Muscarinic acetylcholine receptors in the heart have been shown to display agonist-independent spontaneous (constitutive) activity which causes changes in the opening of cardiac ion channels and in the activity of G proteins. We investigated whether an inhibition of the constitutive activity of muscarinic receptors induced by the binding of antagonist brings about a change in the synthesis of cyclic AMP in rat cardiac membranes, and whether the action of the antagonist is stereospecific. Atropine and S-(-)-hyoscyamine were indeed found to enhance the forskolin-stimulated synthesis of cyclic AMP in rat cardiac (both atrial and ventricular) membranes by up to 24%. The effect was stereospecific and the potency of R-(+)-hyoscyamine was 30 fold lower than that of the S-(-) enantiomer, confirming that the action of hyoscyamine is receptor-mediated. The effect did not depend on the presence of endogenous acetylcholine in the system used. The results strongly suggest that the adenylyl cyclase in the heart is exposed to continuous mild inhibition by constitutively active muscarinic receptors in the membranes of cardiomyocytes., J. Říčný, F. Gualtieri, S. Tuček., and Obsahuje bibliografii
A rise in baseline cytosolic free Ca2+ in canine vascular endothelial-like cells (VEC) lining the luminal surface of the polyester arterial prosthesis is described. In one, three and six month implantation experiments we employed six adult mongrel dogs, polyester arterial prostheses Arteknit Ra K, fluorescent Ca2+ indicator Fura-2 and digital imaging microscopy to study cytosolic free Ca2+ in cultured VEC. The electron microscopy scanning of the luminal surface in different regions of the graft were also performed. A rise in cytosolic free Ca2+ in the VEC lining the luminal surface of the prosthesis is probably the result of the immunologic reaction and mechanical stress which stimulate the proliferation activity of the endothelial cells. It seems that the baseline cytosolic free Ca2+ reflects the course of the endothelization process on the polyester arterial prosthesis., P. Ondruš, R. Alberty, P. Pothier, V. Echavé, J. Poisson, G. Bkaily., and Obsahuje bibliografii
A theoretical model is presented, which attempts to account for the evaluation of complex stimuli in terms of their constituent elements that are relevant to the intent of the assessment. The subjective evaluation of a compound stimulus is postulated to be a function of the number, weight and integrity of critical components, or sub-qualities, and their interactions. The model has application to the evaluation of any stimulus complex including works of “art”. For illustrative purpose, it will here be applied to the analysis of pictorial works of art., J. P. Huston., and Obsahuje bibliografii
Antiendothelial cell antibodies (AECA) have been detected by flow cytometry analysis in 23 out of 80 patients with connective tissue diseases. Ten out of 19 serum samples from patients with systemic lupus erythematosus (SLE) were positive. These antibodies were not detectable in healthy donors. We examined the capacity of serum samples to induce endothelial cell activation by modulating cell adhesion molecule expression on human umbilical vein endothelial cells. We found that sera from both AECA-positive and AECA-negative patient groups induced a significantly higher expression of E-selectin compared to healthy controls (P<0.05). There were no differences in the ICAM-1 on VCAM-1 expression. Our data suggest that increased E-selectin expression in activated endothelium in patients with various connective tissue disorders is not related to the production of AECA., M. Horváthová, E. Jahnová, Š. Nyulassy., and Obsahuje bibliografii
The diaries of the Bohemian nobleman Johann Nepomuk Chotek (1773-1824) are an important new source for the history of music in Prague. In particular, they describe 17 concerts given by the Society of Musicians between 1804 and 1822 in the Estates Theater. The programmes of seven concerts were previously unknown. Chotek not only gives accurate dates for the performances, but also names the pieces and performers, thus supplementing the information in Michaela Freemanová‘s 2003 article on this society. As a trained music connoisseur, Chotek also critiques the orchestra and singers, judges the music, and describes the reaction of the public., Rita Steblin., and České resumé na s. 61, anglický abstrakt na s. 47.
Studie Tomáše Slavického se zabývá kancionálem "Jesličky, staré a nové písničky" od českého barokního básníka a duchovního Fridricha Bridelia a zasazením jeho repertoáru do kontextu evropské tvorby duchovních písní., The songbook Jesličky (1658) has tended to be cited primarily as an example of direct contacts between Czech and German hymnography of the 17th century. Opening the door to consideration of a broader context was the presence of certain tunes in Latin-Slovak and Latin-Croatian printed material as well. An entire set of identical tunes has subsequently been confirmed in Latin, German, Czech, Slovak, Hungarian, and Croatian hymnography. The situation outlined above has thus shifted the original issue – the “new” songs printed in Jesličky are not just a new layer of the Czech Christmas repertoire with proven German sources, but also an attempt at creating Czech versions of a supranational repertoire. The search for source models is thus growing into research surveying the new repertoire of Christmas songs that was spreading its way around Central Europe near the middle of the 17th century., Tomáš Slavický., Rubrika: Studie, and České resumé na s. 415, anglický abstrakt na s. 399.
An attempt has been made to test for a reliable method of characterizing the isovolumic left ventricular pressure fall in isolated ejecting hearts by one or two time constants, tau. Alternative nonlinear regression models (three- and four-parametric exponential, logistic, and power function), based upon the common differential law dp(t)/dt = - [p(t)-Ptau]/ tau(t) are compared in isolated ejecting rat, guinea pig, and ferret hearts. Intraventricular pressure fall data are taken from an isovolumic standard interval and from a subinterval of the latter, determined data-dependently by a statistical procedure. Extending the three-parametric exponential fitting function to four-parametric models reduces regression errors by about 20-30 %. No remarkable advantage of a particular four-parametric model over the other was revealed. Enhanced relaxation, induced by isoprenaline, is more sensitively indicated by the asymptotic logistic time constant than by the usual exponential. If early and late parts of the isovolumic pressure fall are discarded by selecting a subinterval of the isovolumic phase, ? remains fairly constant in that central pressure fall region. Physiological considerations point to the logistic model as an advantageous method to cover lusitropic changes by an early and a late tau. Alternatively, identifying a central isovolumic relaxation interval facilitates the calculation of a single ("central") tau; there is no statistical justification in this case to extend the three-parametric exponential further to reduce regression errors., S. F. J. Langer,., and Obsahuje bibliografii
Nearly all epileptic seizures in patients are characterized by deranged consciousness. We started to study changes in motivated behavior (drinking in thirsty rats) as a possible analogue of compromised consciousness during and after epileptic seizures. Epileptic afterdischarges (ADs) were elicited by stimulation of the dorsal hippocampus and/or thalamus. Rats with implanted electrodes (deprived of water for 24 hours) were trained to lick water from a narrow tube. After pretraining ADs were elicited eight times in each animal and access to water was allowed during different phases of the AD. Stimulation did not affect licking if no AD was induced. If stimulation was successful, licking was stopped in nearly 70 % of stimulations and modified (biting the tube) in 30 %. Hippocampal ADs (characterized by serrated waves in the EEG and by an arrest of behavior with subsequent automatisms) completely blocked licking, signs of recovery appeared during the interval between the AD and recurrent AD and it progressed during recurrent ADs. Thalamic ADs abolished licking in 82% of cases and immediately after ADs normal licking reappeared in 49 % of these observations. Our results suggest that changes in motivated behavior might serve as an analogue of compromised human consciousness., P. Mareš, L. Chocholová., and Obsahuje bibliografii