Exposure of nerve growth factor-treated PC12 rat pheochromocytoma cells to a modulated radiofrequency field at 836.55 MHz: Effects on c-jun and c-fos expression

Ivaschuk, Oleg I.; Jones, Robert A.; Ishida-Jones, Tamako; Haggren, Wendy; Adey, W. R.; Phillips, J. E.

doi:10.1002/(sici)1521-186x(1997)18:3<223::aid-bem4>3.0.co;2-4

Cited by 65 publications

(29 citation statements)

References 45 publications

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“…However, despite this general conviction that microwaves are not sufficiently energetic to be able to directly damage DNA, there is considerable evidence indicating that microwaves can be directly and indirectly clastogenic, with a significant increase in chromosome damage (Sagripanti and Swicord, 1986;Garaj-Vrhovac et al, 1991, 1992Maes et al 1993;Haidler et al, 1994;Sarkar et al, 1994;Singh 1995, 1996;Timchenko and Ianchevskaia, 1995;Balode, 1996;Verschaeve et al, 1994;Vijayalaxmi et al, 1997;Phillips et al, 1998;Tice et al, 1999). In addition, cell phone radiation can alter protooncogene activity (Ivaschuk et al, 1997;Goswami et al, 1999). However, a similar number of studies have failed to detect obvious clastogenic effects following microwave irradiation of isolated animal cells in vitro (Alam et al, 1978;Lloyd et al, 1984Lloyd et al, , 1986Wolff et al, 1985;Meltz et al, 1987Meltz et al, , 1989Meltz et al, , 1990Kerbacher et al, 1990;Maes et al, 1997Maes et al, , 2001.…”

Section: Introductioncontrasting

confidence: 68%

Cytogenetic analysis of the effects of 2.5 and 10.5 GHz microwaves on human lymphocytes

2004

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The biological effects of microwaves on living organisms remain highly controversial. Although some reports have suggested that microwaves may be directly or indirectly genotoxic, a direct action is unlikely because the low energy of microwave photons makes them unable to cause single-strand breaks in DNA. In this work, we examined the possible clastogenic properties of microwaves (2.5 and 10.5 GHz) on blood lymphocytes in vitro by monitoring the frequency of chromosomal aberrations. We also investigated whether blood cells showed increased radiosensitivity or radioresistance when pretreated with the microwaves and then irradiated with gamma radiation. There was no significant difference in the frequency of chromosomal aberrations between cells which had or had not been treated with microwaves. Control cells had a mean frequency of 0.013 aberrations per cell compared to 0.010 and 0.011 aberrations per cell in the microwave-exposed samples. Nor was there any alteration in the radiosensitivity of cells pretreated with microwaves. Gamma irradiated cells showed a mean frequency of 0.279 aberrations per cell compared to 0.343 and 0.310 aberrations per cell in samples pretreated with microwaves. However, cell mortality increased markedly after exposure to microwaves. The results suggest that microwaves do not interact directly or indirectly with chromosomes, although they may target other cell structures, such as cell membranes.

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Section: Introductioncontrasting

confidence: 68%

Cytogenetic analysis of the effects of 2.5 and 10.5 GHz microwaves on human lymphocytes

2004

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“…Some reports have suggested that effects caused by increased temperature cannot be ruled out as an explanation of the relationship between HFEMF and adverse outcomes [14,15]. On the other hand, numerous reports have shown that HFEMF exert significant effects under isothermal conditions [16,17,18].…”

Section: Introductionmentioning

confidence: 99%

Effects of 2.45-GHz Electromagnetic Fields with a Wide Range of SARs on Micronucleus Formation in CHO-K1 Cells

Koyama

Isozumi

Suzuki

et al. 2004

The Scientific World JOURNAL

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There has been considerable discussion about the influence of high-frequency electromagnetic fields (HFEMF) on the human body. In particular, HFEMF used for mobile phones may be of great concern for human health. In order to investigate the properties of HFEMF, we have examined the effects of 2.45-GHz EMF on micronucleus (MN) formation in Chinese hamster ovary (CHO)-K1 cells. MN formation is induced by chromosomal breakage or inhibition of spindles during cell division and leads to cell damage. We also examined the influence of heat on MN formation, since HFEMF exposure causes a rise in temperature.CHO-K1 cells were exposed to HFEMF for 2 h at average specific absorption rates (SARs) of 5, 10, 20, 50, 100, and 200 W/kg, and the effects on these cells were compared with those in sham-exposed control cells. The cells were also treated with bleomycin alone as a positive control or with combined treatment of HFEMF exposure and bleomycin. Heat treatment was performed at temperatures of 37, 38, 39, 40, 41, and 42°C.The MN frequency in cells exposed to HFEMF at a SAR of lower than 50 W/kg did not differ from the sham-exposed controls, while those at SARs of 100 and 200 W/kg were significantly higher when compared with the sham-exposed controls. There was no apparent combined effect of HFEMF exposure and bleomycin treatment. On heat treatment at temperatures from 38-42°C, the MN frequency increased in a temperaturedependent manner. We also showed that an increase in SAR causes a rise in temperature and this may be connected to the increase in MN formation generated by exposure to HFEMF.

