Daniells et al. · 1998
Researchers used transgenic Caenorhabditis elegans strain PC72 carrying a heat-shock promoter driving a beta-galactosidase reporter gene. The nematodes were exposed in a transverse electromagnetic cell at 750 MHz and 27 dBm, with the cell held at 25°C in a shielded incubator. Significant stress responses were observed at 2 and 16 hours but not at 4 or 8 hours. Lower power levels of 21 dBm produced greater responses than 27 dBm at both 750 and 300 MHz, a pattern opposite to that expected from simple heating. In a 5 x 5 multiwell plate, wells in rows nearest the exposure showed the strongest response, while the most distant row did not rise above control levels, suggesting a shadow effect.
Chiang H · 1998
The study aimed to investigate microwave and ELF electromagnetic field effects on intercellular communication. The mechanism of gap junctional intercellular communication inhibition by ELF magnetic fields may involve hyperphosphorylation of connexins by protein kinase C, not transcriptional or translational dysregulation.
Novoselova ET, Fesenko EE. · 1998
Researchers studied whether weak electromagnetic waves in the centimeter range could affect tumor necrosis factor production in macrophages from mice. Whole-body microwave irradiation of male NMRI mice, exposure of macrophages in vitro, and irradiation of culture medium with 8.15-18 GHz at a power density of 1 microW/cm2 each caused a significant enhancement of tumor necrosis factor production in peritoneal macrophages.
Grigor'ev IuG, Stepanov VS · 1998
Researchers investigated how prior low-level electromagnetic field exposure affects memory formation (imprinting) in chicks. EMF at power densities from 0.4 to 10 mW/cm2 was found to potentially influence the forming of memory (imprinting). The study showed the possibility of EMF-modulated information being fixed in the embryonic brain during the natal period and conserved after birth.
Behari J, Kunjilwar KK, and Pyne S · 1998
Researchers studied the effect of low-level amplitude-modulated radiofrequency radiation on Na+–K+-ATPase activity in the brains of developing male Wistar rats aged 23 days. Rats were exposed to carrier wave frequencies of 147 MHz and its sub-harmonic frequencies 73.5 and 36.75 MHz, amplitude modulated at 16 and 76 Hz, for 30–35 days at 3 hours per day. Na+–K+-ATPase activity increased by around 19–20% in rats exposed with amplitude modulation at 16 Hz, and by around 15–16% in rats exposed with amplitude modulation at 76 Hz, compared to controls. The researchers concluded that the effect on Na+–K+-ATPase activity was insensitive to the carrier wave frequencies under investigation.
Kavaliers M, Choleris E, Prato FS, Ossenkopp K · 1998
Researchers studied how nitric oxide (NO) and nitric oxide synthase (NOS) influence opioid-induced antinociception in the land snail Cepaea nemoralis, and whether these chemicals play a role in the effects of extremely low frequency (ELF) magnetic field exposure. Pain relief was measured by how long snails took to withdraw their foot from a thermal stimulus of 40°C. Exposure to a 60-Hz magnetic field at 141 μT peak for 15 minutes reduced the enkephalinase-induced antinociception in the snails. The inhibitory effects of the magnetic field were significantly reduced by a nitric oxide synthase inhibitor and significantly enhanced by a nitric oxide releasing agent.
Phillips et al. · 1998
Researchers exposed Molt-4 T-lymphoblastoid cells in vitro to pulsed radiofrequency signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal) to detect DNA damage. The alkaline comet assay was used to measure DNA single-strand breaks in exposed cell cultures compared to sham-exposed cultures. At an SAR of 24 μW g−1, exposure to the iDEN® signal for 2 h and 21 h significantly increased DNA damage, while at 2.4 μW g−1 the same signal significantly decreased DNA damage. The researchers concluded that the data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.
Vijayalaxmi, Mohan, N, Meltz, ML, Wittler, MA, · 1997
Stagg RB, Thomas WJ, Jones RA, Adey WR · 1997
Researchers exposed transformed and normal rat glial cells to an 836.55 MHz packet-modulated RF field at power densities of 0.09, 0.9, and 9 mW/cm2, with SARs from 0.15 to 59 muW/g. Primary rat glial cells showed no significant differences in DNA synthesis between sham and RF-exposed conditions for either log-phase or serum-starved cultures. C6 glioma cells exposed at 5.9 muW/g SAR showed small but significant increases in thymidine incorporation in 38% of experiments. Growth curves showed no differences between sham and RF-exposed cultures for either cell type, and doubling times of C6 glioma cells did not differ significantly.
Safronova VG et al. · 1997
Klug S, Hetscher M, Giles S, Kohlsmann S, Kramer K, · 1997
Researchers exposed 9.5-day-old rat embryos for up to 36 hours to radiofrequency electric and magnetic fields with modulation frequencies of 16, 60, and 120 Hz. The exposure included electric field strengths of 60 and 600 V/m, magnetic inductions of 0.2 and 2.0 microtesla, and specific absorption rates of 0.2, 1.0, and 5.0 W/kg. Neither the electric nor the magnetic fields interfered significantly with normal embryo growth and differentiation when assessed on day 11.5 using a scoring system, photographs, histology, and protein content.
