The neurotropic effects of low-intensity electromagnetic waves in rats with different typological characteristics of higher nervous activity

The effects of the ultralow-intensity electromagnetic fields (EMF, frequency of 4200 and 970 MHz, modulated by a quasistochastic signal in the range of 20-20,000 Hz, power density 15 microW/cm2, specific body absorption rate up to 4.5 mJ/kg) on the reactions of the central nervous system (CNS) of rats with different types of behavior were studied. Some neurochemical and behavioral mechanisms of rats' reactions were investigated. It was shown that the EMF produce pronounced changes in the state and activity of monoaminergic brain systems. These changes, on the whole, correspond to the alterations at the integrative level (predominantly, of the inhibitory character).     

Intensity-time dependence dosing criterion in the EMF exposure guidelines in Russia

Major approaches of the Russian Federation in setting of exposure guidelines to electromagnetic fields (EMF) in occupational and public environments are discussed in this paper.

EMF exposure guidelines in Russia are based on the results of hygienic, clinical, physiological, epidemiological and experimental studies and are frequency-dependent. The concept of a threshold principle of occupational and environmental factors due to hazardous exposure effects has been used to set permissible exposure levels of different EMF frequency ranges. The data of experimental studies showed hazardous threshold levels of EMF effects. The main criteria of EMF hazardous exposure evaluated in the experimental study concerned both estimation of threshold levels of chronic (long-term) and acute exposure. Also, this paper contains some recent experimental study data on correlation of long-term radiofrequency and power-frequency EMF exposure effects with regard to time duration, the so-called time-dependence approach. It enables identification of the value of permissible EMF exposure levels depending on exposure duration. This approach is used in occupational exposure guideline setting and requires the introduction of “power exposition” (PE) and “maximal permissible level” (MPL). In general, EMF exposure guidelines are established with regard to possible duration of exposure per day.     

Responses to light under varying magnetic conditions in the honeybee,Apis mellifica

Summary In the dance of honeybees the indication of direction to a food source can be influenced by magnetic and photic stimuli. We have tested the behaviour of dancing honeybees illuminated with white light under varying magnetic conditions. The bees respond to the light stimulus with a maximum deviation from the correct dancing direction when they dance parallel to the inclination of the earth's magnetic field (EMF). The response to light drops to zero with increasing deviation from this zero-point direction (see also Martin and Lindauer 1977). The time of total indifference to light varies with the magnetic conditions. In the natural EMF the reaction to light becomes zero 20.3° (i.e. 1 h) after the bees have passed the zeropoint. In the compensated EMF this effect is delayed by 10°. The bees show nearly no reaction to light when the EMF is amplified to 2 Gauss.The relative spectral sensitivity of dancing honey-bees was tested in the compensated EMF. It is 1:1.63:2.64 for green-, blue-, and UV-light, respectively.Abbreviation EMF earth's magnetic field     

Presence of Circulating Anti-Myosin Antibodies in Endomyocardial Fibrosis

Background

Endomyocardial Fibrosis (EMF) is a tropical restrictive cardiomyopathy of unknown etiology with high prevalence in Sub-Saharan Africa, for which it is unclear whether the primary target of injury is the endocardial endothelium, the subendocardial fibroblast, the coronary microcirculation or the myocyte. In an attempt to explore the possibility of endocardial lesions being a result of an immune response against the myocyte we assessed the presence and frequency of circulating anti-myocardial antibodies in EMF patients.

Methodology/Principal Findings

EMF classification, assessment of severity and staging was based on echocardiography. We used sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) of myocardial proteins followed by western blotting to screen serum samples for antiheart antibodies G and M classes. The degree of serum reactivity was correlated with the severity and activity of EMF. We studied 56 EMF patients and 10 healthy controls. IgG reactivity against myocardial proteins was stronger and more frequent in patients with EMF when compared to controls (30/56; 53.6% vs. 1/10; 10%, respectively). IgM reactivity was weak in both groups, although higher in EMF patients (11/56; 19.6%) when compared to controls (n = 0). EMF patients showed greater frequency and reactivity of IgG antibodies against myocardial proteins of molecular weights 35 kD, 42 kD and 70 kD (p values <0.01, <0.01 and <0.05 respectively).

