CT2A Cell Viability Modulated by Electromagnetic Fields at Extremely Low Frequency under No Thermal Effects

The effects produced by electromagnetic fields (EMFs) on human beings at extremely low frequencies (ELFs) have being investigated in the past years, across in vitro studies, using different cell lines. Nevertheless, the effects produced on cells are not clarified, and the cellular mechanisms and cell-signaling processes involved are still unknown. This situation has resulted in a division among the scientific community about the adequacy of the recommended level of exposure. In this sense, we consider that it is necessary to develop long-term exposure studies and check if the recommended levels of EMFs are under thermal effects. Hence, we exposed CT2A cells to different EMFs at different ELFs at short and long times. Our results showed frequency dependence in CT2A exposed during 24 h to a small EMF of 30 μT equal to those originated by the Earth and frequency dependence after the exposure during seven days to an EMF of 100 µT at different ELFs. Particularly, our results showed a remarkable cell viability decrease of CT2A cells exposed to EMFs of 30 Hz. Nevertheless, after analyzing the thermal effects in terms of HSP90 expression, we did not find thermal damages related to the differences in cell viability, so other crucial cellular mechanism should be involved.

Download Full-text

Significant Cellular Viability Dependence on Time Exposition at ELF-EMF and RF-EMF In Vitro Studies

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16122085 ◽

2019 ◽

Vol 16 (12) ◽

pp. 2085 ◽

Cited By ~ 3

Author(s):

Olga García-Minguillán López ◽

Ana Jiménez Valbuena ◽

Ceferino Maestú Unturbe

Keyword(s):

Cell Viability ◽

Electromagnetic Fields ◽

New Technologies ◽

Time Dependent ◽

Cellular Viability ◽

Low Frequencies ◽

Dependent Effect ◽

Time Dependent Effect ◽

Over Time

The human concern about the effect of electromagnetic fields (EMFs) has changed over time from the effects produced by EMFs of extremely low frequencies (ELFs) to the effects produced by exposure to a radio frequency (RF), with concerns shifting toward EMFs due to the development of new technologies and forms of communication. Previous studies have analysed the effects produced at different frequencies without considering in detail the effect of the time of exposure. Therefore, in the present study, we analysed in vitro the effect produced by a 100 µT EMF at different ELFs and exposure times in glioblastomas, as well as the effect produced in a fibroblast by an RF-EMF of 2.54 GHz. Our results indicate a significant time dependence in cell viability of fibroblasts exposed to an RF-EMF of 2.54 GHz and a non-time-dependent effect in cell viability of glioblastomas exposed to an ELF-EMF, highlighting the possible relation between frequency and time of exposure.

Download Full-text

Effects Induced “in vitro” by Extremely Low Frequency Electromagnetic Fields (E.L.F.) on Blastogenesis of Human Lymphocytes and on Thromboxane B-2-Release by Ionophore-Stimulated Neutrophils

Biological Effects and Dosimetry of Static and ELF Electromagnetic Fields ◽

10.1007/978-1-4613-2099-9_20 ◽

1985 ◽

pp. 335-338 ◽

Cited By ~ 1

Author(s):

P. Conti ◽

G. E. Gigante ◽

M. G. Cifone ◽

E. Alesse ◽

M. Reale ◽

...

Keyword(s):

Electromagnetic Fields ◽

Human Lymphocytes ◽

Low Frequency ◽

Extremely Low Frequency

Download Full-text

Human Gingival Fibroblasts Exposed to Extremely Low-Frequency Electromagnetic Fields: In Vitro Model of Wound-Healing Improvement

International Journal of Molecular Sciences ◽

10.3390/ijms20092108 ◽

2019 ◽

Vol 20 (9) ◽

pp. 2108 ◽

Cited By ~ 3

Author(s):

Erica Costantini ◽

Bruna Sinjari ◽

Chiara D’Angelo ◽

Giovanna Murmura ◽

Marcella Reale ◽

...

