Sukhotina I, Streckert JR, Bitz AK, Hansen VW, Lerchl A · 2006
Researchers exposed isolated pineal glands from Djungarian hamsters to 1800 MHz continuous wave or GSM-modulated signals at SAR levels of 8, 80, 800, and 2700 mW/kg for 7 hours. At 800 mW/kg SAR both signal types significantly enhanced melatonin release, but at 2700 mW/kg SAR continuous wave elevated melatonin while GSM-modulated exposure suppressed it. The authors concluded that the data do not support the melatonin hypothesis that nonthermal radiofrequency exposure suppresses melatonin synthesis.
Scarfi MR et al. · 2006
Researchers exposed human peripheral blood lymphocytes from 10 healthy donors to 900 MHz GSM signals at SARs of 0, 1, 5, and 10 W/kg for 24 hours. The cytokinesis-block micronucleus assay showed no genotoxic or cytotoxic effects across the range of SARs investigated. Two independent laboratories (ENEA Rome and CNR-IREA Naples) each tested five donors and cross-scored slides, confirming the findings.
Sanchez S et al. · 2006
Researchers exposed five-week-old female hairless rats to GSM-900 or -1800 signals for 2 hours per day, 5 days a week, for 12 weeks. Skin thickness showed no significant difference between exposed and sham-exposed groups. Cellular proliferation measured by Ki-67 remained within normal range in exposed epidermis. Levels of filaggrin, collagen, and elastin did not differ significantly among groups.
Sanchez S et al. · 2006
Apoptosis was not induced in isolated cells and reconstructed epidermis thickness and proliferation were unchanged. No change in heat shock protein expression was observed in isolated keratinocytes. A slight but significant increase in Hsp70 expression was observed in reconstructed epidermis after 3 and 5 weeks of culture. Fibroblasts showed a significant decrease in Hsc70 depending on culture conditions.
Remondini D et al. · 2006
Researchers exposed six human cell types to 900 and 1800 MHz microwaves and analyzed gene expression using whole-genome cDNA arrays. NB69 neuroblastoma cells, T lymphocytes, and CHME5 microglial cells did not show significant changes in gene expression. EA.hy926 endothelial cells, U937 lymphoblastoma cells, and HL-60 leukemia cells showed between 12 and 34 up- or down-regulated genes. The affected gene families did not indicate a stress response.
Natarajan M et al. · 2006
Human Mono Mac 6 cells were exposed intermittently to pulsed EMF for 90 minutes with a pulse width of 0.79 ns and a repetition rate of 250 pps at 1 kV/cm. Cells exposed to the EMF showed a 3.5-fold increase in NFKB DNA-binding activity at 24 hours postexposure. No difference was found in NFKB-dependent gene expression profiles at 8 or 24 hours postexposure. Pulsed EMF exposure did not induce NFKB-driven luciferase activity, indicating the activation was functionally inactive.
Merola P et al. · 2006
The study examined whether a modulated 900 MHz radiofrequency field at a specific absorption rate higher than the ICNIRP occupational reference level could alter cell proliferation, differentiation, and apoptosis in a neuroblastoma cell line. Cells were exposed for 24, 48, and 72 hours and tested using WST-I assay, molecular markers, caspase activation, and PARP cleavage detection. Combined exposures with retinoic acid and camptothecin were also tested to check for interference between the field and chemical agents. Overall, the data suggest that 900 MHz radiofrequency exposure up to 72 hours does not induce significant alterations in the three principal cell activities.
Masuda H et al. · 2006
Researchers exposed hairless female rats to GSM-900 or -1800 signals for 2 hours using a loop antenna on the back. The local specific absorption rate at skin level was about 5 W/kg. Skin thickness and cell toxicity did not differ between exposed and sham-exposed rats. Cell proliferation in the epidermis remained within normal range and no proliferation was seen in the dermis. Levels of filaggrin, collagen, and elastin were not significantly affected by the exposure.
