Chavdoula ED, Panagopoulos DJ, Margaritis LH. · 2010
Researchers exposed Drosophila melanogaster to GSM-900MHz radiation for 6 minutes daily to compare continuous and intermittent exposure effects on reproductive capacity and apoptotic cell death. Previous work showed 6-minute continuous daily exposure for five days greatly reduced reproductive capacity, measured by F1 pupae count, and this decrease was non-thermal and linked to increased DNA fragmentation in egg chamber cells. The current experiments found intermittent exposure also reduced reproductive capacity and disrupted the actin-cytoskeleton network of egg chambers, with the effect also due to DNA fragmentation. Intermittent exposures with 10-minute intervals were almost as effective as continuous exposure, while longer intervals allowed the flies to partly recover.
Lakshmi NK, Tiwari R, Bhargava SC, Ahuja YR. · 2010
Overall DNA damage and micronuclei incidence did not differ significantly between exposed and control groups. Subgroups were analyzed by total duration of use in years and daily frequency in minutes. Long-term users of more than 10 years showed higher DNA damage and increased micronuclei frequency. DNA damage was measured with the alkaline comet assay and micronuclei with the cytochalasin blocked micronucleus assay.
Franzellitti S et al. · 2010
Researchers exposed human trophoblast HTR-8/SVneo cells to 1.8 GHz continuous wave and GSM signals for 4, 16, or 24 hours. The GSM-Talk signal used an intermittent pattern of 5 minutes on and 10 minutes off. The alkaline comet assay measured primary DNA damage and strand breaks from incomplete repair. Amplitude-modulated GSM-217 Hz and GSM-Talk signals significantly increased comet parameters after 16 and 24 hours, while continuous wave did not. DNA damage recovered within 2 hours after exposure ended, returning to sham-exposed levels.
Tomruk A, Guler G, Dincel AS. · 2010
Researchers exposed nonpregnant and pregnant New Zealand White rabbits to whole-body 1800 MHz GSM-like RF radiation for 15 minutes per day over one week. Liver 8-OHdG levels did not differ between exposed and control rabbits in either the adult or newborn groups. However, MDA and FOX levels were significantly higher in exposed adult rabbits, and FOX was also elevated in newborns of exposed mothers.
Wang Z, Che PL, Du J, Ha B, Yarema KJ. · 2010
Researchers investigated static magnetic fields by focusing on the adenosine A2A receptor in PC12 rat adrenal pheochromocytoma cells that display metabolic features of Parkinson's disease. Static magnetic fields reproduced several responses elicited by ZM241385 and counteracted several PD-relevant endpoints exacerbated by CGS21680 in a manner similar to ZM241385.
Tillmann T et al. · 2010
Researchers exposed mice to UMTS fields at 0, 4.8, and 48 W/m(2) for up to 24 months starting from embryo-fetal exposure, with the 4.8 W/m(2) group also receiving prenatal ethylnitrosourea at 40 mg ENU/kg body weight. The high-level UMTS exposure (48 W/m(2)) showed tumour incidences comparable to sham and cage control groups. Mice given ethylnitrosourea and exposed to 4.8 W/m(2) UMTS had higher lung tumour rates and more lung carcinomas than ethylnitrosourea-only controls. Lung carcinoma multiplicity increased and the number of metastasising lung tumours doubled in the combined exposure group.
Zhijian C et al. · 2010
Researchers used a comet assay to study whether 1.8-GHz radiofrequency radiation (RFR, SAR of 2 W/kg) could influence DNA repair in human B-cell lymphoblastoid cells exposed to doxorubicin (DOX). RFR alone did not directly induce DNA damage in the cells. A specific combined-exposure pattern could obviously influence DNA repair at 6 h and 12 h after exposure to DOX for four DOX doses.
