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Biomedical subjects

I G Akoev

Publications and source records attributed to I G Akoev.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Changes in serum alkaline phosphatase activity during in vitro exposure to amplitude-modulated electromagnetic field of ultrahigh frequency (2375 MHz) in guinea pigs].

The activity of alkaline phosphatase by the action of pulse-modulated microwave radiation was studied. The carrier frequency of radiation was 2375 MHz, the range of modulation pulse rate was 10-390 Hz with the on-off time ratio 2, and the specific absorption rate was 8 and 0.8 microW/cm2. Time of exposure was 1 and 3 min under conditions of continuous temperature control. It was shown that the activity of alkaline phosphatase depends on both modulation frequency and intensity of superhigh-frequency electromagnetic radiation. At a frequency of 70 Hz, the activity of alkaline phosphatases increased 1.8-2.0 times.

Alkaline Phosphatase↗
PubMedDate not supplied

[The effect of electromagnetic radiation on the monoamine oxidase A activity in the rat brain].

The effect of the ultralow power pulse-modulated electromagnetic radiation (EMR, power density 10 microW/cm2; carrying frequency 915 MHz; modulating pulses with frequency 2, 4, 6, 8, 12, 16 and 20 Hz) on activity of monoamine oxidase (MAO-A), enzyme involved in the oxidative deamination of monoamines, was investigated. It was established that the increase of activity MAO in hypothalamus reached the maximal meaning at modulation frequency of 6 Hz that corresponded 160% (p < 0.01) of the control level; and at modulation frequency of 20 Hz the decrease of enzyme activity up to 74% (p < 0.01) was found. Mainly the action of ultralow power pulse-modulated EMR on activity of MAO in hippocamp was activating; and the maximal increase of enzyme activity up to 174% (p < 0.01) was registered at modulation frequency of 4 Hz.

Animals↗
PubMedDate not supplied

[The rhythmic structure of the human EEG: the current state and trends of the research].

During the past decade, spectral analysis has become indispensable instrument for different kinds of EEG processing. With the development of dedicated computer system, investigation of shifts in human EEG rhythm under various conditions has improved considerably. However, it is difficult to make general conclusions from this line of research, since a large number of studies are carried out using the ambiguous experimental approaches and different methods. Present paper aims to evaluate a modern state of the art in the field of human EEG rhythmical structure investigation. The results from recent relevant articles are briefly reviewed according to the universal scheme (EEG rhythm--experimental condition--observed effect). Due to such presentation, the obtained results have been summarized and some tendencies of modern investigations have been revealed. The extension of studied frequency range of rhythmical EEG components to both high (> 35 Hz) and low (< 1 Hz) frequencies, the shift to a more detailed spectral structure analysis simultaneously with ignoring the fixed boundaries of traditional EEG rhythms, the growing attempts to reveal EEG rhythmical structure correlates of cognitive activity, and a wide utilization of dynamic approaches for the analysis of brain electrical activity are discussed in some detail. The observed data are indicate of high functional significance and perspectives of human EEG rhythmical structure investigation.

Brain↗
PubMedDate not supplied

[Influence of electromagnetic fields on the emotional behaviour of rats].

The effects of ultra low power pulse-width + modulation electromagnetic radiation (EMR, power density 10 mc/Wt/cm2, carrying frequency 915 MHz, modulating pulses with frequency 4, 6, 16 and 20 Hz, duration 10 min) on the rat emotional behavior and motor activity in the elevated plus-maze were studied. It was established that EMR (frequency of modulation 4 and 6 Hz) significantly decreased the emotionally negative reactions of anxiety and fear by a factor of 3.7 (p < 0.01) and 4.5 (p < 0.01) correspondingly and increased by a factor of 1.9-2.2 (p < 0.05) exploratory activity. On the contrary EMR (frequency of modulation 20 Hz) significantly increased by a factor of (p < 0.05) emotionally negative reactions of anxiety and fear and decreased by a factor of 1.8 (p < 0.05) the exploratory activity in rats.

Animals↗
PubMedDate not supplied

[Resonance phenomena to rhythmic light stimulation with various intensity and frequency in human EEG].

