Pilla AA · 2012
Researchers tested how a non-thermal pulse-modulated RF signal affected nitric oxide release in dopaminergic MN9D neuronal cells challenged with lipopolysaccharides and in human fibroblast cultures challenged with low serum. In dopaminergic MN9D cultures, the signal produced an immediate nearly three-fold increase in nitric oxide, measured in real-time using a nitric oxide selective membrane electrode. In human fibroblast cultures challenged with low serum and exposed for 15 minutes to the same signal, nitric oxide increased nearly two-fold, and this increase could be blocked by the calmodulin antagonist W-7.
Patruno A et al. · 2012
Researchers exposed THP-1 cells to a 50 Hz, 1 mT electromagnetic field for 24 hours, with or without LPS, to study effects on matrix metalloproteinases (MMPs) and their inhibitor TIMP-1. Exposure was associated with a reduction of antioxidant enzyme activity and an enhancement of nitrogen intermediates involving the iNOS pathway. The researchers analyzed the role of nitration of TIMP-1 in increasing the activity of MMPs in EMF-exposed cells, and molecular modeling identified at least two protein sites, Y120 and Y38 and/or Y72, as plausible targets. The results may suggest a pathway connecting an imbalance of MMPs and their cognate inhibitor TIMP-1.
Pakhomova ON et al. · 2012
Researchers assessed reactive oxygen species (ROS) production in cultured cells and media exposed to 300-ns pulsed electric fields at 1 to 13 kV/cm. In cell-free media, the pulsed electric field facilitated conversion of H2DCF into the fluorescent marker DCF, an effect reduced by catalase but not by mannitol or superoxide dismutase, and not related to heating. The researchers concluded that bioeffects of nanosecond pulsed electric fields are not limited to electropermeabilization, and that concurrent ROS formation may lead to cell stimulation and/or oxidative cell damage.
Jouni FJ, Abdolmaleki P, Ghanati F. · 2012
Researchers studied whether a static magnetic field affects oxidative stress in Vicia faba plants grown in soil from a high background natural radioactivity area of Iran. Plants were continuously exposed to a static magnetic field of 15 mT for 8 days, each 8 hours per day. Antioxidant enzyme activity and flavonoid content were lower in plants from both high and low natural radioactivity soils compared to the control. The results suggest that static magnetic field exposure causes accumulation of reactive oxygen species, and that natural radioactivity of soil exaggerates oxidative stress.
Bułdak RJ et al. · 2012
Researchers assessed how cisplatin and an extremely low frequency electromagnetic field (ELF-EMF) affected antioxidant enzyme activity, lipid peroxidation, DNA damage, and reactive oxygen species (ROS) production in AT478 carcinoma cells. Cells were cultured with cisplatin for 24 and 72 hours and irradiated with 50 Hz/1 mT ELF-EMF for 16 minutes using a solenoid. When ELF-EMF was combined with cisplatin, ROS levels, antioxidant enzyme activity, and DNA damage all decreased compared to cisplatin alone, but ELF-EMF by itself increased DNA damage relative to control cells.
Tasset I et al. · 2012
Researchers investigated the neuroprotective effects of extremely low-frequency electromagnetic fields (ELFEF) in a rat model of Huntington's disease induced by 3-nitropropionic acid (3NP). Rats were given 3NP over four consecutive days at 20 mg/kg body weight, and ELFEF at 60 Hz and 0.7 mT was applied over 21 days, starting after the last injection. Rats treated with 3NP showed significant differences in behavior, neurotrophic factor levels, oxidative stress biomarkers, and reduced neuronal density compared with neuronal controls. ELFEF improved neurological scores, enhanced neurotrophic factor levels, and reduced both oxidative damage and neuronal loss in 3NP-treated rats.
Shafiei SA et al. · 2012
Researchers exposed different parts of the brain to extremely low-frequency magnetic fields locally and investigated EEG power spectrum changes at the frequency of stimulation. EEG relative power spectrum was evaluated at 3, 5, 10, 17, and 45 Hz frequencies at T4, T3, F3, Cz, and F4 points, when those points were exposed to magnetic fields at similar frequencies and 100 μT intensity. EEG power did not change significantly at the frequency of stimulation, but significant changes were observed in different EEG bands.
Sakhnini L, Al Ali H, Al Qassab N, Al Arab E, Kamal A. · 2012
Researchers investigated the possible effect of ELF-EMFs on motor performance in prenatal and neonatal exposed mice. Motor performance was evaluated using rotarod experiments after 5 days of subacute exposure. Prenatal exposed groups showed a pronounced deficit in learning abilities, but no pronounced effect was observed for the neonatal exposed group.