Potenza L et al. · 2010
Researchers exposed human umbilical vein endothelial cells (HUVECs) to a 300 mT static magnetic field for 4, 24, 48, and 72 hours. After 4 hours of exposure, the static field induced damage at the nuclear and mitochondrial levels, reduced mitochondrial content, and increased reactive oxygen species. Twenty-four hours of exposure increased mitochondrial DNA content as well as expression of a gene related to mitochondrial biogenesis. No significant differences between exposed and sham cultures were found after 48 and 72 hours, and cell viability did not show a statistically significant change overall.
Lee HM et al. · 2010
Researchers cultured human intervertebral disc (IVD) cells in alginate beads and exposed them to an electromagnetic field at 1.8 millitesla magnetic flux density and 60 Hz. Cellular proliferation was observed in the EMF group (p < 0.05), and no cytotoxicity was found. There was no significant change in the expression of aggrecan, type I, and type II collagen mRNA in the EMF group compared to the control group. DNA synthesis was partially mediated by nitric oxide and prostaglandin E2.
Cuccurazzu B et al. · 2010
The exposure significantly enhanced neurogenesis in the dentate gyrus, with increased numbers of cells labeled for markers of new and developing neurons. Roughly half of the newly generated neurons survived 30 days after stimulation and became mature neurons integrated into the granule cell layer. The new mature neurons were associated with increased long-term potentiation, indicating an influence on hippocampal synaptic plasticity.
Xu S et al. · 2010
Researchers exposed primary cultured cortical neurons to pulsed radiofrequency electromagnetic fields at 1800 MHz modulated by 217 Hz at an average specific absorption rate of 2 W/kg. At 24 hours after exposure, researchers found a significant increase in levels of 8-hydroxyguanine, a common biomarker of DNA oxidative damage, in the mitochondria of neurons. The copy number of mitochondrial DNA and the levels of mitochondrial RNA transcripts showed an obvious reduction after RF exposure. Each of these mitochondrial DNA disturbances could be reversed by pretreatment with melatonin.
Kumar S, Kesari KK, Behari J. · 2010
Wistar rats were exposed to microwaves for 2 hours a day for 45 days at either 10 GHz or 50 GHz, and blood cells and serum were then analyzed. The exposed rats showed micronuclei formation and a significant increase in ROS production, along with significant changes in glutathione peroxidase, superoxide dismutase, and catalase levels. The researchers concluded that microwave exposure may be effective at the genetic level and suggested this may indicate tumor promotion through overproduction of reactive oxygen species.
Kesari KK, Behari J, Kumar S. · 2010
Researchers exposed male Wistar rats to 2.45 GHz microwave radiation for 2 hours a day for 35 days at a power density of 0.34 mW/cm2. The whole brain tissue was dissected and used for study of double strand DNA breaks by micro gel electrophoresis and comet assay. Exposed brain cells showed a significant increase in comet head, tail length, and tail movement. The study concluded that chronic exposure to these radiations may cause significant damage to brain, which may be an indication of possible tumour promotion.
Guler G, Tomruk A, Ozgur E, Seyhan N. · 2010
Researchers investigated oxidative DNA damage and lipid peroxidation levels in the brain tissue of pregnant and non-pregnant New Zealand White rabbits and their newborns exposed to radiofrequency radiation. The rabbits were exposed to radiofrequency radiation at 1800 MHz GSM at 14 V/m for 15 minutes per day over 7 days. MDA and 8-OHdG levels in exposed pregnant and non-pregnant rabbits were significantly increased compared to controls, but no difference was found in the newborns.
Campisi A et al. · 2010
Researchers exposed primary rat neocortical astroglial cell cultures to electromagnetic fields in the microwave range, either as continuous waves or amplitude-modulated at 50 Hz, for 5, 10, or 20 minutes. A significant increase in ROS levels and DNA fragmentation was found only after exposure of the astrocytes to modulated EMF for 20 min. Cell viability was not affected, and the irradiation conditions allowed the exclusion of any possible thermal effect.