The photoinduced resonance EEG response in the occipital area (O1 and O2) of right-handed men during 12-s intermittent photic stimulation was studied as a function of flash frequency (6, 10, or 16 Hz) and intensity (5 levels from 0.05 to 0.7 J). The EEG power in the narrow band coinciding with stimulation frequency was FFT-extracted in 3-s intervals before, during, and after each stimulation. It was found that increase in flash intensity was accompanied by an enhancement of the resonance EEG response and decrease in time of reaching its maximal value. These changes were to a greater extent characteristic for the right hemisphere. The low-intensity stimulation induced more pronounced resonance effects in the left hemisphere, whereas the high-intensity flashes to a greater extent involved the right hemisphere. The asymmetry of the EEG response to stimulation of the middle intensity was slight, and the time of reaching the maximal level of the resonance activation was about 6-8 s. A relatively high level of the resonance EEG response was observed during stimulation with the frequency of 10 Hz, even in case of its minimal intensity. The most pronounced resonance EEG response was induced in the right occipital area by the high-intensity 16-Hz stimulation. The enhanced sensitivity of the right hemisphere to intensity of flashes is interpreted as an indication of interhemispheric differences in nonspecific adaptive mechanisms of the brain.

Brain↗
PubMedDate not supplied

[Effect of low-intensity pulse-modulated microwave on human blood aspartate aminotransferase activity].

Pulse-modulated microwaves (frequency 2375 MHz, intensity: 2 microW/cm2 and 8 microW/cm2, pulse modulation from 50 to 390 Hz with step of 20 Hz; exposure time 5 min) changed the activity of aspartataminotranspherase of the donor blood. Aspartataminotranspherase activity was strongly dependent both on modulation frequency and microwave intensity. Maximum activity was found at 390 Hz and 8 microW/cm2. Maximum observed activity was about six times greater than control level of activity.

Aspartate Aminotransferases↗
PubMedDate not supplied

[Effect of low intensity pulse-modulated electromagnetic radiation on activity of alkaline phosphatase in blood serum].

The change in alkaline phosphotase activity in vitro with frequencies modulation at low intensity of pulse-modulated electromagnetic radiation was experimentally shown (EMR, 2375 MHz, intensity: 0.8, 8.0; 40.0 microW/cm2; range modulation: 30-310 Hz; time of interaction: 1-3 min). Revealed effects could be regarded as an evidence of informative character of interaction of modulated EMR.

Alkaline Phosphatase↗
PubMedDate not supplied

[The effect of low intensity electromagnetic irradiation on hydration of DNA film].

By using the IR-spectroscopy it has been shown that electromagnetic radiation (frequency 8.15-10.0 GHz, energy flux density 5 microWt/cm2) reduces the rate of water desorption from DNA films. It was found that the irradiation of samples with high humidity did not change spectral characteristics of DNA molecules in the range of 900-4000 cm-1, that means their molecular structure remains intact. At the same time the irradiation changed conformation liability of these biopolymeric molecules, that is their ability of conformational transformations under the influence of outer factors. Drying of non-irradiated humid films induced rapid (for a few minutes) transition of DNA from B to A conformational state, whereas in the irradiated films this transition took several hours after humidity reducing.

Animals↗
PubMedDate not supplied

[Enzymatic activity of some tissues and blood serum from animals and humans exposed to microwaves and hypothesis on the possible role of free radical processes in the nonlinear effects and modification of emotional behavior of animals].

The dependence of activities of actomyosin ATPase, alkaline phosphatase, aspartataminotranspherase, monoaminoxidase and that of affective rat behavior on frequency of modulation of microwaves (0.8-10 microW/cm2) was explored at short-time actions. Series of nonlinear phenomenons, inexplicable from positions of the energy approaches are revealed, The working hypothesis explaining opportunity of high performance of weak and super-weak microwaves and other revealed phenomena by resonance interaction of such electromagnetic radiofrequency radiation with paramagnetic molecules of biological tissues was proposed. This resonance interaction activate free radicals and initiate auto-supporting and auto-intensifying of chain chemical reactions. The spontaneous autocatalytic oxidation of catecholamines enlarges a common pool of free radicals, capable to participate in such enhanced generating. The protective role of monoaminoxidase is postulated. Monoaminoxidase is basically located on an outer surface of mitochondrias and it is deaminating monoamines. The deaminating prevents penetration of catecholamines inside of mitochondrias and their quinoid oxidation there with formation of free-radical semi-quinons, capable to destroy system of ATP synthesis. These inferences are obliquely confirmed by the experimentally revealed correlation between activity of monoaminoxidase and integrative activity of the rat brain.

Alkaline Phosphatase↗