[Effect of the incubation medium pH on damage to macrophages plasma membranes].

In this paper we showed the pH-dependent change in the sensitivity of the membranes of murine peritoneal macrophages to UV-radiation. This relationship is discussed in terms of lipid bilayer membrane stability modification to the action of ROS and lipid peroxidation process (LPP) at different pH. Iron-ascorbate reinforced LPP also led to pH-dependent membranes damage. The increase of the cells incubation medium temperature up to 37 degrees C, which also stimulated LPP, did not change the picture of the pH-dependent damage. Decrease of the incubation medium pH did not reduce H2O2-induced cell damage. Increase of the pH intensified the cells damage.

[Instrumental radiofrequency electromagnetic radiation dosimetry: general principals and modern methodology].

The modern experimental radiofrequency electromagnetic field dosimetry approach has been considered. The main principles of specific absorbed rate measurement are analyzed for electromagnetic field biological effect assessment. The general methodology of specific absorbed rate automated dosimetry system applied to establish the compliance of radiation sources with the safety standard requirements (maximum permissible levels and base restrictions) is described.

[Damaging effect of "Poviargol" on mice peritoneal macrophage plasma membrane].

The damaging effect of "Poviargol", a substance containing silver nanoparts, was studied. It was shown that the damaging effect of "Poviargol" took place from the concentration of 2 mkg/ml and got its maximum at 10-12 microg/ml. Decrease of the incubation temperature from 30 to 4 degreesC led to amplification of the membrane-acting effect of "Poviargol"; however, inverse relation was observed in the range from 37 to 30 degreesC. The damaging effect of "Poviargol" increased when pH of the incubating medium was raised to 8.4 and also when the concentration of calcium ions in the incubation medium was raised to 8 mmol/l. The damaging effect decreased when pH of the incubation medium was reduced to 6.3, as well as in the presence of radioprotector serotonin. Our study allows us to suppose that reactive oxygen species and lipid peroxidation make a substantial contribution to the damaging effect of "Poviargol" on the macrophage plasma membrane.

[Effect of hydroxylated fullerene C60(OH)25 on macrophage plasma membrane integrity].

Our study has shown that the damaging effect of hydroxylated fullerene C60(OH)25 on mouse peritoneal macrophage plasma membranes increased when we enlarged the concentration of fullerene in the incubation media (from 0.005 to 0.5 mg/ml), the incubation temperature (from 22 degrees C to 37 degrees C) and the time of incubation (from 30 to 90 min). In conditions of the H2O2-induced membrane damage, fullerene was observed to intensify the H2O2-induced damaging effect at a concentration of 0.05 mg/ml and reduce it at a concentration of 0.5 mg/ml. In conditions of the UV-induced membrane damage, it was discovered that the damaging effect of UV increased when C60(OH)25 nanoparticles were added to the incubation media before irradiation and decreased when they were added after irradiation. Eventual participation of ROS in damaging effects of C60(OH)25 was discussed.

[Alteration of UV-sensitivity of mice peritoneal macrophage plasma membranes by calcium ions].

Effect of Ca2+ ions on UV-induced mice peritoneal macrophage plasma membrane damage has been studied. Drop of the extracellular Ca2+ concentration has been found to result in a reduced expression of this damage. On the contrary, a raised intra- and extra-cellular Ca2+ level is associated with a higher number of cells with damaged plasma membranes. These findings make it possible to suggest that this change in the plasma membrane photosensitivity might be a result of alterations in the membrane lipid matrix electrical stability owing to UV-induced lipid photo-peroxidation. This study has also shown that free radical peroxidation of membrane lipids plays a significant part in UV-induced cell damage.

[Possibilities of using MIGI-K protective activity under conditions of radionuclide contamination].

Experimental studies of the mussel hydrolyzate (MIGI-K) have shown that this preparation can enhance both general and radiation resistance of the organism. Moreover, MIGI-K promotes elimination of incorporated radionuclides from the organism. Some properties of this preparation, in particular, the absence of toxicity or harmful side effects, have made it possible to apply MIGI-K as an adaptogen, that is, a food supplement oftherapeutic and preventive action used to increase radionuclide excretion in the Chernobyl emergency clean-up workers.

[Haemopoiesis-stimulating and radiomodifying effects of a preparation from a plant Chamaenerion angustifolium].

The experiments as conducted in mice revealed radioprotective therapeutic effect of a preparation made from a plant Chamaenerion angustifolium. The preparation per oral administration in the course of 4 to 8 days post radiation at a dose range of 7.2 to 10.8 Gy promoted an increase in total amounts of blood leukocytes, marrow bone and spleen cells, and also some increase in survival rates among the animals.

[The influence of hydrogene ion concentrations on peritoneal macrophage plasma membrane's photosensitivity].

