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1.
Mikrobiologiia ; 70(2): 248-52, 2001.
Article in Russian | MEDLINE | ID: mdl-11386058

ABSTRACT

It was found that, depending on their frequency, mechanical vibrations (MVs) can either stimulate (4 Hz) or inhibit (50 Hz) the growth and the division of the lon mutant of Escherichia coli K-12. Similar effects were observed when the MV-treated nutrient medium was inoculated with untreated mutant cells. MVs enhanced the motility of mutant cells and the fragmentation of filament cells always present in the populations of lon mutants.


Subject(s)
Escherichia coli Proteins , Escherichia coli/physiology , Protease La , ATP-Dependent Proteases , Gene Expression Regulation, Bacterial , Heat-Shock Proteins/genetics , Mutation , Serine Endopeptidases/genetics , Stress, Mechanical
2.
Radiats Biol Radioecol ; 40(4): 435-8, 2000.
Article in Russian | MEDLINE | ID: mdl-11031492

ABSTRACT

The effect of mechanical vibrations (MV) electrical conductivity of water and optical density of aqueous DNA solution. Distilled water was treated with MV of several frequencies from 3 to 5000 Hz with an intensity of 90 dB for 30 minutes. Different sensitivities of water specific electrical conductivity (SEC) were determined (the value of distilled water SEC was 209 +/- 2 microS/m). The greatest decrease of SEC (by 15.7%) under the influence of MV was observed at the frequency of 4 Hz. There was no effect at frequencies higher than 100 Hz. The treatment of DNA water solutions with MV of frequencies 4 and 10 Hz decreased its optical density by 4.2 +/- 1.1 and 4.8 +/- 1.2% correspondingly in comparison with control. In cases of treatment with frequencies of 20 and 50 Hz no effect was observed. The mechanism of MV effect on water can be connected with the changes of system structural characteristics. It is confirmed by experiments with DNA solution, where the decrease of optical density (at 260 nm) under MV treatment is conditioned with the increase of the probability of hydrogen binding formation between the bases.


Subject(s)
DNA/chemistry , Sound , Water/chemistry , Chemical Phenomena , Chemistry, Physical , Electric Conductivity , Solutions , Time Factors
3.
Radiats Biol Radioecol ; 40(3): 319-22, 2000.
Article in Russian | MEDLINE | ID: mdl-10907412

ABSTRACT

It was shown that the static magnetic field (SMF) and electromagnetic field (EMF) caused inhibition of the cell division in Escherichia coli K-12 lon mutant. The low-frequency EMF 4 Hz led to the 20% survival, but EMF at 50 Hz increased the survival of cells up to 53%. After exposure to magnetic field cells lost capacity for division and grow as filaments, unable to form the colonies on the solid media.


Subject(s)
Escherichia coli/radiation effects , Magnetics , Mutation/radiation effects , Cell Division/radiation effects , Electromagnetic Fields , Escherichia coli/cytology , Escherichia coli/growth & development , Radiation Tolerance , Time Factors
4.
Biofizika ; 44(5): 923-8, 1999.
Article in Russian | MEDLINE | ID: mdl-10624537

ABSTRACT

The effect of perfusate on the contractile activity of an isolated internally perfused heart of Helix pomatia was studied. The changes in heart activity induced by the switching of the perfusate stream were more pronounced in a potassium-free solution when the Na+, K(+)-pump was inactivated. It was found that the decrease in the amplitude of contractions of snail heart by acetylcholine (5.10(-9) M) depends on the treatment of perfusate (Ringer solution) by mechanical vibrations (4, 10, 20, and 50 Hz; 90 dB). In the solution treated with 4 Hz mechanical vibrations, the inhibiting effect of acetylcholine decreased. A similar effect was observed after inactivating the Na+, K(+)-pump by ouabain (10(-4) M). Upon treating the solution by 10, 20, and 50 Hz mechanical vibrations, these changes were not observed. Based on the data, it is suggested that the water medium of the cell can serve as a target through which mechanical vibration can affect the cascade of cell metabolic processes.


Subject(s)
Heart/physiology , Myocardial Contraction/physiology , Acetylcholine/pharmacology , Animals , Heart/drug effects , Helix, Snails/physiology , In Vitro Techniques , Perfusion , Physical Stimulation , Sodium-Potassium-Exchanging ATPase/physiology
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