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Experiments showing that electromagnetic fields can be used to treat inflammatory diseases.

While it is well known that electromagnetic fields (EMFs) can induce repair of non-healing bone fractures, EMF therapy remains confined to orthopedic clinics mainly because the biological and physical mechanisms underlying the therapy are unknown. However, it is generally believed that non-invasive, EMF therapy might have a broad, albeit currently unrecognized clinical potential. In support of this view, we report that 0.1 mT, 60 Hz EMFs induce a 20% mean-increase in anti-CD3 binding to T cell receptors (TcRs) of Jurkat cells, a T lymphocyte cell line. Additionally, we show that 60 Hz sinusoidal EMFs and a commercial bone healing EMF modulate signal transduction pathways that regulate lymphocyte proliferation and that are normally triggered by activating the Jurkat TcR. Similar EMF effects are shown in human peripheral blood lymphocytes (hPBLs), exposed to EMFs in culture and in rat PBLs, when donor animals are exposed to a bone healing field (21 days, 4 hr/day). Although we do not yet satisfactorily understand the differences we obtain in cell and animal based experiments, our findings clearly demonstrate that EMFs can regulate lymphocyte proliferation in vitro and in vivo. Since T cells are key modulators of inflammation, the development of EMF based therapeutic devices to regulate their activity can be expected to provide important tools to treat numerous human inflammatory diseases such as psoriasis and arthritis.

Animals↗

[Exposure to VHF and UHF electromagnetic fields among workers employed in radio and TV broadcast centers. I. Assessment of exposure].

Nowadays, radio and television have become one of the areas of the human technical activity that develops most rapidly. Also ultra-short waves of VHF (30-300 MHz) and UHF (0.3-3 GHz) bands have proved to be the most important carriers of radio and TV-programs. In Poland, a network of radio and TV broadcast centers (RTCN) with high (over 200 m) masts was set up in the 1960s and 1970s. These centers concentrate the majority of stations broadcasting national and local programs (for areas within the RTCN range). At present, the RTCN established several decades ago are equally important. The assessment of the exposure to electromagnetic fields among workers of multi-program broadcast stations is complicated and feasible only to a certain degree of approximation because of changing conditions of exposure in individual stations during their long history, resulting from the changing numbers and types of transmitters installed. In this work, the method of retrospective estimation of exposure dose is described, and the results of the assessment carried out at three kinds of typical RTCN are discussed. The results of the analysis indicate that the workers of RTCN are exposed primarily to electromagnetic fields of VHF and UHF bands, but this exposure may be considered as admissible, hence it should not exert an adverse effect on the workers' health.

Electromagnetic Fields↗

Effects of static electromagnetic fields on characteristics of MG-63 osteoblasts grown in culture.

The effects of static electromagnetic fields (SEFs) on MG-63, a human osteoblast cell-line, were investigated. We examined proliferation, proline uptake and gene expression in an SEF approximately 1/728th the intensity of those previously reported. Cells were placed within an SEF apparatus (average field intensity of 0.618mT) with appropriate controls. Proliferation was measured by 3H-thymidine incorporation and showed a 34% decrease in cells exposed to SEF (P = .0001; N = 3). Proline, a major component of collagen necessary for bone formation by osteoblasts, incorporation was reduced 37% (P = 0.006; N = 3). Reverse-transcription-polymerase chain reaction revealed that collagen I, alkaline phosphatase, parathyroid hormone-receptor, and osteocalcin mRNA's were down regulated with the low intensity SEF. Exposure to very low SEFs affects the MG-63 osteoblasts in a manner that may be detrimental to bone formation.

Bone Neoplasms↗

Cell physiological effects of radiofrequency electromagnetic fields.

