% maximal voluntary isometric contraction (MVIC). Power (from MVCCs) decreased similarly for men and women for both muscles (P > 0.05). Men and women had similar declines in MVIC of elbow flexors, but men had greater reductions in knee extensor MVIC force and MVIC electromyogram activity than women (P < 0.05). The decline in MVIC and power was greater, and force recovery was slower for the elbow flexors compared with knee extensors. The gender difference in muscle fatigue often observed during isometric tasks was diminished during fast dynamic contractions for upper and lower limb muscles. Copyright © Published 2013 by Wiley Periodicals, Inc. This article is a US Government wmusork and, as such, is in the public domain in the United States of America.

  12. In Vivo Perturbation of Membrane-Associated Calcium by Freeze-Thaw Stress in Onion Bulb Cells 1

    PubMed Central

    Arora, Rajeev; Palta, Jiwan P.

    1988-01-01

    Incipient freeze-thaw stress in onion bulb scale tissue is known to cause enhanced efflux of K+, along with small but significant loss of cellular Ca2+. During the post-thaw period, irreversibly injured cells undergo a cytological aberration, namely, `protoplasmic swelling.' This cellular symptom is thought to be caused by replacement of Ca2+ from membrane by extracellular K+ and subsequent perturbation of K+ transport properties of plasma membrane. In the present study, onion (Allium cepa L. cv Sweet Sandwich) bulbs were slowly frozen to either −8.5°C or −11.5°C and thawed over ice. Inner epidermal peels from bulb scales were treated with fluorescein diacetate for assessing viability. In these cells, membrane-associated calcium was determined using chlorotetracycline fluorescence microscopy combined with image analysis. Increased freezing stress and tissue infiltration (visual water-soaking) were paralleled by increased ion leakage. Freezing injury (−11.5°C; irreversible) caused a specific and substantial loss of membrane-associated Ca2+ compared to control. Loss of membrane-associated Ca2+ caused by moderate stress (−8.5°C; reversible) was much less relative to −11.5°C treatment. Ion efflux and Ca2+-chlorotetracycline fluorescence showed a negative relationship. Extracellular KCl treatment simulated freeze-thaw stress by causing a similar loss of membrane-associated calcium. This loss was dramatically reduced by presence of extracellular CaCl2. Our results suggest that the loss of membrane-associated Ca2+, in part, plays a role in initiation and progression of freezing injury. Images Fig. 1 Fig. 2 PMID:16666196

  13. 20. San FranciscoOakland Bay Bridge contract recipients, April 28, 1933, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. San Francisco-Oakland Bay Bridge contract recipients, April 28, 1933, photographer unknown. Standing, left to right: Edward J. Schneider, Columbia Steel Corporation; C.C. Horton, Healy-Tibbitts Construction Company; Henry J. Kaiser, Bridge Builders, Inc.; Albert Huber, Clinton Construction Company; Allan McDonald, Transbay Construction Company; C.C. Carleton, Chief, Division of Contracts and Rights of Way, California Department of Public Works. Seated, left to right: Henry J. Brunnier, Consulting Engineer, Member of Consulting Board, San Francisco-Oakland Bay Bridge; Charles E. Andrew, Bridge Engineer, San Francisco-Oakland Bay Bridge; Earl Lee Kelly, Director, California Department of Public Works; Harrison S. Robinson, President, Financial ... - Salt River Bridge, Spanning Salt River at Dillon Road, Ferndale, Humboldt County, CA

  14. Inhibitory effects of HgCl2 on excitation-secretion coupling at the motor nerve terminal and excitation-contraction coupling in the muscle cell.

    PubMed

    Røed, A; Herlofson, B B

    1994-12-01

    1. Indirect and direct twitch (0.1-Hz) stimulation of the rat phrenic nerve-diaphragm disclosed that the inhibitory effect of HgCl2, 3.7 x 10(-5) M, on the neuromuscular transmission and in the muscle cell, was accelerated by 10-sec periods of 50-Hz tetanic stimulation every 10 min. This activity-dependent enhancement suggested an inhibitory mechanism of HgCl2 related to the development of fatigue, like membrane depolarization or decreased excitability, decreased availability of transmitter, or interference with the factors controlling excitation-secretion coupling of the nerve terminal, i.e. (Ca2+)0 or (Ca2+)i, and excitation-contraction coupling in the muscle cell, i.e., (Ca2+)i. 2. During both indirect and direct stimulation, HgCl2-induced inhibition was enhanced markedly by pretreatment with caffeine, which releases Ca2+ from endoplasmic and sarcoplasmic reticulum in the nerve terminal and muscle cell, respectively. This caffeine-induced enhancement was completely antagonized by dantrolene, which inhibits the caffeine-induced release. However, dantrolene alone did not antagonize the HgCl2-induced inhibition. 3. Since caffeine depletes the intracellular Ca2+ stores of the smooth endoplasmic reticulum, HgCl2 probably inhibits by binding to SH groups of transport proteins conveying the messenger function of (Ca2+)i. In the muscle cell this leads to inhibition of contraction. In the nerve terminal, an additional enhancement of the HgCl2-induced inhibition, by inhibiting reuptake of choline by TEA and tetanic stimulation, suggested that HgCl2 inhibited a (Ca2+)i signal necessary for this limiting factor in resynthesis of acetylcholine. 4. The (Ca2+)0 signal necessary for stimulus-induced release of acetylcholine was not affected by HgCl2. Hyperpolarization in K(+)-free solution antagonized the inhibitory effect of HgCl2 at indirect stimulation, and Ca(2+)-free solution enhanced the inhibitory effect at direct stimulation. K+ depolarization, membrane electric field increase with high Ca2+, membrane stabilization with lidocaine, and half-threshold stimulation, did not change the inhibitory effect of HgCl CH3HgCl. 1.85 x 10(-5) M, disclosed a synergistic interaction with caffeine during direct, but not during indirect, stimulation.

  15. Contraction produced by intracellular injection of calcium, strontium, and barium in the single crayfish muscle fibers.

    PubMed

    Matsumura, M; Mashima, H

    1976-01-01

    Ca ions were ionophoretically injected through an intracellular microelectrode into the single muscle fiber of a crayfish, and the resulting contraction sphere was observed under a microscope and photographed with a movie camera. The minimum contraction produced by the threshold current involved usually three or four, sometimes two, sarcomers on both sides of the injecting pipette but contraction involving only one sarcomere was not observered. The rheobase of the Ca-injecting current was 3.2 X 10(-9) A. The strength-duration curves were determined for Ca-, Sr-, and Ba-injecting currents; all fitted a similar hyperbolic equation. The threshold amount of Ca above rheobasic injection was 2.1 X 10(-15)mol, and the ratios between threshold amounts were Ca: Sr: Ba=1: 1.9: 3.0. The effects of Ca and Sr were additive for the contraction. More current was required for the Ca-injection to produce the contraction in the K-depolarized-or 15mM-procaine-treated muscle, although less current was sufficient for the muscle treated with 0.5-1.0 mM of caffeine. The participation of the Ca-induced Ca release mechanism in the contraction produced by Ca injection and the role of Sr or Ba as a substitute for Ca were discussed.

  16. Relaxation of isolated guinea-pig trachea by apigenin, a constituent of celery, via inhibition of phosphodiesterase.

    PubMed

    Chen, Junn-Lain; Ko, Wun-Chang

    2017-09-15

    Apigenin, was reported to have vasodilatory effects by inhibiting Ca 2+ influx through both voltage- and receptor-operated calcium channels, but not by inhibiting cAMP- or cGMP-phosphodiesterases (PDEs) in rat thoracic aorta. However, apigenin was reported to inhibit PDE1, 2 and 3 in guinea-pig lung and heart. The aim of this study was to clarify that guinea-pig tracheal relaxation by apigenin whether via PDE inhibition. We isometrically recorded the tension of isolated guinea-pig tracheal segments on a polygraph. Antagonistic effects of apigenin against cumulative contractile agents or Ca 2+ induced contractions of the trachealis in normal or isotonic high-K + , Ca 2+ -free Krebs solution, respectively. Effects of apigenin (15 and 30μM) on the cumulative forskolin- and nitroprusside-induced relaxations to histamine (30μM)-induced precontraction were performed. The inhibitory effects of 30-300μM apigenin and 3-isobutyl-1-methylxanthine (IBMX, positive control) on the cAMP- and cGMP-PDEs were determined. Apigenin concentration-dependently but non-competitively inhibited cumulative histamine-, carbachol- or Ca 2+ -induced contractions in normal or in the depolarized (K + , 60mM) trachealis, suggesting that Ca 2+ influx through voltage-dependent calcium channels is inhibited. However, apigenin (15-30μM) parallel leftward shifted the concentration-response curves of forskolin and nitroprusside, and significantly increased the pD 2 values of these two cyclase activators. Both apigenin and IBMX, a reference drug, concentration (10-300μM)-dependently and significantly, but non-selectively inhibited the activities of cAMP- and cGMP-PDEs in the trachealis. In conclusion, the relaxant effect of apigenin may be due to inhibition of both enzyme activities and reduction of intracellular Ca 2+ by inhibiting Ca 2+ influx in the trachealis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Increased Ca2+ sensitivity of contractile elements via protein kinase C in alpha-toxin permeabilized SMA from young spontaneously hypertensive rats.

    PubMed

    Sasajima, H; Shima, H; Toyoda, Y; Kimura, K; Yoshikawa, A; Hano, T; Nishio, I

    1997-10-01

    The purpose of the present investigation was to examine the Ca2+ sensitivity of the contractile elements via protein kinase C (PKC) in superior mesenteric artery (SMA) from young (5-6 weeks old) spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Staphylococcal aureus alpha-toxin, which produces pores in the plasma membrane too small to allow passage of proteins such as PKC, was used to investigate the signal transduction system in vascular smooth muscle cells. We investigated the Ca2+ sensitivity of the contractile apparatus via PKC in intact and alpha-toxin skinned SMA from young SHR and WKY. In intact SMA, high K+ responses were not different between SHR and WKY. However, phorbol 12,13-dibutyrate (PDBu, a PKC activator) augmented high K(+)-evoked contractions and PKC inhibitors, such as 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) and calphostin C, suppressed them more in SHR as compared with WKY. In alpha-toxin skinned SMA, the [Ca2+]i-force relationship curve was not significantly different between SHR and WKY. However, PDBu augmented [Ca2+]i-evoked contractions and PKC inhibitors suppressed them more in SHR than in WKY. These results suggest that the Ca2+ sensitivity of the contractile elements via PKC is significantly greater in prehypertensive SHR than in age-matched WKY. This abnormality in small muscular arteries may be involved in the pathogenesis of hypertension in SHR.

  18. Task- and time-dependent modulation of Ia presynaptic inhibition during fatiguing contractions performed by humans

    PubMed Central

    Maerz, Adam H.; Gould, Jeffrey R.; Enoka, Roger M.

    2011-01-01

    Presynaptic modulation of Ia afferents converging onto the motor neuron pool of the extensor carpi radialis (ECR) was compared during contractions (20% of maximal force) sustained to failure as subjects controlled either the angular position of the wrist while supporting an inertial load (position task) or exerted an equivalent force against a rigid restraint (force task). Test Hoffmann (H) reflexes were evoked in the ECR by stimulating the radial nerve above the elbow. Conditioned H reflexes were obtained by stimulating either the median nerve above the elbow or at the wrist (palmar branch) to assess presynaptic inhibition of homonymous (D1 inhibition) and heteronymous Ia afferents (heteronymous Ia facilitation), respectively. The position task was briefer than the force task (P = 0.001), although the maximal voluntary force and electromyograph for ECR declined similarly at failure for both tasks. Changes in the amplitude of the conditioned H reflex were positively correlated between the two conditioning methods (P = 0.02) and differed between the two tasks (P < 0.05). The amplitude of the conditioned H reflex during the position task first increased (129 ± 20.5% of the initial value, P < 0.001) before returning to its initial value (P = 0.22), whereas it increased progressively during the force task to reach 122 ± 17.4% of the initial value at failure (P < 0.001). Moreover, changes in conditioned H reflexes were associated with the time to task failure and force fluctuations. The results suggest a task- and time-dependent modulation of presynaptic inhibition of Ia afferents during fatiguing contractions. PMID:21543747

  19. Mechanisms underlying the reduced endothelium-dependent relaxation in human omental resistance artery in pre-eclampsia

    PubMed Central

    Suzuki, Yoshikatsu; Kajikuri, Junko; Suzumori, Kaoru; Itoh, Takeo

    2000-01-01

    In pre-eclampsia, a functional change occurs in the role played by endothelium-derived nitric oxide (NO) in the regulation of smooth muscle contraction in resistance arteries. We investigated the underlying mechanism in human omental resistance arteries from normotensive pregnant and pre-eclamptic women in the presence of diclofenac (an inhibitor of cyclo-oxygenase).In endothelium-intact strips, the sensitivity to 9,11-epithio-11,12-methano-thromboxane A2 (STA2) was significantly higher in pre-eclampsia, and this was not modified by either NG-nitro-l-arginine (l-NNA, an inhibitor of NO synthase) or removal of the endothelium.Bradykinin and substance P each produced an endothelium-dependent relaxation of the STA2-induced contraction in both groups, although the relaxation was significantly smaller for pre-eclampsia. l-NNA markedly attenuated the endothelium-dependent relaxation in the normotensive pregnant group but not in the pre-eclamptic group.In the presence of l-NNA, the relaxation induced by sodium nitroprusside (SNP) on the STA2 contraction was significantly smaller for pre-eclamptic than for normotensive pregnant women.In endothelium-denuded strips, the relaxation induced by 8-para- chlorophenyl thio-guanosine-3′,5′-cyclic monophosphate (8-pCPT-cGMP) on the STA2 contraction was significantly less for pre-eclampsia.In β-escin-skinned strips from both groups of women, 8-pCPT-cGMP (1–10 μm) concentration-dependently attenuated the contraction induced by 0.5 μm Ca2+. However, its relaxing action was significantly weaker in pre-eclampsia.It is suggested that the weaker responsiveness to NO seen in strips from pre-eclamptic women may be partly due to a reduced smooth muscle responsiveness to cyclic GMP. PMID:10944179

  20. Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

    PubMed

    Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

    2018-02-22

    Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. All Prime Contract Awards by State or Country, Place, and Contractor, FY83, Part 5 (LaGrange, Indiana-Escanaba, Michigan).

    DTIC Science & Technology

    1983-01-01

    N00104-83-CA014 B C A 1 2 2 1361 000 AS DEPTH CHARGE EXPLOSIVE COMPO 8 A 3 4 J 018 1 B J 1 J 174 2 E JA116 4000 N00104-83-CA014 B C A 1 2 2 1386 000 A6... EXPLOSIVE ORD DISPOSAL TOOL- 8 A 6 4 J 018 1 B J 1 E 84 2 A JA116 1398 N00104-63-CA026 B C A 1 3 2 1361 000 AS DEPTH CHARGE EXPLOSIVE COMPO 8 A 3 4 J...CA088 B C A 1 2 2 1356 000 AS TORPEDO EXPLOSIVE COMPONENTS 8 A 3 5 A 1001 5 B J 1 H 195 2 G PAIOt A700 N00140-83-CBA83 B C Z 1 2 2 R414 000 51 MOT

  2. Multifunctional PSCA antibody fragments for PET and optical prostate cancer imaging

    DTIC Science & Technology

    2017-10-01

    INVESTIGATOR: Anna M. Wu CONTRACTING ORGANIZATION: University of California, Los Angeles Los Angeles, CA 90095-1406 REPORT DATE : October 2017 TYPE OF...cys- minibodies and cys-diabodies) can be labeled with radioisotopes for non-invasive PET imaging for use at multiple points in the prostate cancer...optimize and test multifunctional, F-18, and alternatively labeled fragments Major Task 3. New technologies: alternative site-specific labeling methods

  3. Blood Biomarker Profile of TBI Associated Cognitive Impairment Among Old and Young Veterans

    DTIC Science & Technology

    2016-10-01

    INVESTIGATOR: Kristine Yaffe, MD CONTRACTING ORGANIZATION: Northern California Institute for Research and Education San Francisco, CA 94121 REPORT...MD 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Northern California Institute for Research and Education ...and Resiliency for Dementia: Comparison of Male and Female Veterans (Yaffe: PI) Time Commitment: 1.2 calendar months Supporting Agency: DOD

  4. 78 FR 53809 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing and Immediate Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... (Rule 1009A(f)), U.S. Dollar-Settled Foreign Currency option contracts (Rule 1057) and PHLX FOREX option... 1037, 1042(c) and (h), 1057, 1006A, 1009A(f), 1042A(b), 1101A(c), Rule 1101A, Commentary .01, 1006C(a...

  5. Clinical Investigation Program RCS MED-300 (R1).

    DTIC Science & Technology

    1985-09-30

    of Group A Streptococcus ......................................... 193 Work Unit No. 85/17 (FY85,T) Serological Survey of Epstein - Barr Virus ...Prot No: 85/17 Status: Terminated Title: Serological Survey of Epstein - Barr Virus Infections Followed Over a 12-Month Period Start Date: Est Comp Date...Principal Investigator: Facility: CPT C.A. Borchert, MC Dept/Sec: Pediatrics Assoc Investigators Key Words: Epstein - Barr Virus Accumulative MEDCASE Est

  6. Distinct cognitive control mechanisms as revealed by modality-specific conflict adaptation effects.

    PubMed

    Yang, Guochun; Nan, Weizhi; Zheng, Ya; Wu, Haiyan; Li, Qi; Liu, Xun

    2017-04-01

    Cognitive control is essential to resolve conflict in stimulus-response compatibility (SRC) tasks. The SRC effect in the current trial is reduced after an incongruent trial as compared with a congruent trial, a phenomenon being termed conflict adaptation (CA). The CA effect is found to be domain-specific , such that it occurs when adjacent trials contain the same type of conflict, but disappears when the conflicts are of different types. Similar patterns have been observed when tasks involve different modalities, but the modality-specific effect may have been confounded by task switching. In the current study, we investigated whether or not cognitive control could transfer across auditory and visual conflicts when task-switching was controlled. Participants were asked to respond to a visual or auditory (Experiments 1A/B) stimulus, with conflict coming from either the same or a different modality. CA effects showed modality-specific patterns. To account for potential confounding effects caused by differences in task-irrelevant properties, we specifically examined the influence of task-irrelevant properties on CA effects within the visual modality (Experiments 2A/B). Significant CA effects were observed across different conflicts from distinct task-irrelevant properties, ruling out that the lack of cross-modal CA effects in Experiments 1A/B resulted from differences in task-irrelevant information. Task-irrelevant properties were further matched in Experiments 3A/B to examine the pure effect of modality. Results replicated Experiments 1A/B showing robust modality-specific CA effects. Taken together, we provide supporting evidences that modality affects cognitive control in conflict resolution, which should be taken into account in theories of cognitive control. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. K2P TASK-2 and KCNQ1-KCNE3 K+ channels are major players contributing to intestinal anion and fluid secretion.

    PubMed

    Julio-Kalajzić, Francisca; Villanueva, Sandra; Burgos, Johanna; Ojeda, Margarita; Cid, L Pablo; Jentsch, Thomas J; Sepúlveda, Francisco V

    2018-02-01

    K + channels are important in intestinal epithelium as they ensure the ionic homeostasis and electrical potential of epithelial cells during anion and fluid secretion. Intestinal epithelium cAMP-activated anion secretion depends on the activity of the (also cAMP dependent) KCNQ1-KCNE3 K + channel, but the secretory process survives after genetic inactivation of the K + channel in the mouse. Here we use double mutant mice to investigate which alternative K + channels come into action to compensate for the absence of KCNQ1-KCNE3 K + channels. Our data establish that whilst Ca 2+ -activated K Ca 3.1 channels are not involved, K 2P two-pore domain TASK-2 K + channels are major players providing an alternative conductance to sustain the intestinal secretory process. Work with double mutant mice lacking both TASK-2 and KCNQ1-KCNE3 channels nevertheless points to yet-unidentified K + channels that contribute to the robustness of the cAMP-activated anion secretion process. Anion and fluid secretion across the intestinal epithelium, a process altered in cystic fibrosis and secretory diarrhoea, is mediated by cAMP-activated CFTR Cl - channels and requires the simultaneous activity of basolateral K + channels to maintain cellular ionic homeostasis and membrane potential. This function is fulfilled by the cAMP-activated K + channel formed by the association of pore-forming KCNQ1 with its obligatory KCNE3 β-subunit. Studies using mice show sizeable cAMP-activated intestinal anion secretion in the absence of either KCNQ1 or KCNE3 suggesting that an alternative K + conductance must compensate for the loss of KCNQ1-KCNE3 activity. We used double mutant mouse and pharmacological approaches to identify such a conductance. Ca 2+ -dependent anion secretion can also be supported by Ca 2+ -dependent K Ca 3.1 channels after independent CFTR activation, but cAMP-dependent anion secretion is not further decreased in the combined absence of K Ca 3.1 and KCNQ1-KCNE3 K + channel activity. We show that the K 2P K + channel TASK-2 is expressed in the epithelium of the small and large intestine. Tetrapentylammonium, a TASK-2 inhibitor, abolishes anion secretory current remaining in the absence of KCNQ1-KCNE3 activity. A double mutant mouse lacking both KCNQ1-KCNE3 and TASK-2 showed a much reduced cAMP-mediated anion secretion compared to that observed in the single KCNQ1-KCNE3 deficient mouse. We conclude that KCNQ1-KCNE3 and TASK-2 play major roles in the intestinal anion and fluid secretory phenotype. The persistence of an, admittedly reduced, secretory activity in the absence of these two conductances suggests that further additional K + channel(s) as yet unidentified contribute to the robustness of the intestinal anion secretory process. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  8. Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p- chlorobenzenesulfonylamino)-butyl]-azulene-1-sulfonic acid sodium salt); a new TXA2/prostaglandin endoperoxide receptor antagonist.

    PubMed

    Kosakai, K; Wakabayashi, S; Sato, T; Mochizuki, S; Tomiyama, A; Zhou, Q; Satake, N; Shibata, S

    1993-03-01

    Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p-chlorobenzenesulfonylamino)butyl]-azulene+ ++-1-sulfonic acid sodium salt, KT) were studied in isolated rat aorta, rat tail artery, rabbit aorta, rabbit renal artery, and pig coronary artery. KT competitively inhibited the contractions induced by thromboxane A2 (TXA2) mimetic, U46619 (pA2 values 9.95, 8.85, 7.87, 8.49, and 9.12, respectively). KT also inhibited the contraction of rabbit aorta induced by prostaglandin2 alpha (PGF2 alpha, pA2 value 7.85) and the contraction of guinea pig ileum induced by LTD4 (pA2 value 5.48) but did not alter the contractions induced by norepinephrine (NE), Ca2+, serotonin, and histamine. KT did not alter the contractions of guinea pig ileum, which did not contract with U46619, induced by PGE2 and PGF2 alpha. KT inhibited the aggregations of rabbit platelets induced by U46619, arachidonic acid, and collagen (IC50 values 7.9, 140, and 16 microM, respectively) but not those induced by ADP. It also inhibited the specific binding of TXA2/PGH2 receptor antagonist, [3H]SQ29,548, to rabbit gel-filtered platelets with an IC50 value of 1.5 x 10(-8) M. In in vivo experiments with mice, oral administration of KT protected the U46619-induced sudden death with the minimum effective dose of 0.3 mg/kg and provided such protection for > 8 h at 1.0 mg/kg. These results indicate that KT is a new nonprostanoid type TXA2/PGH2 receptor antagonist that is orally effective and long acting.

  9. Vasorelaxant effects of Brillantaisia nitens Lindau (Acanthaceae) extracts on isolated rat vascular smooth muscle.

    PubMed

    Dimo, T; Mtopi, O-S Bopda; Nguelefack, T B; Kamtchouing, P; Zapfack, L; Asongalem, E A; Dongo, E

    2007-04-20

    Brillantaisia nitens Lindau (Acanthaceae) is traditionally used in Cameroon for the treatment of many diseases including cardiovascular disorders. We have studied its vasorelaxant effects in rat vascular smooth muscle. In this study, aqueous, methylene chloride, methanol, and methylene chloride/methanol leaves extracts of Brillantaisia nitens were tested for their relaxing ability in vitro. Strips of rat aorta, with or without intact endothelium, were mounted in tissue baths, contracted with KCl (60mM) or norepinephrine (10(-4)M), and then exposed to the plant extracts. These extracts exhibited concentration-dependent vasorelaxations of norepinephrine-induced contractions of intact aortic strips. The EC(50) were 0.42+/-0.01mg/ml (aqueous extract), 0.63+/-0.02mg/ml (methylene chloride extract), 0.73+/-0.02mg/ml (methanol extract) and 0.36+/-0.02mg/ml (methylene chloride/methanol extract). The methylene chloride/methanol (CH(2)Cl(2)/CH(3)OH) extract was the most potent relaxing extract. It caused a concentration-dependent and endothelium-independent relaxation of the rat aortic strips contracted by KCl or norepinephrine. On the NE-induced contraction, its maximal relaxant activity (109%) due to the dose of 1.5mg/ml, was not significantly modified by the pretreatment of aortic strips with indomethacin (89%, P>0.05) or with l-NAME (103%, P>0.05). This suggests that the vasorelaxation elicited by CH(2)Cl(2)/CH(3)OH extract was not mediated via endothelium-derived prostacyclin or nitric oxide. In contrast, this relaxation was markedly reduced by tetraethylammonium, a blocker of non-selective K(+) channels and glibenclamide, a blocker of ATP-sensitive K(+) channels. The CH(2)Cl(2)/CH(3)OH extract significantly inhibited Ca(2+)-induced concentration-contraction and the Ca(2+) influx in aortic strips incubated with 60mM KCl. These results indicate that the vasorelaxant effect of the CH(2)Cl(2)/CH(3)OH extract of Brillantaisia nitens is due to an inhibition of Ca(2+) influx, possibly via the activation of ATP-sensitive K(+) channels.

  10. [Soy isoflavones with supplemental calcium provide protection against the loss of bone mass and influence insulin-like growth factor (IGF)-I after ovariectomy in rat].

    PubMed

    Cheng, Mao-wei; Liu, Jia-fa; Yi, Guo-qin; Zhang, Xi-ping; Zhu, Qing-hua; Liu, Lie-gang

    2006-09-01

    To compare the effects of soy isoflavone with supplemental calcium to soy isoflavone or Ca alone on preservation of bone mineral density (BMD) and the expression of insulin-like growth factor (IGF)-I. Sprague-Dawley (SD) female Rats, 6 months old, were ovariectomized and randomized into five groups: sham-operated group (n = 10) or ovx (n = 40) group. Shams were fed a 3.272 g/kg Ca diet. Ovx rats were randomized to a 3.272 g/kg Ca diet alone (OVX) or with soy isoflavone (SI) extract (37.95 mg/kg.bw) or to a supplemental Ca diet (Ca, 4.676 g/kg) alone or a supplemental Ca diet with the isoflavone extract (SI + Ca) for 12 weeks. BMD of femur was measured by scanner of bone mineral density. The level of IGF-1 mRNA expression was measured by reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. There was no significant difference between group Sham (0.267 +/- 0.008) and group SI + Ca (0.263 +/- 0.007) g/cm(2) (P > 0.05) on femur BMD of distal end. Femur BMD of distal end in group Sham and group SI + Ca was greater (P < 0.05) as compared to group OVX (0.245 +/- 0.005) g/cm(2), SI (0.258 +/- 0.011) g/cm(2) or Ca (0.255 +/- 0.004) g/cm(2), P < 0.05. The liver tissue IGF-1 mRNA contents (IGF-1 cDNA/B-actin cDNA) were significantly decreased in group Sham (0.200 +/- 0.023) g/cm(2), SI (0.278 +/- 0.019) g/cm(2), Ca (0.302 +/- 0.026) g/cm(2) or SI + Ca (0.231 +/- 0.025) g/cm(2) as compared to group OVX (0.362 +/- 0.031) g/cm(2), P < 0.05; The liver tissue IGF-1 mRNA contents (IGF-1 cDNA/B-actin cDNA) were significantly decreased in group SI + Ca (0.231 +/- 0.025) g/cm(2) compared to group SI (0.278 +/- 0.019) g/cm(2) and Ca (0.302 +/- 0.026) g/cm(2), P < 0.05. Soy isoflavones combined with supplemental Ca are more protective against the loss of femur BMD than soy isoflavones or supplemental Ca diet alone. The dose of SI (37.95 mg/kg.bw) might significantly restrain the rising of the liver tissue IGF-1 mRNA contents caused by ovariectomy.

  11. Role of innate immunity and altered intestinal motility in LPS- and MnCl2-induced intestinal intussusception in mice

    PubMed Central

    Killoran, Kristin E.; Miller, Amber D.; Uray, Karen S.; Weisbrodt, Norman W.; Pautler, Robia G.; Goyert, Sanna M.; van Rooijen, Nico

    2014-01-01

    Intestinal intussusception (ISS) commonly causes intestinal obstruction in children. One mechanism that has been proposed to cause ISS is inflammation-induced alteration of intestinal motility. We investigated whether innate inflammatory factors or altered motility is required for induction of ISS by LPS. We compared rates of ISS among BALB/c and C57BL/6 mice, mice lacking lymphocytes or depleted of phagocytes, or mice with defects in the Toll-like receptor 4 (TLR4) signaling pathway following administration of LPS or the Ca2+ analog MnCl2. At 6 or 2 h after administration of LPS or MnCl2, respectively, mice underwent image analysis to assess intestinal contraction rate or laparotomy to identify ISS. LPS-induced ISS (LPS-ISS) was observed in BALB/c mice, but not in C57BL/6 mice or any BALB/c mice with disruptions of TLR4 signaling. LPS-induced serum TNF-α, IL-6, and nitric oxide (NO) and intestinal NO levels were similar in BALB/c and C57BL/6 mice. The rate of LPS-ISS was significantly reduced in phagocyte-depleted, but not lymphocyte-deficient, mice. Intestinal contraction rates were reduced in LPS-ISS-susceptible BALB/c mice, but not in LPS-ISS-resistant C57BL/6 or TLR4 mutant mice, suggesting a role for reduced intestinal contraction rate in LPS-ISS susceptibility. This was tested with MnCl2, a Ca2+ antagonist that reduced intestinal contraction rates and induced ISS, irrespective of mouse strain. Therefore, LPS-ISS is initiated by innate immune signaling that requires TLR4 and phagocytes but may be independent of TNF-α, IL-6, and NO levels. Furthermore, alteration of intestinal motility, specifically, reduced intestinal contraction rate, is a key factor in the development of ISS. PMID:24407593

  12. PC-PLC/sphingomyelin synthase activity plays a central role in the development of myogenic tone in murine resistance arteries

    PubMed Central

    Zacharia, Joseph; Fairfax, Seth; Wier, Withrow Gil

    2015-01-01

    Myogenic tone is an intrinsic property of the vasculature that contributes to blood pressure control and tissue perfusion. Earlier investigations assigned a key role in myogenic tone to phospholipase C (PLC) and its products, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). Here, we used the PLC inhibitor, U-73122, and two other, specific inhibitors of PLC subtypes (PI-PLC and PC-PLC) to delineate the role of PLC in myogenic tone of pressurized murine mesenteric arteries. U-73122 inhibited depolarization-induced contractions (high external K+ concentration), thus confirming reports of nonspecific actions of U-73122 and its limited utility for studies of myogenic tone. Edelfosine, a specific inhibitor of PI-PLC, did not affect depolarization-induced contractions but modulated myogenic tone. Because PI-PLC produces IP3, we investigated the effect of blocking IP3 receptor-mediated Ca2+ release on myogenic tone. Incubation of arteries with xestospongin C did not affect tone, consistent with the virtual absence of Ca2+ waves in arteries with myogenic tone. D-609, an inhibitor of PC-PLC and sphingomyelin synthase, strongly inhibited myogenic tone and had no effect on depolarization-induced contraction. D-609 appeared to act by lowering cytoplasmic Ca2+ concentration to levels below those that activate contraction. Importantly, incubation of pressurized arteries with a membrane-permeable analog of DAG induced vasoconstriction. The results therefore mandate a reexamination of the signaling pathways activated by the Bayliss mechanism. Our results suggest that PI-PLC and IP3 are not required in maintaining myogenic tone, but DAG, produced by PC-PLC and/or SM synthase, is likely through multiple mechanisms to increase Ca2+ entry and promote vasoconstriction. PMID:25888510

  13. Positive inotropism in mammalian skeletal muscle in vitro during and after fatigue.

    PubMed

    Reading, S A; Murrant, C L; Barclay, J K

    2004-04-01

    We tested the hypothesis that positive inotropic factors decrease fatigue and improve recovery from fatigue in mammalian skeletal muscle in vitro. To induce fatigue, we stimulated mouse soleus and extensor digitorum longus (EDL) to perform isometric tetanic contractions (50 impulses x s(-1) for 0.5 s) at 6 contractions x min(-1) for 60 min in soleus and 3 contractions x min(-1) for 20 min in EDL. Muscles were submerged in Krebs-Henseleit bicarbonate solution (Krebs) at 27 degrees C gassed with 95% nitrogen - 5% carbon dioxide (anoxia). Before and for 67 min after the fatigue period, muscles contracted at 0.6 contractions x min(-1) in 95% oxygen - 5% carbon dioxide (hyperoxia). We added a permeable cAMP analog (N6, 2'-O-dibutyryladenosine 3':5'-cyclic monophosphate at 10(-3) mol x L(-1) (dcAMP)), caffeine (2 x 10(-3) mol x L(-1), or Krebs as vehicle control at 25 min before, during, or at the end of the fatigue period. In soleus and EDL, both challenges added before fatigue significantly increased developed force but only caffeine increased developed force when added during the fatigue period. At the end of fatigue, the decrease in force in challenged muscles was equal to or greater than in controls so that the force remaining was the same or less than in controls. EDL challenged with dcAMP or caffeine at any time recovered more force than controls. In soleus, caffeine improved recovery except when added before fatigue. With dcAMP added to soleus, recovery was better after challenges at 10 min and the end of the fatigue period. Thus, increased intracellular concentrations of cAMP and (or) Ca2+ did not decrease fatigue in either muscle but improved recovery from fatigue in EDL and, in some conditions, in soleus.

