Tian F, Nakahara T, Wake K, Taki M, et al. (2002)
Human glioma M054 cells were exposed to 2.45 GHz at average SARs of 5, 20, 50 and 100 W/kg, using input powers at 0.8, 3.2, 7.8, and 13 W, at a temperature of up to 39°C. The authors used two control groups - one a sham-exposure and the other a temperature control, designed to assess the effect of a high temperature using incubation in a conventional incubator at 39°C. Cell survival and protein levels were assessed at intervals up to 24 hours exposure times.
A slight increase was seen in hsp 70 after exposure at SAR levels of 25 and 78 W/kg for 2 hours. Hsp 70 expression increased with increasing exposure time, except at SAR of 5 W/kg. In the raised temperature control, hsp expression also increased as the incubation time increased, but not as high as that seen with radiation exposure.