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  • Articles  (83)
  • Life and Medical Sciences  (83)
  • EARTH RESOURCES AND REMOTE SENSING
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  • 1995-1999  (83)
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  • 1997  (83)
  • Physics  (83)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of a low-voltage static electric field on energy metabolism in astrocytes (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 77-80 
    Details
    ISSN: 0197-8462
    Keywords: astrocytes ; astrocytoma ; electromagnetic field ; energy metabolism ; glycolysis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Mouse astrocytes (glial cells) in primary cultures were exposed to a low-voltage static DC electric field with no current flow and thus with no generation of magnetic fields. The electric field altered the rate of glycolysis, measured by 2-deoxyglucose accumulation. The magnitude and direction of this effect depended on the polarization of the field and the applied voltage. The maximum effect was an increase of ∼30%, which occurred with field across the cells at an intensity that can be calculated to be 0.3 mV/cm or less. Reversal of the polarization converted the stimulation to a small but statistically significant inhibition. Bioelectromagnetics 18:77-80, 1997. © 1997 Wiley-Liss, Inc.
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  • 2
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    Comparison of coupling of humans to electric and magnetic fields with frequencies between 100 Hz and 100 kHz (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 67-76 
    Details
    ISSN: 0197-8462
    Keywords: dosimetry ; transients ; electric fields ; magnetic fields, nonionizing ; ellipsoidal models ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Recent laboratory and epidemiological results have stimulated interest in the hypothesis that human beings may exhibit biological responses to magnetic and/or electric field transients with frequencies in the range between 100 Hz and 100 kHz. Much can be learned about the response of a system to a transient stimulation by understanding its response to sinusoidal disturbances over the entire frequency range of interest. Thus, the main effort of this paper was to compare the strengths of the electric fields induced in homogeneous ellipsoidal models by uniform 100 Hz through 100 kHz electric and magnetic fields. Over this frequency range, external electric fields of about 25-2000 V/m (depending primarily on the orientation of the body relative to the field) are required to induce electric fields inside models of adults and children that are similar in strength to those induced by an external 1 μT magnetic field. Additional analysis indicates that electric fields induced by uniform external electric and magnetic fields and by the nonuniform electric and magnetic fields produced by idealized point sources will not differ by more than a factor of two until the sources are brought close to the body. Published data on electric and magnetic field transients in residential environments indicate that, for most field orientations, the magnetic component will induce stronger electric fields inside adults and children than the electric component. This conclusion is also true for the currents induced in humans by typical levels of 60 Hz electric and magnetic fields in U.S. residences. Bioelectromagnetics 18:67-76, 1997. © 1997 Wiley-Liss, Inc.
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  • 3
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    Cell-cycle kinetics of friend erythroleukemia cells in a magnetically shielded room and in a low-frequency/low-intensity magnetic field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 58-66 
    Details
    ISSN: 0197-8462
    Keywords: culture growth cycle ; cellular volume ; survival ; differentiation ; adaptation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This work was undertaken to compare the behavior of Friend erythroleukemia cells in a solenoid, where the magnetic field was 70 μT at 50 Hz (plus 45 μT DC of Earth) with that of the same cells in a magnetically shielded room, where the magnetic field was attenuated to 20 nT DC and 2.5 pT AC. The control laboratory magnetic field corresponded to 45 μT DC and a stray 50 Hz field below 0.2 μT. The culture growth cycle of cells maintained inside the solenoid was slightly accelerated compared with that of cells maintained outside the solenoid (P 〈 .05). This stimulation probably depended on sensitivity of cell cycle to a magnetic field, because, inside the solenoid, the percentage of G1 cells slightly increased during the culture growth cycle, whereas that of S cells slightly decreased. Acceleration of growth was detected soon after exposure of the cultures to the solenoid field, and growth did not change further if the action of this field continued for a long time, accounting for adaptation. The solenoid field also caused a small increase of cell survival without influencing cell volume. By contrast, the culture growth cycle of cells maintained inside the magnetically shielded room was slightly decelerated compared with that of cells maintained outside the room (P 〈 .05). The essential absence of any field inside the magnetically shielded room also caused a small increase of cell volume, whereas, during the culture growth cycle, the percentage of G1 cells decreased, and that of S cells increased. The majority of these events did not change in cells induced to differentiate hemoglobin through dimethylsulfoxide. Bioelectromagnetics 18:58-66, 1997. © 1997 Wiley-Liss, Inc.
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  • 4
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    Electric-field ion cyclotron resonance (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 85-87 
    Details
    ISSN: 0197-8462
    Keywords: geomagnetic field ; endogenous electric fields ; ELF magnetic fields ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We consider the possibility that DC magnetic fields can interact in a resonant manner with endogenous AC electric fields in biological systems. Intrinsic electric-field ion cyclotron resonance (ICR) interactions would be more physically credible than models based on external AC magnetic fields and might be expected as an evolutionary response to the long-term constancy of the geomagnetic field. Bioelectromagnetics 17:85-87, 1997. © 1997 Wiley-Liss, Inc.
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  • 5
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    Whittington CJ, Podd JV, Rapley BR (1996): Acute effects of 50 Hz magnetic field exposure on human visual task and cardiovascular performance. Biolectromagnetics 17:131-137 (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 88-88 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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  • 6
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    Wire codes, magnetic fields, and childhood cancer (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 99-110 
    Details
    ISSN: 0197-8462
    Keywords: epidemiology ; misclassification ; residential exposure ; review ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Childhood cancer has been modestly associated with wire codes, an exposure surrogate for power frequency magnetic fields, but less consistently with measured fields. We analyzed data on the population distribution of wire codes and their relationship with several measured magnetic field metrics. In a given geographic area, there is a marked trend for decreased prevalence from low to high wire code categories, but there are differences between areas. For average measured fields, there is a positive relationship between the mean of the distributions and wire codes but a large overlap among the categories. Better discrimination is obtained for the extremes of the measurement values when comparing the highest and the lowest wire code categories. Instability of measurements, intermittent fields, or other exposure conditions do not appear to provide a viable explanation for the difference between wire codes and magnetic fields with respect to the strength and consistency of their respective association with childhood cancer. Bioelectromagnetics 18:99-110, 1997. © 1997 Wiley-Liss, Inc.
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  • 7
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    Millimeter waves thermally alter the firing rate of the Lymnaea pacemaker neuron (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 89-98 
    Details
    ISSN: 0197-8462
    Keywords: millimeter waves ; mollusc neuron ; pacemaker activity ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of millimeter waves (mm-waves, 75 GHz) and temperature elevation on the firing rate of the BP-4 pacemaker neuron of the pond snail Lymnaea stagnalis were studied by using microelectrode techniques. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates (SARs), measured in physiological solution at the radiator outlet, ranged from 600 to 4200 W/kg, causing temperature rises from 0.3 to 2.2 °C, respectively. Irradiation at an SAR of 4200 W/kg caused a biphasic change in the firing rate, i.e., a transient decrease in the firing rate (69 ± 22% below control) followed by a gradual increase to a new level that was 68 ± 21% above control. The biphasic changes in the firing rate were reproduced by heating under the condition that the magnitude (2 °C) and the rate of temperature rise (0.96 °C/s) were equal to those produced by the irradiation (for an SAR of 4030 W/kg). The addition of 0.05 mM of ouabain caused the disappearance of transient responses of the neuron to the irradiation. It was shown that the rate of temperature rise played an important role in the development of a transient neuronal response. The threshold stimulus for a transient response of the BP-4 neuron found in warming experiments was a temperature rise of 0.0025 °C/s. Bioelectromagnetics 18:89-98, 1997. © 1997 Wiley-Liss, Inc.
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  • 8
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    Do electromagnetic fields interact directly with DNA? (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 111-115 
    Details
    ISSN: 0197-8462
    Keywords: signal transduction ; transcription ; biosynthesis ; Na,K-ATPase ; mobile charges ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The mechanisms whereby electromagnetic (EM) fields stimulate changes in biosynthesis in cells are not known. It has generally been assumed that EM fields first interact with cell membranes, but this pathway may not be the only one. Interactions with membranes are well documented, but recent studies of EM signal transduction in the membrane Na,K-ATPase are best explained by direct interaction of electric and magnetic fields with mobile charges within the enzyme. Interaction with moving charges may be a mechanism that is operative in other biopolymers. Recent studies on DNA have shown that large electron flows are possible within the stacked base pairs of the double helix. Therefore, gene activation by magnetic fields could be due to direct interaction with moving electrons within DNA. Electric fields as well as magnetic fields stimulate transcription, and both fields could interact with DNA directly. The mechanism of EM field-stimulated transcription may be related to the process in striated muscles, where endogenous electrical activity induces the synthesis of new proteins. Bioelectromagnetics 18:111-115, 1997. © 1997 Wiley-Liss, Inc.