Unknown authors · 2009
Researchers conducted a cytogenetic monitoring study on 55 workers from transformer and distribution line stations in Bursa, Turkey, and 17 controls. Chromosomal aberration and micronucleus frequencies were significantly higher in exposed workers than in controls. Chromosomal aberration frequency increased significantly with years of exposure. Smoking did not significantly affect chromosomal aberration or micronucleus levels in either group.
Unknown authors · 2009
Application of an EF following irradiation greatly increases cell death. The result for the number of nuclei with gamma-H2AX foci in MRC5 cells indicates that an EF interferes mostly in the DNA repair mechanisms.
Unknown authors · 2009
Researchers exposed 10 male and 10 female healthy volunteers to a 200 microT, 60 Hz magnetic field for 4 hours, with five male and five female volunteers as sham controls. There was no evidence of increased DNA damage or increased micronuclei in the magnetic field exposed group. A 1.5 Gy gamma-irradiation positive control caused a significant increase in both DNA damage and micronuclei.
Shckorbatov YG et al. · 2009
Researchers exposed isolated human buccal epithelium cells to microwaves of frequency 35 GHz at a surface power density of 30 microW/cm(2). Chromatin state was examined by light and electron microscopy, and membrane integrity was assessed with vital indigo carmine staining. Microwave exposure induced chromatin condensation, and the extent of condensation depended on wave polarization. Linearly polarized waves also caused cell membrane damage, shown by increased vital dye staining.
Garaj-Vrhovac V, Gajski G, Trosić I, Pavicić I · 2009
The animals were irradiated for 1h a day for 2 weeks at a field power density of 2.4W/m(2) and a whole-body average specific absorption rate (SAR) of 0.6W/kg. Both the standard comet assay and the Fpg-modified comet assay detected increased DNA damage in blood leukocytes of the exposed rats. The significant increase in Fpg-detected DNA damage suggests oxidative stress is likely responsible, while DNA damage detected by the standard comet assay indicates other mechanisms may also be involved.
Unknown authors · 2009
Extremely low frequency magnetic fields in cell culture incubators have been measured. Values of the order of tens of μT were found, in sharp contrast to normal environmental levels of 0.05–0.1 μT. Numerous biological effects have been reported at these field levels, such as changes in gene expression, blocked cell differentiation, inhibition of the effect of tamoxifen, and effects on chick embryo development.
Unknown authors · 2009
The purpose of the work was to review and compare recent findings on the induction of DNA strand breaks by magnetic field exposure. The review found 29 studies, with 50% showing an effect of magnetic fields and 50% showing no DNA strand breaks. When considering only genotoxic studies, 37.5% found induction of DNA strand breaks, while 69.2% of epigenetic studies found induction. The authors suggest magnetic fields could act as a co-inductor of DNA damage.
Unknown authors · 2009
Researchers conducted a cytogenetic monitoring study on 55 workers at transformer and distribution line stations and 17 controls to assess genotoxic risk from ELF-EMF exposure. Chromosomal aberration and micronucleus frequencies were significantly higher in exposed workers than in controls. Chromosomal aberration frequency increased with years of exposure, while smoking did not significantly affect either marker.
Unknown authors · 2009
A meta-analysis was conducted to obtain a quantitative estimate of the extent of genetic damage in mammalian somatic cells exposed to extremely low frequency electro-magnetic fields and to compare with that in unexposed control cells. Three specific variables related to ELF-EMF exposure characteristics were examined: frequency (Hz), flux density (mT), and occupationally exposed individuals. The difference between ELF-EMF-exposed and control cells as well as the effect size due to ELF-EMF exposure were biologically small although statistically significant with very few exceptions. Considerable evidence for publication bias was found in the meta-analysis.
Unknown authors · 2009
The authors state that a major concern of EMF exposure is cancer induction because most cancers start with damage to a cell's genome. The review describes the comet assay, which detects single-strand breaks, double-strand breaks, and crosslinks in DNA. It also reviews studies on chromosomal conformational changes and micronucleus formation after EMF exposure. The review discusses lessons learned from the authors' own work in this area.
