Kumlin T et al. · 2007
Researchers exposed young male Wistar rats to a 900 MHz mobile phone signal for 2 h/day on 5 days/week. After 5 weeks of exposure at whole-body average specific energy absorption rates of 0.3 or 3.0 W/kg or sham exposure, rats were assessed for behavioral and morphological changes. No degenerative changes, dying neurons, or effects on blood-brain barrier leakage were detected, and no group differences appeared in the open-field, plus maze, or acoustic startle response tests. In the water maze test, significantly improved learning and memory were detected in rats exposed to RF fields.
Brillaud E, Piotrowski A, de Seze R · 2007
Researchers measured GFAP expression in rat brains 2, 3, 6, and 10 days after a single 15-minute 900 MHz GSM exposure at a brain averaged SAR of 6 W/kg. A statistically significant increase in GFAP stained surface area was observed 2 days after exposure in the frontal cortex and the caudate putamen. A smaller statistically significant increase was noted 3 days after exposure in those same areas and in the cerebellum cortex. The researchers concluded this was a temporary effect, probably due to a hypertrophy of glial cells, and noted that whether the effect could be harmful remains to be studied.
Zhao R, Zhang S, Xu Z, Ju L, Lu D, Yao G. · 2007
Researchers investigated whether 1800 MHz radiofrequency electromagnetic fields could influence gene expression in rat neurons. Among 1200 candidate genes, 24 were up-regulated and 10 were down-regulated after 24 hours of intermittent exposure at a SAR of 2 W/kg. The researchers concluded that gene expression in rat neurons could be altered by exposure to radiofrequency electromagnetic fields under their experimental conditions.
Unknown authors · 2006
Rats were given 10-min access to a novel saccharin solution and then restrained within a 14-T magnet for 30 min. In experiment 1, males were compared with females across the estrous cycle after a single MF exposure. Females circled more and acquired a more persistent CTA than males; circling was highest on the day of estrus. In experiment 2, the effects of three MF exposures were compared among intact rats, ovariectomized females, and ovariectomized females with steroid replacement. Compared with intact rats, ovariectomy increased circling; estrogen replacement blocked the increase, and males acquired a stronger initial CTA but extinguished faster than intact or ovariectomized females.
Unknown authors · 2006
Researchers used the micronucleus test with CREST antibody staining to assess clastogenic and aneugenic effects of a 50 Hz, 650 muT magnetic field. Newborn mice were exposed during the entire 21-day intra-uterine period, and adult mice were exposed for the same duration. Newborn mice showed a significant increase in micronuclei frequencies, with most induced micronuclei being CREST-negative chromosome fragments. ELF exposure caused a two-fold increase in CREST-negative micronuclei and a four-fold increase in CREST-positive micronuclei in newborn mice. No significant effect was observed in exposed adult mice.
Unknown authors · 2006
Researchers investigated effects of electromagnetic fields on DNA damage in preimplantation mouse embryos using gammaH2AX foci formation as an indicator. EMFs decreased the cleavage rate of preimplantation mouse embryos. The decreasing effect was related to DNA damage shown by gammaH2AX foci formation. Noise magnetic fields or wortmannin inhibited the EMF-induced gammaH2AX foci formation. EMFs could activate the DNA damage-repair mechanism by recruiting Rad50 to damaged DNA sites.
Unknown authors · 2006
Researchers screened genes responsive to brief magnetism in cultured rat hippocampal neurons using differential display analysis. They identified Ntan1 as a magnetism-responsive gene in rat brain. Northern blot analysis showed that Ntan1 mRNA increased about three-fold after 3 hours in response to brief magnetism. Brief magnetism induced degradation of MAP2 without affecting cell morphology or viability, and this degradation was prevented by a selective inhibitor of the 26S proteasome. Overexpression of Ntan1 using a recombinant adenovirus vector decreased MAP2 protein expression in hippocampal neurons.
Unknown authors · 2006
Researchers exposed male adult rats to a static magnetic field of 128 mT for one hour per day over 30 days. Exposure did not change epididymal sperm count, sperm motility, or genital organ weight. Testicular and plasma testosterone levels decreased significantly in exposed rats. Oxidative stress markers malondialdehyde, metallothioneins, and 8-oxo-dG increased in the testis. Antioxidant enzymes CAT, GPx, and mitochondrial Mn-SOD decreased, while cytosolic CuZn-SOD activity was unchanged.
