Czyz J et al. · 2004
Researchers exposed wild-type and p53-deficient embryonic stem cells to GSM-217 and GSM-Talk modulated electromagnetic fields at 1.71 GHz. GSM-217 exposure significantly increased hsp70 mRNA levels in p53-deficient cells, with a transient rise in c-jun, c-myc, and p21 levels only in those cells. GSM-Talk exposure produced no gene expression changes in either cell type, and cardiac differentiation and cell cycle were unaffected by GSM-217.
Ji S, Oh E, Sul D, Choi JW, Park H, Lee E. · 2004
Researchers used the Comet assay to measure Olive Tail Moment and Tail DNA% in T-cells, B-cells, and granulocytes before and after exposure. Olive Tail Moment and Tail DNA% in B-cells and granulocytes increased significantly after exposure.
Yao K, Wang KJ, Sun ZH, Tan J, Xu W, Zhu LJ, Lu de Q. · 2004
Researchers exposed cultured rabbit lens epithelial cells to continuous 2,450 MHz microwave radiation at power densities of 0.10, 0.25, 0.50, 1.00, and 2.00 mW/cm2 for 8 hours. P27Kip1 protein expression increased markedly but its mRNA levels did not change, and P21WAF1 protein and mRNA levels showed no detectable differences between exposed and control groups.
Pyrpasopoulou A et al. · 2004
Researchers exposed pregnant rats to pulsed GSM-like radiofrequency radiation at 9.4 GHz and 5 microW/cm2 during early gestation. They measured bone morphogenetic protein and receptor expression in newborn kidneys using semi-quantitative duplex RT-PCR. Exposure increased BMP-4 and BMPR-IA expression and decreased BMPR-II expression, with statistical significance depending on exposure timing. Immunohistochemistry and in situ hybridization revealed aberrant expression and localization of these molecules. The authors suggest these molecular changes do not affect renal organogenesis but may reflect a developmental delay, and that exposure timing influences effects.
Markkanen A et al. · 2004
Researchers exposed wild-type and cdc48-mutant yeast cells to 900 or 872 MHz RF fields with or without UV radiation at elevated temperature. Amplitude modulated RF exposure significantly enhanced UV-induced apoptosis in cdc48-mutated cells, but unmodulated fields at the same SAR had no effect. Apoptosis was measured using the annexin V-FITC method with flow cytometry.
Koyama S, Isozumi Y, Suzuki Y, Taki M, Miyakoshi J. · 2004
Researchers exposed Chinese hamster ovary CHO-K1 cells to 2.45-GHz electromagnetic fields for 2 hours at SARs of 5, 10, 20, 50, 100, and 200 W/kg to study micronucleus formation. Micronucleus frequency in cells exposed at SARs lower than 50 W/kg did not differ from sham-exposed controls. At SARs of 100 and 200 W/kg, micronucleus frequency was significantly higher than in sham-exposed controls. The researchers also found that micronucleus frequency increased in a temperature-dependent manner when cells were heat-treated at temperatures from 38 to 42 degrees C.
Zmyślony M et al. · 2004
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.
Koyama S et al. · 2004
Researchers tested whether an extremely low-frequency magnetic field (ELFMF) could affect mutations caused by hydrogen peroxide in pTN89 plasmids. Mutations were detected in the supF gene carried by the plasmids in Escherichia coli. The mutation frequency was 2.28×10−4 for hydrogen peroxide treatment alone, and 5.81×10−4 when the ELFMF was applied at the same time. No mutations were observed with ELFMF exposure alone, and the researchers indicated that the ELFMF may potentiate hydrogen peroxide-induced mutation.
Ding GR et al. · 2004
Researchers tested whether exposure to an extremely low frequency magnetic field affects hydrogen peroxide-induced cell death in human leukaemia HL-60 cells. Simultaneous treatment with the magnetic field and hydrogen peroxide for 24 hours significantly increased the number of apoptotic and necrotic cells compared with cells treated with hydrogen peroxide alone. The researchers found that active caspase-7 protein levels were higher in cells exposed to both the magnetic field and hydrogen peroxide than in those treated with hydrogen peroxide alone, and that poly(ADP-ribose) polymerase cleavage occurred earlier under combined exposure.
Sarimov R et al. · 2004
Researchers exposed lymphocytes from seven healthy persons to GSM microwaves at different frequencies in the range of 895-915 MHz and measured changes in chromatin conformation. A 30-min exposure at 900 and 905 MHz produced statistically significant condensation of chromatin in lymphocytes from 1 of 3 tested donors. Stronger effects were found following 1-h exposure, with chromatin condensation in 3 donors and decondensation in 1 donor. The observed chromatin changes were similar to effects of heat shock within the temperature window of 40/spl deg/C-44/spl deg/C.
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.
