Interaction of Microwaves and a Temporally Incoherent Magnetic Field on Single and Double DNA Strand Breaks in Rat Brain Cells

Lai, Henry; Singh, Narendra P.

doi:10.1081/jbc-200055046

Cited by 39 publications

(16 citation statements)

References 17 publications

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“…However, since externally imposed electromagnetic 'noise' is spatially coherent, cells are unable to discriminate against it, so it is capable of confusing the biological EMF detection mechanism and inhibits the biological effects induced by applied coherent EMFs. Since then, the 'temporal and spatial coherence hypothesis' of EMF has been supported by many in vitro and in vivo studies [31][32][33][34][35][36][37]. In the present experiment, we found that exposure to a 50-Hz MF for 72 hrs could inhibit the hormone secretion of trophoblasts, while an incoherent ('noise') MF with the same intensity did not.…”

Section: Discussionsupporting

confidence: 61%

Superimposition of an Incoherent Magnetic Field Eliminated the Inhibition of Hormone Secretion Induced by a 50-Hz Magnetic Field in Human Villous Trophoblasts <i>in vitro</i>

Sun

Tan

Pan³

et al. 2010

Cell Physiol Biochem

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The effects of exposure to a sinusoidal 50-Hz magnetic field (MF) and an incoherent (noise) MF on hormone secretion in human first trimester villous trophoblasts were investigated. Trophoblasts were isolated from more than 30 first trimester human chorionic villi of 8-10 weeks gestation. They were cultured and exposed to MFs for different durations. The concentrations of human chorionic gonadotropin (hCG) and progesterone in culture medium were measured by electrochemiluminescence immunoassay. The results showed that exposure of the villous trophoblasts to a 50-Hz MF at 0.4 mT (milli Tesla) for 72 hrs could significantly inhibit the secretion of hCG and progesterone, whereas exposure to an incoherent MF (frequency range between 30 to 90 Hz) with the same conditions did not significantly affect the secretion. However, when the incoherent MF was superimposed on the 50-Hz MF and the cells were exposed to both fields simultaneously, no significant change in hormone secretion was observed. Based on these results, we concluded that 50-Hz MF exposure for 72 hrs could inhibit the hormone secretion of trophoblasts, and an incoherent MF of equal intensity could completely eliminate the effects induced by the 50-Hz MF.

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Section: Discussionsupporting

confidence: 61%

Superimposition of an Incoherent Magnetic Field Eliminated the Inhibition of Hormone Secretion Induced by a 50-Hz Magnetic Field in Human Villous Trophoblasts <i>in vitro</i>

Sun

Tan

Pan³

et al. 2010

Cell Physiol Biochem

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“…Gaps in the sine wave resulted in a reduced response, and interference with the sine wave in the form of superimposed ELF noise also reduced the response [57]. The interfering effect of noise has been shown in the RF range by Lai and Singh [46], who reported that noise interferes with the ability of an RF signal to cause breaks in DNA strands. The decreased effect when noise is added to a signal is yet another indication that EMF energy is not the critical factor in causing a response.…”

Section: The Stress Response and Safety Standardsmentioning

confidence: 94%

“…• As the energy in an EMF stimulus increases, there is an increase in single strand breaks, followed by double strand breaks, suggesting an interaction with EMF at all energy levels [46].…”

