Unknown authors · 2002
Researchers exposed differentiating IMR-32 neuroblastoma cells to 60 Hz magnetic fields at 50, 100, and 200 microT for 4 hours. They measured APP695 mRNA levels using northern hybridization with Digoxygenin-labeled probes. The results provided no support for any relationship between APP695 gene transcription and either differentiation age or magnetic field exposure.
Pologea-Moraru R, Kovacs E, Iliescu KR, Calota V, Sajin G · 2002
Researchers studied the effects of low-power microwaves at 2.45 GHz on the membrane fluidity of rod photoreceptor cells. The researchers expected the retina to be very sensitive to microwave irradiation due to the polar character of photoreceptor cells and high water content.
Miyakoshi, J., Yoshida, M., Tarusawa, Y., et al. · 2002
Unknown authors · 2002
Researchers analyzed expression of immediate early response genes c-fos, c-jun, and c-myc in human glioblastoma T98G cells exposed to 1-500 μT 60 Hz elliptically polarized magnetic fields for up to 3 h. No statistically significant differences were found in gene expression ratios at both transcriptional and translational levels for c-fos and c-jun at 30 min and for c-myc at 180 min after serum stimulation. Similarly, exposure to linearly or circularly polarized 500 μTr fields produced no significant change in expression ratios at both transcriptional and post-transcriptional levels.
Unknown authors · 2002
However, research reports indicate that living cells may respond to power-frequency fields well below the thermal noise limits. The study proposes that published thermal arguments may not fully account for all membrane force fields of thermal origin, and that a full accounting could show smaller net thermal noise fields in the power-frequency range.
Unknown authors · 2002
This 2002 theoretical study challenged the widely accepted belief that thermal noise in cell membranes would prevent power frequency electric and magnetic fields from affecting human cells. The researchers argued that previous thermal noise calculations were incomplete and that when all thermal forces are properly accounted for, the actual noise may be lower than thought, potentially allowing environmental EMF to influence cellular membranes.
Liu Y, Weng E, Zhang Y, Hong R. · 2002
Researchers exposed mice to a 50 Hz sinusoidal electromagnetic field at 0.2 mT or 6.0 mT for 2 weeks, and measured markers of the antioxidant system and cell membrane fluidity in brain and liver tissue. Malondialdehyde content in brain and liver increased with exposure, while total antioxidant capability decreased at both field strengths. When electromagnetic field exposure was combined with lead, the researchers observed synergic effects on lipid peroxidation.
Liu X, Shen H, Shi Y, Chen J, Chen Y, Ji A. · 2002
Trosic I, Busljeta I, Kasuba V, Rozgaj R. · 2002
Researchers exposed adult male Wistar rats to continuous 2450 MHz radiofrequency microwave radiation for 2 hours a day, 7 days a week, for up to 30 days, at a power density of 5–10 mW/cm2. Peripheral blood smears were examined for micronuclei in polychromatic erythrocytes as an indicator of genotoxicity. Micronuclei per 1000 PCEs were significantly increased after eight irradiation treatments compared with sham-exposed controls. The researchers noted that an adaptive mechanism in both erythrocytopoiesis and genotoxicity likely appeared during the subchronic irradiation treatment.
Unknown authors · 2002
Female Sprague Dawley rats were MF or sham exposed for 2 weeks at a flux density of 100 microTesla. Proliferation of epithelial cells in the mammary tissue and adjacent skin was examined by in vivo labeling with bromodeoxyuridine (BrdUrd) and in situ labeling of Ki-67 protein by the antibody MIB-5. MF exposure significantly enhanced BrdUrd and Ki-67 labeling in the mammary epithelium, indicating a marked increase in cell proliferation. Melatonin levels in pineal or mammary glands were not affected by MF exposure. Topical application of 12-O-tetradecanoylphorbol-13-acetate increased BrdUrd and Ki-67 labeling in skin epithelial cells, particularly hair follicles, but not in mammary tissue.
Unknown authors · 2002
German researchers exposed female rats to 50 Hz magnetic fields at 100 microTesla (similar to power lines) for two weeks and found significantly increased cell division in mammary gland tissue. The study challenges the popular "melatonin hypothesis" by showing breast tissue effects occurred without changes in melatonin levels. This provides direct evidence that magnetic field exposure can stimulate breast cell proliferation, potentially explaining increased cancer risk.
Peyman A, Rezazadeh AA, Gabriel C · 2001
Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.
Unknown authors · 2001
Researchers conducted a population-based case-control study across former West Germany. They measured 24-hour residential magnetic fields for 514 children with acute leukemia and 1,301 control children. Childhood leukemia and 24-hour median magnetic fields showed only a weak relationship. However, a significant association emerged for magnetic field exposure during the night.
Unknown authors · 2001
Each woman provided data over a 72-hour period in two different seasons, including bedroom magnetic field and ambient light measured every 30 seconds, personal magnetic field measured at 30-second intervals, and complete nighttime urine samples on three consecutive nights. Lower nocturnal urinary 6-sulfatoxymelatonin levels were associated with more hours of daylight, older age, higher body mass index, current alcohol consumption, and current use of beta blockers, calcium channel blockers, or psychotropics. After adjusting for these factors, higher bedroom magnetic field levels were associated with significantly lower urinary 6-sulfatoxymelatonin concentration during the same night, primarily in women using those medications and during times of year with the fewest hours of darkness.
