Unknown authors · 2010
Italian researchers exposed rat thyroid cells (FRTL-5) to 900 MHz GSM mobile phone radiation for up to 96 hours and measured key cellular functions. The study found no changes in the cells' ability to produce cAMP or uptake iodine, two critical thyroid functions. This suggests that mobile phone frequencies may not directly interfere with basic thyroid cell biochemistry in laboratory conditions.
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.
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.
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.
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.
Arendash GW et al. · 2010
Researchers studied the effects of long-term EMF exposure at 918 MHz and 0.25 w/kg on both normal mice and transgenic mice bred to develop Alzheimer's-like cognitive impairment. Both cognitive-protective and cognitive-enhancing effects of EMF exposure were discovered for both normal mice and transgenic mice destined to develop Alzheimer's-like cognitive impairment. In Alzheimer's disease mice, long-term EMF exposure reduced brain amyloid-beta deposition through anti-aggregation actions and increased brain temperature during exposure periods. The researchers concluded that EMF exposure may represent a non-invasive, non-pharmacologic therapeutic against Alzheimer's disease, while cautioning against directly extrapolating these mouse findings to humans.
Fragopoulou AF et al. · 2010
Researchers tested the effects of mobile phone radiation on spatial learning and memory in mice using the Morris water maze, a hippocampal-dependent spatial memory task. The mice received a 2 h daily dose of pulsed GSM 900 MHz radiation from a commercially available mobile phone for 4 days at SAR values ranging from 0.41 to 0.98 W/kg. Exposed animals showed a deficit in transferring acquired spatial information across training days, with increased escape latency and distance swam compared to sham-exposed animals. During the memory probe trial, sham-exposed animals showed the expected preference for the target quadrant, while exposed animals showed no preference.
Söderqvist F, Hardell L, Carlberg M, Mild KH · 2010
Researchers proposed that transthyretin (TTR), a protein that sequesters amyloid-beta, might help explain findings related to radiofrequency exposure and Alzheimer's disease. In a provocation study on 41 persons exposed for 30 minutes to an 890-MHz GSM signal at 1.0 Watt/kg to the temporal area of the brain, serum TTR was found to be statistically significantly increased 60 minutes after exposure. In a cross-sectional study on 313 subjects, a statistically significantly positive association was found between serum TTR and time since first use of mobile phones and desktop cordless phones combined (P=0.03).
Maskey D et al. · 2010
Researchers measured calbindin (CB) and calretinin (CR) expression in the hippocampus of mice after exposure to 835 MHz electromagnetic fields at various durations and absorption rates. Exposure conditions included 1 hour per day for 5 days at a specific absorption rate of 1.6 W/kg, 1 hour per day for 5 days at 4.0 W/kg, 5 hours per day for 1 day at 1.6 W/kg, 5 hours per day for 1 day at 4.0 W/kg, and daily exposure for 1 month at 1.6 W/kg. Exposure for 1 month produced almost complete loss of pyramidal cells in the CA1 area. Body weights did not change significantly across the exposure groups.
Maskey D et al. · 2010
Researchers investigated the effect of 835-MHz radiofrequency exposure on rat hippocampus for 3 months using immunohistochemical methods. A decrease in calbindin immunoreactivity was observed in the exposed group, with loss of interneurons and pyramidal cells in the CA1 area and loss of granule cells. An overall increase in GFAP immunoreactivity was observed in the hippocampus of exposed rats, and apoptotic cells were detected in the CA1, CA3 areas and dentate gyrus.
Sonmez OF, Odaci E, Bas O, Kaplan S · 2010
Researchers exposed 16-week-old adult female rats to 900 MHz EMF for 1 hour per day for 28 days and then counted Purkinje cells in the cerebellum using a stereological technique. The total number of Purkinje cells in the exposed group was significantly lower than in both the control group (p < 0.004) and the sham-exposed group (p < 0.002). Body and brain weights did not differ significantly between the exposed and unexposed groups.
Xu S et al. · 2010
Researchers exposed brain neurons to cell phone-frequency radiation (1800 MHz) at levels similar to heavy phone use and found it damaged the DNA inside cellular powerhouses called mitochondria. The radiation increased markers of DNA damage by 24 hours and reduced the neurons' ability to produce energy. Importantly, the antioxidant melatonin completely prevented this damage, suggesting oxidative stress was the underlying cause.
Carrubba S, Frilot C 2nd, Chesson AL Jr, Marino AA · 2010
Researchers recorded EEGs from six standard locations in 20 volunteers to detect brain potentials triggered by a pulse of the type produced by mobile phones. Evoked potentials having the expected latency were found in 90% of the volunteers, as assessed using a nonlinear method of EEG analysis. Evoked potentials were not detected when the EEG was analyzed using time averaging. The possibility of systematic error was excluded by sham-exposure analyses.
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.
