Dynamic changes in cytoskeleton proteins of olfactory ensheathing cells induced by radiofrequency electromagnetic fields.

Several evidences have suggested the ability of radiofrequency electromagnetic fields to influence biological systems, even if the action mechanisms are not well understood. There are few data on the effect of radiofrequency electromagnetic fields on self-renewal of neural progenitor cells. A particular glial type that shows characteristics of stem cells is olfactory ensheathing cells (OECs). Herein, we assessed the non-thermal effects induced on OECs through radiofrequency electromagnetic fields changing the envelope of the electromagnetic wave. Primary OEC cultures were exposed to continuous or amplitude-modulated 900 MHz electromagnetic fields, in the far-field condition and at different exposure times (10, 15, 20 min). The expression of OEC markers (S-100 and nestin), cytoskeletal proteins (GFAP and vimentin), apoptotic pathway activation by caspase-3 cleavage and cell viability were evaluated. Our results highlight that 20 min of exposure to continuous or amplitude-modulated 900 MHz electromagnetic fields induced a different and significant decrease in cell viability. In addition, according to the electromagnetic field waveform, diverse dynamic changes in the expression of the analysed markers in OECs and activation of the apoptotic pathway were observed. The data suggest that radiofrequency electromagnetic fields might play different and important roles in the self-renewal of OEC stem cells, which are involved in nervous system repair.

Impact of structure on the delayed luminescence of d-Glucose-based polymer chains.

Glucose is a natural chemical compound and is one of the most abundant organic molecules in nature. Plants and algae are able to produce it from water and carbon dioxide during photosynthesis, using energy of photons coming from the sun. It is very important in life processes because, in energy metabolism, Glucose is the most important source of energy in all organisms. As energy reservoir it is partially stored as a polymer, in plants mainly as starch and amylopectin and in animals as glycogen. Moreover it is used as cellulose, the most abundant carbohydrate, to strengthen plants and algae cell walls. In this paper we study the Delayed Luminescence from Glucose and its polymers, Amylose and Cellulose, composed by chains of glucose connected by different bond, as well as Glucose water solution, in order to acquire new knowledge on the mechanisms responsible for this phenomenon and check the possibility to give in-depth analysis of possible collective states present in Glucose-based structures. The phenomenon of DL in biological systems is not a byproduct, as one can naively expect. Instead, it is a property and necessity of the condensed matter, which can be also used as a tool to study the latter. It is a manifestation of the physical and biochemical processes in the system, on one hand side, and, on the other hand side, of its structural properties, in particular, of the presence and type of crystal-like structure, resulting in specific energy spectrum and electron transitions, as will be presented below. We show that the quantum yield and time trends of the Delayed Luminescence depend on the structure of systems under study. Significant differences in Delayed Luminescence parameters from cellulose before and after imbibition have been observed, indicating that Delayed Luminescence could be used to discriminate between various structures and follow the formation or demolition of them. The experimental results qualitatively agree with the soliton mechanism of the Delayed luminescence.

Delayed luminescence: a novel technique to obtain new insights into water structure.

Fully understanding the structure of water is a crucial point in biophysics because this liquid is essential in the operation of the engines of life. Many of its amazing anomalies seem to be tailored to support biological processes and, during about a century, several models have been developed to describe the water structuring. In particular, a theory assumes that water is a mixture of domains constituted by two distinct and inter-converting structural species, the low-density water (LDW) and the high-density water (HDW). According to this theory, by using some particular solutes or changing the water temperature, it should be possible to modify the equilibrium between the two species, changing in this way the water behavior in specific biological processes, as in governing the shape and stability of the structures of proteins. In this work, we assess the possibility of obtaining information on the structures induced in water by specific salts or by temperature by measuring the delayed luminescence (DL) of some salt solutions and of water in the super-cooled regime. Previous works have demonstrated that the delayed luminescence of a system is correlated with its dynamic ordered structures. The results show significant DL signals only when the formation of LDW domains is expected. The measurement reveals a similar activation energy for the domains both in aqueous salt solutions and super-cooled water. It is worth noting that the time trend of DL signals suggests the existence of structures unusually long-lasting in time, up to the microsecond range.

