Mechanism of the effect of weak electromagnetic fields on the living body]

By using the model conceptions of the dielectric polarization theory, a new mechanism for the effect of electromagnetic field was proposed. The model enables one to explain the experimentally observed influence of low-frequency weak electromagnetic field on biological objects. It was shown that, at the cellular and subcellular levels, an increase in the intensity of the electric component of external electromagnetic field can occur. The magnitude of this increase is determined by the ratio of the contributions of the medium polarization and the depolarizing factor (which depends on body shape) to the total effect. As a result of this increase, a potential comparable with intrinsic biological values can be generated on neuron membranes, which must elicit nervous and physiological responses of the organism.     

Contribution to the Chemistry of Plasma-Activated Water

Plasma-activated water (PAW) was prepared by exposure to nonthermal plasma produced by a positive dc corona discharge in a transient spark regime. The activation of water was performed in atmosphere of various surrounding gases (air, nitrogen, carbon dioxide, and argon). This PAW retains its biological activity, measured on the mouse neuroblastoma cells culture, even after storage for more than one year. The highest hydrogen peroxide content was found for PAWs prepared in the atmospheres of argon or carbon dioxide, whereas the PAWs prepared in air and nitrogen exhibited lower hydrogen peroxide content. The acidity of PAWs mediated by nitric and nitrous acid formation displayed an opposite trend. It is concluded that the long-lasting biological effect of PAW is mediated by hydrogen peroxide in acid milieu only, whereas other possible active components decompose rapidly.     

Mechanisms for survival of bacteria in oxidative stress and iron ions deficiency

The influence of culture medium Fe2+ content on the resistance of Escherichia coli to hydroxyl radicals formed in the presence of Fe2+ and hydrogen peroxide in Fenton reaction was investigated. It was founded that a lack of Fe2+ in a culture medium increased resistance of bacteria to hydroxyl radicals but not to hydrogen peroxide. The suggestion was made that the lack of Fe2+ starts up synthesis of metabolites which inactivate hydroxyl radical or block Fe2+ ions participating in Fenton reaction. The phenomenon under study is considered to be a possible mechanism for survival of bacteria in oxidative stress and iron ions deficiency.     

Calcium-dependent and calcium-independent mechanisms of irreversible cell injury in cultured hepatocytes

It has been proposed that alterations in intracellular calcium homeostasis mediate the genesis of lethal cell injury with an acute oxidative stress. It is shown here, however, that such changes can be dissociated by two different means from the cell death occurring with the exposure of cultured hepatocytes to hydrogen peroxide generated either in the medium by glucose oxidase or intracellularly by the mechanism of menadione. The chelation of intracellular ferric iron with deferoxamine inhibits the formation of hydroxyl radicals from hydrogen peroxide and prevents cell killing. Deferoxamine did not prevent, however, an elevation of the cytosolic Ca2+ ion concentration detected as an activation of phosphorylase alpha. Sulfhydryl reagents inhibited the rise in phosphorylase alpha activity in deferoxamine-pretreated hepatocytes. Conversely, cultured hepatocytes were depleted of Ca2+ ions by treatment with EGTA in a calcium-free medium. Calcium-depleted cells were not resistant to the toxicity of hydrogen peroxide despite the virtual elimination of the activation of phosphorylase alpha. In contrast, it was possible to kill cultured hepatocytes by a mechanism dependent upon a disordered intracellular calcium homeostasis using hepatocytes pretreated in calcium-free medium with the ionophore A23187. These cells were killed in a dose-dependent manner by the addition of calcium ions to the culture medium in concentrations ranging from 0.1 to 2.0 mM. There was a similar dose-dependent activation of phosphorylase alpha, but phosphorylase alpha activities were higher than with H2O2 at comparable cell killing. Deferoxamine pretreatment and sulfhydryl reagents had no effect on the loss of viability with this calcium-dependent cell killing.     