Lee JS, Huang TQ, Kim TH, Kim JY, Kim HJ, Pack JK, Seo JS. · 2006
Researchers exposed human T-lymphocyte Jurkat cells and rat primary astrocytes to 1763 MHz RF radiation at SARs of 2 or 20 W/kg for 30 minutes or 1 hour while temperature was completely controlled at 37 +/- 0.2 degrees C. No detectable difference was observed in the expression levels of HSP90, HSP70, and HSP27, and the phosphorylation status of MAPKs did not change significantly. When TPA alone was applied, MAPKs were phosphorylated in a dose-dependent manner, but RF radiation did not enhance TPA-induced MAPK phosphorylation, and neither TPA nor RF radiation affected HSP induction.
Lantow M, Viergutz T, Weiss DG, Simko M. · 2006
Researchers used human Mono Mac 6 cells and exposed them to a 1,800 MHz GSM-DTX signal at 2 W/kg SAR for 12 hours. They measured cell cycle kinetics, BrdU uptake, apoptosis, and necrosis using flow cytometry. No statistically significant differences were found in apoptosis, necrosis, cell cycle kinetics, or BrdU uptake between RF EMF-exposed cells and sham or incubator controls. Positive controls treated with gliotoxin and PMA showed significant increases in apoptosis and necrosis, and PMA caused a significant accumulation of cells in G0/G1 phase with a reduction in S-phase cells.
Joubert V et al. · 2006
Researchers exposed human neuroblastoma SH-SY5Y cells to GSM-900 at 0.25 W/kg average SAR or continuous-wave 900 MHz at 2 W/kg SAR for 24 hours. No statistically significant difference in apoptosis rate was found between sham-exposed and microwave-exposed cells at either 0 or 24 hours post-exposure. Apoptosis rates were also comparable between sham, continuous-wave, 37°C, and 39°C exposed cells. Three assessment methods including DAPI staining, TUNEL/PI flow cytometry, and caspase-3 fluorimetry gave concordant results.
Hirose H et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations induce apoptosis or stress responses activating p53. Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 mW/kg and CW radiation at 80 mW/kg for 24 or 48 hours, while human IMR-90 fibroblasts were exposed to both modulations at 80 mW/kg for 28 hours. No significant differences in apoptosis, phosphorylated p53 at serine 15, total p53, or downstream gene expression were found between exposed and sham-exposed cells.
Chauhan V et al. · 2006
Researchers exposed HL-60 and MM6 cells to intermittent 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg for 6 hours. No significant changes in gene expression were found between sham-exposed and RF-exposed groups in either cell line. Positive heat-shock controls showed significant increases in HSP27, HSP70, c-fos, and c-jun at both time points.
Chauhan V et al. · 2006
Researchers exposed human lymphoblastoma TK6 cells to 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg. They assessed expression of proto-oncogenes FOS, JUN, and MYC using real-time RT-PCR. They also monitored transcript levels of the heat-shock proteins HSP27 and inducible HSP70. Transcript levels in RF-exposed cells showed no significant difference compared to sham-exposed cells. Positive heat-shock controls showed significant elevation of HSP27, HSP70, FOS, and JUN, and a decline in MYC mRNA.
Stronati L et al. · 2006
The study used alkaline comet assay, metaphase analysis, micronucleus test, and nuclear division index to assess DNA strand breaks, chromosomal aberrations, sister chromatid exchanges, micronuclei, and cell cycling speed. It comprehensively examined whether 24-hour continuous exposure to a 935 MHz GSM signal at 1 or 2 W/kg is genotoxic per se or can influence x-ray genotoxicity. Within the experimental parameters, no effect from the RFR signal was observed in any instance. The SAR values chosen were near the upper limit of energy absorption in localized tissue during cellular telephone use.
Sakuma N et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations act as a DNA damaging agent. Human glioblastoma A172 cells and normal human IMR-90 fibroblasts were exposed to 2.1425 GHz CW and W-CDMA radiation. A172 cells were exposed to W-CDMA at SARs of 80, 250, and 800 mW/kg and CW at 80 mW/kg for 2 and 24 hours, while IMR-90 cells were exposed to both modulations at 80 mW/kg for the same periods. No significant differences in DNA strand breaks were observed between exposed groups and sham controls using alkaline comet assays. The authors concluded that low-level exposures do not act as a genotoxicant up to a SAR of 800 mW/kg.