Reactive oxygen species levels and DNA fragmentation on astrocytes in primary culture after acute exposure to low intensity microwave electromagnetic field.

The exposure of primary rat neocortical astroglial cell cultures to acute electromagnetic fields (EMF) in the microwave range was studied. Differentiated astroglial cell cultures at 14 days in vitro were exposed for 5, 10, or 20min to either 900MHz continuous waves or 900MHz waves modulated in amplitude at 50Hz using a sinusoidal waveform and 100% modulation index. The strength of the electric field (rms value) at the sample position was 10V/m. No change in cellular viability evaluated by MTT test and lactate dehydrogenase release was observed. A significant increase in ROS levels and DNA fragmentation was found only after exposure of the astrocytes to modulated EMF for 20min. No evident effects were detected when shorter time intervals or continuous waves were used. The irradiation conditions allowed the exclusion of any possible thermal effect. Our data demonstrate, for the first time, that even acute exposure to low intensity EMF induces ROS production and DNA fragmentation in astrocytes in primary cultures, which also represent the principal target of modulated EMF. Our findings also suggest the hypothesis that the effects could be due to hyperstimulation of the glutamate receptors, which play a crucial role in acute and chronic brain damage. Furthermore, the results show the importance of the amplitude modulation in the interaction between EMF and neocortical astrocytes.

Corresponding measurements of delayed luminescence and impedance spectroscopy on acupuncture points.

Measurements of impedance spectroscopy and delayed luminescence have been performed on the acupuncture points PC4 and PC8 and other two control points of ten volunteers. The results show that there is a highly significant difference between the imaginary parts of the impedance of the acupunctural points and that of the control points. The same difference has not be observed in the values of the total number of counts of delayed luminescence. However a relationship has been detected between the imaginary part of the impedance of PC8 point and the total number of delayed luminescence counts, similar to that one found before for collagen, and it has been seen that the temporal dynamics of the two phenomena measured on one control points are similar. In particular, these final results confirm the close connection between the delayed luminescence and the dielectric properties of biological tissues.

Nonlinear dependence of the delayed luminescence yield on the intensity of irradiation in the framework of a correlated soliton model.

We generalize the correlated soliton model in order to describe the delayed luminescence arising from biological systems after their exposition to the irradiation by relatively high dose (high intensity and/or long duration of irradiation). The quantum yield of the delayed luminescence is calculated as a function of the irradiation and is shown to depend nonlinearly on the intensity and dose of the irradiation. At relatively low intensity, the yield of luminescence increases with increasing dose, and monotonously reaches saturation. At high intensity of the irradiation, the yield of the photosystem under study is restricted from above by the concentration of photosystem units. As a result, the total yield of the delayed luminescence first increases with the dose till the maximum value that, in the general case, is less than the maximum number of available photosystem units. With further increase of the dose, the yield gradually decreases, reaching the saturation value at large dose of illumination. These results are obtained within the steady state approximation in the description of the luminescence kinetics. To check the applicability of this approximation at high levels and large time of illumination, the corrections to the steady state solution have been calculated, and shown to decrease exponentially with increase in time till the small finite constant value. The results of the theoretical model are shown to describe well the experimental data on the dose dependence of the quantum yield of the luminescence of algae Acetabularia acetabulum, for which the correlated soliton model describes well the kinetics of the delayed luminescence at low levels of irradiation.

Solid state approach in biophoton research.

Main characteristics of the delayed luminescence (DL) emitted in the seconds range from biological systems is analyzed. The correlation between change in DL and cell's organization, and similarity with some characteristics of DL from solid state system suggest to connect DL in biological system to decay of collective electron states, formed during energy and charge transport along the macromolecular ordered structures which form the cell. Results of a proposed soliton model are discussed, together with some phenomenological evidence which emphasize the possibility of using DL measurements as an intrinsic probe in biophysical investigations.