RESUMO
The mode of action of a huge amount of agents on biological systems is still unknown. One example where more questions than answers exist is covered by the term electromagnetic fields (EMF). Use of wireless communication, e.g. mobile phones, has been escalated in the last few years. Due to this fact, a lot of discussions dealt with health consequences of EMF emitted by these devices and led to an increased investigation of their effects to biological systems, mainly by using traditional methods. Omics technologies have the advantage to contain methods for investigations on DNA-, RNA- and protein level as well as changes in the metabolism.This literature survey is an overview of the available scientific publications regarding biological and health effects of EMF and the application of new high-throughput technologies. The aim of the study was to analyse the amount and the distribution of these technologies and to evaluate their relevance to the risk analysis of EMF. At present, only transcriptomics is able to analyse almost all of the specific molecules. In comparison to ionising radiation, fewer articles dealt with health effects of EMF. Interestingly, most of the EMF articles came from European institutions.Although omics techniques allow exact and simultaneous examinations of thousands of genes, proteins and metabolites in high-throughput technologies, it will be an absolute prerequisite to use standardised protocols and to independently validate the results for comparability and eventually for sound standing statements concerning possible effects of agents like EMF on biological systems.
RESUMO
In the present paper, the induction of calcium signals in neuroblastoma cells, cells of T-cell leukemia, and osteogenic sarcoma cells were investigated in relation to the UVA irradiation used in fluorescence microscopy. Methods were developed to measure both the mean UVA irradiance and the intensity profile in the UVA-illuminated area of the microscope. This allowed us to calculate the applied UVA radiant exposure of the cells during each experiment. This investigation was undertaken because of the conflicting results in the literature on the effects of electromagnetic fields on the signals of the calcium-sensitive fluorescence probe FURA-2 in lymphocytes. Taking into account that each group used a different system with different optics and lamps, these conflicting results are now at least partially understandable. Our measurements indicate that in a typical experiment with FURA-2 the cells were irradiated with up to 776 kJ m(-2) during 25 min of exposure to UVA light. This causes changes in intracellular free Ca(2+) concentrations ([Ca(2+)](i)). Designating cells in which the [Ca(2+)](i) was distinctly increased during the experiment as "responding", we found Hill-type dependences on the irradiance. Jurkat cells showed a 50% response even at 10 kJ m(-2) and osteosarcoma cells at about 60 kJ m(-2), whereas neuroblastoma cells even at the maximum possible dose responded only minimally. In the case of neuroblastoma cells, we found a dependence of this effect on the CO(2) partial pressure during the preincubation. An electrical treatment with an a.c. field (5 kHz sinusoidal, amplitude modulation 16 Hz 100%, 800 V m(-1), 5 min) had a significant effect on intracellular calcium in neuroblastoma cells only in the case of cells that were not pretreated with CO(2) with high fluences of UVA irradiation. In conclusion, these results indicate that the possibility of UVA artifacts must be considered in all experiments using fluorescence microscopy. Furthermore, our results lead to the hypothesis that oxidative stress could be the link between UVA and electric-field effects.