  14. Extracellular acidosis selectively inhibits pharmacomechanical coupling induced by carbachol in strips of rat gastric fundus.

    PubMed

    de Oliveira, Daniel Maia Nogueira; Batista-Lima, Francisco José; de Carvalho, Emanuella Feitosa; Havt, Alexandre; da Silva, Moisés Tolentino Bento; Dos Santos, Armênio Aguiar; Magalhães, Pedro Jorge Caldas

    2017-12-01

    What is the central question of this study? Acute acidosis that results from short-term exercise is involved in delayed gastric emptying in rats and the lower responsiveness of gastric fundus strips to carbachol. Does extracellular acidosis decrease responsiveness to carbachol in tissues of sedentary rats? How? What is the main finding and its importance? Extracellular acidosis inhibits cholinergic signalling in the rat gastric fundus by selectively influencing the G q/11 protein signalling pathway. Acute acidosis that results from short-term exercise delays gastric emptying in rats and decreases the responsiveness to carbachol in gastric fundus strips. The regulation of cytosolic Ca 2+ concentrations appears to be a mechanism of action of acidosis. The present study investigated the way in which acidosis interferes with gastric smooth muscle contractions. Rat gastric fundus isolated strips at pH 6.0 presented a lower magnitude of carbachol-induced contractions compared with preparations at pH 7.4. This lower magnitude was absent in carbachol-stimulated duodenum and KCl-stimulated gastric fundus strips. In Ca 2+ -free conditions, repeated contractions that were induced by carbachol progressively decreased, with no influence of extracellular pH. In fundus strips, CaCl 2 -induced contractions were lower at pH 6.0 than at pH 7.4 but only when stimulated in the combined presence of carbachol and verapamil. In contrast, verapamil-sensitive contractions that were induced by CaCl 2 in the presence of KCl did not change with pH acidification. In Ca 2+ store-depleted preparations that were treated with thapsigargin, the contractions that were induced by extracellular Ca 2+ restoration were smaller at pH 6.0 than at pH 7.4, but relaxation that was induced by SKF-96365 (an inhibitor of store-operated Ca 2+ entry) was unaltered by extracellular acidification. At pH 6.0, the phospholipase C inhibitor U-73122 relaxed carbachol-induced contractions less than at pH 7.4, and this phenomenon was absent in tissue that was treated with the RhoA kinase blocker Y-27632. Thus, extracellular acidosis inhibited pharmacomechanical coupling in gastric fundus by selectively inhibiting the G q/11 protein signalling pathway, whereas electromechanical coupling remained functionally preserved. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

  15. Striatal D1- and D2-type dopamine receptors are linked to motor response inhibition in human subjects.

    PubMed

    Robertson, Chelsea L; Ishibashi, Kenji; Mandelkern, Mark A; Brown, Amira K; Ghahremani, Dara G; Sabb, Fred; Bilder, Robert; Cannon, Tyrone; Borg, Jacqueline; London, Edythe D

    2015-04-15

    Motor response inhibition is mediated by neural circuits involving dopaminergic transmission; however, the relative contributions of dopaminergic signaling via D1- and D2-type receptors are unclear. Although evidence supports dissociable contributions of D1- and D2-type receptors to response inhibition in rats and associations of D2-type receptors to response inhibition in humans, the relationship between D1-type receptors and response inhibition has not been evaluated in humans. Here, we tested whether individual differences in striatal D1- and D2-type receptors are related to response inhibition in human subjects, possibly in opposing ways. Thirty-one volunteers participated. Response inhibition was indexed by stop-signal reaction time on the stop-signal task and commission errors on the continuous performance task, and tested for association with striatal D1- and D2-type receptor availability [binding potential referred to nondisplaceable uptake (BPND)], measured using positron emission tomography with [(11)C]NNC-112 and [(18)F]fallypride, respectively. Stop-signal reaction time was negatively correlated with D1- and D2-type BPND in whole striatum, with significant relationships involving the dorsal striatum, but not the ventral striatum, and no significant correlations involving the continuous performance task. The results indicate that dopamine D1- and D2-type receptors are associated with response inhibition, and identify the dorsal striatum as an important locus of dopaminergic control in stopping. Moreover, the similar contribution of both receptor subtypes suggests the importance of a relative balance between phasic and tonic dopaminergic activity subserved by D1- and D2-type receptors, respectively, in support of response inhibition. The results also suggest that the stop-signal task and the continuous performance task use different neurochemical mechanisms subserving motor response inhibition. Copyright © 2015 the authors 0270-6474/15/355990-08$15.00/0.

  16. Effect of heat–moisture treatment on digestibility of different cultivars of sweet potato (Ipomea batatas (L.) Lam) starch

    PubMed Central

    Senanayake, Suraji; Gunaratne, Anil; Ranaweera, K K D S; Bamunuarachchi, Arthur

    2014-01-01

    Different heat–moisture levels were applied to native starches from different cultivars of sweet potatoes available in Sri Lanka (Wariyapola red, Wariyapola white, Pallepola variety, Malaysian variety and CARI 273) to study the digestibility level. Samples were treated with 20, 25, and 30% moisture at 85°C and 120°C for 6 h and in vitro starch digestibility was tested with porcine pancreatin enzyme. A range of 19.3–23.5% digestibility was shown by the native starches with no significant difference (P < 0.05). Significant changes were observed in the digestibility level of the hydrothermally modified starches and the moisture content showed a positive impact on the digestibility. Heat–moisture treatment at 85°C brought an overall increase in digestibility and temperature beyond 85°C had a negative impact. No significant difference (P < 0.05) in the digestibility was observed with 20% and 25% moisture at 85°C and increased level were seen at 85°C and 30% moisture. PMID:25473497

  17. Use of autochthonous starters to ferment red and yellow peppers (Capsicum annum L.) to be stored at room temperature.

    PubMed

    Di Cagno, Raffaella; Surico, Rosalinda F; Minervini, Giovanna; De Angelis, Maria; Rizzello, Carlo G; Gobbetti, Marco

    2009-03-31

    Strains of Lactobacillus curvatus, Leuconostoc mesenteroides, Lactobacillus plantarum and Weissella confusa were identified from raw red and yellow peppers (RYPs) by partial 16S rRNA gene sequence and subjected to typing by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis. L. plantarum PE21, L. curvatus PE4 and W. confusa PE36 were selected based on the kinetics of growth and acidification, and used as the autochthonous mixed starter for the fermentation of RYPs. A protocol which included blanching at 85 degrees C for 2 min, fermentation at 35 degrees C for 15 h in brine (1%, w/v), and heat treatment at 85 degrees C for 15 min, followed by storage at room temperature for 30 days with and without sunflower seeds oil was set up. Unstarted RYPs subjected to the same treatments were used as the control. Cell numbers of autochthonous starter in the RYPs were ca. 1000 times higher than presumptive lactic acid bacteria in unstarted RYPs. As shown by RAPD-PCR analysis, all three autochthonous strains persisted during processing and storage. Presumptive lactic acid bacteria found in started RYPs progressively decreased during storage, leading to a microbiota mainly consisting of autochthonous starters. Started RYPs showed rapid decrease of pH (<3.7), marked consumption of fermentable carbohydrates, and inhibition of total enterobacteria and yeasts. Unstarted RYPs were subjected to slight acidification (pH ca. 4.87) and considerable contamination by total enterobacteria and yeasts throughout storage. After 30 days of storage, started RYPs had significantly (P<0.05) higher firmness and colour indexes with respect to unstarted RYPs. The microbial and sensory features of started RYPs stored with sunflower seeds oil were almost similar to those of RYPs stored without suspending liquid.

  18. Novel role for the transient potential receptor melastatin 4 channel in guinea pig detrusor smooth muscle physiology

    PubMed Central

    Smith, Amy C.; Hristov, Kiril L.; Cheng, Qiuping; Xin, Wenkuan; Parajuli, Shankar P.; Earley, Scott; Malysz, John

    2013-01-01

    Members of the transient receptor potential (TRP) channel superfamily, including the Ca2+-activated monovalent cation-selective TRP melastatin 4 (TRPM4) channel, have been recently identified in the urinary bladder. However, their expression and function at the level of detrusor smooth muscle (DSM) remain largely unexplored. In this study, for the first time we investigated the role of TRPM4 channels in guinea pig DSM excitation-contraction coupling using a multidisciplinary approach encompassing protein detection, electrophysiology, live-cell Ca2+ imaging, DSM contractility, and 9-phenanthrol, a recently characterized selective inhibitor of the TRPM4 channel. Western blot and immunocytochemistry experiments demonstrated the expression of the TRPM4 channel in whole DSM tissue and freshly isolated DSM cells with specific localization on the plasma membrane. Perforated whole cell patch-clamp recordings and real-time Ca2+ imaging experiments with fura 2-AM, both using freshly isolated DSM cells, revealed that 9-phenanthrol (30 μM) significantly reduced the cation current and decreased intracellular Ca2+ levels. 9-Phenanthrol (0.1–30 μM) significantly inhibited spontaneous, 0.1 μM carbachol-induced, 20 mM KCl-induced, and nerve-evoked contractions in guinea pig DSM-isolated strips with IC50 values of 1–7 μM and 70–80% maximum inhibition. 9-Phenanthrol also reduced nerve-evoked contraction amplitude induced by continuous repetitive electrical field stimulation of 10-Hz frequency and shifted the frequency-response curve (0.5–50 Hz) relative to the control. Collectively, our data demonstrate the novel finding that TRPM4 channels are expressed in guinea pig DSM and reveal their critical role in the regulation of guinea pig DSM excitation-contraction coupling. PMID:23302778

  19. Effects of alismol isolated from Alismatis Rhizoma on calcium-induced contraction in the rabbit thoracic aorta

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matsuda, H.; Kobayashi, G.; Yamahara, J.

    1987-10-12

    The authors examined the inhibitory effects of alismol, a sesquiterpenoid isolated from Alismatis Rhizoma, on vascular contractions induced by high concentrations of K/sup +/ and Ca/sup 2 +/, and on /sup 45/Ca/sup 2 +/ retention in normal and in high K/sup +/-containing medium. Alismol affected neither the resting tension nor the /sup 45/Ca/sup 2 +/ retention in normal medium, but it inhibited sustained contraction and increased /sup 45/Ca/sup 2 +/ retention induced by high K/sup +/ concentrations. Alismol did not affect norepinephrine-induced contractions in normal medium, nor phasic contractions in Ca/sup 2 +/-free medium. These results suggested that alismol inhibitedmore » mainly Ca/sup 2 +/ influx through a voltage-dependent Ca/sup 2 +/ channel. 19 references, 6 figures.« less

  20. Unintended activity in homologous muscle during intended unilateral contractions increases with greater task difficulty.

    PubMed

    Watanabe, Hironori; Kanehisa, Hiroaki; Yoshitake, Yasuhide

    2017-10-01

    The present study aimed to examine (1) the effect of task difficulty on unintended muscle activation (UIMA) levels in contralateral homologous muscle, (2) the difference between young and old adults in degree of UIMA with respect to task difficulty, and (3) temporal correlations between intended and contralateral unintended muscle activity at low frequency during unilateral intended force-matching tasks. Twelve young (21.8 ± 2.4 years) and twelve old (69.9 ± 5.3 years) adult men performed steady isometric abductions with the left index finger at 20-80% of maximal voluntary contraction force. Two task difficulties were set by adjusting the spacing between two bars centered about the target force used for visual feedback on a monitor. The amplitude of surface electromyogram (aEMG) for both hands was calculated and normalized with respect to the maximal value. To determine if oscillations between intended and unintended muscle activities were correlated, cross-correlation function (CCF) of rectified EMG for both hands at low frequency was calculated for samples deemed adequate. The unintended aEMG (right hand) had significant main effects in task difficulty, age, and target force (all P < 0.05) without any interactions. Distinct significant peaks in CCF (0.38 on average, P < 0.05) with small time lags were present between rectified EMGs of intended and unintended muscles in 14 of the 17 samples. The current results indicate that UIMA increases with greater task difficulty regardless of age, and temporal correlations exist between intended and contralateral unintended muscle activities at low frequency.

  1. Enhanced Training by a Systemic Governance of Force Capabilities, Tasks, and Processes

    DTIC Science & Technology

    2013-06-01

    18th ICCRTS “C2 in Underdeveloped, Degraded and Denied Operational Environments” Enhanced Training by a Systemic Governance of Force Capabilities...TITLE AND SUBTITLE Enhanced Training by a Systemic Governance of Force Capabilities, Tasks, and Processes 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...assess, evaluate and accredit the Swedish forces. This paper presents a Systemic Governance of Capabilities, Tasks, and Processes applied to the

  2. The effects of concurrent cognitive tasks on postural sway in healthy subjects.

    PubMed

    Mujdeci, Banu; Turkyilmaz, Didem; Yagcioglu, Suha; Aksoy, Songul

    2016-01-01

    Keeping balance of the upright stance is a highly practiced daily task for healthy adults and is effectively performed without overt attentional control in most. The purpose of this study was to examine the influence of concurrent cognitive tasks on postural sway in healthy participants. This was a prospective study. 20 healthy volunteer subjects were included. The cognitive and balance tasks were performed separately and then, concurrently. Postural control task consisted of 6 conditions (C) of the Sensory Organization Test. The cognitive task consisted of digit rehearsal task of varying presentation and varying levels of difficulty. A statistically significant difference was noted between dual task and no task for C1, C2, C3 and C4 Sensory Organization Test scores (p<0.05). There was no statistically significant difference between dual task versus non-task for C5, C6 and combined Sensory Organization Test scores (p>0.05). During dual task, increase has been determined in postural sway for C1, C2, C3 and C4 for all presentation modes and difficulty levels of the cognitive tasks. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  3. Ca2+ influx in the endothelial cells is required for the bradykinin-induced endothelium-dependent contraction in the porcine interlobar renal artery

    PubMed Central

    Ihara, Eikichi; Derkach, Dmitry N; Hirano, Katsuya; Nishimura, Junji; Nawata, Hajime; Kanaide, Hideo

    2001-01-01

    To determine the mechanism of bradykinin-induced production of endothelium-derived contracting factors, we monitored the changes in cytosolic Ca2+ concentration ([Ca2+]i) in in situ endothelial cells in porcine aortic valvular strips and the changes in [Ca2+]i of smooth muscle cells and force in porcine interlobar renal arterial strips using front-surface fluorometry of fura-2. In the presence of Nω-nitro-l-arginine methyl ester, bradykinin caused an endothelium-dependent transient elevation of [Ca2+]i and contraction in smooth muscle in the interlobar renal artery. This contraction was completely inhibited by a prostaglandin H2/thromboxane A2 receptor antagonist. In the absence of extracellular Ca2+, bradykinin failed to induce contraction. However, replenishing extracellular Ca2+ to 0.75 mm and higher induced an instantaneous contraction. However, replenishing Ca2+per se did not induce any contraction in the absence of bradykinin. Pretreatment with either 10−5m 1-(β-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenethyl)-1H-imidazole hydrochloride (SKF96365) or 0.2 mm Ni2+ abolished the contraction induced by bradykinin in the presence of extracellular Ca2+. Treatment with 10−5m indomethacin completely inhibited the contractile response induced by Ca2+ replenishment, regardless of the timing of its application, before or after the application of bradykinin. In endothelial cells in the valvular strips, bradykinin caused a transient [Ca2+]i elevation in the presence of 1.25 mm extracellular Ca2+, but [Ca2+]i returned to the resting level within 10 min. Neither 10−5m SKF96365 nor 0.2 mm Ni2+ had any effect on the peak [Ca2+]i elevation, but decreased [Ca2+]i in the declining phase. In the absence of extracellular Ca2+, bradykinin induced a transient [Ca2+]i elevation to a level similar to that seen in the presence of 1.25 mm extracellular Ca2+. However, [Ca2+]i then rapidly returned to the prestimulation level within 5 min. Subsequent Ca2+ replenishment to 0.75 mm and higher in the presence of bradykinin elevated [Ca2+]i to significantly higher levels than the resting level seen in the media containing 1.25 mm Ca2+. In conclusion, Ca2+ influx in the endothelial cells is essential for bradykinin to induce endothelium-dependent contraction in the porcine interlobar renal artery. PMID:11483701

  4. Calcium Hypochlorite Solutions: Evaluation of Surface Tension and Effect of Different Storage Conditions and Time Periods over pH and Available Chlorine Content.

    PubMed

    Leonardo, Natália Gomes e Silva; Carlotto, Israel Bangel; Luisi, Simone Bonato; Kopper, Patrícia Maria Poli; Grecca, Fabiana Soares; Montagner, Francisco

    2016-04-01

    The aim of this study was to evaluate the pH and the available chlorine content from sodium hypochlorite (NaOCl) and calcium hypochlorite (Ca[OCl]2) solutions stored in different conditions and time periods and the surface tension of Ca(OCl)2 solutions in comparison with NaOCl. Solutions at 0.5%, 1%, 2.5%, and 5.25% concentrations were prepared. The pH level and the available chlorine content of freshly prepared solutions and solutions stored for 30, 60, and 90 days at 25°C, 4°C, or 37°C were evaluated in a digital pH meter and by titration, respectively. Surface tension was tested using a Du Nouy tensiometer (Sigma 702, Force Tensiometer; Attension, Espoo, Finland). Descriptive and inferential statistical analyses were performed. A precipitate formed by 2.5% and 5.25% Ca(OCl)2 solutions was observed. Ca(OCl)2 showed a higher concentration of available chlorine than NaOCl. Both 2.5% and 5.25% NaOCl and Ca(OCl)2 had a decrease in the available chlorine content when compared with freshly prepared solutions; 0.5% and 1% NaOCl tend to have a lower pH compared with 0.5% and 1% Ca(OCl)2. NaOCl, 5.25%, showed higher pH compared with 5.25% Ca(OCl)2. NaOCl and Ca(OCl)2 in 0.5% and 1% concentrations tend to show a reduced pH level, whereas 2.5% and 5.25% solutions showed an increase in pH. The heat contributed to the instability of the solutions. NaOCl showed lower surface tension values than Ca(OCl)2. Ca(OCl)2 solutions are extremely alkaline and tend to have more available chlorine content than NaOCl but have a higher surface tension than NaOCl. Regarding the available chlorine content, these solutions tend to be stable to 30 days of storage when kept at 4°C or at 25°C. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Thirteen Week Oral Toxicity Study of WR238605 with a Thirteen Week Recovery Period in Rats. Volume 3 of 3

    DTIC Science & Technology

    1993-06-18

    Page 1 REVISED PAGE A u STUDY Mfr CBM, INITIAL (77 DATE-y-Hl^. 5.0 7.0 Contract No.: DAMD17-92-C-2C01 Task Order No.: UIC-5B Study No.: 098 ® i...Report. The results will not be Page 6 REVISED PAGE /?. STUDY Mfr 2M INITIAL: (jLL i OATF- \\yjuftl.’ I I 1’ II II II II II II II...necessary) recovery animals. . Page 7 REVISED PAGE A,. INITIALIZE cninvwyO^g DATE: ><-/*’ fr ?. i u JU ft Contract No. Task Order No. Study No

  6. Near East/South Asia Report

    DTIC Science & Technology

    1985-07-29

    the picture, since we are not living with a new and optimistic 5 -year plan after having completed another rich and ambitious plan. The interview is...adopted a new regulation concerning its contract workers. The workweek has been increased to 48 hours , i.e., raised by 12 hours , to cut down on...tasks. (Text] [Omdurman Domestic Service in Arabic 1500 GMT 29 May 85 EA] NEW ENVOYS--Khartoum, 9 Jun (SUNA)--Foreign Minister Taha Ayyub received

  7. A contraction-related component of slow inward current in dog ventricular muscle and its relation to Na(+)-Ca2+ exchange.

    PubMed Central

    Simurda, J; Simurdová, M; Bravený, P; Sumbera, J

    1992-01-01

    1. The slow inward current component related to contraction (Isic) was studied in voltage clamp experiments on canine ventricular trabeculae at 30 degrees C with the aims of (a) estimating its relation to electrogenic Na(+)-Ca2+ exchange and (b) comparing it with similar currents as reported in cardiac myocytes. 2. Isic may be recorded under conditions of augmented contractility in response to depolarizing pulses below the threshold of the classic slow inward current (presumably mediated by L-type Ca2+ channels). In responses to identical depolarizing clamp pulses the peak value of Isic is directly related to the amplitude of contraction (Fmax). Isic peaks about 60 ms after the onset of depolarization and declines with a half-time of about 110 ms. 3. The voltage threshold of Isic activation is the same as the threshold of contraction. The positive inotropic clamp preconditions shift both thresholds to more negative values of membrane voltage, i.e. below the threshold of the classic slow inward current. 4. Isic may also be recorded as a slowly decaying inwardly directed current 'tail' after depolarizing pulses. In this representation the peak value of Isic changes with duration of the depolarizing pulses, again in parallel with Fmax. In response to pulses shorter than 100 ms both variables increase with depolarization time. If initial conditions remain constant, further prolongation of the pulse does not significantly influence either one (tail currents follow a common envelope). 5. Isic differs from classic slow inward current by: (a) its direct relation to contraction, (b) the slower decay of the current tail on repolarization, (c) slower restitution corresponding to the mechanical restitution, (d) its relative insensitivity to Ca(2+)-blocking agents (the decrease of Isic is secondary to the negative inotropic of Ca(2+)-blocking agents (the decrease of Isic is secondary to the negative inotropic effect) and (e) its disappearance after Sr2+ substitution for Ca2+. 6. The manifestations of Isic in multicellular preparations do not differ significantly from those reported in isolated myocytes (in contrast to calcium current). 7. The analysis of the correlation between Isic and Fmax transients during trains of identical test depolarizing pulses at variable extra- and intracellular ionic concentrations (changes of [Ca2+]o, 50% Li+ substitution for Na+, strophanthidin) indicate that the observed effects conform to the predictions based on a quantitative model of Na(+)-Ca2+ exchange. 8. It is concluded that Isic is activated by a transient increase of [Ca2+]i, in consequence of the release from the reticular stores.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1293284

  8. U.S. Naval Academy Officials Did Not Adhere to Contracting and Gift Policies

    DTIC Science & Technology

    2011-11-07

    Report No. DODIG-2012-017 November 7, 2011 U.S. Naval Academy Officials Did Not Adhere to Contracting and Gift Policies...Contracting and Gift Policies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...HERITAGE AND HISTORY COMMAND SUBJECT: U.S. Naval Academy Officials Did Not Adhere to Contracting and Gift Policies (Report No. DODIG-2012-017) We are

  9. Filter Effectiveness Evaluation

    DTIC Science & Technology

    2013-08-01

    Bramer U.S. Army TARDEC Force Projection Technologies Warren, Michigan Contract No. W56HZV-09- C -0100 (WD17-Task 7) UNCLASSIFIED...No. W56HZV-09- C -0100 (WD17-Task 7) SwRI® Project No. 08.14734.17.290 UNCLASSIFIED: Distribution Statement A. Approved for public release...W56HZV-09- C -0100 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Canant, Philip A.; Bessee, Gary B.; Hutzler, Scott A. 5d. PROJECT

  10. A Design Methodology and Prototype for the Reserve Training Support System.

    DTIC Science & Technology

    1985-03-01

    guaranteeing that t d) taLIeS tat are ftn joined togjther art also stored to3Ltner. Clusterin- S Otal’ly transprent o ,ll :ueiin aloi -It the Ja Ca...ACDUTRA 23-JAN-85 G C G G G 2. MIDDLE LEVEL W INSLOW SEEGER WINSLOW NAME 30-JAN-85 Y G C G WINSLCW SEGER WINSLOW RUIC BILLET 04-FEB-35 Y Y Y Y RINSLOW

  11. Blebbistatin, a myosin II inhibitor, suppresses Ca(2+)-induced and "sensitized"-contraction of skinned tracheal muscles from guinea pig.

    PubMed

    Yumoto, Masatoshi; Watanabe, Masaru

    2013-01-01

    Blebbistatin, a potent inhibitor of myosin II, has inhibiting effects on Ca(2+)-induced contraction and contractile filament organization without affecting the Ca(2+)-sensitivity to the force and phosphorylation level of myosin regulatory light chain (MLC20) in skinned (cell membrane permeabilized) taenia cecum from the guinea pig (Watanabe et al., Am J Physiol Cell Physiol. 2010; 298: C1118-26). In the present study, we investigated blebbistatin effects on the contractile force of skinned tracheal muscle, in which myosin filaments organization is more labile than that in the taenia cecum. Blebbistatin at 10 μM or higher suppressed Ca(2+)-induced tension development at any given Ca(2+) concentration, but had little effects on the Ca(2+)- induced myosin light chain phosphorylation. Also blebbistatin at 10 μM and higher significantly suppressed GTP-γS-induced "sensitized" force development. Since the force inhibiting effects of blebbistatin on the skinned trachea were much stronger than those in skinned taenia cecum, blebbistatin might directly affect myosin filaments organization.

  12. Evaluation of Laboratory Scale Testing of Tunnels and Tunnel Intersections. Volume 1

    DTIC Science & Technology

    1991-11-01

    Bakhtar, K. and DiBona , B. G., Dynamic Loading Experiments on Model Underground Structures," DNA-TR-85-387, prepared by Terra Tek, Inc. for Defense...34, TR 84-01, prepared by Terra Tek, Inc, for DNA Contract No. DNA 001-82-C-0253. DNA TR-85-387 Bakhtar, K. and DiBona , B. G., Dynamic Loading Experiments

  13. Effects of substance P on spontaneous contraction in the flexure region of the guinea pig colon.

    PubMed

    Chowdhury, J U; Nahar, N S

    2007-01-01

    Effects of Substance P on spontaneous contractions of the circular muscle of the flexure region of guinea pig colon were studied by mechanical tension recording. Substance P (3 nM-10 nM) produced tonic contraction associated with phasic activities but the contraction was found stronger at higher concentration. Verapamil (3 microM), a voltage dependent L-type Ca(2+) channel blocker completely blocked the spontaneous activities and also Substance P induced contraction. These results suggest that Substance P produce contraction by Ca(2+) influx and the Ca(2+) influx occurs by activating verapamil sensitive Ca(2+) channel.

  14. Acute Effects of Static Stretching of Hamstring on Performance and Anterior Cruciate Ligament Injury Risk During Stop-Jump and Cutting Tasks in Female Athletes.

    PubMed

    Ruan, Mianfang; Zhang, Qiang; Wu, Xie

    2017-05-01

    Ruan, M, Zhang, Q, and Wu, X. Acute effects of static stretching of hamstring on performance and anterior cruciate ligament injury risk during stop-jump and cutting tasks in female athletes. J Strength Cond Res 31(5): 1241-1250, 2017-There is limited research investigating antagonist stretch. The purpose of this study was to evaluate the influence of static stretching of hamstrings (SSH) on performance and anterior cruciate ligament (ACL) injury risk during stop-jump and 180° cutting tasks. Twelve female college athletes (age 20.8 ± 0.7 years; height 1.61 ± 0.05 m; mass 54.25 ± 4.22 kg) participated in this study. Subjects performed stop-jump and 180° cutting tasks under 2 conditions: after warm-up with 4 × 30 seconds SSH or after warm-up without SSH. Three-dimensional kinematic and kinetic data as well as electromyography of biceps femoris, rectus femoris, vastus medialis, and gastrocnemius medialis were collected during testing. Static stretching of hamstrings significantly enhanced jump height by 5.1% (p = 0.009) but did not change the takeoff speed of cutting. No significant changes in peak knee adduction moment or peak anterior tibia shear force were observed with SSH regardless of the task. The peak lateral tibia shear force during cutting was significantly (p = 0.036) reduced with SSH. The co-contraction of hamstring and quadriceps during the preactivation (stop-jump: p = 0.04; cutting: p = 0.05) and downward phases (stop-jump: p = 0.04; cutting: p = 0.05) was significantly reduced after SSH regardless of the task. The results suggest that SSH enhanced the performance of stop-jump because of decreased co-contraction of hamstring and quadriceps but did not change the performance of cutting. In addition, SSH did not increase ACL injury risk during stop-jump and cutting tasks and even reduced medial-lateral knee loading during cutting.

  15. Acute Effects of Static Stretching of Hamstring on Performance and Anterior Cruciate Ligament Injury Risk During Stop-Jump and Cutting Tasks in Female Athletes

    PubMed Central

    Ruan, Mianfang; Zhang, Qiang

    2017-01-01

    Abstract Ruan, M, Zhang, Q, and Wu, X. Acute effects of static stretching of hamstring on performance and anterior cruciate ligament injury risk during stop-jump and cutting tasks in female athletes. J Strength Cond Res 31(5): 1241–1250, 2017—There is limited research investigating antagonist stretch. The purpose of this study was to evaluate the influence of static stretching of hamstrings (SSH) on performance and anterior cruciate ligament (ACL) injury risk during stop-jump and 180° cutting tasks. Twelve female college athletes (age 20.8 ± 0.7 years; height 1.61 ± 0.05 m; mass 54.25 ± 4.22 kg) participated in this study. Subjects performed stop-jump and 180° cutting tasks under 2 conditions: after warm-up with 4 × 30 seconds SSH or after warm-up without SSH. Three-dimensional kinematic and kinetic data as well as electromyography of biceps femoris, rectus femoris, vastus medialis, and gastrocnemius medialis were collected during testing. Static stretching of hamstrings significantly enhanced jump height by 5.1% (p = 0.009) but did not change the takeoff speed of cutting. No significant changes in peak knee adduction moment or peak anterior tibia shear force were observed with SSH regardless of the task. The peak lateral tibia shear force during cutting was significantly (p = 0.036) reduced with SSH. The co-contraction of hamstring and quadriceps during the preactivation (stop-jump: p = 0.04; cutting: p = 0.05) and downward phases (stop-jump: p = 0.04; cutting: p = 0.05) was significantly reduced after SSH regardless of the task. The results suggest that SSH enhanced the performance of stop-jump because of decreased co-contraction of hamstring and quadriceps but did not change the performance of cutting. In addition, SSH did not increase ACL injury risk during stop-jump and cutting tasks and even reduced medial-lateral knee loading during cutting. PMID:28118311

  16. An Automated Individual Training Record Management System (Prototype) United States Marine Corps

    DTIC Science & Technology

    1984-03-01

    PERFORMING ORG. REPORT NUMBER 7. AUTHO(a) 9. CONTRACT OR GRANT NUMBER(@) Ronald E. Pruiett David P. Haeusler 9. PERFORMING ORGANIZATION NAME AND ADDRESS...10. PROGRAM ELEMENT. PROJECT. TASK AREA & WORK UNIT NUMBERS Naval Postgraduate School Monterey, CA 93943 11. CONTROL.LING OFFICE NAME AND ADDRESS 12...ane individuel levels of performance . Since the focus is cn individual training ard individual testing, data m s atntained for each individual in a

  17. A Multicenter, Randomized Controlled Trial of Cerebrospinal Fluid Drainage in Acute Spinal Cord Injury

    DTIC Science & Technology

    2015-10-01

    Injury PRINCIPAL INVESTIGATOR: Nicholas Theodore, MD CONTRACTING ORGANIZATION: Dignity Health San Francisco, CA 94107-1773 REPORT DATE: October 2015...TASK NUMBER E-Mail: Nicholas.Theodore@bnaneuro.net 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Dignity Health AND ADDRESS...patients aims to reduce cell death and axonal damage leading to improved neurological function in patients. 2. KEYWORDS acute spinal cord injury

  18. Reproducing early Martian atmospheric carbon dioxide partial pressure by modeling the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops on Mars

    NASA Astrophysics Data System (ADS)

    Berk, Wolfgang; Fu, Yunjiao; Ilger, Jan-Michael

    2012-10-01

    The well defined composition of the Comanche rock's carbonate (Magnesite0.62Siderite0.25Calcite0.11Rhodochrosite0.02) and its host rock's composition, dominated by Mg-rich olivine, enable us to reproduce the atmospheric CO2partial pressure that may have triggered the formation of these carbonates. Hydrogeochemical one-dimensional transport modeling reveals that similar aqueous rock alteration conditions (including CO2partial pressure) may have led to the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops (Gusev Crater) and also in the ultramafic rocks exposed in the Nili Fossae region. Hydrogeochemical conditions enabling the formation of Mg-rich solid solution carbonate result from equilibrium species distributions involving (1) ultramafic rocks (ca. 32 wt% olivine; Fo0.72Fa0.28), (2) pure water, and (3) CO2partial pressures of ca. 0.5 to 2.0 bar at water-to-rock ratios of ca. 500 molH2O mol-1rock and ca. 5°C (278 K). Our modeled carbonate composition (Magnesite0.64Siderite0.28Calcite0.08) matches the measured composition of carbonates preserved in the Comanche rocks. Considerably different carbonate compositions are achieved at (1) higher temperature (85°C), (2) water-to-rock ratios considerably higher and lower than 500 mol mol-1 and (3) CO2partial pressures differing from 1.0 bar in the model set up. The Comanche rocks, hosting the carbonate, may have been subjected to long-lasting (>104 to 105 years) aqueous alteration processes triggered by atmospheric CO2partial pressures of ca. 1.0 bar at low temperature. Their outcrop may represent a fragment of the upper layers of an altered olivine-rich rock column, which is characterized by newly formed Mg-Fe-Ca solid solution carbonate, and phyllosilicate-rich alteration assemblages within deeper (unexposed) units.

  19. Basal activity of voltage-gated Ca(2+) channels controls the IP3-mediated contraction by α(1)-adrenoceptor stimulation of mouse aorta segments.

