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PubMedDate not supplied

[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.

Adolescent↗
PubMed2000

[Programmed cell death as a biological function of electromagnetic fields at a frequency of (50/60 Hz)--review].

Apoptosis as physiological or programmed cellular death, and necrosis as pathological cellular death are two ways by which cells die. Recent data confirm that oxygen free radicals can be the mediators of apoptosis via signalling pathways in the cell. External magnetic fields are known to affect radical pair recombination and they may increase the concentration of oxygen free radicals in living cells. Therefore, it has been suggested that physical agents, such as electromagnetic fields of power-line frequency, could exert an effect on apoptosis via signalling pathways and oxygen free radicals.

Animals↗
PubMedDate not supplied

Drug resistance modification using pulsing electromagnetic field stimulation for multidrug resistant mouse osteosarcoma cell line.

Multidrug resistance (MDR) is one of the major problems in osteosarcoma chemotherapy. Therefore, methods of overcoming MDR are urgently needed. In this study, we investigated the effects of pulsing electromagnetic field stimulation (PEMFs) on a MDR murine osteosarcoma cell line which strongly expresses P-glycoprotein (P-gp). To assess the reversal effects of PEMFs on doxorubicin (DOX) resistance, MTT assay was applied. Viable cells were assessed by the trypan blue exclusion test. Fluorescence intensity of DOX binding to nuclear DNA of each cell was measured using a cytofluorometer. Changes in P-gp expression in each cell were detected by the indirect immunofluorescence method using an antibody to Pgp. PEMFs increased DOX binding ability to nuclear DNA and inhibited cell growth, although it had no significant effect on P-gp expression. These findings indicated that PEMFs reversed the DOX resistance of the MOS/ADR1 cells by inhibiting P-gp function. The results suggested that PEMFs may be useful as a local treatment for MDR osteosarcoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Effects of high-frequency electromagnetic fields emitted from card readers of access control systems on electronic pocket dosimeters.

High-frequency electromagnetic fields in the 120 kHz band emitted from card readers for access control systems caused abnormally high doses on electronic pocket dosimeters (EPDs). All EPDs recovered their normal performance by resetting after the exposure ceased. The electric and magnetic immunity levels of the EPDs were estimated by using the distances needed to prevent electromagnetic interference.

Journal Article↗
PubMed2006

Radiofrequency electromagnetic fields emitted from base stations of DECT cordless phones and the risk of glioma and meningioma (Interphone Study Group, Germany).

The objective of this study was to test the hypothesis that exposure to continuous low-level radiofrequency electromagnetic fields (RF EMFs) increases the risk of glioma and meningioma. Participants in a population-based case-control study in Germany on the risk of brain tumors in relation to cellular phone use were 747 incident brain tumor cases between the ages of 30 and 69 years and 1494 matched controls. The exposure measure of this analysis was the location of a base station of a DECT (Digital Enhanced Cordless Telecommunications) cordless phone close to the bed, which was used as a proxy for continuous low-level exposure to RF EMFs during the night. Estimated odds ratios were 0.82 (95% confidence interval: 0.29-2.33) for glioma and 0.83 (0.29-2.36) for meningioma. There was also no increasing risk observed with duration of exposure to DECT cordless phone base stations. Although the study was limited due to the small number of exposed subjects, it is still a first indication that residential low-level exposure to RF EMFs may not pose a higher risk of brain tumors.

Adult↗
PubMed2003

Radio frequency electromagnetic fields: cancer, mutagenesis, and genotoxicity.

We present critiques of epidemiologic studies and experimental investigations, published mostly in peer-reviewed journals, on cancer and related effects from exposure to nonionizing electromagnetic fields in the nominal frequency range of 3 kHz to 300 GHz of interest to Subcommittee 4 (SC4) of the International Committee on Electromagnetic Safety (ICES). The major topics discussed are presented under the headings Epidemiologic and Other Findings on Human Exposure, Mammals Exposed In Vivo, Mammalian Live Tissues and Cell Preparations Exposed In Vitro, and Mutagenesis and Genotoxicity in Microorganisms and Fruit Flies. Under each major topic, we present minireviews of papers on various specific endpoints investigated. The section on Epidemiologic and Other Findings on Human Exposure is divided into two subsections, the first on possible carcinogenic effects of exposure from emitters not in physical contact with the populations studied, for example, transmitting antennas and other devices. Discussed in the second subsection are studies of postulated carcinogenic effects from use of mobile phones, with prominence given to brain tumors from use of cellular and cordless telephones in direct physical contact with an ear of each subject. In both subsections, some investigations yielded positive findings, others had negative findings, including papers directed toward experimentally verifying positive findings, and both were reported in a few instances. Further research on various important aspects may resolve such differences. Overall, however, the preponderance of published epidemiologic and experimental findings do not support the supposition that in vivo or in vitro exposures to such fields are carcinogenic.

Animals↗
PubMed1994

Electromagnetic fields and brain tumours: a commentary.

Brain tumours are of different cell types, the commonest being tumours of glia called gliomas. Many etiological factors of gliomas have been suggested and certain industries have been implicated. Several epidemiological studies have linked electromagnetic fields (EMFs) to gliomas. Health effects of EMFs have been studied, both in humans and in experimental animals, mainly with negative findings. Positive experimental evidence linking EMFs to tumours is the effect of EMFs on melatonin production by the pineal gland. Removal of the pineal gland in rats increases the incidence of tumours. Further epidemiological and experimental evidence is required to elucidate this possible link between EMFs and brain tumours.

Brain Neoplasms↗
PubMed1989

A preliminary investigation of the effect of selected electromagnetic field devices on healing of cannon bone osteotomies in horses.