Ovarian and body cavity eggs from R. temporaria were exposed to radiofrequency (rf) electromagnetic fields in the frequency range 10-27 MHz with specific absorption rates (SAR) up to 800 W/kg. The effect of the exposure was investigated by measurement of the water-related cell physiological parameters, isotopic and osmotic water membrane permeability and density of the egg cells. Only the osmotic water permeability, Pf, of ovarian eggs was significantly altered. A decrease of about 30% was seen for SARs of 50 W/kg and exposure times up to 2 h. Tests ruled out that the effect was due to temperature increase during the exposure. The observed decrease of Pf was most likely due to cloudy swelling of the egg cytoplasm resulting from the rf irradiation.

Animals↗

Circadian neuroendocrine physiology and electromagnetic field studies: precautions and complexities.

The suppression of melatonin by exposure to low frequency electromagnetic fields (EMFs) 'the melatonin hypothesis'. has been invoked as a possible mechanism through which exposure to these fields may result in an increased incidence of cancer. While the effect of light on melatonin is well established, data showing a similar effect due to EMF exposure are sparse and, where present, are often poorly controlled. The current review focuses on the complexities associated with using melatonin as a marker and the dynamic nature of normal melatonin regulation by the circadian neuroendocrine axis. These are issues which the authors believe contribute significantly to the lack of consistency of results in the current literature. Recommendations on protocol design are also made which, if followed, should enable researchers to eliminate or control for many of the confounding factors associated with melatonin being an output from the circadian clock.

Animals↗

The effect of electromagnetic field exposure on the formation of DNA lesions.

In an attempt to determine whether electromagnetic field (EMF) exposure might lead to DNA damage, we exposed SnCl2-treated pBR322 plasmids to EMF and analysed the resulting conformational changes using agarose gel electrophoresis. An EMF-dependent potentiation of DNA scission (i.e. the appearance of relaxed plasmids) was observed. In confirmation of this, plasmids pre-exposed to EMF also were less capable of transforming Escherichia coli. The results indicate that EMF, in the presence of a transition metal, is capable of causing DNA damage. These observations support the idea that EMF, probably through secondary generation of reactive oxygen species, can be clastogenic and provide a possible explanation for the observed correlation between EMF exposure and the frequency of certain types of cancers in humans.

DNA Damage↗

The effect of electromagnetic field stimulation on corticosteroids-inhibited intestinal wound healing.

Electromagnetic field (EMF) stimulation has been used successfully in the clinical setting to promote healing of ununited fractures. In a few studies, EMF stimulation enhanced soft tissue healing. To investigate the effect of EMF stimulation on intestinal wound healing in normal rats and in those treated with corticosteroids, 80 Wistar rats received twice-daily injections of either saline dexamethasone (0.1 mg/kg/day for 2 weeks. Animals then underwent creation of single-layer, inverting small intestine anastomoses. All injections were continued postoperatively. Animals were grouped as intestinal anastomoses; intestinal anastomoses plus EMF stimulation; intestinal anastomoses plus dexamethasone; and intestinal anastomoses plus dexamethasone plus EMF. On postoperative days 7 and 14, the anastomosed intestines were removed and the tensile strength (TS) and hydroxyproline (OH-P) contents measured. EMF stimulation significantly increased intestinal wound healing in normal animals by the 7th and 14th day. Corticosteroids significantly impaired the healing of the small intestine anastomoses, with decreased TS and OH-P contents after the first and second weeks. However, EMF stimulation significantly reversed this inhibitory effect.

Animals↗

Effects of electromagnetic fields on the motion of Euglena gracilis.

The orientation behavior of Euglena gracilis cultures in electromagnetic fields is shown to agree with the predictions of a model involving only a passive mechanism. The increase in Euglena motor activity with increasing field intensity is demonstrated by measuring various motion parameters by the laser scattering technique. The effect of electric field on the speed of Euglenas is compared with that of temperature. We conclude that the electric field warms up the culture, thus inducing an increase in cell motility.

Cell Movement↗

DNA damage in frog erythrocytes after in vitro exposure to a high peak-power pulsed electromagnetic field.