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  • 9
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    Effects function simulation of residential appliance field exposures (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 116-124 
    Details
    ISSN: 0197-8462
    Keywords: magnetic fields ; appliances ; exposure ; effects functions ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This paper demonstrates the application of effects function analysis to residential magnetic field exposure, focusing on appliance sources and mitigation choices. Residential field exposure time series were synthesized by using a sample of background household field measurements, a model of average daily appliance use, and a small sample of EMDEX data of field exposure from 12 household appliances. Four alternative effects functions (average field strength with or without a threshold, field strength window, sudden field changes) were simulated by using the synthesized time series data for different exposure situations, such as high and low levels of appliance use, simple avoidance, and use of a set of hypothetical “low field” appliances (50% lower fields). In particular, field exposure from the use of bedside clocks and electric blankets was examined. Results demonstrate that the choice of effects function is critical for the ranks of field sources and exposure reduction choices. For the effects function of average field strength with or without a threshold, exposure from background fields dominated exposure from all appliances except for bedside clocks and electric blankets. In the case of the field strength window effects function, the dominant field sources changed with the width of the window. For the effects function based on rapid field changes, appliance use was the major source of exposure. Because of the small sample size of our data set and other simplifications, specific results should be viewed as illustrative. Bioelectromagnetics 18:116-124, 1997. © 1997 Wiley-Liss, Inc.
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  • 10
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    In vitro effects of 50 Hz magnetic fields on oxidatively damaged rabbit red blood cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 125-131 
    Details
    ISSN: 0197-8462
    Keywords: hexokinase ; free radicals ; oxidative damage ; magnetic fields ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The aim of this study was to investigate the effects of 50 Hz magnetic fields (0.2-0.5 mT) on rabbit red blood cells (RBCs) that were exposed simultaneously to the action of an oxygen radical-generating system, Fe(II)/ascorbate. Previous data obtained in our laboratory showed that the exposure of rabbit erythrocytes or reticulocytes to Fe(II)/ascorbate induces hexokinase inactivation, whereas the other glycolytic enzymes do not show any decay. We also observed depletion of reduced glutathione (GSH) content with a concomitant intracellular and extracellular increase in oxidized glutathione (GSSG) and a decrease in energy charge. In this work we investigated whether 50 Hz magnetic fields could influence the intracellular impairments that occur when erythrocytes or reticulocytes are exposed to this oxidant system, namely, inactivation of hexokinase activity, GSH depletion, a change in energy charge, and hemoglobin oxidation. The results obtained indicate that a 0.5 mT magnetic field had no effect on intact RBCs, whereas it increased the damage in an oxidatively stressed erythrocyte system. In fact, exposure of intact erythrocytes incubated with Fe(II)/ascorbate to a 0.5 mT magnetic field induced a significant further decay in hexokinase activity (about 20%) as well as a twofold increase in methemoglobin production compared with RBCs that were exposed to the oxidant system alone. Although further studies will be needed to determine the physiological implications of these data, the results reported in this study demonstrate that the effects of the magnetic fields investigated are able to potentiate the cellular damage induced in vitro by oxidizing agents. Bioelectromagnetics 18:125-131, 1997. © 1997 Wiley-Liss, Inc.
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  • 11
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    Role of modulation on the effect of microwaves on ornithine decarboxylase activity in L929 cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 132-141 
    Details
    ISSN: 0197-8462
    Keywords: cellular phones ; EMFs ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: 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 depended upon the type of modulation employed. AM frequencies of 16 Hz and 60 Hz produced a transient increase in 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 amplitude modulated with speech produced no significant change in ODC activity. Further investigations, with 8 h of exposure to AM microwaves, as a function of modulation frequency, revealed that the response is frequency dependent, decreasing sharply at 6 Hz and 600 Hz. Exposure with 835 MHz microwaves, frequency modulated with a 60 Hz sinusoid, yielded no significant enhancement in ODC activity for 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.
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  • 12
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    Extremely high frequency electromagnetic fields at low power density do not affect the division of exponential phase Saccharomyces cerevisiae cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 142-155 
    Details
    ISSN: 0197-8462
    Keywords: cell cycle ; electromagnetic field ; nonthermal effects ; yeast ; extremely high frequency ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Exponentially growing cells of the yeast Saccharomyces cerevisiae were exposed to electromagnetic fields in the frequency range from 41.682 GHz to 41.710 GHz in 2 MHz increments at low power densities (0.5 μW/cm2 and 50 μW/cm2) to observe possible nonthermal effects on the division of this microorganism. The electronic setup was carefully designed and tested to allow precise determination and stability of the electromagnetic field parameters as well as to minimize possible effects of external sources. Two identical test chambers were constructed in one exposure system to perform concurrent control and test experiments at every frequency step under well-controlled exposure conditions. Division of cells was assessed via time-lapse photography. Control experiments showed that the cells were dividing at submaximal rates, ensuring the possibility of observing either an increase or a decrease of the division rate. The data from several independent series of exposure experiments and from control experiments show no consistently significant differences between exposed and unexposed cells. This is in contrast to previous studies claiming nonthermal effects of electromagnetic fields in this frequency range on the division of S. cerevisiae cells. Possible reasons for this difference are discussed. Bioelectromagnetics 18:142-155, 1997. © 1997 Wiley-Liss, Inc.
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  • 13
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    Acute exposure to a 60 Hz magnetic field increases DNA strand breaks in rat brain cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 156-165 
    Details
    ISSN: 0197-8462
    Keywords: 60 Hz magnetic fields ; DNA single-strand and double-strand breaks ; brain cells ; microgel electrophoresis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Acute (2 h) exposure of rats to a 60 Hz magnetic field (flux densities 0.1, 0.25, and 0.5 mT) caused a dose-dependent increase in DNA strand breaks in brain cells of the animals (assayed by a microgel electrophoresis method at 4 h postexposure). An increase in single-strand DNA breaks was observed after exposure to magnetic fields of 0.1, 0.25, and 0.5 mT, whereas an increase in double-strand DNA breaks was observed at 0.25 and 0.5 mT. Because DNA strand breaks may affect cellular functions, lead to carcinogenesis and cell death, and be related to onset of neurodegenerative diseases, our data may have important implications for the possible health effects of exposure to 60 Hz magnetic fields. Bioelectromagnetics 18:156-165, 1997. © 1997 Wiley-Liss, Inc.
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  • 14
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    Measurement of low frequency magnetic fields from digital cellular telephones (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 184-186 
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    ISSN: 0197-8462
    Keywords: power supply ; pulsed battery current ; GSM ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Digital cellular telephones using the GSM (Global System for Mobile Communication) transmit information in bursts of microwaves. This pulsed transmitting mode causes the battery current and currents in the electronics of the apparatus to be pulsed. These pulsed currents produce corresponding pulsed magnetic fields near the phones. A study to determine the magnitude of these fields involved two models of digital telephones. The highest value of the magnetic flux density was 1.8 μT (rms). Bioelectromagnetics 18:184-186, 1997. © 1997 Wiley-Liss, Inc.
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  • 15
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    Human melatonin during continuous magnetic field exposure (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 166-171 
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    ISSN: 0197-8462
    Keywords: extremely low frequency ; electromagnetic field ; human ; neuroendocrine ; cancer ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This report describes the third in a series of double-blind, laboratory-based studies that were aimed at determining the effects of nocturnal exposure to power frequency magnetic fields on blood levels of melatonin in human volunteers. Our two earlier studies evaluated effects on melatonin of intermittent exposure to 60 Hz circularly polarized magnetic fields at 10 and 200 mG. No overall effects on melatonin levels were found. In the present study, men were exposed continuously rather than intermittently through the night to the same 200 mG magnetic field condition that was used previously; again, no overall effects on melatonin levels were found. We conclude that the intermittent and continuous exposure conditions used in our laboratory to date are not effective in altering nocturnal blood levels of melatonin in human volunteers. Bioelectromagnetics 18:166-171, 1997. © 1997 Wiley-Liss, Inc.
