Activity of natural killer cells of the spleen of mice exposed to low-intensity of extremely high frequency electromagnetic radiation

The dose dependence of natural killer (NK) cell activity from mouse spleen upon action of low-intensity millimeter waves in the exposure range from 5 to 96 hours was studied. It has found an increase of NK activity by 24 hours posttreatment that returned to normal level in a day after the cessation of the irradiation. Also the stimulation of isolated NK cell activity after millimeter waves treatment within 1 hour was revealed.     

Suppression of nonspecific resistance of the body under the effect of extremely high frequency electromagnetic radiation of low intensity

The dynamics of leukocyte number and functional activity of peripheral blood neutrophils under whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.15 mW/cm2, 20 min daily) was studied. It was shown that the phagocytic activity of peripheral blood neutrophils was suppressed by about 50% (p < 0.01 as compared with the sham-exposed control) in 2-3 h after the single exposure to EHF EMR. The effect persisted for 1 day after the exposure, and then the phagocytic activity of neutrophils returned to the norm within 3 days. A significant modification of the leukocyte blood profile in mice exposed to EHF EMR for 5 days was observed after the cessation of exposures: the number of leukocytes increased by 44% (p < 0.05 as compared with sham-exposed animals), mostly due to an increase in the lymphocyte content. The supposition was made that EHF EMR effects can be mediated via the metabolic systems of arachidonic acid and the stimulation of adenylate cyclase activity, with subsequent increase in the intracellular cAMP level. The results indicated that the whole-body exposure of healthy mice to low-intensity EHF EMR has a profound effect on the indices of nonspecific immunity.     

Effect of extremely high frequency electromagnetic radiation of low intensity on parameters of humoral immunity in healthy mice

The modification of indices of the humoral immune response to thymus-dependent antigen (sheep erythrocytes) after a whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation was studied. Male NMRI mice were exposed in the far-field zone of horn antenna at a frequency of 42.0 GHz and energy flux density of 0.15 mW/cm2 under different regimes: once for 20 min, for 20 min daily during 5 and 20 successive days before immunization, and for 20 min daily during 5 successive days after immunization throughout the development of the humoral immune response. The intensity of the humoral immune response was estimated on day 5 after immunization by the number of antibody-forming cells of the spleen and antibody titers. Changes in cellularity of the spleen, thymus and red bone marrow were also assessed. The indices of humoral immunity and cellularity of lymphoid organs changed insignificantly after acute exposure and series of 5 exposures before and after immunization of the animals. However, after repeated exposures for 20 days before immunization, a statistically significant reduction of thymic cellularity by 17.5% (p < 0.05) and a decrease in cellularity of the spleen by 14.5% (p < 0.05) were revealed. The results show that low-intensity extremely-high-frequency electromagnetic radiation with the frequency and energy flux density used does not influence the humoral immune response intensity in healthy mice but influences immunogenesis under multiple repeated exposures.     

Degranulation of skin mast cells caused by high frequency electromagnetic irradiation of low intensity]

It was shown by light and electron microscopy that local exposure of the projection of the MC-8 lao-gun acupuncture point in rat pad to low-intensity (0.05 mW/cm2) extremely high-frequency (42.0 GHz) electromagnetic radiation caused a degranulation of derma mast cells. It was suggested that the response of skin mast cells is an important amplifying mechanism in the chain of events leading to a systemic response of the organism to low-intensity electromagnetic radiation.     

The cytotoxic activity of human natural killer cells requires an intact secretory apparatus

We have analyzed the effect of various inhibitors of cellular secretion and motility on the cytolytic activity of human natural killer (NK) cells. As effector cells we used highly purified peripheral blood lymphocytes consisting of 75–85% large granular lymphocytes (LGL) that have previously been shown to be responsible for the NK activity in man. Treatment of the effector cells with a carboxylic ionophore monensin inhibited irreversibly the NK-cell-mediated killing. This drug is known to interrupt the vesicular traffic of Golgi-derived vesicles and thus the results strongly suggested that secretory processes are required in the cytolytic activity of human NK cells. In the monensin-treated effector cells large amounts of glycoprotein accumulated in the Golgi area within 24 hr of incubation. The lytic activity did not require intact microtubules since effector cells in which vinblastine-induced tubulin-containing paracrystals were demonstrated still mediated normal NK activity. Energy was required in the human NK-cell-mediated cytolysis. The lethal hit stage of the cytolytic activity was preceded by formation of intimate contacts between effector and target cells and required active cell movement and divalent cations.     

