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The aim of this study was to investigate the effects of adenosine on reverse mode [Na.sup.+]/[Ca.sup.2+] exchange. In intact ferret cardiac trabeculae, [Na.sup.+]-free contractures were investigated after treating preparations with [...]

The authors describe the synthesis of amphiphilic lutetium bisphthalocyanine. The use of (super)1 H NMR and ESI mass spectrometry is analyzed.

The strikingly anisotropic large-scale distribution of matter made of an extended network of voids delimited by sheets, themselves segmented by filaments, within which matter flows towards compact nodes where they intersect, imprints its geometry on the dynamics of cosmic flows, ultimately shaping the distribution of galaxies and the redshift evolution of their properties. The (filament-type) saddle points of this cosmic web provide a local frame in which to quantify the induced physical and morphological evolution of galaxies on large scales. The properties of virtual galaxies within the horizon-AGN  simulation are stacked in such a frame. The iso-contours of the galactic number density, mass, specific star formation rate (sSFR), kinematics, and age are clearly aligned with the filament axis with steep gradients perpendicular to the filaments. A comparison to a simulation without feedback from active galactic nuclei (AGNs) illustrates its impact on quenching star formation of centrals away from the saddles. The redshift evolution of the properties of galaxies and their age distribution are consistent with the geometry of the bulk flow within that frame. They compare well with expectations from constrained Gaussian random fields and the scaling with the mass of non-linearity, modulo the redshift-dependent impact of feedback processes. Physical properties such as sSFR and kinematics seem not to depend only on mean halo mass and density: the residuals trace the geometry of the saddle, which could point to other environment-sensitive physical processes, such as spin advection, and AGN feedback at high mass. [ABSTRACT FROM AUTHOR]

The role of the cosmic web in shaping galaxy properties is investigated in the Galaxy And Mass Assembly (GAMA) spectroscopic survey in the redshift range 0.03 ≤ z ≤ 0.25. The stellar mass, u - r dust corrected colour and specific star formation rate (sSFR) of galaxies are analysed as a function of their distances to the 3Dcosmic web features, such as nodes, filaments and walls, as reconstructed by DisPerSE. Significant mass and type/colour gradients are found for the whole population, with more massive and/or passive galaxies being located closer to the filament and wall than their less massive and/or star-forming counterparts. Mass segregation persists among the star-forming population alone. The red fraction of galaxies increases when closing in on nodes, and on filaments regardless of the distance to nodes. Similarly, the starforming population reddens (or lowers its sSFR) at fixed mass when closing in on filament, implying that some quenching takes place. These trends are also found in the state-of-the-art hydrodynamical simulation HORIZON-AGN. These results suggest that on top of stellar mass and large-scale density, the traceless component of the tides from the anisotropic large-scale environment also shapes galactic properties. An extension of excursion theory accounting for filamentary tides provides a qualitative explanation in terms of anisotropic assembly bias: at a given mass, the accretion rate varies with the orientation and distance to filaments. It also explains the absence of type/colour gradients in the data on smaller, non-linear scales. [ABSTRACT FROM AUTHOR]

Polypropyleneimines (PPIs) functionalized by glycerol-based entities are prepared and characterized by diffusion-ordered spectroscopy NMR. Showing low cytotoxicity against MRC5 fibroblasts, their encapsulation capacities of gadolinium complexes was evaluated. T1 measurements were performed to determine the relaxivity of the encapsulated gadopentetate dimeglumine (GdBOPTA) in dendrimers of fourth and fifth generation (GD-PPI-4 and GD-PPI-5). Comparison of the GdBOPTA relaxivity and the relaxivity of GdBOPTA-loaded dendrimers showed a slight increase of the gadolinium chelate relaxivity. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 613-621, 2013. [ABSTRACT FROM AUTHOR]