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  • 16
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    Action of a 50 Hz magnetic field on proliferation of cells in culture (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 177-183 
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    ISSN: 0197-8462
    Keywords: cell growth ; cell cycle ; low-frequency electromagnetic field ; induced electric field ; chronobiological effects ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Proliferation of SV40-3T3 mouse fibroblasts and human HL-60 promyelocytes was studied after treatment with a sinusoidal 2 mTrms 50 Hz magnetic field. A single exposure of 60 minutes caused quasicyclic changes in the cell number of SV40-3T3 cultures as function of time after treatment, which was interpreted to be due to the induction of chronobiological mechanisms by the field. Moreover, small variations in cell cycle distribution were measured during postexposure incubation for both cell lines. To discriminate between the effect of the magnetic vector and the induced electric field, HL-60 cell exposure was also performed on organ culture dishes. These dishes consist of two coaxially centered, isolated compartments in which different electric field levels are induced in the medium during treatment. Cell growth was affected in the outer compartment only where the induced electric field ranged from 8 to 12 mVpeak/meter at 2 mT, but it was not affected in the inner compartment (field range 0-4 mVpeak/meter). This suggests that the effects on cell growth are due to the induced electric field and are expressed only above a threshold of between 4 and 8 mVpeak/meter. Bioelectromagnetics 18:177-183, 1997. © 1997 Wiley-Liss, Inc.
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  • 17
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    No short-term effects of digital mobile radio telephone on the awake human electroencephalogram (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 172-176 
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    ISSN: 0197-8462
    Keywords: electroencephalogram ; electromagnetic field ; digital mobile phone ; radio telephone ; GSM system ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8-13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, we investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C3 and C4 and comparing the effects of an active (0.05 mW/cm2) and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 μs, we could not detect any difference in the awake EEGs in terms of spectral power density measures. Bioelectromagnetics 18:172-176, 1997. © 1997 Wiley-Liss, Inc.
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  • 18
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    Molecular wring resonances in chain molecules (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 187-189 
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    ISSN: 0197-8462
    Keywords: DNA ; hydrolysis ; linking ; microwaves ; protein ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: It is shown that the eigenfrequency of collective twist excitations in chain molecules can be in the megahertz and gigahertz range. Accordingly, resonance states can be obtained at specific frequencies, and phenomena that involve structural properties can take place. Chain molecules can alter their conformation and their ability to function, and a breaking of the chain can result. It is suggested that this phenomenon forms the basis for effects caused by the interaction of microwaves and biomolecules, e.g., microwave assisted hydrolysis of chain molecules. Bioelectromagnetics 18:187-189, 1997. © 1997 Wiley-Liss, Inc.
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  • 19
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    Urinary 6-sulphatoxymelatonin excretion is increased in rats after 24 hours of exposure to vertical 50 Hz, 100 μT magnetic field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 190-192 
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    ISSN: 0197-8462
    Keywords: melatonin ; pineal gland ; 6-sulphatoxymelatonin ; aMT6s ; ELF ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effect of exposure to a 50 Hz, vertical magnetic field on the excretion of urinary 6-sulphatoxymelatonin (aMT6s) of rats was studied in a self-controlled experiment. Ten male Wistar rats were kept under 9:15 h light:dark conditions in metabolic cages. The rats were exposed to 1.0 or 100 μT flux density for 24 h. The excretion of aMT6s, which is the primary metabolite of melatonin in the urine, did not show a statistically significant decrease, as measured by 125I radioimmunoassay, during or after magnetic field exposure of rats to either flux density. At 100 μT flux density, the increase of aMT6s excretion on the day after exposure was statistically significant (P 〈 .02), compared with the value under exposure, but was not significant compared with the baseline values before exposure. Bioelectromagnetics 18:190-192, 1997. © 1997 Wiley-Liss, Inc.
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  • 20
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    Mechanical and electrical interactions in bone remodeling (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 193-202 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic fields ; mechanical strain ; adaptation ; bone cells ; Wolff's law ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The natural remodeling and adaptation of skeletal tissues in response to mechanical loading is a classic example of physical regulation in biology. It is largely because it involves forces that do not seem to fit into the familiar schemes of biochemical controls that bone adaptation mechanisms have intrigued us for at least a century. The effect of electromagnetic fields on organisms is another example of this, and the two have become linked in an attempt to explain bone remodeling (“Yasuda's hypothesis”). This paper re-examines the roles of endogenous and exogenous electromagnetic fields in the response of bone to mechanical forces. A series of experiments is reviewed in which mechanical and electrical stimuli were applied to implants in the medullary canal of rabbit long bones. The results suggest that endogenously generated electrical currents are not required to initiate mechanically stimulated bone formation, but that direct mechanical effects on bone cells is the more likely scenario. Based on this and other evidence from the literature, it is suggested that when exogenous electromagnetic stimuli are applied, bone cells respond by modulating the activity of more primary activators such as hormones, growth factors, cytokines, and mechanical forces. Bioelectromagnetics 18:193-202, 1997. © 1997 Wiley-Liss, Inc.
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    Effects of a homogeneous magnetic field on erythrocyte sedimentation and aggregation (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 215-222 
    Details
    ISSN: 0197-8462
    Keywords: diamagnetic erythrocyte ; Westergren method ; cell orientation ; blood rheology ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Effects of a homogeneous static magnetic field on erythrocyte sedimentation rate (ESR) have been assessed by using the standard Westergren method. A magnetic field of 6.3 T in the vertical direction only slightly enhanced ESR in saline solution, which was consistent with an effect on cell orientation. On the other hand, the magnetic field greatly enhanced ESR in plasma. It took a long time (about 20 min) for an ESR change to occur in plasma in response to the magnetic field. The effects in plasma were too large to originate only from cell orientation and were clearly distinct from a magnetic field-induced Boycott effect under an inhomogeneous magnetic field. A morphological examination and the nonlinear time course of the sedimentation in plasma indicated that the magnetic field increased cell aggregation and thereby enhanced ESR in plasma. Bioelectromagnetics 18:215-222, 1997. © 1997 Wiley-Liss, Inc.
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    Serum plays a critical role in modulating [Ca2+]c of primary culture bone cells exposed to weak ion-resonance magnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 203-214 
    Details
    ISSN: 0197-8462
    Keywords: tissue culture ; ion resonance ; IR magnetic field ; resonance frequency ; fura-2 ; single cell study ; serum ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Primary-culture bone cells were exposed to ion-resonance (IR) magnetic fields tuned to Ca2+. Cytosolic calcium concentration, [Ca2+]c, was measured by using fura-2 during field exposure. The fields investigated were 20 μT static + 40 μT p-p at either 15.3 or 76.6 Hz, and 0.13 mT static + either 0.5 or 1.0 mT p-p at 100 Hz. Other parameters included field orientation, culture age (2 or 5 days after plating), and the presence of serum (0 or 2%) during exposure. Total experiment time was 29.5 min: The field was applied after 2 min, and bradykinin was added as an agonist control after 22 min. The data were quantified on a single-cell basis during the 2-22 min exposure period in terms of the magnitude of the largest occurring [Ca2+]c spike normalized to local baseline. Field-exposed and control groups were characterized in terms of the percent of cells exhibiting spike magnitudes above thresholds of 100 or 66% over baseline and were compared by using Fisher's exact test. Without serum, there was little evidence that IR magnetic fields altered [Ca2+]c. However, in the presence of 2% serum, 3 of the 16 experiments exhibited significant effects at the 100% threshold. Reducing this threshold to 66% resulted in five experiments exhibiting significant effects. Most strikingly, in all of these cases, the field acted to enhance [Ca2+]c activity as opposed to suppressing [Ca2+]c activity. These findings suggest a role for serum or for constituents within serum in mediating the effects of IR magnetic fields on cells and may provide a resolution pathway to the dilemma imposed by theoretical arguments regarding the possibility of such phenomena. Possible roles of serum and future studies are discussed. Bioelectromagnetics 18:203-214, 1997. © 1997 Wiley-Liss, Inc.