The effects of electromagnetic radiation of extremely high frequency and low intensity on the growth rate of bacteria Escherichia coli and the role of medium pH

It has been shown that coherent electromagnetic irradiation (EMI) of extremely high frequency (45-53 GHz) or millimeter waves (wavelength 5.6-6.7 mm) of low intensity (flux capacity 0.06 mW/cm2) of Escherichia coli K12, grown under anaerobic conditions during the fermentation of sugar (glucose) for 30 min or 1 h, caused a decrease in their growth rate, the maximum inhibitory effect being achieved at a frequency of 51.8 or 53 GHz. This effect depended on medium pH when the maximal action was determined at pH 7.5. In addition, separate 30-min of 1-h irradiation (frequency 51.8 or 53 GHz) of doubly distilled water or some inorganic ions contained in Tris-phosphate buffer where the cells were transferred induced oppositely directed changes in further growth of these bacteria under anaerobic conditions; irradiation of water caused a decrease in the growth rate of bacteria. A significant change in pH of water (0.5-1.5 unit) was induced by a 30-irradiation at a frequency of 49, 50.3, 51.8, or 53 GHz, when the initial pH value was 6.0 or 8.0, but not 7.5. These results indicate the changes in the properties of water and its role in the effects of EMI of extremely high frequency. The marked effect of EMI on bacteria disappeared upon repeated irradiation for 1 h at a frequency of 51.8 or 53 GHz with an interval of 2 hours. This result indicates some compensatory mechanisms in bacteria.     

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.     

Effects of extremely low frequency electromagnetic fields on health

This paper gives a brief review of the physical interaction and bio-effects of exposure to extremely low frequency (ELF) electromagnetic fields (EMF) along with guidelines on limits of exposure to 50/60 Hz electric and magnetic fields.     

Decrease in the intensity of the cellular immune response and nonspecific inflammation upon exposure to extremely high frequency electromagnetic radiation

The effect of low-intensity extremely high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.1 mW/cm2, 20 min daily) on cell-mediated immunity and nonspecific inflammatory response in mice was studied. The intensity of cell-mediated immune response in the reaction of delayed-type hypersensitivity and nonspecific inflammation was estimated by a relative increase in the thickness of foot pad after immunization of animals by sheep red blood cells or zymosan. It was shown for the first time that the radiation reduces both immune and nonspecific inflammatory responses. It was shown with the use of models of acute inflammation and full-thickness skin wounds that EHF EMR suppresses the nonspecific inflammatory response but does not influence the duration of the pathological process. We suppose that the basis of the effects revealed is the modification of functional activity of phagocytic cells under the influence of EHF EMR. The results suggest that some therapeutic effects of EHF EMR can be realized via the inhibition of inflammatory processes.     

Effects of low-intensity extremely high frequency electromagnetic radiation on chromatin structure of lymphoid cells in vivo and in vitro

Using a comet assay technique, it was shown for the first time that low-intensity extremely high-frequency electromagnetic radiation (EHF EMR) in vivo causes oppositely directed effects on spatial organization of chromatin in cells of lymphoid organs. In 3 hrs after single whole-body exposure of NMRI mice for 20 min at 42.0 GHz and 0.15 mW/cm2, an increase by 16% (p < 0.03 as compared with control) and a decrease by 16% (p < 0.001) in fluorescence intensity of nucleoids stained with ethidium bromide were found in thymocytes and splenocytes, respectively. The fluorescence intensity of stained nucleoids in peripheral blood leukocytes was not changed after the exposure. The exposure of cells of Raji hunan lymphoid line and peripheral blood leukocytes to the EHF EMR in vitro induced a decrease in fluorescence intensity by 23% (p < 0.001) and 18% (p < 0.05), respectively. These effects can be determined by changes in a number of physiological alkali-labile sites in DNA of exposed cells. We suggested that the effects of low-intensity EHF EMR on the immune system cells are realized with the participation of neuroendocrine and central nervous systems.     

