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PubMed1980

[Changes in arterial elasticity after high-frequency electromagnetic field irradiation].

Results are reported and discussed of elastographic studies in human subjects, irradiated with electromagnetic field, 66 kH frequency and 40 V/m and 0.14 A/m intensities, i.e. with low intensity electric field (borderline normal values for a whole working day). Two types of response to electric field exposure were recorded, depending on the baseline state of the arteries. The changes in the functional state of the vascular system are characterized by signs of hypotonia and vascular tonus changes. The technique of indirect determination of blood vessel elasticity shows a high sensitivity in these weak electromagnetic fildes and may be used in studies on human subjects, professionally exposed to high intensity fields.

Adult↗
PubMedDate not supplied

[Biological action of electromagnetic fields of 4 MHz decametric waves].

Exposure to the amplitude-modulated electromagnetic field, 4 MHZ, 400, 200, and 100 V/m over two months for 16 hours a day was found out to bring low the adaptation potential of a number of bodily physiological systems in animals (non-linebred rats). Changes in the brain functional activity, cell-bound, and humoral immunity were ascertained to be the structural-and-functional basis of reorganization of physiological prosesses.

Afferent Pathways↗
PubMedDate not supplied

The effect of pulsed electromagnetic field (Diapulse) on cellular systems.

The effect of a 27.12 MHz pulsed electromagnetic field (Diapulse) on microbial growth is investigated. A strain of K 12 E. coli grown in complete Pennassay medium is subjected to Diapulse action for 30 min, at 8 hrs and 12 hrs of growth. In this experimental set-up, designed to be closed to the physiological conditions of open wounds, the Diapulse action does not promote any increase of cell population, indicating the safety of this type of therapy for wound healing process. The same K 12 E. coli strain grown in Pennassay medium for 2 hours is inoculated into a minimal growth medium and the lagless exponential growth thus obtained is followed by a spectrophotometric method. Diapulse field is applied to this lagless phase of cellular cultures at 30, 60, and 90 minutes after inoculation. A slight increase in the number of cells was observed at 2 and 4 hours after the Diapulse application, when the cultures were previously subjected to Diapulse action between the period of 60 and 90 minutes of their growth. A possible molecular mechanism for these effects is discussed.

Cells, Cultured↗
PubMedDate not supplied

[Controlled effect of an impulse electromagnetic field on the central nervous system].

Faint influences of impulses (1 ms) electromagnetic fields (173 A/m) with dynamic frequency-impulse modulation, which is regulated by feedback from electrocorticogram, and influences with fixed frequency of impulses run infra-low range affect on changing of current function state of central nervous system in different ways, is established. The white rats in the sleep-wake cycle were used in experiments. Besides, the first regimen of influence is more effective for changing of character of bioelectrical activity of cortex of head brain. The second one-for support of current processes of synchronization.

Animals↗
PubMed1992

Stereotactic microsurgical resection of intracranial tumors using the electromagnetic field focusing system.

The intense heat produced at the tip of the electromagnetic field focusing (EFF) probe at its point of contact with tissue can cut and vaporize tissue and coagulate blood vessels. As the probe is shaped like a bayonet and has a diameter of 0.3 mm at its tip, it can be used on deep structures through narrow openings, making it ideal for stereotactic craniotomy. Thirteen stereotactic craniotomy procedures using the EFF system were performed. Locations of the lesions were deep in the cerebrum, cerebellum and in the lateral ventricle. The system proved efficient with reduced blood loss and unobstructed view of deep structures. No complications resulted from the use of the system.

Brain Neoplasms↗
PubMed2004

Sleep under exposure to high-frequency electromagnetic fields.

The controversy about potential health hazards associated with the exposure to electromagnetic fields (EMF) has been recently stimulated by the increasing use of mobile telecommunication devices. Attention has focused here on non-thermal effects of low-level high-frequency radiation, which does not lead to a heating of tissue. Scientific literature on the effects of high-frequency EMFs on sleep is reviewed. The epidemiological studies provide no evidence that sleep disturbances are a relevant complaint under exposure to such fields. Recent sleep laboratory studies have revealed a number of slight effects. Despite their heterogeneity, there seems to be some consistency regarding a slight sleep-promoting effect and an increase of the alpha power of the sleep EEG induced by high-frequency EMFs. However, for both the epidemiological and sleep laboratory studies, the database concerning sleep is up to now very limited. At the present level of knowledge, no final conclusions can be drawn from the available data concerning potential health hazards. Although there seem to be some biological effects, these do not provide evidence for any adverse health consequences. However, further research is needed for a better understanding of the interaction between EMFs and the sleep process.

Cell Membrane↗
PubMed2000

[Occupational exposure to electromagnetic fields and its health effects in electric energy workers].