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    Exposure of nerve growth factor-treated PC12 rat pheochromocytoma cells to a modulated radiofrequency field at 836.55 MHz: Effects on c-jun and c-fos expression (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 223-229 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic fields ; gene expression ; transcription factors ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Rat PC12 pheochromocytoma cells have been treated with nerve growth factor and then exposed to athermal levels of a packet-modulated radiofrequency field at 836.55 MHz. This signal was produced by a prototype time-domain multiple-access (TDMA) transmitter that conforms to the North American digital cellular telephone standard. Three slot average power densities were used: 0.09, 0.9, and 9 mW/cm2. Exposures were for 20, 40, and 60 min and included an intermittent exposure regimen (20 min on/20 min off), resulting in total incubation times of 20, 60, and 100 min, respectively. Concurrent controls were sham exposed. After extracting total cellular RNA, Northern blot analysis was used to assess the expression of the immediate early genes, c-fos and c-jun, in all cell populations. No change in c-fos transcript levels were detected after 20 min exposure at each field intensity (20 min was the only time period at which c-fos message could be detected consistently). Transcript levels for c-jun were altered only after 20 min exposure to 9 mW/cm2 (average 38% decrease). Bioelectromagnetics 18:223-229, 1997. © 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
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    DNA synthesis and cell proliferation in C6 glioma and primary glial cells exposed to a 836.55 MHz modulated radiofrequency field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 230-236 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic fields ; tumor promotion ; brain tumor ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We have tested the hypothesis that modulated radiofrequency (RF) fields may act as a tumor-promoting agent by altering DNA synthesis, leading to increased cell proliferation. In vitro tissue cultures of transformed and normal rat glial cells were exposed to an 836.55 MHz, packet-modulated RF field at three power densities: 0.09, 0.9, and 9 mW/cm2, resulting in specific absorption rates (SARs) ranging from 0.15 to 59 μW/g. TEM-mode transmission-line cells were powered by a prototype time-domain multiple-access (TDMA) transmitter that conforms to the North American digital cellular telephone standard. One sham and one energized TEM cell were placed in standard incubators maintained at 37 °C and 5% CO2. DNA synthesis experiments at 0.59-59 μW/g SAR were performed on log-phase and serum-starved semiquiescent cultures after 24 h exposure. Cell growth at 0.15-15 μW/g SAR was determined by cell counts of log-phase cultures on days 0, 1, 5, 7, 9, 12, and 14 of a 2 week protocol. Results from the DNA synthesis assays differed for the two cell types. Sham-exposed and RF-exposed cultures of primary rat glial cells showed no significant differences for either log-phase or serum-starved condition. C6 glioma cells exposed to RF at 5.9 μW/g SAR (0.9 mW/cm2) exhibited small (20-40%) significant increases in 38% of [3H]thymidine incorporation experiments. Growth curves of sham and RF-exposed cultures showed no differences in either normal or transformed glial cells at any of the power densities tested. Cell doubling times of C6 glioma cells [sham (21.9 ± 1.4 h) vs. field (22.7 ± 3.2 h)] also demonstrated no significant differences that could be attributed to altered DNA synthesis rates. Under these conditions, this modulated RF field did not increase cell proliferation of normal or transformed cultures of glial origin. Bioelectromagnetics 18:230-236, 1997. © 1997 Wiley-Liss, Inc.
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    Focus formation of C3H/10T1/2 cells and exposure to a 836.55 MHz modulated radiofrequency field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 237-243 
    Details
    ISSN: 0197-8462
    Keywords: radiofrequency electromagnetic fields ; C3H/10T1/2 fibroblasts ; tumor promotion ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Disruption of communication between transformed cells and normal cells is involved in tumor promotion. We have tested the hypothesis that exposures to radiofrequency (RF) fields using a form of digital modulation (TDMA) and a chemical tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), are copromoters that enhance focus formation of transformed cells in coculture with parental C3H/10T1/2 murine fibroblasts. RF field exposures did not influence TPA's dose-dependent promotion of focus formation in coculture. Cell cultures were exposed to an 836.55 MHz TDMA-modulated field in TEM transmission line chambers, with incident energies that simulated field intensities at a user's head. Specific absorption rates (SARs) of 0.15, 1.5, and 15 μW/g were used during each digital packet, and the packet frequency was 50/s. The TEM chambers were placed in a commercial incubator at 37 °C and 95% humidity/5% CO2. The RF field exposures were in a repeating cycle, 20 min on, 20 min off, 24 h/day for 28 days. At 1.5 μW/g, TPA-induced focus formation (at 10, 30, and 50 ng/ml) was not significantly different in RF-exposed cultures compared to parallel sham-exposed cultures in ten independent experiments in terms of the number, density, and area of foci. Similarly, at 0.15 and 15.0 μW/g, in two and four experiments, respectively, RF exposure did not alter TPA-induced focus formation. The findings support a conclusion that repeated exposures to this RF field do not influence tumor promotion in vitro, based on the RF field's inability to enhance TPA-induced focus formation. Bioelectromagnetics 18:237-243, 1997 © 1997 Wiley-Liss, Inc.
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    What is the time scale of magnetic field interaction in biological systems? (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 244-249 
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    ISSN: 0197-8462
    Keywords: extremely-low-frequency magnetic fields ; free-radical mechanism ; ion-oscillator models ; ion-resonance models ; magnetotransduction ; AC/DC combinations ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: An experimental test constraining the intrinsic time scale of a primary physical mechanism that detects extremely-low-frequency (ELF) magnetic fields in biological systems is proposed. The suggested test postulates that a transductive mechanism operating on time scales much shorter than the period of an applied magnetic field cannot obtain any information about the exposure conditions other than the absolute magnitude of the field. By generating field exposures that differ in their vector properties but are equivalent in their time-varying absolute amplitude, it is possible to differentiate between two broad classes of mechanisms: 1) those with intrinsic time scales comparable with or longer than those of the external influence, and 2) those that are much faster than the period of the applied field. The hypothesis assumes an experimental model proven to respond to magnetic fields and sensitive to a change of about a factor of two in one of the field parameters (AC, DC amplitude or frequency). The case of general linearly polarized fields is discussed, and an analytical solution for the case of perpendicular AC/DC fields is given. Bioelectromagnetics 18:244-249, 1997 © 1997 Wiley-Liss, Inc.
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    Effects of low frequency pulsed electrical current on keratinocytes in vitro (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 250-254 
    Details
    ISSN: 0197-8462
    Keywords: pulsed current ; electrical stimulation ; wound healing ; epidermal repair ; keratinocytes ; cellular differentiation ; cellular proliferation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of low frequency pulsed electrical current on epidermal repair in vitro were examined. Charge-balanced current stimuli proposed for chronic wound treatment were tested on skin keratinocytes cultured at an air-liquid interface on dead human dermis. Results imply that the balance between proliferation and differentiation in electrically treated samples is significantly modified in favor of differentiation. More advanced differentiation, shown through epidermal histology, was obtained in cultures exposed to electrical current, whereas the culture growth, the result of keratinocyte migration and proliferation, was greater in control samples. Bioelectromagnetics 18:250-254, 1997. © 1997 Wiley-Liss, Inc.
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    Applied DC magnetic fields cause alterations in the time of cell divisions and developmental abnormalities in early sea urchin embryos (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 255-263 
    Details
    ISSN: 0197-8462
    Keywords: sea urchin ; static magnetic field ; gastrulation ; development ; mitotic cycle ; teratogenic effects ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Most work on magnetic field effects focuses on AC fields. The present study demonstrates that exposure to medium-strength (10 mT-0.1 T) static magnetic fields can alter the early embryonic development of two species of sea urchin embryos. Batches of fertilized eggs from two species of urchin were exposed to fields produced by permanent magnets. Samples of the continuous cultures were scored for the timing of the first two cell divisions, time of hatching, and incidence of exogastrulation. It was found that static fields delay the onset of mitosis in both species by an amount dependent on the exposure timing relative to fertilization. The exposure time that caused the maximum effect differed between the two species. Thirty millitesla fields, but not 15 mT fields, caused an eightfold increase in the incidence of exogastrulation in Lytechinus pictus, whereas neither of these fields produced exogastrulation in Strongylocentrotus purpuratus. Bioelectromagnetics 18:255-263, 1997. © 1997 Wiley-Liss, Inc.