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“…Four samples were recorded per second for temperature measurement. These characteristics allow measuring a temperature in a volume that can be estimated around 1 and 2 mm 3 . In a previous study, we have estimated a 200-mK standard deviation for the temperature measurement (31), and we have demonstrated the ability of this probe to measure this parameter in small volumes.…”

Section: Methodsmentioning

confidence: 99%

Thermal and Nonthermal Effects of Discontinuous Microwave Exposure (2.45 Gigahertz) on the Cell Membrane of Escherichia coli

Rougier

Prorot

Chazal

et al. 2014

Appl Environ Microbiol

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The aim of this study was to investigate the effects on the cell membranes of Escherichia coli of 2.45-GHz microwave (MW) treatment under various conditions with an average temperature of the cell suspension maintained at 37°C in order to examine the possible thermal versus nonthermal effects of short-duration MW exposure. To this purpose, microwave irradiation of bacteria was performed under carefully defined and controlled parameters, resulting in a discontinuous MW exposure in order to maintain the average temperature of the bacterial cell suspensions at 37°C. Escherichia coli cells were exposed to 200-to 2,000-W discontinuous microwave (DW) treatments for different periods of time. For each experiment, conventional heating (CH) in a water bath at 37°C was performed as a control. The effects of DW exposure on cell membranes was investigated using flow cytometry (FCM), after propidium iodide (PI) staining of cells, in addition to the assessment of intracellular protein release in bacterial suspensions. No effect was detected when bacteria were exposed to conventional heating or 200 W, whereas cell membrane integrity was slightly altered when cell suspensions were subjected to powers ranging from 400 to 2,000 W. Thermal characterization suggested that the temperature reached by the microwave-exposed samples for the contact time studied was not high enough to explain the measured modifications of cell membrane integrity. Because the results indicated that the cell response is power dependent, the hypothesis of a specific electromagnetic threshold effect, probably related to the temperature increase, can be advanced.T he interaction of electromagnetic fields (EMFs) and various life processes has been studied and debated for more than half a century. Identifying and evaluating the biological effects of microwaves (MW) is complex and controversial. Whereas one of the current theories is that heat generation induced by microwaves is responsible for biological effects, there has been a persistent view in the physical and engineering sciences that microwave fields are unable to induce bioeffects other than by heating (1) (2). Because of the scarcity of information on the mechanism of interaction between microwave and biological systems, this controversy endures.A great number of studies of the thermal versus nonthermal bioeffects of low-power MW were performed with various cellular functions, including gene expression (3) and mutation (4), enzyme activity (5), unfolding of proteins (6), biochemical cell systems (7), cell wall (8), cell morphology (9), and cell proliferation (10-13). Whereas several authors showed nonthermal effects, safety standards have been set based solely upon the thermal effect of MW. The main reason was that no satisfactory mechanism was proposed to explain the nonthermal bioeffects.When applied at high power, MW bioeffects induced by heating constitute one of the modern approaches for sterilization and decontamination processes in the food industry. In fact, microwaves have long been known to i...

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Exposure of nerve growth factor-treated PC12 rat pheochromocytoma cells to a modulated radiofrequency field at 836.55 MHz: Effects on c-jun and c-fos expression

Cited by 65 publications

References 45 publications

Cytogenetic analysis of the effects of 2.5 and 10.5 GHz microwaves on human lymphocytes

Cytogenetic analysis of the effects of 2.5 and 10.5 GHz microwaves on human lymphocytes

Effects of 2.45-GHz Electromagnetic Fields with a Wide Range of SARs on Micronucleus Formation in CHO-K1 Cells

Thermal and Nonthermal Effects of Discontinuous Microwave Exposure (2.45 Gigahertz) on the Cell Membrane of Escherichia coli

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