Gao XF et al. · 2009
Researchers established a model of primary cultured Sertoli cells in vitro and exposed them to microwave radiation at average power densities of 0, 30, and 100 mW/cm(2) for five minutes. Cell cycle distribution shifted at exposure to 30 mW/cm(2) compared with the control groups, but the changes of rate of apoptosis and death and intracellular Ca2+ concentration showed no difference at 6 h after exposure. At 6 h after exposure to 100 mW/cm(2) microwave, there was a significant increase in intracellular Ca2+ concentration and rate of apoptosis and death, and the researchers identified the increase of intracellular Ca2+ concentration as one of the injury mechanisms.
Sharma VP, Singh HP, Kohli RK, Batish DR. · 2009
Researchers exposed mung bean (Vigna radiata) seeds to cell phone EMF radiation at a power density of 8.55 microW cm(-2) in the 900 MHz band for durations of 1/2, 1, 2, and 4 hours. Cell phone EMF radiation significantly inhibited germination at exposures of 2 hours or more, and inhibited radicle and plumule growth at 1 hour or more, in a time-dependent manner. The radiation enhanced MDA content, increased hydrogen peroxide accumulation, and raised root oxidizability, indicating oxidative stress and cellular damage. The study concluded that cell phone EMF radiation inhibits root growth by inducing oxidative stress despite increased activities of antioxidant enzymes.
Curcio G et al. · 2009
Researchers used functional near-infrared spectroscopy (fNIRS) to measure frontal cortex oxygenation in eleven healthy volunteers during a 40-minute exposure to a GSM mobile phone signal. The study found a slight linear increase in deoxygenated hemoglobin over time during real exposure, but no other measure showed GSM exposure-dependent changes. The researchers noted that their results should be confirmed on a larger sample size and using a multichannel instrument that allows the investigation of a wider portion of the frontal cortex.
Unknown authors · 2008
Researchers investigated the effects of 50 Hz magnetic fields on DNA damage response in murine L929 cells. Cells were exposed to magnetic fields at 100 or 300 microT combined with menadione or UVB radiation using various exposure schedules. Pre-exposure to 100 microT magnetic fields for 24 hours before menadione treatment decreased the proportion of sub G1 cells and increased the proportion of cells in G2/M phase. Exposure to 300 microT magnetic fields also decreased the proportion of cells in G1 phase. Magnetic field exposure after menadione treatment did not alter the response, and no effects were seen from magnetic fields alone or combined with UVB radiation.
Unknown authors · 2008
Researchers exposed cultured human lens epithelial cells to 0.4 mT 50 Hz magnetic fields for 2, 6, 12, 24, and 48 hours. After exposure, cells were fixed with 4% paraformaldehyde and stained for gamma H2AX immunofluorescence, and foci were counted in at least 200 cells per sample. Cells with more than three foci per cell were classified as positive, and mean foci per cell and percentage of positive cells were used as indexes of DNA double-strand breaks. Exposure for 24 hours significantly increased mean foci per cell to 2.93 and positive cells to 27.88% compared with sham (1.77 and 19.38%, P<0.05), and exposure for 48 hours increased them to 3.14 and 31.00% (P<0.01), while 2, 6, and 12 hour exposures showed no significant difference (P>0.05).
Unknown authors · 2008
Researchers exposed the human keratinocyte cell line HaCaT to 1 mT, 50 Hz ELF-EMF for different lengths of time and compared them with unexposed control cells. Cell growth and viability were evaluated by cell count and trypan blue exclusion. Significantly increased growth rates were observed after 48 hours of EMF exposure compared with control cells, while no difference in cell viabilities was detected. Gene expression and release of RANTES, MCP-1, MIP-1 alpha and IL-8 were significantly reduced after 72 hours of exposure. NF-kappaB levels became almost undetectable after only 1 hour of EMF exposure and were inversely correlated with cell density.
Unknown authors · 2008
Researchers exposed mouse osteoblast-like MC3T3-E1 cells to ELF-EMF at 3 mT and 60 Hz and measured cellular collagen as a marker of differentiation. ELF-EMF exposure significantly increased collagen content in the cells. Inhibiting the p38 MAPK pathway with SB203580 suppressed the ELF-EMF-induced collagen increase, while inhibiting the PI3K pathway with LY294002 accelerated it. The ERK1/2 inhibitor PD98059 reduced collagen in all conditions but did not block the ELF-EMF effect.