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    Distributions of measurement errors for single-axis magnetic field meters during measurements near appliances (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 273-276 
    Details
    ISSN: 0197-8462
    Keywords: coil probe ; dipole field ; magnetic field ; measurement uncertainty ; power frequency ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Comparisons are made between the average magnetic flux density as it would be measured with a single-axis coil probe and the flux density at the center of the probe, assuming that the probe is oriented to measure the maximum field at that point. Probability distributions of the differences between the two quantities are calculated assuming a dipole magnetic field and are found to be asymmetric. The distributions are used to estimate the uncertainty for maximum magnetic field measurements at distances that are large compared with the dimensions of the field source. Bioelectromagnetics 18:273-276, 1997. © 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
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    Effects of low-intensity AC and/or DC electromagnetic fields on cell attachment and induction of apoptosis (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 264-272 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic fields ; cell adhesion ; osteoprogenitor cells ; fibroblast cells ; in vitro experiments ; apoptosis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Rat tendon fibroblast (RTF) and rat bone marrow (RBM) osteoprogenitor cells were cultured and exposed to AC and/or DC magnetic fields in a triaxial Helmholtz coil in an incubator for up to 13 days. The AC fields were at 60 and 1000 Hz and up to 0.25 mT peak to peak, and the DC fields were up to 0.25 mT. At various combinations of field strengths and frequencies, AC and/or DC fields resulted in extensive detachment of preattached cells and prevented the normal attachment of cells not previously attached to substrates. In addition, the fields resulted in altered cell morphologies. When RTF and RBM cells were removed from the fields after several days of exposure, they partially reattached and assumed more normal morphologies. An additional set of experiments described in the Appendix corroborates these findings and also shows that low-frequency EMF also initiates apoptosis, i.e., programmed cell death, at the onset of cell detachment. Taken together, these results suggest that the electromagnetic fields result in significant alterations in cell metabolism and cytoskeleton structure. Further work is required to determine the relative effect of the electric and magnetic fields on these phenomena. The research has implications for understanding the role of fields in affecting bone healing in fracture nonunions, in cell detachment in cancer metastasis, and in the effect of EMF on organisms generally. Bioelectromagnetics 18:264-272, 1997. © Wiley-Liss, Inc.
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    ELF magnetic field exposure system with feedback-controlled disturbance rejection (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 299-306 
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    ISSN: 0197-8462
    Keywords: ELF magnetic field exposure systems ; feedback control ; disturbance rejection ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Extremely low-frequency (ELF) magnetic field exposure systems are usually subject to field disturbances induced by external sources. Here, a method for designing a feedback control system for cancelling the effect of external ELF magnetic field disturbances on the magnetic field over the exposure area is presented. This method was used in the design of a feedback-controlled exposure system for an inverted microscope stage. The effectiveness of the proposed feedback control system for disturbance rejection was verified experimentally and by means of computer simulation. Bioelectromagnetics 18:299-306, 1997. © 1997 Wiley-Liss, Inc.
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    Amino acid concentrations in hypothalamic and caudate nuclei during microwave-induced thermal stress: Analysis by microdialysis (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 277-283 
    Details
    ISSN: 0197-8462
    Keywords: amino acids ; electromagnetic fields ; high-pressure liquid chromatography ; neurochemistry ; radiofrequency radiation ; thermoregulation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Exposure to radiofrequency radiation (RFR) may produce thermal responses. Extracellular amino acid concentrations in the hypothalamus (Hyp) and caudate nucleus (CN) were measured by using in vivo microdialysis before and during exposure to RFR. Under urethane anesthetic, each rat was implanted stereotaxically with a nonmetallic microdialysis probe and temperature probe guides and then placed in the exposure chamber. The rat laid on its right side with its head and neck placed directly under the wave guide. Temperature probes were placed in the left brain, right brain, face (subcutaneously), left tympanum, and rectum. Each microdialysis sample was collected over a 20 min period. The microdialysis probe was perfused for 2 h before the rat was exposed to 5.02 GHz radiation (10 μs pulse width, 1000 pulses/s). The right and left sides of the brain were maintained at approximately 41.2 and 41.7 °C, respectively, throughout a 40 min exposure period. Initially when the brain was being heated to these temperatures, the time-averaged specific absorption rates (SARs) for the right and left sides of the brain were 29 and 40 W/kg, respectively. Concentrations of aspartic acid, glutamic acid, serine, glutamine, and glycine in dialysate were determined by using high-pressure liquid chromatography with electrochemical detection. In the Hyp and CN, the concentrations of aspartic acid, serine, and glycine increased significantly during RFR exposure (P 〈 .05). These results indicate that RFR-induced thermal stress produces a general change in the amino acid concentrations that is not restricted to thermoregulatory centers. Changes in the concentrations of glutamic acid (Hyp, P = .16; CN, P = .34) and glutamine (Hyp, P = .13; CN, P = .10) were not statistically significant. Altered amino acid concentrations may reveal which brain regions are susceptible to damage in response to RFR-induced thermal stress. Bioelectromagnetics 18:277-283, 1997. © 1997 Wiley-Liss, Inc.
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    Effects of weak microwave fields amplitude modulated at ELF on EEG of symmetric brain areas in rats (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 293-298 
    Details
    ISSN: 0197-8462
    Keywords: MW radiation ; computerized time-averaging ; brain hemispheric asymmetry ; EEG ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Averaged electroencephalogram (EEG) frequency spectra were studied in eight unanesthetized and unmyorelaxed adult male rats with chronically implanted carbon electrodes in symmetrical somesthetic areas when a weak (0.1-0.2 mW/cm) microwave (MW, 945 MHz) field, amplitude-modulated at extremely low frequency (ELF) (4 Hz), was applied. Intermittent (1 min “On,” 1 min “Off”) field exposure (10-min duration) was used. Hemispheric asymmetry in frequency spectra (averaged data for 10 or 1 min) of an ongoing EEG was characterized by a power decrease in the 1.5-3 Hz range on the left hemisphere and by a power decrease in the 10-14 and 20-30 Hz ranges on the right hemisphere. No differences between control and exposure experiments were shown under these routines of data averaging. Significant elevations of EEG asymmetry in 10-14 Hz range were observed during the first 20 s after four from five onsets of the MW field, when averaged spectra were obtained for every 10 s. Under neither control nor pre- and postexposure conditions was this effect observed. These results are discussed with respect to interaction of MW fields with the EEG generators. Bioelectromagnetics 18:293-298, 1997. © 1997 Wiley-Liss, Inc.
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    Light-dependent and -independent behavioral effects of extremely low frequency magnetic fields in a land snail are consistent with a parametric resonance mechanism (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 284-291 
    Details
    ISSN: 0197-8462
    Keywords: biological effects of ELF magnetic fields ; attenuation of opioid analgaesia ; light-dependent magnetic field effects ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Exposure to extremely low frequency (ELF) magnetic fields has been shown to attenuate endogenous opioid peptide mediated antinociception or “analgaesia” in the terrestrial pulmonate snail, Cepaea nemoralis. Here we examine the roles of light in determining this effect and address the mechanisms associated with mediating the effects of the ELF magnetic fields in both the presence and absence of light. Specifically, we consider whether the magnetic field effects involve an indirect induced electric current mechanism or a direct effect such as a parametric resonance mechanism (PRM). We exposed snails in both the presence and absence of light at three different frequencies (30, 60, and 120 Hz) with static field values (BDC) and ELF magnetic field amplitude (peak) and direction (BAC) set according to the predictions of the PRM for Ca2+. Analgaesia was induced in snails by injecting them with an enkephalinase inhibitor, which augments endogenous opioid (enkephalin) activity. We found that the magnetic field exposure reduced this opioid-induced analgaesia significantly more if the exposure occurred in the presence rather than the absence of light. However, the percentage reduction in analgaesia in both the presence and absence of light was not dependent on the ELF frequency. This finding suggests that in both the presence and the absence of light the effect of the ELF magnetic field was mediated by a direct magnetic field detection mechanism such as the PRM rather than an induced current mechanism. Bioelectromagnetics 18:284-291, 1997. © 1997 Wiley-Liss, Inc.
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    Body heating induced by sub-resonant (350 MHz) microwave irradiation: Cardiovascular and respiratory responses in anesthetized rats (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 335-338 
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    ISSN: 0197-8462
    Keywords: radiofrequency radiation ; heart rate ; blood pressure ; cardiovascular system ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: These experiments were designed to investigate the effects of sub-resonant microwave (MW) exposure (350 MHz, E orientation, average power density 38 mW/cm2, average whole-body specific absorption rate 13.2 W/kg) on selected physiological parameters. The increase in peripheral body temperature during 350 MHz exposure was greater than that in earlier experiments performed at 700 MHz (resonance). Heart rate and mean arterial blood pressure were significantly elevated during a 1 °C increase in colonic temperature due to 350 MHz exposure; respiratory rate showed no significant change. The results are consistent with other investigators' reports comparing sub-resonance exposures with those at resonance and above. Bioelectromagnetics 18:335-338, 1997. © 1997 Wiley-Liss, Inc.