    PubMed

    Leloup, Arthur J; Van Hove, Cor E; De Meyer, Guido R Y; Schrijvers, Dorien M; Fransen, Paul

    2015-08-05

    α1-Adrenoceptor stimulation of mouse aorta causes intracellular Ca(2+) release from sarcoplasmic reticulum Ca(2+) stores via stimulation of inositoltriphosphate (IP3) receptors. It is hypothesized that this Ca(2+) release from the contractile and IP3-sensitive Ca(2+) store is under the continuous dynamic control of time-independent basal Ca(2+) influx via L-type voltage-gated Ca(2+) channels (LCC) residing in their window voltage range. Mouse aortic segments were α1-adrenoceptor stimulated with phenylephrine in the absence of external Ca(2+) (0Ca) to measure phasic isometric contractions. They gradually decreased with time in 0Ca, were inhibited with 2-aminoethoxydiphenyl borate, and declined with previous membrane potential hyperpolarization (levcromakalim) or with previous inhibition of LCC (diltiazem). Former basal stimulation of LCC with depolarization (15 mM K(+)) or with BAY K8644 increased the subsequent phasic contractions by phenylephrine in 0Ca. Although exogenous NO (diethylamine NONOate) reduced the phasic contractions by phenylephrine, stimulation of endothelial cells with acetylcholine in 0Ca failed to attenuate these phasic contractions. Finally, inhibition of the basal release of NO with N(Ω)-nitro-L-arginine methyl ester also attenuated the phasic contractions by phenylephrine. Results indicated that α1-adrenoceptor stimulation with phenylephrine causes phasic contractions, which are controlled by basal LCC and endothelial NO synthase activity. Endothelial NO release by acetylcholine was absent in 0Ca. Given the growing interest in the active regulation of arterial compliance, the dependence of contractile SR Ca(2+) store-refilling in basal conditions on the activity of LCC and basal eNOS may contribute to a more thorough understanding of physiological mechanisms leading to arterial stiffness. Copyright © 2015. Published by Elsevier B.V.

  20. Market-Based Multirobot Coordination: A Survey and Analysis

    DTIC Science & Technology

    2005-04-01

    observe new information about their surroundings. Market -based approaches can often seamlessly incorporate online tasks by auctioning new tasks as they... Market -Based Multirobot Coordination: A Survey and Analysis M. Bernardine Dias, Robert Zlot, Nidhi Kalra, and Anthony Stentz CMU-RI-TR-05-13 April...00-00-2005 to 00-00-2005 4. TITLE AND SUBTITLE Market -Based Multirobot Coordination: A Survey and Analysis 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  1. [Interaction between TRPC1 and STIM1 in calcium sensing receptor mediated calcium influx and nitric oxide production in human umbilical vein endothelial cells].

    PubMed

    Wang, L M; Zhong, H; Tang, N; Pang, L J; Zhang, C J; He, F

    2017-11-24

    Objective: To investigate the interaction of Ca(2+) protein TRPC1 and STIM1 in extracellular Ca(2+) -sensing receptor (CaR)-induced extracellular Ca(2+) influx and the production of nitric oxide (NO). Methods: Human umbilical vein endothelial cells (HUVECs) were cultured and incubated with CaR agonist spermine (activating store-operates cation channels (SOC) and receptor-operated channels (ROC)), CaR negative allosteric modulator Calhex231 (blocking SOC, activating ROC) and ROC analogue TPA (activating ROC, blocking SOC), protein kinase C (PKC) inhibitor Ro31-8220, PKCs and PKCμ inhibitor Go6967(activate SOC, blocking ROC), respectively. The interaction of TRPC1 and STIM1 was determined using the immunofluorescence methods. The interaction between TRPC1 and STIM1 were examined by Co-immuno precipitation. The HUVECs were divided into: TRPC1 and STIM1 short hairpin RNA group (shTRPC1+ shSTIM1 group), vehicle-TRPC1+ vehicle-STIM1 group and control group. The cells were incubated with four different treatments under the action of above mentioned interventions, intracellular Ca(2+) concentration ([Ca(2+) ](i)) was detected using the fluorescence Ca(2+) indicator Fura-2/AM, the production of NO was determined by DAF-FM. Results: (1) The expression of TRPC1 and STIM1 proteins levels in HUVECs: Under the confocal microscope, TRPC1 and STIM1 protein expression showed masculine gender, both located in cytoplasm in the normal control group. Post incubation with Calhex231+ TPA, Ro31-8220 and Go6967, TRPC1 and STIM1 positioned in cytoplasm was significantly reduced, and the combined TRPC1 and STIM1 was also significantly reduced. (2) The interaction of TRPC1 and STIM1 in HUVECs: The relative ratios of Calhex231+ TPA+ Spermine+ Ca(2+) group, Ro31-8220+ Spermine+ Ca(2+) group and Go6976+ Spermine+ Ca(2+) group STIM1/TRPC1 and TRPC1/STIM1 were as follows: (25.98±2.17)% and (44.10±4.01)%, (20.85±1.01)% and (46.31±3.47)%, (23.88±2.05)% and (39.65±2.91)%, which were significantly lower than those in the control group (100.00±4.66)% and (100.00±6.40)% and in the Spermine+ Ca(2+) group (106.04±2.45)% and (107.78±2.66)% (all P <0.05). (3) The influence of joint TRPC1 and STIM1 transfection to four different drugs treated HUVECs on [Ca(2+) ](i) and NO generation: The changes of two excitation fluorescence intensity ratio and NO net fluorescence intensity values were consistent, [Ca(2+) ](i) and NO net fluorescence intensity values were significantly lower in the experimental group than the control group and the vehicle group (all P <0.05), while which were similar between the vehicle group and control group (all P >0.05). Conclusions: Our results indicate that TRPC1 and STIM1 jointly regulate CaR-mediated Ca(2+) influx and nitric oxide generation in HUVECs in the form of binary complex.

  2. Investigation of the Structure and Dynamics of Electrolytes in solvents Used for Primary and Secondary Li-Batteries.

    DTIC Science & Technology

    1985-02-01

    permittivitles in the concentration range 0.05M to 0.3M, frequency range 1 to 90 GHz are Intepreted by two Debye relaxation processes, one due to the...and are co-authors of the published papers. They have not received any financial reward from the contract funds. FILMED 6-85 DTIC

  3. Central activation, metabolites, and calcium handling during fatigue with repeated maximal isometric contractions in human muscle.

    PubMed

    Cairns, Simeon P; Inman, Luke A G; MacManus, Caroline P; van de Port, Ingrid G L; Ruell, Patricia A; Thom, Jeanette M; Thompson, Martin W

    2017-08-01

    To determine the roles of calcium (Ca 2+ ) handling by sarcoplasmic reticulum (SR) and central activation impairment (i.e., central fatigue) during fatigue with repeated maximal voluntary isometric contractions (MVC) in human muscles. Contractile performance was assessed during 3 min of repeated MVCs (7-s contraction, 3-s rest, n = 17). In ten participants, in vitro SR Ca 2+ -handling, metabolites, and fibre-type composition were quantified in biopsy samples from quadriceps muscle, along with plasma venous [K + ]. In 11 participants, central fatigue was compared using tetanic stimulation superimposed on MVC in quadriceps and adductor pollicis muscles. The decline of peak MVC force with fatigue was similar for both muscles. Fatigue resistance correlated directly with % type I fibre area in quadriceps (r = 0.77, P = 0.009). The maximal rate of ryanodine-induced Ca 2+ -release and Ca 2+ -uptake fell by 31 ± 26 and 28 ± 13%, respectively. The tetanic force depression was correlated with the combined reduction of ATP and PCr, and increase of lactate (r = 0.77, P = 0.009). Plasma venous [K + ] increased from 4.0 ± 0.3 to 5.4 ± 0.8 mM over 1-3-min exercise. Central fatigue occurred during the early contractions in the quadriceps in 7 out of 17 participants (central activation ratio fell from 0.98 ± 0.05 to 0.86 ± 0.11 at 1 min), but dwindled at exercise cessation. Central fatigue was seldom apparent in adductor pollicis. Fatigue with repeated MVC in human limb muscles mainly involves peripheral aspects which include impaired SR Ca 2+ -handling and we speculate that anaerobic metabolite changes are involved. A faster early force loss in quadriceps muscle with some participants is attributed to central fatigue.

  4. Hydrogen sulphide inhibits carbachol-induced contractile responses in β-escin permeabilized guinea-pig taenia caecum.

    PubMed

    Denizalti, Merve; Durlu-Kandilci, N Tugba; Bozkurt, T Emrah; Sahin-Erdemli, Inci

    2011-05-11

    Hydrogen sulphide (H(2)S) is an endogenous mediator producing a potent relaxation response in vascular and non-vascular smooth muscles. While ATP-sensitive potassium channels are mainly involved in this relaxant effect in vascular smooth muscle, the mechanism in other smooth muscles has not been revealed yet. In the present study, we investigated how H(2)S relaxes non-vascular smooth muscle by using intact and β-escin permeabilized guinea-pig taenia caecum. In intact tissues, concentration-dependent relaxation response to H(2)S donor NaHS in carbachol-precontracted preparations did not change in the presence of a K(ATP) channel blocker glibenclamide, adenylate cyclase inhibitor SQ-22536, guanylate cyclase inhibitor ODQ, protein kinase A inhibitor KT-5720, protein kinase C inhibitor H-7, tetrodotoxin, apamin/charybdotoxin, NOS inhibitor L-NAME and cyclooxygenase inhibitor indomethacin. We then studied how H(2)S affected carbachol- or Ca(2+)-induced contractions in permeabilized tissues. When Ca(2+) was clamped to a constant value (pCa6), a further contraction could be elicited by carbachol that was decreased by NaHS. This decrease in contraction was reversed by catalase but not by superoxide dismutase or N-acetyl cysteine. The sarcoplasmic reticulum Ca(2+)-ATPase pump inhibitor, cyclopiazonic acid, also decreased the carbachol-induced contraction that was further inhibited by NaHS. Mitochondrial proton pump inhibitor carbonyl cyanide p-trifluromethoxyphenylhydrazone also decreased the carbachol-induced contraction but this was not additionally changed by NaHS. The carbachol-induced Ca(2+) sensitization, calcium concentration-response curves, IP(3)- and caffeine-induced contractions were not affected by NaHS. In conclusion, we propose that hydrogen peroxide and mitochondria may have a role in H(2)S-induced relaxation response in taenia caecum. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Selective inhibition of histamine-evoked Ca2+ signals by compartmentalized cAMP in human bronchial airway smooth muscle cells.

    PubMed

    Dale, Philippa; Head, Victoria; Dowling, Mark R; Taylor, Colin W

    2018-05-01

    Intracellular Ca 2+ and cAMP typically cause opposing effects on airway smooth muscle contraction. Receptors that stimulate these pathways are therapeutic targets in asthma and chronic obstructive pulmonary disease. However, the interactions between different G protein-coupled receptors (GPCRs) that evoke cAMP and Ca 2+ signals in human bronchial airway smooth muscle cells (hBASMCs) are poorly understood. We measured Ca 2+ signals in cultures of fluo-4-loaded hBASMCs alongside measurements of intracellular cAMP using mass spectrometry or [ 3 H]-adenine labeling. Interactions between the signaling pathways were examined using selective ligands of GPCRs, and inhibitors of Ca 2+ and cAMP signaling pathways. Histamine stimulated Ca 2+ release through inositol 1,4,5-trisphosphate (IP 3 ) receptors in hBASMCs. β 2 -adrenoceptors, through cAMP and protein kinase A (PKA), substantially inhibited histamine-evoked Ca 2+ signals. Responses to other Ca 2+ -mobilizing stimuli were unaffected by cAMP (carbachol and bradykinin) or minimally affected (lysophosphatidic acid). Prostaglandin E 2 (PGE 2 ), through EP 2 and EP 4 receptors, stimulated formation of cAMP and inhibited histamine-evoked Ca 2+ signals. There was no consistent relationship between the inhibition of Ca 2+ signals and the amounts of intracellular cAMP produced by different stimuli. We conclude that β-adrenoceptors, EP 2 and EP 4 receptors, through cAMP and PKA, selectively inhibit Ca 2+ signals evoked by histamine in hBASMCs, suggesting that PKA inhibits an early step in H 1 receptor signaling. Local delivery of cAMP within hyperactive signaling junctions mediates the inhibition. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Shock Spectrum Calculation from Acceleration Time Histories

    DTIC Science & Technology

    1980-09-01

    CLASSIFICATIONe OF THIS PAGE (Uh-e DOg ~ 9--t)____________________ REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM I. REPRT NU9911ACCUIISIO6 NO .3ASCCSPICHT’S...SCE. Oakland CA NAVSCOLCECOFF C35 Port Hueneme. CA,. CO, Code C44A Porn Hueneme. CA NAVSEASYSCOM Code 05M13 (Newhouse) Wash DC; Code 6212, Wash DC

  7. Arrhythmia causes lipid accumulation and reduced glucose uptake.

    PubMed

    Lenski, Matthias; Schleider, Gregor; Kohlhaas, Michael; Adrian, Lucas; Adam, Oliver; Tian, Qinghai; Kaestner, Lars; Lipp, Peter; Lehrke, Michael; Maack, Christoph; Böhm, Michael; Laufs, Ulrich

    2015-01-01

    Atrial fibrillation (AF) is characterized by irregular contractions of atrial cardiomyocytes and increased energy demand. The aim of this study was to characterize the influence of arrhythmia on glucose and fatty acid (FA) metabolism in cardiomyocytes, mice and human left atrial myocardium. Compared to regular pacing, irregular (pseudo-random variation at the same number of contractions/min) pacing of neonatal rat cardiomyocytes induced shorter action potential durations and effective refractory periods and increased diastolic [Ca(2+)]c. This was associated with the activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and AMP-activated protein kinase (AMPK). Membrane expression of fatty acid translocase (FAT/CD36) and (14)C-palmitic acid uptake were augmented while membrane expression of glucose transporter subtype 4 (GLUT-4) as well as (3)H-glucose uptake were reduced. Inhibition of AMPK and CaMKII prevented these arrhythmia-induced metabolic changes. Similar alterations of FA metabolism were observed in a transgenic mouse model (RacET) for spontaneous AF. Consistent with these findings samples of left atrial myocardium of patients with AF compared to matched samples of patients with sinus rhythm showed up-regulation of CaMKII and AMPK and increased membrane expression of FAT/CD36, resulting in lipid accumulation. These changes of FA metabolism were accompanied by decreased membrane expression of GLUT-4, increased glycogen content and increased expression of the pro-apoptotic protein bax. Irregular pacing of cardiomyocytes increases diastolic [Ca(2+)]c and activation of CaMKII and AMPK resulting in lipid accumulation, reduced glucose uptake and increased glycogen synthesis. These metabolic changes are accompanied by an activation of pro-apoptotic signalling pathways.

  8. Task Force Delay Study. Denver Stapleton International Airport, Volume II.

    DTIC Science & Technology

    1980-03-01

    Stephen L. 11. Hockaday Manager Sl H/j c 2nclosure cc: x. Fred Jaeger bcc: Mr. Herb Hubbard, UAL TFD Correspondence H. Fan 0 JI-. *~ ~ E ~ n ti ~’L1 -J (D...34 Attachment E contains a list of additional delay experiments discussed at the previous Task Force meeting. I I P M. M. &6 Co. Mr. Phillip J. LaRochelle March... E -05B Western. C-01, C7.O3, C-05, CO2 , C-04, C-06, Continental,, C-07, C-09, C-11, C-15, C-10, C-12, C-14, C-16 Trans World,, D-01, D-03, D-05, D-07

  9. Microwave Absorption Properties of La0.8Ca0.2-xAgxMnO3 (x=0.05; x=0.15) Synthesized by Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Kurniawan, B.; Laksmi, W.; Sahara, N. A.

    2018-04-01

    Microwave absorption properties of La0.8Ca0.2-xAgxMnO3 (x= 0.05; 0.15) is reported in this paper. Lanthanum manganite materials was reported as a potential absorber material [1][2][3]. In this paper, the material was synthesized by sol-gel method, calcined at 550°C, and sintered at 900°C. The material was characterized by X-Ray Diffractometer (XRD), and we found that the materials were single phased. Through SEM-EDS characterization it is found that the materials have compositional purity. The resistivity of the materials is obtained by four point probe method, and it is shown that Ag doped decreases the resistivity of the materials. Reflection loss of La0.8Ca0.15Ag0.05MnO3 reaches -4.470 dB and La0.8Ca0.05Ag0.15MnO3 reaches - 7.953 dB.

  10. Ca2+–calmodulin-dependent protein kinase II represses cardiac transcription of the L-type calcium channel α1C-subunit gene (Cacna1c) by DREAM translocation

    PubMed Central

    Ronkainen, Jarkko J; Hänninen, Sandra L; Korhonen, Topi; Koivumäki, Jussi T; Skoumal, Reka; Rautio, Sini; Ronkainen, Veli-Pekka; Tavi, Pasi

    2011-01-01

    Abstract Recent studies have demonstrated that changes in the activity of calcium–calmodulin-dependent protein kinase II (CaMKII) induce a unique cardiomyocyte phenotype through the regulation of specific genes involved in excitation–contraction (E–C)-coupling. To explain the transcriptional effects of CaMKII we identified a novel CaMKII-dependent pathway for controlling the expression of the pore-forming α-subunit (Cav1.2) of the L-type calcium channel (LTCC) in cardiac myocytes. We show that overexpression of either cytosolic (δC) or nuclear (δB) CaMKII isoforms selectively downregulate the expression of the Cav1.2. Pharmacological inhibition of CaMKII activity induced measurable changes in LTCC current density and subsequent changes in cardiomyocyte calcium signalling in less than 24 h. The effect of CaMKII on the α1C-subunit gene (Cacna1c) promoter was abolished by deletion of the downstream regulatory element (DRE), which binds transcriptional repressor DREAM/calsenilin/KChIP3. Imaging DREAM–GFP (green fluorescent protein)-expressing cardiomyocytes showed that CaMKII potentiates the calcium-induced nuclear translocation of DREAM. Thereby CaMKII increases DREAM binding to the DRE consensus sequence of the endogenous Cacna1c gene. By mathematical modelling we demonstrate that the LTCC downregulation through the Ca2+–CaMKII–DREAM cascade constitutes a physiological feedback mechanism enabling cardiomyocytes to adjust the calcium intrusion through LTCCs to the amount of intracellular calcium detected by CaMKII. PMID:21486818

  11. Low Striatal Dopamine D2-type Receptor Availability is Linked to Simulated Drug Choice in Methamphetamine Users.

    PubMed

    Moeller, Scott J; Okita, Kyoji; Robertson, Chelsea L; Ballard, Michael E; Konova, Anna B; Goldstein, Rita Z; Mandelkern, Mark A; London, Edythe D

    2018-03-01

    Individuals with drug use disorders seek drugs over other rewarding activities, and exhibit neurochemical deficits related to dopamine, which is involved in value-based learning and decision-making. Thus, a dopaminergic disturbance may underpin drug-biased choice in addiction. Classical drug-choice assessments, which offer drug-consumption opportunities, are inappropriate for addicted individuals seeking treatment or abstaining. Fifteen recently abstinent methamphetamine users and 15 healthy controls completed two laboratory paradigms of 'simulated' drug choice (choice for drug-related vs affectively pleasant, unpleasant, and neutral images), and underwent positron emission tomography measurements of dopamine D2-type receptor availability, indicated by binding potential (BP ND ) for [ 18 F]fallypride. Thirteen of the methamphetamine users and 10 controls also underwent [ 11 C]NNC112 PET scans to measure dopamine D1-type receptor availability. Group analyses showed that, compared with controls, methamphetamine users chose to view more methamphetamine-related images on one task, with a similar trend on the second task. Regression analyses showed that, on both tasks, the more methamphetamine users chose to view methamphetamine images, specifically vs pleasant images (the most frequently chosen images across all participants), the lower was their D2-type BP ND in the lateral orbitofrontal cortex, an important region in value-based choice. No associations were observed with D2-type BP ND in striatal regions, or with D1-type BP ND in any region. These results identify a neurochemical correlate for a laboratory drug-seeking paradigm that can be administered to treatment-seeking and abstaining drug-addicted individuals. More broadly, these results refine the central hypothesis that dopamine-system deficits contribute to drug-biased decision-making in addiction, here showing a role for the orbitofrontal cortex.

  12. A Benchmark Study of Large Contract Supplier Monitoring Within DOD and Private Industry

    DTIC Science & Technology

    1994-03-01

    83 2. Long Term Supplier Relationships ...... .. 84 3. Global Sourcing . . . . . . . . . . . . .. 85 4. Refocusing on Customer Quality...monitoring and recognition, reduced number of suppliers, global sourcing, and long term contractor relationships . These initiatives were then compared to DCMC...on customer quality. 14. suBJE.C TERMS Benchmark Study of Large Contract Supplier Monitoring. 15. NUMBER OF PAGES108 16. PRICE CODE 17. SECURITY

  13. Effects of papaverine on carbachol- and high K+ -induced contraction in the bovine abomasum.

    PubMed

    Kaneda, Takeharu; Saito, Erika; Kanda, Hidenori; Urakawa, Norimoto; Shimizu, Kazumasa

    2015-10-01

    The effects of papaverine on carbachol (CCh) -and high K(+)- induced contraction in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM) -and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent manner in association with increases in the cAMP or cGMP contents, whereas papaverine increased cGMP contents only at 30 µM. Changes in the extracellular Ca(2+) from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high K(+)-depolarized muscles, but papaverine-induced relaxation did not change. Furthermore, papaverine (30 µM) and NaCN (300 µM) decreased the creatine phosphate contents. These results suggest that the relaxing effects of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy metabolism.

  14. Contribution of Rho kinase to the early phase of the calcium-contraction coupling in airway smooth muscle.

    PubMed

    Mbikou, Prisca; Fajmut, Ales; Brumen, Milan; Roux, Etienne

    2011-02-01

    We investigated theoretically and experimentally the role of Rho kinase (RhoK) in Ca(2+)-contraction coupling in rat airways. Isometric contraction was measured on tracheal, extrapulmonary and intrapulmonary bronchial rings. Intracellular [Ca(2+)] was recorded in freshly isolated tracheal myocytes. Stimulation by carbachol (0.3 and 10 μm) and 50 mm external KCl induced a short-time, Hill-shaped contraction obtained within 90 s, followed by a sustained or an additional delayed contraction. Responses of [Ca(2+)](i) to acetylcholine consisted in a fast peak followed by a plateau and, in 42% of the cells, superimposed Ca(2+) oscillations. The RhoK inhibitor Y27632 (10 μm) did not alter the [Ca(2+)](i) response. Whatever the agonist, Y27632 did not modify the basal tension but decreased the amplitude of the short-duration response, without altering the additional delayed contraction. The Myosin Light Chain Phosphatase (MLCP) inhibitor calyculin A increased the basal tension and abolished the effect of RhoK. KN93 (Ca(2+)-calmodulin-dependent protein kinase II inhibitor) and DIDS (inhibitor of Ca(2+)-activated Cl(-) channels) had no influence on the RhoK effect. We built a theoretical model of Ca(2+)-dependent active/inactive RhoK ratio and subsequent RhoK-dependent MLCP inactivation, which was further coupled with a four-state model of the contractile apparatus and Ca(2+)-dependent MLCK activation. The model explains the time course of the short-duration contraction and the role of RhoK by Ca(2+)-dependent activation of MLCK and RhoK, which inactivates MLCP. Oscillatory and non-oscillatory [Ca(2+)](i) responses result in a non-oscillatory contraction, the amplitude of which is encoded by the plateau value and oscillation frequency. In conclusion, Ca(2+)-dependent but CaMK II-independent RhoK activation contributes to the early phase of the contractile response via MLCP inhibition.

  15. Effects of methyl p-hydroxybenzoate (methyl paraben) on Ca2+ concentration and histamine release in rat peritoneal mast cells

    PubMed Central

    Fukugasako, Sanae; Ito, Shinichi; Ikemoto, Yoshimi

    2003-01-01

    Mechanisms of methyl p-hydroxybenzoate (methyl paraben) action in allergic reactions were investigated by measuring the intracellular Ca2+ concentration ([Ca2+]i) and histamine release in rat peritoneal mast cells (RPMCs). In the presence or absence of extracellular Ca2+, methyl paraben (0.1–10 mM) increased [Ca2+]i, in a concentration-dependent manner. Under both the conditions, methyl paraben alone did not evoke histamine release. In RPMCs pretreated with a protein kinase C (PKC) activator (phorbol 12-myristate 13-acetate (PMA) 3 and 10 nM), methyl paraben (0.3–3 mM) induced histamine release. However, a high concentration (10 mM) of the agent did not increase the histamine release. U73122 (0.1 and 0.5 μM), an inhibitor of phospholipase C (PLC), significantly inhibited the methyl paraben-induced histamine release in PMA-pretreated RPMCs. U73343 (0.5 μM), an inactive analogue of U73122, did not inhibit the histamine release caused by methyl paraben. In Ca2+-free solution, PLC inhibitors (U73122 0.1 and 0.5 μM, D609 1–10 μM) inhibited the methyl paraben-induced increase in [Ca2+]i, whereas U73343 (0.5 μM) did not. Xestospongin C (2–20 μM) and 2 aminoethoxydiphenyl borate (30 and 100 μM), blockers of the inositol 1,4,5-trisphosphate (IP3) receptor, inhibited the methyl paraben-induced increase in [Ca2+]i in Ca2+-free solution. In conclusion, methyl paraben causes an increase in [Ca2+]i, which may be due to release of Ca2+ from storage sites by IP3 via activation of PLC in RPMCs. In addition, methyl paraben possibly has some inhibitory effects on histamine release via unknown mechanisms. PMID:12770943

  16. Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

    PubMed

    Barclay, C J

    2012-12-01

    The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

  17. Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles

    PubMed Central

    Barclay, C J

    2012-01-01

    The aims of this study were to quantify the Ca2+ release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca2+ release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca2+ release was quantified from the amount of ATP used to remove Ca2+ from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca2+ pump ATP turnover. At 20°C, Ca2+ release in response to a single stimulus was 34 and 84 μmol (kg muscle)−1 for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg−1; EDL, 168 μmol kg−1). Delivery of another stimulus within 100 ms of the first produced a smaller Ca2+ release. The maximum magnitude of the decrease in Ca2+ release was greater in EDL than soleus. Ca2+ release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca2+ released and crossbridge cycles performed are consistent with a scheme in which Ca2+ binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles. PMID:23027818

  18. Selective catalytic reduction of NOx with NH3 over iron-cerium-tungsten mixed oxide catalyst prepared by different methods

    NASA Astrophysics Data System (ADS)

    Xiong, Zhi-bo; Liu, Jing; Zhou, Fei; Liu, Dun-yu; Lu, Wei; Jin, Jing; Ding, Shi-fa

    2017-06-01

    A series of magnetic Fe0.85Ce0.10W0.05Oz catalysts were synthesized by three different methods(Co-precipitation(Fe0.85Ce0.10W0.05Oz-CP), Hydrothermal treatment assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-HT) and Microwave irradiation assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-MW)), and the catalytic activity was evaluated for selective catalytic reduction of NO with NH3. The catalyst was characterized by XRD, N2 adsorption-desorption, XPS, H2-TPR and NH3-TPD. Among the tested catalysts, Fe0.85Ce0.10W0.05Oz-MW shows the highest NOx conversion over per gram in unit time with NOx conversion of 60.8% at 350 °C under a high gas hourly space velocity of 1,200,000 ml/(g h). Different from Fe0.85Ce0.10W0.05Oz-CP catalyst, there exists a large of iron oxide crystallite(γ-Fe2O3 and α-Fe2O3) scattered in Fe0.85Ce0.10W0.05Oz catalysts prepared through hydrothermal treatment or microwave irradiation assistant critic acid sol-gel method, and higher iron atomic concentration on their surface. And Fe0.85Ce0.10W0.05Oz-MW shows higher surface absorbed oxygen concentration and better dispersion compared with Fe0.85Ce0.10W0.05Oz-HT catalyst. These features were favorable for the high catalytic performance of NO reduction with NH3 over Fe0.85Ce0.10W0.05Oz-MW catalyst.

  19. The reaction process of the Bi-Sr-Ca-Cu-O system and the forming mechanism of the 2212 superconducting phase

    NASA Astrophysics Data System (ADS)

    Xiong, Guohong; Wang, Minquan; Fan, Xianping; Tang, Xiaoming

    1993-02-01

    The reaction process and the reaction behavior of each component in the Bi-Sr-Ca-Cu-O system are presented in this paper. It reveals that the reaction is carried out in three different stages: forming of an insulating interphase at 680°C 790°C, forming of the 2212 superconducting phase at 790°C 860°C and forming often semiconducting phases in the presence of the liquid phase at 860°C 970°C. It is also confirmed that the 2212 superconducting phase ( T c=85 K) is formed by the reaction of a trinary interphase together with CuO, SrO and CaO. A new two-step method is presented to prepare the 2212 superconducting phase by a presynthesized interphase.

  20. Effect of toluene diisocyanate on homeostasis of intracellular-free calcium in human neuroblastoma SH-SY5Y Cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, P.-S.; Chiung, Y.-M.; Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan

    2006-03-01

    The mechanisms of TDI (2,4-toluene diisocyanate)-induced occupational asthma are not fully established. Previous studies have indicated that TDI induces non-specific bronchial hyperreactivity to methacholine and induces contraction of smooth muscle tissue by activating 'capsaicin-sensitive' nerves resulting asthma. Cytosolic-free calcium ion concentrations ([Ca{sup 2+}]{sub c}) are elevated when either capsaicin acts at vanilloid receptors, or methacholine at muscarinic receptors. This study therefore investigated the effects of TDI on Ca{sup 2+} mobilization in human neuroblastoma SH-SY5Y cells. TDI was found to elevate [Ca{sup 2+}]{sub c} by releasing Ca{sup 2+} from the intracellular stores and extracellular Ca{sup 2+} influx. 500 {mu}M TDI inducedmore » a net [Ca{sup 2+}]{sub c} increase of 112 {+-} 8 and 78 {+-} 6 nM in the presence and absence of extracellular Ca{sup 2+}, respectively. In Ca{sup 2+}-free buffer, TDI induced Ca{sup 2+} release from internal stores to reduce their Ca{sup 2+} content and this reduction was evidenced by a suppression occurring on the [Ca{sup 2+}]{sub c} rise induced by thapsigargin, ionomycin, and methacholine after TDI incubation. In the presence of extracellular Ca{sup 2+}, simultaneous exposure to TDI and methacholine led a higher level of [Ca{sup 2+}]{sub c} compared to single methacholine stimulation, that might explain that TDI induces bronchial hyperreactivity to methacholine. We conclude that TDI is capable of interfering the [Ca{sup 2+}]{sub c} homeostasis including releasing Ca{sup 2+} from internal stores and inducing extracellular Ca{sup 2+} influx. The interaction of this novel character and bronchial hyperreactivity need further investigation.« less

  1. Current statins show calcium channel blocking activity through voltage gated channels.

    PubMed

    Ali, Niaz; Begum, Robina; Faisal, Muhammad Saleh; Khan, Aslam; Nabi, Muhammad; Shehzadi, Gulfam; Ullah, Shakir; Ali, Waqar

    2016-09-21

    Statins are used for treatment of hypercholestremia. Common adverse reports associated with use of statins are generalized bodyache, rhabdomyolysis, muscles weakness and gastrointestinal disorders. The current work is an attempt to explain how smooth muscles of gastrointestinal tissues are affected by the current statins (Simvastatin, atorvastatin, fluvastatin and rosuvastatin). Effects of the current statins were studied on spontaneous activity of isolated rabbits' jejunal preparations. Different molar concentrations (10(-12)-10(-2)M) of the statins were applied on spontaneously contracting rabbits' jejunal preparations. As statins relaxed spontaneous activity, so we tested the statins on KCl (80 mM) induced contractions in similar test concentrations. Positive relaxant statins were tested again through construction of Calcium Concentration Response Curves (CCRCs) in the absence and presence of the statins using verapamil, a standard calcium channel blocker. CCRCs of statins were compared with CCRCs of verapamil. Simvastatin, atorvastatin, fluvastatin and rosuvastatin relaxed the spontaneous and KCl-induced contractions. IC50 for simvastatin on spontaneous rabbit's jejunal preparations is -5.08 ± 0.1 Log 10 M. Similarly, IC50 for KCl-induced contractions is -4.25 ± 0.01 Log 10 M. Mean IC50 (Log 10 M) for atorvastatin on spontaneous rabbit's jejunal preparations and KCl-induced contractions are -5.19 ± 0.07 and -4.37 ± 0.09, respectively. Fluvastatin relaxed spontaneous activity of rabbits' jejunal preparations with an IC50 (Log 10 M) -4.5 ± 0.03. Rosuvastatin relaxed spontaneous as well as KCl (80 mM) induced contractions with respective IC50 (Log 10 M) -3.62 ± 0.04 and -4.57 ± 0.06. In case of CCRCs, tissues pre-treated with 4.6 μg/ml of simvastatin, have IC50 = -1.84 ± 0.03 [log (Ca(++)) M] vs control IC50 = -2.54 ± 0.04 [log (Ca(++)) M]. Similarly, atorvastatin, fluvastatin and rosuvastatin produced significant right shift in IC50 for CCRCs (P ≤ 0.05). In case of verapamil, IC50 for control curves is -2.45 ± 0.06 [log (Ca (++)) M], while IC50 in presence of verapamil (0.1 μM) is -1.69 ± 0.05 [log (Ca (++)) M]. Statins produced right shift in the IC50 of CCRCs. The effects of statins are like that of effects of verapamil, a standard calcium channel blocker. Our findings suggest that current statins have calcium antagonistic effects that act on voltage gated calcium channels that may provide a rationale for cause muscle weakness and gastrointestinal disorders.

  2. Autophosphorylation of CaMKK2 generates autonomous activity that is disrupted by a T85S mutation linked to anxiety and bipolar disorder.

    PubMed

    Scott, John W; Park, Elizabeth; Rodriguiz, Ramona M; Oakhill, Jonathan S; Issa, Samah M A; O'Brien, Matthew T; Dite, Toby A; Langendorf, Christopher G; Wetsel, William C; Means, Anthony R; Kemp, Bruce E

    2015-09-23

    Mutations that reduce expression or give rise to a Thr85Ser (T85S) mutation of Ca(2+)-CaM-dependent protein kinase kinase-2 (CaMKK2) have been implicated in behavioural disorders such as anxiety, bipolar and schizophrenia in humans. Here we report that Thr85 is an autophosphorylation site that endows CaMKK2 with a molecular memory that enables sustained autonomous activation following an initial, transient Ca(2+) signal. Conversely, autophosphorylation of Ser85 in the T85S mutant fails to generate autonomous activity but instead causes a partial loss of CaMKK2 activity. The loss of autonomous activity in the mutant can be rescued by blocking glycogen synthase kinase-3 (GSK3) phosphorylation of CaMKK2 with the anti-mania drug lithium. Furthermore, CaMKK2 null mice representing a loss of function model the human behavioural phenotypes, displaying anxiety and manic-like behavioural disturbances. Our data provide a novel insight into CaMKK2 regulation and its perturbation by a mutation associated with behavioural disorders.

