EMF & EMX Scientific Information

Vol. 178, No. 3, 1991
Biochemical and Biophysical Research Communications
August 15, 1991
Pages 862-865

Effects of Coherence Time of the Applied Magnetic Field on Ornithine Decarboxylase Activity

T.A. Litovitz, D. Krause, and J.M. Mullins

Department of Physics and the
Department of Biology and Institute for Biomolecular Studies,
The Catholic University of America
Washington, D.C. 20064

Received June 6, 1991

Skepticism over the possibility of weak electromagnetic fields affecting cell function exists because endogenous thermal noise fields are larger than those reported to cause effects. Four- hour exposure to a 55- or 65-Hz field approximately doubles the specific activity of ornithine decarboxylase (ODC) in L929 cells. To test the idea that the cell discriminates against this thermal noise because it is incoherent, partial incoherence was introduced into the applied field by shifting the frequency between 55- to 65-Hz at intervals of t _00h - dt where t_00h is a predetermined time interval and dt << t_00h varies randomly from one frequency shift to the next. To obtain the full ODC enhancement, coherence of the impressed signal must be maintained for a minimum of about 10s. For t_00h = 5.0s a partial enhancement is elicited, and at 1.0s there is no response. Unfortunately coherence times of this duration are too short to solve the thermal noise puzzle. 1991 Academic Press, Inc.

0006-291X/91
Copyright „ 1991 by Academic Press, Inc.
All rights of reproduction in any form reserved.

Martin Blank, Ed., Electricity and Magnetism in Biology and Medicine
Copyright „ 1993 by San Francisco Press, Inc., Box 426800, San Francisco, CA 94142-6800, USA

Superposition of a Temporally Incoherent Magnetic Field Suppresses the Change in Ornithine Decarboxylase Activity in Developing Check Embryos Induced by a 60Hz Sinusoidal Fields

J.M. Farrell, M. Barber, P. Doinov, D. Krause, and T.A. Litovitz

Catholic University of America, Washington

Developing chick embryos were exposed to 60 Hz sinusoidal magnetic fields under the environmental conditions specified in the "Henhouse" experiment. The activity of ornithine decarboxylase (ODC) was compared with that in sham-exposed embryos for an incubation time of 15 h. A ratio of 1.74 +/- 0.36 (N = 270) was obtained. In other experiments, ODC activity was analyzed in embryos exposed to 60 Hz sinusoidal fields on which a spatially coherent, but temporally incoherent "noise" field was superimposed. This randomly generated field contained frequencies ranging from 30 to 90 Hz and an rms value comparable to the sinusoidal field’s peak amplitude. Embryos so exposed had an ODC activity that was statistically indistinguishable from the controls. Thus, embryo biochemistry is shown to be modified by the imposition of a sinusoidal magnetic field. However, this modification is shown to be blocked by the superposition of temporally incoherent EM fields of comparable strengths.

*Correspondence to J.M. Farrell (Physics), Catholic University of America, Washington, D.C. 20064

Martin Blank, Ed., Electricity and Magnetism in Biology and Medicine
Copyright „ 1993 by San Francisco Press, Inc., Box 426800, San Francisco, CA 94142-6800, USA

Simultaneous Application of a Spatially Coherent Noise Field Blocks Response of Cell Cultures to a 60Hz Electromagnetic Field

J.M.Mullins, D. Krause, and T.A. Litovitz

Catholic University of America, Washington, D.C.

L929 murine fibroblasts display a doubling of ornithine decarboxylase activity following 4h exposure to a 60Hz magnetic field of 10 mT. Simultaneous application of a spatially coherent noise field of comparable amplitude eliminated enhancement of ornithine decarboxylase activity by the stimulating field. Lowering of the amplitude of the applied noise field restored field-induced enhancement of enzyme activity. These results are discussed in terms of the thermal-noise limit for weak-field detection.

*Correspondence to J.M. Mullins (Biology), Catholic University of America, Washington, D.C. 20064

Bioelectromagnetics 15:399-409 (1994)

Temporally Incoherent Magnetic Fields Mitigate the Response of Biological Systems to Temporally Coherent Magnetic Fields

T.A. Litovitz, D. Krause, C.J. Montrose, and J.M. Mullins

Vitreous State Laboratory (T.A.L., C.J.M.) and Department of Biology (D.K., J.M.M.),
The Catholic University of America, Washington, District of Columbia