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    Study of magnetic fields from power-frequency current on water lines (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 307-316 
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    ISSN: 0197-8462
    Keywords: residential magnetic fields ; power net currents ; ground currents ; water lines ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The magnetic fields from power-frequency current flowing on water lines were investigated in a new approach that involved an area-wide survey in a small town. Magnetic fields were measured outside the residence under power cables and over water lines, and each residence was characterized as to whether it received water from a private well or the municipal water system. The magnetic field data revealed two statistical modes when they were related to water supply type. The data also showed that in the case of the high mode, the magnetic field remained constant along the line formed by power drop wires, at the back of the house, and the water hookup service, in front of the house, all the way to the street. The patterns are explained by the coincidence of measurement points and the presence of net current flowing on power mains, power drop conductors, residential plumbing, water service hookups, and water mains. These patterns, together with other characteristics of this magnetic field source, such as the gradual spatial fall-off of this field and the presence of a constant component in the time sequence, portray a magnetic field more uniform and constant in the residential environment than has been thought to exist. Such characteristics make up for the weakness of the source and make net current a significant source of exposure in the lives of individuals around the house, when human exposure to magnetic fields is assumed to be a cumulative effect over time. This, together with the bimodal statistical distribution of the residential magnetic field (related to water supply type), presents opportunities for retrospective epidemiological analysis. Water line type and its ability to conduct power-frequency current can be used as the historical marker for a bimodal exposure inference, as Wertheimer et al. have shown. Bioelectromagnetics 18:307-316, 1997. © 1997 Wiley-Liss, Inc.
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    The role of temporal sensing in bioelectromagnetic effects (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 388-395 
    Details
    ISSN: 0197-8462
    Keywords: ornithine decarboxylase ; cell culture ; 60 Hz fields ; “averaging” time ; “memory” time ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Experiments were conducted to see whether the cellular response to electromagnetic (EM) fields occurs through a detection process involving temporal sensing. L929 cells were exposed to 60 Hz magnetic fields and the enhancement of ornithine decarboxylase (ODC) activity was measured to determine cellular response to the field. In one set of experiments, the field was turned alternately off and on at intervals of 0.1 to 50 s. For these experiments, field coherence was maintained by eliminating the insertion of random time intervals upon switching. Intervals ≥ 1 s produced no enhancement of ODC activity, but fields switched at intervals ≥ 10 s showed ODC activities that were enhanced by a factor of approximately 1.7. These data indicate that it is the interval over which field parameters (e.g., amplitude or frequency) remain constant, rather than the interval over which the field is coherent, that is critical to cellular response to an EMF. In a second set of experiments, designed to determine how long it would take for cells to detect a change in field parameters, the field was interrupted for brief intervals (25-200 ms) once each second throughout exposure. In this situation, the extent of EMF-induced ODC activity depended upon the duration of the interruption. Interruptions ≥ 100 ms were detected by the cell as shown by elimination of field-induced enhancement of ODC. That two time constants (0.1 and 10 s) are involved in cellular EMF detection is consistent with the temporal sensing process associated with bacterial chemotaxis. By analogy with bacterial temporal sensing, cells would continuously sample and average an EM field over intervals of about 0.1 s (the “averaging” time), storing the averaged value in memory. The cell would compare the stored value with the current average, and respond to the EM field only when field parameters remain constant over intervals of approximately 10 s (the “memory” time). Bioelectromagnetics 18:388-395, 1997. © 1997 Wiley-Liss, Inc.
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    Influence of human model resolution on computed currents induced in organs by 60-Hz magnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 478-490 
    Details
    ISSN: 0197-8462
    Keywords: organ dosimetry ; low-frequency magnetic induction ; numerical modelling ; FDTD calculations ; impedance method ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of human body model resolution on computed electric fields induced by 60 Hz uniform magnetic fields are investigated. A recently-developed scalar potential finite difference code for low-frequency electromagnetic computations is used to model induction in two anatomically realistic human body models. The first model consists of 204 290 cubic voxels with 7.2-mm edges, while the second comprises 1 639 146 cubic voxels with 3.6-mm edges. Calculations on the lower-resolution model using, for example, the finite difference time domain or impedance methods, push the capabilities of workstations. The scalar method, in contrast, can handle the higher-resolution model using comparable resources. The results are given in terms of average and maximum electric field intensities and current density magnitudes in selected tissues and organs. Although the lower-resolution model provides generally acceptable results, there are important differences that make the added computational burden of the higher-resolution calculations worthwhile. In particular, the higher-resolution modelling generally predicts peak electric fields intensities and current density magnitudes that are slightly higher than those computed using the lower-resolution modelling. The differences can be quite large for small organs such as glands. Bioelectromagnetics 18:478-490, 1997. © 1997 Wiley-Liss, Inc.
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    Bioelectric potential gradients may initiate cell cycling: ELF and zeta potential gradients may mimic this effect (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 341-348 
    Details
    ISSN: 0197-8462
    Keywords: wound potential gradient ; ELF field ; zeta potential ; in situ electrophoresis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: When a number of experimental studies in bioelectromagnetics were reviewed, those in which weak, exogenous extremely low frequency (ELF) fields were applied in fixed juxtaposition to their target tissues, were found to initiate mitogenesis or mitogenesis-related signals more successfully than when the target tissue moved freely during the irradiation. It is suggested that ELF fields in fixed juxtaposition to their target tissue and implanted foreign bodies or endogenous tissues with a significant zeta potential, mimic bioelectric fields generated at wounds. When the potential is high enough, they assist healing by moving cells into the wound and stimulating quiescent cells at the wound margin to cycle. Electrophoresis may help the initial migration of cells into the wound to form a clot, and migration of fibroblasts and epithelial cells from the wound margin. When exposed for a long time in a fixed juxtaposition to a potential gradient too weak to show in situ microelectrophoresis along the cell membrane surface, surface particles may coalesce to form microclusters, where like-charged surface particles are in close proximity, and growth factor receptor oligomerization and other cycle-initiating reactions are facilitated. Bioelectromagnetics 18:341-348, 1997. © 1997 Wiley-Liss, Inc.
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    No short-term effects of high-frequency electromagnetic fields on the mammalian pineal gland (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 376-387 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic fields ; UHF-frequency band ; exposure system ; pineal gland ; melatonin ; synaptic ribbons ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: There is ample experimental evidence that changes of earth-strength static magnetic fields, pulsed magnetic fields, or alternating electric fields (60 Hz) depress the nocturnally enhanced melatonin synthesis of the pineal gland of certain mammals. No data on the effects of high-frequency electromagnetic fields on melatonin synthesis is available. In the present study, exposure to 900 MHz electromagnetic fields [0.1 to 0.6 mW/cm2, approximately 0.06 to 0.36 W/kg specific absorption rate (SAR) in rats and 0.04 W/kg in Djungarian hamsters; both continuous and/or pulsed at 217 Hz, for 15 min to 6 h] at day or night had no notable short-term effect on pineal melatonin synthesis in male and female Sprague-Dawley rats and Djungarian hamsters. Pineal synaptic ribbon profile numbers (studied in rats only) were likewise not affected. The 900 MHz electromagnetic fields, unpulsed or pulsed at 217 Hz, as applied in the present study, have no short-term effect on the mammalian pineal gland. Bioelectromagnetics 18:376-387, 1997. © 1997 Wiley-Liss, Inc.
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    The effects of 50 Hz magnetic field exposure on dimethylbenz(α)anthracene induced thymic lymphoma/leukemia in mice (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 360-364 
    Details
    ISSN: 0197-8462
    Keywords: extremely-low-frequency (ELF) ; thymic lymphoma/leukemia ; dimethylbenz-(α)anthracene (DMBA) ; tumor promotion ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Several epidemiological investigations have suggested an increased incidence of lymphoma, leukemia, and brain tumor in residents living near power transmission lines. However, some observers failed to confirm such a positive correlation. To evaluate the effects of extremely low frequency (ELF) magnetic fields on leukemogenesis, an experimental animal model was used, in which thymic lymphoma/leukemia was induced by dimethylbenz(α)anthracene (DMBA) injected subcutaneously into the interscapular region of newborn mice within 24 h after birth. Beginning at the second week of age, 165 mice were exposed to 50 Hz magnetic field at 1 mT, 3 h/day, 6 days/week for 16 weeks, and 155 animals exposed to sham conditions. All surviving animals were killed by cervical dislocation at the age of 32 weeks and were examined pathologically. The results showed that the incidences of advanced thymic lymphoma, complicated with lymphomatous leukemia, were 21.8 and 23.9% in the two groups, respectively, without statistically significant differences. But dense metastatic infiltration by lymphoma cells into liver in the field exposure group greater (50%) than that in the sham-exposure group (16.2%) was observed (χ2 = 9.847, P 〈 0.01). To determine whether ELF acts as a tumor promoter, further experiments are required. Bioelectromagnetics 18:360-364, 1997. © 1997 Wiley-Liss, Inc.