It was demonstrated on macrophages treated with UV irradiation dose 9 J/sm2 (lamda max =306 nm) that intra- or extracellular pH reducing lead to decrease the number of cells with damaged membranes in macrophage population. An intra- or extracellular pH elevation leads to increase of UV-irradiation membrane-acting effect. It was also shown that pH-dependence of UV-irradiation damage effect has been lost after preliminary osmotic swelling of cells. The cells survived after UV-irradiation in doses 8 and 10 J/sm2 (lamda max =297 nm) have an intracellular pH lower than non-irradiated cells.

[Damaging effect of digitonin on macrophage plasma membranes exposed to UV-irradiation].

It was shown that macrophage irradiation in 4.6 J/cm2 (lambda(max) = 306 nm) dose leads to small quantity of damaged cells in cell population, which doesn't change substantially during 60 min of incubation in darkness. So as detergent digitonin treatment (without irradiation) in 3 mkg/ml concentration doesn't lead to substantial cell damage. Also the result of combined influence of UV-irradiation and digitonin added after irradiation, 15 min before the damaged cells counting, has been got. It was shown that macrophage incubation for 15 minutes leads to cell damaging twice as much sum of UV (4.6 J/cm2) and digitonin (3 mkg/ml) damaging. However the level of cell damaging obtained 30 minutes later after finishing of irradiation doesn't exceed the sum of separate effects of this factors. Further increase of postradiation time leads to synergic effect again.

[Main principles of radiobiology]. / Osnovnye printsipy v radiobiologii.

During all the history of the development of radiation biology a problem of "energy paradox"--low consumption of energy of ionizing and non-ionizing radiation in realization of irradiation effect--has been in the focus. The first principle, which contributed much to quantitative concepts of radiation biology, is a hit principle. The hit principle, as is well known, is based on physical properties of ionizing radiations: their discontinuity, quantization and probabilistic distribution in space. Hits, i.e. acts of energy interaction with substance elements, do not depend on each other and are obeyed to Poisson distribution. The other well-known principle--a target principle--is based on the understanding that a living system has some peculiarities: a structure of elements as well as their functions are heterogeneous, unequal and differ in response to the same hits. Along with a unique DNA macromolecule, a critical target structure, biological membranes (BM) with their barrier-matrix, energy and regulatory functions, which make a basis of living processes, are also can be considered as a sensitive target structure. One more principle--a principle of amplification of primary radiation lesions in critical target structures is based on the radiation post-effect, a well-known phenomenon in radiation biology. The fourth principle is a principle of target damage recovery (regulations of cell homeostasis) that means a system response to irradiation involving mechanisms of protection and reparation of lesions in DNA and BM. The progress in molecular biology and radiation biophysics achieved for the last two decades provided an especially powerful impetus to the development of those principles, which are based on the analysis of the radio-biological effects developing in time. The main principles of radiation biology consider peculiarities of physical and biological action of ionizing radiation.

[Chemical protection from ionizing radiation of low intensity]. / O khimicheskoi zashchite ot ioniziruiushchei radiatsii nizkoi intensivnosti.

It was shown that natural protectors are perspective preparations under low-level ionizing irradiation. Natural protectors influence regulatory systems of exposed organisms, mobilize endogenous background of radioresistance and intensify the total non-specific resistance of organism. Natural protectors are low- or nontoxic preparations and can be used with food.

[The problem of chemical protection from the chronic action of ionizing radiation]. / Problema khimicheskoi zashchity ot khronicheskogo deistviia ioniziruiushchei radiatsii.

Natural protectors are due to modulation of regulatory systems. Mobilization of the endogenous radioresistance background and has proved to be efficient in increasing the total resistance of the organism. It was shown, that natural protectors are perspective preparations under low-intensive irradiation. Natural protectors are low- and nontoxic preparations and can be used per os. It was established an opportunity of the prolonged protective action of natural radioprotectors.

[Current problems of chemical radiation protection of organisms]. / Sovremennye problemy protivoluchevoi khimicheskoi zashchity organizmov.

The classification has been proposed for antiradiation protective agents which are divided into four groups: I. Radioprotectors; II. Adaptogens; III. Absorbents; IV. The means of Rehabilitations. Radioprotectors in turn are subdivided into myelo-, entero- and cerebroprotectors. Adaptogens act as stimulators of radioresistance. These are natural protectors which are perspective for chemical protection under low-level ionizing irradiation. Natural protectors influence regulatory systems of exposed organisms, mobilize endogenous background of radioresistance (EBR), immunity and intensivity the total non-specific resistance of organism (TNRO). Natural protectors (extracted from cells, plants, animals) are low- or nontoxic and can be used with food. Absorbents, the means of protection from internal irradiation, are subdivided into the drugs which prevents incorporation of radioiodine by thyroid gland and absorption of radionuclides (137Cs, 90Sr, 239Pu, 241Am) in the digestive tract. The main features which distinguish radioprotective drugs of different mechanisms on human organisms are presented. The main which different programs of reability on invalids-Chernobyl.