Maes A, Van Gorp U, Verschaeve L. · 2006
Researchers investigated cytogenetic effects in peripheral blood lymphocytes from subjects professionally exposed to mobile phone electromagnetic fields. The alkaline comet assay, sister chromatid exchange and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to mitomycin C to investigate possible combined effects of RFR and the chemical mutagen. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test.
Simkó M et al. · 2006
The study investigated Hsp70 expression and free radical release in human Mono Mac 6 cells exposed to ultrafine particles and radiofrequency electromagnetic fields. Ultrafine particle exposure increased free radical release by 40-45% above negative control, an effect stronger than heat treatment. Radiofrequency electromagnetic field exposure alone did not change free radical levels. Combined exposure to RF and ultrafine particles did not enhance the particle effect on free radicals. Heat treatment increased Hsp70 expression in a time-dependent manner, while ultrafine particles, RF fields, or their combination had no effect on Hsp70.
Lantow M, Lupke M, Frahm J, Mattsson MO, Kuster N, Simko M. · 2006
The study investigated whether 1,800 MHz RF-EMF can induce ROS release or Hsp70 expression changes in human blood cells using various exposure conditions. PMA treatment significantly increased ROS production in both monocytes and lymphocytes compared to sham or incubator controls. GSM-DTX exposure at 2 W/kg produced a significant difference in monocyte ROS compared to sham, but this was attributed to lower ROS values in the sham condition, while lymphocytes showed no ROS changes. Hsp70 expression in monocytes did not differ after GSM-DTX exposure at 2 W/kg for 1 hour compared to incubator or sham controls at any post-exposure time point.
Lantow M, Schuderer J, Hartwig C, Simko M. · 2006
Heat and PMA treatment significantly increased superoxide radical anions and ROS production in Mono Mac 6 cells. No significant differences in free radical production were detected after RF EMF exposure compared to controls. The GSM-DTX signal at 2 W/kg showed a significant difference versus sham due to a decreasing sham value, but this difference disappeared when compared to incubator controls. No significant effects on HSP70 expression were detected after RF EMF exposures.
Túnez I et al. · 2006
Researchers investigated the effect of transcranial magnetic field stimulation on free radical production and neuronal cell loss caused by 3-nitropropionic acid in rats. 3-nitropropionic acid induced oxidative and nitrosative stress in the striatum and prompted cell loss. Transcranial magnetic stimulation prevented the harmful effects induced by the acid.
Vian A et al. · 2006
The study aimed to investigate how microwave irradiation affects gene expression in plants. Researchers used a carefully calibrated system that mimics environmental electromagnetic fields to measure changes in mRNA encoding a stress-related bZIP transcription factor. Exposure to low-amplitude, short-duration 900 MHz EMF evoked a rapid 3.5-fold accumulation of this mRNA, peaking 5–15 minutes after stimulation, similar to mechanical stimulation.
Hamann W, Abou-Sherif S, Thompson S, Hall S. · 2006
Researchers applied pulsed radiofrequency (20 ms of 500-kHz RF pulses at 2 Hz, max 42°C) to the sciatic nerve or L4 anterior primary ramus in adult rats. Controls included sham-operated and L4 axotomised rats, and tissues were examined 14 days later. Axotomy upregulated ATF3 in L4 DRG neurons regardless of size. PRF applied near the DRG significantly and selectively increased ATF3 in small and medium neurons, while PRF applied to the sciatic nerve in mid-thigh caused no obvious changes.
Ferreri F et al. · 2006
Fifteen male volunteers participated in two sessions one week apart with real or sham GSM mobile phone exposure for 45 minutes in a cross-over, double-blind design. Motor evoked potentials were recorded using a paired-pulse paradigm before and after exposure to assess intracortical excitability. Real exposure significantly modified the intracortical excitability curve with reduced short intracortical inhibition and enhanced intracortical facilitation in the exposed hemisphere compared to the non-exposed hemisphere or sham exposure. Tympanic temperature showed no significant changes during exposure.
Ferreira AR et al. · 2006
Researchers used the micronucleus assay to assess chromosomal damage in erythrocytes from rat offspring exposed to non-thermal UHF-EMF from a cellular phone during embryogenesis. The irradiated group showed a significant increase in micronuclei occurrence. No significant differences were found in any oxidative parameter of offspring blood and liver. The average number of pups in each litter was not significantly altered.