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    Bioeffects induced by exposure to microwaves are mitigated by superposition of ELF noise (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 422-430 
    Details
    ISSN: 0197-8462
    Keywords: cellular phones ; EMFs ; biological effects ; amplitude modulation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We have previously demonstrated that microwave fields, amplitude modulated (AM) by an extremely low-frequency (ELF) sine wave, can induce a nearly twofold enhancement in the activity of ornithine decarboxylase (ODC) in L929 cells at SAR levels of the 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 ODC 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 60 Hz 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 μT. 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 μT. With the DAMPS digital cellular phone signal, complete inhibition occurred with noise levels at or above 5 μT. 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.
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    The effect of pulsed and sinusoidal magnetic fields on the morphology of developing chick embryos (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 431-438 
    Details
    ISSN: 0197-8462
    Keywords: ELF ; embryonic development ; PMF ; abnormalities ; 60 Hz ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Several investigators have reported robust, statistically significant results that indicate that weak (∼ 1 μT) magnetic fields (MFs) increase the rate of morphological abnormalities in chick embryos. However, other investigators have reported that weak MFs do not appear to affect embryo morphology at all. We present the results of experiments conducted over five years in five distinct campaigns spanning several months each. In four of the campaigns, exposure was to a pulsed magnetic field (PMF); and in the final campaign, exposure was to a 60 Hz sinusoidal magnetic field (MF). A total of over 2500 White Leghorn chick embryos were examined. When the results of the campaigns were analyzed separately, a range of responses was observed. Four campaigns (three PMF campaigns and one 60 Hz campaign) exhibited statistically significant increases (P ≥ 0.01), ranging from 2-fold to 7-fold, in the abnormality rate in MF-exposed embryos. In the remaining PMF campaign, there was only a slight (roughly 50%), statistically insignificant (P = 0.2) increase in the abnormality rate due to MF exposure. When the morphological abnormality rate of all of the PMF-exposed embryos was compared to that of all of the corresponding control embryos, a statistically significant (P ≥ .001) result was obtained, indicating that PMF exposure approximately doubled the abnormality rate. Likewise, when the abnormality rate of the sinusoid-exposed embryos was compared to the corresponding control embryos, the abnormality rate was increased (approximately tripled). This robust result indicates that weak EMFs can induce morphological abnormalities in developing chick embryos. We have attempted to analyze some of the confounding factors that may have contributed to the lack of response in one of the campaigns. The genetic composition of the breeding stock was altered by the breeder before the start of the nonresponding campaign. We hypothesize that the genetic composition of the breeding stock determines the susceptibility of any given flock to EMF-induced abnormalities and therefore could represent a confounding factor in studies of EMF-induced bioeffects in chick embryos. Bioelectromagnetics 18:431-438, 1997. © 1997 Wiley-Liss, Inc.
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    Melatonin and a spin-trap compound block radiofrequency electromagnetic radiation-induced DNA strand breaks in rat brain cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 446-454 
    Details
    ISSN: 0197-8462
    Keywords: radiofrequency electromagnetic radiation (RER) ; brain cells ; DNA single- and double-strand breaks ; melatonin ; N-tert-butyl-α-phenylnitrone (PNB) ; free radicals ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Effects of in vivo microwave exposure on DNA strand breaks, a form of DNA damage, were investigated in rat brain cells. In previous research, we have found that acute (2 hours) exposure to pulsed (2 μsec pulses, 500 pps) 2450-MHz radiofrequency electromagnetic radiation (RFR) (power density 2 mW/cm2, average whole body specific absorption rate 1.2 W/kg) caused an increase in DNA single- and double-strand breaks in brain cells of the rat when assayed 4 hours post exposure using a microgel electrophoresis assay. In the present study, we found that treatment of rats immediately before and after RFR exposure with either melatonin (1 mg/kg/injection, SC) or the spin-trap compound N-tert-butyl-α-phenylnitrone (PBN) (100 mg/kg/injection, IP) blocks this effect of RFR. Since both melatonin and PBN are efficient free radical scavengers, it is hypothesized that free radicals are involved in RFR-induced DNA damage in the brain cells of rats. Since cumulated DNA strand breaks in brain cells can lead to neurodegenerative diseases and cancer and an excess of free radicals in cells has been suggested to be the cause of various human diseases, data from this study could have important implications for the health effects of RFR exposure. Bioelectromagnetics 18:446-454, 1997. © 1997 Wiley-Liss, Inc.
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    Intramembrane protein distribution in cell cultures is affected by 50 Hz pulsed magnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 463-469 
    Details
    ISSN: 0197-8462
    Keywords: IMP ; PMF ; freeze-fracture ; bone repair ; image analysis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Intramembrane proteins (IMP) represent a class of proteins located in the lipid bilayer of the cell membrane which function as ion channels, enzymes or receptors. Since it has been argued that biological effects of extremely low frequency (ELF) electromagnetic fields are mediated by plasma membrane, this work was designed to study the possible effects of 50 Hz pulsed magnetic fields (PMF) of the type used to stimulate bone repair, on the distribution of IMP in the plasma membrane of Swiss NIH 3T3 fibroblasts. Evaluations were based on the calculation of a distribution factor, which allows discrimination between random, regular and clustered distribution of IMP, in electron microscope images of freeze-fractured membranes. The results indicate that cells exposed to PMF for more than two hours have a significant clustering of the IMP distribution compared to control unexposed cells. Bioelectromagnetics 18:463-469, 1997. © 1997 Wiley-Liss, Inc.
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    Influence of extremely low frequency electromagnetic fields on the swimming behavior of ciliates (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 491-498 
    Details
    ISSN: 0197-8462
    Keywords: Paramecium ; Loxodes ; Tetrahymena ; pawn mutant ; ion channels ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Different species of ciliates (Paramecium biaurelia, Loxodes striatus, Tetrahymena thermophila) have been taken as model systems to study the effects of extremely low-frequency electromagnetic fields (50 Hz, 0.5-2.0 mT) on the cellular level. A dose-dependent increase in the mean swimming velocity and a decrease in the linearity of cell tracks were observed in all wild-type cells. In contrast, field-exposure did not increase the number of directional turns of the Paramecium tetraurelia pawn mutant (d4-500r), which is characterized by defective Ca2+-channels. The described changes indicate a direct effect of low frequency electromagnetic fields on the transport mechanisms of the cell membrane for ions controlling the motile activity of cilia. Bioelectromagnetics 18:491-498, 1997. © 1997 Wiley-Liss, Inc.
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    Exposure of welders and other metal workers to ELF magnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 470-477 
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    ISSN: 0197-8462
    Keywords: magnetic fields ; welding processes ; shipyard ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This study assessed exposure to extremely low frequency (ELF) magnetic fields of welders and other metal workers and compared exposure from different welding processes. Exposure to ELF magnetic fields was measured for 50 workers selected from a nationwide cohort of metal workers and 15 nonrandomly selected full-time welders in a shipyard. The measurements were carried out with personal exposure meters during 3 days of work for the metal workers and 1 day of work for the shipyard welders. To record a large dynamic range of ELF magnetic field values, the measurements were carried out with “high/low” pairs of personal exposure meters. Additional measurements of static magnetic fields at fixed positions close to welding installations were done with a Hall-effect fluxmeter. The total time of measurement was 1273 hours. The metal workers reported welding activity for 5.8% of the time, and the median of the work-period mean exposure to ELF magnetic fields was 0.18 μT. DC metal inert or active gas welding (MIG/MAG) was used 80% of the time for welding, and AC manual metal arc welding (MMA) was used 10% of the time. The shipyard welders reported welding activity for 56% of the time, and the median and maximum of the workday mean exposure to ELF magnetic fields was 4.70 and 27.5 μT, respectively. For full-shift welders the average workday mean was 21.2 μT for MMA welders and 2.3 μT for MIG/MAG welders. The average exposure during the effective time of welding was estimated to be 65 μT for the MMA welding process and 7 μT for the MIG/MAG welding process. The time of exposure above 1 μT was found to be a useful measure of the effective time of welding. Large differences in exposure to ELF magnetic fields were found between different groups of welders, depending on the welding process and effective time of welding. MMA (AC) welding caused roughly 10 times higher exposure to ELF magnetic fields compared with MIG/MAG (DC) welding. The measurements of static fields suggest that the combined exposure to static and ELF fields of MIG/MAG (DC) welders and the exposure to ELF fields of MMA (AC) welders are roughly of the same level. Bioelectromagnetics 18:470-477, 1997. © 1997 Wiley-Liss, Inc.