[Mechanism of radiobiological effects of low intensity nonionizing electromagnetic radiation]. / Mekhanizm radiobiologicheskikh éffektov neioniziruiushchikh élektromagnitnykh izluchenii nizkikh intensivnostei.

The results of the research of the biological effects of the non-ionizing electromagnetic radiation were studied from the position of "thermal" and "unthermal" mechanisms. The special attention was spared to analysing the information characterising the high sensitiveness of the human and animals organism to the very-low intensity electromagnetic fields.

[Effect of small doses of ionizing radiation on the level of catecholamines and corticosteroids in mouse adrenals]. / Vliianie malykh doz ioniziruiushchei radiatsii na uroven' soderzhaniiakatekholaminov i kortikosteroidov v nadpochechnikakh myshei.

Effects of 137Cs gamma-radiation (0.06-0.54 cGy, 0.06 cGy/day) on the levels of catecholamines and corticosteroids in mouse adrenals were investigated. There were observed increase of these parameters after mice irradiation during 1-2 days and their decrease after mice irradiation during 9 days.

[Damage to macrophage membranes by exposure to middle-wave ultraviolet radiation]. / Povrezhdenie membran makrofagov pri deistvii srednevolnovogo ul'trafioletovogo izlucheniia..

An influence of middle-wave ultraviolet radiation (lambda max = 306 nm) on plasma membranes of mice peritoneal macrophages was studied by microfluorimetry analysis. It was found that a percentage of cells with damaged plasma membranes in the irradiated macrophage population reliably increased with the UVB dose starting with 6 J/cm2. Irradiation of cells with 4.2 J/cm2 UVR dose which does not cause evident damage to plasma membranes led to the latent damage which was detected by treatment with detergent digitonin (4.5 micrograms/ml).

[Modification of damaging effect of ultraviolet radiation on peritoneal macrophage membranes in mice]. / Modifikatsiia povrezhdaiushchego deistviia ul'trafioletovogo izlucheniia na membrany peritoneal'nykh makrofagov myshei.

Different factors modificating damaging effect of middle-wave ultraviolet radiation (lambda max = 306 nm) on mice peritoneal macrophage plasma membranes were studied. It was shown that damaging effect of ultraviolet declined when the cells were simultaneously treated by red light (lambda max = 713 nm). This protective effect increased when a red component of light became greater and achieved almost 100% when it consisted 28.6%. It was also found that the decrease in intra- and extracellular pH led to the decrease in damaging effect of UVR. The increase of pH bring to an elevation of UVR destructive effect.

[Alteration of intracellular pH of macrophages after UV-irradiation]. / Izmenenie vnutrikletochnogo pH makrofagov posle UF-oblucheniia.

It was shown that in vitro exposuse of mice peritoneal middle-wave ultraviolet radiation (lambdamax = 306 nm) in doses which don't damage to cause plasma membrane caused dose-dependent decreasing of their intracellular pH. After exposure of cells to 0.5 J/cm2 it was detected an acidification of intracellular contents followed by an increase of intracellular pH up to control level (after 40 min of incubation) and then above it (on 45 min of incubation). An increase of irradiation dose was accompanied by more evident reduction of intracellular pH and lack of its restoration on 45 min of postradiational incubation under irradiation with a dose of 3 J/cm2.

[Mechanisms of biophysical effects of microwaves]. / Mekhanizmy biofizicheskogo deistviia mikrovoli.

According to our and other investigators theoretical and experimental dates biophysical effects of microwaves are defined by thermal and specific biological action. Specific influence are realized by more delicate and precise ways and mechanisms of absorption and molecular relaxation of microwave energy, energy-informative interaction of radio-emission with biosystem. It include three mechanisms: synchronisation of oscillatory processes (oscillators) of irradiated object in acting electromagnetic field; selective influence of microwaves on the biomembranes, on nervous and other highly-organized systems of living organism, on the complex formation processes and fermentative activity; resonance phenomena. These mechanisms connected with parameters of acting electromagnetic field and with electrical, magnetic and other properties of biological systems.

[Influence of Ca2+ ions on UV-induced damage to mice peritoneal macrophage plasma membranes]. / Vliianie ionov na UF-indutsirovannoe povrezhdenie plazmaticheskikh membran peritoneal'nykh makrofagov myshei.

It was shown that UV-irradiation caused damage to mice peritoneal macrophage plasma membranes. A decrease in extracellular Ca2+ leads to a decrease of the damaging effect. An increase in extracellular Ca2+ or adding of calcium ionophore A23187 to the medium is accompanied by an increase in a number of damaged cells. These data allow us to suppose that modification of the damaging effect of UV-irradiation by Ca2+ ions can be bound with changing of electric stability of membrane lipid matrix.