We have previously demonstrated that a weak, extremely–low- frequency magnetic field must be coherent for some minimum length of time (ª 10 s) in order to affect the specific activity of ornithine decarboxylase (ODC) in L929 mouse cells. In this study we explore whether or not the superposition of an incoherent (noise) magnetic field can block the bioeffect of a coherent 60 Hz magnetic field, since the sum of the two fields is incoherent. An experimental test of this idea was conducted using as a biological marker the twofold enhancement of ODC activity found in L929 murine cells after exposure to a 60Hz, 10mT rms magnetic field. We superimposed an incoherent magnetic noise field, containing frequencies from 30 to 90 Hz, whose rms amplitude was comparable to that of the 60 Hz field. Under these conditions the ODC activity observed after exposure was equal to control levels. It is concluded that the superposition of incoherent magnetic fields can block the enhancement of ODC activity by a coherent magnetic field if the strength of the incoherent field is equal to or greater than that of the coherent field. When the superimposed, incoherent field was reduced in strength, the enhancement of ODC activity by the coherent field increased. Full ODC enhancement was obtained when the rms value the applied EM noise was less than one-tenth that of the coherent field. These results are discussed in relation to the question of cellular detection of weak EM fields in the presence of endogenous thermal noise fields. 1994 Wiley-Liss, Inc.

Key words: noise, coherence, incoherence, signal to noise, ornithine decarboxylase

Address reprint requests to T.A. Litovitz, Vitreous State Laboratory, Catholic University of America, Washington, DC 20064

Vol.36, No.1, May 1995
Biochemistry and Molecular Biology International
Pages 87-94

Effectiveness of Noise in Blocking Electromagnetic Effects on Enzyme Activity in the Chick Embryo

A. H. Martin and G. C. Moses

Department of Anatomy, The University of Western Ontario
and Department of Biochemistry, Victoria Hospital and
The University of Western Ontario, London, Ontario, Canada

Received February 19, 1995
Received after revision, March 17, 1995

Summary
We have previously demonstrated that exposure of the chick embryo to a 60Hz, 4 mT split sine wave for the first 72 hours of development causes a significant reduction in the activity of the ectoenzyme 5’-nucleotidase. This reduced activity persisted, throughout the embryonic period, despite further incubation in a field free environment. We also showed that the reduction in 5’NT activity can be localized in the developing brain to the Cerebellum. The present study reveals that superimposition of an electromagnetic noise, of similar amplitude and frequency, can mitigate the effect of the field on 5’NT activity.

Key Words: chick embryo; electromagnetic fields; 5’-Nucleotidase and electromagnetic noise.

Bioelectrochemistry and Bioenergetics 36 (1995) 33-37

Electric and magnetic noise blocks the 60 Hz magnetic field enhancement of steady state c-myc transcript levels in human leukemia cells

Hana Lin, Reba Goodman

Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, NY 20032, USA

Received 23 May 1994

Abstract

We have previously demonstrated that exposure of human cultured cells to 60 Hz sinusoidal magnetic fields causes an increase in steady state transcript levels for the proto-oncogene c-myc. A study by Litovitz et al. (T.A. Litovitz, D. Krause and J.M. Mullins, Biochem. Biophys. Res. Commun., 178(1991) 862) suggests that the induction of bioeffects from exposure to 60 Hz fields requires that the exposure field be coherent for some minimum length of time (approximately 10s). A related study demonstrated that these effects can be blocked by superposition of temporally incoherent magnetic noise fields. In this paper we investigate whether or not the superposition of a magnetic noise field can block the bioeffect of a coherent 60 Hz magnetic field on the transcript levels of the proto-oncogene c-myc in HL60 cells. Experiments were performed using band-limited magnetic noise fields (30-90 Hz, 6.7 mT rms). The results show that exposure to the 60 Hz field alone produces approximately a 40% enhancement of the c-myc transcript. Superposition of the noise field on the 60 Hz field inhibited the enhancement the c-myc transcript to the extent that no statistically significant was observed. This study provides additional proof of the coherence time requirement, and of the validity of the noise superposition method to block electric and magnetic field induced bioeffects.

Keywords: Transcript; c-myc; Electric and magnetic field; Noise

*Corresponding author. Columbia University Health Sciences, Department of Pathology, 630 W. 168 Street, New York, NY 10032, USA (Tel. 212-305-3643).