Power frequency (50 to 60 Hz) electromagnetic fields (EMF) are briefly characterised, EMF sources occurring in the electromagnetic industry are discussed, and methods for and problems involved in the evaluation of individual occupational EMF exposure are also presented. The results of certain cohort industrial and case-referent studies indicate slightly enhanced risk of brain cancer and leukaemia in the group under study. The meta-analysis of the results obtained from numerous studies, published recently, showed a relative risk (RR) of 1.1-1.3 for leukaemia, and of 1.1-1.2 for brain cancer. Only a few studies demonstrate a dose-effect relationship for malignant neoplasms which decreases the power of the hypothesis on the cause-effect relationship. Among health effects of EMF exposure in electric utility workers, other than malignant neoplasms, an increased risk of certain diseases of the circulatory and neurological systems has been reported. The difficulty in the assessment of individual exposure is the main problem in evaluating the relationship between EMF exposure and adverse health effects in electric utility workers. We hope to investigate this further.

Brain Neoplasms↗
PubMed2005

Cell type-specific genotoxic effects of intermittent extremely low-frequency electromagnetic fields.

The issue of adverse health effects of extremely low-frequency electromagnetic fields (ELF-EMFs) is highly controversial. Contradictory results regarding the genotoxic potential of ELF-EMF have been reported in the literature. To test whether this controversy might reflect differences between the cellular targets examined we exposed cultured cells derived from different tissues to an intermittent ELF-EMF (50 Hz sinusoidal, 1 mT) for 1-24h. The alkaline and neutral comet assays were used to assess ELF-EMF-induced DNA strand breaks. We could identify three responder (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells), which points to the significance of the cell system used when investigating genotoxic effects of ELF-EMF.

Animals↗
PubMed2001

Long-lasting (fatiguing) activity of isolated muscle fibres influenced by microwave electromagnetic field.

The study aims to clarify the effect of exposure to microwave electromagnetic field (MMW) on muscle fibre fatigue. Repetitive stimulation with interstimulus interval of 200 ms was applied on isolated frog muscle fibre to evoke intracellular action potentials and twitch contractions. After their recording muscle fibre preparation was moved in a Petri dish with radius of 28 mm on open air for one hour exposure to continuous MMW with frequency of 2.45 GHz and power density of 20 mW/cm2. Then it was again moved in the chamber with non irradiated Ringer's solution at controlled temperature for the repeated records. After MMW exposure the changes in amplitude and time parameters characterizing fatigue were attenuated and delayed vs. controls. The twitch amplitude curve described an drastic fall in the first 5 sec followed by an increase and next decrease. MMW (2.45 GHz) have a specific, non-thermal influence on muscle fibre activity resulting in some resistance to fatigue.

Action Potentials↗
PubMed1990

[The effect of a pulsed electromagnetic field on the hemodynamics of eyes with glaucoma].

The influence of pulse electromagnetic field (PEMF) on hemodynamics of the eye in open-angle glaucoma has been studied by means of a method and a device proposed at the Filatov Institute. The PEMF characteristics are: impulse frequency--50 Hz, exposition--0,02 sec., impulse shape--square, rate of impulse rise--4.10(4) c rate of magnetic induction rise--2.10(4) mT/c, amplitude value of magnetic induction at the impulse height--9.0--8.5 mT, duration of the procedure--7 min., a course--10 sessions. Observations over 150 patients (283 eyes) with latent, initial and advanced glaucoma have shown a positive influence of PEMF on hemodynamics of a glaucomatous eye: a rise of rheographic coefficient and relative volume pulse in 87,99 and 81,63%, respectively. The degree of the rise and restoration frequency of rheographic values of the glaucomatous eye under the influence of PEMF to the age norm was more expressed at initial stages of the glaucomatous process (latent and initial glaucoma).

Aged↗
PubMed1999

Effects of electromagnetic fields on photophasic circulating melatonin levels in American kestrels.

Birds reproduce within electromagnetic fields (EMFs) from transmission lines. Melatonin influences physiologic and behavioral processes that are critical to survival, and melatonin has been equivocally suppressed by EMFs in mammalian species. We examined whether EMFs affect photophasic plasma melatonin in reproducing adult and fledgling American kestrels (Falco sparverius), and whether melatonin was correlated with body mass to explain previously reported results. Captive kestrel pairs were bred under control or EMF conditions for one (short-term) or two (long-term) breeding seasons. EMF exposure had an overall effect on plasma melatonin in male kestrels, with plasma levels suppressed at 42 days and elevated at 70 days of EMF exposure. The similarity in melatonin levels between EMF males at 42 days and controls at 70 days suggests a seasonal phase-shift of the melatonin profile caused by EMF exposure. Melatonin was also suppressed in long-term fledglings, but not in short-term fledglings or adult females. Melatonin levels in adult males were higher than in adult females, possibly explaining the sexually dimorphic response to EMFs. Melatonin and body mass were not associated in American kestrels. It is likely that the results are relevant to wild raptors nesting within EMFs.

