Ornithine decarboxylase activity is affected in primary astrocytes but not in secondary cell lines exposed to 872 MHz RF radiation.
ABSTRACT The effects of radiofrequency (RF) radiation on cellular ornithine decarboxylase (ODC) activity were studied in fibroblasts, two neural cell lines and primary astrocytes. Several exposure times and exposure levels were used, and the fields were either unmodulated or modulated according to the characteristics of the Global System for Mobile (GSM) communications.
Murine L929 fibroblasts, rat C6 glioblastoma cells, human SH-SY5Y neuroblastoma cells, and rat primary astrocytes were exposed to RF radiation at 872 MHz in a waveguide exposure chamber equipped with water cooling. Cells were exposed for 2, 8, or 24 hours to continuous wave (CW) RF radiation or to a GSM type signal pulse modulated at 217 Hz, at specific absorption rates of 1.5, 2.5, or 6.0 W/kg. Cellular ODC activities of cell samples were assayed.
ODC activity in rat primary astrocytes was decreased statistically significantly (p values from 0.003 to <0.001) and consistently in all experiments performed at two exposure levels (1.5 and 6.0 W/kg) and using GSM modulated or CW radiation. In the secondary cell lines, ODC activity was generally not affected.
ODC activity was affected by RF radiation in rat primary neural cells, but the secondary cells used in this study showed essentially no response to similar RF radiation. In contrast to some previous studies, no differences between the modulated and continuous wave signals were detected. Further studies with primary astrocytes are warranted to confirm the present findings and to explore the mechanisms of the effects.
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ABSTRACT: Biological effects of static electric and 50-Hz electric (E) and magnetic (B) fields with intensities similar to occupational exposure have been analyzed at the Bioelectromagnetic Laboratory of Biophysics Department in the Medical Faculty of Gazi University for more than 25 years. A principal aim of this review is to evaluate the results of our in vivo studies. Static electric field in the range of 0.3-1.9 kV/m (0.3, 0.6, 0.8, 0.9, 1.35, 1.8, 1.9 kV/m) and ELF electric field in the range of 1.35-12 kV/m (1.35, 2, 2.5, 3, 3.5, 4, 4.5, 5, 12 kV/m) were applied to lab animals, directions (vertical and horizontal) and exposure periods (4-8 h/day, for 1, 3, 5, 7, 10 days). ELF magnetic fields were also applied with intensities of 1, 1.5, 2, and 3 mT. Magnetic field exposure periods were 4 h/day for 4, 5 or 7 days and 8 h/day for 5 days. Under the above exposure conditions, cellular enzymatic activities (SOD, GSH-Px, MPO, CAT, ADA and XO) and free radicals (MDA and NOx) were analyzed in the plasma, serum and in the tissues of skin, liver, lung, kidney, brain, spleen and testis. Plasma and brain electrolytes such as Na+, Ca++, Mg++, Zn++ and K+ were also studied. Natural Killer cell activity and hydroxyproline content were examined in the skin, brain, lung, spleen and testis tissues under ELF electric and magnetic fields. In addition, Genetic Programming and Neural Network of those tissues were also studied. The results of this study indicated that the changes in lipid peroxidation level (TBARS) and antioxidant enzyme activity (SOD) induced by 50 Hz E-field exposure are higher than those induced by static field. Cellular alterations induced by electromagnetic fields may influence the biochemical reactions in the cell, changing both biochemical parameters and enzyme activities in serum. Our in vivo studies showed that biological responses of plasma and serum were observed to be differentiated under 50 Hz E-field.We observed that 50 Hz ELF E-field seems to be more effective on plasma than on serum. Power frequency (50 Hz/60 Hz) magnetic fields (MFs) can also affect biological systems by activating secondary chemicals such as radicals. ELF EMF has been thought to prolong the life of free radicals and can act as a promoter or co-promoter of cancer. Therefore, ELF MF was classified as a “possible human carcinogen” by The International Agency for Research on Cancer- IARC. In the study, the changes in free radical levels (MDA, NO), antioxidant enzymes (GSH, MPO) and in electrolytes concentrations of various tissues (brain, heart, lung, liver, kidney, plasma) were observed under 50 Hz magnetic fields exposure in different exposure durations. In the light of our results, it can be interpreted that magnitude and exposure durations of electric and magnetic fields may play crucial role in both formation of free radicals and biochemical reactions mediated by free radicals within tissues.Eur. J. Oncol. Library. 01/2010; 5.
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ABSTRACT: It has sometimes been assumed that children are more sensitive than adults to the effects of radiofrequency (RF) fields associated with cellular wireless telephones. However, relatively few in vitro or animal models have examined this possibility. In vitro studies have used several cell types, from both humans and rodents, including primary cells, embryonic cell lines, undifferentiated cancer cell lines, and stem cells. Overall, the balance of evidence does not suggest that field-related effects occur in any cell type: gene and protein expression were not significantly changed by exposure in nine out of 15 studies; genotoxicity was evaluated in 13 papers and in most, of these studies, no damage to DNA was detected; eight studies failed to demonstrate induction of apoptosis; and three studies reported lack of oxidative stress induction by RF-exposures. Five of eight studies investigating the effects of combined exposures to RF fields and chemical or physical agents reported a lack of field-related effects. In addition, few papers have been published on the effects of low level exposure of immature animals. The available results are very limited, both in terms of signals used and biological endpoints investigated, but the evidence does not indicate that prenatal or early postnatal exposures are associated with acute adverse responses or the development of detrimental changes in the long-term. Overall, this suggests that young animals may not be significantly more sensitive than adults, but there is clearly a need for further studies to be carried out.Progress in Biophysics and Molecular Biology 09/2011; 107(3):374-85. · 2.91 Impact Factor
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ABSTRACT: Nowadays, the consumers demand high quality and safety products with "fresh like" taste. Thermal pasteurization is quite efficient in preventing microbial spoilage of food products but the applied heat may also cause undesirable biochemical and nutritious changes which may affect overall quality of the final product. High voltage pulsed electric fields (PEF) treatment, which is an alternative method of pasteurization that do not include aggressive heating, have been investigated in this study, in order to obtain a safe product for human consumption, but with sensory attributes similar to the untreated minimally processed fruits. PEF treatment may inactivate micro-organisms with only a small increase in temperature, simultaneously providing consumers with safe, nutritious, and fresh-like quality foods. PEF treatment is conducted at ambient temperature for a short time (in microseconds), and energy lost due to heating of foods is minimized. In this study the apple puree, prepared from Golden Delicious fruits, was pasteurized using a pulsed electric field (PEF) treatment and stored at chilling temperature, at about 4 o C. During the shelf life of apple puree treated with PEF, color was measured using MiniScan XE Plus (Hunter Lab, USA) spectrocolorimeter. The color parameters were expressed as CIE Lab values, respectively a* -green to red, b* -blue to yellow and L* -black – white indices. This color indicators, also known as tristimulus values, and the reflectance at specific wavelengths, between 400 -700 nm, have been used to express color data. Minimally processed fruits have been popular in Western countries due to convenience and freshness they offer. The purpose of minimal processing is to deliver to the consumer a like-fresh with an extended shelf-life whilst ensuring food safety and maintaining sound nutritional and sensory quality. Generally a shelf life of about 7 days is required for domestic consumption and 7-15 days for overseas consumption.01/2009;