Effect of a low-frequencey magnetic field on esterase activity and change in pH in wheat germ during swelling of wehat seeds

The role of nonsteady phenomena determined by a low velocity of ion movements in a weak external field is considered in relation to their possible nonlinear effects on processes occurring in boundary layers near the membrane, particularly, on the release of membrane-bound proteins and pH value. It is shown that a short-term treatment of wheat seeds with low-frequency magnetic field at the stage of esterase activation during seed swelling enhances the activation of esterases; the effect observed at final stages of activation depends on the time after the treatment with electromagnetic field. Treatment of seeds with electromagnetic field at this stage changed qualitatively the time course of the release of reaction products into the medium: the reaction rate increased initially and then decreased below the control level. At earlier stages of swelling in treated seeds and at all stages in control seeds, the time course of the product release was linear. The retardation of the release of the reaction products at terminal stages of esterase activation is presumably related to the release of proteins and their complexes under the action of electromagnetic field and the resulting restoration of the barrier properties of membranes. Treatment with electromagnetic field also caused a noticeable acceleration of proton flow form the medium, which was judged from pH changes in the bulk medium and in the vicinity of germ surface. The difference between the treated and control samples after 23-24 h of imbibition became statistically significant and was as high as 0.4 pH units. By taking into account the nonsteady phenomena occurring upon action of low-frequency electromagnetic field, it is possible to explain unusual dependences of biological effects on the amplitude of the electromagnetic field, including the atypical enhancement of these effects by the action of weak low-frequency fields.     

Physical basis of adverse and therapeutic effects of low intensity microwave radiation

A physical basis of adverse and therapeutic effects of low intensity microwave radiation is presented based on the concept of oscillatory similitude between the frequency of an external microwave field (together with any lower frequency modulations thereof) and those of certain endogenous dipolar coherent excitations allied to aliveness, which play the role of 'tuned circuits' via which a living organism is electromagnetically sensitised in a non-linear way to external fields too weak to be able to cause heating. From this perspective, an external electromagnetic field affects a living system not as a toxin but rather by perturbing its endogenous electromagnetic activity. The possibility of adverse perturbation is illustrated by reference to the microwave fields used in mobile telecommunications whose signals interfere in a non-thermal way with biofunctionality--in particular, undermining the efficacy of processes that would otherwise afford natural protection against the development of pathology. Therapeutic modalities of microwave exposure, on the other hand, are illustrated using the example of microwave resonance therapy--which can be considered as an electromagnetic version of acupuncture, and as an example of 'quantum medicine'--whose normalising effect on a wide range of pathologies is striking, and which affords a novel alternative to conventional pharmacological interventions.     

Induction of micronuclei in cultured murine splenocytes exposed to elevated levels of ferrous ions, hydrogen peroxide and ultraviolet irradiation

The frequency of micronuclei in cultured mouse splenocytes increased positively and in a dose-related manner to exposure to ferrous ions and ultraviolet irradiation, but not to hydrogen peroxide. Combined treatments, especially when ferrous ions were present with hydrogen peroxide or with ultraviolet irradiation, led to a synergistic enhancement in micronucleus frequency. The results indicate that a significant level of chromosome damage is associated with exposure to ultraviolet light and to general cellular pro-oxidative stress, and indicate that under these conditions the micronucleus assay can provide an effective in vitro model for the study of genotoxicity in relation to oxygen-derived free radicals.     

The impact of background radiation,illumination and temperature on EMF-induced changes of aqua medium properties

The effects of extremely low frequency electromagnetic field (ELF EMF) on physicochemical properties of physiological solution at different environmental media were studied. The existence of frequency “windows” at 4 and 8 Hz frequencies of ELF EMF having effects on heat fusion period, hydrogen peroxide (H₂O₂) formation and oxygen (O₂) content of water solution and different dependency on temperature, background radiation and illumination was shown. Obtained data allow us to suggest that EMF-induced effect on water physicochemical properties depends on abovementioned environmental factors. As cell bathing medium is a target for biological effects of ELF EMF, the variability of experimental data on biological effects of EMF, obtained in different laboratories, can be explained by different environmental conditions of experiments, which very often are not considered adequately.     

Ultrasound induced the formation of nitric oxide and nitrosonium ions in water and aqueous solutions

Nitric oxide, nitrosonium ions, nitrites, and nitrates are formed in water saturated with air under the action of ultrasound. Nitrosonium ions react with water and hydrogen peroxide to form nitrites and nitrates in sonicated solution, correspondingly. Nitric oxide is practically completely released from sonicated water into the atmosphere and reacts with air oxygen, forming NOx compounds. The oxidation of nitric oxide in aqueous medium by hydroxyl radicals and dissolved oxygen is a minor route of the formation of nitrites and nitrates in ultrasonic field.     

