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.
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.
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.
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.
Maskey D, Kim HJ, Kim HG, Kim MJ. · 2012
Researchers exposed mice to 835 MHz radiofrequency at SAR values of 1.6 W/kg and 4.0 W/kg for one month to study effects in the hippocampus. Compared with a sham control group, both exposed groups showed decreased calbindin D28-k and calretinin, loss of immunoreactive cells, and increased GFAP with hypertrophic cytoplasmic processes. The group exposed at 4.0 W/kg showed a more prominent decrease in calbindin and calretinin, and more prominent GFAP immunoreactivity, than the group exposed at 1.6 W/kg.
Lu Y et al. · 2012
Researchers exposed Wistar rats to 2.45 GHz pulsed microwave irradiation at a power density of 1 mW/cm2 for 3 hours per day for up to 30 days. Microwave exposure induced spatial learning and memory impairments in rats, and reduced hippocampal glucose uptake in the absence or presence of insulin. Blood glucose and insulin levels were not affected, but spatial memory deficits were reversed by systemic glucose treatment.
Liu YX et al. · 2012
Researchers exposed rat astrocytes and C6 glioma cells to 1950-MHz TD-SCDMA electromagnetic fields for 12, 24, and 48 hours to investigate whether the radiation would alter glial cell biology and act as a tumor-promoting agent. After 48 hours of exposure, mitochondria were damaged and significant apoptosis of astrocytes was induced, with increased expression of bax and a reduced level of bcl-2. Astrocytes did not form tumors in either the control or exposed groups, and exposed C6 glioma cells showed no significant differences in biological features or tumor formation ability compared with unexposed cells.
Li Y, Shi C, Lu G, Xu Q, Liu S. · 2012
Researchers exposed 8-week-old Wistar rats to near-field radiation at 0.52–1.08 W/kg for 2 hours per day for 1 month. Behavioral changes were examined using the Morris water maze, and the irradiated rats exhibited impaired performance compared with the sham-irradiated rats. The morphological changes included mitochondrial degenerations, fewer synapses, and shorter postsynaptic densities in the radiated rats.
Fragopoulou AF et al. · 2012
Researchers investigated the effects of two sources of electromagnetic fields on the proteome of the cerebellum, hippocampus, and frontal lobe in Balb/c mice following long-term whole body irradiation. Across both exposure types, 143 proteins showed significantly altered expression, ranging from as low as 0.003 fold downregulation up to 114 fold overexpression. The altered proteins included neural function related proteins, heat shock proteins, cytoskeletal proteins, and proteins of brain metabolism across nearly all brain regions studied.
Calabrò E et al. · 2012
Cogulu O. · 2012
Researchers exposed mouse brain cell cultures to radiofrequency waves to evaluate genotoxic effects. The cultures were exposed to 10.715 GHz signals at a specific absorption rate of 0.725 W/kg for 6 hours over 3 days at 25°C. The study measured changes in the micronucleus assay and in the expression of 11 proapoptotic and antiapoptotic genes. The micronuclei rate increased 11-fold and STAT3 expression decreased 7-fold in the exposed cell cultures.
Chen G, Lu D, Chiang H, Leszczynski D, Xu Z. · 2012
Researchers used the yeast Saccharomyces cerevisiae to study how exposure to extremely low frequency magnetic fields and radiofrequency EMF affects gene expression. Yeast cells were exposed for 6 hours to either 0.4 mT 50 Hz ELF-MF or 1800 MHz RF-EMF at a specific absorption rate of 4.7 W/kg. The study found no confirmed gene expression changes from ELF-MF exposure, and only the expressions of SMC3 and AQY2 were confirmed as responsive to RF-EMF.
Unknown authors · 2011
Researchers studied the effect of extremely low-frequency electromagnetic fields on bovine lung membrane carbonic anhydrase. A 75 Hz field decreased enzyme activity by 17% with a threshold of about 0.74 mT. The effect was independent of exposure duration and completely reversible. Solubilizing the enzyme with Triton eliminated the field effect, indicating the membrane linkage is essential.
Unknown authors · 2011
Researchers investigated the effects of extremely low frequency EMF on intracellular calcium mobilization and cellular function in RBL 2H3 cells. Exposure to EMF at 0.1 or 1 mT for 4 or 16 hours did not produce cytotoxic effects in RBL 2H3 cells. Melittin, ionomycin, and thapsigargin each dose-dependently increased intracellular calcium concentration. The calcium increases induced by these agents were not affected by EMF exposure. EMF exposure also did not affect basal or melittin-induced beta-hexosaminidase release.
Unknown authors · 2011
Researchers tested whether separate cell populations physically interfere when incubated in close proximity. They used immortalized mouse fibroblasts (NIH3T3) and adult human microvascular endothelial cells (HMVECad) seeded in separate polystyrene Petri dishes. Dishes with NIH3T3 cells were placed on top of dishes with endothelial cells at distances of 4mm and 11mm. Cell number and morphology of both cell types were modified in dishes without the black filter, suggesting signals transmitted through the polystyrene walls affected proliferation and morphology.
Unknown authors · 2011
Unknown authors · 2011
Researchers exposed cultured human dermal papilla cells to 1,763 MHz RF radiation at a specific absorption rate of 10 W/kg. IGF-1 mRNA expression was significantly induced, leading to increased BCL-2 and CCND1 proteins and increased phosphorylation of MAPK1. Exposure for 1 hour per day over 7 days significantly enhanced hair shaft elongation in ex vivo hair organ cultures. In follicular matrix keratinocytes, Ki-67 expression increased and TUNEL signaling decreased. The authors suggest that 1,763 MHz RF exposure stimulates hair growth in vitro through IGF-1 induction in dermal papilla cells.
Unknown authors · 2011
In vitro studies used several cell types from both humans and rodents, including primary cells, embryonic cell lines, undifferentiated cancer cell lines, and stem cells. Gene and protein expression were not significantly changed by exposure in nine out of 15 studies. Genotoxicity was evaluated in 13 papers and in most of these studies no DNA damage was detected; eight studies failed to demonstrate induction of apoptosis and three reported lack of oxidative stress induction by RF exposures. Few papers have been published on low level exposure of immature animals and the available results are very limited, but the evidence does not indicate that prenatal or early postnatal exposures are associated with acute adverse responses or long-term detrimental changes.
Roux D et al. · 2011
Bourthoumieu S et al. · 2011
Researchers investigated the potential induction of genomic instability by GSM-900 MHz radiofrequency radiation in human amniotic cells exposed for 24 h to average-specific absorption rates (SAR) of 0.25, 1, 2 and 4 W/kg. The rate of aneuploidy of chromosomes 11 and 17 was determined by interphase FISH immediately after independent exposure of three different donors for 24 h. No significant change in the rate of aneuploidy of chromosomes 11 and 17 was found at average SAR up to 4 W/kg.
Masuda H et al. · 2011
Researchers exposed rat brain membrane fractions and human 5-HT1B receptors in C6-glial cells to 50-Hz magnetic field at 1 mT. No significant difference was found in the affinity constant of serotonin for the 5-HT1B receptor between exposed and sham-exposed rat membranes. The same lack of affinity change was confirmed using a chemical agonist and in human 5-HT1B receptors in C6-glial cells. Forskolin-stimulated cAMP production inhibited by serotonin was also not modified by exposure in C6-glial cells.
