Wang J et al. · 2006
Researchers exposed A172 cells to 2450 MHz high-frequency electromagnetic fields at SARs of 5-200 W/kg and included heat controls at 38-44°C. HSP70 expression increased in a time- and dose-dependent manner at SARs above 50 W/kg for 1-3 hours, similar to heat controls. HSP27 expression did not change significantly with HFEMF exposure or heating, but HSP27 phosphorylation increased transiently at 100 and 200 W/kg, exceeding the effect of heating at 40-44°C, peaking after 1 hour at 100 W/kg.
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.
Pavicic I, Trosic I, Sarolic A · 2006
Researchers compared the effects of 864 MHz and 935 MHz microwave radiation on V79 cell proliferation, colony formation, and viability. Cells exposed to 864 MHz for 2 or 3 hours showed significantly reduced growth on day 3, whereas 3-hour 935 MHz exposure significantly increased growth. Colony-forming ability and viability did not differ significantly from controls for either frequency.
Yurekli AI et al. · 2006
Researchers used a gigahertz transverse electromagnetic (GTEM) cell to expose rats to electromagnetic fields at the GSM base transceiver station frequency of 945 MHz. The power density applied was 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which the researchers described as well below current exposure limits. MDA levels increased and GSH concentrations decreased significantly (p < 0.0001) under this exposure. There was also a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.
De Nicola M et al. · 2006
Researchers exposed U937 cells to static magnetic fields at 6 mT and found a strong increase of reactive oxygen species and a decrease of glutathione levels after 2 hours of exposure. Extremely-low-frequency magnetic fields also affected intracellular glutathione, starting from a threshold at 0.09 mT. ELF magnetic fields protected U937 from apoptosis, but this ability was limited to the ELF intensities able to alter redox equilibrium. When the cells' redox state was artificially altered, magnetic fields failed to affect apoptosis, suggesting a correct intracellular redox state is required for the antiapoptotic effect.
Wolf FI et al. · 2005
Researchers exposed HL-60 leukemia cells, Rat-1 fibroblasts, and WI-38 diploid fibroblasts to 0.5-1.0 mT 50-Hz ELF-EMF for 24-72 hours. The treatment caused a dose-dependent increase in proliferation rate, about 30% after 72 hours at 1.0 mT. DNA damage increased dose-dependently with peaks at 24 and 72 hours. Pretreatment with the antioxidant alpha-tocopherol prevented both the proliferation increase and DNA damage, implicating redox mechanisms.
Unknown authors · 2005
Researchers analyzed the effect of a clinically useful pulsed electromagnetic field on MG-63 human osteoblast-like cells. The cells were grown in medium with 0.5% or 10% fetal calf serum. PEMF increased thymidine incorporation and decreased putrescine, while spermidine and spermine were not significantly affected. c-myc was activated after 1 hour and then downregulated, while c-fos mRNA increased after 0.5 hour and then decreased.
Unknown authors · 2005
Unknown authors · 2005
The study found that human lymphocyte-synthesized melatonin plays a crucial role in modulating the IL-2/IL-2 receptor system. When melatonin biosynthesis was blocked with parachlorophenylalanine, both IL-2 and IL-2 receptor levels fell, and adding exogenous melatonin restored them. The effects were mediated by melatonin receptors, as antagonists luzindole and CGP 55644 significantly decreased IL-2 and IL-2 receptor expressions. Blocking membrane receptors with luzindole increased prostaglandin E2-induced inhibition of IL-2 production.
Unknown authors · 2005
Researchers exposed cultured cells from different tissues to intermittent 50 Hz, 1 mT ELF-EMF for 1-24 hours. They used alkaline and neutral comet assays to assess ELF-EMF-induced DNA strand breaks. The study identified three responder cell types (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells).
Unknown authors · 2005
Researchers exposed cultured human fibroblasts to intermittent 50 Hz ELF-EMF (5 minutes on, 10 minutes off) at 1 mT for 2 to 24 hours. Micronuclei frequency increased in a time-dependent manner, becoming statistically significant after 10 hours and plateauing at roughly three times the basal level after about 15 hours. Chromosomal aberrations were also elevated, reaching up to 10-fold above baseline.
Unknown authors · 2005
Researchers exposed two clones of MCF-7 breast cancer cells to 50Hz electromagnetic fields and calculated IC(50) values from tamoxifen dose-response curves. The dose-response curves shifted to higher tamoxifen concentrations in an intensity-dependent manner, with a maximal response at 1.2muT. The authors hypothesized that electromagnetic field exposure could contribute to tamoxifen resistance observed in breast cancer after long-term treatment.
Unknown authors · 2005
Researchers exposed insulin solution to a pulsed electric field of 0.7 V/m at 50 Hz for 20 minutes and then added it to human hepatocyte cultures. They investigated insulin signaling events including ligand-receptor binding, tyrosine phosphorylation, gene transcription, and cell proliferation using multiple methods. PEF exposure caused a conformational change in insulin, reduced its receptor binding capacity to 87% of control, and decreased intracellular tyrosine phosphorylation by 11%. The expression of 55 out of 12000 genes was altered, including increased expression of human tyrosine phosphatase and a small GTP-binding protein.