Conclusions

The presence of antibodies against myocardial proteins was demonstrated in a subset of EMF patients. These immune markers seem to be related with activity and might provide an adjunct tool for diagnosis and classification of EMF, therefore improving its management by identifying patients who may benefit from immunosuppressive therapy. Further research is needed to clarify the role of autoimmunity in the pathogenesis of EMF.     

On the modulation effect of pulsing and static magnetic fields and mechanical vibrations on barley seed hydration

The changes of wet and dry weights of barley seed in different periods of swelling were studied in seeds treated with Extremely Low Frequency Electromagnetic Fields (ELF EMF), Static Magnetic Fields (SMF) and Mechanical Vibrations (MV) in cold (4 degrees C) and warm (20 degrees C) distilled water as well as in seeds non-treated (control). The metabolic dependent seed hydration, dry weight loss and water binding in seed were modulated by preliminary EMF, SMF and MV-induced treatment of distilled water. The specific electrical conductivity (SEC) of control and treated distilled water was measured before the seed incubation. Frequency and intensity "windows" (i.e. range of frequency or intensity) for the effect of EMF, MV and SMF (correspondingly) on seed hydration, solubility and water binding in seed were studied. These "windows" were different in various phases of seed swelling. It is suggested that water structure modification is the result of valence angle changes (SMF and EMF) and dipole molecules vibration (EMF and MV) has different effects on the process of hydration, solubility and water binding in seed. These results are important from the point of understanding the mechanisms of the biological effect of EMF, as well as from the point of agriculture.     

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.     

Extremely low‐frequency electromagnetic fields accelerates wound healing modulating MMP‐9 and inflammatory cytokines

Objectives

In our previous reports, we have demonstrated that extremely low‐frequency electromagnetic fields (ELF‐EMF) exposure enhances the proliferation of keratinocyte. The present study aimed to clarify effects of ELF‐EMF on wound healing and molecular mechanisms involved, using a scratch in vitro model.

Materials and methods

The wounded monolayer cultures of human immortalized keratinocytes (HaCaT), at different ELF‐EMF and Sham exposure times were monitored under an inverted microscope. The production and expression of IL‐1β, TNF‐α, IL‐18 and IL‐18BP were measured by enzyme‐linked immunosorbent assay and quantitative real‐time PCR. The activity and the expression of matrix metalloproteinases (MMP)‐2/9 was evaluated by zymography and Western blot analysis, respectively. Signal transduction proteins expression (Akt and ERK) was measured by Western blot.

Results

The results of wound healing in vitro assay revealed a significant reduction of cell‐free area time‐dependent in ELF‐EMF‐exposed cells compared to Sham condition. Gene expression and release of cytokines analysed were significantly increased in ELF‐EMF‐exposed cells. Our results further showed that ELF‐EMF exposure induced the activity and expressions of MMP‐9. Molecular data showed that effects of ELF‐EMF might be mediated via Akt and ERK signal pathway, as demonstrated using their specific inhibitors.

Conclusions

Our results highlight ability of ELF‐EMF to modulate inflammation mediators and keratinocyte proliferation/migration, playing an important role in wound repair. The ELF‐EMF accelerates wound healing modulating expression of the MMP‐9 via Akt/ERK pathway.