Unknown authors · 2006
Researchers investigated the effect of acute UHF-EMF exposure on non-enzymatic antioxidant defense and lipid and protein oxidative damage in the rat frontal cortex and hippocampus. They used malondialdehyde (MDA) and carbonyl assays to assess lipid and protein oxidative damages, respectively. No changes in lipid and protein damage, and also in non-enzymatic defense were found in frontal cortex or hippocampus. The results suggest that acute UHF-EMF exposure is not able to produce detectable oxidative stress in rats from any age tested.
Unknown authors · 2006
Orientation and pain sensitivity are affected by low-frequency magnetic fields near Earth's field strength. These effects often depend on visible light being present. Mice in a shielded dark environment showed altered nociception, but visible light during shielding eliminated most shielding effects.
Unknown authors · 2006
The hypothesis predicts optimal ameliorating effects on experimental allergic encephalomyelitis at derived intensities of about 35 and 70 nT and a frequency of 7 Hz. These predictions were congruent with prior rat experiments using magnetic field strengths of about 1-5000 nT at 0.5, 7, 40, or 60 Hz. The model proposes that weaker fields in the nanoTesla to picoTesla range would optimally affect micromolar melatonin concentrations and that mitochondrial proton gradients may be critical. The model offers an alternative explanation to variations of Faraday's Law and the Boltzmann constant that have been used to dismiss biological effects from weak magnetic fields.
Unknown authors · 2006
Researchers exposed female mice to 50 Hz, 1.2 mT electromagnetic fields for 8 hours per day throughout pregnancy. Exposed dams gained weight more slowly (29.0% vs 47.8%) and had a lower producing rate (60% of controls), with miscarriages, fetal loss, and malformed fetuses observed. The average number of offspring per mouse decreased (11 ± 1.6 vs 7 ± 2.0), and prenatally exposed offspring showed slower weight gain in the first two weeks and delayed eye opening and tooth eruption.
Unknown authors · 2006
Researchers studied the effect of 50 Hz electromagnetic field on the thyroid gland using light and transmission electron microscopes. Two-month-old male rats were exposed to an EMF of 100-300 μT and 54-160 V m-1 for 4 h a day, 5 days a week for 1 month. The EMF group showed a predominance of microfollicles with less colloid content and dilated blood capillaries. Stereological counting revealed a statistically significant increase in the volume density of follicular epithelium, interfollicular tissue, blood capillaries, and the thyroid activation index, while the volume density of colloid significantly decreased.
Whitehead TD, Moros EG, Brownstein BH, Roti Roti JL · 2006
Researchers performed in vitro experiments with C3H 10T(1/2) mouse cells to test whether FDMA or CDMA modulated RF radiation induces changes in gene expression. Cells were exposed to either modulation for 24 h at a specific absorption rate (SAR) of 5 W/ kg. Gene expression was evaluated using the Affymetrix U74Av2 GeneChip to detect changes in mRNA levels. As a positive control, cells were exposed to 0.68 Gy of X rays and gene expression was evaluated 4 h after exposure. For both CDMA and FDMA radiation, the number of probe sets with expression changes greater than 1.3-fold was less than or equal to the expected false positives, indicating no statistically significant effect on gene expression.
Shen YH, Yu D, Fu YT, Chiang H. · 2006
Five hundred female Sprague Dawley rats received a single dose of 35 mg/kg DMBA and were divided into five groups with SARs of 0, 0.44, 1.33, and 4.00 W/kg, exposed for 4 hours per day, 5 days per week for 26 weeks. The sham-exposure group had a 37% carcinoma incidence, while the exposure groups at 0.44, 1.33, and 4.00 W/kg had incidences of 25%, 34%, and 38% respectively, with no statistically significant differences between groups. The authors concluded that the study did not provide evidence that 900 MHz GSM microwave exposure promotes DMBA-induced mammary tumor development in rats.