Radiosensitivity of human natural killer cells: binding and cytotoxic activities of natural killer cell subsets

The sensitivity of human natural killer (NK) cell activities (both binding and killing) after exposure of peripheral blood mononuclear cells to different doses of gamma radiation was studied. A panel of monoclonal antibodies was used to identify the NK and T-lymphocyte subsets and to evaluate their radiosensitivity. Peripheral blood mononuclear cells were irradiated with low (2-6 Gy) and high (10-30 Gy) doses and NK cell binding and cytotoxic activity against K562 target cells were studied after 3 h and 48 h in culture. The primary damage to NK cell activity was identified at the postbinding level and affected mainly the lytic machinery. After 48 h culture postirradiation, an overall depression of cytotoxic activity was observed, but ionizing radiation produced either a selection of the more cytotoxic NK cell subsets, which therefore might be considered more resistant to radiation damage than the less cytotoxic NK cells, or a long-term stimulation of cytotoxic activity in surviving cells.     

The biological effect of extremely low frequency electromagnetic fields and vibrations on barley seed hydration and germination

The changes of wet and dry weights and germination of barley seed in different periods of its swelling in nontreated (control), extremely low frequency electromagnetic fields (ELF EMF) )-treated, and extremely low frequency vibrations (ELFV)-treated cold (4 degrees C) and warm (20 degrees C) distilled water (DW) were studied. The metabolic-dependent seed hydration, dry weight dissolving, germination, and water binding in seed were modulated by preliminary EMF- and ELFV-treated DW. Frequency "windows" for the effect of EMF and ELFV on seed hydration, solubility, water binding in seed, and germination were discovered. These "windows" were different for EMF and ELFV, as well as in various phases of seed swelling. It is suggested that EMF-induced water structure modification has a different biological effect on the process of seed hydration, solubility, water binding in seed, and germination compared to ELFV.     

Dependence of anti-inflammatory effects of high peak-power pulsed electromagnetic radiation of extremely high frequency on exposure parameters

A pronounced anti-inflammatory effect of high peak-power pulsed electromagnetic radiation of extremely high frequency was shown for the first time in a model of zymosan-induced footpad edema in mice. Exposure to radiation of specific parameters (35, 27 GHz, peak power 20 kW, pulse widths 400-600 ns, pulse repetition frequency 5-500 Hz) decreased the exudative edema and local hyperthermia by 20% compared to the control. The kinetics and the magnitude of the anti-inflammatory effect were comparable with those induced by sodium diclofenac at a dose of 3 mg/kg. It was found that the anti-inflammatory effect linearly increased with increasing pulse width at a fixed pulse repetition frequency and had threshold dependence on the average incident power density of the radiation at a fixed pulse width. When animals were whole-body exposed in the far-field zone of radiator, the optimal exposure duration was 20 min. Increasing the average incident power density upon local exposure of the inflamed paw accelerated both the development of the anti-inflammatory effect and the reactivation time. The results obtained will undoubtedly be of great importance in the hygienic standardization of pulsed electromagnetic radiation and in further studies of the mechanisms of its biological action.     

Effects of extremely low frequency electromagnetic fields on membrane-associated enzymes

The effects of extremely low frequency electromagnetic fields of 75 Hz were studied on different membrane-associated enzymes. Only the activities of three enzymes out of seven exposed to the field decreased approximately of about 54-61% with field amplitudes above a threshold of 73-151 microT depending on the enzyme. The same field had no effect on the activities of either integral membrane enzymes such as Ca,ATPase, Na/K,ATPase, and succinic dehydrogenase or peripheral membrane enzymes such as photoreceptor PDE. The decrease in enzymatic activity of the field-sensitive enzymes was independent of the time of permanence in the field and was completely reversible. When these enzymes were solubilized with Triton, no effect of the field was obtained on the enzymatic activity, suggesting the crucial role of the membrane in determining the conditions for enzyme inactivation. The role of the particular linkage of the field-sensitive enzymes to the membranes is also discussed.     

Effect of human recombinant interferon on cytotoxic activity of natural killer (NK) cells and monocytes

Studies have been performed on the in vitro immunologic effects of homogeneous recombinant human leukocyte interferon, IFLrA. Large granular lymphocytes, enriched for natural killer (NK) cell activity, were pretreated wtih IFLrA or natural interferon preparations and then tested for augmentation of NK activity and of antibody-dependent cell-mediated cytoxicity (ADCC). Monocytes were tested for cytolytic and cytostatic activity in 48–72 hr radioisotopic assays performed in the presence or absence of interferon. Treatment with IFLrA caused significant augmentation of NK, ADCC, and monocyte-mediated cytotoxic activities. Even 10 units of IFLrA induced augmentation of NK activity, and 100 units or more boosted monocyte-mediated activity. The effects in each of these assays were species-specific, with no detectable effects on the activity of mouse effector cells. These results indicate that homogeneous recombinant interferon has potent in vitro immunomodulating effects and thus provide a basis for carefully examining the in vivo effects of this protein on host defenses in forthcoming clinical trials with cancer patients.     