     

Effects of low frequency electromagnetic field on proliferation of human epidermal stem cells: An in vitro study

To investigate the effects of low frequency electromagnetic fields (EMF) on the proliferation of epidermal stem cells, human epidermal stem cells (hESC) were isolated, expanded ex vivo, and then exposed to a low frequency EMF. The test and control cells were placed under the same environment. The test cells were exposed for 30 min/day to a 5 mT low frequency EMF at 1, 10, and 50 Hz for 3, 5, or 7 days. The effects of low frequency EMF on cell proliferation, cell cycle, and cell‐surface antigen phenotype were investigated. Low frequency EMF significantly enhanced the proliferation of hESC in the culture medium in a frequency‐dependent manner, with the highest cell proliferation rate at 50 Hz (P < 0.05). Exposure to a low frequency EMF significantly increased the percentage of cells at the S phase of the cell cycle, coupled with a decrease in the percentage of cells in the G1 phase (P < 0.05) but the effect was not frequency dependent. The percentage of CD29⁺/CD71^? cells remained unchanged in the low frequency EMF‐exposed hESC. The results suggested that low frequency EMF influenced hESC proliferation in vitro, and this effect was related to the increased proportion of cells at the S phase. Bioelectromagnetics 34:74–80, 2013. © 2012 Wiley Periodicals, Inc.     

Electromagnetic treatment to old Alzheimer's mice reverses β-amyloid deposition, modifies cerebral blood flow, and provides selected cognitive benefit

Few studies have investigated physiologic and cognitive effects of "long-term" electromagnetic field (EMF) exposure in humans or animals. Our recent studies have provided initial insight into the long-term impact of adulthood EMF exposure (GSM, pulsed/modulated, 918 MHz, 0.25-1.05 W/kg) by showing 6+ months of daily EMF treatment protects against or reverses cognitive impairment in Alzheimer's transgenic (Tg) mice, while even having cognitive benefit to normal mice. Mechanistically, EMF-induced cognitive benefits involve suppression of brain β-amyloid (Aβ) aggregation/deposition in Tg mice and brain mitochondrial enhancement in both Tg and normal mice. The present study extends this work by showing that daily EMF treatment given to very old (21-27 month) Tg mice over a 2-month period reverses their very advanced brain Aβ aggregation/deposition. These very old Tg mice and their normal littermates together showed an increase in general memory function in the Y-maze task, although not in more complex tasks. Measurement of both body and brain temperature at intervals during the 2-month EMF treatment, as well as in a separate group of Tg mice during a 12-day treatment period, revealed no appreciable increases in brain temperature (and no/slight increases in body temperature) during EMF "ON" periods. Thus, the neuropathologic/cognitive benefits of EMF treatment occur without brain hyperthermia. Finally, regional cerebral blood flow in cerebral cortex was determined to be reduced in both Tg and normal mice after 2 months of EMF treatment, most probably through cerebrovascular constriction induced by freed/disaggregated Aβ (Tg mice) and slight body hyperthermia during "ON" periods. These results demonstrate that long-term EMF treatment can provide general cognitive benefit to very old Alzheimer's Tg mice and normal mice, as well as reversal of advanced Aβ neuropathology in Tg mice without brain heating. Results further underscore the potential for EMF treatment against AD.     

Effect of electromagnetic field on cyclic adenosine monophosphate (cAMP) in a human mu-opioid receptor cell model

ABSTRACT

During the cell communication process, endogenous and exogenous signaling affect normal as well as pathological developmental conditions. Exogenous influences such as extra-low-frequency electromagnetic field (EMF) have been shown to effect pain and inflammation by modulating G-protein receptors, down-regulating cyclooxygenase-2 activity, and affecting the calcium/calmodulin/nitric oxide pathway. Investigators have reported changes in opioid receptors and second messengers, such as cyclic adenosine monophosphate (cAMP), in opiate tolerance and dependence by showing how repeated exposure to morphine decreases adenylate cyclase activity causing cAMP to return to control levels in the tolerant state, and increase above control levels during withdrawal. Resonance responses to biological systems using exogenous EMF signals suggest that frequency response characteristics of the target can determine the EMF biological response. In our past research we found significant down regulation of inflammatory markers tumor necrosis factor alpha (TNF-α) and nuclear factor kappa B (NFκB) using 5?Hz EMF frequency. In this study cAMP was stimulated in Chinese Hamster Ovary (CHO) cells transfected with human mu-opioid receptors, then exposed to 5?Hz EMF, and outcomes were compared with morphine treatment. Results showed a 23% greater inhibition of cAMP-treating cells with EMF than with morphine. In order to test our results for frequency specific effects, we ran identical experiments using 13?Hz EMF, which produced results similar to controls. This study suggests the use of EMF as a complementary or alternative treatment to morphine that could both reduce pain and enhance patient quality of life without the side-effects of opiates.     