The effect of electrical stimulation by means of selected electromagnetic field devices on healing of cannon bone osteotomies in horses was examined. The defects were created as 3 cm x 1 mm longitudinal osteotomies through the dorsal cortices of the mid-metacarpi/metatarsi of adult horses. This type of defect would asses bone healing in a situation similar to an acute, stable fracture of the cortex. Three electromagnetic devices of different design were tested in three different groups of horses. Healing was evaluated radiographically and histologically. Results showed that osteotomies treated with the electromagnetic devices healed similarly to untreated controls. Our conclusion is that the electromagnetic devices studied did not have a local effect on the repair process of an acute, stable, osseous defect.

Animals↗
PubMed2004

Effect of pulse-burst electromagnetic field stimulation on osteoblast cell activities.

Electric stimulation has been used successfully to treat a wide range of bone disorders. However, the mechanism by which the electric fields can influence the bone cells behavior remains poorly understood. The purpose of this research was to assess the possible mechanism of the stimulatory effect of pulsed electromagnetic field (PEMF) on bone cells. A PEMF with a frequency of 15 Hz (1 G [0.1 mT]; electric field strength 2 mV/cm) were applied to neonatal mouse calvarial bone cell cultures for 14 days. The temporal effects of PEMF on the osteoblasts were evaluated by the status of proliferation, differentiation, mineralization, and gene expression on the 3rd, 5th, 7th, and 14th days of culture. Our results demonstrated that PEMF stimulation significantly increased the osteoblasts' proliferation by 34.0, 11.5, and 13.3% over the control group after 3, 5, and 7 days' culture. Although the alkaline phosphatase (ALP) staining and the mineralization nodules formation did not change, the ALP activity of the bone cells decreased significantly after PEMF stimulation. Under the PEMF stimulation, there was no effect on the extracellular matrix synthesis, while the osteoprotegerin (OPG) mRNA expression was up regulated and the receptor activator of NF-kappaB ligand (RANKL) mRNA expression were down regulated, compared to the control. In conclusion, the treatment by PEMF of osteoblasts may accelerate cellular proliferation, but did not affect the cellular differentiation. The effect of PEMF stimulation on the bone tissue formation was most likely associated with the increase in the number of cells, but not with the enhancement of the osteoblasts' differentiation.

Animals↗
PubMedDate not supplied

[Change in charge of the erythrocyte membrane during exposure to a pulsed electromagnetic field].

By means of hydrophobic anion phenyldicarbaundecaboron electrophoresis in PAA gels and filtration through "Millipore" filters an increase of the total membrane charge and decrease in the amount of membrane-bound proteins (actin, glyceraldehyde-3-phosphatedehydrogenase) after erythrocyte ghosts exposition in pulsed electromagnetic field (PEMF, 1-10 Hz pulse frequency, 24 mTesla) were demonstrated. The effects of PEMF are explained by the changes in the distribution of electrostatic charges near the membrane protein-protein binding sites.

Electromagnetic Fields↗
PubMed2003

Effects of electromagnetic field on bone healing around commercially pure titanium surface: histologic and mechanical study in rabbits.

PURPOSE: The purpose of this pilot study was to evaluate the histologic and mechanical healing process in dental implants under the action of pulsed electromagnetic field (PEMF). MATERIALS AND METHODS: Forty-eight commercially pure implant fixtures were implanted in tibiae metaphysis of 12 New Zealand white rabbits divided into experimental (PEMF) and control groups. A PEMF with pulse width of 85 microseconds and a pulse frequency of 20 Mc was applied for 30 minutes per day. The animals were killed 21 and 42 days after implantation. The mechanical tests were performed in all animals and bone biopsies were prepared for decalcified sections analysis. RESULTS: Mechanical tests did not show significant differences between the groups (P > 0.05); however, statistically significant differences were observed over time (P < 0.0001). Similar histologic features were achieved for both groups. CONCLUSIONS: These results suggest that PEMF stimulation does not improve the bone-healing process around commercially pure dental implants.

Animals↗
PubMed2004

Experimental evidence of a potentially increased thrombo-embolic disease risk by domestic electromagnetic field exposure.

We have used the EaHy926 endothelial cell line, able to secrete both pro and anti-aggregant platelet agents, as a model for thrombo-embolic diseases. We experimentally established, by comparing these two secretions with or without a Faraday cage, that the environmental electromagnetic field significantly increases the thrombo-embolic risks in this endothelial cell line.

6-Ketoprostaglandin F1 alpha↗
PubMed2000

Morphologic responses of osteoblast-like cells in monolayer culture to ELF electromagnetic fields.

Osteoblast-like cells (MC 3T3-E1) were exposed for 24 h, immediately after plating, to a 60 Hz, 0.7 mT rms magnetic flux density, sufficient to induce an electric field of 0.5 mV/m rms, in order to investigate the influence of ELF field exposure on cell morphology. Using phase contrast images of the live cells, computerized image-analysis permitted rapid and objective quantification of cell length, width, area, perimeter, circularity and angular orientation. While the field-exposed cells were consistently smaller than sham treated cells, the morphologic alterations were not significantly different in the exposed cell population when cell orientation was not considered. When analyzed with respect to cell orientation, cells oriented parallel to the induced electric field (orthogonal to the applied magnetic field) demonstrated a significant decrease in cell length and an increase in roundness. These results confirm and extend previous studies on the morphologic adaptation of cells to low level ELF electromagnetic fields. The results suggest that the observed responses most likely depend on the induced electric field, with a field intensity threshold well below 1 mV/m. Further, these results provide important clues to the specific mechanism by which such low level fields may be capable of influencing cell behavior, and help to explain some of the difficulties in obtaining robust responses in in vitro EMF experiments.

3T3 Cells↗