Membranotropic effects of electromagnetic radiation of extremely high frequency on Escherichia coli

It was found that "sound" electromagnetic radiations of extremely high frequencies (53.5-68 GHz) or millimeter waves (wavelength range of 4.2-5.6 mm) of low intensity (power density 0.01 mW) have a bactericidal effect on Escherichia coli bacteria. It was shown that exposure to irradiation of extremely high frequencies increases the electrokinetic potential and surface change density of bacteria and decreases of membrane potential. The total secretion of hydrogen ions was suppressed, the H+ flux from the cytoplasm to medium decreased, and the flux of N,N'-dicyclohexylcarbodiimide-sensitive potassium ions increased, which was accompanied by changes in the stoichiometry of these fluxes and an increase in the sensitivity of H+ ions to N,N'-dicyclohexylcarbodiimide. The effects depended on duration of exposure: as the time of exposure increased, the bactericidal effect increased, whereas the membranotropic effects decreased. The effects also depended on growth phase of bacteria: the irradiation affected the cells in the stationary but not in the logarithmic phase. It is assumed that the H(+)-ATPase complex F0F1 is involved in membranotropic effects of electromagnetic radiation of extremely high frequencies. Presumably, there are some compensatory mechanisms that eliminate the membranotropic effects.     

Effect of low-frequency alternating magnetic fields on the rate of biochemical reactions proceeding with formation of reactive oxygen species

It is (theoretically) shown by an example of the reaction of a radical with an oxygen molecule that the alternating component of a combined weak magnetic field affects the rate constants of chemical reactions. The mechanism of transduction of a weak magnetic perturbation from the primary receptor of the field to experimentally observed biological effects is followed. It is stated that the external magnetic field alters the initial population of energy levels. The magnitude of these changes depends on the field parameters. The exposure to an alternating field with proper parameters can substantially increase the concentration of reactive oxygen species in biological systems. By controlling their concentration by means of weak magnetic field, it is possible to affect the key links of metabolism.     

Microwave effects on immobilized peroxidase chemiluminescence

Protein gels formed by crosslinking bovine serum albumin and horseradish peroxidase with glutaraldehyde were used to measure effects on peroxidase activity of 400-MHz (CW) radiofrequency radiation (RFR) at an average specific absorption rate (SAR) of 1.45 W/kg. The enzyme activity was measured by luminol chemiluminescence recorded on photographic film after hydrogen peroxide activation. Activity was measured during RFR exposure of gels or after exposure of gels polymerized in the RFR field. During exposure, a significant (P less than .05) reversible increase occurred in overall mean peroxidase activity of gels activated with 0.88 M H2O2 but not in those activated with 8.8 M H2O2. Gels containing solubilized luminol and formed in the field showed no overall mean increase in peroxidase activity, but did display a highly significant (P less than .001) alteration in the distribution of local activities when compared to unexposed gels. These results are apparently due to changes in the rate of diffusion (concentration equilibration) of hydrogen peroxide in the gel.     

Rapid suppression of multidrug resistance of leukemic cells by oxidative srtess

The effect of a short-time (1 h) oxidative stress on multidrug resistance (MDR) of murine leukemic P388VR cells has been investigated. We studied the production of reactive oxygen species (ROS) in cells depending on the composition of medium and the concentration of cells and hydrogen peroxide, as well as the effect of hydrogen peroxide on MDR of cells. MDR was determined from the transport of calcein acetoxymethyl ester out of the cells and from a change in cell sensitivity to vincristine. The amount of ROS arising in cells was determined using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH₂-DA). It was shown that the rate of ROS formation in cells decreases after the addition of serum to the medium and with an increase of the cell number. By the action of hydrogen peroxide, the amount of ROS increases directly with its concentration. Oxidative stress generated by 30–300 μM hydrogen peroxide decreases the MDR of the cells. The effect of hydrogen peroxide increases with the treatment duration and concentration of hydrogen peroxide. MDR determined by the criterion of the efflux of calcein ester from cells is completely suppressed after 1-h exposure to 300 μM hydrogen peroxide. At a concentration of hydrogen peroxide of 60 μM and treatment duration of 1 h, the sensitivity of P388VR cells to vincristine increases to reach the sensitivity of the wild-type P388 cells. Rapid (about 1 h) suppression of MDR is caused by inhibition of the activity of transport proteins. MDR decrease induced by oxidative stress can be used in therapy of tumors resistant to anticancer drugs.     