Till the present time, the genotoxic effects of high peak-power pulsed electromagnetic fields (HPPP EMF) on cultured cells have not been studied. We investigated possible genotoxic effects of HPPP EMF (8.8 GHz, 180 ns pulse width, peak power 65 kW, repetition rate 50 Hz) on erythrocytes of the frog Xenopus laevis. We used the alkaline comet assay, which is a highly sensitive method to assess DNA single-strand breaks and alkali-labile lesions. Blood samples were exposed to HPPP EMF for 40 min in rectangular wave guide. The specific absorption rate (SAR) calculated from temperature kinetics was about 1.6 kW/kg (peak SAR was about 300 MW/kg). The temperature rise in the blood samples at steady state was 3.5 +/- 0.1 degrees C. The data show that the increase in DNA damage after exposure of erythrocytes to HPPP EMF was induced by the rise in temperature in the exposed cell suspension. This was confirmed in experiments in which cells were incubated for 40 min under the corresponding temperature conditions. The results allow us to conclude that HPPP EMF-exposure at the given modality did not cause any a-thermal genotoxic effect on frog erythrocytes in vitro.

Animals↗

[Effect of pulsed electromagnetic fields (PEMF) on osteoblast-like cells. Alterations of intracellular Ca2+].

Low-energy electromagnetic fields pulsed at frequencies of 60-90 Hz significantly increase healing of chronic fracture nonunions in man. These fields are effective at tissue current levels as low as several orders of magnitude lower than those required for transmembrane depolarization of normal cells. In this study, the effects of PEMF on culture of rat osteoblast-like cells have been examined. The PEMF promoted the growth of these cells, were also found to increase the basal level of [Ca2+]i, and to decrease the responses towards epidermal growth factor (EGF) and serum, when the degree of response was based on the intracellular Ca2+ transient. These effects of PEMF were mimicked by 12-O-tetradecanoyl phorbol 13-acetate (TPA), a potent activator of protein kinase C. Pretreatment of TPA enhanced the cell growth and suppressed the intracellular Ca2+ transient induced with EGF and then serum to about 170% of the control. Then, present study investigated how the PEMF and TPA modulate EGF receptors of these cells. Both PEMF and TPA decreased the level of EGF binding to these cells down to about 65% and 75%, respectively. Scatchard analysis revealed the decrease of EGF receptor without a significant change in the affinity for EGF by both. In conclusion, it was indicated that PEMF acts at cell membrane and modulates the receptors which is essential for cell growth and DNA synthesis.

Animals↗

Effects of electromagnetic fields and gender on neurotransmitters and amino acids in rats.

Epidemiological studies have linked electromagnetic field (EMF) exposure to certain forms of cancer, however only limited laboratory evidence supports a connection between EMF and biological effects. In the present study we exposed male and female rats to low level, 1000 milli-Gauss (mGs), direct current EMF generated with Helmholtz coils for 1 mo or 4 mo. The effects of these EMF exposures on regional brain neurotransmitter metabolism and circulating amino acid concentrations were determined. After 1 mo of EMF exposure the concentration of serotonin was elevated in the hypothalamus of male rats. Levels of the dopamine metabolite, 3-methoxytyramine, were increased in the corpus striatum of male and female rats that were exposed to EMF for 1 mo. Hypothalamic concentration of norepinephrine was elevated in both groups of male rats, as compared to respective female groups, but was not affected by EMF. Similarly, levels of tyrosine were increased in hypothalamus, corpus striatum and nucleus accumbens of male rats, but were not affected by EMF exposure. Following 4 mo of EMF exposure, no significant effect of EMF was observed. Significant sex differences in plasma amino acid concentrations were observed in both studies, with female rats exhibiting decreases in a majority of the amino acids measured. These results are suggestive that short-term exposure may cause small alterations in neurotransmitter metabolism and in circulating amino acids, which dissipate when exposure duration is increased.