  3. OBJ-1, a Study in Executable Algebraic Formal Specification.

    DTIC Science & Technology

    1983-09-30

    AD-A136 282 0~ DNEEAA EAGBACOM / SPEC CAION(U) SRI INTERNATIONAL MENL0 PARK CA 30 SEP 83 NOON 4-83- C 0333 UNCLASSIFIED A/ 9/2 NL.mE.. liii102. 8...Contract No. N00014-83- C -0333 Subject: Progress Report for Fiscal Year 1983 Dear Dr. Grafton: Enclosed is one copy of our technical progress report on our...Unlimited 313 Ravenswood Ave e Menlo Park. CA94025 0 415 326-620) e flWX 010-373-1246 • TELEX 3,463 * Facsimilp 415 32f-5512 ~3 / C /A% ., A cceSionFor L T

  4. Semiconductor Alloy Theory.

    DTIC Science & Technology

    1985-09-27

    REPORT & PERIOD COVERED -v Semiconductor Alloy Theory Annual 0) 84-9-1 to 85-8-31 M’) 6. PERFORMING O𔃾G. REPORT NUMBER 7. AUTHOR(@) 8. CONTRACT OR...GRANT NUMBER(s) An-Ban Chen AFOSR-84-0282 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK AREA & W R UNT NUMBERS Auburn...and the effective mass. We generalized the formula for indirect-gap alloys with multiple bands and applied it to SiGe alloy. Our results, correlated

  5. Development of Fracture Mechanics Maps for Composite Materials. Volume 1.

    DTIC Science & Technology

    1985-12-01

    A________________________ N 4. PERFORMING ORGANIZATION REPORT NUMBER (S) 5. MONITORING ORGANIZATION REPORT NUMBER (S) None AFWAL-TR-85-4150, Vol 1 6. NAME OF ... OF FUNDING/SPONSORING Sb. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION if appplicable) European Space Technology Comm...ttee N/A ESTEC/ Contract No 4825/81/ML/AK(SC) B:. ADDRESS (City. State a=d ZIP Codel 10. SOURCE OF FUNDING NOS. ROG RAM’ PR OJE CT TASK WORK UNIT

  6. Activation of p42/p44 mitogen-activated protein kinase and contraction by prostaglandin F2alpha, ionomycin, and thapsigargin in cat iris sphincter smooth muscle: inhibition by PD98059, KN-93, and isoproterenol.

    PubMed

    Ansari, H R; Husain, S; Abdel-Latif, A A

    2001-10-01

    In the present study we investigated the cross talk between the Ca2+ mobilization pathway and the mitogen-activated protein (MAP) kinase pathway and contraction in the cat iris sphincter smooth muscle. Three Ca2+-mobilizing agonists, namely, prostaglandin F2alpha (PGF2alpha), ionomycin, and thapsigargin, and three specific inhibitors, PD98059, a p42/p44 MAP kinase inhibitor; KN-93, a Ca2+-calmodulin-dependent protein kinase II (CaMKII) blocker; and isoproterenol, a cAMP-elevating agent, were used. Changes in tension in response to the agonists were recorded isometrically and MAP kinase phosphorylation and activation were monitored by Western blotting and by in situ myelin basic protein phosphorylation, respectively. We found that 1) stimulation of the sphincter muscle with PGF2alpha, ionomycin, or thapsigargin resulted in rapid phosphorylation and activation of p42/p44 MAP kinase and contraction; and 2) treatment of the muscles with PD98059, KN-93, or isoproterenol resulted in inhibition of the Ca2+-mobilizing agonist-induced responses. The contractile responses induced by PGF2alpha, ionomycin, and thapsigargin were (mg of tension/mg of wet weight tissue) 15.2, 15.4, and 16.2, respectively; the increases in MAP kinase phosphorylation by these agonists were 228, 203, and 190%, respectively; and the increases in MAP kinase activation by the agonists were 212, 191, and 162%, respectively. The stimulatory effects of the agonists on contraction and on MAP kinase phosphorylation and activation were blocked by preincubation of the muscle with PD98059, KN-93, or isoproterenol. These data demonstrate that in the iris sphincter phosphorylation and activation of p42/p44 MAP kinases by PGF2alpha, ionomycin, or thapsigargin require intracellular Ca2+ either from extracellular sources or from internal stores, that CaMKII plays an important role in the regulation of contraction, that CaMKII acts upstream of MAP kinase to control its activation, and that the MAP kinase signaling pathway can play a significant role in mediating the cellular effects of these Ca2+-mobilizing agonists.

  7. Low-frequency oscillations of the neural drive to the muscle are increased with experimental muscle pain

    PubMed Central

    Negro, Francesco; Gizzi, Leonardo; Falla, Deborah

    2012-01-01

    We investigated the influence of nociceptive stimulation on the accuracy of task execution and motor unit spike trains during low-force isometric contractions. Muscle pain was induced by infusion of hypertonic saline into the abductor digiti minimi muscle of 11 healthy men. Intramuscular EMG signals were recorded from the same muscle during four isometric contractions of 60-s duration at 10% of the maximal force [maximal voluntary contraction (MVC)] performed before injection (baseline), after injection of isotonic (control) or hypertonic saline (pain), and 15 min after pain was no longer reported. Each contraction was preceded by three 3-s ramp contractions from 0% to 10% MVC. The low-frequency oscillations of motor unit spike trains were analyzed by the first principal component of the low-pass filtered spike trains [first common component (FCC)], which represents the effective neural drive to the muscle. Pain decreased the accuracy of task performance [coefficient of variation (CoV) for force: baseline, 2.8 ± 1.8%, pain, 3.9 ± 1.8%; P < 0.05] and reduced motor unit discharge rates [11.6 ± 2.3 pulses per second (pps) vs. 10.7 ± 1.7 pps; P < 0.05]. Motor unit recruitment thresholds (2.2 ± 1.2% MVC vs. 2.4 ± 1.6% MVC), interspike interval variability (18.4 ± 4.9% vs. 19.1 ± 5.4%), strength of motor unit short-term synchronization [common input strength (CIS) 1.02 ± 0.44 vs. 0.83 ± 0.22], and strength of common drive (0.47 ± 0.08 vs. 0.47 ± 0.06) did not change across conditions. The FCC signal was correlated with force (R = 0.45 ± 0.06), and the CoV for FCC increased in the painful condition (5.69 ± 1.29% vs. 7.83 ± 2.61%; P < 0.05). These results indicate that nociceptive stimulation increased the low-frequency variability in synaptic input to motoneurons. PMID:22049336

  8. Structural, microstructural, dielectric and ferroelectric properties of lead free Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramic

    NASA Astrophysics Data System (ADS)

    Sharma, Sarita; Sharma, Hakikat; Negi, N. S.

    2018-05-01

    Lead free Ba0.85Ca0.15Zr0.1Ti0.9O3(BCTZ) ceramic has been synthesized by sol-gel method. Properties of material are studied at different sintering temperatures for 5 hours. Structural and microstructural properties are analyzed by using X-ray diffractrometer (XRD) and scanning electron microscopy (SEM) at annealing temperature of 850°C and 1050°C XRD pattern confirm the perovskite structure of the material without any unwanted phases crystalinity increased with increase of sintering temperature so as roughness and porosity is decreased as shown by SEM micrographs. There is large improvement in density with rise of sintering temperature which also leads to drastic change in ferroelectric and dielectric properties.

  9. Analyses of a Gravistimulation-Specific Ca2+ Signature in Arabidopsis using Parabolic Flights1[W][OPEN

    PubMed Central

    Toyota, Masatsugu; Furuichi, Takuya; Sokabe, Masahiro; Tatsumi, Hitoshi

    2013-01-01

    Gravity is a critical environmental factor affecting the morphology and functions of organisms on the Earth. Plants sense changes in the gravity vector (gravistimulation) and regulate their growth direction accordingly. In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation, achieved by rotating the specimens under the ambient 1g of the Earth, is known to induce a biphasic (transient and sustained) increase in cytoplasmic calcium concentration ([Ca2+]c). However, the [Ca2+]c increase genuinely caused by gravistimulation has not been identified because gravistimulation is generally accompanied by rotation of specimens on the ground (1g), adding an additional mechanical signal to the treatment. Here, we demonstrate a gravistimulation-specific Ca2+ response in Arabidopsis seedlings by separating rotation from gravistimulation by using the microgravity (less than 10−4g) conditions provided by parabolic flights. Gravistimulation without rotating the specimen caused a sustained [Ca2+]c increase, which corresponds closely to the second sustained [Ca2+]c increase observed in ground experiments. The [Ca2+]c increases were analyzed under a variety of gravity intensities (e.g. 0.5g, 1.5g, or 2g) combined with rapid switching between hypergravity and microgravity, demonstrating that Arabidopsis seedlings possess a very rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes (0.5g–2g) into Ca2+ signals on a subsecond time scale. PMID:23835410

  10. Analyses of a gravistimulation-specific Ca2+ signature in Arabidopsis using parabolic flights.

    PubMed

    Toyota, Masatsugu; Furuichi, Takuya; Sokabe, Masahiro; Tatsumi, Hitoshi

    2013-10-01

    Gravity is a critical environmental factor affecting the morphology and functions of organisms on the Earth. Plants sense changes in the gravity vector (gravistimulation) and regulate their growth direction accordingly. In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation, achieved by rotating the specimens under the ambient 1g of the Earth, is known to induce a biphasic (transient and sustained) increase in cytoplasmic calcium concentration ([Ca(2+)]c). However, the [Ca(2+)]c increase genuinely caused by gravistimulation has not been identified because gravistimulation is generally accompanied by rotation of specimens on the ground (1g), adding an additional mechanical signal to the treatment. Here, we demonstrate a gravistimulation-specific Ca(2+) response in Arabidopsis seedlings by separating rotation from gravistimulation by using the microgravity (less than 10(-4)g) conditions provided by parabolic flights. Gravistimulation without rotating the specimen caused a sustained [Ca(2+)]c increase, which corresponds closely to the second sustained [Ca(2+)]c increase observed in ground experiments. The [Ca(2+)]c increases were analyzed under a variety of gravity intensities (e.g. 0.5g, 1.5g, or 2g) combined with rapid switching between hypergravity and microgravity, demonstrating that Arabidopsis seedlings possess a very rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes (0.5g-2g) into Ca(2+) signals on a subsecond time scale.

  11. Calcium triggers reversal of calmodulin on nested anti-parallel sites in the IQ motif of the neuronal voltage-dependent sodium channel NaV1.2.

    PubMed

    Hovey, Liam; Fowler, C Andrew; Mahling, Ryan; Lin, Zesen; Miller, Mark Stephen; Marx, Dagan C; Yoder, Jesse B; Kim, Elaine H; Tefft, Kristin M; Waite, Brett C; Feldkamp, Michael D; Yu, Liping; Shea, Madeline A

    2017-05-01

    Several members of the voltage-gated sodium channel family are regulated by calmodulin (CaM) and ionic calcium. The neuronal voltage-gated sodium channel Na V 1.2 contains binding sites for both apo (calcium-depleted) and calcium-saturated CaM. We have determined equilibrium dissociation constants for rat Na V 1.2 IQ motif [IQRAYRRYLLK] binding to apo CaM (~3nM) and (Ca 2+ ) 4 -CaM (~85nM), showing that apo CaM binding is favored by 30-fold. For both apo and (Ca 2+ ) 4 -CaM, NMR demonstrated that Na V 1.2 IQ motif peptide (Na V 1.2 IQp ) exclusively made contacts with C-domain residues of CaM (CaM C ). To understand how calcium triggers conformational change at the CaM-IQ interface, we determined a solution structure (2M5E.pdb) of (Ca 2+ ) 2 -CaM C bound to Na V 1.2 IQp . The polarity of (Ca 2+ ) 2 -CaM C relative to the IQ motif was opposite to that seen in apo CaM C -Na v 1.2 IQp (2KXW), revealing that CaM C recognizes nested, anti-parallel sites in Na v 1.2 IQp . Reversal of CaM may require transient release from the IQ motif during calcium binding, and facilitate a re-orientation of CaM N allowing interactions with non-IQ Na V 1.2 residues or auxiliary regulatory proteins interacting in the vicinity of the IQ motif. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Effect of dietary calcium and phosphorus levels on the total tract digestibility of innate and supplemental organic and inorganic microminerals in a corn-soybean meal based diet of grower pigs.

    PubMed

    Jolliff, J S; Mahan, D C

    2013-06-01

    The effects of Ca and P (CaP) levels and micromineral sources on mineral digestibility were evaluated in growing pigs. Treatments consisted of 2 levels of CaP and 3 trace mineral (TM) treatments arranged as a 2 × 3 factorial in a randomized complete block design with 8 replicates. The CaP levels evaluated were: 1) 0.65% Ca and 0.55% P [standard CaP (Std CaP)], and 2) 1.00% Ca and 0.85% P (High CaP). The TM treatments were: 1) Basal, without supplemental TM, 2) Basal supplemented with organic TM, and 3) Basal supplemented with inorganic TM. Both organic and inorganic TM premixes added 15 mg Cu, 150 mg Fe, 10 mg Mn, 0.3 mg Se, and 140 mg Zn/kg diet. Diets were formulated using corn soybean meal with a Ca to P ratio of 1.18 in both CaP treatments. Barrows with an initial BW of 45 kg were acclimated to stainless steel metabolism crates where diets were fed for 14 d before a 10-d collection period. Pigs within replicates were fed equivalent amounts of feed at 0800 and 1600 h each day with water provided free choice. Total feces, urine, and feed orts were collected daily. Essential macro- and microminerals were analyzed by inductively coupled plasma analysis. Increasing dietary CaP decreased the digestibility of Ca and Zn. Phosphorus digestibility did not change when the P inclusion level increased from 0.55 to 0.85% Ptotal. The High CaP level resulted in a lower urinary excretion of most minerals, particularly Cu (P < 0.05) and Mn (P < 0.05), as dietary CaP level increased but the others were not statistically significant. A summary of the ATTD for each of the experimental variables was statistically analyzed and averaged for the experiment. Although there were few statistical differences with individual minerals, they generally demonstrated a decline in digestibility when the High CaP was fed, averaging a 3% lower digestibility consistently than when the Std CaP level was fed. Organic TM averaged an approximately 5% greater digestibility than the average inorganic microminerals with the difference between minerals within each source relatively consistent. These results indicate that CaP level had the greatest effect on mineral digestibility, organic microminerals had a greater digestibility than inorganic minerals, and the innate microminerals had an average apparent digestibility of 45%.

  13. NESTOR: A Computer-Based Medical Diagnostic Aid That Integrates Causal and Probabilistic Knowledge.

    DTIC Science & Technology

    1984-11-01

    indiidual conditional probabilities between one cause node and its effect node, but less common to know a joint conditional probability between a...PERFOAMING ORG. REPORT NUMBER * 7. AUTI4ORs) O Gregory F. Cooper 1 CONTRACT OR GRANT NUMBERIa) ONR N00014-81-K-0004 g PERFORMING ORGANIZATION NAME AND...ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK Department of Computer Science AREA & WORK UNIT NUMBERS Stanford University Stanford, CA 94305 USA 12. REPORT

  14. Microscopic heat pulses induce contraction of cardiomyocytes without calcium transients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Oyama, Kotaro; Mizuno, Akari; Shintani, Seine A.

    Highlights: Black-Right-Pointing-Pointer Infra-red laser beam generates microscopic heat pulses. Black-Right-Pointing-Pointer Heat pulses induce contraction of cardiomyocytes. Black-Right-Pointing-Pointer Ca{sup 2+} transients during the contraction were not detected. Black-Right-Pointing-Pointer Skinned cardiomyocytes in free Ca{sup 2+} solution also contracted. Black-Right-Pointing-Pointer Heat pulses regulated the contractions without Ca{sup 2+} dynamics. -- Abstract: It was recently demonstrated that laser irradiation can control the beating of cardiomyocytes and hearts, however, the precise mechanism remains to be clarified. Among the effects induced by laser irradiation on biological tissues, temperature change is one possible effect which can alter physiological functions. Therefore, we investigated the mechanism by which heatmore » pulses, produced by infra-red laser light under an optical microscope, induce contractions of cardiomyocytes. Here we show that microscopic heat pulses induce contraction of rat adult cardiomyocytes. The temperature increase, {Delta}T, required for inducing contraction of cardiomyocytes was dependent upon the ambient temperature; that is, {Delta}T at physiological temperature was lower than that at room temperature. Ca{sup 2+} transients, which are usually coupled to contraction, were not detected. We confirmed that the contractions of skinned cardiomyocytes were induced by the heat pulses even in free Ca{sup 2+} solution. This heat pulse-induced Ca{sup 2+}-decoupled contraction technique has the potential to stimulate heart and skeletal muscles in a manner different from the conventional electrical stimulations.« less

  15. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2015-04-15

    0 A S S PROGRESS REPORT NO. QSR-14C0172-0CEAN ACOUSTICS-033115 Contract No. N00014-14-C-0172 Office of Naval Research Task Reporting: Deep ...AND SUBTITLE Deep Water Ocean Acoustics 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Cost Summary OASIS, INC. JOB STATUS RB’ORT 1172 DEEP WATER ACOUSTICS FOP. 9/27f13-316/16

  16. Aminophylline preferentially inhibits chloroethylclonidine-insensitive alpha-adrenoceptor-mediated contractions in rat aorta.

    PubMed

    Duarte, J; Pérez-Vizcaíno, F; Zarzuelo, A; Jiménez, J; Tamargo, J

    1993-11-01

    1. In rat thoracic aortae, contractions induced by methoxamine were inhibited by chloroethylclonidine, whereas oxymetazoline-induced contractions, which were more dependent on Ca(2+)-entry, were insensitive to chloroethylclonidine. 2. Aminophylline inhibited the contractions and 45Ca(2+)-uptake induced by both methoxamine and oxymetazoline. However, oxymetazoline-induced contractions were more sensitive to inhibition by aminophylline and D600. 3. Thus, the partial selectivity of aminophylline for the chloroethylclonidine-resistant, highly dependent on extracellular Ca2+, oxymetazoline-mediated responses may be explained by a preferential inhibition of agonist-induced Ca2+ entry as compared to inhibition of other transduction pathways.

  17. X-ray diffraction and spectroscopic study of wiluite: implications for the vesuvianite-group nomenclature

    NASA Astrophysics Data System (ADS)

    Panikorovskii, Taras L.; Mazur, Anton S.; Bazai, Ayya V.; Shilovskikh, Vladimir V.; Galuskin, Evgeny V.; Chukanov, Nikita V.; Rusakov, Vyacheslav S.; Zhukov, Yurii M.; Avdontseva, Evgenia Yu.; Aksenov, Sergey M.; Krivovichev, Sergey V.

    2017-09-01

    Two wiluite samples from the Wiluy River, Yakutia, Russia have been investigated by means of single-crystal and powder X-ray diffraction, electron microprobe analysis, 1H, 27Al, 11B, and 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (DSC/TGA), X-ray photoelectron spectroscopy (XPS) at the Si2p, Ca2p, Al2p, Mg1s, B1s and Fe2p core levels, 57Fe Mössbauer spectroscopy, infrared (IR) spectroscopy and optical measurements. The crystal structures have been refined in the P4/ nnc space group [ a = 15.7027(3), c = 11.7008(3) Å, V = 2885.1(1) Å3 for 1 and a = 15.6950(2), c = 11.6787(4) Å, V = 2876.9(1) Å3 for 2] to R 1 = 0.022 and R 1 = 0.021, respectively. In the crystal structure of wiluite, five-coordinated Y1 site is predominantly occupied by Mg. IR spectra of wiluite substantially different from those of vesuvianite, in particular, by the presence of additional bands in the range 1080‒1415 cm-1, which correspond to symmetric B‒O stretching vibrations of the BO 3 3- and BO 4 5- groups. According to the MAS NMR data, tetrahedrally coordinated T1 site is occupied by B3+ with minor amounts of Al3+. The general formula of wiluite can be written as follows ( Z = 2): Ca19Mg(Al,Mg,Fe,Ti,Mn)12(B,Al,◻)5(Si2O7)4(SiO4)10(O,OH)9O2-3. The diversity of vesuvianite-group minerals is largely determined by the population of the Y1 sites. However, wiluite is characterized by the presence of additional T1 and T2 sites and should be considered as special among other vesuvianite-group minerals. The reasonability of subdivision of the wiluite subgroup within the vesuvianite group is discussed.

  18. Phosphate glass useful in high energy lasers

    DOEpatents

    Hayden, Y.T.; Guesto-Barnak, D.

    1992-12-22

    Disclosed is a low-or no-silica, low- or no-alkali phosphate glass useful as a laser amplifier in a multiple pass, high energy laser system having a high thermal conductivity, K[sub 90 C] >0.85 W/mK, a low coefficient of thermal expansion, [alpha][sub 20-300 C] <80[times]10[sup [minus]7]/C, low emission cross section, [sigma]<2.5[times]10[sup [minus]20] cm[sup 2], and a high fluorescence lifetime, [tau]>325 [mu]secs at 3 wt. % Nd doping, consisting essentially of (on an oxide composition basis): (Mole %) P[sub 2]O[sub 5], (52-72); Al[sub 2]O[sub 3], (0-<20); B[sub 2]O[sub 3], (>0-25); ZnO, (0-31); Li[sub 2]O, (0-5); K[sub 2]O, (0-5); Na[sub 2]O, (0-5); Cs[sub 2]O, (0-5); Rb[sub 2]O, (0-5); MgO, (>0-<30); CaO, (0-20); BaO, (0-20); SrO, (0-<20); Sb[sub 2]O[sub 3], (0-<1); As[sub 2]O[sub 3], (0-<1); Nb[sub 2]O[sub 5], (0-<1); Ln[sub 2]O[sub 3], (up to 6.5); PbO, (0-<5); and SiO[sub 2], (0-3); wherein Ln[sub 2]O[sub 3] is the sum of lanthanide oxides; [Sigma]R[sub 2]O is <5, R being Li, Na, K, Cs, and Rb; the sum of Al[sub 2]O[sub 3] and MgO is <24 unless [Sigma]R[sub 2]O is 0, then the sum of Al[sub 2]O[sub 3] and MgO is <42; and the ratio of MgO to B[sub 2]O[sub 3] is 0.48-4.20. 7 figs.

  19. 34 CFR 85.220 - Are any procurement contracts included as covered transactions?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Are any procurement contracts included as covered... DEBARMENT AND SUSPENSION (NONPROCUREMENT) Covered Transactions § 85.220 Are any procurement contracts... procurement contracts awarded directly by a Federal agency; but (2) Do include some procurement contracts...

  20. Structural and electrical properties of 1 − x(Na{sub 0.5}K{sub 0.5})NbO{sub 3}–x(Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} ceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Tae-Ho; Lee, Sung-Gap, E-mail: lsgap@gnu.ac.kr; Yeo, Jin-Ho

    2014-10-15

    Highlights: • We fabricated lead-free (Na{sub 0.5}K{sub 0.5})NbO{sub 3} ceramics. • We studied the structural and electrical properties of 1 − x(Na{sub 0.5}K{sub 0.5})NbO{sub 3}–x(Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} ceramics. • The structural and electrical properties improved with increasing amount of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3}. - Abstract: In this study, 1 − x(Na{sub 0.5}K{sub 0.5})NbO{sub 3}–x(Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} ceramics were fabricated using the conventional mixed oxide method. The effects of the addition of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} on the structural and electrical properties of the specimens were investigated for their application in piezoelectric devices. As the results of X-ray diffractionmore » analysis show, all specimens display the typical polycrystalline perovskite structure without the presence of the second phase. Sintered densities increased with an increase in the amount of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} added and the specimen with 0.08 mol% of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} added showed the maximum value of 4.54 g/cm{sup 3}. Both average grain size and densification increased with an increase in the amount of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3}. The electromechanical coupling factor, dielectric constant ϵ{sub r}, dielectric loss tan δ, d{sub 33} and Curie temperature of the 0.92(Na{sub 0.5}K{sub 0.5})NbO{sub 3}–0.08(Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} specimens doped with 0.08 mol% of (Sr{sub 0.5}Ca{sub 0.5})TiO{sub 3} were 0.31, 1338, 0.021, 138 and 445 °C, respectively.« less

  1. CaMKII activity is essential for improvement of memory-related behaviors by chronic rivastigmine treatment.

    PubMed

    Moriguchi, Shigeki; Tagashira, Hideaki; Sasaki, Yuzuru; Yeh, Jay Z; Sakagami, Hiroyuki; Narahashi, Toshio; Fukunaga, Kohji

    2014-03-01

    Because the cholinergic system is down-regulated in the brain of Alzheimer's disease patients, cognitive deficits in Alzheimer's disease patients are significantly improved by rivastigmine treatment. To address the mechanism underlying rivastigmine-induced memory improvements, we chronically treated olfactory bulbectomized (OBX) mice with rivastigmine. The chronic rivastigmine treatments for 12-13 days starting at 10 days after OBX operation significantly improved memory-related behaviors assessed by Y-maze task, novel object recognition task, passive avoidance task, and Barnes maze task, whereas the single rivastigmine treatment failed to improve the memory. Consistent with the improved memory-related behaviors, long-term potentiation in the hippocampal CA1 region was markedly restored by rivastigmine treatments. In immunoblotting analyses, the reductions of calcium/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation and calcium/calmodulin-dependent protein kinase IV (CaMKIV) phosphorylation in the CA1 region in OBX mice were significantly restored by rivastigmine treatments. In addition, phosphorylation of AMPAR subunit glutamate receptor 1 (GluA1) (Ser-831) and cAMP-responsive element-binding protein (Ser-133) as downstream targets of CaMKII and CaMKIV, respectively, in the CA1 region was also significantly restored by chronic rivastigmine treatments. Finally, we confirmed that rivastigmine-induced improvements of memory-related behaviors and long-term potentiation were not obtained in CaMKIIα(+/-) mice. On the other hand, CaMKIV(-/-) mice did not exhibit the cognitive impairments. Taken together, the stimulation of CaMKII activity in the hippocampus is essential for rivastigmine-induced memory improvement in OBX mice. © 2013 International Society for Neurochemistry.

  2. Study on Dy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ-Ce0.85Gd0.15O1.95 composite cathode material for intermediate temperature solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Kautkar, Pranay R.; Acharya, Smita A.

    2018-05-01

    xDy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ - xCe0.85Gd0.15O1.95 (x = 50 %) composite cathode supported on Ce0.85Gd0.15O1.95 (GDC15) electrolyte are studied for applications in IT-SOFCs. Results attribute that Dy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ material is chemically compatible with Ce0.85Gd0.15O1.95 (GDC15). Rietveld refined X-ray diffraction patterns notify orthorhombic (space group:Pbnm) symmetry for Dy0.45 Ba0.05Sr0.5Co0.8Fe0.2O3-δ and fluorite type structure (space group: Fm-3m) symmetry for GDC15. The polarization resistance (Rp) of composite cathode reduces to the minimum value of 1.35 Ω cm2 at 650 °C in air. Area specific resistance (ASR) of composite cathode has found 0.67 Ω.cm2 at 650°C respectively. Result shows that the surface diffusion of the dissociative adsorbed oxygen at electrode/electrolyte interface on the composite cathode.

  3. Support of the Laboratory for Terrestrial Physics for Dynamics of the Solid Earth (DOSE)

    NASA Technical Reports Server (NTRS)

    Vandenberg, Nancy R.; Ma, C. (Technical Monitor)

    2001-01-01

    This final report summarizes the accomplishments during the contract period. Under the contract NVI, Inc. provided support to the VLBI group at NASA's Goddard Space Flight Center. The contract covered a period of approximately eight years during which geodetic and astrometric VLBI evolved through several major changes. This report is divided into four sections which correspond to major task areas in the contract: A) Coordination and Scheduling, B) Field System, C) Station Support, and D) Analysis and Research and Development.

  4. Support for the Laboratory for Terrestrial Physics for Dynamics of the Solid Earth (DOSE)

    NASA Technical Reports Server (NTRS)

    Ma, C. (Technical Monitor)

    2001-01-01

    This final report summarizes the accomplishments during the contract period. Under the contract NVI, Inc. provided support to the VLBI group at NASA's Goddard Space Flight Center. The contract covered a period of approximately eight years during which geodetic and astrometric VLBI evolved through several major changes. This report is divided into four sections which correspond to major task areas in the contract: A) Coordination and Scheduling, B) Field System, C) Station Support, and D) Analysis and Research and Development.

  5. Cost/Risk Analysis for Disk Retirement. Volume 1

    DTIC Science & Technology

    1984-02-03

    comparing Figures 4-4, 4-5, and 4- 6 , which is similar for the other 4-8 co C)) 0 - 6 row L. 0ý ci 41C~j <o u ) 4.-1 LG)) a)L I- . > c- Ca 0. 4-)>C ~.0...4-1 M&T3B-9201 7. AUT’l)R(a) 6 . CONTRACT OR GRANT NUMBER(&) S. W. Hopkins, P. M. Besuner, C. A. Eau, Jr.., D. W. Allison, J. W. Eischeni, J. N...Analysis Associates 2225 East Bayshore Road, P. 0. Box 51470 PE 61102F * Palo Al%’o. CA 94303 3400 00 01 I I. CONTROLLING OFFICE NAME AND ADDRESS t2. REPORT

  6. Alu–based cell-free DNA: a novel biomarker for screening of gastric cancer

    PubMed Central

    Zhao, Jianmei; Shen, Xianjuan; Jing, Rongrong; Yu, Juan; Li, Li; Shi, Yingjuan; Zhang, Lurong; Wang, Zhiwei; Cong, Hui

    2017-01-01

    Gastric cancer (GC) is the fourth most common cancer and the second major cause of cancer-related deaths worldwide. In our previous study, a novel and sensitive method for quantifying cell-free DNA (CFD) in human blood was established and tested for its ability to predict patients with tumor. We want to investigate CFD expression in the sera of GC patients in an attempt to explore the clinical significance of CFD in improving the early screening of GC and monitoring GC progression by the branched DNA (bDNA)-based Alu assay. The concentration of CFD was quantitated by bDNA-based Alu assay. CEA, CA19-9, C72-4 and CA50 concentrations were determined by ABBOTT ARCHITECT I2000 SR. We found the CFD concentrations have significant differences between GC patients, benign gastric disease (BGD) patients and healthy controls (P < 0.05). CFD were weakly correlated with CEA (r = −0.197, P < 0.05) or CA50 (r = 0.206, P < 0.05), and no correlation with CA19-9 (r = −0.061, P > 0.05) or CA72-4 (r = 0.011, P > 0.05). In addition, CFD concentrations were significantly higher in stage I GC patients than BGD patients and healthy controls (P < 0.05), but there was no significant difference in CEA, CA19-9 and CA50 among the three traditional tumor markers (P > 0.05). Our analysis showed that CFD was more sensitive than CEA, CA19-9, CA72-4 or CA50 in early screening of GC. Compared with CEA, CA19-9, CA72-4 and CA50, CFD may prove to be a better biomarker for the screening of GC, thus providing a sensitive biomarker for screening and monitoring progression of GC. PMID:28903321

  7. [Fluorine removal efficiency of organic-calcium during coal combustion].

    PubMed

    Liu, Jing; Liu, Jian-Zhong; Zhou, Jun-Hu; Xiao, Hai-Ping; Cen, Ke-Fa

    2006-08-01

    Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.

  8. The impact of extracellular and intracellular Ca2+ on ethanol-induced smooth muscle contraction.

    PubMed

    Döndaş, Naciye Yaktubay; Kaplan, Mahir; Kaya, Derya; Singirik, Ergin

    2009-10-01

    To evaluate the impact of extracellular and intracellular Ca2+ on contractions induced by ethanol in smooth muscle. Longitudinal smooth muscle strips were prepared from the gastric fundi of mice. The contractions of smooth muscle strips were recorded with an isometric force displacement transducer. Ethanol (164 mmol/L) produced reproducible contractions in isolated gastric fundal strips of mice. Although lidocaine (50 and 100 micromol/L), a local anesthetic agent, and hexamethonium (100 and 500 micromol/L), a ganglionic blocking agent, failed to affect these contractions, verapamil (1-50 micromol/L) and nifedipine (1-50 micromol/L), selective blockers of L-type Ca2+ channels, significantly inhibited the contractile responses of ethanol. Using a Ca(2+)-free medium nearly eliminated these contractions in the same tissue. Ryanodine (1-50 micromol/L) and ruthenium red (10-100 micromol/L), selective blockers of intracellular Ca2+ channels/ryanodine receptors; cyclopiazonic acid (CPA; 1-10 mumol/L), a selective inhibitor of sarcoplasmic reticulum (SR) Ca(2+)-ATPase; and caffeine (0.5-5 mmol/L), a depleting agent of intracellular Ca2+ stores, significantly inhibited the contractile responses induced by ethanol. In addition, the combination of caffeine (5 mmol/L) plus CPA (10 micromol/L), and ryanodine (10 micromol/L) plus CPA (10 micromol/L), caused further inhibition of contractions in response to ethanol. This inhibition was significantly different from those associated with caffeine, ryanodine or CPA. Furthermore the combination of caffeine (5 mmol/L), ryanodine (10 micromol/L) and CPA(10 micromol/L) eliminated the contractions induced by ethanol in isolated gastric fundal strips of mice. Both extracellular and intracellular Ca2+ may have important roles in regulating contractions induced by ethanol in the mouse gastric fundus.