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In this study, it was shown that adenosine potentiates caffeine-induced Ca2+ release. It was then proposed that the enhancement of the caffeine-induced Ca2+ release might occur by a direct effect on the ryanodine Ca2+ release channel or on other Ca2+ regulation mechanisms. Furthermore, A2A receptors may be functional on the ferret cardiac sarcoplasmic reticulum. Using chemically skinned fibres, experiments were conducted on ferret cardiac muscle to find out whether adenosine and the A1 and A2A adenosine receptor agonists (CCPA and CGS 21680) and antagonists (DPCPX and ZM 241385) affected caffeine-induced Ca2+ release and the Ca2+ sensitivity of contractile proteins. Changes in the caffeine-induced contracture brought about by adenosine and by adenosine-receptor agonists and antagonists were recorded in saponin-skinned fibres (50 μg ml−1). Tension–pCa relationships were then obtained by exposing Triton X-100-skinned fibres (1% v/v) sequentially to solutions of decreasing pCa. Adenosine (1–100 nm) and the specific A2A receptor agonist CGS 21680 (1–50 nm) produced a concentration-dependant potentiation of the caffeine-induced Ca2+ release from saponin-skinned fibres. The data plotted versus adenosine and CGS 21680 concentrations displayed sigmoid relationships (Hill relationship), with potentiation of Ca2+ release by , respectively. In addition, the potentiation of caffeine-induced Ca2+ release by adenosine and by CGS 21680 was reduced by the specific A2A receptor antagonist ZM 241385 (50 nm) to , respectively. The A1 receptor agonist CCPA (1–50 nm) and antagonist DPCPX (50 nm) had no significant effects on caffeine responses. In Triton X-100-skinned fibres, the maximal Ca2+-activated tension of the contractile proteins , the Hill coefficient and the pCa50 were not significantly modified by adenosine (100 nm) or by CGS 21680 (50 nm). [ABSTRACT FROM AUTHOR]

This study investigated the effect of caffeine on the sarcolemmal mechanisms involved in intracellular calcium control. Ferret cardiac preparations were treated with ryanodine and thapsigargin in order to eliminate the sarcoplasmic reticulum (SR) function. This treatment abolished caffeine contracture irreversibly in normal solution. The perfusion with K-free medium that blocked the Na+–K+ pump resulted in a recovery of slow relaxing caffeine contractures similar to Na-free contractures. The amplitude of caffeine contractures was dependent on the bathing [caffeine]o and [Ca2+]o. Divalent cations Ni2+ and Cd2+, which have an inhibitory effect on the Na+/Ca2+ exchanger, produced dose-dependent inhibition of caffeine responses with apparent Ki of 780 ± 19 and 132 ± 5 μM, respectively. Caffeine also caused dose-dependent inhibition of Na-free contractures (Ki=4.62 ± 1.5 mM), and the reduction or removal of [Na+]o exerted an inhibitory effect on caffeine contractures (Ki=73.5 ± 17.12 mM). These experiments indicate that the increase in resting tension following exposure to caffeine was mediated by Na+/Ca2+ exchanger, which represents an additional element of complexity in caffeine action on cardiac muscle. [ABSTRACT FROM AUTHOR]

Inositol 1,4,5-trisphosphate (Ins P 3), an intracellular messenger, induces Ca2+ release in various types of cells, particularly smooth muscle cells. Its role in skeletal muscle, however, is controversial. The present study shows that the application of Ins P 3 to rat slow- and fast-twitch saponin-skinned fibres induced contractile responses that were not related to an effect of Ins P 3 on the properties of the contractile proteins. The amplitude of the contractures was dependent upon the Ca2+-loading period, and was larger in slow- than in fast-twitch muscle. In both types of skeletal muscle, these responses, unlike caffeine contractures, were not inhibited by ryanodine (100 µM), but were abolished by heparin (20 µg·ml–1). In soleus muscle, the concentration of heparin required to inhibit the response by 50% (IC50) was 5.7 µg·ml–1, a similar value to that obtained previously in smooth muscle. Furthermore, the results show that in slow-twitch muscle, the Ins P 3 contractures have a "bell-shaped" dependency on the intracellular Ca2+ concentration. These results show that InsP3 receptors should be present in skeletal muscle. Thus, it is possible that InsP3 participates in the regulation of sarcoplasmic reticulum Ca2+ release in skeletal muscle, particularly in slow-twitch fibres. [ABSTRACT FROM AUTHOR]

An optically addressed spatial light modulator with electrolyte bisphtalocyanine of lutetium incorporated in the alignment layer is shown to be capable of memorizing a grey scale image. The relationship between the memorized grey scale and the illumination is shown. The temperature, the concentration of Lu(Pc)[sub 2] and the spontaneous polarization of liquid crystals are found to have the effect on the memorization rate. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]