Lai H, Carino MA, Horita A, Guy AW, · 1994
Researchers exposed rats to pulsed 2450-MHz microwaves for 45 minutes at a power density of 1 mW/cm2 with a whole body specific absorption rate of 0.6 W/kg. This exposure decreased cholinergic activity in the hippocampus as measured by sodium-dependent high-affinity choline uptake. Microinjection of beta-funaltrexamine (1 microgram) into the septum before exposure blocked the microwave-induced decrease.
Singh N, Rudra N, Bansal P, Mathur R, Behari J, Nayar U · 1994
Researchers exposed Twenty-three days old rats to 2.45 GHz microwaves at 1.0 mW/cm2 for sixty days and measured poly ADPR polymerase activity in various organs. The enzyme activity increased by 20% in liver and 35% in testis, while it decreased by 53% in brain diencephalon and 20% in cortex. No change was observed in spleen and kidney, and the changes were accompanied by alterations in NAD+ levels.
Unknown authors · 1994
Researchers exposed SV40-transformed human fibroblasts to a 60 Hz continuous-wave sinusoidal electromagnetic field. Exposure resulted in increased levels of virally derived mRNA and protein of large T-antigen. The findings provide evidence that foreign DNA integrated into cells can be affected by EM fields under conditions known to cause increased transcripts from endogenous cellular genes.
Bergqvist B et al. · 1994
Researchers studied the effect of 2.45 GHz microwave radiation on the permeability of unilamellar phosphatidylcholine liposomes. Leakage of 5(6)-carboxyfluorescein was measured using spectrofluorimetry after exposure to microwaves or thermal heating for 5-20 min intervals. The microwave exposure did not result in any non-thermal increase in permeability above that produced by thermal heating. The study refutes earlier results that reported increased liposome permeability due to microwave exposure.
Yee KC, Chou CK, Guy AW · 1994
Researchers investigated the effect of microwave exposure on conduction velocity of frog ventricular muscle. Thirty-two frog hearts were divided into four groups and placed in temperature-controlled waveguides with Ringer's solution. One group served as control while three groups were exposed for 2 hours to pulsed 2,450 MHz microwave fields at SARs of 0.003, 2, and 6 W/kg. No significant difference in conduction velocity was found between control and exposed groups.
Akoev IG, Mel'nikov VM, Usachev AV, Kozhokaru AF, · 1994
Researchers studied whether exposure to low-intensity radiofrequency radiation after a lethal dose of gamma-radiation could modify the resulting injury in mice. The radiofrequency exposure lasted up to 23 hours at an intensity of 5 plus or minus 1.5 microwatts per square centimeter, covering frequency ranges of 2-8, 8-18, and 19-27 GHz with a swing frequency of 12-14 Hz. A clearly pronounced modification of acute radiation injury was obtained when the radiofrequency exposure was applied immediately after the gamma-radiation.
Somosy Z, Thuroczy G, Koteles GJ, Kovacs J · 1994
Researchers investigated the distribution and activity of Ca(2+)-ATPase in small intestine epithelial cells of mice after total body exposure to 2450 MHz microwave irradiation modulated at 16 Hz and X-ray irradiation. In control animals, enzyme activity was present in the brush border and lateral membranes, and lateral membrane activity was inhibited by quercetin. Microwave irradiation immediately decreased Ca(2+)-ATPase activity on lateral membranes, 1 Gy X-ray caused a similar reversible decrease within 24 hours, and 5 Gy X-ray reduced activity on both apical and lateral membranes persisting up to 24 hours.
Unknown authors · 1993
Unknown authors · 1993
Maes A, Verschaeve L, Arroyo A, De Wagter C, Vercruyssen L · 1993
Researchers exposed human peripheral blood lymphocytes to 2450 MHz microwaves for 30 and 120 minutes at constant body temperature. Exposure caused a marked increase in chromosome aberrations, including dicentric chromosomes and acentric fragments, and micronuclei. Microwave exposure did not influence cell kinetics or sister chromatid exchange frequency.
Unknown authors · 1993
DMBA was given orally at 5 mg/kg on the first day and weekly thereafter up to a total dose of 20 mg per rat. Eight weeks after DMBA application, the magnetic-field-exposed rats exhibited significantly more tumors than sham-exposed animals. At the end of the three-month exposure, tumor incidence in the exposed group was 50% higher than in the sham group, a statistically significant difference. Tumor size as estimated by palpation was also significantly larger in the magnetic-field-exposed rats compared with sham-exposed rats.
Unknown authors · 1993
Researchers conducted a telephone interview survey in November 1987 to assess depressive symptoms and headaches in relation to proximity to an alternating-current transmission line. Proximity was defined as residing on a property abutting the right-of-way or being able to see the towers from one's house or yard. Proximity was positively associated with depressive symptoms with an odds ratio of 2.8 (95% CI 1.6-5.1). The association was not explained by demographic variables associated with depression or by attitudes about power lines or other environmental issues. Nonmigraine headaches had a weaker association with proximity (odds ratio = 1.5, 95% CI 0.76-2.8) and self-reported migraine headaches exhibited no association (odds ratio = 0.99, 95% CI 0.29-3.4).