  9. The Post-Award Costs of Contracting Out: The U.S. Navy’s Implementation of OMB Circular A-76

    DTIC Science & Technology

    1988-06-01

    Commercial Activities (CA) Program Update, 6 April 1987. 4. Horngren , C.T. and Foster, G., Cost Accounting : A Managerial Emphasis, 6th Ed., Prentice-Hall... COSTS OF CONTRACTING OUT: THE U.S. NAVY’S IMPLEMENTATION OF OMB CIRCULAR A-76 12 PERSONAL AUTHOR( S ) Cole. Nancy S . and Cnlp Charla P 13a TYPE OF...of contracting out and identifies those costs that are either underestimated or not accounted for in the cost comparison process. Research was

  10. Using Cognitive Task Analysis and Eye Tracking to Understand Imagery Analysis

    DTIC Science & Technology

    2006-01-01

    Using Cognitive Task Analysis and Eye Tracking to Understand Imagery Analysis Laura Kurland, Abigail Gertner, Tom Bartee, Michael Chisholm and...have used these to study the analysts search behavior in detail. 2 EXPERIMENT Using a Cognitive Task Analysis (CTA) framework for knowledge...TITLE AND SUBTITLE Using Cognitive Task Analysis and Eye Tracking to Understand Imagery Analysis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  11. 76 FR 75536 - Procurement List; Proposed Addition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-02

    ... listed: Service Service Type/Location: Grounds Maintenance, Beale AFB, CA. NPA: Crossroads Diversified Service, Inc., Sacramento, CA. Contracting Activity: 9th Contracting Squadron, Beale AFB, CA. Patricia...

  12. Effects of Isometric Hand-Grip Muscle Contraction on Young Adults' Free Recall and Recognition Memory.

    PubMed

    Tomporowski, Phillip D; Albrecht, Chelesa; Pendleton, Daniel M

    2017-03-01

    The purpose of this study was to determine if physical arousal produced by isometric hand-dynamometer contraction performed during word-list learning affects young adults' free recall or recognition memory. Twenty-four young adults (12 female; M age  = 22 years) were presented with 4 20-item word lists. Moderate arousal was induced in 12 adults by an initial 30-s maximal hand-dynamometer squeeze with force productions of 50% maximum; low arousal was induced in 12 adults by an initial 1-s maximal dynamometer squeeze with force production of 10% maximum during learning. Memory performances following dual-task conditions experienced during the encoding, consolidation, and recall phases of learning were compared to a single-task control condition during which words were learned in the absence of isometric exercise. Planned contrasts revealed that arousal coinciding with word encoding led to significantly poorer immediate recall, F(1, 23) = 10.13, p < .05, [Formula: see text] = .31, delayed free recall, F(1, 23) = 15.81, p < .05, [Formula: see text] = .41, and recognition memory, F(1, 23) = 6.07, p < .05, [Formula: see text] = .21, compared with when there was no arousal. Neither arousal condition facilitated participants' memory performance. The reduction in long-term memory performance specific to the encoding phase of learning is explained in terms of the dual-task attentional demands placed on participants.

  13. Transformations of Heavy Metals and Plant Nutrients in Dredged Sediments as Affected by Oxidation Reduction Potential and pH. Volume 2. Materials and Methods/Results and Discussion

    DTIC Science & Technology

    1977-05-01

    D )EGED IATWRAL WI0, 00 EEACHPRGAFT4- CONTRACT REPORT D -77-4 TRANSFORMATIONS OF HEAVY METALS AND PLANT NUTRIENTS IN DREDGED SEDIMENTS AS AFFECTED BY...Engineers, U. S. Army C=) Washington, D . C. 20314 Q-2 Under Contract No. DACW39-74-C-0076 CM-1 (DMRP Work Unit No. IC05) Monitored by Environmental...Sa70mB COMPLETING FOM T -IMPORT PUNIeRf oTACSINN ESCTLGNME Contract Report D -77-4GOTACSINN C NTSAAOGUMR RAAN SFORATIONS OFPEAV71ETALS AND

  14. A novel mammal-specific three partite enhancer element regulates node and notochord-specific Noto expression.

    PubMed

    Alten, Leonie; Schuster-Gossler, Karin; Eichenlaub, Michael P; Wittbrodt, Beate; Wittbrodt, Joachim; Gossler, Achim

    2012-01-01

    The vertebrate organizer and notochord have conserved, essential functions for embryonic development and patterning. The restricted expression of developmental regulators in these tissues is directed by specific cis-regulatory modules (CRMs) whose sequence conservation varies considerably. Some CRMs have been conserved throughout vertebrates and likely represent ancestral regulatory networks, while others have diverged beyond recognition but still function over a wide evolutionary range. Here we identify and characterize a mammalian-specific CRM required for node and notochord specific (NNC) expression of NOTO, a transcription factor essential for node morphogenesis, nodal cilia movement and establishment of laterality in mouse. A 523 bp enhancer region (NOCE) upstream the Noto promoter was necessary and sufficient for NNC expression from the endogenous Noto locus. Three subregions in NOCE together mediated full activity in vivo. Binding sites for known transcription factors in NOCE were functional in vitro but dispensable for NOCE activity in vivo. A FOXA2 site in combination with a novel motif was necessary for NOCE activity in vivo. Strikingly, syntenic regions in non-mammalian vertebrates showed no recognizable sequence similarities. In contrast to its activity in mouse NOCE did not drive NNC expression in transgenic fish. NOCE represents a novel, mammal-specific CRM required for the highly restricted Noto expression in the node and nascent notochord and thus regulates normal node development and function.

  15. Force development and intracellular Ca2+ in intact cardiac muscles from gravin mutant mice.

    PubMed

    Li, Zhitao; Singh, Sonal; Suryavanshi, Santosh V; Ding, Wengang; Shen, Xiaoxu; Wijaya, Cori S; Gao, Wei Dong; McConnell, Bradley K

    2017-07-15

    Gravin (AKAP12) is an A-kinase-anchoring-protein that scaffolds protein kinase A (PKA), β 2 -adrenergic receptor (β 2 -AR), protein phosphatase 2B and protein kinase C. Gravin facilitates β 2 -AR-dependent signal transduction through PKA to modulate cardiac excitation-contraction coupling and its removal positively affects cardiac contraction. Trabeculae from the right ventricles of gravin mutant (gravin-t/t) mice were employed for force determination. Simultaneously, corresponding intracellular Ca 2+ transient ([Ca 2+ ] i ) were measured. Twitch force (T f )-interval relationship, [Ca 2+ ] i -interval relationship, and the rate of decay of post-extrasysolic potentiation (R f ) were also obtained. Western blot analysis were performed to correlate sarcomeric protein expression with alterations in calcium cycling between the WT and gravin-t/t hearts. Gravin-t/t muscles had similar developed force compared to WT muscles despite having lower [Ca 2+ ] i at any given external Ca 2+ concentration ([Ca 2+ ] o ). The time to peak force and peak [Ca 2+ ] i were slower and the time to 75% relaxation was significantly prolonged in gravin-t/t muscles. Both T f -interval and [Ca 2+ ] i -interval relations were depressed in gravin-t/t muscles. R f , however, did not change. Furthermore, Western blot analysis revealed decreased ryanodine receptor (RyR2) phosphorylation in gravin-t/t hearts. Gravin-t/t cardiac muscle exhibits increased force development in responsiveness to Ca 2+ . The Ca 2+ cycling across the SR appears to be unaltered in gravin-t/t muscle. Our study suggests that gravin is an important component of cardiac contraction regulation via increasing myofilament sensitivity to calcium. Further elucidation of the mechanism can provide insights to role of gravin if any in the pathophysiology of impaired contractility. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 77 FR 48135 - Combined Notice of Filings #1

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ...: J.P. Morgan Ventures Energy Corporation, Triton Power Michigan LLC, BE Allegheny LLC, BE CA LLC, BE... Contract Funding, L.L.C., Central Power & Lime LLC, Cedar Brakes II, L.L.C., J.P. Morgan Commodities Canada...; ER10-2898-008. Applicants: J.P. Morgan Ventures Energy Corporation, Triton Power Michigan LLC, BE...

  17. A Mobile, Map-Based Tasking Interface for Human-Robot Interaction

    DTIC Science & Technology

    2010-12-01

    A MOBILE, MAP-BASED TASKING INTERFACE FOR HUMAN-ROBOT INTERACTION By Eli R. Hooten Thesis Submitted to the Faculty of the Graduate School of...SUBTITLE A Mobile, Map-Based Tasking Interface for Human-Robot Interaction 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...3 II.1 Interactive Modalities and Multi-Touch . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 II.2

  18. Comparative studies on troponin, a Ca²⁺-dependent regulator of muscle contraction, in striated and smooth muscles of protochordates.

    PubMed

    Obinata, Takashi; Sato, Naruki

    2012-01-01

    Troponin is well known as a Ca(2+)-dependent regulator of striated muscle contraction and it has been generally accepted that troponin functions as an inhibitor of muscle contraction or actin-myosin interaction at low Ca(2+) concentrations, and Ca(2+) at higher concentrations removes the inhibitory action of troponin. Recently, however, troponin became detectable in non-striated muscles of several invertebrates and in addition, unique troponin that functions as a Ca(2+)-dependent activator of muscle contraction has been detected in protochordate animals, although troponin in vertebrate striated muscle is known as an inhibitor of the contraction in the absence of a Ca(2+). Further studies on troponin in invertebrate muscle, especially in non-striated muscle, would provide new insight into the evolution of regulatory systems for muscle contraction and diverse function of troponin and related proteins. The methodology used for preparation and characterization of functional properties of protochordate striated and smooth muscles will be helpful for further studies of troponin in other invertebrate animals. Copyright © 2011. Published by Elsevier Inc.

  19. On-site characterisation, re-packaging and transport of luminised, former aircraft escape hatches

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reeves, Nigel; John, Gordon; Beadle, Ian

    2007-07-01

    AMEC NNC, under contract to the UK Environment Agency, recovered a number of redundant aircraft hatches from an insecure location in North Wales. The Environment Agency instigated emergency action under the Radioactive Substances Act 1993 (RSA93), to recover the hatches. Section 30(1) of RSA93 gives the Environment Agency powers to dispose of radioactive waste where it is unlikely the waste will be lawfully disposed of. Funding for this project was provided by the UK Government, within the Surplus Source Disposal Programme. The Environment Agency worked closely with partner regulatory organisations including the Health and Safety Executive (HSE), the Department formore » Transport (DfT) and the Local Authority to ensure the safe packaging, removal and transport of the material to a part-shielded store pending final disposal. The project comprised a number of technical difficulties that needed to be overcome. These included poor existing characterisation of the waste, insecure premises requiring daily lock-down, construction of a temporary containment facility with associated filtered extract and the inclement weather. AMEC NNC's initial risk assessment identified the likelihood of high levels of loose, airborne radiological material. In order to provide adequate protection for personnel, and to prevent the spread of any radioactive contamination, the decision was made to implement radiological containment and to equip contractors with appropriate RPE (Respiratory Protective Equipment). Accurate characterisation of the radiological nature of the material was a crucial objective within the project. This was in order to correctly identify the Proper Shipping Name for consignment for transport, and to ensure that suitable transport containers were used. The packaged wastes were then transported to a secure location for temporary storage prior to final disposal. An innovative route was identified for processing of this material. Beneficial recycling and re-use within the nuclear industry was the outcome. (authors)« less

  20. Effect of recombinant bovine somatotropin (rbST) on cytoplasmic maturation of bovine oocytes and their developmental competence in vitro.

    PubMed

    Kuzmina, Tatjana I; Alm, Hannelore; Denisenko, Vitaly; Tuchscherer, Armin; Kanitz, Wilhelm; Torner, Helmut

    2007-04-01

    The objectives of this study were to evaluate the effects of recombinant bovine somatotropin (rbST) on the nuclear and cytoplasmic maturation of bovine oocytes and their further developmental competence to blastocysts in vitro. We analyzed the mitochondrial activity and concentration of intracellular stored calcium ([Ca(2+)](is)) in matured oocytes and the morphology and chromatin status of produced embryos after in vitro fertilization. Cumulus-oocyte complexes were incubated in TCM 199 containing 10% fetal calf serum (control medium 1: CM 1) or 10% estrus cow serum (control medium 2: CM 2). The culture medium of the treatment groups was modified by supplementation of the control medium with 10 ng/ml rbST (CM 1A and CM 2A), 10(6)/ml granulosa cells (CM 1B and CM 2B), or 10 ng/ml rbST plus 10(6)/ml granulosa cells (CM 1C and CM 2C). No differences were observed in the percentages of oocytes reaching metaphase II between the groups. However, the proportion of blastocysts was highest in treatment groups CM 1C and CM 2C (P<0.05). The type of serum did not alter the positive effect of rbST on the developmental competence of embryos. The fluorescence intensity of metabolically active mitochondria measured by intensity per oocyte (Em 570) after MitoTracker CMTM Ros Orange labeling was significantly increased in oocytes matured in the presence of 10 ng/ml rbST and granulosa cells (309.21 vs. 119.97 microA; P<0.01). In parallel, the concentration of [Ca(2+)](is) in oocytes, determined using fluorophore chlortetracycline, was significantly decreased (0.85 +/- 0.02 vs. 0.97 +/- 0.03 AU; P<0.05). Based on these results, we concluded that rbST, in interaction with granulosa cells stimulates the oxidative activity of ooplasmic mitochondria and decreases the content of [Ca(2+)](is) in oocytes. These facts support the hypothesis that somatotropin influences the developmental competence of bovine oocytes during maturation in vitro, and this effect can be modulated by granulosa cells.

  1. Effects of hand configuration on muscle force coordination, co-contraction and concomitant intermuscular coupling during maximal isometric flexion of the fingers.

    PubMed

    Charissou, Camille; Amarantini, David; Baurès, Robin; Berton, Eric; Vigouroux, Laurent

    2017-11-01

    The mechanisms governing the control of musculoskeletal redundancy remain to be fully understood. The hand is highly redundant, and shows different functional role of extensors according to its configuration for a same functional task of finger flexion. Through intermuscular coherence analysis combined with hand musculoskeletal modelling during maximal isometric hand contractions, our aim was to better understand the neural mechanisms underlying the control of muscle force coordination and agonist-antagonist co-contraction. Thirteen participants performed maximal isometric flexions of the fingers in two configurations: power grip (Power) and finger-pressing on a surface (Press). Hand kinematics and force/moment measurements were used as inputs in a musculoskeletal model of the hand to determine muscular tensions and co-contraction. EMG-EMG coherence analysis was performed between wrist and finger flexors and extensor muscle pairs in alpha, beta and gamma frequency bands. Concomitantly with tailored muscle force coordination and increased co-contraction between Press and Power (mean difference: 48.08%; p < 0.05), our results showed muscle-pair-specific modulation of intermuscular coupling, characterized by pair-specific modulation of EMG-EMG coherence between Power and Press (p < 0.05), and a negative linear association between co-contraction and intermuscular coupling for the ECR/FCR agonist-antagonist muscle pair (r = - 0.65; p < 0.05). This study brings new evidence that pair-specific modulation of EMG-EMG coherence is related to modulation of muscle force coordination during hand contractions. Our results highlight the functional importance of intermuscular coupling as a mechanism contributing to the control of muscle force synergies and agonist-antagonist co-contraction.

  2. A shell-formation related carbonic anhydrase in Crassostrea gigas modulates intracellular calcium against CO2 exposure: Implication for impacts of ocean acidification on mollusk calcification.

    PubMed

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Song, Xiaorui; Wang, Lingling; Song, Linsheng

    2017-08-01

    Ocean acidification (OA) could decrease the shells and skeletons formation of mollusk by reducing the availability of carbonate ions at calcification sites. Carbonic anhydrases (CAs) convert CO 2 to HCO 3 - and play important roles in biomineralization process from invertebrate to vertebrate. In the present study, a CA (designated as CgCA) was identified and characterized in Pacific oyster C. gigas. The cDNA of CgCA was of 927bp encoding a predicted polypeptide of 308 amino acids with a signal peptide and a CA catalytic function domain. The mRNA transcripts of CgCA were constitutively expressed in all tested tissues with the highest levels in mantle and hemocytes. During the early development period, the mRNA transcripts of CgCA could be detected in all the stages with the highest level in D-veliger larvae. Elevated CO 2 increased the mRNA transcripts of CgCA in muscle, mantle, hepatopancreas, gill and hemocytes significantly (p<0.05) and induced the translocation of CgCA in hemocytes and mantle. Moreover, elevated CO 2 also caused the decrease of intracellular Ca 2+ in hemocytes (p<0.05). The inhibition of CA by acetazolamide and suppression of CgCA gene via RNA interference could increase the intracellular Ca 2+ in hemocytes (p<0.05). Besides, the decrease of intracellular Ca 2+ content caused by Ca 2+ reagent ionomycin could affect localization of CgCA in mantle tissue. The results indicated CgCA played essential roles in calcification and elevated CO 2 accelerated the mutual modulation between calcium and CgCA, implying reduced calcification rate and dissolved shells under OA. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 40 CFR 1065.720 - Liquefied petroleum gas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., C3H8 Minimum, 0.85 m3/m3 ASTM D2163-05. Vapor pressure at 38 °C Maximum, 1400 kPa ASTM D1267-02 or 2598-022. Volatility residue (evaporated temperature, 35 °C) Maximum, −38 °C ASTM D1837-02a. Butanes Maximum, 0.05 m3/m3 ASTM D2163-05. Butenes Maximum, 0.02 m3/m3 ASTM D2163-05. Pentenes and heavier Maximum...

  4. The MLH1 c.-27C>A and c.85G>T variants are linked to dominantly inherited MLH1 epimutation and are borne on a European ancestral haplotype.

    PubMed

    Kwok, Chau-To; Vogelaar, Ingrid P; van Zelst-Stams, Wendy A; Mensenkamp, Arjen R; Ligtenberg, Marjolijn J; Rapkins, Robert W; Ward, Robyn L; Chun, Nicolette; Ford, James M; Ladabaum, Uri; McKinnon, Wendy C; Greenblatt, Marc S; Hitchins, Megan P

    2014-05-01

    Germline mutations of the DNA mismatch repair genes MLH1, MSH2, MSH6 or PMS2, and deletions affecting the EPCAM gene adjacent to MSH2, underlie Lynch syndrome by predisposing to early-onset colorectal, endometrial and other cancers. An alternative but rare cause of Lynch syndrome is constitutional epimutation of MLH1, whereby promoter methylation and transcriptional silencing of one allele occurs throughout normal tissues. A dominantly transmitted constitutional MLH1 epimutation has been linked to an MLH1 haplotype bearing two single-nucleotide variants, NM_000249.2: c.-27C>A and c.85G>T, in a Caucasian family with Lynch syndrome from Western Australia. Subsequently, a second seemingly unrelated Caucasian Australian case with the same MLH1 haplotype and concomitant epimutation was reported. We now describe three additional, ostensibly unrelated, cancer-affected families of European heritage with this MLH1 haplotype in association with constitutional epimutation, bringing the number of index cases reported to five. Array-based genotyping in four of these families revealed shared haplotypes between individual families that extended across ≤2.6-≤6.4 megabase regions of chromosome 3p, indicating common ancestry. A minimal ≤2.6 megabase founder haplotype common to all four families was identified, which encompassed MLH1 and additional flanking genes and segregated with the MLH1 epimutation in each family. Our findings indicate that the MLH1 c.-27C>A and c.85G>T variants are borne on a European ancestral haplotype and provide conclusive evidence for its pathogenicity via a mechanism of epigenetic silencing of MLH1 within normal tissues. Additional descendants bearing this founder haplotype may exist who are also at high risk of developing Lynch syndrome-related cancers.

  5. Hippocampal-dependent memory in the plus-maze discriminative avoidance task: The role of spatial cues and CA1 activity.

    PubMed

    Leão, Anderson H F F; Medeiros, André M; Apolinário, Gênedy K S; Cabral, Alícia; Ribeiro, Alessandra M; Barbosa, Flávio F; Silva, Regina H

    2016-05-01

    The plus-maze discriminative avoidance task (PMDAT) has been used to investigate interactions between aversive memory and an anxiety-like response in rodents. Suitable performance in this task depends on the activity of the basolateral amygdala, similar to other aversive-based memory tasks. However, the role of spatial cues and hippocampal-dependent learning in the performance of PMDAT remains unknown. Here, we investigated the role of proximal and distal cues in the retrieval of this task. Animals tested under misplaced proximal cues had diminished performance, and animals tested under both misplaced proximal cues and absent distal cues could not discriminate the aversive arm. We also assessed the role of the dorsal hippocampus (CA1) in this aversive memory task. Temporary bilateral inactivation of dorsal CA1 was conducted with muscimol (0.05 μg, 0.1 μg, and 0.2 μg) prior to the training session. While the acquisition of the task was not altered, muscimol impaired the performance in the test session and reduced the anxiety-like response in the training session. We also performed a spreading analysis of a fluorophore-conjugated muscimol to confirm selective inhibition of CA1. In conclusion, both distal and proximal cues are required to retrieve the task, with the latter being more relevant to spatial orientation. Dorsal CA1 activity is also required for aversive memory formation in this task, and interfered with the anxiety-like response as well. Importantly, both effects were detected by different parameters in the same paradigm, endorsing the previous findings of independent assessment of aversive memory and anxiety-like behavior in the PMDAT. Taken together, these findings suggest that the PMDAT probably requires an integration of multiple systems for memory formation, resembling an episodic-like memory rather than a pure conditioning behavior. Furthermore, the concomitant and independent assessment of emotionality and memory in rodents is relevant to elucidate how these memory systems interact during aversive memory formation. Thus, the PMDAT can be useful for studying hippocampal-dependent memory when it involves emotional content. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Association of cardiac myosin binding protein-C with the ryanodine receptor channel: putative retrograde regulation?

    PubMed

    Stanczyk, Paulina J; Seidel, Monika; White, Judith; Viero, Cedric; George, Christopher H; Zissimopoulos, Spyros; Lai, F Anthony

    2018-06-21

    The cardiac muscle ryanodine receptor-Ca 2+ release channel (RyR2) constitutes the sarcoplasmic reticulum (SR) Ca 2+ efflux mechanism that initiates myocyte contraction, while cardiac myosin binding protein-C (cMyBP-C) mediates regulation of acto-myosin cross-bridge cycling. In this report, we provide the first evidence for the presence of direct interaction between these two proteins, forming a RyR2:cMyBP-C complex. The C-terminus of cMyBP-C binds with the RyR2 N-terminus in mammalian cells and is not mediated by a fibronectin-like domain. Notably, we detected complex formation between both recombinant cMyBP-C and RyR2, as well as with the native proteins in cardiac tissue. Cellular Ca 2+ dynamics in HEK293 cells is altered upon co-expression of cMyBP-C and RyR2, with lowered frequency of RyR2-mediated spontaneous Ca 2+ oscillations, suggesting cMyBP-C exerts a potential inhibitory effect on RyR2-dependent Ca 2+ release. Discovery of a functional RyR2 association with cMyBP-C provides direct evidence for a putative mechanistic link between cytosolic soluble cMyBP-C and SR-mediated Ca 2+ release, via RyR2. Importantly, this interaction may have clinical relevance to the observed cMyBP-C and RyR2 dysfunction in cardiac pathologies, such as hypertrophic cardiomyopathy. © 2018. Published by The Company of Biologists Ltd.

  7. Crystal structure and electrical conductivity of lanthanum-calcium chromites-titanates La 1-xCa xCr 1-yTi yO 3-δ ( x=0-1, y=0-1)

    NASA Astrophysics Data System (ADS)

    Vashook, V.; Vasylechko, L.; Zosel, J.; Gruner, W.; Ullmann, H.; Guth, U.

    2004-10-01

    Five series of perovskite-type compounds in the system La1-xCaxCr1-yTiyO3 with the nominal compositions y = 0 , x = 0 - 0.5 ; y = 0.2 , x = 0.2 - 0.8 ; y = 0.5 , x = 0.5 - 1.0 ; y = 0.8 , x = 0.6 - 1.0 and y = 1 , x = 0.8 - 1 were synthesized by a ceramic technique in air (final heating 1350 °C). On the basis of the X-ray analysis of the samples with (Ca/Ti)⩾1, the phase diagram of the CaTiO3-LaCrIIIO3-CaCrIVO3 quasi-ternary system was constructed. Extended solid solution with a wide homogeneity range is formed in the quasi-ternary system CaCrIVO3-CaTiO3-LaCrIIIO3. The solid solution La(1-x‧-y)Ca(x‧+y)CrIVx‧CrIII(1-x‧-y)TiyO3 exists by up to 0.6-0.7 mol fractions of CaCrIVO3 (x‧ < 0.6 - 0.7) at the experimental conditions. The crystal structure of the compounds is orthorhombic in the space group Pbnm at room temperature. The lattice parameters and the average interatomic distances of the samples within the solid solution ranges decrease uniformly with increasing Ca content. Outside the quasi-ternary system, the nominal compositions La0.1Ca0.9TiO3, La0.2Ca0.8TiO3, La0.4Ca0.6Cr0.2Ti0.8O3 and La0.3Ca0.7Cr0.2Ti0.8O3 in the system La1-xCaxCr1-yTiyO3 were found as single phases with an orthorhombic structure. In the temperature range between 850 and 1000 °C, the synthesized single-phase compositions are stable at pO2=6×10-16-0.21×105 Pa. Oxygen stoichiometry and electrical conductivity of the separate compounds were investigated as functions of temperature and oxygen partial pressure. The chemical stability of these oxides with respect to oxygen release during thermal dissociation decreases with increasing Ca-content. At 900 °C and oxygen partial pressure 1×10-15-0.21×105 Pa, the compounds with x > y (acceptor doped) are p-type semiconductors and those with x < y (donor doped) and x = y are n-type semiconductors. The type and level of electrical conductivity are functions of the concentration ratios of cations occupying the B-sites of the perovskite structures: [Cr3+]/[Cr4+] and [Ti4+]/[Ti3+]. The maximum electrical conductivity at 900 °C and pO2=10-15 Pa was found for the composition La0.1Ca0.9TiO3 (near 50 S/cm) and in air at 900 °C for La0.5Ca0.5CrO3 (close to 100 S/cm).

  8. Superconducting and magnetic properties of Bi 2Sr 2Ca 1- xY xCu 2O y (0≦ x≦1)

    NASA Astrophysics Data System (ADS)

    Yoshizaki, R.; Saito, Y.; Abe, Y.; Ikeda, H.

    1988-07-01

    The effect of substitution of Y atoms for Ca atoms has been studied in the Bi 2Sr 2Ca 1- xY xCu 2O y compound system. For x<0.5, superconductivity is observed and its fractional volume is reduced with increasing x, though the transition temperature of about 85 K is maintained. For x≧0.5 samples, the electrical resistivity behavior can be well described by the three-dimensional variable range hopping conduction, indicating that the system is essentially insulating. In this range of x, magnetic susceptibility shows spin-glass-type cusp at 13 K in the heating process after zero-field cooling and an enhanced cusp at 11 K in the field-cooling process. In the temperature range above about 150 K the Curie-Weiss dependence holds well with a positive paramagnetic Curie temperature, which increases to 40 K with increasing x in the insulating region.

  9. High-speed digital imaging of cytosolic Ca2+ and contraction in single cardiomyocytes.

    PubMed

    O'Rourke, B; Reibel, D K; Thomas, A P

    1990-07-01

    A charge-coupled device (CCD) camera, with the capacity for simultaneous spatially resolved photon counting and rapid frame transfer, was utilized for high-speed digital image collection from an inverted epifluorescence microscope. The unique properties of the CCD detector were applied to an analysis of cell shortening and the Ca2+ transient from fluorescence images of fura-2-loaded [corrected] cardiomyocytes. On electrical stimulation of the cell, a series of sequential subimages was collected and used to create images of Ca2+ within the cell during contraction. The high photosensitivity of the camera, combined with a detector-based frame storage technique, permitted collection of fluorescence images 10 ms apart. This rate of image collection was sufficient to resolve the rapid events of contraction, e.g., the upstroke of the Ca2+ transient (less than 40 ms) and the time to peak shortening (less than 80 ms). The technique was used to examine the effects of beta-adrenoceptor activation, fura-2 load, and stimulus frequency on cytosolic Ca2+ transients and contractions of single cardiomyocytes. beta-Adrenoceptor stimulation resulted in pronounced increases in peak Ca2+, maximal rates of rise and decay of Ca2+, extent of shortening, and maximal velocities of shortening and relaxation. Raising the intracellular load of fura-2 had little effect on the rising phase of Ca2+ or the extent of shortening but extended the duration of the Ca2+ transient and contraction. In related experiments utilizing differential-interference contrast microscopy, the same technique was applied to visualize sarcomere dynamics in contracting cells. This newly developed technique is a versatile tool for analyzing the Ca2+ transient and mechanical events in studies of excitation-contraction coupling in cardiomyocytes.

  10. Spatial nonuniformity of excitation-contraction coupling causes arrhythmogenic Ca2+ waves in rat cardiac muscle.

    PubMed

    Wakayama, Yuji; Miura, Masahito; Stuyvers, Bruno D; Boyden, Penelope A; ter Keurs, Henk E D J

    2005-06-24

    Ca2+ waves underlying triggered propagated contractions (TPCs) are initiated in damaged regions in cardiac muscle and cause arrhythmias. We studied Ca2+ waves underlying TPCs in rat cardiac trabeculae under experimental conditions that simulate the functional nonuniformity caused by local mechanical or ischemic local damage of myocardium. A mechanical discontinuity along the trabeculae was created by exposing the preparation to a small jet of solution with a composition that reduces excitation-contraction coupling (ECC) in myocytes within that segment. The jet solution contained either caffeine (5 mmol/L), 2,3-butanedione monoxime (BDM; 20 mmol/L), or low Ca2+ concentration ([Ca2+]; 0.2 mmol/L). Force was measured with a silicon strain gauge and sarcomere length with laser diffraction techniques in 15 trabeculae. Simultaneously, [Ca2+]i was measured locally using epifluorescence of Fura-2. The jet of solution was applied perpendicularly to a small muscle region (200 to 300 microm) at constant flow. When the jet contained caffeine, BDM, or low [Ca2+], during the stimulated twitch, muscle-twitch force decreased and the sarcomeres in the exposed segment were stretched by shortening normal regions outside the jet. Typical protocols for TPC induction (7.5 s-2.5 Hz stimulus trains at 23 degrees C; [Ca2+]o=2.0 mmol/L) reproducibly generated Ca2+ waves that arose from the border between shortening and stretched regions. Such Ca2+ waves started during force-relaxation of the last stimulated twitch of the train and propagated (0.2 to 2.8 mm/sec) into segments both inside and outside of the jet. Arrhythmias, in the form of nondriven rhythmic activity, were induced when the amplitude of the Ca2+-wave was increased by raising [Ca2+]o. Arrhythmias disappeared rapidly when uniformity of ECC throughout the muscle was restored by turning the jet off. These results show, for the first time, that nonuniform ECC can cause Ca2+ waves underlying TPCs and suggest that Ca2+ dissociated from myofilaments plays an important role in the initiation of Ca2+ waves.

  11. CaFeAl mixed oxide derived heterogeneous catalysts for transesterification of soybean oil to biodiesel.

    PubMed

    Lu, Yongsheng; Zhang, Zaiwu; Xu, Yunfeng; Liu, Qiang; Qian, Guangren

    2015-08-01

    CaAl layered double oxides (LDO) were prepared by co-precipitation and calcined at 750°C, and then applied to biodiesel production by transesterification reaction between methanol and soybean oil. Compared with characteristics of CaFe/LDO and CaAl/LDO, CaFeAl/LDO had the best performance based on prominent catalytic activity and stability, and achieved over 90% biodiesel yield, which stayed stable (over 85%) even after 8 cycles of reaction. The optimal catalytic reaction condition was 12:1M-ratio of methanol/oil, reaction temperatures of 60°C, 270rpm stirring rate, 60min reaction time, and 6% weight-ratio of catalyst/oil. In addition, the CaFeAl/LDO catalyst is insoluble in both methanol and methyl esters and can be easily separated for further reaction, turning it into an excellent alternative for biodiesel synthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Characterization of Zebrafish Cardiac and Slow Skeletal Troponin C Paralogs by MD Simulation and ITC.

    PubMed

    Stevens, Charles M; Rayani, Kaveh; Genge, Christine E; Singh, Gurpreet; Liang, Bo; Roller, Janine M; Li, Cindy; Li, Alison Yueh; Tieleman, D Peter; van Petegem, Filip; Tibbits, Glen F

    2016-07-12

    Zebrafish, as a model for teleost fish, have two paralogous troponin C (TnC) genes that are expressed in the heart differentially in response to temperature acclimation. Upon Ca(2+) binding, TnC changes conformation and exposes a hydrophobic patch that interacts with troponin I and initiates cardiac muscle contraction. Teleost-specific TnC paralogs have not yet been functionally characterized. In this study we have modeled the structures of the paralogs using molecular dynamics simulations at 18°C and 28°C and calculated the different Ca(2+)-binding properties between the teleost cardiac (cTnC or TnC1a) and slow-skeletal (ssTnC or TnC1b) paralogs through potential-of-mean-force calculations. These values are compared with thermodynamic binding properties obtained through isothermal titration calorimetry (ITC). The modeled structures of each of the paralogs are similar at each temperature, with the exception of helix C, which flanks the Ca(2+) binding site; this region is also home to paralog-specific sequence substitutions that we predict have an influence on protein function. The short timescale of the potential-of-mean-force calculation precludes the inclusion of the conformational change on the ΔG of Ca(2+) interaction, whereas the ITC analysis includes the Ca(2+) binding and conformational change of the TnC molecule. ITC analysis has revealed that ssTnC has higher Ca(2+) affinity than cTnC for Ca(2+) overall, whereas each of the paralogs has increased affinity at 28°C compared to 18°C. Microsecond-timescale simulations have calculated that the cTnC paralog transitions from the closed to the open state more readily than the ssTnC paralog, an unfavorable transition that would decrease the ITC-derived Ca(2+) affinity while simultaneously increasing the Ca(2+) sensitivity of the myofilament. We propose that the preferential expression of cTnC at lower temperatures increases myofilament Ca(2+) sensitivity by this mechanism, despite the lower Ca(2+) affinity that we have measured by ITC. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  13. The influence of muscle length on the fatigue-related reduction in joint range of motion of the human dorsiflexors.

