Dabrowski MP et al. · 2003
Researchers exposed cultured human blood mononuclear cells isolated from 16 healthy donors to 1300 MHz pulse-modulated microwaves at a power density of 10 W/m2 and a SAR of 0.18 W/kg. Lymphocyte proliferative responses and IL-2 receptor saturation did not change, though lymphocyte production of IL-10 increased (P < .001). Monocyte production of IL-1β increased significantly (P < .01), the concentration of its antagonist IL-1ra dropped by half (P < .01), and TNF-α remained unchanged. The researchers concluded that pulse-modulated microwaves represent the potential of immunotropic influence, stimulating preferentially the immunogenic and proinflammatory activity of monocytes at relatively low levels of 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.
Mashevich M et al. · 2003
Researchers examined whether in vitro exposure of human peripheral blood lymphocytes to continuous 830 MHz electromagnetic fields causes losses and gains of chromosomes, a condition called aneuploidy. Cells were irradiated at SAR levels ranging from 1.6 to 8.8 W/kg for 72 hours. A linear increase in chromosome 17 aneuploidy was observed as a function of the SAR value, which the researchers described as a genotoxic effect. Control experiments conducted without any RF radiation across a temperature range of 34.5 to 38.5 °C showed that elevated temperature was not associated with the increased aneuploidy or the changes in centromeric DNA replication seen after RF exposure.
Unknown authors · 2002
EMF exposure increased sulfate incorporation, glycosaminoglycan content, chondrocyte number at day 8, cartilage volumetric density, and immunostaining for antibodies 3B3 and 5D4. DNA content and thymidine incorporation did not differ between groups, indicating no increase in cell proliferation. Proteoglycan and glycosaminoglycan molecular sizes and composition were unchanged, showing accelerated synthesis of normal cartilage molecules. Expression of proteoglycan and type II collagen mRNA increased, along with greater immunoreactivity for 3B3 and 504, suggesting faster chondrocyte differentiation and phenotypic maturation.
Unknown authors · 2002
However, research reports indicate that living cells may respond to power-frequency fields well below the thermal noise limits. The study proposes that published thermal arguments may not fully account for all membrane force fields of thermal origin, and that a full accounting could show smaller net thermal noise fields in the power-frequency range.
Shckorbatov YG et al. · 2002
Researchers used intracellular microelectrophoresis to study electrokinetic properties of nuclei in human buccal epithelial cells after microwave exposure at wavelengths of 8 mm and 16 mm with a surface power density of 0.2 mW/cm(2). Microwave irradiation for 15-60 s induced ENN changes, decreasing ENN when it was initially elevated and increasing it when initially low. No significant difference between the action of microwaves of wavelengths of 8 mm and 16 mm was found. Microwave exposure increased membrane permeability for the in vivo dye indigo Carmine in cells from all donors regardless of initial ENN levels.
Pakhomov AG, Gaj ek P, Allen L, Stuck BE, Murphy MR · 2002
Researchers compared bioeffects of continuous wave and extremely high power pulse microwaves at 9.3 GHz and 1.25 W average power using yeast cell density in agarose gel. Cell density was strongly affected by irradiation and correlated with local temperature rise, but no statistically significant difference between CW and EHPP was found across the SAR range. A trend (P<0.1) for a difference appeared at average SAR of 100 W/kg and higher, corresponding to peak SAR above 20 MW/kg for EHPP.
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.
McNamee JP et al. · 2002
Blood cultures from human volunteers were exposed to an acute 1.9 GHz pulse-modulated radiofrequency (RF) field for 2 h using a series of six circularly polarized, cylindrical waveguides. Mean specific absorption rates (SARs) ranged from 0 to 10 W/kg and the temperature within the cultures during the exposure was maintained at 37.0 ± 0.5°C. DNA damage was quantified in leukocytes by the alkaline comet assay and the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected by the comet assay and no significant differences in micronucleus frequency were found at any SAR tested.
McNamee JP et al. · 2002
Human blood cultures were exposed to a 1.9 GHz continuous-wave radiofrequency field for 2 hours at SARs of 0.0, 0.1, 0.26, 0.92, 2.4, and 10 W/kg while temperature was maintained at 37.0 ± 0.5°C. DNA damage was measured immediately after exposure using the alkaline comet assay with four parameters, and micronucleus formation was assessed using the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected at any SAR tested. There was no significant difference in micronucleus incidence between exposed cultures and sham controls at any SAR.
Tafforeau M et al. · 2002
Researchers exposed flax seedlings to a 1-minute cold shock or a 2-hour GSM telephone radiation at 0.9 GHz and observed epidermal meristem production. They performed a SIMS analysis of inorganic cations in hypocotyl tissue from control and calcium-deprived seedlings. The analysis revealed decreases in calcium, sodium, and potassium and an increase in magnesium without substantially changing the divalent-to-monovalent cation ratio.
Stopczyk D et al. · 2002
Researchers assessed the effect of mobile phone electromagnetic fields on SOD-1 activity and MDA level in human blood platelets exposed to 900 MHz for 1, 3, 5, and 7 minutes. SOD-1 activity was significantly depleted after 1, 5, and 7 minutes of exposure and increased after 3 minutes compared with controls. MDA concentration increased significantly after 1, 5, and 7 minutes and decreased after 3 minutes compared with controls. The authors concluded that oxidative stress from microwave exposure may cause adverse cellular changes and systemic disturbances.
