Miyakoshi J, Koji Y, Wakasa T, Takebe H · 1999
Researchers exposed Chinese hamster ovary K1 cells to 5 mT ELFMF at 60 Hz for up to 6 weeks with or without X-irradiation. Long-term exposure to 5 mT ELFMF alone did not increase mutant frequency of the HPRT gene. However, exposure to 5 mT ELFMF after X-irradiation enhanced the X-ray-induced mutation rate. As little as 1 week of ELFMF exposure after X-irradiation increased the mutation rate.
Lu ST, Mathur SP, Akyel Y, Lee JC · 1999
Researchers exposed male Wistar-Kyoto rats to ultrawide-band electromagnetic pulses at 0.5-kHz and 1-kHz for 6 minutes. They measured cardiovascular functions including heart rate, systolic, mean, and diastolic pressures using a noninvasive tail-cuff sphygmomanometer. Exposure caused a significant decrease in arterial blood pressure that was robust, consistent, and persistent, while heart rate did not change. Cardiovascular functions were evaluated from 45 minutes to 4 weeks after exposure.
Higashikubo R et al. · 1999
Researchers exposed Fischer 344 rats implanted with 9L gliosarcoma cells to 835.62 MHz FMCW or 847.74 MHz CDMA fields with a nominal brain specific absorption rate of 0.75 +/- 0.25 W/kg. The animals were exposed for 4 hours a day, 5 days a week, starting 4 weeks before tumor implantation and continuing up to 150 days after. Sham-exposed rats injected with 2 to 10 cells had a median survival of 70 days with 27% surviving to 150 days; those with 11 to 36 cells had a median survival of 52 days and 14% final survival; those with 37 to 100 cells had a median survival of 45 days and 0% survival. Statistical comparison showed no significant differences in survival curves between RF-exposed and sham-exposed animals in any of the three cell-dose groups.
Unknown authors · 1999
Researchers investigated the effect of 50 Hz magnetic fields on the cytosolic calcium oscillator in Jurkat E6.1 cells at field strengths from 0 to 0.40 mT root mean square. The total spectral power of the cytosolic Ca2+ oscillator was reduced by magnetic field exposure and the effect increased in a dose-response manner. This reduction was also observed in the 0-10 mHz subinterval of the oscillation spectrum, while higher frequency subintervals showed no significant change.
Unknown authors · 1999
Researchers exposed human leukemia T-cells to 50 Hz magnetic fields (the same frequency as electrical power lines) and measured calcium oscillations inside the cells. They found that magnetic field exposure reduced these calcium signals in a dose-dependent manner - the stronger the field, the greater the reduction. This matters because calcium signaling is crucial for immune cell function and communication.
Linz et al. · 1999
Researchers tested the effects of radio frequency fields at 180, 900, and 1800 MHz on the electrical properties of isolated ventricular myocytes from guinea pigs and rats. The fields were applied using rectangular waveguides or a TEM cell at specific absorption rates up to 880 mW/kg, with 900 and 1800 MHz signals pulsed to the GSM standard. None of the tested electrophysiological parameters, including membrane potential, action potential, L-type calcium current, and potassium currents, were significantly changed by RF exposure. Lowering the temperature from 36°C to 24°C reduced current amplitude by almost 50% and shifted voltage dependence by about 5 mV, but RF exposure at the lower temperature still did not affect L-type calcium current.
Gandhi OP, Lazzi G, Tinniswood A, Yu QS, · 1999
Researchers compared numerical and experimental methods for determining SAR and radiation patterns of handheld wireless telephones at 835 and 1900 MHz. Peak 1-g SARs ranged from 0.13 to 5.41 W/kg, yet agreement between calculated and measured data was generally within plus or minus 20%. The study noted that for a maximum radiated power of 600 mW at 800/900 MHz, peak 1-g SARs can be higher than 1.6 W/kg unless antennas are carefully designed and placed further away from the head.
Unknown authors · 1999
Researchers exposed HBL-100 cells and normal human mammary epithelial cells to 60 Hz EMF at flux densities of 0.1, 1.0, and 10.0 Gauss for periods ranging from 20 min to 24 h. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields (the same frequency as household electricity) at various strengths for up to 24 hours to see if EMF exposure would alter cancer-related genes. The study found no significant changes in gene expression for key cancer markers like c-myc, p53, and others, suggesting 60 Hz magnetic fields don't promote breast cancer through genetic mechanisms.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields at various strengths (0.1 to 10 Gauss) for up to 24 hours to test whether power line frequencies could trigger cancer-related gene changes. The study found no significant effects on cancer-associated genes including c-myc, p53, and others, suggesting 60 Hz EMF is unlikely to promote breast cancer through direct gene expression changes.
Novoselova, EG, Fesenko, EE, Makar, VR, Sadovnikov, VB · 1999
Russian researchers exposed mice to very low-level microwave radiation (similar to what cell towers emit) for 5 hours and found it significantly boosted immune system activity. The microwaves increased production of tumor necrosis factor (TNF), a key immune signaling molecule, in immune cells called macrophages and T-cells. This immune activation lasted for at least 3 days after exposure and was enhanced when mice were given antioxidant nutrients.