Animals↗
PubMed1996

Experimental study of the effects of radiofrequency electromagnetic fields on animals with soft tissue wounds.

The effect of radio frequency electromagnetic fields (RF EMF) was studied on Wistar rats with excised full-thickness dermal wounds in the interscapular region. The wounded regions of experimental animals were subjected to EMF for 30 min daily during the first 5 days after wound infliction. Control animals received no treatment. We used RF EMF with (1) frequency 53.53 GHz without modulation; (2) frequency 42.19 GHz without modulation; (3) frequency 42.19 GHz, but with a frequency modulation band 200-MHz wide. On the 7th day the animals were terminated and the granulation-fibrous tissue (GFT) developed in the wounds was subjected to complex quantitative biochemical analysis. RF EMF without frequency modulation decreased the amounts of glycoprotein macromolecules, diminishing the inflammatory exudation. In striking contrast, under the influence of RF EMF with frequency modulation, hexoses and especially sialic acid concentrations were significantly elevated (P < 0.001). This indicated intensification of exudative phenomena. As a consequence of inflammation inhibition in the treatment without frequency modulation, the total collagen accumulation was lowered. However, when frequency was modulated, the inflammatory phenomena were intensified, and pronounced accumulation of collagenous proteins was noted. Thus, our experiments confirm the effects of non-thermal EMF on the reparative-proliferative processes of animals with soft tissue wounds.

Animals↗
PubMed2005

Timing of pulsed electromagnetic field stimulation does not affect the promotion of bone cell development.

Pulsed electromagnetic field (PEMF) devices have been used clinically to promote the healing of surgically resistant fractures in vivo. However, there is a sparsity of data on how the timing of an applied PEMF effects the osteogenic cells that would be present within the fracture gap. The purpose of this study was to examine the response of osteoblast-like cells to a PEMF stimulus, mimicking that of a clinically available device, using four protocols for the timing of the stimulus. The PEMF signal consisted of a 5 ms pulse burst (containing 20 pulses) repeated at 15 Hz. Cultures of a human osteosarcoma cell line, SaOS-2, were exposed to the four timing protocols, each conducted over 3 days. Protocol one stimulated the cells for 8 h each day, protocol two stimulated the cells for 24 h on the first day, protocol three stimulated the cells for 24 h on the second day, and protocol four stimulated the cells for 24 h on the third day. Cells were seeded with either 25,000 or 50,000 cells/well (24-well cell culture plates). All assays showed reduced proliferation and increased differentiation (alkaline phosphatase activity) in the PEMF stimulated cultures compared with the control cultures, except for protocol four alkaline phosphatase measurements. No clear trend was observed between the four protocols; however this may be due to cell density. The results indicated that an osteoblast-like cell line is responsive to a 15 Hz PEMF stimulus, which will stimulate the cell line to into an increasing state of maturity.

Bone Development↗
PubMed1996

Pulsed electromagnetic fields influence hyaline cartilage extracellular matrix composition without affecting molecular structure.

Pulsed electromagnetic fields (PEMF) influence the extracellular matrix metabolism of a diverse range of skeletal tissues. This study focuses upon the effect of PEMF on the composition and molecular structure of cartilage proteoglycans. Sixteen-day-old embryonic chick sterna were explanted to culture and exposed to a PEMF for 3 h/day for 48 h. PEMF treatment did not affect the DNA content of explants but stimulated elevation of glycosaminoglycan content in the explant and conserved the tissue's histological integrity. The glycosaminoglycans in sterna exposed to PEMF were indistinguishable from those in controls in their composition of chondroitin sulfate resulting from chondroitinase ABC digestion. Specific examination with [35S]-sulfate labels showed that PEMF treatment significantly suppressed both the degradation of pre-existing glycosaminoglycans biosynthetically labeled in ovo and the synthesis of new [35S]-sulfated glycosaminoglycans. The average size and aggregating ability of pre-existing and newly synthesized [35S]-sulfated proteoglycans extracted with 4 M guanidinium chloride from PEMF-treated cartilage explants were identical to controls. The chain length and degree of sulfation of [35S]-sulfated glycosaminoglycans also were identical in control and PEMF-treated cultures. PEMF treatment also reduced the amount of both unlabeled glycosaminoglycans and labeled pre-existing and newly synthesized [35S]-sulfated glycosaminoglycans recovered from the nutrient media. [35S]-Sulfated proteoglycans released to the media of both control and PEMF-treated cultures were mostly degradation products although their glycosaminoglycan chain size was unchanged. These results demonstrate that exposure of embryonic chick cartilage explants to PEMF for 3 h/day maintains a balanced proteoglycan composition by down-regulating its turnover without affecting either molecular structure or function.