Bioelectromagnetics 18:132-141 (1997)

Role of Modulation on the Effect of Microwaves on Ornithine Decarboxylase Activity in L929 Cells

L. Miguel Penafiel, Theodore Litovitz, David Krause, Abiy Desta, and J. Michael Mullins

Department of Biology, The Catholic University of America, Washington, DC
Vitreous State Laboratory, The Catholic University of America, Washington, DC

The effect of 835 MHz microwaves on the activity of ornithine decarboxylase (ODC) in L929 murine cells was investigated at an SAR of ~2.5 W/kg. The results depend upon the type of modulation employed. AM frequencies of 16 Hz produced a transient increase on ODC activity that reached a peak at 8 h of exposure and returned to control levels after 24 h of exposure. In this case, ODC was increased by a maximum of 90% relative to control levels. A 40% increase in ODC activity was also observed after 8 h of exposure with a typical signal from a TDMA digital cellular telephone operating in the middle of its transmission frequency range (~840 MHz). This signal was burst modulated at 50 Hz, with approximately 30% duty cycle. By contrast, 8 h exposure with 835 MHz microwaves, frequency modulated with a 60 Hz sinusoid, yielded no significant enhancement in ODC activity exposure times ranging between 2 and 24 h. Similarly, exposure with a typical signal from an AMPS analog cellular telephone, which uses a form of frequency modulation, produced no significant enhancement in ODC activity. Exposure with 835 MHz continuous wave microwaves produced no effects for exposure times between 2 and 24 h, except for a small but statistically significant enhancement in ODC activity after 6 h of exposure. Comparison of these results suggests that effects are much more robust when the modulation causes low-frequency periodic changes in the amplitude of the microwave carrier. Bioelectromagnetics 18:132-141, 1997. „ 1997 Wiley-Liss, Inc.

Bioelectromagnetics 18:422-430 (1997)

Bioeffects Induced by Exposure to Microwaves Are Mitigated by Superposition of ELF Noise

T.A. Litovitz, L.M. Penafield, J.M. Farrel, D. Krause, R.Meister, and J.M. Mullins

Vitreous State Laboratory, The Catholic University of America, Washington, DC
Department of Biology, The Catholic University of America, Washington, DC
Department of Electrical Engineering, The Catholic University of America, Washington, DC

We have previously demonstrated that microwave fields, amplitude modulated (AM) by an extremely low-frequency sine wave, can induce a nearly twofold enhancement in the activity of ornithine decarboxylase (ODC) in L929 cells at SAR levels of he order of 2.5 W/kg. Similar, although less pronounced, effects were also observed from exposure to a typical digital cellular phone test signal of the same power level, burst modulated at 50 Hz. We have also shown that IDC enhancement in L929 cells produced by exposure to ELF fields can be inhibited by superposition of ELF noise. In the present study, we explore the possibility that similar inhibition techniques can be used to suppress the microwave response. We concurrently exposed L929 cells to 60Hz AM microwave fields or a 50 Hz burst-modulated DAMPS (Digital Advanced Mobile Phone System) digital cellular phone field at levels known to produce ODC enhancement, together with band-limited 30-100 Hz ELF noise with root mean square amplitude of up to 10 mT. All exposures were carried out for 8 h, which was previously found to yield the peak microwave response. In both cases, the ODC enhancement was found to decrease exponentially as a function of the noise root mean square amplitude. With 60 Hz AM microwaves, complete inhibition was obtained with noise levels at or above 2 mT. With the DAMPS digital cellular phone signal, complete inhibition occurred with noise levels at or above 5 mT. These results suggest a possible practical means to inhibit biological effects from exposure to both ELF and microwave fields. Bioelectromagnetics 18:422-430 (1997)........1997 Wiley-Liss, Inc.

Key words: cellular phones; EMFs; biological effects; amplitude modulation

Bioelectrochemistry and Bioenergetics 40 (1996) 193-196

The minimizing effect of electromagnetic noise on the changes in cell proliferation caused by ELF magnetic fields

P. Raskmark, S. Kwee

Institute of Communication Technology, Aalborg University, DK-9220 Aalborg Denmark
Institute of Medical Biochemistry, University of Aarhus, Building DK-8000 Aarhus C, Denmark

Received 26 January 1996; accepted 15 February 1996

Abstract

A significant increase in cell growth was registered in human epithelial amnion (AMA) cells, when exposed to a sinusoidal 50 Hz, 50 µT electromagnetic fields (S. Kwee and P. Raskmark, Bioelectrochem. Bioenerg., 36 (1995) 109). To study the effects of incoherent magnetic fields on the biological changes caused by the electromagnetic fields, varying levels of noise were superimposed on the above-mentioned field. No inhibition of the coherent magnetic field effects were seen at low noise magnetic field destinies. However, when the noise reached a level of 70-80% of the magnetic field, a significant inhibition of the increased cell proliferation was registered. The imposed inhibition remained constant up to a noise level equal to the magnetic field. No significant change in proliferation rate was seen when the cell culture was exposed to a noise field only.

Keywords: Electromagnetic noise; Cell proliferation; AMA cells; Microtiter plate cultivation; Response inhibition