Kumar S, Jain S, Behari J, Avelev VD, Mathur R. · 2010
Researchers studied the effect of magnetic field exposure on food intake, water intake, and body weight in rats with complete spinal cord injury. Exposure ran at 50 Hz and 17.9 T for 2 hours per day over 8 weeks in rats with complete spinal cord transection at the T13 level. The results suggest a significant beneficial effect of chronic exposure to magnetic field of paraplegic rats.
Szemerszky R, Zelena D, Barna I, Bárdos G. · 2010
Researchers exposed adult male Sprague-Dawley rats to 50 Hz electromagnetic fields at 0.5 mT, either for 5 days at 8 hours daily or for 4 to 6 weeks at 24 hours daily. Neither exposure duration produced the body changes associated with chronic stress, such as body weight reduction, thymus involution, or adrenal gland hypertrophy. After long-term exposure, rats showed elevated proopiomelanocortin and depressive-like behavior, and blood glucose was also higher. The researchers noted that the exposure intensity used was much higher than typical human exposure.
Frahm J, Mattsson MO, Simkó M. · 2010
Researchers exposed mouse macrophages to a 50 Hz, 1.0 mT magnetic field and measured changes in reactive oxygen species production and protein expression. Short-term exposures of two hours or less caused slight and transient decreases in several proteins, including clathrin, adaptin, PI3-kinase, protein kinase B, and PP2A, while longer exposures had no effect on these proteins. The stress proteins Hsp70 and Hsp110 showed increased levels at certain time points but not generally.
Garip AI, Akan Z. · 2010
Researchers investigated the effect of ELF-EMF on apoptosis in K562 human leukemia cells, with and without oxidative stress, and examined links to heat-shock protein 70 levels. ELF-EMF at 1 mT and 50 Hz was applied for 3 hours, with one group of cells treated with H2O2 to induce oxidative stress and another left untreated. In cells not exposed to oxidative stress, ELF-EMF caused a decrease in the number of apoptotic cells and a slight increase in viability. In cells treated with H2O2, ELF-EMF increased the number of apoptotic cells, and hsp70 and reactive oxygen species levels were also increased.
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.
Mannerling AC, Simkó M, Mild KH, Mattsson MO · 2010
Researchers exposed human K562 leukemia cells to a 50-Hz sine-wave magnetic field for 1 hour at flux densities ranging from 0.025 to 0.10 mT, measuring proliferation, cell cycle distribution, superoxide radical anion levels, and HSP70 protein levels. Both vertical and horizontal exposures caused significantly and transiently increased HSP70 levels of more than twofold at several flux densities, compared to sham controls and also compared to a heat-treatment positive control. Superoxide radical anion levels increased by 30–40%, and adding free radical scavengers melatonin or 1,10-phenantroline inhibited the magnetic-field-induced increase in HSP70. Cell cycle kinetics and proliferation were not affected by exposure at 0.10 mT for 1 hour.
Morabito C et al. · 2010
Researchers used C2C12 cells as an in vitro model of the skeletal muscle phenotype to study the effects of short-term exposure to extremely low frequency electromagnetic fields on muscle cell differentiation and function. ELF-EMFs induced reactive oxygen species production in myoblasts and myotubes with a concomitant decrease in mitochondrial membrane potential. The cellular detoxification system was activated, with increases in catalase and glutathione peroxidase activities. ELF-EMFs also altered intracellular calcium homeostasis, increasing the spontaneous activity of myotubes and enhancing cellular reactivity to a depolarizing agent or an agonist of intracellular store calcium channels.
Achudume A, Onibere B, Aina F, Tchokossa P · 2010
Researchers exposed male Wistar rats to radio frequency radiation at 1800 MHz with a specific absorption rate of 0.95 to 3.9 W/kg for 40 or 60 days continuously. At 40 days, electromagnetic radiation failed to induce any significant alterations. At 60 days of exposure, various attributes evaluated decreased, including decreases in NADPH and ascorbate-linked lipid peroxidation along with diminution in enzymatic antioxidative defense systems and decreased glucose residue.
Cuccurazzu B et al. · 2010
Italian researchers exposed mice to 50 Hz electromagnetic fields (European power line frequency) for up to seven hours daily over one week. This significantly increased new brain cell growth in the hippocampus, improving long-term memory formation and suggesting potential therapeutic applications for brain regenerative medicine.
Szemerszky R, Zelena D, Barna I, Bárdos G. · 2010
Researchers exposed rats to 50 Hz electromagnetic fields (household electrical frequency) for weeks and found increased blood sugar, stress hormones, and depression-like behavior compared to short-term exposure. This suggests chronic EMF exposure may act as a mild stressor affecting mood and metabolism.
Volkow ND et al. · 2010
Researchers measured brain glucose metabolism in fifteen healthy subjects inside a 4 T magnet, comparing conditions with and without echo-planar imaging (EPI) gradient pulses. Relative metabolism was lower in areas at the poles of the brain when the EPI pulses were on compared to when they were off. The size of the metabolic decreases was significantly correlated with the estimated strength of the electric field (r = 0.68, p < 0.0001), such that a stronger field was associated with larger decreases. No differences were detected between the ON and OFF conditions for mood ratings or for absolute whole-brain metabolism.