Unknown authors · 2008
Researchers evaluated the hormetic effect of non-thermal repetitive electromagnetic field shock (50MHz/0.5W) on primary human T lymphocytes and fibroblast cell lines. REMFS extended the total number of population doublings of mouse fibroblasts and contributed to youthful morphology of cells near their replicative lifespan. REMFS also enhanced cellular defenses of human T cells as reflected in lower cell mortality when compared to non-treated T cells. Mechanistic analysis showed that REMFS increased HSF1 phosphorylation, enhanced HSF1-DNA binding, and improved Hsp70 expression relative to non-REMFS-treated cells.
Unknown authors · 2008
Researchers tested whether alternating magnetic fields could induce DNA and chromosomal damage in primary human fibroblasts using comet and gammaH2AX assays. Cells were exposed to switching fields of 5 minutes on and 10 minutes off for 15 hours at intensities from 50 to 1000 microtesla using two different exposure systems. No DNA damage or chromosomal damage was detected with either exposure system. The study could not confirm previous reports of significant genotoxic effects from similar magnetic field parameters.
Unknown authors · 2008
Researchers exposed human lens epithelial cells intermittently for 24 hours to radiofrequency fields at specific absorption rates of 1, 2, 3, and 4 W/kg. DNA damage measured by alkaline comet assay increased significantly at 3 and 4 W/kg, while double-strand breaks increased only at 4 W/kg. Intracellular reactive oxygen species levels rose significantly at 3 and 4 W/kg, and cells exposed to 4 W/kg showed G0/G1 cell cycle arrest. Apoptosis did not differ between exposed and sham groups, and all observed effects were blocked when the radiofrequency field was superposed with 2 muT electromagnetic noise.
Unknown authors · 2008
Researchers present a model of slow non-uniform rotation of the charged nucleoid for combined effects of microwaves and static magnetic field. The model suggests that combined action results in slow non-uniform rotation of the nucleoid with angular speed depending on Larmor frequency. The model also predicts that non-thermal effects of microwaves depend on carrier frequency and static magnetic field in the exposure area.
Unknown authors · 2008
Researchers exposed V79 cells to 935 MHz continuous wave UHF radiation at 8.2 V/cm and 0.12 W/kg SAR for 1, 2, and 3 hours. Microtubule structure was assessed by immunocytochemistry and cell growth was measured by cell counts over five post-exposure days. Microtubule structure was clearly altered after 3 hours of exposure compared to controls (p<0.05). Cell growth was significantly decreased in cells exposed for 3 hours, measured three days after irradiation (p<0.05).
Unknown authors · 2008
Researchers exposed murine L929 fibroblasts to 872 MHz continuous wave or pulse modulated RF radiation at 5 W/kg. They measured ornithine decarboxylase activity after 1- and 24-hour exposures, proliferation during 48 hours after 24-hour exposure, and caspase-3 activity after 1-hour exposure. The cells responded to fresh medium and serum deprivation, but no consistent effects of RF radiation were found. One statistically significant difference in ODC activity (p=0.03) was observed but considered a chance finding due to multiple comparisons and lack of support from other data. The results did not support effects on the endpoints studied, and stressed or stimulated cells were not more sensitive than normal cells to RF radiation.
Moisescu MG, Leveque P, Bertrand JR, Kovacs E, Mir LM · 2008
Researchers designed a device for continuous microscopic observation of cells exposed to modulated EMF similar to mobile phone signals. The system allowed follow-up of cell progression into mitosis under controlled temperature and CO2 environment. Cells exposed to 900 MHz modulated EMF for 1 hour at 30 degrees C and 2.2 W/kg showed increased endocytosis rate but no alteration in mitosis progression or duration. The exposure system was validated by cell endocytosis measurements.
Yadav AS, Sharma MK. · 2008
Researchers studied 109 subjects, 85 regular mobile phone users and 24 non-users, collecting exfoliated buccal cells and screening 1000 cells per person for nuclear anomalies. Exposed users averaged 61.26 minutes daily and 2.35 years of use, and had significantly higher micronucleated cell counts than controls. Karyorrhexis, broken egg, and binucleated cell frequencies were slightly higher in exposed subjects but not statistically significant.