Keyword(s):

Wound Healing ◽

Electromagnetic Field ◽

Electromagnetic Fields ◽

Wound Repair ◽

Healing Process ◽

Low Frequency ◽

Gingival Fibroblasts ◽

Field Exposure ◽

Extremely Low Frequency

Several clinical studies have suggested the impact of sinusoidal and pulsed electromagnetic fields in quickening wound repair processes and tissue regeneration. The clinical use of extremely low-frequency electromagnetic fields could represent a novel frontier in tissue repair and oral health, with an interesting clinical perspective. The present study aimed to evaluate the effect of an extremely low-frequency sinusoidal electromagnetic field (SEMF) and an extremely low-frequency pulsed electromagnetic field (PEMF) with flux densities of 1 mT on a model of oral healing process using gingival fibroblasts. An in vitro mechanical injury was produced to evaluate wound healing, migration, viability, metabolism, and the expression of selected cytokines and protease genes in fibroblasts exposed to or not exposed to the SEMF and the PEMF. Interleukin 6 (IL-6), transforming growth factor beta 1 (TGF-β), metalloproteinase 2 (MMP-2), monocyte chemoattractant protein 1 (MCP-1), inducible nitric oxide synthase (iNOS), and heme oxygenase 1 (HO-1) are involved in wound healing and tissue regeneration, favoring fibroblast proliferation, chemotaxis, and activation. Our results show that the exposure to each type of electromagnetic field increases the early expression of IL-6, TGF-β, and iNOS, driving a shift from an inflammatory to a proliferative phase of wound repair. Additionally, a later induction of MMP-2, MCP-1, and HO-1 was observed after electromagnetic field exposure, which quickened the wound-healing process. Moreover, electromagnetic field exposure influenced the proliferation, migration, and metabolism of human gingival fibroblasts compared to sham-exposed cells. This study suggests that exposure to SEMF and PEMF could be an interesting new non-invasive treatment option for wound healing. However, additional studies are needed to elucidate the best exposure conditions to provide the desired in vivo treatment efficacy.

Download Full-text

Low-frequency respiratory mechanical impedance in the rat

Journal of Applied Physiology ◽

10.1152/jappl.1987.63.1.36 ◽

1987 ◽

Vol 63 (1) ◽

pp. 36-43 ◽

Cited By ~ 40

Author(s):

Z. Hantos ◽

B. Daroczy ◽

B. Suki ◽

S. Nagy

Keyword(s):

Frequency Dependence ◽

Chest Wall ◽

Low Frequency ◽

Mechanical Impedance ◽

Total Resistance ◽

Low Frequencies ◽

Chest Wall Compliance ◽

Before And After ◽

Airway Opening ◽

Wall Compliance

modified forced oscillatory technique was used to determine the respiratory mechanical impedances in anesthetized, paralyzed rats between 0.25 and 10 Hz. From the total respiratory (Zrs) and pulmonary impedance (ZL), measured with pseudorandom oscillations applied at the airway opening before and after thoracotomy, respectively, the chest wall impedance (ZW) was calculated as ZW = Zrs - ZL. The pulmonary (RL) and chest wall resistances were both markedly frequency dependent: between 0.25 and 2 Hz they contributed equally to the total resistance falling from 81.4 +/- 18.3 (SD) at 0.25 Hz to 27.1 +/- 1.7 kPa.l–1 X s at 2 Hz. The pulmonary compliance (CL) decreased mildly, from 2.78 +/- 0.44 at 0.25 Hz to 2.36 +/- 0.39 ml/kPa at 2 Hz, and then increased at higher frequencies, whereas the chest wall compliance declined monotonously from 4.19 +/- 0.88 at 0.25 Hz to 1.93 +/- 0.14 ml/kPa at 10 Hz. Although the frequency dependence of ZW can be interpreted on the basis of parallel inhomogeneities alone, the sharp fall in RL together with the relatively constant CL suggests that at low frequencies significant losses are imposed by the non-Newtonian resistive properties of the lung tissue.

Download Full-text

Induction of Cell Activation Processes by Low Frequency Electromagnetic Fields

The Scientific World JOURNAL ◽

10.1100/tsw.2004.174 ◽

2004 ◽

Vol 4 ◽

pp. 4-22 ◽

Cited By ~ 33

Author(s):

Myrtill Simkó

Keyword(s):

