Effects Of Millimeter-wave Radiation Research Articles

Millimeter wave radiation induces apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 human chondrosarcoma cells

The efficacy and safety of millimeter wave radiation has been proven for various types of malignant tumors. However, the mechanisms underlying effects of millimeter wave radiation on apoptosis are still unclear. The present study was undertaken to examine the effects of millimeter wave radiation on cell apoptosis and mitochondrial membrane potential, and to determine the molecular mechanism of millimeter wave radiation-induced apoptosis by investigating the expression of Bcl-2 family proteins (Bcl-2, Bax), caspase-9 and caspase-3 in SW1353 cells. We found that millimeter wave radiation suppressed the viability of SW1353 cells, demonstrating that millimeter wave radiation induced cell apoptosis and reduced cell viability in a time-dependent manner. Furthermore, we observed that treatment of cells with millimeter wave radiation significantly induced loss of mitochondrial membrane potential, upregulated proapoptotic Bax, caspase-9 and caspase-3, but did not significantly change levels of antiapoptotic Bcl-2. These data suggested that millimeter wave radiation may induce apoptosis via affecting the ratio of Bax/Bcl-2 in SW1353 cells.

Microwave photoresistance of a double quantum well at high filling factors

The effect of millimeter wave radiation on the electronic transport in a GaAs double quantum well at a temperature of 4.2 K in a magnetic field of up to 2 T has been studied. Resistance (conductance) oscillations have been shown to appear in the two-dimensional electronic system under investigation at high filling factors. The magnetic field positions of the oscillation maxima are determined by the condition ΔSAS/ħ = lωc, where ΔSAS = (E2 − E1) is the size quantization sublevel splitting in the quantum well, ωc is the cyclotron frequency, and l is a positive integer. It has been found that the microwave field substantially modifies the oscillations in the double quantum well, which results in alternating two-frequency oscillations of photoresistance with the inverse magnetic field.

Effect of millimeter wave radiation on the expression of proliferating cell nuclear antigen, CDK4 and P16 in rat hepatocellular carcinoma

OBJECTIVE: To study the effects of millimeter wave (MMW) radiation on rat hepatocellular carcinoma.METHODS: Forty male Wistar rats were randomly divided into four groups, and the liver region of the rats was directly radiated by MMW (35.8 GHz, 100 mW/cm2) for 20 min twice per week. Rats in groups 1 to 3 were fed with diethlnitrosamine (DEN). Group 1 was a tumor control group with sham radiation. Group 2 was given radiation for 10 weeks starting from week 5 and group 3 was radiated for 5 weeks starting from week 10. Group 4 was a normal control group radiated for 5 weeks and given distilled water. At week 14, all rats were sacrificed. A serological test for γ‐glutamyltransferase (γ‐GT) and immunohistochemical staining of proliferating cell nuclear antigen (PCNA), CDK4 and P16 in liver tissue were performed.RESULTS: The serum level of γ‐GT in group 1 (18.44 ± 4.88 U/L) was higher than that in group 2 (13.75 ± 2.41 U/L, P < 0.05), and the level of γ‐GT in group 3 (16.43 ± 2.12 U/L) was lower than that in group 1, but the difference was not significant. Based on histological examination of the livers, adenocarcinoma only developed in group 1. In the other DEN‐induced tumor groups, only eosinophilic and basophilic nodules were formed in the liver; no carcinoma cells were found. Expression of proliferating cell nuclear antigen (PCNA) and CDK4 staining in liver tissue in groups 2 and 3 were significantly lower than those in group 1, but the expression of P16 in the former was higher than that in the latter.CONCLUSIONS: Millimeter wave radiation partially inhibits cell proliferation and suppresses DEN‐induced hepatocellular carcinoma in rats.

Comment on: C. Koschnitzke, F. Kremer, L. Santo, P. Quick and A. Poglitsch, “A Non-Thermal Effect of Millimeter Wave Radiation on the Puffing of Giant Chromosomes” (Z. Naturforsch. 38c, 883-886, 1983).

Article Comment on: C. Koschnitzke, F. Kremer, L. Santo, P. Quick and A. Poglitsch, “A Non-Thermal Effect of Millimeter Wave Radiation on the Puffing of Giant Chromosomes” (Z. Naturforsch. 38c, 883-886, 1983). was published on December 1, 1984 in the journal Zeitschrift für Naturforschung C (volume 39, issue 11-12).

A non-thermal effect of millimeter wave radiation on the puffing of giant chromosomes.

A non-thermal influence of millimeter wave radiation (swept in frequency from 64.1 GHz to 69.1 GHz, sweeptime 6 s, and with stabilized frequencies of 67.200 +/- 0.001 GHz and 68.200 +/- 0.001 GHz, power density less than or equal to 6 mW/cm2) on the puffing of giant chromosomes of the midge Acricotopus lucidus (Diptera, Chironomidae) was found. The effect is manifested as a reduction in size of a specific puff that expresses genes for a secretory protein. The non-thermal nature of the effect was proved by experiments in which the sham-exposed sample was warmed up by 2.5 degrees C which is more than the eight-fold microwave induced temperature increase of less than or equal to 0.3 degrees C. Concerning the very low photon energy of mm-waves compared to the thermal energy kT, it seems likely that the coherence of the radiation is essential for the observed effect.