Shallom JM et al. · 2002
Researchers exposed chick embryos to athermal 915 MHz microwave radiation to test for induction of the stress protein Hsp70. Hsp70 levels increased within 2 hours, reaching a maximum about 30% above controls by 3 hours. Embryos pre-exposed to microwave radiation before hypoxic stress had significantly higher survival after re-oxygenation than non-exposed controls (P < 0.05).
Pologea-Moraru R, Kovacs E, Iliescu KR, Calota V, Sajin G · 2002
Researchers studied the effects of low-power microwaves at 2.45 GHz on the membrane fluidity of rod photoreceptor cells. The researchers expected the retina to be very sensitive to microwave irradiation due to the polar character of photoreceptor cells and high water content.
Pacini S et al. · 2002
Researchers exposed human skin fibroblasts to GSM cellular phone radiofrequency for 1 hour. GSM exposure induced alterations in cell morphology and increased expression of mitogenic signal transduction genes, cell growth inhibitors, and apoptosis-related genes. A significant increase in DNA synthesis and intracellular mitogenic second messenger formation corresponded with high expression of MAP kinase family genes.
Liu X, Shen H, Shi Y, Chen J, Chen Y, Ji A. · 2002
Leszczynski D, Joenväärä S, Reivinen J, Kuokka R · 2002
Researchers exposed human endothelial EA.hy926 cells to 900 MHz GSM mobile phone radiation for 1-hour and observed changes in phosphorylation of many proteins. The exposure transiently increased phosphorylation of hsp27 and altered expression levels of hsp27 and p38MAPK, and this phosphorylation increase was prevented by a p38MAPK inhibitor. The culture temperature remained at 37 +/- 0.3 degrees C throughout the exposure, confirming non-thermal effects. The authors hypothesized that mobile phone radiation-induced activation of hsp27 may facilitate brain cancer by inhibiting the cytochrome c/caspase-3 apoptotic pathway and increase blood-brain barrier permeability by stabilizing endothelial cell stress fibers.
Higuchi Y et al. · 2002
Researchers performed a left-sided hemilaminectomy in adult Sprague-Dawley rats to expose the C6 dorsal root ganglion. Rats received pulsed radiofrequency, continuous radiofrequency, or sham treatment with the electrode on the ganglion for 120 seconds. Pulsed radiofrequency significantly increased cFOS-immunoreactive neurons in the superficial dorsal horn laminae three hours after treatment, while continuous radiofrequency did not. The authors concluded that pulsed radiofrequency activates pain-processing neurons in the dorsal horn without tissue heating.
de Pomerai DI, Dawe A, DjerbibL, Allan, Brunt G, Daniells C. · 2002
Researchers investigated growth rate and maturation proportion in C. elegans exposed to prolonged microwave fields at 25°C in synchronized cultures of wild-type larvae. Microwave exposure significantly increased growth rate by 8–11% and maturation proportion by 28–40%. Mild heat treatment at 28°C decreased growth rate by 10% and almost abolished maturation proportion, showing effects opposite to microwave exposure.
Beason RC, Semm P. · 2002
Researchers investigated the effects of a pulsed 900 MHz signal modulated at 217 Hz on avian brain neurons. The stimulation changed neural activity in more than half of the brain cells. 76% of responding cells increased their firing rates by an average of 3.5-fold. The remaining responding cells decreased their spontaneous activity rates. The authors suggested these responses indicate potential effects on humans using hand-held cellular phones.
Irmak MK et al. · 2002
Researchers investigated the influence of electromagnetic radiation from a digital GSM mobile telephone at 900 MHz on oxidant and antioxidant levels in rabbits. They measured adenosine deaminase, xanthine oxidase, catalase, myeloperoxidase, superoxide dismutase, glutathione peroxidase activities, nitric oxide, and malondialdehyde levels in sera and brains of exposed and sham-exposed rabbits. Serum SOD activity increased and serum NO levels decreased in exposed rabbits compared to sham-exposed rabbits, while other parameters did not change.
Ye J, Yao K, Zeng Q, Lu D. · 2002
Rabbits' eyes were exposed to 5 mW/cm(2) and 10 mW/cm(2) power densities of microwave radiation for 3 hours. The fluorescence-recovery-after-photobleaching (FRAP) method was used to determine gap junctional intercellular communication, and laser scanning confocal microscopy detected connexin 43 localization and function. Gap junctional intercellular communication was inhibited by microwave radiation, especially in the 10 mW/cm(2) irradiated samples. A decrease in connexin 43-positive staining was seen in 5 mW/cm(2) x 3 h treated LECs, and intracellular space accumulation and cytoplasmic internalization were clearly demonstrated in the 10 mW/cm(2) group.
Tice RR, Hook GG, Donner M, McRee DI, Guy AW. · 2002
DNA damage in leukocytes was assessed with the alkaline comet assay and chromosomal damage in lymphocytes with the micronucleus assay. No significant increase in DNA damage was seen after 3 or 24 hours, and no increase in micronucleated lymphocytes occurred after 3 hours. However, 24-hour exposures at 5.0 or 10.0 W/kg significantly increased micronucleated lymphocytes about fourfold, regardless of signal type, modulation, or frequency.
Testylier G, Tonduli L, Malabiau R, Debouzy JC · 2002
Rats were exposed to 2.45 GHz continuous wave at 2 or 4 mW/cm(2) for 1 h during the day, or to 800 MHz modulated at 32 Hz at 200 mW/cm(2) for 1 or 14 h during the night. Exposure at 4 mW/cm(2) caused a significant 40% decrease in mean acetylcholine release from hippocampus, maximal at 5 h post exposure. Fourteen-hour nighttime exposure at 800 MHz induced a significant 43% decrease in acetylcholine release during 11 p.m.-4 a.m. compared to control rats.