Oxygen toxicity in Treponema pallidum: deoxyribonucleic acid single-stranded breakage induced by low doses of hydrogen peroxide

The effect of hydrogen peroxide on Treponema pallidum was investigated. The in vitro loss of virulence (as measured by rabbit inoculation) of T. pallidum was accelerated by as low as 100 microM hydrogen peroxide in the complex maintenance medium used. Higher doses led to rapidly accelerated death with 500 microM hydrogen peroxide causing sterilization of the medium within 3 to 4 h. Since hydrogen peroxide is known to cause single-stranded breaks in DNA, the effect of hydrogen peroxide on the treponemal genome was examined. Extensive breakage was caused by 100 microM hydrogen peroxide as determined on alkaline sucrose gradients. A limit was reached at 250 microM and above. Single-stranded breaks could be demonstrated as early as 5-10 min after exposure to hydrogen peroxide when the treponemes were exposed to 250 microM hydrogen peroxide; accelerated death was evident by 2 h past exposure demonstrating that DNA breakage was preceding death. Treponemal death caused by penicillin did not result in DNA breakage. The repair-proficient bacterium Escherichia coli K-12 was compared with T. pallidum. It required 10-100 times more hydrogen peroxide to cause various levels of breakage. Escherichia coli K-12 rapidly repaired DNA breakage once hydrogen peroxide was removed by addition of catalase. Treponema pallidum, in comparison, showed little or no repair in vitro. Addition of catalase or dithiothreitol to the medium protected against all but a low level of breakage; this may reflect on the ability of catalase and reducing agents to protect T. pallidum against oxygen toxicity in vitro.     

Cloning of sucrase genes from Streptococcus mutans in bacteriophage lambda

Abstract An extracellular peroxidase was purified by chromatofocusing column chromatography from the growth medium of ligninolytic cultures of the white-rot fungus Phanerochaete chrysosporium Burds BKM-1767. The enzyme was electrophoretically pure with an M _r of 45 000–47 000. It contained an easily dissociable heme, and required Mn²⁺ ions for activity. In the presence of hydrogen peroxide and Mn²⁺ it oxidized compounds such as vanillylacetone, 2,6-dimethyloxyphenol, curcumin, syringic acid, guaiacol, syringaldazine, divanillylacetone, and coniferyl alcohol. It did not oxidize veratryl alcohol. In reactions requiring Mn²⁺ and O₂, but not hydrogen peroxide, the enzyme oxidized glutathione, dithiothreitol, and NADPH with production of hydrogen peroxide. The hydrogen peroxide produced could be used as a co-substrate by ligninases such as those that oxidize veratryl alcohol, or by the peroxidase itself to oxidize lignin model compounds.     