Sanchez S et al. · 2006
Researchers exposed five-week-old female hairless rats to GSM-900 or -1800 signals for 2 hours per day, 5 days a week, for 12 weeks. Skin thickness showed no significant difference between exposed and sham-exposed groups. Cellular proliferation measured by Ki-67 remained within normal range in exposed epidermis. Levels of filaggrin, collagen, and elastin did not differ significantly among groups.
Nasta F et al. · 2006
Masuda H et al. · 2006
Researchers exposed hairless female rats to GSM-900 or -1800 signals for 2 hours using a loop antenna on the back. The local specific absorption rate at skin level was about 5 W/kg. Skin thickness and cell toxicity did not differ between exposed and sham-exposed rats. Cell proliferation in the epidermis remained within normal range and no proliferation was seen in the dermis. Levels of filaggrin, collagen, and elastin were not significantly affected by the exposure.
Lee JS, Huang TQ, Kim TH, Kim JY, Kim HJ, Pack JK, Seo JS. · 2006
Researchers exposed human T-lymphocyte Jurkat cells and rat primary astrocytes to 1763 MHz RF radiation at SARs of 2 or 20 W/kg for 30 minutes or 1 hour while temperature was completely controlled at 37 +/- 0.2 degrees C. No detectable difference was observed in the expression levels of HSP90, HSP70, and HSP27, and the phosphorylation status of MAPKs did not change significantly. When TPA alone was applied, MAPKs were phosphorylated in a dose-dependent manner, but RF radiation did not enhance TPA-induced MAPK phosphorylation, and neither TPA nor RF radiation affected HSP induction.
Heikkinen et al. · 2006
RF radiation did not significantly affect mortality or organ-specific tumor incidence. The only significant difference was an increase in vascular tumors of the mesenteric lymph nodes in the high-RF group, but this was attributed to an unusually low rate in the sham group. Non-neoplastic findings showed isolated significant differences in lacrimal glands, lungs, liver, and skin, considered unrelated to RF radiation. The authors concluded that the results do not support co-carcinogenic effects of low-level long-term RF radiation exposure in rats.
Finnie JW, Cai Z, Blumbergs PC, Manavis J, Kuchel TR. · 2006
Researchers exposed pregnant mice to 900 MHz fields at 4 W/kg for 60 minutes daily from gestation day 1 to 19. Control mice were sham-exposed or freely mobile without restraint. Fetal brains were examined for c-fos expression in multiple regions using immunohistochemistry. No difference in c-fos immunoreactivity was found between exposed and control fetal brains.
Finnie JW, Blumbergs PC, Cai Z, Manavis J, Kuchel TR. · 2006
Pregnant mice were exposed to 900 MHz radiofrequency fields at 4 W/kg for 60 minutes daily from gestational day 1 to day 19. Fetal brains were examined for albumin extravasation in multiple regions including cerebral cortex, thalamus, basal ganglia, hippocampus, cerebellum, midbrain and medulla. No albumin extravasation was found in exposed or control brains, indicating no increase in vascular permeability.
Verschaeve L et al. · 2006
Researchers investigated combined genotoxic effects of 900 MHz radiofrequency fields and the drinking water mutagen MX in female rats over two years. MX induced DNA damage in rat brain but not in blood or liver cells. Co-exposure to RF fields and MX did not significantly increase DNA damage in blood, liver, or brain compared to MX alone. The study used alkaline comet assay and micronucleus tests on samples taken at multiple time points.
Zook BC,Simmens SJ. · 2006
Researchers exposed offspring of pregnant rats treated with ENU to pulsed RF signal for 6 hours per day, 5 days per week. The 1080 rats were randomized into pulsed RF, sham, and cage control groups. Postmortem examination found no effect of RF exposure on incidence, malignancy, volume, multiplicity, latency, or fatality of any neurogenic tumor.
Lopez-Martin E et al. · 2006
The study investigated effects of mobile-phone-type radiation on cerebral activity of seizure-prone animals. Rats pretreated with subconvulsive picrotoxin and exposed to 2 hours of GSM-modulated 900 MHz radiation suffered seizures and showed markedly increased c-Fos levels in neocortex, paleocortex, hippocampus and thalamus. Non-irradiated picrotoxin-treated rats did not suffer seizures and had significantly lower c-Fos counts. Radiation caused no such differences in rats not pretreated with picrotoxin.