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.     

The Short‐Term Effect of Occupational Levels of 50 Hz Electromagnetic Field on Human Heart Rate Variability

Previous studies have indicated that there is no consensus on the effects of extremely low‐frequency electromagnetic (ELF‐EMF) exposure on the cardiovascular system. This study aimed to explore the short‐term effect of ELF‐EMF exposure on heart rate (HR) and HR variability (HRV). The sample consisted of 34 healthy males aged 18–27 years. The participants were randomly assigned to the EMF (n = 17) or the Sham group (n = 17). We employed a double‐blind repeated‐measures design consisting of three 5 min experimental periods. The chest region of each individual in the EMF group was exposed to 50 Hz, 28 μT, linear polarized, continuous EMF during the EMF exposure period. HR and HRV data were recorded continuously by using a photoplethysmography sensor. Within‐subject statistical analysis indicated a significant HR deceleration in both the EMF and Sham groups. However, the standard deviation of the NN intervals (SDNN), root mean square of successive differences (RMSSD), low‐frequency (LF), and high‐frequency (HF) powers increased only in the EMF group and remained stable in the Sham group. We also compared the same HRV indices measured during the EMF and Sham periods between the two experimental groups. The between‐subject analysis results demonstrated significantly higher SDNN, RMSSD, LF, and HF values in the EMF group than in the Sham group. The LF/HF ratio did not change significantly within and between groups. On the basis of these results, we concluded that short‐term exposure of the chest region to ELF‐EMF could potentially enhance parasympathetic predominance during the resting condition. Bioelectromagnetics. 2021;42:60–75. © 2020 Bioelectromagnetics Society.     

Plasma Cytokine Profile in Tropical Endomyocardial Fibrosis: Predominance of TNF-a,IL-4 and IL-10

Background

The participation of immune/inflammatory mechanisms in the pathogenesis of tropical endomyocardial fibrosis (EMF) has been suggested by the finding of early blood and myocardial eosinophilia. However, the inflammatory activation status of late-stage EMF patients is still unknown.

Methodology/Principal findings

We evaluated pro- and anti-inflammatory cytokine levels in plasma samples from late stage EMF patients. Cytokine levels of Tumor Necrosis Factor (TNF)-α, Interferon (IFN)-γ, Interleukin (IL)-2, IL-4, IL-6, and IL-10 were assayed in plasma samples from 27 EMF patients and compared with those of healthy control subjects. All EMF patients displayed detectable plasma levels of at least one of the cytokines tested. We found that TNF-α, IL-6, IL-4, and IL-10 were each detected in at least 74% of tested sera, and plasma levels of IL-10, IL-4, and TNF-α were significantly higher than those of controls. Plasma levels of such cytokines positively correlated with each other.

Conclusions/Significance

The mixed pro- and anti-inflammatory/Th2circulating cytokine profile in EMF is consistent with the presence of a persistent inflammatory stimulus. On the other hand, the detection of increased levels of TNF-α may be secondary to the cardiovascular involvement observed in these patients, whereas IL-4 and IL-10 may have been upregulated as a homeostatic mechanism to buffer both production and deleterious cardiovascular effects of pro-inflammatory cytokines. Further studies might establish whether these findings play a role in disease pathogenesis.     

