Elsa Moggia

Bio: Elsa Moggia is an academic researcher from University of Genoa. The author has contributed to research in topics: Osmotic coefficient & Activity coefficient. The author has an hindex of 10, co-authored 24 publications receiving 286 citations. Previous affiliations of Elsa Moggia include University of Bergen.

Zeeman-Stark modeling of the RF EMF interaction with ligand binding.

Abstract: The influence of radiofrequency electromagnetic exposure on ligand binding to hydrophobic receptor proteins is a plausible early event of the interaction mechanism. A comprehensive quantum Zeeman-Stark model has been developed which takes into account the energy losses of the ligand ion due to its collisions inside the receptor crevice, the attracting nonlinear endogenous force due to the potential energy of the ion in the binding site, the out of equilibrium state of the ligand-receptor system due to the basal cell metabolism, and the thermal noise. The biophysical "output" is the change of the ligand binding probability that, in some instances, may be affected by a suitable low intensity exogenous electromagnetic "input" exposure, e.g., if the depth of the potential energy well of a putative receptor protein matches the energy of the radiofrequency photon. These results point toward both the possibility of the electromagnetic control of biochemical processes and the need for a new database of safety standards.

Effect of lifetimes on ligand binding modelled by the density operator

Abstract: This paper addresses the problem of evaluating theoretically the effects of electromagnetic (EM) exposure on biological systems. EM fields can affect the chemical activity of ions while they interact with the membrane receptors of a cell during a binding process. A coulombic three-state Zeeman model for the binding site is proposed, and the ion adsorption under low-frequency magnetic exposure is described by means of the density operator. The system interactions with the thermal bath are accounted for by a suitable set of lifetime parameters. The limits of a first-order perturbation approach, which allows us to find a closed-form expression for the ion-binding probability, are discussed. The biological effectiveness of a Helmholtz coil exposure system is rather small if computed according to the simplifying assumptions of the paper.

Mean Activity Coefficient of Electrolyte Solutions

Abstract: In this paper, we deal with the mean activity coefficient, γ, of electrolyte solutions. The case γ ≤ 1 is investigated. As is generally recognized, the most accepted models (specific ion interaction/Pitzer theory) have the disadvantage of the dependence on semiempirical parameters. These are not directly accessible from experimental measurements, but can only be estimated by means of best-fitting numerical techniques from experimental data. In the general context of research devoted to the achievement of some reduction of complexity, we propose a model of electrolyte solution that allows us to calculate γ without using fitting parameters where the (upper) concentration exists at which the electrolyte solution exhibits γ = 1 (molality scale). In the remaining cases, we show that a unique parameter is required, that is, the concentration that should ideally give γ = 1 for the electrolyte. Compared to other models that do not require adjustable parameters, the present one is generally applicable over a wider...

Effects of a 50 Hz magnetic field on Dictyostelium discoideum (Protista)

Abstract: Some studies have demonstrated that a few biological systems are affected by weak, extremely low frequency (ELF) electromagnetic fields (EMFs), lower than 10 mT. However, to date there is scanty evidence of this effect on Protists in the literature. Due to their peculiarity as single-cell eukaryotic organisms, Protists respond directly to environmental stimuli, thus appearing as very suitable experimental systems. Recently, we showed the presence of propionylcholinesterase (PrChE) activity in single-cell amoebae of Dictyostelium discoideum. This enzyme activity was assumed to be involved in cell-cell and cell-environment interactions, as its inhibition affects cell aggregation and differentiation. In this work, we have exposed single-cell amoebae of D. discoideum to an ELF-EMF of about 200 microT, 50 Hz, for 3 h or 24 h at 21 degrees C. A delay in the early phase of the differentiation was observed in 3 h exposed cells, and a significant decrease in the fission rate appeared in 24 h exposed cells. The PrChE activity was significantly lower in 3 h exposed cells than in the controls, whereas 24 h exposed cells exhibited an increase in this enzyme activity. However, such effects appeared to be transient, as the fission rate and PrChE activity values returned to the respective control values after a 24 h stay under standard conditions.

Fokker–Planck analysis of the Langevin–Lorentz equation: Application to ligand-receptor binding under electromagnetic exposure

Abstract: The statistical properties of the solution of the Langevin–Lorentz equation are analyzed by means of the Fokker–Planck approach. The equation describes the dynamics of an ion that is attracted by a central field and is interacting with a time-varying magnetic field and with the thermal bath. If the endogenous force is assumed to be elastic, then a closed-form expression for the probability density of the process can be obtained, in the case of constant magnetic exposure and, for the time-varying case, at least asymptotically. In the general case, a numerical integration of the resulting set of differential equations with periodically time-varying coefficients has been implemented. A framework for studying the possible effects of low-frequency, low-intensity electromagnetic fields on biological systems has been developed on the basis of the equation. The model assumes that an exogenous electromagnetic field may affect the binding of a messenger attracted by the endogenous force field of its receptor protein. The results are applicable to the analysis of experiments, e.g., exposing a Petri dish, containing a biological sample, to a periodically time-varying magnetic field generated by a pair of Helmholtz coils, most widely used in the scientific literature. The proposed model provides a theoretical mean for evaluating the biological effectiveness of low-frequency, low-intensity electromagnetic exposure.