    PubMed

    Cheng, Arthur J; Davidson, Andrew W; Rice, Charles L

    2010-06-01

    The fatigue-related reduction in joint range of motion (ROM) during dynamic contraction tasks may be related to muscle length-dependent alterations in torque and contractile kinetics, but this has not been systematically explored previously. Twelve young men performed a repetitive voluntary muscle shortening contraction task of the dorsiflexors at a contraction load of 30% of maximum voluntary isometric contraction (MVC) torque, until total 40 degrees ROM had decreased by 50% at task failure (POST) to 20 degrees ROM. At both a short (5 degrees dorsiflexion) and long muscle length (35 degrees plantar flexion joint angle relative to a 0 degrees neutral ankle joint position), voluntary activation, MVC torque, and evoked tibialis anterior contractile properties of a 52.8 Hz high-frequency isometric tetanus [peak evoked torque, maximum rate of torque development (MRTD), maximum rate of relaxation (MRR)] were evaluated at baseline (PRE), at POST, and up to 10 min of recovery. At POST, we measured similar fatigue-related reductions in torque (voluntary and evoked) and slowing of contractile kinetics (MRTD and MRR) at both the short and long muscle lengths. Thus, the fatigue-related reduction in ROM could not be explained by length-dependent fatigue. Although torque (voluntary and evoked) at both muscle lengths was depressed and remained blunted throughout the recovery period, this was not related to the rapid recovery of ROM at 0.5 min after task failure. The reduction in ROM, however, was strongly related to the reduction in joint angular velocity (R(2) = 0.80) during the fatiguing task, although additional factors cannot yet be overlooked.

  14. Development of Laser-Mediated Nanodroplet Real-Time PCR on Circulating Tumor Cells (CTC) by Microfilter Platform

    DTIC Science & Technology

    2015-06-01

    DNA hybridization using fluorescence,”   Biopolymers 95(7), 472–486 (2011). 26. J.-L. Mergny and L. Lacroix,  “Analysis of thermal melting curves...Microfilter Platform PRINCIPAL INVESTIGATOR: Gregory W. Faris, Ph.D. CONTRACTING ORGANIZATION : SRI International Menlo Park, CA 94025 REPORT DATE...Ph.D. 5e. TASK NUMBER E-Mail: ! ! 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SRI International AND ADDRESS(ES) 8

  15. Targeted GLUT-4 deficiency in the heart induces cardiomyocyte hypertrophy and impaired contractility linked with Ca(2+) and proton flux dysregulation.

    PubMed

    Domenighetti, Andrea A; Danes, Vennetia R; Curl, Claire L; Favaloro, Jennifer M; Proietto, Joseph; Delbridge, Lea M D

    2010-04-01

    There is clinical evidence to suggest that impaired myocardial glucose uptake contributes to the pathogenesis of hypertrophic, insulin-resistant cardiomyopathy. The goal of this study was to determine whether cardiac deficiency of the insulin-sensitive glucose transporter, GLUT4, has deleterious effect on cardiomyocyte excitation-contraction coupling. Cre-Lox mouse models of cardiac GLUT4 knockdown (KD, 85% reduction) and knockout (KO, >95% reduction), which exhibit similar systemic hyperinsulinemic and hyperglycemic states, were investigated. The Ca(2+) current (I(Ca)) and Na(+)-Ca(2+) exchanger (NCX) fluxes, Na(+)-H(+) exchanger (NHE) activity, and contractile performance of GLUT4-deficient myocytes was examined using whole-cell patch-clamp, epifluorescence, and imaging techniques. GLUT4-KO exhibited significant cardiac enlargement characterized by cardiomyocyte hypertrophy (40% increase in cell area) and fibrosis. GLUT4-KO myocyte contractility was significantly diminished, with reduced mean maximum shortening (5.0+/-0.4% vs. 6.2+/-0.6%, 5 Hz). Maximal rates of shortening and relaxation were also reduced (20-25%), and latency was delayed. In GLUT4-KO myocytes, the I(Ca) density was decreased (-2.80+/-0.29 vs. -5.30+/-0.70 pA/pF), and mean I(NCX) was significantly increased in both outward (by 60%) and inward (by 100%) directions. GLUT4-KO expression levels of SERCA2 and RyR2 were reduced by approximately 50%. NHE-mediated H(+) flux in response to NH(4)Cl acid loading was markedly elevated GLUT4-KO myocytes, associated with doubled expression of NHE1. These findings demonstrate that, independent of systemic endocrinological disturbance, cardiac GLUT4 deficiency per se provides a lesion sufficient to induce profound alterations in cardiomyocyte Ca(2+) and pH homeostasis. Our investigation identifies the cardiac GLUT4 as a potential primary molecular therapeutic target in ameliorating the functional deficits associated with insulin-resistant cardiomyopathy. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  16. Study and Evaluation of Current and Future Aircraft Loaders

    DTIC Science & Technology

    1986-08-01

    Tigers Airlines JFK Airport , NY 10 Feb 86 Boeing Military Airplane Co. Boeing Commercial Airplane Co. Seattle, WA 11 Feb 86 Korean Airlines LAX, CA 12...Nash Boeing Aircraft Co., Seattle, WA Mr. J. Nelson JFK Airport , NY Mr. P. O’Brien ASD/ENCA Wright-Patterson AFB, OH Mr. C. Outran HQ AFLC/DSTMA...Locations 15 Oct 85 TWA Freight Terminal Laimbert Int’l Airport , St. Louis, mO 22 Nov 85 Lockheed - Georgia Aircraft Co. Marietta, GA 13 Dec 85 Flying

  17. Structure and electrical properties of <001> textured (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Ye, S. K.; Fuh, J. Y. H.; Lu, L.

    2012-06-01

    <001> textured (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) lead-free piezoelectric ceramics were prepared by templated-grain growth method using BaTiO3 as template. The degree of orientation and the microstructure of the ceramics with different amount of template were investigated. The electrical properties of the textured-ceramics in the optimized condition were dramatically enhanced compared with randomly-oriented BCTZ ceramics. The textured BCTZ ceramics showed high piezoelectric constants d33 = 470 pC/N and d31 = -170 pC/N, and high electromechanical coupling factors kp = 44% and k31 = 22%. In addition, the Curie point of the textured ceramics revealed an increase with the template content.

  18. Beverly Hayes | Frederick National Laboratory for Cancer Research

    Cancer.gov

    Employee name: Bev Hayes Directorate: Management Operations Department or lab: Contracts and Acquisitions How many years have you worked at the Frederick National Laboratory? Four months going on one year! Job responsibilities: With the C&A manageme

  19. Modulation of contraction by intracellular Na+ via Na(+)-Ca2+ exchange in single shark (Squalus acanthias) ventricular myocytes.

    PubMed Central

    Näbauer, M; Morad, M

    1992-01-01

    1. The effect of direct alteration of intracellular Na+ concentration on contractile properties of whole-cell clamped shark ventricular myocytes was studied using an array of 256 photodiodes to monitor the length of the isolated myocytes. 2. In myocytes dialysed with Na(+)-free solution, the voltage dependence of Ca2+ current (ICa) and contraction were similar and bell shaped. Contractions activated at all voltages were completely suppressed by nifedipine (5 microM), and failed to show significant tonic components, suggesting dependence of the contraction on Ca2+ influx through the L-type Ca2+ channel. 3. In myocytes dialysed with 60 mM Na+, a ICa-dependent and a ICa-independent component of contraction could be identified. The Ca2+ current-dependent component was prominent in voltages between -30 to +10 mV. The ICa-independent contractions were maintained for the duration of depolarization, increased with increasing depolarization between +10 to +100 mV, and were insensitive to nifedipine. 4. In such myocytes, repolarization produced slowly decaying inward tail currents closely related to the time course of relaxation and the degree of shortening prior to repolarization. 5. With 60 mM Na+ in the pipette solution, positive clamp potentials activated decaying outward currents which correlated to the size of contraction. These outward currents appeared to be generated by the Na(+)-Ca(2+)-exchanger since they depended on the presence of intracellular Na+, and were neither suppressed by nifedipine nor by K+ channel blockers. 6. The results suggest that in shark (Squalus acanthias) ventricular myocytes, which lack functionally relevant Ca2+ release pools, both Ca2+ channel and the Na(+)-Ca2+ exchanger deliver sufficient Ca2+ to activate contraction, though the effectiveness of the latter mechanism was highly dependent on the [Na+]i. PMID:1338467

  20. NAVSUP Global Logistics Support

    DTIC Science & Technology

    2012-08-01

    Support $3.5 M Ill SB Contracting Actions Ill SB Value 35% of total spend to Small Business ! NAVAL SUPPLY SYSTEMS COMMAND • Procurement • Barge...Other services now using as well • Awarded Aug 2011, Features: • 100% Sma II Business Set Aside ! • 25 multiple award task order contracts to 8...UP- GLOBAL LOGISTICS I · -~ --; •• ~.c. SUPPORT ,.. NAVAL SUPPLY SYSTEMS COMMAND Fiscal Year 2011 Small Business Contracting Spend: 28,000 actions

  1. The polymorphism -863C/A in tumour necrosis factor-alpha gene contributes an independent association to gout.

    PubMed

    Chang, S-J; Tsai, P-C; Chen, C-J; Lai, H-M; Ko, Y-C

    2007-11-01

    To investigate the associations between polymorphisms in the promoter of the tumour necrosis factor-alpha (TNF-alpha) gene and gout. The polymorphisms -308G/A and -863C/A in the TNF-alpha gene were determined in 106 gout patients and 159 healthy controls among male Taiwanese using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. The biochemical markers, including Glutamic-oxaloacetic transaminase (GOT), Glutamic-pyruvic transaminase (GPT), uric acid, creatinine, total cholesterol (TC), triglycerides (TG), body mass index (BMI) and hypertension, as well as alcohol consumption were measured. The gout patients had 9.43% (10/106) with genotype AA at polymorphism -863C/A showing a significantly higher fraction than controls (0.63%; 1/159, P < 0.001). The crude results also showed that the gout patients had significantly higher portions of abnormal GOT, GPT, creatinine, TC, TG, alcohol consumption, hypertension and hyperuricaemia than controls (P < 0.05), but the -308G/A, BMI and genotype CA at -863C/A did not show the same significant difference (P > 0.05). After adjustment by a stepwise logistic regression method, the hyperuricaemia, creatinine, GPT, TG and alcohol consumption as well as genotype AA at polymorphism -863C/A were found to be significantly associated with gout. The genotype AA at polymorphism -863C/A in a recessive model showed a significant association with developing gout independent of hyperuricaemia, abnormal creatinine, higher TG, GPT and alcohol consumption.

  2. Application of Cognitive Task Analysis in User Requirements and Prototype Design Presentation/Briefing

    DTIC Science & Technology

    2005-10-01

    AFRL-HE-WP-TP-2005-0030 AIR FORCE RESEARCH LABORATORY Application of Cognitive Task Analysis in User Requirements and Prototype Design Presentation...TITLE AND SUBTITLE 5a. CONTRACT NUMBER FA8650-04-C-6406 Application of Cognitive Task Analysis in User Requirements 5b.GRANTNUMBER and Prototype...maintainer experience 21 21 Questions & Answers Application of Cognitive Task Analysis in User Requirements Definition and Prototype Design Christopher Curtis

  3. Effect of micromolar Ca2+ on NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex and possible role of Ca2+ in signal amplification.

    PubMed

    Lawlis, V B; Roche, T E

    1980-11-20

    NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex was compared at 10 microM free Ca2+ or in the absence of Ca2+ (i.e., less than 1.0 nM free Ca2+). In the presence of Ca2+, NADH inhibition was appreciably decreased for a wide range of NADH:NAD+ ratios. A half-maximal decrease in NADH inhibition occurred at slightly less than 1 microM free Ca/+ (as determined with EGTA-Ca buffers). Of necessity this was observed on top of an effect of Ca2+ on the S0.5 for alpha-ketoglutarate which was decreased by Ca2+ with a half-maximal effect at a similar concentration. The effect of Ca2+ on NADH inhibition was not observed in assays of the dihydrolipoyl dehydrogenase component (using dihydrolipoamide as a substrate) or in assays of bovine kidney pyruvate dehydrogenase complex. This indicates that the overall reaction catalyzed by the alpha-ketoglutarate dehydrogenase complex is required to elicit the effect of Ca2+ on NADH inhibition. At a fixed alpha-ketoglutarate concentration (50 microM), removal of Ca2+ reduced the activity of the alpha-ketoglutarate dehydrogenase complex by 8.5-fold (due to an increase in S0.5 for alpha-ketoglutarate) and, in the presence of different NADH:NAD+ ratios, decreased the activity of the complex by 50 to 100-fold. Effects of the phosphate potential (ATP/ADPxPi) or a combination of the phosphate potential and NADH:NAD+ ratio are also described. The possibility that the level of intramitochondrial free Ca/+ serves as a signal amplifier normally coupled to the energy state of mitochondria is discussed.

  4. Micro-Electromechanical Instrument and Systems Development at the Charles Stark Draper Laboratory

    NASA Technical Reports Server (NTRS)

    Connelly, J. H.; Gilmore, J. P.; Weinberg, M. S.

    1995-01-01

    Several generations of micromechanical gyros and accelerometers have been developed at Draper. Current design effort centers on tuning-fork gyro design and pendulous accelerometer configurations. Over 200 gyros of different generations have been packaged and tested. These units have successfully performed across a temperature range of -40 to 85 degrees C, and have survived 30,000-g shock tests along all axes. Draper is currently under contract to develop an integrated micro-mechanical inertial sensor assembly (MMISA) and global positioning system (GPS) receiver configuration. The ultimate projections for size, weight, and power for an MMISA, after electronic design of the application specific integrated circuit (ASIC ) is completed, are 2 x 2 x 0.5 cm, 5 gm, and less than 1 W, respectively. This paper describes the fabrication process, the current gyro and accelerometer designs, and system configurations.

  5. Mechanisms mediating substance P-induced contraction in the rat iris in vitro.

    PubMed

    Grumann-Júnior, A; Dias, M A; Alves, R V; Boteon, J E; Calixto, J B

    2000-06-01

    To determine some of the mechanisms by which substance P (SP) induces contraction in the isolated rat iris. Rings of rat iris were mounted in a 5-ml organ chamber containing Krebs solution at 37 degrees C under basal tension of 75 mg, and isometric tension was recorded. Substance P produced graded contraction in the rat iris, being approximately 40-fold more potent than carbachol. Peptidase inhibitors (captopril, phosphoramidon, thiorphan) did not affect the SP response. The SP contraction was dependent on external Ca2+ by a mechanism resistant to both nifedipine and omega-conotoxin GVIA. Atropine and tetrodotoxin significantly shifted the SP response to the right (three- and fivefold, respectively). Neither phorbol nor genistein altered the SP-induced contraction, whereas staurosporine caused a weak inhibition. Indomethacin, pyrilamine, guanethidine, 8-37 calcitonin gene-related peptide (CGRP) fragment, and NG-nitro-L-arginine methyl ester had no effect on SP response. All the natural tachykinin agonists caused concentration-dependent contraction in rat iris with similar maximal responses. The NK3 selective agonist senktide caused graded contraction, being approximately 150-fold more active than the NK2 selective agonist [beta-ala] NKA. The NK1 selective agonist SP methyl ester induced a small contraction. The NK3 and NK2 antagonists SR 142801 and SR 48968 shifted the SP response to the right. Schilds plots gave pA2 (negative logarithm of the molar concentration of antagonist causing a twofold rightward displacement of the concentration response curves) values of 9.37 and 7.97 and slopes of 0.70 and 1.02, respectively. Substance P produces a potent contraction in the isolated rat iris that seems to depend on the neural release of acetylcholine by tetrodotoxin-sensitive mechanisms. Its response relies largely on external Ca2+, through mechanisms independent of activation of L- or N-type Ca2+ channels, and is probably mediated via activation of NK3 and NK2 receptors.

  6. Technology Insertion-Engineering Services Process Characterization. Task Order No. 1. Book 2 of 5. Database Documentation Book. OO-ALC MANPRA (C5 Main Landing Gear - WCD’S)

    DTIC Science & Technology

    1989-12-15

    ORDER NO. 1 BOOK 2 OF 5 DATABASE DOCUMENTATION BOOK 00-ALC MANPRA *(C5 MAIN LANDING GEAR- WCD’S) CONTRACT SUMMARY REPORT , 15 DECEMBER 1989 ’.1 - CONTRACT...ORIQ 1 . T A 1~4 M E* X C I" El 1 -:11 E:XCE:EI:IIE:U RE:CORI’ RFiS CvAUiS FOREXE IN REWORK LI[MITS Ill FINAL DESTINATION 22. COOROINATION/INITIATING MCC

  7. Vasodilator activity of the essential oil from aerial parts of Pectis brevipedunculata and its main constituent citral in rat aorta.

    PubMed

    Pereira, Sharlene Lopes; Marques, André Mesquita; Sudo, Roberto Takashi; Kaplan, Maria Auxiliadora Coelho; Zapata-Sudo, Gisele

    2013-03-07

    The essential oil of Pectis brevipedunculata (EOPB), a Brazilian ornamental aromatic grass, is characterized by its high content of citral (81.9%: neral 32.7% and geranial 49.2%), limonene (4.7%) and α-pinene (3.4%). Vasodilation induced by EOPB and isolated citral was investigated in pre-contracted vascular smooth muscle, using thoracic aorta from Wistar Kyoto (WKY) rats which was prepared for isometric tension recording. EOPB promoted intense relaxation of endothelium-intact and denuded aortic rings with the concentration to induce 50% of the maximal relaxation (IC50) of 0.044% ± 0.006% and 0.093% ± 0.015% (p < 0.05), respectively. The IC50 values for citral in endothelium-intact and denuded rings were 0.024% ± 0.004% and 0.021% ± 0.004%, respectively (p > 0.05). In endothelium-intact aorta, EOPB-induced vasorelaxation was significantly reduced by L-NAME, a nitric oxide synthase inhibitor. The vasodilator activity of citral was increased in the KCl-contracted aorta and citral attenuated the contracture elicited by Ca2+ in depolarized aorta. EOPB and citral elicited vasorelaxation on thoracic aorta by affecting the NO/cyclic GMP pathway and the calcium influx through voltage-dependent L-type Ca2+ channels, respectively.

  8. Alpha List of Prime Contract Awards. Oct 92-Sep 93. FY93. (Nihon Elevator Institution Co. - Pevar Company The). Part 14

    DTIC Science & Technology

    1994-03-01

    H.CO0)00)N.- 00 0000)U)N10 61010 əU 1-0 SN 0)00 40)00 -4 j 10 -H wow’ HN.400000 00.4000000 0 - 1-0 LI0 .4 0 000000000 w H I00)ON 110 z KL U )L H 0o...N 3 OI~eni M0 0. -4 44JID (fl.40iDLON 0 ID KO10000 wL N a0Ig 00 - U 41N N 01(V W1V 05.- IM IeC ,4 CF) CVi.-4 L. 9 0 .’is)N(i(iVi Dn 004 3000 CN EN W L...1-01 00 u i p 1)0 n1c0ca1)101101010coca10101101coca 0101010110101010cow010110ow 10mm 1010101 II 0 Om 40cr 1 e Iec 1 ew o 110u14 ON 01.01 i v)0 0r OP

  9. Mechanism of auxiliary β-subunit-mediated membrane targeting of L-type (CaV1.2) channels

    PubMed Central

    Fang, Kun; Colecraft, Henry M

    2011-01-01

    Abstract Ca2+ influx via CaV1/CaV2 channels drives processes ranging from neurotransmission to muscle contraction. Association of a pore-forming α1 and cytosolic β is necessary for trafficking CaV1/CaV2 channels to the cell surface through poorly understood mechanisms. A prevalent idea suggests β binds the α1 intracellular I–II loop, masking an endoplasmic reticulum (ER) retention signal as the dominant mechanism for CaV1/CaV2 channel membrane trafficking. There are hints that other α1 subunit cytoplasmic domains may play a significant role, but the nature of their potential contribution is unclear. We assessed the roles of all intracellular domains of CaV1.2-α1C by generating chimeras featuring substitutions of all possible permutations of intracellular loops/termini of α1C into the β-independent CaV3.1-α1G channel. Surprisingly, functional analyses demonstrated α1C I–II loop strongly increases channel surface density while other cytoplasmic domains had a competing opposing effect. Alanine-scanning mutagenesis identified an acidic-residue putative ER export motif responsible for the I–II loop-mediated increase in channel surface density. β-dependent increase in current arose as an emergent property requiring four α1C intracellular domains, with the I–II loop and C-terminus being essential. The results suggest β binding to the α1C I–II loop causes a C-terminus-dependent rearrangement of intracellular domains, shifting a balance of power between export signals on the I–II loop and retention signals elsewhere. PMID:21746784

  10. Isolated effects of peripheral arm and central body cooling on arm performance.

    PubMed

    Giesbrecht, G G; Wu, M P; White, M D; Johnston, C E; Bristow, G K

    1995-10-01

    Whole body cooling impairs manual arm performance. The independent contributions of local (peripheral) and/or whole body (central) cooling are not known. Therefore, a protocol was developed in which the arm and the rest of the body could be independently cooled. Biceps temperature (Tmus), at a depth of 20 mm, and esophageal temperature (Tes) were measured. Six subjects were immersed to the clavicles in a tank (body tank) of water under 3 conditions: 1) cold body-cold arm (CB-CA); 2) warm body-cold arm (WB-CA); and 3) cold body-warm arm (CB-WA). In the latter two conditions, subjects placed their dominant arm in a separate (arm) tank. Water temperature (Tw) in each tank was independently controlled. In conditions requiring cold body and/or cold arm, Tw in the appropriate tanks was 8 degrees C. In conditions requiring warm body and/or warm arm, Tw in the appropriate tanks was adjusted between 29 and 38 degrees C to maintain body/arm temperature at baseline values. A battery of 6 tests, requiring fine or gross motor movements, were performed immediately before immersion and after 15, 45, and 70 minutes of immersion. In CB-CA, Tes decreased from an average of 37.2 to 35.6 degrees C and Tmus decreased from 34.6 to 22.0 degrees C. In WB-CA, Tmus decreased to 18.1 degrees C (Tes = 37.1 degrees C), and in CB-WA, Tes decreased to 35.8 degrees C (Tmus = 34.5 degrees C). By the end of immersion, there were significant decrements (43-85%) in the performance of all tests in CB-CA and WB-CA (p < 0.0002); scores for each test were similar in these two conditions. There was no significant change in scores throughout the CB-WA condition. In both conditions with arm cooling (i.e., WB-CA and CB-CA), Tmus accounted for 85-98% of the variance in all tests. When the core was cooled in the CB-WA condition, Tes was significantly correlated to scores in only two tests (accounted for 90 and 93% of the variance) although the actual effect was small. In the CB-CA condition, partial correlations indicated that Tes accounted for 4-10% of the variance in scores of 4 tests. We conclude that cooling of the body and/or the arm elicits large decrements in finger, hand and arm performance. The decrements are due almost entirely to the local effects of arm tissue cooling.

  11. Technical Reports Prepared Under Contract N00014-76-C-0475.

    DTIC Science & Technology

    1987-05-29

    264 Approximations to Densities in Geometric H. Solomon 10/27/78 Probability M.A. Stephens 3. Technical Relort No. Title Author Date 265 Sequential ...Certain Multivariate S. Iyengar 8/12/82 Normal Probabilities 323 EDF Statistics for Testing for the Gamma M.A. Stephens 8/13/82 Distribution with...20-85 Nets 360 Random Sequential Coding By Hamming Distance Yoshiaki Itoh 07-11-85 Herbert Solomon 361 Transforming Censored Samples And Testing Fit

  12. Evaluation of Catalyst Activity - Detoxification of Chemical Warfare Agents Under Oxidation and Hydrolysis Conditions

    DTIC Science & Technology

    2006-08-15

    Report August 15, 2006 CUBRC Contract No.: 6774 Prime Contract No.: W911-NF-05-C-0041 Subcontract No.:CBR05.1 Submitted to: TDA... CUBRC Approval: 8/15/06 David J. Mangino – Director, Life Sciences Date CUBRC 2 of 40 Contents 1. SUMMARY...POSSIBLE HYDROLYSIS DEGRADATION PRODUCTS – MASS SPECTRA ............36 CUBRC 3 of 40 1. SUMMARY Potential catalysts for the

  13. A Measure of Search Efficiency in a Real World Search Task (PREPRINT)

    DTIC Science & Technology

    2009-02-16

    Search Task 5a. CONTRACT NUMBER N00173-08-1-G030 5b. GRANT NUMBER NRL BAA 08-09, 55-07-01 5c. PROGRAM ELEMENT NUMBER 0602782N 6. AUTHOR(S... Beck , Melissa R. Ph.D (LSU) Maura C. Lohrenz (NRL Code 7440.1) J. Gregory Trafton (NRL Code 5515) 5d. PROJECT NUMBER 08294 5e. TASK NUMBER... Beck 19b. TELEPHONE NUMBER (Include area code) (225)578-7214 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 A measure of search

  14. 43. VIEW OF NORTHWEST CORNER OF STATION 111 WEST ANTEROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. VIEW OF NORTHWEST CORNER OF STATION 111 WEST ANTEROOM SHOWING HYDRAULIC ACTUATOR ARM (LEFT) AND PUMP (RIGHT) FOR WEST ENVIRONMENTAL DOOR ON NORTH FACE OF MST. NOTE LOCATION NEAR FLOOR RATHER THAN NEAR CEILING AS ON STATION 85.5 (CA-133-1-C-38). - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. Nitric oxide in the dorsal hippocampal area is involved on muscimol state-dependent memory in the step-down passive avoidance test.

    PubMed

    Jafari-Sabet, Majid; Khodadadnejad, Mohammad-Amin; Ghoraba, Saeed; Ataee, Ramin

    2014-02-01

    In the present study, the effects of intra-dorsal hippocampal (intra-CA1) injections of nitric oxide (NO) agents on muscimol state-dependent memory were examined in mice. A single-trial step-down passive avoidance task was used for the assessment of memory retrieval in adult male NMRI mice. Post-training intra-CA1 administration of a GABAA receptor agonist, muscimol (0.05 and 0.1 μg/mouse) dose dependently induced impairment of memory retention. Pre-test injection of muscimol (0.05 and 0.1 μg/mouse) induced state-dependent retrieval of the memory acquired under post-training muscimol (0.1 μg/mouse, intra-CA1) influence. Pre-test injection of a NO precursor, L-arginine (1 and 2 μg/mouse, intra-CA1) improved memory retention, although the low dose of the drug (0.5 μg/mouse) did not affect memory retention. Pre-test injection of an inhibitor of NO-synthase, L-NAME (0.5 and 1 μg/mouse, intra-CA1) impaired memory retention, although the low dose of the drug (0.25 μg/mouse) did not affect memory retention. In other series of experiments, pre-test intra-CA1 injection of L-arginine (0.25 and 0.5 μg/mouse) 5 min before the administration of muscimol (0.1 μg/mouse, intra-CA1) dose dependently inhibited muscimol state-dependent memory. Pre-test intra-CA1 administration of L-arginine (0.125, 0.25 and 0.5 μg/mouse) by itself cannot affect memory retention. Pre-test intra-CA1 injection of L-NAME (0.25 μg/mouse, intra-CA1) reversed the memory impairment induced by post-training administration of muscimol (0.1 μg/mouse, intra-CA1). Moreover, pre-test administration of L-NAME (0.125 and 0.25 μg/mouse, intra-CA1) with an ineffective dose of muscimol (0.025 μg/mouse, intra-CA1) significantly restored the retrieval and induced muscimol state-dependent memory. Pre-test intra-CA1 administration of L-NAME (0.0625, 0.125 and 0.25 μg/mouse) by itself cannot affect memory retention. It may be suggested that the nitric oxide in the dorsal hippocampal area play an important role in muscimol state-dependent memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Prime Contractors with Awards Over $25,000 by Name, Location, and Contract Number, Fiscal Year 1988. Part 6. (Knowledge Systems Corporation-Mitchell Construction Company).

    DTIC Science & Technology

    1988-01-01

    aIZ I < u .I U :3 0 C) L 40..C Iz CA cc I ) 000 Ior 000 L’I U 000 *) ca L) I ) c UU <H i U 0 0 o 0~~~ NZ I Z M czt I) ZZ z 04 I I 0 0 0r 0. u CZ 0 0 I...a -4 - 0 c0 a 0 a.l En a.co( az ta- ra 0 L) mIf~( -. - - cZ U-C)-X a 0 - - 4 -. 0a a - 1a.34 a ~ 7 af -. a C a Ha Oa a 0 a ZE o.aa cc a aa Lu a

  17. 41 CFR 102-85.30 - Are there special rules for certain Federal customers?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Are there special rules for certain Federal customers? 102-85.30 Section 102-85.30 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85...

  18. 41 CFR 102-85.110 - Can the allowance amount be changed?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Can the allowance amount be changed? 102-85.110 Section 102-85.110 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  19. 41 CFR 102-85.165 - What are standard levels of service?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What are standard levels of service? 102-85.165 Section 102-85.165 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  20. 41 CFR 102-85.130 - How are exemptions from Rent granted?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false How are exemptions from Rent granted? 102-85.130 Section 102-85.130 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  1. 41 CFR 102-85.90 - What is a tenant improvement allowance?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is a tenant improvement allowance? 102-85.90 Section 102-85.90 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  2. 41 CFR 102-85.45 - When is an Occupancy Agreement required?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false When is an Occupancy Agreement required? 102-85.45 Section 102-85.45 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  3. 41 CFR 102-85.195 - Does GSA provide special services?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Does GSA provide special services? 102-85.195 Section 102-85.195 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  4. 41 CFR 102-85.30 - Are there special rules for certain Federal customers?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are there special rules for certain Federal customers? 102-85.30 Section 102-85.30 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85...

  5. Functional coupling of TRPV4 channels and BK channels in regulating spontaneous contractions of the guinea pig urinary bladder.

    PubMed

    Isogai, Ayu; Lee, Ken; Mitsui, Retsu; Hashitani, Hikaru

    2016-09-01

    We investigated the role of TRPV4 channels (TRPV4) in regulating the contractility of detrusor smooth muscle (DSM) and muscularis mucosae (MM) of the urinary bladder. Distribution of TRPV4 in DSM and MM of guinea-pig bladders was examined by fluorescence immunohistochemistry. Changes in the contractility of DSM and MM bundles were measured using isometric tension recording. Intracellular Ca(2+) dynamics were visualized by Cal-520 fluorescent Ca(2+) imaging, while membrane potential changes were recorded using intracellular microelectrode technique. DSM and MM expressed TRPV4 immunoreactivity. GSK1016790A (GSK, 1 nM), a TRPV4 agonist, evoked a sustained contraction in both DSM and MM associated with a cessation of spontaneous phasic contractions in a manner sensitive to HC-067047 (10 μM), a TRPV4 antagonist. Iberiotoxin (100 nM) and paxilline (1 μM), large conductance Ca(2+)-activated K(+) (BK) channel blockers restored the spontaneous contractions in GSK. The sustained contractions in DSM and MM were reduced by nifedipine (10 μM), a blocker of L-type voltage-dependent Ca(2+) channels (LVDCCs) by about 40 % and by nominally Ca(2+)-free solution by some 90 %. GSK (1 nM) abolished spontaneous Ca(2+) transients, increased basal Ca(2+) levels and also prevented spontaneous action potential discharge associated with DSM membrane hyperpolarization. In conclusion, Ca(2+) influx through TRPV4 appears to activate BK channels to suppress spontaneous contractions and thus a functional coupling of TRPV4 with BK channels may act as a self-limiting mechanism for bladder contractility during its storage phase. Despite the membrane hyperpolarization in GSK, Ca(2+) entry mainly through TRPV4 develops the tonic contraction.

  6. Carbachol induces Ca(2+)-dependent contraction via muscarinic M2 and M3 receptors in rat intestinal subepithelial myofibroblasts.

    PubMed

    Iwanaga, Koichi; Murata, Takahisa; Okada, Muneyoshi; Hori, Masatoshi; Ozaki, Hiroshi

    2009-07-01

    Intestinal myofibroblasts (IMFs) that exist adjacent to the basement membrane of intestines have contractility and contribute to physical barriers of the intestine. Nerve endings distribute adjacent to IMFs, suggesting neurotransmitters may influence IMFs motility; however, there is no direct evidence showing the interaction. Here, we isolated IMFs from rat colon and investigated the effect of acetylcholine on IMFs contractility. In the collagen gel contraction assay, carbachol (1 - 10 microM) and the muscarinic receptor agonist bethanechol (30 - 300 microM) dose-dependently induced IMFs contraction. Pretreatment with the muscarinic receptor antagonist atropine (1 - 10 nM) inhibited carbachol-induced contraction. In RT-PCR, mRNA expression of all muscarinic receptor subtypes (M(1) - M(5)) was detected in IMFs. Subsequently we found pretreatment with the muscarinic M(2) receptor antagonist 11-([2-[(diethylamino)methyl]-1-piperdinyl]acetyl)-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepine-6-one (AF-DX116) (10 and 30 nM) or the muscarinic M(3) receptor antagonist 4-diphenylacetoxy-N-methyl-piperidine (4-DAMP) (3 and 10 nM) dose-dependently inhibited carbachol-induced contraction. In Ca(2+) measurement, 1 - 10 microM carbachol and 30 - 300 microM bethanechol elevated the intracellular Ca(2+) concentration ([Ca(2+)](i)) in IMFs. Atropine (10 nM) eliminated carbachol-induced [Ca(2+)](i) elevation. The Ca(2+)-channel blocker LaCl(3) (3 microM) abolished carbachol-induced [Ca(2+)](i) elevation and contraction. Furthermore, AF-DX116 and 4-DAMP dose-dependently inhibited the carbachol-induced [Ca(2+)](i) elevation. These observations suggest that acetylcholine elicits Ca(2+)-dependent IMF contraction through muscarinic M(2) and M(3) receptors.

