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Physiological Solution (physiological + solution)
Selected AbstractsQuantitation of talinolol and other ,-blockers by capillary electrophoresis for in vitro drug absorption studiesELECTROPHORESIS, Issue 15 2003Bilal Awadallah Abstract A capillary zone electrophoresis method is described for the enantioseparation of talinolol using heptakis(2,3-diacetyl-6-sulfo)-,-cyclodextrin (HDAS-,-CD) as a chiral selector. After liquid-liquid extraction of talinolol from physiological solution, electrokinetic injection was employed to improve the sensitivity. The use of a coated capillary was necessary to achieve stable and reproducible enantioseparations. A baseline separation of the talinolol enantiomers was achieved in less than 10 min using 100 mM phosphate solution as background electrolyte and pH 3.5, at the presence of 3.0 mM HDAS-,-CD and at 20°C. In addition, this analytical condition proved to be useful for the enantioseparation of a number of other ,-blocking agents such as alprenolol, atenolol, bisoprolol, celiprolol, metipranolol, oxprenolol, and sotalol. For determing talinolol, the method could be validated in terms of precision, accuracy and linearity, and was found to be suitable in determination of talinolol enantiomers in highly diluted samples obtained from in vitro experiments. [source] Elaboration of Monophasic and Biphasic Calcium Phosphate Coatings on Ti6Al4V Substrate by Pulsed Electrodeposition CurrentADVANCED ENGINEERING MATERIALS, Issue 6 2010Hicham Benhayoune Calcium phosphate coatings on Ti6Al4V substrates are elaborated by pulsed electrodeposition. The surface morphology and chemical composition of the coatings are characterized by SEM,EDS. The obtained results are systematically confirmed at the nanometre scale using TEM. Moreover, XRD is performed in order to identify the coatings phases. The results show that pulsed electrodeposition allows uniform coatings to be obtained without the holes and craters usually observed with classical electrodeposition. After appropriate heat treatment, these coatings have a biphasic composition of stoichiometric hydroxyapatite and , -tricalcium phosphate. Moreover, the addition of 9% H2O2 to the electrolyte leads to monophasic coatings made of stoichiometric hydroxyapatite. As an indication of the passive nature of the electrodeposited coating, electrochemical potentiodynamic tests are performed in physiological solution in order to determine the corrosion behaviour of these coatings. [source] ,-Fe2O3 Nanorings Prepared by a Microwave-Assisted Hydrothermal Process and Their Sensing Properties,ADVANCED MATERIALS, Issue 17 2007X. Hu Free-standing , -Fe2O3nanorings are synthesized in solution through a rapid microwave-assisted hydrothermal process. The ringlike structure is a new member in the family of iron oxide nanostructures. The sensors made of the ,-Fe2O3 nanorings exhibit high sensitivity not only for bio-sensing of hydrogen peroxide in a physiological solution but also for gas-sensing of alcohol vapor at room temperature. [source] Smooth muscle contraction induced by Indigofera dendroides leaf extracts may involve calcium mobilization via potential sensitive channelsPHYTOTHERAPY RESEARCH, Issue 7 2003S. Amos Abstract The contractile effects of the aqueous extract of the leaves of Indigofera dendroides (ID) were studied on the gastrointestinal motility in mice and isolated smooth muscle preparations obtained from rats and guinea pigs. The contractile effects of 10,6 M acetylcholine, 80 mM KCl and 1.6 mg/ml ID were measured on the rat ileal smooth muscle exposed to calcium-free buffer or physiological solution, to determine the calcium pools mobilized by extract for activation of contraction. Acute toxicity test (LD50) was also carried out in mice. The result showed that ID (0.05,3.2 mg/ml) produced a concentration-dependent contraction of the guinea pig and rat ileum. These responses were not blocked by mepyramine (2.49 × 10,9 M), verapamil (8.14 × 10,9 M), or pirenzepine (4.7 × 10,7 M), but were blocked completely by atropine (2.92 × 10,9 M). A signi.cant increase in propulsion of gastrointestinal motility was observed. Acetylcholine, KCl and ID produced contractions in Ca2+ free media. The phasic components of the contractile responses to Ach as well as the tonic component of K+ and ID-induced contractions were relatively resistant to short periods of calcium-free exposure. Ach, K+ and ID still caused contractions in the presence of verapamil. The data revealed that ID-induced