Busljeta I, Trosic I, Milkovic-Kraus S. · 2004
The study observed erythropoietic changes in rats subchronically exposed to radiofrequency microwave radiation at a nonthermal level. Adult male Wistar rats were exposed to 2.45 GHz continuous RF/MW fields for 2 hours daily, 7 days a week, at 5 – 10 mW/cm2. In exposed animals, erythrocyte count, haemoglobin and haematocrit were increased in peripheral blood on irradiation days 8 and 15. Anuclear cells and erythropoietic precursor cells were significantly decreased in the bone marrow on day 15, while micronucleated cells' frequency was increased.
Zeni, O., Schiavoni, A. · 2003
Researchers exposed human peripheral blood lymphocytes from 20 healthy donors to 900 MHz electromagnetic fields under various conditions. Exposures included continuous-wave and GSM-modulated signals at specific absorption rates of 1.6 W/kg and 0.2 W/kg with different intermittent patterns. No statistically significant differences were found in micronucleus frequency or cell cycle kinetics across any exposure condition.
Scarfi MR et al. · 2003
The study aimed to investigate the genotoxic effect of THz radiation on human peripheral blood lymphocytes after 20 minutes of exposure to 1 mW average power Free Electron Laser radiation at 120-140 GHz. Nine healthy donors were employed and the cytokinesis block technique was used to measure micronucleus frequency and cell proliferation. The results indicated that the electromagnetic conditions did not alter micronucleus frequency or cell proliferation, suggesting no direct chromosomal damage or cell cycle alteration (p > 0.05).
McNamee, J. · 2003
Unknown authors · 2003
Researchers exposed CHO-K1 cells to high-frequency electromagnetic fields for 18 hours at SARs of 13, 39, and 50 W/kg and found no increase in micronucleus frequency compared to sham-exposed cells. At higher SARs of 78 and 100 W/kg, micronucleus frequency increased significantly in the middle well at 100 W/kg and in the outer well at 78 W/kg. When combined with bleomycin, exposure at 100 W/kg in the middle well and 78 W/kg in the outer well further increased micronucleus frequency beyond bleomycin alone. A high-temperature control at 39°C also significantly increased micronucleus frequency.
Unknown authors · 2003
Unknown authors · 2003
Researchers exposed cultured fibroblasts from six healthy donors of different ages to intermittent ELF-EMF at 50 Hz and 1 mT for 1 to 24 hours. Basal DNA strand break levels correlated with donor age. The maximum DNA strand break response occurred at 15 to 19 hours of exposure. This response was more pronounced in cells from older donors, suggesting an age-related decrease in DNA repair efficiency.
Unknown authors · 2003
Researchers exposed cultured human diploid fibroblasts to intermittent ELF electromagnetic fields. DNA damage was measured using alkaline and neutral comet assays. Exposure at 50 Hz sinusoidal, 1-24 h, 20-1,000 mu T, with a 5 min on/10 min off pattern induced dose-dependent and time-dependent DNA single-strand and double-strand breaks. Effects were observed at magnetic flux densities as low as 35 mu T, well below ICNIRP guidelines. The induced comet tail factors returned to normal within 9 h after exposure ended.
Zhang MB, Jin LF, He JL, Hu J, Zheng W. · 2003
The study aimed to investigate the combined DNA-damaging effects of low-intensity 2,450 MHz microwave radiation with three chemical mutagens on human lymphocyte DNA. Microwave exposure alone did not significantly increase comet tail length compared with controls at 0 h or 21 h incubation. When lymphocytes were incubated with 30.00 micro mol/L or 3.00 micro mol/L MMC, microwave exposure significantly increased comet tail lengths compared with MMC alone. Combinations of microwave with BLM or MMS did not produce significantly greater DNA damage than BLM or MMS alone.
Zeni et al. · 2003
Vijayalaxmi, Sasser LB, Morris JE, Wilson BW, Anderson LE. · 2003
Timed-pregnant Fischer 344 rats and their nursing offspring were exposed to a far-field 1.6 GHz Iridium signal for 2 h/day, 7 days/week. The offspring then received chronic head-only near-field exposure to a 1.6 GHz signal for 2 h/day, 5 days/week over 2 years. Near-field exposures were conducted at brain SARs of 0.16 or 1.6 W/kg. The incidence of micronuclei in bone marrow did not differ significantly between exposed, sham-exposed, and cage control rats.
Port M, Abend M, Romer B, Van Beuningen D. · 2003
Researchers exposed human leukemia HL-60 cells in vitro to high-frequency electromagnetic fields 25 times higher than ICNIRP occupational reference levels. Cells were harvested at 0, 24, 48, and 72 hours after exposure, and apoptosis, micronuclei, abnormal cells, and expression of 1176 genes were measured. No significant changes were found in apoptosis, micronucleation, abnormal cells, or differential gene expression.
McNamee et al. · 2003
Researchers examined the effect of 24-hour continuous-wave and pulsed-wave 1.9 GHz radiofrequency fields on primary DNA damage and micronucleus induction in human leukocyte cultures. No significant differences in primary DNA damage were observed between sham controls and any exposed cultures when assessed by the alkaline comet assay immediately after exposure. Similarly, no significant differences were found in micronucleus incidence, micronucleated binucleated cells, binucleated cell frequency, or proliferation index between sham and exposed cultures.
