Paulraj R, Behari J · 2002
Researchers exposed 35-day-old Wistar rats to low-level continuous 2.45 GHz microwaves for 2 hr/day over 35 days at a power density of 0.34 mW/cm2 with a specific absorption rate of 0.1 W/kg. Exposed rats showed a significant increase in calcium ion efflux and ornithine decarboxylase activity and a significant decrease in calcium-dependent protein kinase activity in brain tissue. The authors suggested that the radiation affects membrane-bound enzymes linked to cell proliferation and differentiation, indicating a possible tumor-promoting role.
Natarajan M, Vijayalaxmi , Szilagyi M, Roldan FN, Meltz ML · 2002
Kolomytseva MP, Gapeev AB, Sadovnikov VB, Chemeris NK. · 2002
Di Carlo A, White N, Guo F, Garrett P, Litovitz T. · 2002
Chick embryos were exposed to ELF-EMFs at 8 microT continuously for 4 days, or to ELF or RF EMFs repeated daily for 4 days in sessions of 20, 30, or 60 minutes once or twice daily. Several exposure protocols produced statistically significant decreases in protection against hypoxic stress, including continuous ELF and 30 or 60 minute ELF twice daily, or 30 or 60 minute once daily RF. Following 4 days of ELF-EMF exposure, HSP70 levels declined by 27% compared to controls.
d'Ambrosio G, MassaR, Scarfi MR, Zeni O · 2002
Researchers exposed human peripheral blood cultures to 1.748 GHz microwaves, either as continuous wave or phase-only modulated wave, for 15 minutes. The study measured cell proliferation kinetics and micronucleus frequency to look for genotoxic effects. No changes in cell proliferation kinetics were found after either type of exposure. A statistically significant micronucleus effect was found following exposure to the phase modulated field, but not after continuous wave exposure. The researchers suggested these results indicate a genotoxic power of the phase modulation itself.
Cao XZ, Zhao ML, Wang DW, Dong B. · 2002
Researchers studied whether electromagnetic pulse (EMP) could induce apoptosis in a human lung carcinoma cell line called GLC-82. Cells were irradiated with EMP at an electric field intensity of 60 kV/m, 5 pulses per 2 minutes, and analyzed using cytometry, MTT chronometry, and flow cytometry. EMP visibly inhibited proliferation and activity of the GLC-82 cells, and the highest apoptosis rate reached 13.38% at 6 hours after irradiation. EMP also down-regulated bcl-2 expression and up-regulated p53 expression in the GLC-82 cells.
Bisht KS, Moros EG, Straube WL, Baty JD, Roti Roti JL · 2002
Researchers exposed C3H 10T½ cells to 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiofrequency radiation to determine whether it caused micronuclei to form. Cells were exposed at power levels of 3.2 or 4.8 W/kg for CDMA and 3.2 or 5.1 W/kg for FDMA, for durations of 3, 8, 16, or 24 hours. In three repeat experiments, no exposure condition produced a significant increase in micronuclei compared to sham-exposed cells.
Zhang MB, He JL, Jin LF, Lu DQ. · 2002
Researchers studied whether 2450-MHz microwave radiation interacts with the chemical mitomycin C (MMC) to produce genotoxic effects in human lymphocytes in vitro. Blood cells from a male donor and a female donor were exposed to 2450-MHz microwaves at 5.0 mW/cm2 for 2 h, to MMC alone for 24 h, or to MMC for 24 h following microwave exposure. Microwave exposure alone did not significantly increase comet lengths compared with controls, but combined microwave plus MMC exposure produced significantly longer comet lengths than MMC alone at doses of 0.025 microgram/mL or higher.
Akoev IG et al. · 2002
The study explored how the frequency of microwave modulation affected the activity of several enzymes and affective rat behavior at intensities of 0.8 to 10 microW/cm2. The researchers proposed that free radical processes may play a role in the nonlinear effects observed and in the modification of emotional behavior in animals. The study also postulated a protective role for monoaminoxidase, which is located on the outer surface of mitochondria and deaminates monoamines.