Morrissey JJ et al. · 1999
Researchers investigated the effects of a one-hour exposure of mice to a 1.6-GHz radiofrequency signal, either continuous wave or pulse-modulated at 11 Hz (IRIDIUM), on c-fos gene expression in the brain. C-fos expression was not significantly elevated until exposure levels exceeded six times the peak dose and 30 times the whole-body average dose relative to human cellular telephone exposure limits. The pattern of c-fos elevation in limbic cortex and subcortex areas was consistent with a stress response due to thermal perception and restraint, not a direct interaction of IRIDIUM energy with brain tissue.
Trosic I, Matausicpisl M, Radalj Z, Prlic I, · 1999
The remaining 20 rats served as control. Exposed rats showed a decreasing tendency in total leukocyte and relative lymphocyte counts and a slight increase in granulocyte and erythrocyte counts.
Li et al. · 1999
Researchers exposed human fibroblast cells to 837 MHz continuous microwaves for 2 hours at SAR levels of 0.9 or 9.0 W/kg. TP53 protein levels were measured by Western blot at 2, 8, 24, and 48 hours after exposure. No significant changes in TP53 protein expression were found in exposed cells compared to sham or untreated cells at any time point. No morphological alterations were observed in microwave-treated cells compared to sham-treated cells.
Fesenko EE et al. · 1999
Researchers investigated how weak electromagnetic waves in the centimeter range affected the cytotoxic activity of natural killer cells in mice. Irradiation at 8.15 to 18 GHz at 1 microwatt per square centimeter increased the cytotoxic activity of natural killer cells of rat spleen. In mice exposed for 24 to 72 hours, natural killer cell activity increased by 130 to 150%, and this elevated activity persisted for 24 hours after exposure ended. Microwave irradiation of animals in vivo for 3.5 and 5 hours, and a short exposure of splenic cells in vitro, did not affect natural killer cell activity.
Fesenko EE et al. · 1999
Russian researchers exposed mice to weak microwave radiation (8.15-18 GHz) for 24-72 hours and found their natural killer cells - immune cells that fight cancer and infections - became 130-150% more active. The immune boost lasted at least 24 hours after exposure ended, but shorter exposures of just a few hours showed no effect.
Khadir R, Morgan JL, Murray JJ. · 1999
Researchers investigated the effects of a sinusoidal 60 Hz magnetic field on free radical production, degranulation, and viability in human neutrophils. Exposure of unstimulated human neutrophils to the magnetic field did not affect the functions examined. When cells were also stimulated with PMA, exposure to a 22 mT, 60 Hz magnetic field induced significant increases in superoxide anion production of 26.5% and in β-glucuronidase release of 53%. Release of lysozyme and lactate dehydrogenase was unchanged by the magnetic field, whether the cells were stimulated or not.
E.G Novoselova, E.E Fesenko, V.R Makar, V.B Sadovnikov · 1999
Researchers tested the effect of 8.15–18 GHz microwave radiation at a power density of 1 μW/cm2 on TNF production and immune response. A single 5-hour whole-body exposure induced a significant increase in TNF production in peritoneal macrophages and splenic T cells, and the mitogenic response in T lymphocytes also increased. The activation of cellular immunity was observed within 3 days after exposure. A diet containing β-carotene, α-tocopherol, and ubiquinone Q9 increased the activity of macrophages and T cells from irradiated mice.
Adey WR et al. · 1999
Researchers tested an 836.55 MHz NADC-modulated field in a 2-year bioassay with fetal exposure in Fischer 344 rats. Of 236 original rats, 182 (77%) survived to termination at age 709-712 days. There was no evidence of tumorigenic effects in the CNS from TDMA field exposure. Exposed animals showed trends toward reduced incidence of spontaneous CNS tumors (P < 0.16) and ENU-induced CNS tumors (P < 0.16). In preterm rats where neural tumors caused death, fields decreased ENU-induced tumor incidence (P < 0.03).
Jauchem JR, Frei MR, Ryan KL, Merritt JH, Murphy MR · 1999
The study investigated the lack of effects on heart rate and blood pressure in ketamine-anesthetized rats briefly exposed to ultra-wideband electromagnetic pulses. Exposures at a repetition frequency of 1 kHz for 0.5 s or to repetitive pulse trains for a total of 2 min resulted in no significant changes in heart rate or mean arterial blood pressure. These results suggest that acute whole-body exposure to UWB pulses does not have a detrimental effect on the cardiovascular system.
Unknown authors · 1999
Researchers conducted a population-based case-control study across England, Wales, and Scotland. They measured household and school magnetic fields for 2226 matched case-control pairs and estimated average exposure in the year before diagnosis. For children with mean exposures above 0.2 microT compared to below 0-1 microT, the adjusted odds ratio for all malignant disease combined was 0.87 (95% CI 0.56-1.35).
Unknown authors · 1999
Unknown authors · 1999
Unknown authors · 1999
Researchers evaluated the effect of a 60 Hz electromagnetic field on NF-kappaB or AP-1-dependent reporter gene expression in human U937 leukemia cells. Reporter genes were electroporated into the cells and pathway activation was measured by CAT protein using CAT ELISA. Magnetic field intensities of 0.08, 0.1, 1.0, and 1.3 mT had no effect on either signaling pathway.
Unknown authors · 1999
Researchers studied DNA migration using the comet assay in brain cells of CBA mice exposed continuously to 50 Hz, 0.5 mT magnetic fields for 2 hours, 5 days, or 14 days. No differences were observed in mice exposed for 2 hours or 5 days compared with controls. Mice exposed for 14 days showed significantly extended DNA migration (0.02 < p < 0.05).
