Zmyslony M, Politanski P, Rajkowska E, Szymczak W, Jajte J. · 2004
Researchers tested whether 930 MHz continuous wave electromagnetic radiation affects reactive oxygen species (ROS) levels in rat lymphocytes. Acute exposure of 5 and 15 minutes did not affect ROS levels on its own. When iron ions were added to stimulate ROS production, the ROS level was significantly greater in exposed lymphocytes after both exposure durations.
Ozguner F, Aydin G, Mollaoglu H, Gokalp O, Koyu A, Cesur G. · 2004
Researchers used thirty male Wistar-Albino rats divided into a nontreated control group, an irradiated group, and an irradiated group that also received melatonin. The irradiated group received 900 MHz radiation for 10 days at 30 minutes per day, and skin grafts were taken from the thoraco-abdominal area at the end of the tenth day. In the irradiated group, researchers observed increased thickness of stratum corneum, atrophy of epidermis, papillamatosis, basal cell proliferation, hypergranulosis, capillary proliferation, and impairment in collagen tissue distribution compared to the control group. Most of these changes, except hypergranulosis, were prevented with melatonin treatment.
Zmyślony M et al. · 2004
Zmyslony M, Rajkowska E, Mamrot P, Politanski P, Jajte J · 2004
Researchers tested whether weak 50 Hz magnetic fields affect the number of free oxygen radicals in rat lymphocytes in vitro. Rat lymphocytes were exposed for one hour to 50 Hz magnetic fields at 20, 40, or 200 μT, with the field axis either along or crosswise to Earth's static magnetic field. Only at 40 μT, when the field was directed along Earth's static magnetic field, was there a decrease in fluorescence compared to non-exposed samples.
Rollwitz J, Lupke M, Simkó M · 2004
Researchers studied the effects of 50 Hz magnetic fields on free radical production in mouse bone marrow-derived macrophages and monocytes. Exposure to the magnetic fields at a flux density of 1 mT produced a significant increase in free radical production in both cell types. The radicals produced were mainly superoxide anion radicals, found in macrophages at 33% and in their precursor cells at 24%.
Lee BC et al. · 2004
Researchers investigated whether a 60 Hz magnetic field could affect the antioxidant defense system in mouse brain by measuring chemiluminescence and superoxide dismutase (SOD) activity in brain homogenates. A chemiluminescence measure linked to oxidative stress was significantly increased in mice exposed to 60 Hz, 12 G for 3 hours compared to the sham-exposed control group. Brain SOD activity was also significantly increased in the exposed group. The researchers suggest these results indicate the field could deteriorate the antioxidant defensive system through reactive oxygen species other than superoxide radicals.
Lai H, Singh NP · 2004
Researchers investigated how magnetic field exposure affected brain cell DNA in rats. Exposure to a 60-Hz magnetic field at 0.01 mT for 24 hours caused a significant increase in DNA single- and double-strand breaks, and prolonging the exposure to 48 hours caused a larger increase. Acute magnetic field exposure also increased apoptosis and necrosis of brain cells in the rat.
Trosic I, Busljeta I, Modlic B. · 2004
Researchers used an erythrocyte micronucleus assay to investigate genetic damage in bone marrow red cells of rats exposed to radiofrequency/microwave radiation. Wistar rats were exposed to a 2.45 GHz continuous field for 2 hours daily, 7 days a week, at a power density of 5–10 mW/cm2, with a whole body average specific absorption rate calculated to be 1.25 ± 0.36 W/kg. Significant differences in polychromatic erythrocytes were found on experimental days 8 and 15, and the frequency of micronucleated polychromatic erythrocytes was also significantly increased on day 15. Comparisons after 2, 8, and 30 irradiation treatments did not reveal statistically significant differences between sham-exposed and treated subgroups.
Unknown authors · 2003
Researchers restrained rats within the bore of 7 or 14 T superconducting magnets for variable durations and assessed behavioral effects by scoring locomotor activity after release and measuring conditioned taste aversion acquisition after pairing a glucose and saccharin solution with magnetic field exposure. Magnetic field exposure at either 7 or 14 T suppressed rearing and induced tight circling. The direction of circling depended on the rat's orientation: head-up exposure produced counterclockwise circling while head-down exposure produced clockwise circling. Conditioned taste aversion was induced after three pairings with 30 minutes of 7 T exposure or after a single pairing with 1 minute of 14 T exposure.
