Zeng QL, Weng Y, Chen GD, Lu DQ, Chiang H, Xu ZP · 2006
Researchers exposed MCF-7 human breast cancer cells to GSM 1800 MHz RF EMF at 3.5 W/kg SAR for various durations and modes. They used 2-dimensional electrophoresis and PDQuest software to analyze protein expression. No differential proteins were found after 6 hours of continuous exposure. Eighteen differential proteins were detected after 3-hour intermittent exposure and seven after 12-hour continuous exposure. The analysis suggested that the differentially expressed proteins should be related to biosynthesization, signal transduction, and DNA damage and repair.
Vanderwaal RP, Cha B, Moros EG, Roti Roti JL. · 2006
The radiofrequency exposures were 847 MHz TDMA at a SAR of 5 W kg-1 for 1, 2, or 24 h and 900 MHz GSM at a SAR of 3.7 W kg-1 for 1, 2, or 5 h. Acute hyperthermia at 45 degrees C increased the proportion of higher phosphorylated forms of HSP27. Exposure of HeLa S3 cells to 5 W kg-1 TDMA for 1, 2, or 24 h did not induce significant differences in HSP27 phosphorylation compared to incubator control or sham.
Trosic I, Busljeta I. · 2006
Researchers exposed rats to 2.45 GHz microwave radiation at a whole-body SAR of 1.25+/-0.36 W/kg for 2 hours per day, 7 days a week. Bone marrow polychromatic erythrocytes increased on days 8 and 15, and peripheral blood polychromatic erythrocytes increased on days 2 and 8. Bone marrow micronucleated PCE frequency increased on day 15, and peripheral blood micronucleated PCEs increased on day 8, but all values declined nearly to control levels by the end of the experiment.
Takashima Y et al. · 2006
Researchers exposed cells to radio frequency electromagnetic fields at 2.45 GHz to examine cell growth, survival, and cell cycle distribution across a wide range of specific absorption rates. When cells were exposed to a continuous RF field at SARs from 0.05 to 100 W/kg for 2 h, cellular growth rate, survival, and cell cycle distribution were not affected. At 200 W/kg, the cell growth rate was suppressed and cell survival decreased, and the temperature of the medium rose to 44.1 degrees C. The researchers suggested that the proliferation disorder is caused by the thermal effect.
Paulraj R, Behari J · 2006
The control group was sham irradiated. The study revealed a statistically significant decrease in PKC activity in the hippocampus compared to the rest of the brain and controls. Electron microscopy showed an increase in glial cell population in the exposed group.
Hoyto A, Sihvonen AP, Alhonen L, Juutilainen J, Naarala J · 2006
Researchers investigated the effects of low-level radiofrequency radiation and elevated temperature on ornithine decarboxylase (ODC) activity in murine L929 fibroblasts. RF radiation did not affect cellular ODC activity. A slight temperature increase of 0.8-0.9 degrees C in the exposure system led to decreased ODC activity, which was verified by exposing cells to different temperatures in incubators.
Capri M et al. · 2006
Researchers exposed human peripheral blood mononuclear cells from young and elderly donors to radiofrequency radiation at 1,800 MHz and a Specific Absorption Rate of 2 W/kg, with or without mitogenic stimulation. However, RF exposure produced a slight but significant downregulation of CD95 expression in stimulated CD4+ T lymphocytes from elderly donors only.
Zhang DY, Xu ZP, Chiang H, Lu DQ, Zeng QL. · 2006
Researchers studied the effects of GSM 1800 MHz radiofrequency electromagnetic fields on DNA damage in Chinese hamster lung cells. Cells were intermittently exposed to GSM 1800 MHz RF EMF at a SAR of 3.0 W/kg for either 1 hour or 24 hours, using a pattern of 5 minutes on and 10 minutes off. After 24 hours of exposure, the percentage of gammaH2AX foci positive cells was 37.9 +/- 8.6%, significantly higher than the sham-exposed group at 28.0 +/- 8.4%. The 1-hour exposure showed no significant difference from sham exposure.
Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW. · 2006
Cultured LECs were exposed to 217 Hz modulated 1.8 GHz microwave radiation at specific absorption rates of 0, 1, 2, 3, and 4 W/kg for 2 hours. DNA single strand breaks were detected with comet assay at 0, 30, 60, 120, and 240 minutes after irradiation. At 1 and 2 W/kg, the difference in DNA breaks between exposure and sham exposure groups was not significant at any detection time. At 3 and 4 W/kg, differences were significant immediately and 30 minutes after irradiation, with the difference disappearing after one hour in the 3 W/kg group but persisting in the 4 W/kg group.
Lixia S et al. · 2006
Researchers exposed human lens epithelial cells (hLEC) to a 1.8 GHz GSM radiofrequency field at SARs of 1, 2, and 3 W/kg for 2 hours and then measured DNA damage, Hsp70 expression, and cell proliferation. DNA breaks at 1 and 2 W/kg were not significantly different from controls at any time point, while the 3 W/kg dose showed significantly increased DNA damage only at 0 and 30 minutes after exposure. Hsp70 protein expression was significantly increased at 2 and 3 W/kg, but Hsp70 mRNA expression did not change in any group, and cell proliferation was unaffected at all doses.
Whitehead TD et al. · 2005
The study aimed to confirm a previous report that CDMA and FDMA radiation increased Fos levels as cells entered plateau phase. Fos mRNA levels were not significantly different from sham exposure at either SAR level for any signal modulation. Therefore, the earlier results could not be confirmed.
Miyakoshi J et al. · 2005
Researchers exposed human glioma MO54 cells to a continuous wave 1950 MHz RF field at SARs of 1, 2, and 10 W/kg for up to 2 hours. Cell growth was assessed by counting cell numbers up to 4 days after exposure. RF exposure at 2 and 10 W/kg did not affect the growth of MO54 cells. However, exposure at 10 W/kg for 1 and 2 hours significantly decreased the protein level of phosphorylated Hsp27 at serine 78.
Lim HB, Cook GG, Barker AT, Coulton LA. · 2005
Researchers exposed human peripheral blood to 900 MHz fields at specific absorption rates of 0.4, 2.0, and 3.6 W/kg for durations of 20 minutes, 1 hour, and 4 hours. Heat stress at 42 degrees Celsius increased the number of cells expressing HSP70 and HSP27 in a time-dependent manner. No statistically significant difference in stress protein expression was detected after RF-field exposure.
Lee JS, Huang TQ, Lee JJ, Pack JK, Jang JJ, Seo JS. · 2005
Researchers exposed eight-week-old hsp70.1-deficient mice twice daily for 45 minutes with a 15-minute interval, five days a week for ten weeks at a whole-body average specific absorption rate of 0.4 W/Kg for both 849 MHz and 1763 MHz fields. They examined major tissues histopathologically, assessed cell proliferative activity immunocytochemically, measured apoptosis with a TUNEL assay, and evaluated heat shock protein expression and stress-activated kinase phosphorylation by western blot. No histopathological differences were found between sham- and RF-exposed mice, and there was no evidence of increased proliferative or apoptotic activity. Levels of HSP90, HSP70, and HSP25 showed no obvious changes, and RF exposure did not affect phosphorylation of ERK1/2, JNK1/2, or p38 MAPK.
Laszlo et al. · 2005
Researchers measured heat-shock factor DNA-binding activity in hamster, mouse, and human cells after exposure to FDMA- or CDMA-modulated microwaves at low or high SARs. The assay could detect a 10% increase in HSF activation from a 1°C temperature rise. No increase in HSF DNA-binding ability was detected from any exposure tested. The results do not support activation of the stress response by mobile communication microwaves.