Ivaschuk OI et al. · 1997
Researchers exposed nerve growth factor-treated PC12 rat pheochromocytoma cells to a packet-modulated 836.55 MHz radiofrequency field at power densities of 0.09, 0.9, and 9 mW/cm2 for 20, 40, or 60 minutes, with an intermittent 20-minute on/off regimen. Sham-exposed cells served as controls, and c-fos and c-jun expression was measured by Northern blot analysis of total RNA. C-fos transcript levels did not change after 20 minutes at any intensity, while c-jun transcripts decreased by 38% only after 20 minutes at 9 mW/cm2.
Gos, P, Eicher, B, Kohli, J, Heyer, WD · 1997
Researchers exposed exponentially growing Saccharomyces cerevisiae cells to electromagnetic fields from 41.682 GHz to 41.710 GHz in 2 MHz increments at power densities of 0.5 and 50 microW/cm2. Cell division was assessed by time-lapse photography using two identical chambers that allowed concurrent control and exposure experiments. Control experiments showed the cells were dividing at submaximal rates, ensuring that any increase or decrease in division rate could be observed. No consistently significant differences were found between exposed and unexposed cells across multiple independent experiment series.
Cain CD, Thomas DL, Adey WR · 1997
The study tested whether a TDMA-modulated RF field and the tumor promoter TPA together increase focus formation of transformed cells cocultured with parental C3H/10T1/2 murine fibroblasts. Cell cultures were exposed to an 836.55 MHz TDMA-modulated field at specific absorption rates of 0.15, 1.5, and 15 μW/g in a repeating cycle of 20 minutes on and 20 minutes off continuously for 28 days. RF exposure did not significantly alter TPA-induced focus formation at any of the tested exposure levels across multiple independent experiments.
Antonopoulos A, Eisenbrandt H, Obe G, · 1997
Human peripheral lymphocytes were incubated in the presence of high-frequency electromagnetic fields of 380, 900 and 1800 MHz. The measured endpoints were cell cycle progression and the frequencies of sister-chromatid exchanges. No differences between treated and control cultures could be found.
Malyapa RS et al. · 1997
Researchers exposed mouse C3H 10T1/2 fibroblasts and human glioblastoma U87MG cells to FMCW (835.62 MHz) and CDMA (847.74 MHz) radiation at 0.6 W/kg SAR for up to 24 hours. They used the alkaline comet assay to measure DNA damage. No significant differences were found between exposed cells and sham controls.
Malyapa RS et al. · 1997
Researchers used the alkaline comet assay to test whether 2450 MHz radiation causes DNA damage in cultured mammalian cells. Exponentially growing U87MG and C3H 10T1/2 cells were exposed to 2450 MHz CW radiation at SARs of 0.7 and 1.9 W/kg for durations of 2 h, 2 h followed by 4-h incubation, 4 h, and 24 h. No significant differences were observed between the test group and the controls after exposure.
Persson BRR, Salford LG, Brun A · 1997
Researchers studied blood-brain barrier permeability in Fischer 344 rats of both sexes exposed to radio frequency electromagnetic fields. The exposure used 915 MHz microwaves delivered as either pulse-modulated or continuous wave signals. The rate of pathological leakage rose from 0.17 in controls to 0.39 across all exposed rats, a highly significant difference. Continuous wave exposure produced a higher rate of pathological rats (0.50 ± 0.07) than pulse-modulated exposure (0.35 ± 0.03), and that difference was also statistically significant.
Olchowik G · 1997
Researchers investigated the influence of hydrocortisone and microwave radiation on bone in rats. Hydrocortisone hemisuccinate was administered intraperitoneally for 12 weeks with concomitant microwave irradiation at two power densities. The results indicated a protective effect of electromagnetic microwave radiation on bone tissue exposed to corticotherapy.
Maes A, Collier M, Van Gorp U, Vandoninck S, Verschaeve L · 1997
Researchers exposed cells to 935.2 MHz microwaves alone and in combination with mitomycin C and found no direct cytogenetic effect. Combined exposure to microwaves followed by mitomycin C produced a very weak effect compared to mitomycin C alone.
Koldayev VM, Shchepin YV, · 1997
The aim of the study was to investigate effects of electromagnetic radiation on sea-urchin embryos. Electromagnetic radiation caused a decrease in the number of fertilized eggs and an increase in the number of zygotes with abnormal fertilization envelopes in sea-urchins.
Chattopadhyay SK, Toews KA, Butt S, Barlett R, Brown HD · 1997
Acetylcholinesterase and NADPH cytochrome-P450 reductase show the same temperature versus activity profile in AOT reverse micelles as in buffered dilute solution. In reverse micelles, inhibitors such as propidium and d-tubocurarine have much less effect on indophenol-acetate hydrolysis than in dilute solution, while other inhibitors act the same. The internal pH of reverse micelles depends on available hydrogen ions, low-molarity buffers often cannot keep pH constant, and proton-yielding reactions proceed dramatically faster than in dilute solution at the same acidic pH.
Rojavin MA, Ziskin MC · 1997
Researchers injected BALB/c mice with ketamine 80 mg/kg or chloral hydrate 450 mg/kg and exposed them to 61.22 GHz millimeter waves at 420 W/kg peak specific absorption rate for 15 minutes. Millimeter wave exposure increased anesthesia duration by about 50% compared to sham exposure, which had no effect.
Pu, JS, Chen, J, Yang, YH, Bai, YQ · 1997
Penafiel LM, Litovitz T, Krause D, Desta A, Mullins JM · 1997