Liu Y, Weng E, Zhang Y, Hong R. · 2002
Researchers exposed mice to a 50 Hz sinusoidal electromagnetic field at 0.2 mT or 6.0 mT for 2 weeks, and measured markers of the antioxidant system and cell membrane fluidity in brain and liver tissue. Malondialdehyde content in brain and liver increased with exposure, while total antioxidant capability decreased at both field strengths. When electromagnetic field exposure was combined with lead, the researchers observed synergic effects on lipid peroxidation.
Jajte J, Grzegorczyk J, Zmyślony M, Rajkowska E. · 2002
Researchers exposed rat blood lymphocytes to a 7 mT static magnetic field for 3 hours in Helmholtz coils, with some samples also treated with ferrous chloride at 10 μg/ml. The static magnetic field alone and iron ions alone each produced no significant effect on cell viability. When the field and iron ions were combined, there was a significant increase in apoptotic and necrotic cells and significant alterations in cell viability. The researchers suggested that a 7 mT static magnetic field in the presence of Fe2+ ions can increase the concentration of oxygen free radicals and thus may lead to cell death.
Trosic I, Busljeta I, Kasuba V, Rozgaj R. · 2002
Researchers exposed adult male Wistar rats to continuous 2450 MHz radiofrequency microwave radiation for 2 hours a day, 7 days a week, for up to 30 days, at a power density of 5–10 mW/cm2. Peripheral blood smears were examined for micronuclei in polychromatic erythrocytes as an indicator of genotoxicity. Micronuclei per 1000 PCEs were significantly increased after eight irradiation treatments compared with sham-exposed controls. The researchers noted that an adaptive mechanism in both erythrocytopoiesis and genotoxicity likely appeared during the subchronic irradiation treatment.
Vijayalaxmi et al. · 2001
Eight adult male Sprague-Dawley rats were exposed to 2450 MHz RFR in circularly polarized waveguides, and eight sham-exposed rats were kept in similar waveguides without RFR transmission. Four rats treated with mitomycin-C served as positive controls, and all rats were necropsied 24h after exposure to examine peripheral blood and bone marrow smears for micronuclei in polychromatic erythrocytes. The incidence of micronuclei per 2000 polychromatic erythrocytes was not significantly different between RFR-exposed and sham-exposed rats.
Vijayalaxmi et al. · 2001
Researchers exposed peripheral blood samples from four healthy nonsmoking volunteers to 847.74 MHz CDMA radiation at SARs of 4.9 or 5.5 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.5 Gy) samples served as controls. No significant differences were found between RF-exposed and sham-exposed lymphocytes in mitotic indices, frequencies of exchange aberrations, excess fragments, binucleate cells, or micronuclei. Gamma-irradiated lymphocytes showed significantly different responses for all indices compared to both RF-exposed and sham-exposed cells. The authors concluded there was no evidence for induction of chromosome aberrations and micronuclei under these exposure conditions.
Vijayalaxmi et al. · 2001
Researchers exposed diluted peripheral blood from four healthy volunteers to 835.62 MHz RF radiation at SARs of 4.4 or 5.0 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.50 Gy) samples served as negative and positive controls, and lymphocytes were cultured for 48 or 72 hours to assess chromosomal aberrations, micronuclei, mitotic indices, and binucleate cells. No significant differences were found between RF-exposed and sham-exposed lymphocytes for any of the measured endpoints, while gamma radiation produced significantly different responses. The authors concluded there is no evidence for induction of chromosomal aberrations and micronuclei under these exposure conditions.
Roti Roti JL et al. · 2001
Researchers measured the effect of 835.62 MHz FDMA and 847.74 MHz CDMA radiation on neoplastic transformation frequency using the in vitro C3H 10T(1/2) cell transformation assay system. Cells were exposed at 37°C to either radiation at a specific absorption rate of 0.6 W/kg for 7 days to test for genotoxic effects, or after 4.5 Gy X-ray exposure for 42 days to test for epigenetic promotion effects. After both the 7-day and 42-day exposures, no statistically significant differences in transformation frequencies were found between incubator controls, sham-exposed groups, and RF-exposed groups.