  7. Crystal Structure, Piezoelectric and Dielectric Properties of (Li, Ce)4+, Nb5+ and Mn2+ Co-doped CaBi4Ti4O15 High-Temperature Ceramics

    NASA Astrophysics Data System (ADS)

    Xin, Deqiong; Chen, Qiang; Wu, Jiagang; Bao, Shaoming; Zhang, Wen; Xiao, Dingquan; Zhu, Jianguo

    2016-07-01

    Bismuth-layered structured ceramics Ca0.85(Li,Ce)0.075Bi4Ti4- x Nb x O15-0.01MnCO3 were prepared by the conventional solid-state reaction method. The evolution of microstructure and corresponding electrical properties were studied. All the samples presented a single bismuth layered-structural phase with m = 4, indicating that (Li, Ce)4+, Nb5+ and Mn2+ adequately enter into the pseudo-perovskite structure and form solid solutions. It was found that Ca0.85(Li,Ce)0.075Bi4Ti3.98Nb0.02O15-0.01MnCO3 (CBTLCM-0.02Nb) ceramics possess the optimum electrical properties. The piezoelectric coefficient d 33, dielectric constant ɛ r, loss tan δ, planar electromechanical coupling factor k p and Curie-temperature T C of CBTLCM-0.02Nb ceramics were found to be ˜19.6 pC/N, 160, 0.16%, 8.1% and 767°C, respectively. Furthermore, the thermal depoling behavior demonstrates that the d 33 value of x = 0.02 content remains at 16.8 pC/N after annealing at 500°C. These results suggest that the (Li, Ce)4+-, Nb5+- and Mn2+-doped CBT-based ceramics are promising candidates for high-temperature piezoelectric applications.

  8. Multiple Loops of the Dihydropyridine Receptor Pore Subunit Are Required for Full-Scale Excitation-Contraction Coupling in Skeletal Muscle

    PubMed Central

    Carbonneau, Leah; Bhattacharya, Dipankar; Sheridan, David C.; Coronado, Roberto

    2005-01-01

    Understanding which cytosolic domains of the dihydropyridine receptor participate in excitation-contraction (EC) coupling is critical to validate current structural models. Here we quantified the contribution to skeletal-type EC coupling of the α1S (CaV1.1) II-III loop when alone or in combination with the rest of the cytosolic domains of α1S. Chimeras consisting of α1C (CaV1.2) with α1S substitutions at each of the interrepeat loops (I-II, II-III, and III-IV loops) and N- and C-terminal domains were evaluated in dysgenic (α1S-null) myotubes for phenotypic expression of skeletal-type EC coupling. Myotubes were voltage-clamped, and Ca2+ transients were measured by confocal line-scan imaging of fluo-4 fluorescence. In agreement with previous results, the α1C/α1S II-III loop chimera, but none of the other single-loop chimeras, recovered a sigmoidal fluorescence-voltage curve indicative of skeletal-type EC coupling. To quantify Ca2+ transients in the absence of inward Ca2+ current, but without changing the external solution, a mutation, E736K, was introduced into the P-loop of repeat II of α1C. The Ca2+ transients expressed by the α1C(E736K)/α1S II-III loop chimera were ∼70% smaller than those expressed by the Ca2+-conducting α1C/α1S II-III variant. The low skeletal-type EC coupling expressed by the α1C/α1S II-III loop chimera was confirmed in the Ca2+-conducting α1C/α1S II-III loop variant using Cd2+ (10−4 M) as the Ca2+ current blocker. In contrast to the behavior of the II-III loop chimera, Ca2+ transients expressed by an α1C/α1S chimera carrying all tested skeletal α1S domains (all α1S interrepeat loops, N- and C-terminus) were similar in shape and amplitude to wild-type α1S, and did not change in the presence of the E736K mutation or in the presence of 10−4 M Cd2+. Controls indicated that similar dihydropyridine receptor charge movements were expressed by the non-Ca2+ permeant α1S(E1014K) variant, the α1C(E736K)/α1S II-III loop chimera, and the α1C(E736K)/α1S chimera carrying all tested α1S domains. The data indicate that the functional recovery produced by the α1S II-III loop is incomplete and that multiple cytosolic domains of α1S are necessary for a quantitative recovery of the EC-coupling phenotype of skeletal myotubes. Thus, despite the importance of the II-III loop there may be other critical determinants in α1S that influence the efficiency of EC coupling. PMID:15849247

  9. Role of TRPC1 channel in skeletal muscle function

    PubMed Central

    Zanou, Nadège; Shapovalov, Georges; Louis, Magali; Tajeddine, Nicolas; Gallo, Chiara; Van Schoor, Monique; Anguish, Isabelle; Cao, My Linh; Schakman, Olivier; Dietrich, Alexander; Lebacq, Jean; Ruegg, Urs; Roulet, Emmanuelle; Birnbaumer, Lutz

    2010-01-01

    Skeletal muscle contraction is reputed not to depend on extracellular Ca2+. Indeed, stricto sensu, excitation-contraction coupling does not necessitate entry of Ca2+. However, we previously observed that, during sustained activity (repeated contractions), entry of Ca2+ is needed to maintain force production. In the present study, we evaluated the possible involvement of the canonical transient receptor potential (TRPC)1 ion channel in this entry of Ca2+ and investigated its possible role in muscle function. Patch-clamp experiments reveal the presence of a small-conductance channel (13 pS) that is completely lost in adult fibers from TRPC1−/− mice. The influx of Ca2+ through TRPC1 channels represents a minor part of the entry of Ca2+ into muscle fibers at rest, and the activity of the channel is not store dependent. The lack of TRPC1 does not affect intracellular Ca2+ concentration ([Ca2+]i) transients reached during a single isometric contraction. However, the involvement of TRPC1-related Ca2+ entry is clearly emphasized in muscle fatigue. Indeed, muscles from TRPC1−/− mice stimulated repeatedly progressively display lower [Ca2+]i transients than those observed in TRPC1+/+ fibers, and they also present an accentuated progressive loss of force. Interestingly, muscles from TRPC1−/− mice display a smaller fiber cross-sectional area, generate less force per cross-sectional area, and contain less myofibrillar proteins than their controls. They do not present other signs of myopathy. In agreement with in vitro experiments, TRPC1−/− mice present an important decrease of endurance of physical activity. We conclude that TRPC1 ion channels modulate the entry of Ca2+ during repeated contractions and help muscles to maintain their force during sustained repeated contractions. PMID:19846750

  10. 78 FR 7425 - Combined Notice of Filings #1

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... Allegheny LLC, BE CA LLC, BE Ironwood LLC, BE KJ LLC, BE Louisiana LLC, BE Rayle LLC, Cedar Brakes I, L.L.C., Cedar Brakes II, L.L.C., Central Power & Lime LLC, Triton Power Michigan LLC, Utility Contract Funding... that the Commission received the following electric rate filings: Docket Numbers: ER10-1707-002; ER11...

  11. Dachiardite-K, (K2Ca)(Al4Si20O48) · 13H2O, a new zeolite from Eastern Rhodopes, Bulgaria

    NASA Astrophysics Data System (ADS)

    Chukanov, N. V.; Encheva, S.; Petrov, P.; Pekov, I. V.; Belakovskiy, D. I.; Britvin, S. N.; Aksenov, S. M.

    2016-12-01

    Dachiardite-K (IMA No. 2015-041), a new zeolite, is a K-dominant member of the dachiardite series with the idealized formula (K2Ca)(Al4Si20O48) · 13H2O. It occurs in the walls of opal-chalcedony veinlets cutting hydrothermally altered effusive rocks of the Zvezdel paleovolcanic complex near the village of Austa, Momchilgrad Municipality, Eastern Rhodopes, Bulgaria. Chalcedony, opal, dachiardite-Ca, dachiardite-Na, ferrierite-Mg, ferrierite-K, clinoptilolite-Ca, clinoptilolite-K, mordenite, smectite, celadonite, calcite, and barite are associated minerals. The mineral forms radiated aggregates up to 8 mm in diameter consisting of split acicular individuals. Dachiardite-K is white to colorless. Perfect cleavage is observed on (100). D meas = 2.18(2), D calc = 2.169 g/cm3. The IR spectrum is given. Dachiardite-K is biaxial (+), α = 1.477 (calc), β = 1.478(2), γ = 1.481(2), 2 V meas = 65(10)°. The chemical composition (electron microprobe, mean of six point analyses, H2O determined by gravimetric method) is as follows, wt %: 4.51 K2O, 3.27 CaO, 0.41 BaO, 10.36 A12O3, 67.90 SiO2, 13.2 H2O, total is 99.65. The empirical formula is H26.23K1.71Ca1.04Ba0.05Al3.64Si20.24O61. The strongest reflections in the powder X-ray diffraction pattern [ d, Å (I, %) (hkl)] are: 9.76 (24) (001), 8.85 (58) (200), 4.870 (59) (002), 3.807 (16) (202), 3.768 (20) (112, 020), 3.457 (100) (220), 2.966 (17) (602). Dachiardite-K is monoclinic, space gr. C2/m, Cm or C2; the unit cell parameters refined from the powder X-ray diffraction data are: a = 18.670(8), b = 7.511(3), c = 10.231(4) Å, β = 107.79(3)°, V= 1366(1) Å3, Z = 1. The type specimen has been deposited in the Earth and Man National Museum, Sofia, Bulgaria, with the registration number 23927.

  12. Effects of protopine on intracellular calcium and the PKC activity of rat aorta smooth muscle.

    PubMed

    Li, Bin; Wu, Qin; Shi, Jing-Shan; Sun, An-Sheng; Huang, Xie-Nan

    2005-04-25

    We have previously shown that the vasodilator effect of protopine (Pro) on rabbit aorta is related to the elevations of cAMP and cGMP. In the present study, the vasodilator mechanisms of Pro were further explored by recording the isotonic contraction of the rat aortic strips, detecting directly the intracellular free Ca(2+) concentration ([Ca(2+)](i)) with Fura-2/AM loaded vascular smooth muscle cells (VSMCs) of rat aorta, and determining the activity of protein kinase C (PKC) in rat aortic tissue with radioactive isotope gamma-32P -ATP-catalyzing assay. By recording the aortic strips contraction induced by noradrenaline (NA) and high potassium (K(+)), Pro shifted nonparallelly the concentration-response curves of NA and high K(+) to right, in which the maximal response was depressed in the presence of Pro (30 and 100 micromol/L), and the values of pD'(2) were 3.70-/+0.25 and 3.97-/+0.15 for NA and high K(+), respectively. In the Fura-2/AM loaded VSMCs, Pro (50 and 100 micromol/L) could not produce any significant change on the resting [Ca(2+)](i), but significantly decreased the [Ca(2+)](i) elevated by NA and high K(+). Pro (30 and 100 micromol/L) had no significant effect on the activity of the cytosolic and membrane PKC in the aortic strips inpretreated by NA. However, in the aortic strips pretreated by NA, the activity of membrane PKC was significantly increased and the activity of cytosolic PKC tended to be decreased by Pro, while the activity of total PKC did not change. These results suggest that Pro seems to promote the translocation of PKC from the cytosol to the membrane in the presence of NA, its vasodilator effect may be the comprehensive result of its decreasing effect on the [Ca(2+)](i) and the increasing effect on cAMP and cGMP, as well as its influence on the PKC.

  13. Monoamine Oxidase A: A Novel Target for Progression and Metastasis of Prostate Cancer

    DTIC Science & Technology

    2015-12-01

    dye* Corresponding author. Uro -Oncology Research Pr Center, 8750 Beverly Blvd., Atrium 103, Los Angeles, E-mail address: Leland.Chung@cshs.org (L.W.K...INVESTIGATOR: Jean C. Shih, Ph.D. CONTRACTING ORGANIZATION: University of Southern California Los Angeles, CA 90089-0001 REPORT DATE: December 2015...SOUTHERN CALIFORNIA 3720 S. FLOWER STREET LOS ANGELES, CA 90089-0001 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S

  14. 9433 Design Pointing Anomaly. Volume II. Appendices

    DTIC Science & Technology

    1976-01-30

    CALIFORNIA 90278 This final report was submitted by TRW Defense and Space t) Systems Group, One Space Park, Redondo Beach, CA 90278, under Contract F04701-75...C-0257, with the Space and Missile Systems Organization, Deputy for Space Communications Systems , P.O. Box 92960, Worldway Postal Center, Los Angeles...CA 90009. Captain G. D. Nordley, SAMSO/SKD, was the Projcect Officer for Space Communications Systems . This report has been reviewed by the

  15. Novel insights on the relationship between T-tubular defects and contractile dysfunction in a mouse model of hypertrophic cardiomyopathy.

    PubMed

    Crocini, C; Ferrantini, C; Scardigli, M; Coppini, R; Mazzoni, L; Lazzeri, E; Pioner, J M; Scellini, B; Guo, A; Song, L S; Yan, P; Loew, L M; Tardiff, J; Tesi, C; Vanzi, F; Cerbai, E; Pavone, F S; Sacconi, L; Poggesi, C

    2016-02-01

    Abnormalities of cardiomyocyte Ca(2+) homeostasis and excitation-contraction (E-C) coupling are early events in the pathogenesis of hypertrophic cardiomyopathy (HCM) and concomitant determinants of the diastolic dysfunction and arrhythmias typical of the disease. T-tubule remodelling has been reported to occur in HCM but little is known about its role in the E-C coupling alterations of HCM. Here, the role of T-tubule remodelling in the electro-mechanical dysfunction associated to HCM is investigated in the Δ160E cTnT mouse model that expresses a clinically-relevant HCM mutation. Contractile function of intact ventricular trabeculae is assessed in Δ160E mice and wild-type siblings. As compared with wild-type, Δ160E trabeculae show prolonged kinetics of force development and relaxation, blunted force-frequency response with reduced active tension at high stimulation frequency, and increased occurrence of spontaneous contractions. Consistently, prolonged Ca(2+) transient in terms of rise and duration are also observed in Δ160E trabeculae and isolated cardiomyocytes. Confocal imaging in cells isolated from Δ160E mice reveals significant, though modest, remodelling of T-tubular architecture. A two-photon random access microscope is employed to dissect the spatio-temporal relationship between T-tubular electrical activity and local Ca(2+) release in isolated cardiomyocytes. In Δ160E cardiomyocytes, a significant number of T-tubules (>20%) fails to propagate action potentials, with consequent delay of local Ca(2+) release. At variance with wild-type, we also observe significantly increased variability of local Ca(2+) transient rise as well as higher Ca(2+)-spark frequency. Although T-tubule structural remodelling in Δ160E myocytes is modest, T-tubule functional defects determine non-homogeneous Ca(2+) release and delayed myofilament activation that significantly contribute to mechanical dysfunction. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. [The relevance of the trace elements zinc and iron in the milk fever disease of cattle].

    PubMed

    Heilig, M; Bäuml, D; Fürll, M

    2014-01-01

    The aim of this study was to analyse the concentrations of Zn and Fe as well as their relationships to metabolic parameters in milk fever cows. A total of 195 Simmental cows, downer cows and clinically healthy control animals were divided into five groups: a) control group (CG, n = 21), b) all cows with milk fever (MF) (n = 174), c) MF cows without additional diseases (n = 145), d) cows with MF and mastitis (n = 10) and e) cows with retained placenta or endometritis (n = 19). Selenium (Se), zinc (Zn), iron (Fe), calcium (Ca), inorganic phosphorus (Pi), tumour necrosis factor α (TNFα), haptoglobin (Hp), antioxidants (Trolox Equivalent Antioxidative Capacity: TEAC), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), bilirubin, urea, creatinine, glucose, cholesterol, gamma-glutamyl transferase (GGT) and alkaline phosphatase (AP) were analysed in the blood serum. The concentrations of Zn, Fe, Ca, Pi and TEAC were lower in groups b) to e) whereas Hp was higher than in the CG (p ≤ 0.05). In group c), lower Ca and Pi concentrations were found when compared to groups d) and e) (p ≤ 0.05). In group e), Zn concentrations were significantly lower than in group c) (p ≤ 0.05). Zn was negatively correlated with K (CG) and positively correlated with TEAC, Cu, Mn and Fe (groups b and c) and with Mn (group e) (p ≤ 0.05). Fe was positively correlated with Ca (group c), Pi (group c), K (groups b and c) and Mg (groups b-d) as well as with Zn, Cu and Se (groups b and c) (p ≤ 0.05). In groups b) and c), TNFα was increased and negatively correlated with Fe (p ≤ 0.05). AP activity in groups b) and e) was lower than in the CG (p ≤ 0.05). These results and literature data support the hypothesis that Zn and Fe could be engaged in bone metabolism and be involved in the pathogenesis of MF. The concentrations of Hp and TEAC support this interpretation. Control of the Zn and Fe status of cows and Zn supplementation should be included in the prevention and advanced therapy of MF.

  17. Impaired micturition reflex caused by acute selective dorsal or ventral root(s) rhizotomy in anesthetized rats.

    PubMed

    Liao, Jiuan-Miaw; Cheng, Chen-Li; Lee, Shin-Da; Chen, Gin-Den; Chen, Kuo-Jung; Yang, Chao-Hsun; Pan, Shwu-Fen; Chen, Mei-Jung; Huang, Pei-Chen; Lin, Tzer-Bin

    2006-01-01

    To clarify the contributions of parasympathetic inputs and outputs to the micturition reflex. Intra-vesical pressure (IVP), external urethral sphincter electromyogram (EMG), pelvic afferent nerve activities (PANA), and pelvic efferent nerve activities (PENA) as well as the time-derived IVP (dIVP, an index of bladder contractility) were evaluated in intact and acute dorsal or ventral root(s) rhizotomized (DRX and VRX, respectively) rats. In DRX rats, when compared with that in intact stage, the voiding frequency was decreased (75 +/- 15% of intact, P < 0.05, n = 8), while the threshold pressure to trigger voiding contractions was significantly increased (187 +/- 75% of intact, P < 0.05, n = 8). In addition, several insufficient contractions (5.3 +/- 3.5 contractions/voiding, P < 0.05, n = 8) occurred in ahead of each voiding contraction. On the other hand, in VRX rats, the peak and rebound IVP were significantly decreased (90 +/- 3.5% and 75 +/- 11.3% of intact, P < 0.01, n = 8), while the threshold pressure was not affected (102 +/- 11% of intact, P = NS, n = 8). The time-derived parameters were significantly decreased in VRX (peak dIVP, 78 +/- 10.2%, rebound dIVP, 75 +/- 15.6%, minimal dIVP, 68 +/- 14% of intact, P < 0.01, n = 8) but only peak dIVP was decreased (85 +/- 11% of intact, P < 0.01, n = 8) in DRX rats. Acute selective DRX and VRX rat can be an animal model to investigate peripheral neural control in micturition functions.

  18. Inhibitory mechanism of monensin on high K+-induced contraction in guniea-pig urinary bladder.

    PubMed

    Kaneda, Takeharu; Takeuchi, Mayumi; Shimizu, Kazumasa; Urakawa, Norimoto; Nakajyo, Shinjiro; Mochizuki-Kobayashi, Mariko; Ueda, Fukiko; Hondo, Ryo

    2006-02-01

    In this study, we examined the inhibitory mechanism of monensin on high K+-induced contraction in guinea-pig urinary bladder. The relaxant effect of monensin (0.001 - 10 microM) was more potent than those of NaCN (100 microM - 1 mM) and forskolin (3 - 10 microM). Monensin (0.1 microM), NaCN (300 microM), or forskolin (10 microM) inhibited high K+-induced contraction without decreasing [Ca2+]i level. Monensin and NaCN remarkably decreased creatine phosphate and ATP contents. Monensin and NaCN inhibited high K+-induced increases in flavoprotein fluorescence, which is involved in mitochondrial respiration. Forskolin increased cAMP content but monensin did not. Monensin increased Na+ content at 10 microM but not at 0.1 microM that induced maximum relaxation. In the alpha-toxin-permeabilized muscle, forskolin significantly inhibited the Ca2+-induced contraction, but monensin did not affect it. These results suggest that the relaxation mechanism of monensin in smooth muscle of urinary bladder may be an inhibition of oxidative metabolism.

  19. Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

    PubMed Central

    Hollingworth, Stephen

    2012-01-01

    In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller. PMID:22450485

  20. 48 CFR 217.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...)(i) Notwithstanding FAR 17.204(e), the ordering period of a task order or delivery order contract...) of this section does not apply to the following: (A) Contracts, including task or delivery order contracts, awarded under other statutory authority. (B) Advisory and assistance service task order contracts...

  1. Influence of hormone supplementation to extended semen on artificial insemination, uterine contractions, establishment of a sperm reservoir, and fertility in swine.

    PubMed

    Willenburg, K L; Miller, G M; Rodriguez-Zas, S L; Knox, R V

    2003-04-01

    This study was performed to quantify the effect of hormone addition to semen using a low-fertility model to evaluate its effectiveness and mode of action. At 24 h after the onset of estrus, all gilts received a single low-dose AI (0.5 x 10(9) sperm/80 mL) with no hormone (control, C), estrogens (E, 11.5 microg), PGF2alpha (PG, 5 mg of Lutalyse), or oxytocin (OT, 4 IU), which were then evaluated for semen backflow (n = 48), oviductal and uterine sperm numbers (n = 28), uterine contractions (n = 12), pregnancy rate (PR, n = 120), and number of fetuses (n = 67). In Exp. 1, backflow of semen from the uterus was collected for 8 h after AI, whereas PR and fetuses were assessed at d 25 to 30 after AI. In Exp. 2, backflow was collected and reproductive tracts flushed to determine sperm numbers in the oviducts and the anterior segments of the uterus. In Exp. 3, sows were monitored for uterine contractions for 1 h before AI and for 2 h after AI. In Exp. 1, there was a treatment x time interaction for fluid loss (P < 0.001), but by 8 h after AI, there was no difference in the total volume (70 +/- 1 mL) of semen lost between hormone treatments (85%) compared to controls (90%). There was also a treatment x time interaction (P < 0.05) for number of sperm lost in the backflow (2.1 +/- 0.1 x 10(8)), but by 8 h following AI, there was no effect on total sperm lost for the hormone treatments (38%) compared to C (54%). There was a trend (P = 0.10) for increased numbers of sperm in the uteri of hormone-treated gilts (6.0 +/- 1.3 x 10(4)) compared with C gilts (2.2 +/- 1.3 x 10(4), but there was no effect of treatment on sperm numbers in the oviducts (3.2 +/- 1.3 x 10(4)). Within 0.5 h of AI, there was an increase in the frequency of contractions for PG compared with the other treatments (14.2 vs. 6.3/h, P < 0.005), however there was no effect on amplitude (54 mmHg) or duration (35 s) of contractions. The PR was not influenced by treatment and averaged 54% (P > 0.60), but total numbers of healthy fetuses were increased (P < 0.04) by PG (8.7) and tended (P = 0.06) to be increased for OT (8.4), but not for E (7.2) compared to C (5.8). Hormone addition to semen increased numbers of fetuses and this may be related to an alteration in the pattern of fluid and sperm loss after AI and a tendency for increased numbers of sperm in the anterior segment of the uterus. Therefore, in situations of lowered fertility, hormone addition could be a strategy to limit infertility in swine.

  2. Exploring the mechanism of action of the sperm-triggered calcium-wave pacemaker in ascidian zygotes.

    PubMed

    Carroll, Michael; Levasseur, Mark; Wood, Chris; Whitaker, Michael; Jones, Keith T; McDougall, Alex

    2003-12-15

    In ascidians, as in mammals, sperm trigger repetitive Ca2+-waves that originate from cortical pacemakers situated in the vegetal hemisphere of the zygotes. In ascidians, a vegetal protrusion termed the contraction pole (CP) acts as the Ca2+-wave pacemaker, but the mechanism that underlies the generation of a Ca2+-wave pacemaker is not known. Here, we tested four hypotheses to determine which factors at the CP are involved in setting the pace of the ascidian Ca2+-wave pacemaker: (1) localized Ca2+ influx; (2) accumulation of phosphatidylinositol (4,5)bisphosphate [PtdIns(4,5)P2]; (3) accumulation of cortical endoplasmic reticulum (cER); and (4) enrichment of the sperm activating factor. We developed a method of dynamically monitoring the location of the CP during fertilization using a plekstrin homology (PH) domain from phospholipase Cdelta1 coupled to green fluorescent protein (GFP) that binds PtdIns(4,5)P2. We found that eggs in Ca2+-free sea water displayed Ca2+ waves that originated from the CP, showing that enhanced CP Ca2+ influx does not determine the origin of the pacemaker. Also, disruption of the PH::GFP-labelled CP once it had formed did not dislodge the Ca2+-wave pacemaker from that site. Next, when we prevented the accumulation of cER at the CP, all of the Ca2+ waves came from the site of sperm-egg fusion and the frequency of Ca2+ oscillations was unaltered. These data show that local Ca2+ influx, the accumulation of PtdIns(4,5)P2 and cER at the CP are not required for Ca2+-wave pacemaker function and instead suggest that a factor associated with the sperm determines the site of the Ca2+-wave pacemaker. Finally, when we injected ascidian sperm extract into the centre of unfertilized ascidian eggs that had been treated with microfilament- and microtubule-disrupting drugs, all the Ca2+ waves still originated from near the plasma membrane, showing that the sperm factor does not require an intact cortex if it is enriched near the plasma membrane (PM). We suggest that the Ca2+-releasing sperm factor might be tethered near or on the PM and that following the cortical contraction, it is translocated to the vegetal CP, thus making that site act as a Ca2+-wave pacemaker.

  3. Enhanced pyruvate dehydrogenase activity improves cardiac outcomes in a murine model of cardiac arrest.

    PubMed

    Piao, Lin; Fang, Yong-Hu; Kubler, Manfred M; Donnino, Michael W; Sharp, Willard W

    2017-01-01

    Post-ischemic changes in cellular metabolism alter myocardial and neurological function. Pyruvate dehydrogenase (PDH), the limiting step in mitochondrial glucose oxidation, is inhibited by increased expression of PDH kinase (PDK) during ischemia/reperfusion injury. This results in decreased utilization of glucose to generate cellular ATP. Post-cardiac arrest (CA) hypothermia improves outcomes and alters metabolism, but its influence on PDH and PDK activity following CA are unknown. We hypothesized that therapeutic hypothermia (TH) following CA is associated with the inhibition of PDK activity and increased PDH activity. We further hypothesized that an inhibitor of PDK activity, dichloroacetate (DCA), would improve PDH activity and post-CA outcomes. Anesthetized and ventilated adult female C57BL/6 wild-type mice underwent a 12-minute KCl-induced CA followed by cardiopulmonary resuscitation. Compared to normothermic (37°C) CA controls, administering TH (30°C) improved overall survival (72-hour survival rate: 62.5% vs. 28.6%, P<0.001), post-resuscitation myocardial function (ejection fraction: 50.9±3.1% vs. 27.2±2.0%, P<0.001; aorta systolic pressure: 132.7±7.3 vs. 72.3±3.0 mmHg, P<0.001), and neurological scores at 72-hour post CA (9.5±1.3 vs. 5.4±1.3, P<0.05). In both heart and brain, CA increased lactate concentrations (1.9-fold and 3.1-fold increase, respectively, P<0.01), decreased PDH enzyme activity (24% and 50% reduction, respectively, P<0.01), and increased PDK protein expressions (1.2-fold and 1.9-fold, respectively, P<0.01). In contrast, post-CA treatment with TH normalized lactate concentrations (P<0.01 and P<0.05) and PDK expressions (P<0.001 and P<0.05), while increasing PDH activity (P<0.01 and P<0.01) in both the heart and brain. Additionally, treatment with DCA (0.2 mg/g body weight) 30 min prior to CA improved both myocardial hemodynamics 2 hours post-CA (aortic systolic pressure: 123±3 vs. 96±4 mmHg, P<0.001) and 72-hour survival rates (50% vs. 19%, P<0.05) in normothermic animals. Enhanced PDH activity in the setting of TH or DCA administration is associated with improved post-CA resuscitation outcomes. PDH is a promising therapeutic target for improving post-CA outcomes.

  4. Prefrontal Dopamine D1 Receptors and Working Memory in Schizotypal Personality Disorder: A PET Study with [11C]NNC112

    PubMed Central

    Thompson, Judy L.; Rosell, Daniel R.; Slifstein, Mark; Girgis, Ragy R.; Xu, Xiaoyan; Ehrlich, Yosefa; Kegeles, Lawrence S.; Hazlett, Erin A.; Abi-Dargham, Anissa; Siever, Larry J.

    2014-01-01

    Rationale Schizotypal personality disorder (SPD) is associated with working memory (WM) impairments that are similar to those observed in schizophrenia. Imaging studies have suggested that schizophrenia is associated with alterations in dopamine D1-receptor availability in the prefrontal cortex (PFC) that may be related to the WM impairments that characterize this disorder. Objectives To characterize prefrontal D1-receptor availability and its relation to WM performance in SPD. Methods We used positron emission tomography (PET) and the radiotracer [11C]NNC112 with 18 unmedicated SPD and 21 healthy-control participants; as an index of D1-receptor availability, binding-potential (BP) measures (BPF, BPND, and BPP) were calculated for prefrontal and striatal subregions. To assess WM, SPD participants completed the 2-back and Paced Auditory Serial Addition Test (PASAT). Results There were no significant group differences in PFC BP. BPF and BPP in the medial PFC were significantly negatively related to PASAT performance (rs=-0.551, p=.022 and rs=-0.488, p=.047, respectively), but BP was not related to 2-back performance. Conclusions In contrast to what has been found in schizophrenia, SPD was not associated with significant prefrontal D1-receptor alterations. Similar to previous schizophrenia findings, however, higher prefrontal D1-receptor availability was associated with poorer WM performance (as measured by the PASAT) in SPD. These findings suggest that schizophrenia and SPD may share a common pathophysiological feature related to prefrontal dopamine functioning that contributes to WM dysfunction, but that in SPD, alterations in D1 may occur only in a subset of individuals and/or to an extent that is minor relative to what occurs in schizophrenia. PMID:24781514

  5. All Prime Contract Awards by State or Country, Place, and Contractor, FY 84. Part 7 (Aberdeen, Maryland - Wrentham, Massachusetts).

    DTIC Science & Technology

    1984-01-01

    0 C D CaDOC 00 CD001 00 0001 CD0DD 0 00ac 0C D DC 00 00 0D000000 Li wi W z LU~ wi 2: Li Li w Li Li 010t - 0a ca 0 0a o 0 0o to m 0n 0 GaO -a r NN 00...0 0N0 -C) ’ N J0 󈧄-m-3m (fl (a) (N0I- c))0- * ~ c 0 ’a I ~ 0 00 -1 -.1 -1 -j 0 000L000 00 00 I 0 (0)-1 CuaC fr aCD L z 0 Ca CD C 0 0 0 0 GaO -a C3...L ,0, O O 0 U’in) Jini t 30 OD0N Of N MN cr V)() វI 1 (D .0 >- 0 ) W - D~ Di 0- 0y >wO 0 000 c- coNC- C- Q)- - - ZN 0M F-N 1-- 9-OI - 0 - 0 - a0

  6. Joint-Base Contracting: A Comparative Analysis of Joint-Base Contracting Activities Between Services

    DTIC Science & Technology

    2011-11-09

    NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND...rpfkbpp=C=mr_if`=mlif`v= = - 1 - k^s^i=mlpqdo^ar^qb=p`elli= I. Introduction A. Overview The idea of consolidating functions is not new in the corporate ...gain economies of scale, and combining the experience and skill of multiple organizations to improve corporate knowledge. The automobile industry has

  7. 41 CFR 102-85.95 - Who pays for the TI allowance?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Who pays for the TI allowance? 102-85.95 Section 102-85.95 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR OCCUPANCY IN...

  8. 41 CFR 102-85.140 - How are changes in Rent reflected in OAs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false How are changes in Rent reflected in OAs? 102-85.140 Section 102-85.140 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85-PRICING POLICY FOR...

  9. 41 CFR 102-85.50 - When does availability of funding have to be certified?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false When does availability of funding have to be certified? 102-85.50 Section 102-85.50 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85...

  10. 41 CFR 102-85.50 - When does availability of funding have to be certified?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false When does availability of funding have to be certified? 102-85.50 Section 102-85.50 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 85...

  11. 41 CFR 102-85.120 - What is shell Rent?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is shell Rent? 102-85.120 Section 102-85.120 Public Contracts and Property Management Federal Property Management... GSA SPACE Rent Charges § 102-85.120 What is shell Rent? Shell Rent is that portion of GSA Rent charged...

  12. 41 CFR 102-85.120 - What is shell Rent?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What is shell Rent? 102-85.120 Section 102-85.120 Public Contracts and Property Management Federal Property Management... GSA SPACE Rent Charges § 102-85.120 What is shell Rent? Shell Rent is that portion of GSA Rent charged...

  13. Potassium Channels in Regulation of Vascular Smooth Muscle Contraction and Growth

    PubMed Central

    Jackson, William F.

    2017-01-01

    Potassium channels importantly contribute to the regulation of vascular smooth muscle (VSM) contraction and growth. They are the dominant ion conductance of the VSM cell membrane and importantly determine and regulate membrane potential. Membrane potential, in turn, regulates the open-state probability of voltage-gated Ca2+ channels (VGCC), Ca2+ influx through VGCC, intracellular Ca2+ and VSM contraction. Membrane potential also affects release of Ca2+ from internal stores and the Ca2+ sensitivity of the contractile machinery such that K+ channels participate in all aspects of regulation of VSM contraction. Potassium channels also regulate proliferation of VSM cells through membrane potential-dependent and membrane potential-independent mechanisms. Vascular smooth muscle cells express multiple isoforms of at least five classes of K+ channels contribute to the regulation of contraction and cell proliferation (growth). This review will examine the structure, expression and function of large-conductance, Ca2+-activated K+ (BKCa) channels, intermediate-conductance Ca2+-activated K+ (KCa3.1) channels, multiple isoforms of voltage-gated K+ (KV) channels, ATP-sensitive K+ (KATP) channels, and inward-rectifier K+ (KIR) channels in both contractile and proliferating VSM cells. PMID:28212804

  14. Evaluation of serum CA27.29, CA15-3 and CEA in patients with breast cancer.

    PubMed

    Hou, M F; Chen, Y L; Tseng, T F; Lin, C M; Chen, M S; Huang, C J; Huang, Y S; Hsieh, J S; Huang, T J; Jong, S B; Huang, Y F

    1999-09-01

    The Truquant BR radioimmunoassay (RIA) using monoclonal antibody BR 27.29 to recognize a peptide sequence on the MUC-1 gene product for quantification of the CA 27.29 antigen in serum was used in this report to evaluate in 145 patients with breast cancer and compared the other conventional serum markers such as CA15-3 and CEA. The upper limit of normal (25 u/ml) was determined from CA27.29 values 12.4 +/- 4.1 u/ml (mean +/- 3 S.D.) for 112 female subjects apparently free of disease. The CA15-3 levels above 25 u/ml and CEA levels above 5 ng/ml were considered positive values. Thirty-seven cases of 145 patients studied had elevated CA 27.29 levels (sensitivity: 25.5%), 35 of 145 had positive CA15-3 levels (sensitivity 24.1%) and 27 of 145 patients had positive CEA levels (sensitivity: 18.6%) (p < 0.05). One hundred and ten cases of the breast cancer patients (75.8%) did not have metastatic disease. In this group CA 27.29 sensitivity was 6.4%, while CA15-3 sensitivity was 5.5% and CEA sensitivity was 4.5% (p > 0.05). Mean values were 10.2 +/- 9.2 u/ml for CA 27.29, 14.1 +/- 5.6 u/ml for CA 15-3 and 1.7 +/- 1.5 ng/ml for CEA. Thirty-five patients (24.2%) had metastatic disease. In this group CA 27.29 sensitivity was 85.7%, CA15-3 sensitivity was 82.8% and CEA sensitivity was 62.8% (p < 0.05). Mean values for CA27.29 was 152.6 +/- 131.6 u/ml, CA15-3 was 123.1 +/- 107.6 u/ml and 21.8 +/- 36.9 ng/ml of CEA. With regard to the correlation of three tumor markers with clinical stages, patients had significantly higher levels of CA27.29 than CEA, but they were similar to CA 15-3 in metastatic breast cancer. These results suggest CA27.29 to be more sensitive and specific than CEA, but that it is similar to CA15-3 for metastatic breast cancer detection and monitoring.