Komatsubara Y et al. · 2005
Researchers exposed murine m5S cells to 2.45 GHz high-frequency electromagnetic fields for 2 hours at SARs of 5, 10, 20, 50, and 100 W/kg continuous wave and at a mean SAR of 100 W/kg pulse wave with a maximum of 900 W/kg. The effects were compared with sham-exposed controls and with mitomycin C and X-ray treatments as positive controls. No significant differences in chromosomal aberrations were observed between HFEMF-exposed cells and sham controls, while positive controls increased chromatid-type and chromosome-type aberrations.
Huang TQ, Lee JS, Kim TH, Pack JK, Jang JJ, Seo JS. · 2005
The study used 80 male ICR mice initiated with DMBA and then exposed to 849 MHz or 1,763 MHz RF radiation at 0.4 W/kg SAR for 19 weeks. No skin tumors were observed in the sham or RF-exposed groups, while the TPA positive control group had a 95% tumor incidence. Pathological examination and PCNA staining showed no differences between sham and RF-exposed groups, and cyclin D1 and c-fos expression was only detected in TPA-induced tumors. The researchers concluded that RF radiation does not act as a tumor promoter for skin tumors in this model.
Green AC et al. · 2005
Intracellular calcium concentration ([Ca(2 +) ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW x kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Exposure to TETRA (50 or 400 mW x kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.
Gorlitz BD et al. · 2005
Zeni O et al. · 2005
Researchers exposed human peripheral blood leukocytes from healthy volunteers to a 900 MHz GSM signal for 2 hours at SARs of 0.3 and 1 W/kg. DNA damage was assessed with the comet assay, chromosome aberrations and sister chromatid exchanges were measured in stimulated lymphocytes, and cell proliferation was evaluated via the mitotic index. No statistically significant differences were observed between exposed and sham-exposed samples for any of these endpoints, while positive controls showed the expected increases in DNA damage.
Lee S et al. · 2005
The study used the serial analysis of gene expression (SAGE) method to measure genome-wide gene expression changes in cultured human HL-60 cells exposed to pulsed 2.45 GHz RF fields. After a 2-hour exposure, 221 genes showed altered expression, increasing to 759 genes after 6 hours. Apoptosis-related genes were upregulated while cell cycle genes were downregulated, with no significant increase in heat shock genes.
Dovrat A et al. · 2005
Researchers used a novel experimental system to investigate localized effects of microwave radiation on bovine eye lenses in culture for over two weeks. Exposure to a few milliwatts at 1 GHz for over 36 hours affected the optical function of the lens. Self-recovery occurred when exposure was interrupted, but microscopic indicators of radiation impact remained even after macroscopic recovery.
Barteri M, Pala A, Rotella S. · 2005
Researchers exposed an aqueous solution of electric eel acetylcholinesterase to emissions from a commercial cellular phone. The exposure altered the enzyme's activity and irreversibly affected its structural and biochemical characteristics. The authors note that the results cannot determine hazardous health effects but may be a first step for further verification.
Anghileri LJ, Mayayo E, Domingo JL, Thouvenot P. · 2005
Mice were treated with 1 hour per week of radiofrequency exposure for 4 months while a sham-exposed group served as controls. The evolution of carcinogenesis was followed up to 18 months, and the maximal life span of control mice was about 24 months. All dead animals were clinically and histologically examined to give an age-determined comparative quantification of the evolving carcinogenesis. A radiocalcium tracer method permitted the evaluation of radiofrequency effects on transmembrane transport of extracellular calcium at 1 and 24 hours after exposure, and the determination of induced lipid peroxidation completed this second study.
Trosic I, Busljeta I. · 2005
Researchers exposed Wistar rats to 2.45 GHz continuous RF/MW radiation for 2 hours daily, 7 days a week, at 5–10 mW/cm², with subgroups receiving 4, 16, 30, and 60 total hours of exposure. The frequency of micronucleated bone marrow erythrocytes was significantly increased after 15 irradiation treatments. No statistically significant differences in micronucleus frequency were observed after 2, 8, or 30 irradiation treatments.