Inoue S, Motoda H, Koike Y, Kawamura K, Hiragami F, Kano Y. · 2008
Exposure to 2.45 GHz microwave irradiation at 200 W increased neurite outgrowth frequency about 10-fold compared to non-irradiated controls. The increase was prevented by adding a p38 MAPK inhibitor. Microwave treatment did not cause toxicity, unlike heat shock at 45°C.
Engelmann JC et al. · 2008
Researchers exposed Arabidopsis thaliana cell suspension cultures to a radiofrequency field protocol representing typical urban microwave exposure for 24 hours. They used Affymetrix-ATH1 whole genome microarrays to measure gene expression. Differential expression analysis revealed significant changes in transcription of 10 genes, but fold changes did not exceed 2.5. Three of the affected genes are dark-inducible, and their functions do not point to known plant responses to environmental stimuli.
Batellier F, Couty I, Picard D, Brillard JP. · 2008
Researchers exposed fertile chicken eggs to a cell phone in call position over the entire incubation period. Embryo mortality was significantly higher in exposed eggs than in sham eggs in two of four replicates. The additional mortality occurred mainly between days 9 and 12, but a causal relationship with electric field intensity could not be established.
Kim JY et al. · 2008
The study investigated clastogenicity of 835-MHz RF-EMF using alkaline comet assay and chromosomal aberration test on mammalian cells. No direct cytogenetic effect was found in the chromosomal aberration test with RF-EMF alone. The comet assay showed nearly negative results for RF-EMF alone, with a small increase in tail moment. RF-EMF showed a potentiation effect in the comet assay when combined with model clastogens.
Koh EK, Ryu BK, Jeong DY, Bang IS, Nam MH, Chae KS · 2008
Researchers examined the effects of power frequency magnetic fields on cell growth in DU145, PC3, and LNCaP prostate cancer cells in vitro. The cells were exposed to various intensities and durations of 60-Hz sinusoidal magnetic fields with various serum concentrations. MF exposure induced significant cell growth inhibition and apoptosis in an intensity- and time-dependent manner, with increased cell cycle arrest, cleaved Caspase-3, and reactive oxygen species. Pretreatment with a Caspase-3 inhibitor or the antioxidant N-acetyl-L-cysteine significantly attenuated the magnetic field-induced growth inhibition and cell death. Media replacement experiments did not alter the magnetic field effects.
Rao VS et al. · 2008
The study used neuronal cells differentiated from a mouse embryonic stem cell line and a frequency-tunable applicator to examine calcium dynamics in real time. Control cells showed about five spontaneous calcium spikes per cell in 60 minutes, while exposure to 800 MHz RF radiation at 0.5 W/kg increased spikes to 15.7 per cell. The increase depended on frequency but not on SAR between 0.5 and 5 W/kg, and involved N-type calcium channels and phospholipase C enzymes. Microfilament disruption prevented the calcium spikes.
Pavicic I, Trosic I · 2008
Researchers exposed V79 cells to continuous wave frequencies of 864 MHz and 935 MHz for 1, 2, or 3 hours. Growth was significantly increased after two- and three-hour exposures to 864 MHz and after three-hour exposure to 935 MHz, measured 72 hours after irradiation. Colony-forming ability and cell viability did not significantly differ from control cells. The two fields showed similar effects on growth, colony-forming ability, and viability, with impact being time-dependent.
Guler G, Turkozer Z, Tomruk A, Seyhan N · 2008
Partsvania B, Sulaberidze T, Modebadze Z, Shoshiashvili L. · 2008
Researchers studied how extremely low-frequency magnetic fields at 8.34 and 217 Hz affected the ability of single neurons in the mollusk Helix Pomatia to habituate to repeated stimuli. Brain ganglia were exposed to magnetic fields with peak values between 1 and 6 mT using Helmholtz coils, and neuron activity was recorded with a standard microelectrode technique. Exposure caused dehabituation, which the researchers described as occurring through degradation of the signal to noise ratio and alteration of the neuron's normal function.
Ahmed Z, Wieraszko A. · 2008
Researchers investigated the influence of a pulsed magnetic field on hippocampal evoked potentials in vitro. Exposure to a pulsed magnetic field at 0.16 Hz and 15 mT, applied for 30 minutes, amplified the population spike and the slope of EPSP recorded from hippocampal tissue. The amplification was additive to previously induced long-term potentiation and occurred in an NMDA-independent way. The pulsed magnetic field also modified paired-pulse facilitation and paired-pulse inhibition, suggesting it affects both excitatory and inhibitory processes in the hippocampus.