Effects of radiation emanating from base transceiver station and mobile phone on sleep,circadian rhythm and cognition in humans – a review

The electromagnetic fields (EMF) are ubiquitous. The base transceiver station (BTS) and mobile phones (MPs) contribute to the generation of EMF around their locations and are regarded as important sources of non-ionizing radiations. The use of mobile phone has increased dramatically in recent years so also the skepticism regarding its effects. In this review, we have made an attempt to scan the key research papers those aimed at elucidating the effects of EMF starting from extreme low frequency (ELF) to radio frequency (RF) through low frequency (LF). We have selected papers that dealt with the effects of radiations emanating from the BTS and MPs on human sleep, circadian rhythm, and cognition. Mostly, we have concentrated on papers published in the last 15 years. We came across conflicting reports. The findings reported in many papers suggest that the exposure to EMF has potentiality to compromise parameters related to sleep quality; in contrast, there are several reports those have given a clean sheet to the EMF exposure. The effects of EMF on circadian rhythms also remain inconclusive. The EMF exposure while did not produce any effect on circadian rhythm of heart rate and blood chemistry, it modulated the rhythms in cortisol and melatonin characterized by a decline in their 24-h circulating levels. The effects of exposure to EMF on cognitive parameters, like performance and memory, are also equivocal. The existing contradictory findings could be attributed to inter-individual variability in tolerance, gender-, and age-dependent differences in response, latitudinal differences in efficacy, variability among employed methodologies and differences in specific absorption rate, frequency of the mobile phone usage, and interaction of EMF with other physiological and environmental factors, among others. The future research should be carried out with added focus on elucidating the modulatory effects of these factors to put an end to the existing controversies on the biological effects of low/RF EMF radiations.     

Remote effects of occupational and non-occupational exposure to electromagnetic fields of power-line frequency. Epidemiological studies

A retrospective cohort study of mortality in the personnel of power-supply plants in the European regions of Russia was carried out. The exposure of the personnel to electromagnetic fields of power-line frequency (PF) was taken into account. Statistically non-significant raise of mortality from leukemia was found, compared to low mortality rates due to all other causes including cancer of any type. Standardized mortality ratio (SMR) was equal to 2.03 (95% CI = 0.23-7.31). In the retrospective case-control study the haemoblastosis development risk under occupational PF EMF exposure was evaluated. The data of 571 "cases" and 1208 "controls" interview showed that odd ratio (OR) was 1.64 (95% CI = 0.8-3.1). In another retrospective case-control study the risk of the haemoblastosis development in children due to parents PF EMF occupational exposure was evaluated. The data of 208 "cases" and 319 "controls" interview showed that the odd ratio (OR) was 1.69 (95% CI = 0.7-3.3). A retrospective cohort study of mortality in a settlement situated near a high-voltage (500 kV) substation, which took into account PF EMF levels in residential areas, revealed low mortality rates, except leukemia mortality (SMR 1.3; 95% CI = 0.2-7.0). The obtained data do not allow excluding a possibility of PF EMF leukogenic effect.     

Spindle disturbances in human-hamster hybrid (A(L) ) cells induced by the electrical component of the mobile communication frequency range signal

The production of spindle disturbances in a human–hamster hybrid (A_L) cell line by an electromagnetic field (EMF) with field strength of 90 V/m at a frequency of 900 MHz was studied in greater detail. The experimental setup presented allows investigating whether either the electrical (E) and/or the magnetic (H) field component of EMF can be associated with the effectiveness of the spindle‐disturbing potential. Therefore, both field components of a transversal electromagnetic field (TEM) wave have been separated during exposure of the biological system. This procedure should give more insight on understanding the underlying mechanisms of non‐thermal effects of EMF. A statistical comparison of the proportions of the fractions of ana‐ and telophases with spindle disturbances, obtained for five different exposure conditions with respect to unexposed controls (sham condition), showed that only cells exposed to the H‐field component of the EMF were not different from the control. Therefore, the results of the present study indicate that an exposure of cells to EMF at E‐field strengths of 45 and 90 V/m, as well as to the separated E component of the EMF, induces significant spindle disturbances in ana‐ and telophases of the cell cycle. Bioelectromagnetics 32:291–301, 2011. © 2010 Wiley‐Liss, Inc.     