Ultraviolet radiation inhibits human natural killer activity and lymphocyte proliferation

Exposure to ultraviolet radiation (UVR) has been implicated in the predisposition to certain neoplasms and leads to viral reactivation. Natural killer (NK) activity may play a role in immunosurveillance and response to certain viral infections. We have evaluated the sensitivity to UVR of human NK activity, a nonproliferative function, and the proliferative response to the mitogen phytohemagglutinin (PHA). In vitro exposure to UVR resulted in a dose-dependent inhibition of NK activity and response to PHA. The wavelength dependence for UVR inhibition of NK activity and of the PHA response of lymphocytes were virtually superimposable at wavelengths at or above 300 nm, but NK activity was less sensitive to UVR at 260 and 280 nm. Maximal sensitivity for both functions was found at 260 nm, consistent with a nucleic acid chromophore mediating UVR inhibition of both activities. The DNA-directed drugs mitomycin C, acridine orange, and adriamycin at concentrations that inhibit proliferation are poor inhibitors of NK activity. These results suggest that UVR inhibition of NK activity as well as proliferation may be mediated by a nucleic acid chromophore. NK activity, however, is less sensitive to direct damage of DNA by alkylation, distortion, or oxidation. At 300 nm, the amount of radiation required to inhibit NK activity and proliferation is within the range penetrating to the dermis and capillaries during environmental exposure to sunlight.     

The effect of catalytic subunit of cAMP-dependent protein kinase on the activity of cytotoxic factor from natural killer cells

The catalytic subunit of cAMP-dependent protein kinase modifies proteins of NKCF. Several proteins of the treated NKCF can be labelled with 32P. Treatment of NKCF with protein kinase enhance the cytotoxicity of NKCF.     

Effect of low intensity of electromagnetic radiation in the centimeter and millimeter range on proliferative and cytotoxic activity of murine spleen lymphocytes

It was found that single total-body exposure to electromagnetic centimeter waves (8.15-18 GHz, 1 microW/cm2, 5 h) stimulated the proliferation of mouse T and B splenic lymphocytes. The same effects were observed upon in vivo treatment of rats for 5 h with millimeter waves (42.2 GHz, amplitude modulation 10 Hz, 1 microW/cm2). The whole-body irradiation with centimeter or millimeter waves did not cause any significant changes in natural activity of killer cells. The cellular responses induced by the irradiation of isolated animal cells in vitro did not coincide with those revealed after the total-body irradiation of animals. Thus, the in vitro irradiation of natural killer cells to millimeter waves for 1 h increased their cytotoxic activity whereas, after treatment to centimeter waves for the same time, the activity of killer cells did not change. On the contrary, irradiation of T and B lymphocytes with millimeter waves (42.2 GHz, amplitude modulation 10 Hz, 1 microW/cm2, 1 h) suppressed the blasttransformation of cells. The results show a higher immunostimulative potential of centimeter waves as compared to millimeter waves.     

Neural stimulation on human bone marrow‐derived mesenchymal stem cells by extremely low frequency electromagnetic fields

Adult stem cells are considered multipotent. Especially, human bone marrow‐derived mesenchymal stem cells (hBM‐MSCs) have the potential to differentiate into nerve type cells. Electromagnetic fields (EMFs) are widely distributed in the environment, and recently there have been many reports on the biological effects of EMFs. hBM‐MSCs are weak and sensitive pluripotent stem cells, therefore extremely low frequency‐electromagnetic fields (ELF‐EMFs) could be affect the changes of biological functions within the cells. In our experiments, ELF‐EMFs inhibited the growth of hBM‐MSCs in 12 days exposure. Their gene level was changed and expression of the neural stem cell marker like nestin was decreased but the neural cell markers like MAP2, NEUROD1, NF‐L, and Tau were induced. In immunofluorescence study, we confirmed the expression of each protein of neural cells. And also both oligodendrocyte and astrocyte related proteins like O4 and GFAP were expressed by ELF‐EMFs. We suggest that EMFs can induce neural differentiation in BM‐MSCs without any chemicals or differentiation factors. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012