Animals↗
PubMed2005

Influence of exposure to electromagnetic field on the cardiovascular system.

1 We examined whether extremely low frequency electromagnetic fields (ELF-EMF) affect the basal level of cardiovascular parameters and influence of drugs acting on the sympathetic nervous system. 2 Male rats were exposed to sham control and EMF (60 Hz, 20 G) for 1 (MF-1) or 5 days (MF-5). We evaluated the alterations of blood pressure (BP), pulse pressure (PP), heart rate (HR), and the PR interval, QRS interval and QT interval on the electrocardiogram and dysrhythmic ratio in basal level and dysrhythmia induced by beta-adrenoceptor agonists. 3 In terms of the basal levels, there were no statistically significant differences among control, MF-1 and MF-5 in PR interval, QRS interval, mean BP, HR and PP. However, the QT interval, representing ventricular repolarization, was significantly reduced by MF-1 (P < 0.05). 4 (-)-Dobutamine (beta1-adrenoceptor-selective agonist)-induced tachycardia was significantly suppressed by ELF-EMF exposure in MF-1 for the increase in HR (DeltaHR), the decrease in QRS interval (DeltaQRS) and the decrease in QT (DeltaQT) interval. Adrenaline (nonselective beta-receptor agonist)-induced dysrhythmia was also significantly suppressed by ELF-EMF in MF-1 for the number of missing beats, the dysrhythmic ratio, and the increase in BP and PP. 5 These results indicated that 1-day exposure to ELF-EMF (60 Hz, 20 G) could suppress the increase in HR by affecting ventricular repolarization and may have a down-regulatory effect on responses of the cardiovascular system induced by sympathetic agonists.

Animals↗
PubMed2005

Cardiac torsion and electromagnetic fields: the cardiac bioinformation hypothesis.

Although in physiology the heart is often referred to as a simple piston pump, there are in fact two additional features that are integral to cardiac physiology and function. First, the heart as it contracts in systole, also rotates and produces torsion due to the structure of the myocardium. Second, the heart produces a significant electromagnetic field with each contraction due to the coordinated depolarization of myocytes producing a current flow. Unlike the electrocardiogram, the magnetic field is not limited to volume conduction and extends outside the body. The therapeutic potential for interaction of this cardioelectromagnetic field both within and outside the body is largely unexplored. It is our hypothesis that the heart functions as a generator of bioinformation that is central to normative functioning of body. The source of this bioinformation is based on: (1) vortex blood flow in the left ventricle; (2) a cardiac electromagnetic field and both; (3) heart sounds; and (4) pulse pressure which produce frequency and amplitude information. Thus, there is a multidimensional role for the heart in physiology and biopsychosocial dynamics. Recognition of these cardiac properties may result in significant implications for new therapies for cardiovascular disease based on increasing cardiac energy efficiency (coherence) and bioinformation from the cardioelectromagnetic field. Research studies to test this hypothesis are suggested.

Animals↗
PubMed1985

The effect of pulsed electromagnetic fields on bone cell metabolism and calvaria resorption in vitro, and on calcium metabolism in the live rat.

The effects of three pulsed electromagnetic fields were investigated on bone cells and calvaria in culture, and on calcium metabolism in the live rat. No significant effect was seen on: 1) the proliferation of calvaria cells in culture; 2) alkaline phosphatase level, lactic acid release and collagen synthesis by confluent calvaria cells, with the exception of one pulse which produced a small increase in the latter when expressed as DNA; 3) resorption of calvaria in culture; 4) intestinal absorption, urinary excretion and net balance of calcium, bone formation and bone resorption in the live rat.

Alkaline Phosphatase↗
PubMed1989

Extremely low frequency pulsed electromagnetic fields increase cell proliferation in lymphocytes from young and aged subjects.

The effect of the in vitro exposure to extremely low frequency pulsed electromagnetic fields (PEMFs) on the proliferation of human lymphocytes from 24 young and 24 old subjects was studied. The exposure to PEMFs during a 3-days culture period or during the first 24 hours was able to increase phytohaemagglutinin-induced lymphocyte proliferation in both groups. Such effect was greater in lymphocytes from old people which showed a markedly reduced proliferative capability and, after PEMF exposure, reached values of 3H-TdR incorporation similar to those of young subjects. The relevance of these data for the understanding and the reversibility of the proliferative defects in cells from aged subjects and for the assessment of risk related to the environmental exposure to PEMFs has to be considered.

Adult↗