Study type: Medical/biological study (experimental study)

Induction of neoplastic transformation in C3H/10T1/2 cells by 2.45 GHz microwaves and phorbol ester med./bio.

By: Balcer-Kubiczek EK, Harrison GH
Published in: Radiat Res 1989; 117 (3): 531-537
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Aim of study (acc. to editor)

To study transformation frequency and cell survival with or without postirradiation addition of the tumor promoter TPA in C3H 10T1/2 cells exposed to 2.45 GHz microwaves and/or X-rays.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: pulsed
Exposure duration: continuous for 24 h

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Charakteristic
Exposure duration continuous for 24 h
Modulation
Modulation type pulsed
Pulse width 83 µs
Repetition frequency 120 Hz
Exposure setup
Exposure source
Chamber The exposure facility has previously been described in detail [Harrison et al., 1985].
Setup Three 25-cm² cell-culture flasks filled with medium were placed horizontally and cell-side down beneath a quarter-wave transformer covering the central 25 x 25 cm region of a large (60 x 60 x 12 cm) constant-temperature (37.2 ± 0.1°C) water bath with their cellular attachment plane approx. 3 cm below water level. Two flasks for sham exposure were placed inside a grounded copper-mesh enclosure located at the bottom, peripheral to the central region.
Sham exposure A sham exposure was conducted.
Additional info Cells were exposed to MW only, or they were pre- or post-irradiated with 1.5 Gy of 238-kVp X rays. Additional groups were sham exposed or exposed to X rays only. It is not really clear from the article whether or when the latter group was also sham exposed.
Parameters
Measurand Value Type Method Mass Remarks
power 1 kW peak value measured - forward power to the antenna
SAR 4.4 W/kg mean measured - ± 0.8 W/kg
Measurement and calculation details

The bulk temperature in the flasks and forward power to the antenna were monitored continuously. The SAR at the cell monolayer has been determined previously from calorimetric and field measurements using a three-dimensional EF probe [Harrison et al., 1985].

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

A statistically significant enhancement of transformation response by TPA in cells exposed to 2.45 GHz microwaves is shown. Microwaves alone had no effect on cell transformation. Plating efficiency and cell survival were not affected by TPA or microwaves.

Study character:

Study funded by

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