Field AS, Ginsburg K, Lin JC · 1993
Researchers studied the effects of pulsed microwaves on membrane input resistance and action potential interval statistics in spontaneously active ganglion neurons of land snails (Helix aspersa). Experiments were conducted at strictly constant temperature, so macroscopic heating was not responsible for any observed effects. Exposure significantly increased mean input resistance, while mean firing rate and mean input current were not affected. The net input current was found to be more variable in exposed neurons, though changes in interspike interval standard deviation and input current autocorrelation were not consistent across neurons.
Seaman RL, DeHaan RL · 1993
Researchers studied inter-beat intervals of aggregated cardiac cells from chicken embryos during 190-second exposures to 2.45 GHz microwaves. The inter-beat interval decreased during exposures at 42.0 W/kg and higher with continuous-wave or square-wave modulation, consistent with thermal effects. Increases occurred during continuous-wave exposures at 1.2-12.2 W/kg and decreases after pulse-modulated exposures at 8.4-12.2 W/kg, which were not consistent with simple thermal effects.
Unknown authors · 1993
Researchers exposed growing Escherichia coli strain AB1157 to a 1 Hz field at 1 or 3 kV/m and found no effect on spontaneous or UV-induced mutation frequencies to rifampicin resistance. Growth in the presence of charge did not alter the UV sensitivity of strains AB1157, TK702 umuC, or TK501 umuC uvrB. Although plasmid pKM101 increased UV resistance in repair-deficient strains, pre-growth in electric fields did not further increase UV resistance, and low frequency fields did not affect mitomycin C-induced mutation frequencies.
Somosy Z, Thuroczy G, Kovacs J · 1993
Researchers investigated pyroantimonate-precipitable calcium in mouse intestinal epithelial cells after whole-body exposure to 2450 MHz continuous and 16 Hz square-modulated microwaves. Immediately after modulated irradiation at 0.5 and 1 mW/cm², calcium deposits rapidly appeared on the cytoplasmic side of lateral membranes and in the junctional complex including tight junctions. These changes were reversible, with calcium distribution returning to control-like patterns after 24 hours. Continuous-wave exposure at the same energy did not alter calcium distribution.
Rotkovska D, Bartonickova A, Kautska J · 1993
Lange DG, D'Antuono ME, Timm RR, Ishii TK, Fujimoto JM. · 1993
Unknown authors · 1993
Researchers measured intracellular calcium concentration in mouse lymphocytes using a fluorescent probe during a 60-minute exposure to cyclotron resonance conditions for calcium ions. They tested resonance conditions at 16 Hz and 50 Hz with DC field amplitudes shifting the frequency up to 25 percent either side of the calculated optimum. Concanavalin A treatment increased intracellular calcium significantly, but no change was detected under any magnetic field combination tested.
Unknown authors · 1993
The review discusses evidence of direct and indirect genetic toxicity effects for electric and magnetic fields at 50- and 60-Hz and miscellaneous pulsed exposures. Epidemiologic studies have reported a modestly increased risk of childhood leukemia associated with certain electric power wire configurations. Exposure conditions vary greatly among different end points measured, making comparisons and conclusions among experiments difficult. Most available evidence does not suggest that electric and/or magnetic fields cause DNA damage. Some positive findings and limitations in the studies suggest a need for additional work.
Unknown authors · 1992
Researchers used a nuclear run-off assay to measure specific gene transcription in CEM-CM3 T-lymphoblastoid cells exposed to a 1 gauss, 60 Hz sinusoidal magnetic field for 15 to 120 minutes. They observed time-dependent and cell density-dependent changes in the transcription of c-fos, c-jun, c-myc, and protein kinase C beta-form. Slot-blot analysis showed that changes in transcript levels paralleled the changes in gene transcription.
Unknown authors · 1992
Researchers exposed human immune cells to 60 Hz magnetic fields at 1 gauss (similar to power line levels) for 15-120 minutes and found significant changes in gene activity. Four important genes involved in cell growth and signaling showed altered transcription patterns that varied with exposure time and cell density. This demonstrates that even brief exposure to common power line frequencies can directly affect how genes function in human cells.
Chou CK, Guy AW, Kunz LL, Johnson RB, Crowley JJ, Krupp JH · 1992
Two hundred male Sprague-Dawley rats were assigned in equal numbers to radiation-exposure and sham-exposure conditions, with exposure beginning at 8 weeks of age and continuing daily for 25 months. The experimental rats were exposed to 2,450-MHz pulsed microwaves at 800 pps with a 10-microseconds pulse width, square-wave modulated at 8-Hz. Blood samples were analyzed at regular intervals for serum chemistries, hematological values, protein electrophoretic patterns, thyroxine, and plasma corticosterone levels.
Lai H, Carino MA, Horita A, Guy AW, · 1992
Researchers investigated which opioid receptor subtypes mediate a microwave-induced decrease in central cholinergic activity in rats. Rats were pretreated with specific antagonists of mu, delta, and kappa opioid receptors before exposure to microwaves. All three receptor subtypes were involved in the decrease in cholinergic activity in the hippocampus.
Lai H, Carino MA, Horita A, Guy AW · 1992
Researchers exposed rats to single 45-minute and repeated daily 45-minute microwave sessions at 2450 MHz, 1 mW/cm², with a whole-body SAR of 0.6 W/kg. After a single exposure, receptor concentration increased in the cerebral cortex but not in the hippocampus or cerebellum. No significant change in binding affinity of the receptors was observed in any of the brain regions studied. After repeated exposures, no significant change in receptor concentration was found in the cerebral cortex. Handling and exposure procedures did not significantly affect benzodiazepine receptors.