Maes A, Collier M, Verschaeve L · 2001
Researchers investigated cytogenetic effects of 900 MHz radiofrequency fields using chromosome aberration and sister chromatid exchange frequency methods. They studied three exposure modes (continuous, pseudo-random, dummy burst) at power outputs from 0 to 50 W. Specific absorption rates ranged from 0 to 10 W/kg. The study examined effects of radiation alone and combined with mitomycin C and X-rays. Overall, no mutagenic or co-mutagenic effect was found.
Higashikubo R et al. · 2001
Researchers exposed mouse C3H 10T(1/2) fibroblasts and human U87MG glioma cells to two types of radiofrequency fields at 0.6 W/kg. Five cell cycle parameters including transit through G1, G2, and S phase and probability of cell division were measured immediately and up to 100 hours. No changes in cell cycle parameters were observed in exposed cells compared to sham-exposed cells in either cell line during the entire experimental period.
Li L et al. · 2001
Researchers exposed murine C3H 10T(1/2) fibroblasts to radiofrequency fields at specific absorption rates of 3.2 to 5.1 W/kg. Cell cultures were exposed to 847.74 MHz CDMA and 835.62 MHz FDMA modulated radiations in radial transmission line irradiators with temperature regulated to 37.0 ± 0.3 °C. Using the alkaline comet assay, they found no statistically significant differences in comet moment or comet length between sham-exposed and exposed cells after 2, 4, or 24 hours of exposure, for both exponentially growing and plateau-phase cells. A 4-hour incubation after a 2-hour exposure also resulted in no significant changes in comet moment or comet length. The authors concluded that exposure at 37°C up to 5.1 W/kg did not induce measurable DNA damage.
Sebastian JL, Munoz S, Sancho M, Miranda JM · 2001
Researchers calculated electric field intensity using the finite element method in single- and multilayer spherical, cylindrical, and ellipsoidal mammalian cell models exposed to 900 and 2450 MHz plane waves. They analyzed how cell geometry and orientation relative to the external field influence the electric field induced in the membrane and cytoplasm. The study found that cytoplasmic and extracellular bound water layers play a significant role in determining electric field intensity for cylindrical and ellipsoidal models.
Peyman A, Rezazadeh AA, Gabriel C · 2001
Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.
Lalic H, Lekic A, Radosevic-Stasic B. · 2001
Researchers investigated genotoxic effects of occupational exposure to ionizing and non-ionizing radiation in 25 hospital workers and 20 radio-relay station workers using chromosome aberration analysis of peripheral blood lymphocytes. Total chromosome aberrations were almost equally higher in both exposed groups compared to unexposed controls. Acentric fragments were the most frequent aberration and were significantly higher in both exposed groups than in controls. Dicentric fragments were also elevated in both exposed groups, while chromatid breaks increased only after ionizing radiation.
Devyatkov ND, Pletnyov SD, Betskii OV, Faikin VV · 2001
The article presents experimental investigations of the inhibitory effect of low-energy and high-peak-power nanosecond microwave pulses on malignant tumor growth. The authors concluded that these microwave pulses can serve as a promising means for treating malignant diseases.
Cheever KL et al. · 2001
Researchers exposed pregnant rats to 10 MHz radiofrequency radiation and measured metabolism and distribution of 2-methoxyethanol and its metabolite methoxyacetic acid. Radiofrequency exposure reduced total body clearance of radiolabeled 2-methoxyethanol but did not change methoxyacetic acid levels in serum, embryos, or extraembryonic fluid. Protein adduct formation in embryos did not differ in a way that would explain the reported synergy between radiofrequency radiation and 2-methoxyethanol.
Moustafa YM, Moustafa RM, Belacy A, Abou-El-Ela SH, Ali FM. · 2001
Researchers investigated the effect of acute exposure to radiofrequency fields from commercially available cellular phones on oxidative stress parameters in 12 healthy adult male volunteers. Each volunteer placed the phone in his pocket in standby position with the keypad facing the body. The parameters measured were lipid peroxide and the activities of superoxide dismutase (SOD), total glutathione peroxidase (GSH-Px) and catalase. Plasma lipid peroxide increased significantly after 1, 2, and 4 hours of exposure. SOD and GSH-Px activities in erythrocytes showed significant reduction, while catalase activity did not decrease significantly.