Unknown authors · 2005
The study used molecular dynamics simulations to examine insulin chain-B under static and oscillating electric fields ranging from 10(7) to 10(9) V/m. Both field types affected the protein's normal behavior, with oscillating fields being more disruptive to structure than static fields of similar strength. Static fields stabilized the secondary structure but restricted the inherent flexibility required for insulin's biological activity.
Swanson J et al et al. · 2005
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.
Franke H et al. · 2005
Researchers investigated the influence of a generic UMTS signal on barrier tightness, transport processes, and morphology of porcine brain microvascular endothelial cell cultures serving as an in vitro blood-brain barrier model. The cells were exposed continuously for up to 84 hours at an average electric-field strength of 3.4-34 V/m with a maximum of 1.8 W/kg under athermal conditions. Barrier tightness measured by 14C-sucrose and serum albumin permeation and by transendothelial electrical resistance remained unchanged compared to sham-exposed cultures. Permeation of transporter substrates and the localization and integrity of the tight-junction proteins occludin and ZO1 were also unaffected.
Chang SK et al. · 2005
Researchers examined the biological effects of an 835-MHz EMF on bacterial reverse mutation (Ames assay) and DNA stability (in vitro DNA degradation) using tester strains exposed to a continuous waveform at a specific absorption rate (SAR) of 4 W/kg for 48 h. In the presence of the EMF, some strains showed increased mutation rates with certain mutagens while others showed antimutagenic effects, but these effects were not significantly repeated in other relevant strains. Exposure to 835-MHz EMF did not change the rate of DNA degradation measured using plasmid pBluescript SK(+) as an indicator. The researchers concluded that 835-MHz EMF under the study conditions neither affected reverse mutation frequency nor accelerated DNA degradation in vitro.
McEvoy SP et al. · 2005
Driver mobile phone use up to 10 minutes before a crash was associated with a fourfold increased likelihood of crashing (odds ratio 4.1, 95% CI 2.2 to 7.7). Risk was raised irrespective of whether a hands-free device was used, with hands-free odds ratio 3.8 and hand-held odds ratio 4.9. Increased risk was similar in men and women and in drivers aged 30 years or older and younger than 30 years. A third of calls before crashes and on trips during the previous week were reportedly on hand-held phones (n = 21).
Musaev AV, Ismailova LF, Gadzhiev AM. · 2005
Researchers studied changes in ascorbate- and NADPN2-dependent induced lipid peroxidation in the visual analyzer and hypothalamus of 3- and 12-month-old rats exposed to high- and low-intensity microwaves. High-intensity exposure stimulated basal LPO but suppressed LPO-inducing systems. Low-intensity exposure activated induced LPO systems accompanied by synchronous antioxidant defense activity maintaining redox balance. The authors concluded that microwaves can be either beneficial or a factor of oxidative stress depending on intensity.
Hunton J, Rose JM. · 2005
The study used an experiment where drivers with and without communication training completed a simulated driving course under three conversation conditions. Cellular telephone conversations consumed more attention and interfered more with driving than passenger conversations. Cell phone conversations lack nonverbal cues available in close-contact conversations, leading participants to expend significant cognitive resources to compensate. Communication training may reduce the hazardous effects of cell phone conversations on driving performance.
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.
Gandhi G, Anita · 2005
Researchers investigated DNA and chromosomal damage in peripheral blood lymphocytes of 24 mobile phone users exposed to microwave frequencies of 800-2000 MHz. DNA damage measured by comet assay showed a mean comet tail length of 26.76 ± 0.054 mm with 39.75% of cells damaged, which was highly significant compared to controls. The in vivo capillary blood micronucleus test also revealed a highly significant frequency of micronucleated cells at 0.25.
Morimoto S et al. · 2005
The study examined how EMF radiation affects endothelin-1 production by cultured endothelial cells. EMF radiation reduced basal ET-1 levels in human umbilical vein and microvascular endothelial cells but did not reduce them in bovine and human aortic endothelial cells. EMF radiation significantly inhibited thrombin-stimulated ET-1 production and mRNA expression in all four cell types in a dose-dependent manner. The inhibition was abolished by the nitric oxide synthase inhibitor NG-monomethyl-L-arginine at 10−3 mol/l.
Tkalec M, Malaric K, Pevalek-Kozlina B. · 2005
Researchers evaluated duckweed growth and peroxidase activity after exposure in a Gigahertz Transversal Electromagnetic (GTEM) cell to electric fields at frequencies of 400, 900, and 1900 MHz. Plants exposed for 2 h to a 23 V/m field at 900 MHz showed significantly decreased growth compared with the control, while the same field strength at 400 MHz did not have such an effect. Peroxidase activity in exposed plants varied depending on exposure characteristics, with a significant increase of 41% found in plants exposed for 2 h to 41 V/m at 900 MHz.
