Marie Novakova

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As many processes are regulated by both light and plant hormones, evaluation of diurnal variations of their levels may contribute to the elucidation of the complex network of light and hormone signal transduction pathways. Diurnal variation of cytokinin, auxin, and abscisic acid levels was tested in tobacco leaves (Nicotiana tabacum L. cv. Wisconsin 38)(More)
Changes in the contents of polyamines (PAs) in tobacco leaves (Nicotiana tabacum L. cv. Wisconsin 38) grown under 16 h photoperiod were correlated with arginine and ornithine decarboxylase (EC 4.1.1.19 and EC 4.1.1.17) and diamine oxidase (EC 1.4.3.6) activities. The maximum of free and soluble conjugated forms of PAs occurred 1-2 h after the middle of the(More)
Myocardial ischemia is the most common cause of death in the developed countries. The most severe manifestation is sudden death due to electrical instability, terminating in ventricular fibrillation or heart arrest. This study is based on experiments in which electrograms and monophasic action potentials are recorded from isolated guinea pig hearts perfused(More)
Monophasic action potential (MAP) can be recorded from the heart surface by optical method based on fluorescence measurement. The motion of isolated heart during experiment caused additional noise in recorded signal. The motion artifact can be eliminated by ratiometric fluorescence emission measurements. This study is based on experiments in which optical(More)
BACKGROUND The default mode network (DMN) decreases its activity when switching from a resting state to a cognitive task condition, while activity of the network engaged in the given task increases. Visual processing is typically disturbed in Parkinson's disease dementia (PDD). OBJECTIVE Using functional MRI, we studied the DMN effective connectivity(More)
Three-dimensional electrogram was used for analysis of ischemia manifestation in isolated hearts. Three parameters based on spherical coordination system were used in this study - amplitude of electrical heart vector, its azimuth and elevation. The parameters were presented as a trend. This approach reflected ischemic changes in a manner which can be easily(More)
Although sigma ligand haloperidol is known to affect repolarization in heart, its effect on potassium currents in cardiomyocytes has not yet been studied. We analyzed the effect of 1 micromol/l haloperidol on transient outward K(+) current (I(to)) in enzymatically isolated rat right ventricular cardiomyocytes using the whole-cell patch-clamp technique at(More)
The aim of this study is to learn more about influence of the voltage sensitive dye to the tissue during optical mapping experiments on isolated animal hearts. There were recordings from all phases of the experiment examined to exclude possible negative influence of the dye to the tissue. Consecutive individual heart cycles extracted from ECG signals were(More)
The paper deals with analysis of myocardial ischemia caused by left anterior coronary artery occlusion. A system based on hidden Markov models has been designed. The vectorcardiograms recorded before and during the episode of local ischemia were preprocessed by wavelet transform to reveal short-time events during ventricular depolarization. To verify the(More)
Voltage-sensitive dyes (VSDs) are used for recording of monophasic action potentials (MAPs) by optical method in excitable tissues. Their direct effects on the tissue are not completely elucidated. Previously we studied effects of VSD di-4-ANEPPS during staining and washout in Langendorff-perfused guinea pig and rabbit isolated hearts. However, most often(More)