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 investigated whether ELF-MF exposure could increase DnaK and GroEL protein levels in E. coli cells that lack a classic heat shock response. The cells showed enhanced DnaK and GroEL protein levels after 30 or 90 minutes of sinusoidal 50 Hz, 1 mT ELF-MF exposure. The result suggests the HSP induction pathway from ELF-MF exposure may differ from the heat shock pathway.
Unknown authors · 2009
Unknown authors · 2009
Researchers exposed Caco 2 cells to 50 Hz, 1 mT electromagnetic fields for 24–72 hours to study protein oxidation and 20S proteasome functionality. The exposure caused a time-dependent increase in cell growth and protein oxidation, more pronounced with TPA, but did not affect cell viability. The fields also globally activated the 20S proteasome catalytic components, especially at 72 hours and with TPA, and the antioxidant EGCG reversed these pro-oxidant effects, indicating the activation was due to increased free radicals.
Unknown authors · 2009
Researchers exposed human peripheral blood mononuclear cells from 20 volunteers to extremely low frequency (ELF) and Therapeutic Application of Musically Modulated Electromagnetic Fields (TAMMEFs) in vitro. ELF fields were 100 Hz, while TAMMEFs had variable frequencies, intensities, and wave shapes. Adenylate kinase activity increased after ELF exposure and decreased slightly after TAMMEF exposure, but ecto-5′-nucleotidase, adenosine deaminase, and adenosine kinase activities were unchanged.
Güler G, Türközer Z, Ozgur E, Seyhan N. · 2009
Researchers exposed subjects to a 50 Hz, 12 kV/m electric field for 7 days at 8 hours per day and measured pulmonary levels of heme oxygenase-1, protein carbonyl content, malondialdehyde, nitric oxide, and hydroxyproline. Protein carbonyl content increased significantly with electric field exposure compared to controls, while the other four markers showed no significant change. Adding the antioxidants NAC or EGCG during exposure did not produce significant changes in any of the measured parameters compared to electric field exposure alone.
Güler G, Türközer Z, Ozgur E, Tomruk A, Seyhan N, Karasu C · 2009
Researchers exposed guinea pigs to a 50 Hz, 12 kV/m electric field for 7 days, 8 hours per day, and measured protein carbonyl content (PCO), advanced oxidation protein products (AOPP) in liver, and 3-nitrotyrosine (3-NT) in plasma. They also assessed hepatic hydroxyproline levels to study protein synthesis. Exposure to the electric field did not significantly change PCO, AOPP, or 3-NT levels compared to controls. However, liver hydroxyproline was significantly reduced in the exposed group. N-acetyl-L-cysteine (NAC) administration significantly altered PCO, hydroxyproline, and 3-NT levels.
Lu L, Xu H, Wang X, Guo G. · 2009
Researchers exposed Sprague-Dawley rats to electromagnetic pulses and assessed blood-retinal barrier permeability at 2 and 24 hours. Exposure increased barrier permeability and decreased occludin expression most at 24 hours. The permeability increase correlated with higher nitric oxide formation and nitric oxide synthase activity. A nitric oxide synthase inhibitor blocked the barrier breakdown and prevented the changes in nitric oxide, synthase activity, and occludin.
Cao Y, Zhang W, Lu MX, Xu Q, Meng QQ, Nie JH, Tong J. · 2009
In this study, exposure to 900-MHz EMF expanded γ-ray damage to SHG44 cells. Preexposure EMF enhanced the decrease in cell proliferation induced by γ-ray irradiation and the rate of apoptosis. The combination of EMF and γ-ray exposure resulted in a synergistic effect by triggering stress response, which increased reactive oxygen species, but the expression of hsp70 at both mRNA and protein levels remained unaltered.
Mailankot M et al. · 2009
Researchers exposed male albino Wistar rats to RF-EMR from an active GSM mobile phone for one hour daily over 28 days. Exposed rats had significantly reduced sperm motility but no change in total sperm count. RF-EMR exposure also increased lipid peroxidation and decreased glutathione levels in the testis and epididymis. Facial temperature did not change significantly during exposure.
Hässig M, Jud F, Naegeli H, Kupper J, Spiess BM. · 2009
Researchers conducted a cohort study tracking the geographical location of each dam and calf from conception through the fetal period to slaughter, with particular emphasis on the first trimester of gestation (organogenesis). Antioxidant activities of superoxide dismutase, catalase, and glutathione peroxidase were measured in aqueous humor to evaluate redox status. Among 253 calves, 79 (32%) had nuclear cataract and 9 (3.6%) had severe nuclear cataract. Oxidative stress was increased in eyes with cataract, with an odds ratio of 0.80 per kilometer distance from the nearest base station and a 95% confidence interval of 0.62,0.93, and the authors state that it has not been shown that antennas actually affected stress.
Balci M, Namuslu M, Devrim E, Durak I · 2009
Four groups of ten Wistar rats each were studied for three weeks. Rats in the computer and computer plus vitamin C groups were exposed to computer monitors, and vitamin C was given orally at 250 mg/kg/day. In corneal tissue, monitor exposure increased malondialdehyde levels and catalase activity, while vitamin C further raised malondialdehyde, superoxide dismutase, and glutathione peroxidase activities and lowered catalase activity. In lens tissue, monitor exposure raised malondialdehyde and glutathione peroxidase activities and increased superoxide dismutase, while vitamin C increased superoxide dismutase and decreased catalase activity.