contractions were not mediated by histaminergic receptors, calcium channels, M1 muscarinic receptors. It also suggests that Ach mobilize Ca from some tightly bound or intracellular pool, whereas high K+ and ID may mobilize Ca from some superficial or loosely-bound pool. Copyright © 2003 John Wiley & Sons, Ltd. [source] Metabolic pathway of magnetized fluid-induced relaxation effects on heart muscleBIOELECTROMAGNETICS, Issue 8 2005Gayane Ayrapetyan Abstract The effect of magnetized physiological solution (MPS) on isolated, perfused snail heart muscle contractility, 45Ca uptake and intracellular level of cAMP, and cGMP was studied. The existence of the relaxing effect of MPS on heart muscle at room temperature (22 °C) and its absence in cold medium (4 °C) was shown. The MPS had a depressing effect on 45Ca uptake by muscles and intracellular cAMP content and an elevating effect on intracellular cGMP level. It is suggested that the relaxing effect of MPS on heart muscle is due to the decrease of intracellular Ca ions as the result of activation of cGMP-dependent Ca efflux. The MPS induced decrease of intracellular cAMP content can be considered as a consequence of intracellular Ca loss, leading to the Na,+,K-ATPase reactivation, and causing the decrease of the intracellular level of ATP, serving as a substrate and positive modulator of cyclase activity. Bioelectromagnetics © 2005 Wiley-Liss, Inc. [source] 4 Hz EMF treated physiological solution depresses Ach-induced neuromembrane currentBIOELECTROMAGNETICS, Issue 5 2004S.N. Ayrapetyan Abstract The effect of 4 Hz EMF treated physiological solution (PS) on acetylcholine (Ach) sensitivity of the snail neuron was studied. The 4 Hz EMF treated normal PS at room temperature (23 °C) has a depressing effect on Ach induced current, while in cold medium (12 °C) this effect disappeared. EMF treated, ouabain containing, K-free PS elevates the Ach-induced current at room temperature. It is suggested that the metabotropic effect of EMF treated PS is due to the activation of cGMP-dependent Na:Ca exchange, leading to the decrease of the number of functional active receptors in the membrane, through Na,K pump-induced cell shrinkage, and to increase the receptors affinity to Ach, as the result of decrease of intracellular Ca concentration. Bioelectromagnetics 25:397,399, 2004. © 2004 Wiley-Liss, Inc. [source] Numerical computation of distortions in magnetic fields and induced currents in physiological solutions produced by microscope objectivesBIOELECTROMAGNETICS, Issue 7 2001Indira Chatterjee Abstract Identifying distortions produced by commonly employed microscope objectives and their components in uniform DC and 60 Hz AC magnetic fields is important in imaging studies involving exposure of cells to spatially uniform or nonuniform magnetic fields. In this study, DC and 60 Hz AC magnetic flux densities were numerically computed in the presence of finite element models of various components of commonly utilized microscope objectives, as well as a model of a complete objective. Also computed were the distortions in the current density induced by an applied time-varying magnetic field in a physiological buffer contained within a Petri dish. We show that the magnetic flux density could be increased up to 65% in the presence of the nickel,chrome plating of an objective housing and that the presence of ferromagnetic components like a screw or spring could produce peaks that are 7% higher than the undistorted value of magnetic flux density. In addition, a slight tilt of 1% in the objective with respect to the magnetic field could cause a 93% deviation in magnetic flux density from the unperturbed value. These results correlate well with previously published experimental measurements that showed the presence of significant and sometimes asymmetric distortions in both DC and 60 Hz magnetic fields. Moreover, this study further reports that induced current density changed up to 37% compared to values in the absence of the objective. The existence of distortions in applied magnetic fields and induced currents could affect the interpretation of results of cell function studies if it is assumed that the cells are exposed to uniform magnetic flux densities in the presence of a microscope objective. Such assumptions of uniform magnetic flux density could also account for the lack of reproducibility in several studies that examined changes in intracellular calcium by imaging techniques. Bioelectromagnetics 22:463,469, 2001. © 2001 Wiley-Liss, Inc. [source] | |||||||||||||