Unknown authors · 2003
Researchers isolated pineal glands from Wistar rats at 10:00 h and exposed them to a 50 Hz, 1 mT magnetic field for 4 hours in vitro. Basal melatonin release and enzyme activities were unchanged by magnetic field exposure alone. When magnetic field exposure preceded norepinephrine addition by 30 minutes, NAT activity, HIOMT activity, and melatonin release increased significantly. This effect did not occur when magnetic field and norepinephrine were applied together or in sonicated glands.
Heikkinen P et al. · 2003
Researchers evaluated the effects of low-level radiofrequency radiation on ultraviolet-induced skin tumorigenesis in ornithine decarboxylase transgenic and non-transgenic mice. UV exposure caused macroscopic skin tumours in 11.5% of non-transgenic and 36.8% of transgenic animals. Radiofrequency radiation did not significantly affect tumour development in either mouse type, though tumour appearance was slightly accelerated in non-transgenic animals. RFR exposure did not affect urinary melatonin metabolite excretion or skin polyamine levels.
Gatta L et al. · 2003
Researchers exposed C57BL/6 mice to 900 MHz GSM-modulated radiation at SAR 1 or 2 W/kg for 2 hours per day over 1, 2, or 4 weeks. The number of spleen cells, percentages of B and T cells, and CD4/CD8 distribution were not altered by exposure. After 1 week of exposure, IFN-gamma production increased, but this effect was not seen after 2 or 4 weeks.
Dubreuil D, Jay T, Edeline JM. · 2003
Researchers exposed rats head-only to 900 MHz GSM electromagnetic fields at 1 and 3.5 W/kg for 45 minutes and compared performance with sham and control rats. In the first experiment, a slightly improved performance was found at 3.5 W/kg, but this was not seen in the delay task. In the third experiment, exploratory activity showed some effects but recognition memory was unaffected. Overall, the experiments provided no evidence that spatial or non-spatial memory is affected by this exposure.
Anane R et al. · 2003
Researchers investigated the effects of acute GSM-900 microwave exposure on the clinical parameters of the acute EAE rat model in two independent experiments with habituated and nonhabituated rats. Female Lewis rats were divided into cage control, sham exposed, and two groups exposed at 1.5 or 6.0 W/kg local SAR averaged over the brain using a loop antenna over their heads. EAE was induced with a mixture of myelin basic protein and Mycobacterium tuberculosis. The 21-day exposure at 2 hours per day had no effect on the onset, duration, or termination of the EAE crisis.
Jayanand, Behari J, Lochan R. · 2003
Researchers exposed rats with sciatic neurectomy-induced osteoporosis to modulated pulsed electromagnetic fields at a 14 MHz carrier frequency modulated at 16 Hz with 10 V peak-to-peak amplitude. The exposure produced a statistically significant increase in bone mineral density and a deceleration in the bone resorption process in the femur and tibia. The authors suggest that this effective window of pulsed radio frequency fields may be used therapeutically for osteoporosis treatment.
Yamaguchi H et al. · 2003
Sprague-Dawley rats were exposed to pulsed 1439 MHz TDMA fields at a brain SAR of 7.5 W/kg for 1 hour daily over 4 days or 4 weeks. Other rats were exposed at a brain SAR of 25 W/kg for 45 minutes daily for 4 days. Rats exposed at 25 W/kg for 4 days showed statistically significant decreases in correct choices in a T-maze reversal task, while rats exposed at 7.5 W/kg for 4 days or 4 weeks showed no performance impairments. Intraperitoneal temperature increased only at the 25 W/kg exposure level. The authors concluded that TDMA fields at levels about four times higher than cell phone emissions do not affect learning and memory when no thermal effects occur.
Desta AB, Owen RD, Cress LW. · 2003
Researchers exposed L929 murine fibroblast cells to radiofrequency radiation from a time division multiple access wireless phone operating at 835 MHz to determine the effect on ornithine decarboxylase activity. Exposure lasted 8 hours at average specific absorption rates ranging from less than 1 W/kg up to 15 W/kg, after which cells were harvested and ODC activity was measured. No statistically significant difference in ODC activity was found between exposed and sham-exposed cells at non-thermal specific absorption rates. At SARs that caused measurable heating, a dose-dependent decrease in enzymatic activity was observed and was consistent with a comparable decrease caused by non-RF-radiation heating.
