Luděk Strašák

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This work studies biological effects of low-frequency electromagnetic fields. We have exposed three different bacterial strains-Escherichia coli, Leclercia adecarboxylata and Staphylococcus aureus to the magnetic field (t<30 min, B(m)=10 mT, f=50 Hz) in order to compare their viability (number of colony-forming units (CFU)). We have measured the dependence(More)
PURPOSE The purpose of this study was to evaluate the effect of progressively increasing concentrations of activated and nonactivated platelet-rich plasma (PRP) on proliferation of human osteoblasts in vitro. MATERIALS AND METHODS Human osteoblasts (hFOB 1.19) obtained from the American Type Culture Collection (ATCC, Manassas, VA) were used in the(More)
The effects of low-frequency magnetic fields (Bm=2.7-10 mT, f=50 Hz, time of exposure t=0-12 min, laboratory temperature) on the viability and oxidoreductive activity of gram-negative bacteria Escherichia coli were investigated. The growth of these bacteria was negatively affected by such fields. We compared two experimental systems--solenoid [Sb. Lek. 99(More)
Enzymatic activity (denitrification) of Paracoccus denitrificans was estimated electrochemically by reduction of duroquinone (DQ). Graphite electrodes covered with whole bacterial cells behind a dialysis membrane were used for measurement. P. denitrificans reduce nitrate and/or nitrite under anaerobic conditions to nitrogen gas. DQ acts as an electron(More)
Epigenetic histone (H3) modification patterns and the nuclear radial arrangement of select genetic elements were compared in human embryonic stem cells (hESCs) before and after differentiation. H3K9 acetylation, H3K9 trimethylation, and H3K79 monomethylation were reduced at the nuclear periphery of differentiated hESCs. Differentiation coincided with(More)
A 50 Hz magnetic field effect on the growth of yeasts Saccharomyces cerevisae was studied. The cylindrical coil induced magnetic fields with inductions up to 10 mT. Duration of exposure varied up to 24 min. Exposure took place at laboratory temperature (24-26 degrees C) and the air ventilator maintained the temperature at the place of the sample. We(More)
Effect of electromagnetic low frequency fields was studied on mice. We analyzed level of protein in brain of mouse. The levels of c-Jun and c-Fos in brains were measured using Western-blot techniques. Female and male laboratory mice were exposed for 4 days to magnetic field (Bm = 2 mT, f = 50 Hz). The exposure took place in cylindrical coil at laboratory(More)
Histone variants and their epigenetic modifications determine genome function, particularly transcription. However, whether regulation of gene expression can be influenced by nuclear organization or vice versa is not completely clear. Here, we analyzed the effect of epigenetic changes induced by a histone deacetylase inhibitor (HDACi) on the nuclear radial(More)
The effect of magnetic fields on the living systems is studied in vivo or in vitro in very broad spectrum of organisms, cells and tissues. The mechanism of their acting is not known until now. We studied low-frequency magnetic field effect on cytoskeleton and on the structure of chromatin in human cells. We used cell line of small lung carcinoma (A549) and(More)
Nuclear locations of the c-myc gene and its transcripts (c-myc T) have been investigated in relation to nuclear domains involved in RNA synthesis and processing. Transcription of the c-myc gene appears to be linked to the late G1- and preferentially to S-phases of the cell cycle. The c-myc gene and its transcripts were positioned non-randomly within the(More)