Electromagnetic Fields ◽

Cellular Response ◽

Cell Activation ◽

Childhood Leukemia ◽

Mechanistic Model ◽

Cell Cycle Control ◽

Low Frequency ◽

Cellular Systems ◽

Increased Risk

Electromagnetic fields (EMF) such as those from electric power transmission and distribution lines (50/60 Hz) have been associated with increased risk of childhood leukemia, cancer of the nervous system, and lymphomas. Severalin vitrostudies on EMF effects were performed to clarify the existing controversies, define the risks, and determine the possible mechanisms of adverse effects. In some of these reports, the effects were related to other mechanisms of carcinogenesis. Modification in cell proliferation was observed after EMF exposure and a few reports on cytotoxic effects have also been published. This limited review gives an overview of the current results of scientific research regardingin vitrostudies on the effects of power line frequency EMF, but also cell biological mechanisms and their potential involvement in genotoxicity and cytotoxicity are discussed. Cell cycle control and signal transduction processes are included to elucidate the biochemical background of possible interactions. Exposure to EMF has been also linked to the incidence of leukemia and other tumors in some epidemiological studies and is considered as “possibly carcinogenic to humans”, but there is no well-established biological mechanism that explains such a relation. Furthermore, EMF is also shown as a stimulus for immune relevant cells (e.g., macrophages) to release free radicals. It is known that chronic activation of macrophages is associated with the onset of phagocytosis and leads to increased formation of reactive oxygen species, which themselves may cause DNA damage and are suggested to lead to carcinogenesis. To demonstrate a possible interaction between EMF and cellular systems, we present a mechanistic model describing cell activation as a major importance for cellular response.

Download Full-text

Low-frequency electromagnetic fields induce premature terminal differentiation of in-vitro cultured human skin and lung fibroblasts

Journal of Electroanalytical Chemistry ◽

10.1016/0022-0728(92)85121-i ◽

1992 ◽

Vol 342 (3) ◽

pp. 269-280 ◽

Cited By ~ 3

Author(s):

H.Peter Rodemann ◽

Petra Wecke ◽

Monika Jaeschke

Keyword(s):

Human Skin ◽

Electromagnetic Fields ◽

Low Frequency ◽

Terminal Differentiation ◽

Lung Fibroblasts

Download Full-text

Effect of extremely low frequency electromagnetic fields on thromboxane B2-release by ionophore-stimulated neutrophils in vitro

Prostaglandins ◽

10.1016/0090-6980(84)90341-1 ◽

1984 ◽

Vol 27 ◽

pp. 96 ◽

Cited By ~ 1

Author(s):

P. Conti ◽

G.E. Gigante ◽

M.G. Cifone ◽

E. Alesse ◽

G. Ianni ◽

...

Keyword(s):

Electromagnetic Fields ◽

Low Frequency ◽

Thromboxane B2 ◽

Extremely Low Frequency

Download Full-text

Differential Modulation of Neural Network and Pacemaker Activity Underlying Eupnea and Sigh-Breathing Activities

Journal of Neurophysiology ◽

10.1152/jn.01192.2007 ◽

2008 ◽

Vol 99 (5) ◽

pp. 2114-2125 ◽

Cited By ~ 71

Author(s):

Andrew K. Tryba ◽

Fernando Peña ◽

Steven P. Lieske ◽

Jean-Charles Viemari ◽

Muriel Thoby-Brisson ◽

...

Keyword(s):

Low Frequency ◽

Network Activity ◽

Pacemaker Activity ◽

Differential Modulation ◽

Multiple Frequency ◽

Low Frequencies ◽

Respiratory Network ◽

Bötzinger Complex ◽

Amplitude Characteristics

Many networks generate distinct rhythms with multiple frequency and amplitude characteristics. The respiratory network in the pre-Bötzinger complex (pre-Böt) generates both the low-frequency, large-amplitude sigh rhythm and a faster, smaller-amplitude eupneic rhythm. Could the same set of pacemakers generate both rhythms? Here we used an in vitro respiratory brainslice preparation. We describe a subset of synaptically isolated pacemakers that spontaneously generate two distinct bursting patterns. These two patterns resemble network activity including sigh-like bursts that occur at low frequencies and have large amplitudes and eupneic-like bursts with higher frequency and smaller amplitudes. Cholinergic neuromodulation altered the network and pacemaker bursting: fictive sigh frequency is increased dramatically, whereas fictive eupneic frequency is drastically lowered. The data suggest that timing and amplitude characteristics of fictive eupneic and sigh rhythms are set by the same set of pacemakers that are tuned by changes in the neuromodulatory state.

Download Full-text