Amino Acids↗

Responses of human MG-63 osteosarcoma cell line and human osteoblast-like cells to pulsed electromagnetic fields.

We have studied the effects of low-energy, low-frequency pulsed electromagnetic fields (PEMF) on cell proliferation, in both human osteoblast-like cells obtained from bone specimens and in human MG-63 osteosarcoma cell line. Assessment of osteoblastic phenotype was performed both by immunolabeling with antiosteonectin antibody and by verifying the presence of parathyroid hormone receptors. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmholtz coils powered by a pulse generator (1.3 ms, 75 Hz) for different periods of time. [3H]Thymidine incorporation was used to evaluate cell proliferation. Since it had previously been observed that the osteoblast proliferative response to PEMF exposure may also be conditioned by the presence of serum in the medium, experiments were carried out at different serum concentrations. [3H]Thymidine incorporation increases in osteoblast-like cells, when they are exposed to PEMF in the presence of 10% fetal calf serum (FCS). The greatest effect is observed after 24 hours of PEMF exposure. No effects on cell proliferation are observed when osteoblast-like cells are exposed to PEMF in the presence of 0.5% FCS or in a serum-free medium. On the other hand, PEMF-exposed MG-63 cells show increased cell proliferation either at 10% FCS, 0.5% FCS and in serum-free medium. Nevertheless, the maximum effect of PEMF exposure on MG-63 cell proliferation depends on the percentage of FCS in the medium. The higher the FCS concentration, the faster the proliferative response to PEMF exposure. Our results show that, although MG-63 cells display some similarity with human bone cells, their responses to PEMF's exposure are quite different from that observed in normal human bone cells.

Adult↗

Electromagnetic hypersensitivity (EHS) and subjective health complaints associated with electromagnetic fields of mobile phone communication--a literature review published between 2000 and 2004.

Literature published between 2000 to 2004 concerning electromagnetic fields (EMF) of mobile communication and electromagnetic hypersensitivity (EHS) or unspecific symptoms of ill health, respectively, is reviewed. Basically, literature from established databases was systematically searched for. For each study, the design and quality were evaluated by means of a criteria list in order to judge evidence for causality of exposures on effects. Finally, 13 studies of sufficient quality were considered for this review. In only one provocation study, individuals with self-reported electromagnetic hypersensitivity were exposed to EMF. Their perception of field status was no better than would have been expected by chance. Results of five randomised cross-over studies on impaired well-being due to mobile phone exposure were contradictory. Even though these studies would allow more reliable exposure assessment, they are limited due to short exposure period and the small study size. No firm conclusion could be drawn from a few observational epidemiological studies finding a positive association between exposure and unspecific symptoms of ill health due to methodological limitations. Causality of exposure and effect was not derivable from these cross-sectional studies as field status and health complaints were assessed at the same time. In addition, exposure assessment has not been validated. In conclusion, based on the limited studies available, there is no valid evidence for an association between impaired well-being and exposure to mobile phone radiation presently. However, the limited quantity and quality of research in this area do not allow to exclude long-term health effects definitely.

Anxiety↗

The relationship between flash evoked potentials and evoked amplitude modulation patterns of an applied UHF electromagnetic field in the rat.

Pilot studies demonstrate evidence that the electrophysiological processes associated with flash stimulation of the central nervous system (CNS) of rats, as seen in the recordings of visual-evoked potentials, may also be detectable using an ultrahigh frequency electromagnetic field (UHFEMF). Patterns of amplitude modulation of an applied UHFEMF, when recorded and averaged, show strong correlations with simultaneously recorded evoked potentials. The data support the hypothesis that the UHFEMF amplitude is altered in a dynamic fashion by the tissue's electrophysiological processes that are involved with the generation of CNS electric fields.

Animals↗

Preliminary study of quantitative aspects and the effect of pulsed electromagnetic field treatment on the incorporation of equine cancellous bone grafts.