Section: Emf-dna Interaction Mechanisms: Electron Transfermentioning

confidence: 99%

Electromagnetic fields stress living cells

2009

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Electromagnetic fields (EMF), in both ELF (extremely low frequency) and radio frequency (RF) ranges, activate the cellular stress response, a protective mechanism that induces the expression of stress response genes, e.g., HSP70, and increased levels of stress proteins, e.g., hsp70. The 20 different stress protein families are evolutionarily conserved and act as 'chaperones' in the cell when they 'help' repair and refold damaged proteins and transport them across cell membranes. Induction of the stress response involves activation of DNA, and despite the large difference in energy between ELF and RF, the same cellular pathways respond in both frequency ranges. Specific DNA sequences on the promoter of the HSP70 stress gene are responsive to EMF, and studies with model biochemical systems suggest that EMF could interact directly with electrons in DNA. While low energy EMF interacts with DNA to induce the stress response, increasing EMF energy in the RF range can lead to breaks in DNA strands. It is clear that in order to protect living cells, EMF safety limits must be changed from the current thermal standard, based on energy, to one based on biological responses that occur long before the threshold for thermal changes. © 2009 Elsevier Ireland Ltd. All rights reserved.Keywords: DNA; Biosynthesis; Electromagnetic fields; ELF; RF Electromagnetic fields (EMF) alter protein synthesisUntil recently, genetic information stored in DNA was considered essentially invulnerable to change as it was passed on from parent to progeny. Mutations, such as those caused by cosmic radiation at the most energetic end of the EM spectrum, were thought to be relatively infrequent. The model of gene regulation was believed to be that the negatively charged DNA was tightly wrapped up in the nucleus with positively charged histones, and that most genes were 'turned off' most of the time. Of course, different regions of the DNA code are being read more or less all the time to replenish essential Abbreviations: EMF, electromagnetic fields; Hz, hertz; ELF, extremely low frequency; RF, radio frequency; MAPK, mitogen activated protein kinase; ERK1\2, extracellular signal regulated kinase; JNK, c-Jun-terminal kinase p38MAPK; SAPK, stress activated protein kinase; NADH, nicotinamide adenine dinucleotide dehydrogenase; ROS, reactive oxygen species.* Corresponding author at: Department of Physiology, Columbia Univer- proteins that have broken down and those needed during cell division. New insights into the structure and function of DNA have resulted from numerous, well-done laboratory studies. The demonstration that EMF induces gene expression and the synthesis of specific proteins [1,2] generated considerable controversy from power companies, government agencies, physicists, and most recently, cell phone companies. Physicists have insisted that the reported results were not possible because there was not enough energy in the power frequency range (ELF) to activate DNA. They were thinking solely of mechanical interaction with a large molec...

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“…Although there exist controversies, the 'temporal and spatial coherence hypothesis' of EMF has hitherto been supported by many in vitro and in vivo studies [33][34][35][36][37][38][39]. Based on their studies, Litovitz et al [23,24,40] indicated that a reasonable hypotheses for accounting for thermalnoise fields being ignored by cells or cells can distinguish between external EMF and thermal noise, is that they do exhibit a distinct difference in spatial behaviors.…”

Section: Discussionmentioning

confidence: 99%

An Incoherent Magnetic Field Inhibited EGF Receptor Clustering and Phosphorylation Induced by a 50-Hz Magnetic Field in Cultured FL Cells

Sun

Ye²,

Fu³

et al. 2008

Cell Physiol Biochem

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Previously, we found that exposure to a 50-Hz magnetic field (MF) at 0.4 mT could induce epidermal growth factor (EGF) receptor clustering in Chinese hamster lung (CHL) fibroblast cells and superposition of an incoherent MF with the same intensity could inhibit the effect. In the present experiment, we investigated the effects of 50-Hz MF exposure at different intensities on EGF receptor clustering and phosphorylation in human amniotic cells (FL), and explored the interaction effect of an incoherent MF. Clustering and phosphorylation of EGF receptors on cellular membrane surface were analyzed using immunofluorescence assessed by confocal microscopy and western blot technology, respectively. EGF treatment served as a positive control. The results showed that, compared with sham exposure, exposure to a 50-Hz MF at 0.1, 0.2 or 0.4 mT for 15 min could significantly induce EGF receptor clustering and enhance phosphorylation on tyrosine-1173 residue in FL cells, whereas exposure to a 0.05 mT field for 15 min did not caused a significant effect. Exposure to an incoherent MF (frequency range between 30 to 90 Hz) at 0.2 mT for the same time neither induced EGF receptor clustering nor enhanced phosphorylation of EGF receptor in FL cells. When superposed, the incoherent MF at 0.2 mT completely inhibited EGF receptor clustering and phosphorylation induced by a 50-Hz MF at 0.1 and 0.2 mT. However, the incoherent MF could not completely eliminate the effects induced by a 0.4 mT 50-Hz MF. Based on the results of this experiment, we conclude that membrane receptors could be one of the main targets where extremely-low frequency (ELF) MF interacts with cells, and the intensity threshold, in the case of EGF receptors, is between 0.05 and 0.1 mT. An incoherent MF could completely inhibit the effects induced by an ELF-MF of equal or lower intensity.

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Interaction of Microwaves and a Temporally Incoherent Magnetic Field on Single and Double DNA Strand Breaks in Rat Brain Cells

Cited by 39 publications

References 17 publications

Superimposition of an Incoherent Magnetic Field Eliminated the Inhibition of Hormone Secretion Induced by a 50-Hz Magnetic Field in Human Villous Trophoblasts <i>in vitro</i>

Superimposition of an Incoherent Magnetic Field Eliminated the Inhibition of Hormone Secretion Induced by a 50-Hz Magnetic Field in Human Villous Trophoblasts <i>in vitro</i>

Electromagnetic fields stress living cells

An Incoherent Magnetic Field Inhibited EGF Receptor Clustering and Phosphorylation Induced by a 50-Hz Magnetic Field in Cultured FL Cells

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