Oxygen protection of bacteriophage T1 against ionizing radiations

Bacteriophage T1 was suspended in distilled water and in phosphate buffer, saturated with oxygen, nitrogen, hydrogen, and carbon monoxide, and irradiated with gamma rays and x-rays. Under the same conditions phage was exposed to hydrogen peroxide. Oxygen acted as a protective agent against both irradiation and hydrogen peroxide inactivation. As a protective agent against irradiation, oxygen was more efficient in distilled water than in buffer. The phage was much more sensitive to irradiation in the presence of hydrogen or nitrogen than in the presence of oxygen. Survivals of phage irradiated in suspensions saturated with hydrogen and with nitrogen did not differ significantly. From this it was concluded that oxygen did not protect T1 by removing atomic hydrogen from the irradiated medium, since the hydrogen-saturated medium increased the yield of atomic hydrogen but did not increase the yield of inactivated phage. It was presumed, therefore, that phage is sensitive to OH radicals and this was confirmed by irradiating phage with UV in the presence of hydrogen peroxide and comparing this survival with the survivals obtained from hydrogen peroxide alone and from UV alone. The combined effect of hydrogen peroxide and UV acting simultaneously was greater than the effect attributable to hydrogen peroxide and UV acting separately. Evidence for sensitivity to HO₂ radicals was considered, and the effect was attributed chiefly to an oxidizing action since phage sensitivity is greater at higher hydrogen ion concentrations, which favor oxidation by HO₂ radicals. Since the OH radical is a more efficient oxidizing agent than O^-, the former being favored in an acid medium, the latter in an alkaline medium, and since the phage is more sensitive in the first situation than in the second, the present tests proved the importance of oxidation as the mechanism of inactivation. Since some inactivation was encountered when phage was exposed to reducing agents, independently of irradiation, it was concluded that phage is somewhat sensitive to reducing agents, but the inactivation attributable to ionizing radiations is due chiefly to oxidation, against which these reducing agents are very efficient protectors. Under no circumstances did hydrogen peroxide protect T1, whether produced by irradiation in the medium or added beforehand to the medium to be irradiated. The first point was investigated by irradiating T1 in the presence of hydrogen and oxygen combined; this produced a higher yield of hydrogen peroxide but a lower survival of T1. In all these tests phage survival under irradiation was directly correlated with oxygen content of the medium rather than with production of hydrogen peroxide. It is proposed that the protective effect of oxygen is due to a reaction between the phage and oxygen, and this complex confers stability upon the phage.     

Level of hydrogen peroxide in electrochemically activated solutions and study of its effect on growth of Escherichia coli

The formation of hydrogen peroxide in catholytes and anolytes of electrochemically activated solutions: bidistilled water and solutions of sodium chloride and nutrition medium M9 was studied. The concentration of hydrogen peroxide was determined by the method of enhanced chemiluminescence in a system peroxidase-luminol-p-iodophenol. It was shown that the concentration of hydrogen peroxide depends on the ionic content of the solution and varies from a few fractions of a micromole in catholytes of bidistilled water and sodium chloride solutions (10(-5) divided by 10(-2) M) to 20-25 microM in catholytes of medium M9. The concentration of H2O2 in anolytes of various solutions was 15-20 times lower than in the corresponding catholytes and was equal to a few nanomoles in bidistilled water and a few micromoles in medium M9. The biological activity of the catholyte of medium M9 was determined from changes in the growth of E. coli cells. It was found that this catholyte stimulates the cell growth. The stimulating effect was 20-25% and did not change after the decomposition of hydrogen peroxide in the catholyte by catalase. The addition of H2O2 at the corresponding concentration to the inactivated nutrient medium produced no stimulating effect. These data suggest that hydrogen peroxide formed in the catholyte of nutrient medium M9 does not affect its biological activity.     

An alternative hypothesis for the direction of hydrogen ion movement and energy transduction in H. halobium.

It is generally accepted that purple membrane of $\text{H.}\text{halobium}$ functions as a light-driven hydrogen ion pump translocating hydrogen ions from inside the cell to the external medium. However, experimental data from this laboratory together with those obtained by others have always shown an initial alkalinization of the external medium in the light. Additionally, we have found that oxygen can also induce an alkalinization of the bathing solution in the dark. These results can be readily explained if the direction of hydrogen-ion translocation is reversed, that is that both light and oxygen generate an electrochemical gradient of hydrogen ions, which is outwardly directed for ATP synthesis.     

Primary mechanisms of the biological effect of electromagnetic fields

Based on the model of a bulk knitted structure, a possible mechanism of action of an external electromagnetic field on biological systems was proposed. The electromagnetic field affects biological processes through changes in the rates of biochemical reactions in response to changes in the conformational properties of water in the electromagnetic field.     

Operator of pair electron-ion collisions in alternating electromagnetic fields

Collisions of electrons with ions in the presence of an alternating electromagnetic field are considered. Based on the first principles (the Liouville equations for N particles), a general expression for the collisional operator in the approximation of pair collisions at an arbitrary scattering potential, including that depending periodically on time, is derived. The problem of collisions in plasma in the presence of an electromagnetic field can be reduced to this case by introducing drift coordinates. It is shown that the method of test particles can be applied to the problem of particle collisions in an alternating electromagnetic field.