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Microwave; B16F10 cell; Fluorescence anisotropy; Cell shape; Cell apoptosis

The paper presents two microwave (MW) exposure systems (MWESs) that permit observations and measurements on cell cultures during their exposure to MW of 2.45 GHz: MWES-1 and MWES-2. MWES-1 is designed for the measurement of the cell membrane fluorescence anisotropies (MFA) simultaneously with MW exposure. MWES-2 is designed for the cells culture exploration under an inverted microscope before, during and after MW exposure. MWES-1 consists mainly of a 2.45 GHz microwave generator (MWG-2.45GHz-SAIREM) of 0-25 W, equipped with forward power and reflected power displaying, and an adjustable coaxial antenna immersed directly into the cuvette with the cells-suspension of a Spex type spectrofluorometer. The MW effect on membrane fluidity of B16F10 malignant melanoma (B16F10-MM) cells in suspension were investigated with MWES-1, by MFA measurements. We observed a MW induced transition temperature (ITT) rising strongly during the MW exposure as compared with ITT obtained by classical heating (CH). The MWES-2 consists of the MWG-2.45 GHz-SAIREM generator and a rectangular waveguide applicator with traveling wave placed between the condenser and the objective of a Zeiss Axiovert 200 microscope, equipped with a fluorescence device and image acquisition. The MW effects on shape and apoptosis of the B16F10-MM cells were investigate with MWES-2. The B16F10-MM cells exhibited visible shape changes during MW exposure up to 37 degrees C. The MW exposure induced cells apoptosis/necrosis in several seconds after that MW are applied, beginning with SAR=1.5 W/sample, compared to CH controls exposed at the same temperature dynamics.

Microwave; Electron beam; Combined exposure; B16F10 cell; C57 BL/6 mouse

The paper presents two radiation exposure facilities (REFs) which permit separate and simultaneous irradiation with microwaves (MW) of 2.45 GHz and electron beams (EB) of 6.23 MeV for malignant melanoma (MM) cell investigations, in vitro (MW+EB-REF-vitro) and in vivo (MW+EB-REF-vivo). The REFs are specifically designed for the following medical studies: 1) The effects of separate and combined (successive and simultaneous) MW and EB irradiation on the B16F10 mouse – MM cell cultures without/with drugs incubation; 2) The effects of separate and combined MW and EB irradiation on human blood components irradiated in samples of integral blood from healthy donors and from donors with MM; 3) The effects of separate and combined MW and EB whole body irradiation on the C57 BL/6 mice bearing MM without/with drugs administration. Several representative results obtained by experiments with REFs in vitro and in vivo are discussed. The most important conclusion of the experimental results is that low dose-total body MW+EB irradiation combined with drugs administration could present a valuable potential for an advanced study in malignant melanoma therapy.

GSM; Fluid-phase endocytosis; Endocytosis inhibitors; Clathrin- and caveolin-covered endosomes; Wire patch exposure cell

We report new data regarding the molecular mechanisms of GSM-induced increase of cell endocytosis rate. Even though endocytosis represents an important physical and biological event for cell physiology, studies on modulated electromagnetic fields (EMF) effects on this process are scarce. In a previous article, we showed that fluid phase endocytosis rate increases when cultured cells are exposed to 900 MHz EMF similar to mobile phones’ modulated GSM signals (217 Hz repetition frequency, 576 micros pulse width) and to electric pulses similar to the GSM electrical component. Trying to distinguish the mechanisms sustaining this endocytosis stimulation, we exposed murine melanoma cells to Lucifer Yellow (LY) or to GSM-EMF/electric pulses in the presence of drugs inhibiting the clathrin- or the caveolin-dependent endocytosis. Experiments were performed at a specific absorption rate (SAR) of 3.2 W/kg in a wire patch cell under homogeneously distributed EMF field and controlled temperature (in the range of 28.5-29.5 degrees C). Thus, the observed increase in LY uptake was not a thermal effect. Chlorpromazine and ethanol, but not Filipin, inhibited this increase. Therefore, the clathrin-dependent endocytosis is stimulated by the GSM-EMF, suggesting that the cellular mechanism affected by the modulated EMF involves vesicles that detach from the cell membrane, mainly clathrin-coated vesicles.

Mitosis; Fluid phase endocytosis; Phase contrast microscopy; TEM cell; GSM-EMF

Studying cell behaviour under irradiation with radiofrequency electromagnetic fields (RF-EMF) is often impeded by the difficulty to monitor cell characteristics during irradiation. Here we report the design and the application of a complete device for continuous microscopic observation of cells exposed to modulated EMF similar to mobile phones signals. The system allows the follow up of cell progression into mitosis under controlled temperature and CO(2) environment. Protocols are proposed in which the same cells are the controls before and after the EMF exposure and we demonstrate the interest of the “before exposure” controls. The exposure system was validated by cell endocytosis measurements. While the endocytosis rate was increased, no alteration of mitosis progression and mitosis duration was observed in cells exposed to 900 MHz modulated EMF for 1 h, at 30 degrees C and at a Specific Absorption Rate of 2.2 W/kg.