In vitro increase of the fluid-phase endocytosis induced by pulsed radiofrequency electromagnetic fields: importance of the electric field component

Nowadays, due to the wide use of mobile phones, the possible biological effects of electromagnetic fields (EMF) become a public health general concern. Despite intensive research, there are no widely accepted theories about the interactions between EMFs and living cells, and the experimental data are often controversial. We examined the effects of mobile phones EMF (envelope frequency of 217 Hz, carrier frequency of 900 MHz and pulse duration of 580 micros) or its pure, low-frequency pulsed electric field component on fluid-phase endocytosis. In both cases, with exposures exceeding 10 min, an increase of the fluid-phase endocytosis rate was observed ( approximately 1.5-fold), on three different cell types. This increase is an all-or-nothing type of response that is occurring for threshold values comprised between 1.3 and 2.6 W/kg for the delivered EMF powers and between 1.1 and 1.5 V/cm for the electric fields intensities depending upon the cell type. The electric component of these EMFs is shown to be responsible for the observed increase. Variations of frequency or pulse duration of the electric pulses are shown to be without effect. Thus, EMF, via their electrical component, can perturb one of the most fundamental physiological functions of the cells-endocytosis.     

Effects of pulsed and continuous wave 902 MHz mobile phone exposure on brain oscillatory activity during cognitive processing

The aim of the current double-blind studies was to partially replicate the studies by Krause et al. [2000ab, 2004] and to further investigate the possible effects of electromagnetic fields (EMF) emitted by mobile phones (MP) on the event-related desynchronisation/synchronisation (ERD/ERS) EEG (electroencephalogram) responses during cognitive processing. Two groups, both consisting of 36 male participants, were recruited. One group performed an auditory memory task and the other performed a visual working memory task in six exposure conditions: SHAM (no EMF), CW (continuous wave EMF) and PM (pulse modulated EMF) during both left- and right-side exposure, while the EEG was recorded. In line with our previous studies, we observed that the exposure to EMF had modest effects on brain oscillatory responses in the alpha frequency range ( approximately 8-12 Hz) and had no effects on the behavioural measures. The effects on the EEG were, however, varying, unsystematic and inconsistent with previous reports. We conclude that the effects of EMF on brain oscillatory responses may be subtle, variable and difficult to replicate for unknown reasons.     

黔中地区火灾对马尾松外生菌根真菌群落的影响

林火会对森林植被及其相关联的微生物群落产生重要影响。为揭示火灾对马尾松外生菌根真菌(ectomycorrhizal fungi,EMF)群落的影响,本研究以火灾马尾松林为研究对象,以周边立地条件相对一致、未火灾马尾松林为对照,采用形态鉴定与分子生物学技术相结合的研究方法,分析火灾对马尾松EMF群落的影响。共鉴定出马尾松EMF OTUs 69个,隶属于2门7纲15目18科23属,且担子菌门丰富度明显高于子囊菌门。火灾显著改变了马尾松EMF群落的组成和结构,其中火灾马尾松林中EMF群落的优势属主要为蜡蘑属Laccaria、红菇属Russula和棉革菌属Tomentella,未火灾马尾松林中EMF群落的优势属主要为乳菇属Lactarius、棉革菌属Tomentella和土生空团菌属Cenococcum。火灾样地马尾松的EMF群落相对于对照样地在组成与结构上存在明显差异,表现出特有OTUs高于共有OTUs。相对于未火灾马尾松林,火灾马尾松EMF群落的多样性指数和丰富度指数呈下降趋势(P>0.05)。RDA分析表明,pH和TP是影响马尾松EMF群落的重要环境因子。综上所述,火灾干扰是影响黔中地区马尾松EMF群落的重要生态因素之一。