The quantitative aspects of equine cancellous bone graft incorporation and the possibility of influencing graft incorporation by daily exposure to a pulsed electromagnetic field (PEMF) was studied in eight yearling ponies. In order to be able to quantify formative aspects of graft remodelling, a double and treble tetracycline intravital labelling technique was used. Intravital radiographs were obtained at regular intervals throughout the trial, but were found to be of little assistance in assessing any differences between stimulated and non-stimulated grafts. The ponies were humanely destroyed at regular intervals between nine and 241 days after installation of the graft. Light microscopy and fluorescent light microscopy were used to evaluate quantitative aspects of graft incorporation and to compare PEMF-stimulated grafts with control grafts. There was a small but statistically significant effect of PEMF-stimulation on cancellous bone graft incorporation. In view of this, these observations can only be considered as indicative of a possible trend, but should encourage further studies using different signal modalities.

Animals↗

Effect of external pulsing electromagnetic fields on the healing of soft tissue.

Since fibroblast behavior in bone healing can be altered electrically, it is plausible to hypothesize that fibroblast proliferation and function in soft tissue healing also would respond to an electromagnetically induced pulse. Reports of clinical impressions of accelerated closure of chronic skin wounds overlying areas being treated for nonunion have produced support for this hypothesis, but experimental data have been lacking. This study was designed to evaluate the effect of pulsed electromagnetic fields (PEMFs) with clinically employed wave-form parameters on the rate of closure of excisional wounds in normal animals and those with steroid retarded wound healing. Four groups, each containing 12 PEMF-treated rats and 12 control rats, were given different field exposures and two groups were treated with methylprednisolone. The wound areas were measured and tissue was harvested for histological examination at intervals for 28 days after wounding. There was no difference in the gross or microscopical appearance of wounds in each active group and its respective control group. Differences in the number of counted fibroblasts were not significant (p less than 0.5), and wound contraction and epithelialization proceeded at the same rate (t-test for equality of means, power = 90%). Electrical PEMF stimulation with the driving pulse used clinically for nonunion bony repair did not affect soft tissue healing in this model. No experimental support is provided for the reports of accelerated skin healing within therapeutic fields. It is possible that different wave-form characteristics are needed to provoke a response in soft tissue.

Animals↗

Effect of low-level, 60-Hz electromagnetic fields on human lymphoid cells: I. Mitotic rate and chromosome breakage in human peripheral lymphocytes.

Dividing human peripheral lymphocytes from 10 normal adults (5 males and 5 females) were exposed in vitro to low level 60-Hz electromagnetic fields for 69 hours. The current density of the electrical field was 30 microA/cm2, while the magnetic field was either 1 or 2 gauss. The cytological endpoints measured were mitotic rate and chromosome breakage. No statistically significant differences, indicative of a field effect, were observed between treated and control cells whether exposed to an electric field, a magnetic field, or to various combinations of the two.

Adult↗

Extremely low frequency electromagnetic fields and cancer: the epidemiologic evidence.

This paper reviews the epidemiologic evidence that low frequency electromagnetic fields generated by alternating current may be a cause of cancer. Studies examining residential exposures of children and adults and studies of electrical and electronics workers are reviewed. Using conventional epidemiologic criteria for inferring causal associations, including strength and consistency of the relationship, biological plausibility, and the possibility of bias as an explanation, it is concluded that the evidence is strongly suggestive that such radiation is carcinogenic. The evidence is strongest for brain and central nervous system cancers in electrical workers and children. Weaker evidence supports an association with leukemia in electrical workers. Some evidence also exists for an association with melanoma in electrical workers. Failure to find consistent evidence of a link between residential exposures and adult cancers may be attributable to exposure misclassification. Studies so far have used imperfect surrogates for any true biologically effective magnetic field exposure. The resulting exposure misclassification has produced relative risk estimates that understate any true risk.

Adolescent↗