Mechanism for action of electromagnetic fields on cells.

Abstract: A biophysical model for the action of oscillating electric fields on cells, presented by us before [Biochem. Biophys. Res. Commun. 272(3) (2000) 634-640], is extended now to include oscillating magnetic fields as well, extended to include the most active biological conditions, and also to explain why pulsed electromagnetic fields can be more active biologically than continuous ones. According to the present theory, the low frequency fields are the most bioactive ones. The basic mechanism is the forced-vibration of all the free ions on the surface of a cell's plasma membrane, caused by an external oscillating field. We have shown that this coherent vibration of electric charge is able to irregularly gate electrosensitive channels on the plasma membrane and thus cause disruption of the cell's electrochemical balance and function [Biochem. Biophys. Res. Commun. 272(3) (2000) 634-640]. It seems that this simple idea can be easily extended now and looks very likely to be able to give a realistic basis for the explanation of a wide range of electromagnetic field bioeffects.

Stimulation of growth factor synthesis by electric and electromagnetic fields.

Abstract: Biophysical input, including electric and electromagnetic fields, regulate the expression of genes in connective tissue cells for structural extracellular matrix (ECM) proteins resulting in an increase in cartilage and bone production. In in vivo models and clinical situations, this can be manifested as enhanced repair and a gain in mechanical properties of the repairing tissues. The mechanisms by which cell functions are regulated by biophysical input is the subject of this review. Biophysical interactions of electric and electromagnetic fields at the cell membrane are not well understood and require considerable additional study. We review information on transmembrane signaling, channel activation and receptor stimulation or blockade. Understanding physical interactions and transmembrane signaling will most likely be necessary to establish dosing paradigms and improve therapeutic efficacy. Considerable information has been generated on an intermediary mechanism of activity - growth factor stimulation. Electric and electromagnetic fields increase gene expression for, and synthesis of, growth factors and this may function to amplify field effects through autocrine and paracrine signaling. Electric and electromagnetic fields can produce a sustained upregulation of growth factors, which enhance, but do not disorganize endochondral bone formation. Progress in the areas of signal transduction and growth factor synthesis is very rapid and future directions are suggested.

Clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems

Abstract: Theoretical models proposed to date have been unable to clearly predict biological results from exposure to low-intensity electric and magnetic fields (EMF). Recently a predictive ionic resonance model was proposed by Lednev, based on an earlier atomic spectroscopy theory described by Podgoretskii and Podgoretskii and Khrustalev. The ion parametric resonance (IPR) model developed in this paper corrects mathematical errors in the earlier Lednev model and extends that model to give explicit predictions of biological responses to parallel AC and DC magnetic fields caused by field-induced changes in combinations of ions within the biological system. Distinct response forms predicted by the IPR model depend explicitly on the experimentally controlled variables: magnetic flux densities of the AC and DC magnetic fields (Bac and Bdc, respectively); AC frequency (fac); and, implicitly, charge to mass ratio of target ions. After clarifying the IPR model and extending it to combinations of different resonant ions, this paper proposes a basic set of experiments to test the IPR model directly which do not rely on the choice of a particular specimen or endpoint. While the fundamental bases of the model are supported by a variety of other studies, the IPR model is necessarily heuristic when applied to biological systems, because it is based on the premise that the magnitude and form of magnetic field interactions with unhydrated resonant ions in critical biological structures alter ion-associated biological activities that may in turn be correlated with observable effects in living systems. © 1994 Wiley-Liss, Inc.

Mechanisms for interaction between RF fields and biological tissue.

Abstract: Interaction of radiofrequency (RF) fields with biological tissue can involve either electric or magnetic fields. Many interaction mechanisms have been considered, both thermal and nonthermal, but it has not been established that any of these could result in adverse health effects at radiation levels below guidelines. The principles underlying most of these mechanisms have been well reviewed. The aim of the present study is to give a qualitative discussion of some of the more recently published work.

The Role of Electrical Stimulation in Bone Repair

Abstract: Electric and electromagnetic fields regulate extra-cellular matrix synthesis and stimulate repair of fractures and nonunions. Studies of electric and electromagnetic fields suggest they (1) regulate proteoglycan and collagen synthesis and increase bone formation in models of endochondral ossification, (2) accelerate bone formation and repair, (3) increase union rates in fractures previously refractory to healing, and (4) produce results equivalent to bone grafts. Electric and electromagnetic fields regulate the expression of genes in connective tissue cells for extra-cellular matrix proteins, which results in an increase in cartilage and bone. They also increase gene expression for and synthesis of growth factors, which may be an intermediary mechanism of activity and may amplify field effects through autocrine and paracrine signaling.