Rageh MM, El-Gebaly RH, El-Bialy NS. · 2012
Researchers exposed newborn rats continuously to a 50 Hz, 0.5 mT extremely low-frequency magnetic field for 30 days, starting when the rats were 10 days old. DNA damage in brain cells, measured by comet assay, was significantly higher in the exposed group. Exposure was associated with a significant four-fold increase in micronucleus induction and about a three-fold increase in mitotic index in bone marrow cells. Exposed rats also showed significantly higher levels of MDA and SOD, while ELF-MF failed to alter the activity of GSH.
Rauš S, Selaković V, Radenović L, Prolić Z, Janać B. · 2012
Researchers studied how an extremely low frequency magnetic field affects motor behaviour in 3-month-old Mongolian gerbils that had undergone global cerebral ischemia. After a 10-minute blockage of both common carotid arteries, gerbils were continuously exposed to ELF-MF at 50 Hz and 0.5 mT for 7 days, and their behaviour was monitored on days 1, 2, 4, 7, and 14 after reperfusion. Ischemia alone caused significant increases in locomotion, stereotypy, and rotations, along with decreased immobility, up to day 4 after reperfusion compared to control gerbils. ELF-MF exposure inhibited ischemia-induced motor hyperactivity throughout the observation period, though significantly only in the first 2 days after reperfusion.
Legros A et al. · 2012
Researchers investigated the effects of a 60 Hz, 1,800 μT magnetic field on neurophysiological and neuromotor measures in humans, including EEG, standing balance, voluntary motor function, and physiological tremor. Results suggested a reduction of human standing balance and an increase of physiological tremor amplitude in the frequency range associated with central nervous system contribution, while no exposure effect appeared on EEG or voluntary motor control. The researchers concluded that 1 h of 60 Hz, 1,800 μT magnetic field exposure may modulate human involuntary motor control without being detected in cortical electrical activity.
Korpinar MA, Kalkan MT, Tuncel H. · 2012
Anxiety and stress-related behavioral changes were investigated by elevated plus-maze and hole-board systems. In the elevated plus-maze, exposed rats spent proportionally less time on open arms than control rats (0.12±0.08 versus 0.34±0.18, p <0.01), while hole-board results showed no statistically significant differences between the two groups.
Janać B et al. · 2012
Researchers investigated how extremely low frequency magnetic fields affected locomotion, stereotypy, and immobility in 3- and 10-month-old male Mongolian gerbils. The animals were continuously exposed to ELF-MF for seven days. In the younger gerbils, all three field strengths increased locomotion and stereotypy and decreased immobility. In the older gerbils, the lowest field strength decreased motor behavior, the middle strength produced a slight increase, and the highest strength produced a pronounced stimulation.
Fournier NM, Mach QH, Whissell PD, Persinger MA. · 2012
Pregnant Wistar rats were continuously exposed to one of four intensities of a complex magnetic field throughout gestation. Exposure to weaker or stronger intensities of the same field pattern did not interfere with hippocampal development or fear behavior.
Das S, Kumar S, Jain S, Avelev VD, Mathur R. · 2012
Researchers studied the effect of a 50 Hz, 17.96 μT magnetic field on rats after a hemisection injury of the T13 spinal cord, measuring locomotor function, motor responses to noxious stimuli, and neuronal excitability. Rats were divided into a sham-exposed group and a group exposed to the magnetic field for 2 hours per day for 6 weeks. The magnetic-field-exposed group showed a statistically significant improvement in BBB score over the sham control group, and bladder control was dramatically restored earlier than in the sham group. The researchers suggested that this magnetic field exposure promotes recovery of sensori-motor behavior including locomotion and bladder control in spinal-cord-injured rats.
Cui Y, Ge Z, Rizak JD, Zhai C, Zhou Z, Gong S, Che Y. · 2012
Researchers examined the effects of extremely low frequency magnetic field (ELF-MF) exposure on learning in mice using two water maze tasks. ELF-MF exposure at 1 mT, 50 Hz was associated with oxidative stress in the hippocampus and striatum, and impaired both spatial learning and habit learning. The study provides evidence for an association between impaired learning and oxidative stress in the hippocampus and striatum induced by ELF-MF exposure.
Cho SI et al. · 2012
Researchers designed the study to confirm that extremely low-frequency magnetic fields affect neuronal NOS in several brain regions and to investigate the correlation between nitric oxide and nNOS activation. Exposure of rats to a 2 mT, 60 Hz ELF-MF for 5 days resulted in increases of nitric oxide levels in parallel with cGMP elevations in the cerebral cortex, striatum, and hippocampus. The numbers of nNOS-immunoreactive neurons were significantly increased in those cerebral areas in ELF-MF-exposed rats. Staining and electron microscopy showed no significant differences in the morphology or number of neurons in the cerebral cortex, striatum, and hippocampus.
