Study type: Medical/biological study (experimental study)

Glioma proliferation modulated in vitro by isothermal radiofrequency radiation exposure med./bio.

By: Cleary SF, Liu LM, Merchant RE
Published in: Radiat Res 1990; 121 (1): 38-45
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Aim of study (acc. to author)

To characterize direct effects of exposure of a human glioma cell line to isothermal radiofrequency radiation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 27 MHz
Modulation type: CW
Exposure duration: continuous for 2 h
  • SAR: 200 mW/g maximum (unspecified)
  • SAR: 5 mW/g minimum (unspecified) (25 W/kg, 50 W/kg, 80 W/kg.)
Exposure 2: 2.45 GHz
Modulation type: CW
Exposure duration: continuous for 2 h
  • SAR: 5 mW/g minimum (unspecified) (25 W/kg, 50 W/kg.)
  • SAR: 74.4 mW/g maximum (unspecified)

General information

Cell suspensions were exposed or sham exposed for 2 h.

Exposure 1

Main characteristics
Frequency 27 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 2 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 200 mW/g maximum unspecified unspecified -
SAR 5 mW/g minimum unspecified unspecified 25 W/kg, 50 W/kg, 80 W/kg.

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 2 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 5 mW/g minimum unspecified unspecified 25 W/kg, 50 W/kg.
SAR 74.4 mW/g maximum unspecified unspecified -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Isothermal exposure of glioma cells in vitro modulated the rates of DNA and RNA synthesis 1, 3, and 5 days after exposure. The alterations indicate effects on cell proliferation and were not caused by radiofrequency-induced cell heating. The dose response for either frequency of the radiation was biphasic: Exposure to SARs of 50 W/kg or less stimulated incorporation rates of [³H]thymidine and [³H]uridine, whereas higher SARs suppressed DNA and RNA synthesis. Statistically significant time-dependent alterations were detected for up to 5 days postexposure, suggesting a kinetic cellular response to radiofrequency exposure and the possibility of cumulative effects on cell proliferation.

Study character:

Study funded by

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