Anane R et al. · 2003
Researchers tested whether whole-body exposure to GSM-900 microwaves affected tumor promotion and progression in female Sprague-Dawley rats with DMBA-induced mammary tumors. Results were negative for tumor latency, multiplicity, and volume, though in the first experiment tumor incidence was higher at 1.4 W/kg but less so at 2.2 W/kg and not at all at 3.5 W/kg. Overall the results were considered rather inconsistent and did not bring new evidence of a co-promoting effect of GSM-900 exposure.
Aweda MA, Gbenebitse S, Meidinyo RO · 2003
Researchers studied the effects of 2.45 GHz microwave exposure on the lipid peroxidation status of 120 Wistar rats at a power density of 6 mWcm(-2). Lipid peroxidation status in the rats was monitored for 8 weeks after irradiation using the thiobarbituric acid method. Microwave exposure raised the lipid peroxidation status from a mean control value of 4.18 x 10(-6)g 1(-1) to a maximum of 6.50 x 10(-6) g 1(-1) within the first 24 hours, after which it gradually returned toward the control value. The results demonstrated that microwave exposures cause a significant increase in lipid peroxidation status and that ascorbic acid and alpha-tocopherol had protective effects.
Jajte J, Zmyślony M, Rajkowska E. · 2003
Researchers examined whether melatonin and vitamin E could protect rat blood lymphocytes from lipid peroxidation caused by iron ions and a 7 mT static magnetic field in vitro. Simultaneous exposure to the 7 mT static magnetic field and iron ions produced a significant increase in lipid peroxidation end-products compared with control samples and those exposed to the field alone. When cells were pre-treated with melatonin or vitamin E before that same exposure, lipid peroxidation was significantly reduced, and melatonin was less effective than vitamin E under these conditions.
Unknown authors · 2002
Researchers exposed 10-day-old mice to a 1 mT, 60 Hz magnetic field for 2 hours and measured DNA damage at multiple time points using the alkaline comet assay. They also measured apoptosis in the external granule cell layer of the cerebellum at 0 and 24 hours using the TUNEL assay. Increased DNA damage was detected by tail ratio at 2 hours but not by the other comet assay parameters, and no increase in apoptosis was observed compared to sham-exposed mice.
Unknown authors · 2002
Female Sprague Dawley rats were MF or sham exposed for 2 weeks at a flux density of 100 microTesla. Proliferation of epithelial cells in the mammary tissue and adjacent skin was examined by in vivo labeling with bromodeoxyuridine (BrdUrd) and in situ labeling of Ki-67 protein by the antibody MIB-5. MF exposure significantly enhanced BrdUrd and Ki-67 labeling in the mammary epithelium, indicating a marked increase in cell proliferation. Melatonin levels in pineal or mammary glands were not affected by MF exposure. Topical application of 12-O-tetradecanoylphorbol-13-acetate increased BrdUrd and Ki-67 labeling in skin epithelial cells, particularly hair follicles, but not in mammary tissue.
Takahashi S et al. · 2002
Researchers investigated the mutagenic potential of 1.5 GHz electromagnetic near fields using brain tissues of Big Blue mice. Male BBM were locally exposed to EMF in the head region at 2.0, 0.67, and 0 W/kg specific absorption rate for 90 min/day, 5 days/week, for 4 weeks. There was no significant variation in the frequency of independent mutations of the lacI transgene in the brains. Deletion mutations were slightly increased in both the high and low EMF exposure groups as compared with the sham-exposed group, but the differences were not statistically significant.
Logani MK, Agelan A, Ziskin MC. · 2002
The study examined the effect of millimeter electromagnetic waves on catalase activity in mouse blood to understand mechanisms involved in its reduction. SKH-1 hairless mice were irradiated on their midbacks with 42.2±0.2 GHz millimeter waves at an incident power density of 31±5 mW/cm2 and a peak SAR of 622±100 W/kg. MW irradiation before or after cyclophosphamide administration did not significantly reduce the toxic effect of cyclophosphamide on catalase activity in mouse blood.
Dubreuil D, Jay T, Edeline JM. · 2002