  15. Relaxant effect of proton pump inhibitors on in vitro myometrium from pregnant women.

    PubMed

    Terranova, C; Petrella, C; Improta, G; Severini, C; Signore, F; Damiani, P; Plotti, F; Scarpignato, C; Angioli, R

    2014-02-14

    In this study we investigate in in vitro myometrial tissue samples of pregnant women: (a) the effects of proton pomp inhibitors (PPIs) (omeprazole, esomeprazole, pantoprazole, lansoprazole and rabeprazole) on spontaneous contractions; (b) the muscle-relaxant efficacy of the most active PPI considered (pantoprazole) in comparison with that of other known tocolytics (nifedipine, atosiban, MgSO4, isoxsuprine); (c) the effect of pantoprazole on contractions induced by calcium (Ca(++)), KCl, oxytocin and prostaglandin (PGE2); (d) the possible mediators of pantoprazole relaxant effect. Organ bath studies were performed on myometrial tissue samples (40×10×10 mm) from pregnant women (38-42 weeks of gestational age) undergoing elective caesarian section. All the PPIs studied reduce the spontaneous contraction of the myometrial smooth muscle. Pantoprazole is the most effective and most potent inhibitor among those analyzed. Pantoprazole also reduces the contractions induced by Ca(++), KCl, oxytocin and PGE2. Neither NO, nor PGs, or the activation of Ca(++)-dependent K(+) currents mediate the muscle-relaxant effect of this PPI. These data, together with the fact that PPIs almost do not present side effects, suggest that these drugs can offer new therapeutic strategies for preterm delivery. Undoubtedly, further investigations and clinical studies are necessary before adding PPIs to the list of drugs available for the treatment of preterm delivery. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Prior history of FDI muscle contraction: different effect on MEP amplitude and muscle activity.

    PubMed

    Talis, V L; Kazennikov, O V; Castellote, J M; Grishin, A A; Ioffe, M E

    2014-03-01

    Motor evoked potentials (MEPs) in the right first dorsal interosseous (FDI) muscle elicited by transcranial magnetic stimulation of left motor cortex were assessed in ten healthy subjects during maintenance of a fixed FDI contraction level. Subjects maintained an integrated EMG (IEMG) level with visual feedback and reproduced this level by memory afterwards in the following tasks: stationary FDI muscle contraction at the level of 40 ± 5 % of its maximum voluntary contraction (MVC; 40 % task), at the level of 20 ± 5 % MVC (20 % task), and also when 20 % MVC was preceded by either no contraction (0-20 task), by stronger muscle contraction (40-20 task) or by no contraction with a previous strong contraction (40-0-20 task). The results show that the IEMG level was within the prescribed limits when 20 and 40 % stationary tasks were executed with and without visual feedback. In 0-20, 40-20, and 40-0-20 tasks, 20 % IEMG level was precisely controlled in the presence of visual feedback, but without visual feedback the IEMG and force during 20 % IEMG maintenance were significantly higher in the 40-0-20 task than those in 0-20 and 40-20 tasks. That is, without visual feedback, there were significant variations in muscle activity due to different prehistory of contraction. In stationary tasks, MEP amplitudes in 40 % task were higher than in 20 % task. MEPs did not differ significantly during maintenance of the 20 % level in tasks with different prehistory of muscle contraction with and without visual feedback. Thus, in spite of variations in muscle background activity due to different prehistory of contraction MEPs did not vary significantly. This dissociation suggests that the voluntary maintenance of IEMG level is determined not only by cortical mechanisms, as reflected by corticospinal excitability, but also by lower levels of CNS, where afferent signals and influences from other brain structures and spinal cord are convergent.

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gerthoffer, W.T.; Murphey, K.A.; Khoyi, M.A.

    Previous studies have shown that muscarinic activation of airway smooth muscle in low Ca++ solutions increases myosin phosphorylation without increasing tension. Blocking Ca++ influx reduced phosphorylation, but not to basal levels. It was proposed that release of intracellular Ca++ contributed to dissociation of phosphorylation and contraction. To test this hypothesis the effects of ryanodine were studied under similar conditions. Ryanodine (10(-7) to 10(-5) M) antagonized caffeine-induced contraction of canine tracheal smooth muscle. Ryanodine also reduced carbachol-induced contractions and carbachol-induced myosin phosphorylation. The effect of ryanodine on potassium and serotonin-induced contractions was also investigated to test for a nonspecific inhibitory effect.more » In contrast to the effect on carbachol responses, ryanodine (10(-5) M) potentiated the contractile response to low concentrations of serotonin and potassium, but had no effect on the maximum response to either stimulant. Carbachol (10(-6) M) and ryanodine (10(-5) M) both significantly decreased /sup 45/Ca++ content of tracheal muscle. The effect of ryanodine and carbachol together on /sup 45/Ca++ content was not greater than either drug alone suggesting that ryanodine reduces the caffeine and carbachol responses by depleting releaseable Ca++ stores. Ryanodine significantly reduced Ca++-induced contraction and myosin phosphorylation in carbachol-stimulated muscle, suggesting that some of the Ca++ responsible for elevated phosphorylation is released from the sarcoplasmic reticulum.« less

  18. Thermal Inactivation of Shiga Toxin-Producing Escherichia coli Cells within Cubed Beef Steaks following Cooking on a Griddle.

    PubMed

    Swartz, Richard S; Luchansky, John B; Kulas, Megan; Shoyer, Bradley A; Shane, Laura E; Strasser, Hannah; Munson, Madison; Porto-Fett, Anna C S

    2015-05-01

    Thermal inactivation of Shiga toxin-producing Escherichia coli (STEC) cells within knitted/cubed beef steaks following cooking on a nonstick griddle was quantified. Both faces of each beef cutlet (ca. 64 g; ca. 8.5 cm length by 10.5 cm width by 0.75 cm height) were surface inoculated (ca. 6.6 log CFU/g) with 250 μl of a rifampin-resistant cocktail composed of single strains from each of eight target serogroups of STEC: O26:H11, O45:H2, O103:H2, O104:H4, O111:H(2), O121:H19, O145:NM, and O157:H7. Next, inoculated steaks were (i) passed once through a mechanical tenderizer and then passed one additional time through the tenderizer perpendicular to the orientation of the first pass (single cubed steak; SCS) or (ii) passed once through a mechanical tenderizer, and then two tenderized cutlets were knitted together by passage concomitantly through the tenderizer two additional times perpendicular to the orientation of the previous pass (double cubed steak; DCS). SCS and DCS were individually cooked for up to 3.5 min per side in 30 ml of extra virgin olive oil heated to 191.5°C (376.7°F) on a hard-anodized aluminum nonstick griddle using a flat-surface electric ceramic hot plate. Regardless of steak preparation (i.e., single versus double cubed steaks), as expected, the longer the cooking time, the higher the final internal temperature, and the greater the inactivation of STEC cells within cubed steaks. The average final internal temperatures of SCS cooked for up 2.5 min and DCS cooked for up to 3.5 min ranged from 59.8 to 94.7°C and 40.3 to 82.2°C, respectively. Cooking SCS and DCS on an aluminum griddle set at ca. 191.5°C for 0.5 to 2.5 min and 1.0 to 3.5 min per side, respectively, resulted in total reductions in pathogen levels of ca. 1.0 to ≥6.8 log CFU/g. These data validated that cooking SCS (ca. 0.6 cm thick) or DCS (ca. 1.3 cm thick) on a nonstick aluminum griddle heated at 191.5°C for at least 1.25 and 3.0 min per side, respectively, was sufficient to achieve a 5.0log reduction in the levels of the single strains from each of the eight target STEC serogroups tested.

  19. Relaxant effects of butylidenephthalide in isolated dog blood vessels.

    PubMed

    Ko, Wun Chang; Liao, Chao-Chiun; Shih, Chih-Hsien; Lei, Chien-Bang; Chen, Chi-Ming

    2002-11-01

    We investigated the reason why butylidenephthalide (Bdph) can have an antianginal effect without changing blood pressure in conscious rats. Isolated dog coronary artery (CA), femoral vein (FV), femoral artery (FA), and mesenteric artery (MA) were used to evaluate the relaxant effects of Bdph. Bdph concentration-dependently relaxed isolated CA, FV, FA, and MA precontracted by KCl (60 mM) and phenylephrine (phe, 5 microM) with the exception that CA was precontracted by prostaglandin F 2 alpha (PGF 2 alpha, 2 microM) instead of phe. The potency order of Bdph to these blood vessels was FV > CA > FA > or = MA. Bdph also concentration-dependently and non-competitively inhibited cumulative KCl (5 - 120 mM)- and phe (0.1 - 100 microM)-induced contractions in normal, and inhibited cumulative Ca 2+-induced contractions in depolarized blood vessels. The potency order of Bdph to these blood vessels was FV congruent with CA > FA congruent with MA. Bdph (0.02 - 0.04 mM) concentration-dependently and leftward-shifted the log concentration-response curves in parallel and significantly increased the pD 2 value of forskolin, but not nitroprusside in FV. Bdph (0.1 mM) did both in CA. Bdph (0.225 - 0.45 mM) did the opposite to that of nitroprusside, but not forskolin, in FA. Bdph (0.45 - 0.9 mM) did neither in MA. Bdph (0.1 - 1 mM) significantly inhibited cAMP- but not cGMP-PDE activities in these four blood vessels, suggesting that Bdph more selectively inhibited the former in these tissues. The above results suggest that the higher potencies of Bdph on FV and CA than on FA and MA, may be interpreted as the reason why Bdph is useful in the treatment of angina pectoris without changing blood pressure, after Bdph administration in vivo, because the venoreturn may be reduced and the coronary flow may be increased without affecting the arterioles, such as MA, the main determinant of blood pressure. Abbreviations. Bdph:butylidenephthalide Phe:phenylephrine PGF 2alpha :prostaglandin F 2alpha CA:coronary artery FV:femoral vein FA:femoral artery MA:mesenteric artery cAMP:adenosine 3',5'-cyclic monophosphate cGMP:guanosine 3',5'-cyclic monophosphate PDE:phosphodiesterase

  20. The investigation of genetic polymorphisms in the carbonic anhydrase VI gene exon 2 and salivary parameters in type 2 diabetic patients and healthy adults.

    PubMed

    Koç Öztürk, Leyla; Ulucan, Korkut; Akyüz, Serap; Furuncuoğlu, Halit; Bayer, Hikmet; Yarat, Ayşen

    2012-05-01

    The aim of this study was to investigate carbonic anhydrase (CA) VI Exon 2 single nucleotide polymorphism (SNP) and its possible association with salivary parameters in type 2 diabetic patients compared to healthy adults. Caries status was measured by using the DMFT (number of decayed, missing, and filled teeth) index. Unstimulated whole saliva and blood samples were taken. SNPs of CA gene exon 2 were determined by PCR and DNA sequencing. Salivary CA activity and buffering capacity were determined by the method of Verpoorte and Ericson, respectively. Furthermore, salivary pH was measured with pH paper and salivary flow rate was calculated. Salivary buffering capacity and pH were significantly lower in diabetic patients than those of healthy subjects (P < 0.05). Salivary flow rate, CA activity and DMFT levels did not differ between groups (P > 0.05). Four SNPs were detected; their pubmed database number are rs2274327 (C/T), rs2274328 (A/C), rs2274329 (G/C) and rs2274330. While first three of those were responsible for amino acid changes, the last one was not. The frequencies of SNPs were not significant between groups (P > 0.05). Positive significant correlation was found between CA activity and the frequency of SNPs. There was no correlation between the SNPs frequencies and pH or buffering capacity. SNPs found in this study may be related to salivary CA activity in diabetics.

  1. Evolution of Constitution, Structure, and Morphology in FeCo-Based Multicomponent Alloys

    NASA Astrophysics Data System (ADS)

    Li, R.; Stoica, M.; Liu, G.; Eckert, J.

    2010-07-01

    Constituent phases, melting behaviors, and microstructure of multicomponent (Fe0.5Co0.5) x (Mo0.1C0.2B0.5Si0.2)100- x alloys ( x = 95, 90, 85, 80, and 70) produced by copper mold casting were evaluated by various analysis techniques, i.e., X-ray diffractometry, scanning electronic microscopy with energy dispersive X-ray spectrometry, and differential scanning calorimetry. Metastable Fe3C- and Cr23C6-type phases were identified in the chill-cast alloys. A schematic illustration was proposed to explain the evolution of constituent phases and microstructure for the alloys with x = 95, 90, and 85 during the solidification process, which could be applicable to controlling microstructural formation of other multicomponent alloys with similar microstructures by artificially adjusting the composition.

  2. Effects of hypothermia on S100B and glial fibrillary acidic protein in asphyxia rats after cardiopulmonary resuscitation.

    PubMed

    Liu, Sha; Zhang, Yibing; Zhao, Yong; Cui, Haifeng; Cao, Chunyu; Guo, Jianyou

    2015-01-01

    The aim of the study was to investigate the effects of hypothermia on S100B and glial fibrillary acidic protein (GFAP) in serum and hippocampus CA1 area in asphyxiated rats after cardiopulmonary resuscitation (CPR). A total of 100 SD rats were designated into four groups: group A, sham operation group; group B, rats received conventional resuscitation; group C, rats received conventional resuscitation and hypothermia at cardiac arrest; group D, rats received conventional resuscitation and hypothermia at 30 min after restoration of spontaneous circulation (ROSC). Rats were then killed by cardiac arrest at 2 and 4 h after ROSC; brain tissue was taken to observe dynamic changes of S100B and GFAP in serum and hippocampus CA1 area. Following ROSC, S100B levels increased from 2 to 4 h in group B, C, and D. In addition, S100B in serum and hippocampus CA1 area was all significantly increased at different time points compared with group A (P < 0.05). Following ROSC, serum S100B level at 2 h in group C was significantly decreased compared with group B, but the difference was not statistically significant (P > 0.05). Moreover, S100B in serum at 4 h after ROSC was significantly decreased (P < 0.05), S100B in cortex was significantly decreased (P < 0.05). The expression of GFAP was also examined. GFAP level in hippocampus CA1 area was significantly decreased in group B, C, and D at 4 h after ROSC compared with group A (P < 0.05). S100B and GFAP were expressed in rat serum and hippocampus CA2 area at early stage after ROSC, which can be used as sensitive markers for brain injury diagnosis and prognosis prediction. Hypothermia is also shown to reduce brain injury after CPR.

  3. 48 CFR 32.405 - Applying Pub. L. 85-804 to advance payments under sealed bid contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... advance payments under sealed bid contracts. 32.405 Section 32.405 Federal Acquisition Regulations System... Non-Commercial Items 32.405 Applying Pub. L. 85-804 to advance payments under sealed bid contracts. (a... provisions of law relating to contracts, as explained in 50.101-1(a), also include making advance payments...

  4. Modulation of Candida albicans virulence by bacterial biofilms on titanium surfaces.

    PubMed

    Cavalcanti, Yuri Wanderley; Wilson, Melanie; Lewis, Michael; Del-Bel-Cury, Altair Antoninha; da Silva, Wander José; Williams, David W

    2016-01-01

    Whilst Candida albicans occurs in peri-implant biofilms, its role in peri-implantitis remains unclear. This study therefore examined the virulence of C. albicans in mixed-species biofilms on titanium surfaces. Biofilms of C. albicans (Ca), C. albicans with streptococci (Streptococcus sanguinis, S. mutans) (Ca-Ss-Sm) and those incorporating Porphyromonas gingivalis (Ca-Pg and Ca-Ss-Sm-Pg) were developed. Expression of C. albicans genes associated with adhesion (ALS1, ALS3, HWP1) and hydrolytic enzymes (SAP2, SAP4, SAP6, PLD1) was measured and hyphal production by C. albicans quantified. Compared with Ca biofilms, significant (p<0.05) up-regulation of ALS3, HWP1, SAP2 and SAP6, and hyphal production occurred in biofilms containing streptococci (Ca-Ss-Sm). In Ca-Pg biofilms, down-regulation of HWP1 and SAP4 expression, with reduced hyphal production occurred. Ca-Ss-Sm-Pg biofilms had increased hyphal proportions and up-regulation of ALS3, SAP2 and SAP6. In conclusion, C. albicans expressed virulence factors in biofilms that could contribute to peri-implantitis, but this was dependent on associated bacterial species.

  5. 48 CFR 970.3102-05-18 - Independent research and development and bid and proposal costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... development and bid and proposal costs. 970.3102-05-18 Section 970.3102-05-18 Federal Acquisition Regulations... Contract Cost Principles and Procedures 970.3102-05-18 Independent research and development and bid and proposal costs. (c) Independent Research and Development and Bid and Proposal costs are unallowable...

  6. Intonation development from five to thirteen.

    PubMed

    Wells, Bill; Peppé, Sue; Goulandris, Nata

    2004-11-01

    Research undertaken to date suggests that important developments in the understanding and use of intonation may take place after the age of 5;0. The present study aims to provide a more comprehensive account of these developments. A specially designed battery of prosodic tasks was administered to four groups of thirty children, from London (U.K.), with mean ages of 5;6, 8;7, 10;10 and 13;9. The tasks tap comprehension and production of functional aspects of intonation, in four communicative areas: CHUNKING (i.e. prosodic phrasing), AFFECT, INTERACTION and FOCUS. Results indicate that there is considerable variability among children within each age band on most tasks. The ability to produce intonation functionally is largely established in five-year-olds, though some specific functional contrasts are not mastered until C.A. 8;7. Aspects of intonation comprehension continue to develop up to C.A. 10;10, correlating with measures of expressive and receptive language development.

  7. Heat-induced changes to lipid molecular structure in Vimy flaxseed: Spectral intensity and molecular clustering

    NASA Astrophysics Data System (ADS)

    Yu, Peiqiang; Damiran, Daalkhaijav

    2011-06-01

    Autoclaving was used to manipulate nutrient utilization and availability. The objectives of this study were to characterize any changes of the functional groups mainly associated with lipid structure in flaxseed ( Linum usitatissimum, cv. Vimy), that occurred on a molecular level during the treatment process using infrared Fourier transform molecular spectroscopy. The parameters included lipid CH 3 asymmetric (ca. 2959 cm -1), CH 2 asymmetric (ca. 2928 cm -1), CH 3 symmetric (ca. 2871 cm -1) and CH 2 symmetric (ca. 2954 cm -1) functional groups, lipid carbonyl C dbnd O ester group (ca. 1745 cm -1), lipid unsaturation group (CH attached to C dbnd C) (ca. 3010 cm -1) as well as their ratios. Hierarchical cluster analysis (CLA) and principal components analysis (PCA) were conducted to identify molecular spectral differences. Flaxseed samples were kept raw for the control or autoclaved in batches at 120 °C for 20, 40 or 60 min for treatments 1, 2 and 3, respectively. Molecular spectral analysis of lipid functional group ratios showed a significant decrease ( P < 0.05) in the CH 2 asymmetric to CH 3 asymmetric stretching band peak intensity ratios for the flaxseed. There were linear and quadratic effects ( P < 0.05) of the treatment time from 0, 20, 40 and 60 min on the ratios of the CH 2 asymmetric to CH 3 asymmetric stretching vibration intensity. Autoclaving had no significant effect ( P > 0.05) on lipid carbonyl C dbnd O ester group and lipid unsaturation group (CH attached to C dbnd C) (with average spectral peak area intensities of 138.3 and 68.8 IR intensity units, respectively). Multivariate molecular spectral analyses, CLA and PCA, were unable to make distinctions between the different treatment original spectra at the CH 3 and CH 2 asymmetric and symmetric region (ca. 2988-2790 cm -1). The results indicated that autoclaving had an impact to the mid-infrared molecular spectrum of flaxseed to identify heat-induced changes in lipid conformation. A future study is needed to quantify the relationship between lipid molecular structure changes and functionality/availability.

  8. Baicalin prevents Candida albicans infections via increasing its apoptosis rate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Shulong; Fu, Yingyuan, E-mail: yingyuanfu@126.com; Wu, Xiuzhen

    2014-08-15

    Highlights: • Baicalin increases the ratio of the G0/G1 stages and C. albicans apoptosis. • Baicalin decreases the proliferation index of C. albicans. • Baicalin inhibits the biosynthesis of DNA, RNA and protein in C. albicans. • Baicalin depresses Succinate Dehydrogenase and Ca{sup 2+}–Mg{sup 2+} ATPase in C. albicans. • Baicalin increases the endocytic free Ca{sup 2+} concentration in C. albicans. - Abstract: Background: These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and principal findings: We detected the baicalin inhibition effects on three isotope-labeled precursors of {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucinemore » incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca{sup 2+}–Mg{sup 2+} ATPase, cytosolic Ca{sup 2+} concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca{sup 2+} concentrations of C. albicans in baicalin groups were much higher than those in control group (P < 0.05). The ratio of C.albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P < 0.01). There were a significant differences in the apoptosis rate of C.albicans between baicalin and control groups (P < 0.01). After 12–48 h incubation with baicalin (1 mg/ml), C. albicans shown to be markedly damaged under transmission electron micrographs. Innovation and significance: Baicalin can increase the apoptosis rate of C. albicans. These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase, increasing cytosolic Ca{sup 2+} content and damaging the ultrastructure of C. albicans.« less

  9. Setting Hurricane Conditions of Readiness with High Confidence.

    DTIC Science & Technology

    1984-05-01

    AD-A144 785SETTING HURRICANE CONDITIONS OF READINESS WITH HIGH i/ CONFIDENCE(U) SCIENCE APPLICATIONS INC MONTEREY CA G KOSTYSHACK ET AL. MAY 84 NEPRF...HIGH CONFIDENCE CA qtJ V m r"Prepared By: Geoff Kostyshack and Jerry Jarrell -- Science Applications, Inc. Monterey, California 93940 Contract No...N00228-83-C-3079 DTIC ELECTE AUG2 3 lg4 MAY 1984 SS APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED Prepared For: INAVAL ENVIRONMENTAL PREDICTION

  10. Definition of ground test for verification of large space structure control

    NASA Technical Reports Server (NTRS)

    Glaese, John R.

    1994-01-01

    Under this contract, the Large Space Structure Ground Test Verification (LSSGTV) Facility at the George C. Marshall Space Flight Center (MSFC) was developed. Planning in coordination with NASA was finalized and implemented. The contract was modified and extended with several increments of funding to procure additional hardware and to continue support for the LSSGTV facility. Additional tasks were defined for the performance of studies in the dynamics, control and simulation of tethered satellites. When the LSSGTV facility development task was completed, support and enhancement activities were funded through a new competitive contract won by LCD. All work related to LSSGTV performed under NAS8-35835 has been completed and documented. No further discussion of these activities will appear in this report. This report summarizes the tether dynamics and control studies performed.

  11. 41 CFR 102-74.85 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false [Reserved] 102-74.85 Section 102-74.85 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Concession...

  12. 41 CFR 102-83.85 - What is a central business area?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is a central business area? 102-83.85 Section 102-83.85 Public Contracts and Property Management Federal Property... Location of Space Urban Areas § 102-83.85 What is a central business area? Central business area (CBA...

  13. Mice lacking hippocampal left-right asymmetry show non-spatial learning deficits.

    PubMed

    Shimbo, Akihiro; Kosaki, Yutaka; Ito, Isao; Watanabe, Shigeru

    2018-01-15

    Left-right asymmetry is known to exist at several anatomical levels in the brain and recent studies have provided further evidence to show that it also exists at a molecular level in the hippocampal CA3-CA1 circuit. The distribution of N-methyl-d-aspartate (NMDA) receptor NR2B subunits in the apical and basal synapses of CA1 pyramidal neurons is asymmetrical if the input arrives from the left or right CA3 pyramidal neurons. In the present study, we examined the role of hippocampal asymmetry in cognitive function using β2-microglobulin knock-out (β2m KO) mice, which lack hippocampal asymmetry. We tested β2m KO mice in a series of spatial and non-spatial learning tasks and compared the performances of β2m KO and C57BL6/J wild-type (WT) mice. The β2m KO mice appeared normal in both spatial reference memory and spatial working memory tasks but they took more time than WT mice in learning the two non-spatial learning tasks (i.e., a differential reinforcement of lower rates of behavior (DRL) task and a straight runway task). The β2m KO mice also showed less precision in their response timing in the DRL task and showed weaker spontaneous recovery during extinction in the straight runway task. These results indicate that hippocampal asymmetry is important for certain characteristics of non-spatial learning. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. 363. A.C.S., Delineator March 1934 STATE OF CALIFORNIA; DEPARTMENT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    363. A.C.S., Delineator March 1934 STATE OF CALIFORNIA; DEPARTMENT OF PUBLIC WORKS; SAN FRANCISCO - OAKLAND BAY BRIDGE; CONTRACT NO. 6A; SUPERSTRUCTURE - WEST BAY CROSSING; SAN FRANCISCO ANCHORAGE; AMERICAN BRIDGE CO.; AMBRIDGE PLANT; ORDER NO. G4866; SHEET NO E3 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  15. EFFECT OF CHELATING AGENTS ON UPTAKE OF Ca$sup 45$ AND Sr$sup 85$ BY DEFATTED BONE IN VITRO

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samachson, J.; Lederer, H.

    The presence of chelating agents in buffered solutions affected the relative uptake of Ca/sup 45/ and Sr/sup 85/ by defatted bone powder. Strong chelating agents, like ethylenediaminetetraacetic acid and cyclohexanediaminetetraacetic acid, decreased the ratio of Ca/sup 45//Sr/sup 85/ uptake considerably in presence of Ca, Ca plus Sr, or Sr carrier. Citrate and adenosinetriphosphate had similar but weaker effects. No effect was shown by glucose, lactate, gluconate, bicarbonate, bicarbonate plus phosphate, glutamate, aspartate, borate, glycerophosphate, lysine or glutathione. Those compeunds which showed no effect had stability constants for Ca of less than 3. Strong chelating agents also decreased the relative amountmore » of Sr/sup 85/ removed from defatted bone powder by exchange. Results indicate that natural chelating agents may be partly responsible for the low Ca/sup 45//Sr/sup 85/ uptake ratio by bone from serum compared with uptake from synthetic inorganic solutions and emphasize the difficulty of removing be partly responsible for the low Ca/sup 45//Sr/sup 85/ uptske ratio by bone from serum compared with uptake from synthetic inorganic solutions and emphasize the difficulty of removing Sr/sup 35/ from bone with chelating agents now available. (auth)« less

  16. Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators

    DTIC Science & Technology

    2017-07-07

    AFRL-RH-FS-TR-2017-0026 Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators Thomas K. Kuyk Peter A. Smith Solangia...34Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators" (AFRL-RH-FS-TR- 2017 - 0026 SHORTER.PATRI CK.D.1023156390 Digitally...SUBTITLE Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators 5a. CONTRACT NUMBER FA8650-14-D-6519 5b. GRANT NUMBER 5c

  17. In vitro degradation of multisubstituted hydroxyapatite and fluorapatite in the physiological condition

    NASA Astrophysics Data System (ADS)

    Sumathi, Shanmugam; Gopal, Buvaneswari

    2015-07-01

    Structure of hydroxyapatite (HAP) is more flexible towards ionic substitutions. Properties such as solubility, antimicrobial property can be tailored by substitutions. Substituted hydroxyapatite and fluorapatite of formulae BiNaCa3(PO4)3OH, Bi0.5M0.5Ca4(PO4)3OH (M=K, Ag), Ca10-xCux(PO4)6(OH/F)2 d(x=0.05-0.25) and Bi0.5Na0.5Ca4(PO4)3F were synthesized and characterized by powder XRD, FT-IR, SEM-EDAX and TGA. In vitro solubility of the synthesized compounds was studied in the phosphate buffered medium of pH 7.4 at 37 °C. Based on the release of calcium and phosphorus ion concentration and pH, the solubility of these compounds is discussed. Bismuth and sodium co-substituted hydroxyapatite are found to be more soluble compared with other substituted apatite compounds and unsubstituted hydroxyapatite.

  18. The influence of lower leg configurations on muscle force variability.

    PubMed

    Ofori, Edward; Shim, Jaeho; Sosnoff, Jacob J

    2018-04-11

    The maintenance of steady contractions is required in many daily tasks. However, there is little understanding of how various lower limb configurations influence the ability to maintain force. The purpose of the current investigation was to examine the influence of joint angle on various lower-limb constant force contractions. Nineteen adults performed knee extension, knee flexion, and ankle plantarflexion isometric force contractions to 11 target forces, ranging from 2 to 95% maximal voluntary contraction (MVC) at 2 angles. Force variability was quantified with mean force, standard deviation, and the coefficient of variation of force output. Non-linearities in force output were quantified with approximate entropy. Curve fitting analyses were performed on each set of data from each individual across contractions to further examine whether joint angle interacts with global functions of lower-limb force variability. Joint angle had significant effects on the model parameters used to describe the force-variability function for each muscle contraction (p < 0.05). Regularities in force output were more explained by force level in smaller angle conditions relative to the larger angle conditions (p < 0.05). The findings support the notion that limb configuration influences the magnitude and regularities in force production. Biomechanical factors, such as joint angle, along with neurophysiological factors should be considered together in the discussion of the dynamics of constant force production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Structure and dielectric properties of Na0.5Bi0.5TiO3-CaTiO3 solid solutions

    NASA Astrophysics Data System (ADS)

    Birks, E.; Dunce, M.; Ignatans, R.; Kuzmin, A.; Plaude, A.; Antonova, M.; Kundzins, K.; Sternberg, A.

    2016-02-01

    Despite wide studies of Na0.5Bi0.5TiO3, structure of this material and its connection with the observed physical properties still raise numerous questions due to mutually contradicting results obtained. Here, structure and dielectric properties of poled and unpoled Na0.5Bi0.5TiO3-CaTiO3 solid solutions are studied, projecting the obtained concentration dependence of structure and dielectric properties on pure Na0.5Bi0.5TiO3 as the end member of this material group. X-ray diffraction patterns for Na0.5Bi0.5TiO3-CaTiO3 solid solutions reveal dominating of an orthorhombic Pnma phase, even for the compositions approaching the end composition (Na0.5Bi0.5TiO3), whereas structure of pure Na0.5Bi0.5TiO3 can be considered, assuming coexistence of rhombohedral and orthorhombic phases. This allows one to avoid appearance of a large difference of rhombohedral distortions between the unpoled and poled Na0.5Bi0.5TiO3, if the rhombohedral distortion is calculated as for single R3c phase. Features of dielectric permittivity, corresponding to the observed structural phase transition, are identified. It is discussed that the rhombohedral R3c phase is responsible for appearance of the frequency-dependent shoulder of dielectric permittivity temperature dependence, characteristic for unpoled Na0.5Bi0.5TiO3.

  20. Chronic clenbuterol treatment compromises force production without directly altering skeletal muscle contractile machinery

    PubMed Central

    Py, G; Ramonatxo, C; Sirvent, P; Sanchez, A M J; Philippe, A G; Douillard, A; Galbès, O; Lionne, C; Bonnieu, A; Chopard, A; Cazorla, O; Lacampagne, A; Candau, R B

    2015-01-01

    Clenbuterol is a β2-adrenergic receptor agonist known to induce skeletal muscle hypertrophy and a slow-to-fast phenotypic shift. The aim of the present study was to test the effects of chronic clenbuterol treatment on contractile efficiency and explore the underlying mechanisms, i.e. the muscle contractile machinery and calcium-handling ability. Forty-three 6-week-old male Wistar rats were randomly allocated to one of six groups that were treated with either subcutaneous equimolar doses of clenbuterol (4 mg kg−1 day−1) or saline solution for 9, 14 or 21 days. In addition to the muscle hypertrophy, although an 89% increase in absolute maximal tetanic force (Po) was noted, specific maximal tetanic force (sPo) was unchanged or even depressed in the slow twitch muscle of the clenbuterol-treated rats (P < 0.05). The fit of muscle contraction and relaxation force kinetics indicated that clenbuterol treatment significantly reduced the rate constant of force development and the slow and fast rate constants of relaxation in extensor digitorum longus muscle (P < 0.05), and only the fast rate constant of relaxation in soleus muscle (P < 0.05). Myofibrillar ATPase activity increased in both relaxed and activated conditions in soleus (P < 0.001), suggesting that the depressed specific tension was not due to the myosin head alteration itself. Moreover, action potential-elicited Ca2+ transients in flexor digitorum brevis fibres (fast twitch fibres) from clenbuterol-treated animals demonstrated decreased amplitude after 14 days (−19%, P < 0.01) and 21 days (−25%, P < 0.01). In conclusion, we showed that chronic clenbuterol treatment reduces contractile efficiency, with altered contraction and relaxation kinetics, but without directly altering the contractile machinery. Lower Ca2+ release during contraction could partially explain these deleterious effects. PMID:25656230

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