Agarwal A et al. · 2009
After liquefaction, neat semen samples were divided into two aliquots, with one exposed to cellular phone radiation in talk mode for 1 hour and the other serving as an unexposed control under identical conditions. Exposed samples showed a significant decrease in sperm motility and viability, an increase in ROS level, and a decrease in ROS-TAC score. Levels of total antioxidant capacity and DNA damage showed no significant differences between exposed and unexposed samples.
Xu Q, Tong J, Jin ZD, Lu MX, DU HB, Cao Y. · 2009
Researchers randomly assigned 96 healthy Kunming mice to four groups: normal control, microwave (120 microW/cm(2), 900 MHz), gamma-ray irradiation (5 Gy), and combined microwave plus gamma-ray (120 microW/cm(2) + 5 Gy). The microwave and combined groups were exposed to 120 microW/cm(2) microwave for 1 h/d for 14 days before the gamma-ray and combined groups received 5 Gy (60)Co gamma-ray irradiation on the 15th day. Bone marrow pathology in the combined exposure group was milder and recovered faster than in the gamma-ray only group. Splenic cell apoptosis was significantly lower in the combined group on days 6 and 9 after irradiation (23.02% +/- 15.18% and 25.37% +/- 11.62%). Serum superoxide dismutase increased and lipid peroxide decreased significantly in the combined group (P < 0.05).
Brescia F et al. · 2009
Researchers measured reactive oxygen species (ROS) production in human lymphoblastoid cells exposed to a 1950 MHz UMTS signal at Specific Absorption Rates of 0.5 and 2.0 W/kg. Exposures ranged from short durations of 5 to 60 minutes up to 24 hours, and the study also tested RF radiation given before or at the same time as ferrous ions. RF exposure did not increase ROS formation or affect cell viability, and combining RF with ferrous ions did not produce more ROS than ferrous ions alone.
Amara S et al. · 2009
Researchers exposed male rats to a static magnetic field at 128 mT for one hour per day over 30 consecutive days and then measured antioxidant enzyme activity, malondialdehyde concentration, and DNA oxidation in the brain. In the frontal cortex, exposure decreased glutathione peroxidase activity by 39%, CuZn superoxide dismutase activity by 35%, and catalase activity by 59%. In the hippocampus, exposure decreased CuZn-SOD activity by 51% and Mn-SOD activity by 13%, and increased malondialdehyde concentration by 32%. DNA oxidation was not detected, and the researchers suggested that an increase in metallothioneins in the frontal cortex may have protected DNA from oxidative damage.
Sharma VP, Singh HP, Kohli RK, Batish DR. · 2009
Researchers exposed mung bean (Vigna radiata) seeds to cell phone EMF radiation at a power density of 8.55 microW cm(-2) in the 900 MHz band for durations of 1/2, 1, 2, and 4 hours. Cell phone EMF radiation significantly inhibited germination at exposures of 2 hours or more, and inhibited radicle and plumule growth at 1 hour or more, in a time-dependent manner. The radiation enhanced MDA content, increased hydrogen peroxide accumulation, and raised root oxidizability, indicating oxidative stress and cellular damage. The study concluded that cell phone EMF radiation inhibits root growth by inducing oxidative stress despite increased activities of antioxidant enzymes.
Sharifian A, Gharavi M, Pasalar P, Aminian O · 2009
Researchers measured antioxidant markers in 46 spot welders occupationally exposed to extremely low frequency magnetic fields and compared results with a non-exposed control group. In the red blood cells of exposed workers, SOD activity decreased by 22% and GPX activity decreased by 12.3%, both statistically significant. Total serum antioxidant status showed no significant difference between the two groups. The researchers concluded that ELF-MF could influence red blood cell antioxidant activity and might act as an oxidative stressor.
Henrykowska G et al. · 2009
Researchers exposed human blood platelet suspensions for 15 minutes to a 50 Hz magnetic field of different shapes at a flux density of 10 mT. The study measured catalase and superoxide dismutase activity, malondialdehyde concentration, and free radical generation in human blood platelets. Free radicals, malondialdehyde, and catalase all showed increased values compared with the initial level regardless of field shape, while superoxide dismutase activity was lower than at the onset of the experiment.
Ciejka EB, Goraca A · 2009
The study tested whether a time-variable magnetic field affects heart rate and plasma antioxidant capacity. Tests were performed on Sprague-Dawley rats exposed to the magnetic field at a frequency of 40 Hz and induction of 7 mT for 30 and 60 minutes. A significant decrease of the heart rate was observed after 14 days of exposure. Exposure at 60 minutes for 14 days caused a significant decrease of the organism antioxidant defence.
Di Loreto S et al. · 2009
Researchers investigated the effects of exposures to two different 50 Hz sinusoidal ELF magnetic field intensities, 0.1 and 1 mT, on maturing rat cortical neurons. Exposure positively affected cell viability and reduced apoptotic death, with no significant effects on the main antioxidative defences. Linear regression analysis suggested a positive correlation between reduced glutathione and ROS levels in 1 mT magnetic-field-exposed cells. The researchers also observed brain-derived neurotrophic factor over-expression and interleukin 1β-dependent regulation of pro-survival signaling pathways following exposure.