Akpinar D, Ozturk N, Ozen S, Agar A, Yargicoglu P. · 2012
Researchers divided thirty female Wistar rats, aged 3 months, into three equal groups: a control group, a group exposed to electric fields at 12 kV/m, and a group exposed at 18 kV/m, with exposure applied for 14 days at 1 hour per day. Brain and retina oxidative stress markers were significantly increased in both exposed groups compared to the control group. Total antioxidant status levels were significantly decreased in both brain and retina in the exposed groups compared to the control group. All visual evoked potential components were significantly prolonged in rats exposed to electric fields compared to the control group.
Yang XS, He GL, Hao YT, Xiao Y, Chen CH, Zhang GB, Yu ZP. · 2012
Researchers exposed adult male Sprague-Dawley rats to a 2.45 GHz electromagnetic field at a specific absorption rate of 6 W/kg, or to sham conditions, then examined gene and protein expression in the hippocampus. Of 2048 candidate genes examined, 23 were upregulated and 18 were downregulated. Two heat shock proteins, HSP27 and HSP70, stood out because their expression levels were increased in the rat hippocampus. The researchers concluded that their data provide direct evidence that exposure to electromagnetic fields elicits a stress response in the rat hippocampus.
Spichtig S, Scholkmann F, Chin L, Lehmann H, Wolf M · 2012
Researchers used near-infrared spectroscopy to assess potential effects of UMTS electromagnetic fields on blood circulation in the auditory region of the human head. Three different exposures (sham, 0.18 W/kg, and 1.8 W/kg) were applied in a controlled, randomized, crossover, and double-blind paradigm on 16 healthy volunteers. During exposure to 0.18 W/kg, a significant short-term increase in oxyhaemoglobin and total haemoglobin was found, described as small compared to a functional brain activation. Medium-term heart rate was significantly higher (+1.84 bpm) at 1.8 W/kg than for sham exposure, while the other parameters showed no significant effects.
Sokolovic D et al. · 2012
Researchers exposed Wistar rats to microwave radiation for 4 hours per day and tested whether melatonin could counter any resulting changes in body mass or behaviour. A significant body mass reduction was noted in animals exposed to MW radiation when compared to controls after 20, 40 and 60 days (p<0.001). Exposed animals showed anxiety-related behaviour described as agitation and irritability after 10 days of exposure, and these changes became less noticeable after the radiation source was removed. Melatonin pretreatment significantly increased body weight in irradiated rats compared to irradiated rats without melatonin after 20 days (p<0.05), and melatonin administration caused a decrease in stress-induced behaviour.
Schmid MR et al. · 2012
Twenty-five young healthy men took part in a randomized double-blind crossover design, exposed at weekly intervals to different conditions for 30 minutes before sleep. The conditions were a 2-Hz pulse-modulated radio frequency field, a 2-Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Delta and theta activity during non-rapid eye movement sleep, and alpha and delta activity during rapid eye movement sleep, were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed.
Schmid MR et al. · 2012
Thirty young healthy men were exposed, at weekly intervals, for 30 minutes directly before an 8-hour sleep period to a 900-MHz RF EMF pulse-modulated at 14 Hz, at 217 Hz, or to a sham control. EEG power in the spindle frequency range was increased during non-rapid eye movement sleep after the 14-Hz pulse-modulated condition, while a similar but non-significant increase was also observed after the 217-Hz condition. No clear exposure-related effects on cognitive performance were seen, and the exposure-induced effect showed considerable individual variability.
Nittby H et al. · 2012
Researchers exposed 29 land snails of the strain Helix pomatia to GSM electromagnetic fields at 1900 MHz at 48 mW/kg for 1 hour each, while 29 snails served as sham controls. Before and after exposure, snails were placed on a hot plate and the time until they retracted was measured by two blinded observers. GSM-exposed snails were less sensitive to thermal pain compared to sham controls, indicating a significant analgesia (Mann-Whitney p < 0.001).
Nazıroğlu M et al. · 2012
Researchers divided rats into four groups: a cage control, a sham control, a group exposed to 2.45 GHz electromagnetic radiation, and a group exposed to the same radiation while also receiving melatonin. The radiation-exposed groups received that exposure for 60 minutes per day for 30 days, after which brain cortex and dorsal root ganglion samples and EEG recordings were collected. Lipid peroxidation, cell viability, and cytosolic calcium values in dorsal root ganglion neurons were higher in the radiation-only group than in the control groups. The melatonin-plus-radiation group showed lower EEG spike numbers and higher brain cortex vitamin E concentration compared with the radiation-only group.