Unknown authors · 2001
Researchers measured magnetic fields and melatonin levels in 203 women's bedrooms over 72-hour periods across different seasons. They found that higher bedroom magnetic field levels were associated with significantly lower nighttime melatonin production, particularly in women taking certain medications. This suggests that common household magnetic fields can disrupt the body's natural sleep hormone production.
Unknown authors · 2001
Researchers independently replicated a study testing whether a 1.2 microT, 60 Hz magnetic field alters the effects of melatonin and tamoxifen on MCF-7 human breast cancer cells. In the melatonin experiment, repeated three times, melatonin reduced cell numbers by 16.7% after seven days, but this reduction disappeared when cells were exposed to the magnetic field. In the tamoxifen experiment, repeated nine times, tamoxifen reduced cell growth by 18.6% and 25% on days six and seven without the field, but only by 8.7% and 13.1% with the field. The results were consistent with the original findings of Harland and Liburdy.
Unknown authors · 2001
EPA researchers tested whether 60 Hz magnetic fields at 1.2 microT could interfere with melatonin and tamoxifen's ability to inhibit breast cancer cell growth. They found that magnetic field exposure completely blocked melatonin's cancer-fighting effects and significantly reduced tamoxifen's effectiveness. This suggests power line frequency EMF may interfere with the body's natural cancer protection mechanisms.
Lyskov E, Sandström M, Mild KH · 2001
Researchers investigated possible neurophysiological effects of an intermittent 15 sec on/off cycle, 60 Hz, 10 μT magnetic field on patients with perceived electromagnetic hypersensitivity (EHS) and control subjects during rest and a mental arithmetic task. Magnetic field exposure did not affect autonomic system or electroencephalographic variables in either group. EHS patients and controls showed significant differences in heart rate, heart rate spectrum ratio, and electrodermal activity, while EEG characteristics did not differ between groups.
Unknown authors · 2001
Unknown authors · 2001
Japanese researchers exposed breast cancer cells to 50 Hz magnetic fields at extremely low levels (1.2 microT and 100 microT) and found these fields disrupted melatonin's cancer-fighting signals. The magnetic fields prevented melatonin from properly inhibiting cellular pathways that normally help control cancer cell growth.
Boscol P et al. · 2001
The study investigated the immune systems of 19 women with a mean age of 35 years who had been exposed to electromagnetic fields from radiotelevision broadcasting stations in their residential area for at least 2 years, with a mean exposure duration of 13 years. The exposed group had mean field levels of 4.3 plus or minus 1.4 V/m in the range 500 KHz to 3 GHz, while the control group had nearby residential exposure of less than 1.8 V/m. The exposed women showed statistically significant reductions in several immune cell types and lower in vitro production of IL-2 and interferon-gamma by peripheral blood mononuclear cells. The researchers concluded that high frequency electromagnetic fields reduce cytotoxic activity in the peripheral blood of women without a dose-response effect.
Unknown authors · 2001
Researchers demonstrated that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms. The field antagonizes the shift in cell membrane surface charges during early differentiation and modulates hyperpolarizing K channels by increasing intracellular calcium. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. The authors propose that cells are normally protected against electromagnetic insult.
Sebastian JL, Munoz S, Sancho M, Miranda JM · 2001
Researchers calculated electric field intensity using the finite element method in single- and multilayer spherical, cylindrical, and ellipsoidal mammalian cell models exposed to 900 and 2450 MHz plane waves. They analyzed how cell geometry and orientation relative to the external field influence the electric field induced in the membrane and cytoplasm. The study found that cytoplasmic and extracellular bound water layers play a significant role in determining electric field intensity for cylindrical and ellipsoidal models.
Vijayalaxmi et al. · 2001
Eight adult male Sprague-Dawley rats were exposed to 2450 MHz RFR in circularly polarized waveguides, and eight sham-exposed rats were kept in similar waveguides without RFR transmission. Four rats treated with mitomycin-C served as positive controls, and all rats were necropsied 24h after exposure to examine peripheral blood and bone marrow smears for micronuclei in polychromatic erythrocytes. The incidence of micronuclei per 2000 polychromatic erythrocytes was not significantly different between RFR-exposed and sham-exposed rats.
Unknown authors · 2001
Researchers induced dopamine neuron damage in newborn rats by infusing 6-OHDA into the brain ventricles on postnatal day 3. At two months of age, the rats were exposed to a 10 Hz, 1.8–3.8 mT magnetic field for one hour daily over 14 days, while a sham-exposed group had the solenoid turned off. After exposure, magnetic-field-exposed rats with dopamine damage showed reduced irritability and oral activity when given a D1 receptor agonist and increased catalepsy when given a D1 receptor antagonist. The authors concluded that extremely low frequency magnetic fields reduce the reactivity of central dopamine D1 receptors.
