The influence of 1.2 microT, 60 Hz magnetic fields on melatonin- and tamoxifen-induced inhibition of MCF-7 cell growth.

We independently examined the findings of Harland and Liburdy, who reported that 1.2 microT(rms), 60 Hz magnetic fields could significantly reduce the inhibitory action of physiological levels of melatonin (10(-9) M) and of pharmacological levels of tamoxifen (10(-7) M) on the growth of MCF-7 human breast cancer cells in vitro. We used two testing protocols.

Experimental determination of hydrogen bandwidth for the ion parametric resonance model.

The ion parametric resonance (IPR) model predicts that distinct patterns of field-induced biological responses will occur at particular magnetic field combinations which establish ion resonances. An important characteristic of resonance is the bandwidth response of the system, in part because it determines the required tolerances of the test system. Initial development of the IPR model used literature data to estimate the bandwidth for any ion resonance to be -/+10% of its exact resonance.

Double blind test of magnetic field effects on neurite outgrowth.

Previous work reported that nerve growth factor-stimulated neurite outgrowth in PC-12 cells could be altered by exposure to parallel alternating current (AC) and direct current (DC) magnetic fields under a variety of exposure conditions, producing results that are consistent with the predictions of the ion parametric resonance (IPR) model. The credibility of these results, considered extraordinary by some scientists, could be strengthened if the cell response were found to persist under alternate assay conditions. We replaced part of our standard assay procedure with a double blind procedure.

Effect of perchloroethylene and its metabolites on intercellular communication in clone 9 rat liver cells.

Gap junction intercellular communication (IC) is thought to be important in chemical carcinogenesis as abnormalities in IC have been found in cancer cells. Perchloroethylene (PERC) is metabolized in rodent liver to dichloroacetic acid (DCA) and trichloroacetic acid (TCA), which are rodent liver carcinogens. Chloral hydrate (CH) and trichloroethanol (TCEth) are kidney metabolites.

Effect of ac and dc magnetic field orientation on nerve cells.

Recent tests of the influence of parallel ac and dc magnetic fields on neurite outgrowth in PC-12 cells showed good agreement with the predictions of an ion parametric resonance model. However, experimental results from earlier work involving both a perpendicular (160 mG) and a parallel (366 mG) dc magnetic field were not as consistent with the ion parametric resonance model predictions. Test results reported here show that the cell response to perpendicular ac and de magnetic fields is distinct and predictably different from that found for parallel ac and dc magnetic fields, and that the response to perpendicular fields is dominant in an intensity-dependent nonlinear manner.