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    Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 499-505 
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    ISSN: 0197-8462
    Keywords: RF radiation ; microwave radiation ; stress proteins ; heat shock proteins ; mammalian cells ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The induction of stress proteins in HeLa and CHO cells was investigated following a 2 h exposure to radiofrequency (RF) or microwave radiation. Cells were exposed or sham exposed in vitro under isothermal (37 ± 0.2 °C) conditions. HeLa cells were exposed to 27- or 2450 MHz continuous wave (CW) radiation at a specific absorption rate (SAR) of 25 W/kg. CHO cells were exposed to CW 27 MHz radiation at a SAR of 100 W/kg. Parallel positive control studies included 2 h exposure of HeLa or CHO cells to 40 °C or to 45 μM cadmium sulfate. Stress protein induction was assayed 24 h after treatment by electrophoresis of whole-cell extracted protein labeled with [35S]-methionine. Both cell types exhibited well-characterized responses to the positive control stresses. Under these exposure conditions, neither microwave nor RF radiation had a detectable effect on stress protein induction as determined by either comparison of RF-exposed cells with sham-exposed cells or comparison with heat-stressed or Cd++ positive control cells. Bioelectromagnetics 18:499-505, 1997. © 1997 Wiley-Liss, Inc.
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    Vertical circularly polarized ELF magnetic fields and induced electric fields in culture mediaThis article is a US Government work and, as such, is in the public domain in the United States of America. (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 524-526 
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    ISSN: 0197-8462
    Keywords: exposure parameters ; in vitro ; power frequency ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Some properties of induced electric fields in cell culture media produced by vertical circularly polarized magnetic fields are examined. The described geometry is not advantageous for determining effects that may be attributable to induced electric fields or currents. Bioelectromagnetics 18:524-526, 1997. Published 1997 Wiley-Liss, Inc.
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    Biological effects of continuous exposure of embryos and young chickens to electromagnetic fields emitted by video display units (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 514-523 
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    ISSN: 0197-8462
    Keywords: embryonic development ; chicken ; VDU ; electromagnetic field ; immuno-neuroendocrinology ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of continuous exposure of embryos and young chickens to electromagnetic fields (EMFs) emitted by video display units (VDUs) were investigated. Embryos and brood were continuously exposed during embryonic and postembryonic phases to EMFs emitted by two types of VDU (TV or computer). Embryonic mortality was evaluated in three independent experiments. Young chickens were immunized three times by porcine thyroglobulin (Tg). Blood samples were assayed after each immunization for specific anti-Tg antibodies (IgG), plasma corticosterone (CORT), and plasma melatonin (MLT). In the sham-exposed samples, embryonic death (10-33%) was restricted to the perinatal period and the IgG, CORT, and MLT responses of young chickens crested after the second immunization. Constant EMF exposure was accompanied by significantly increased fetal loss (47-68%) and markedly depressed levels of circulating anti-Tg IgG, CORT, and MLT. Collectively, these findings indicate that continuous exposure to EMFs, issuing from VDUs, adversely affects embryos and young chickens. Bioelectromagnetics 18:514-523, 1997. © 1997 Wiley-Liss, Inc.
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    Magnetic field effects on coenzyme B12-dependent enzymes: Validation of ethanolamine ammonia lyase results and extension to human methylmalonyl CoA mutase (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 506-513 
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    ISSN: 0197-8462
    Keywords: coenzyme B12 ; magnetic field effects ; enzyme mechanisms ; methylmalonyl-CoA mutase ; ethanolamine ammonia lyase ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Enzymes with radical-pair intermediates have been considered as a likely target for purported magnetic field effects in humans. The bacterial enzyme ethanolamine ammonia lyase and the human enzyme methylmalonyl-CoA mutase catalyze coenzyme B12-dependent rearrangement reactions. A common step in the mechanism of these two enzymes is postulated to be homolysis of the cobalt-carbon bond of the cofactor to generate a spin-correlated radical pair consisting of the 5′-deoxyadenosyl radical and cob(II)alamin [Ado· Cbl(II)]. Thus, the reactions catalyzed by these enzymes are expected to be sensitive to an applied magnetic field according to the same principles that control radical pair chemical reactions. The magnetic field effect on ethanolamine ammonia lyase reported previously has been corroborated independently in one of the authors' laboratory. However, neither the human nor the bacterial mutase from Propionibacterium shermanii exhibits a magnetic field effect that could be greater than about 15%, considering the error limit imposed by the uncertainty of the coupled assay. Our studies suggest that putative magnetic field effects on physiological processes are not likely to be mediated by methylmalonyl-CoA mutase. Bioelectromagnetics 18:506-513, 1997. © 1997 Wiley-Liss, Inc.
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    Comments on “resonance effect of millimeter waves in the power range from 10-19 to 3 × 10-3 W/cm2 on Escherichia coli cells at different concentrations,” Belyaev et al., Bioelectromagnetics, 17:312-321 (1996) (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 527-528 
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    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
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    Reply to comments of Osepchuk and Petersen (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 529-530 
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    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
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    Carcinogenicity test of 50 Hz sinusoidal magnetic fields in rats (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 531-540 
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    ISSN: 0197-8462
    Keywords: carcinogenicity ; rat ; magnetic field ; elf ; two-year bioassay ; lifetime exposures ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Male and female F344 rats, 48 per exposure group, were sham exposed (Group A) or exposed to 0.5 (Group B) and 5 mT (Group C) magnetic fields for two years. Animals were exposed from 5-109 weeks of age in SPF conditions according to the OECD test guideline No. 451. Average exposure was 22.6 hr/day. No significant differences in body weight and food consumption were observed between the sham and exposed groups. At the end of the exposure period, survival rates of the male rats were 73, 83, and 79%, and those of the females, 77, 79, and 75% for Groups A, B, and C, respectively, with no significant differences between groups. Differential counts of leukocytes were measured at the 52nd, 78th, and 104th weeks of exposure and no significant differences were observed between the exposure groups. All survivors were euthanized on schedule, and all the organs and tissues suspected of tumoral lesions were examined histopathologically. Incidences of mononuclear cell leukemia in the male and the female rats were 5, 4, 4 and 8, 6, 7 for Groups A, B and C, respectively; incidences of malignant lymphoma in the female rats were 0, 1 and 1. Neither significant increases nor acceleration of incidence of leukemia were observed. Incidences of brain and intracranial tumors did not increase in the exposed groups. Incidences of both benign and malignant neoplasms showed no significant difference between the exposed and sham exposed groups with one exception: fibroma of the subcutis in the male rats, which was considered not to be a statistically significant when evaluated with respect to the historical control data in our laboratory. Bioelectromagnetics 18:531-540, 1997. © Wiley-Liss, Inc.
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    Short cycles of both static and pulsed electromagnetic fields have no effect on the induction of cytokines by peripheral blood mononuclear cells (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 548-554 
    Details
    ISSN: 0197-8462
    Keywords: static electromagnetic field ; pulsed electromagnetic field ; interleukin-2 ; interferon γ ; tumor necrosis factor α ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We evaluated the effect of short cycles of static and pulsed electromagnetic field exposure on the eventual activation of peripheral blood mononuclear cells. The cells were subjected to three 15-min cycles of EMF, each exposure being followed by 105 min without a field, for a total of 6 hr. The results clearly demonstrate that the proliferative responses of both normal cells and cells stimulated with 1 μg/ml phytohemagglutinin were not distinguishable from control cells not exposed to EMF. Moreover, although the production of interleukin-2, interferon γ and tumor necrosis factor α increased during the first 48 hr of incubation, the values remained unchanged with respect to controls. This indicates that brief exposure to an electromagnetic field has no significant effect on peripheral blood mononuclear cells. The comparison between biological activity and the cytokine antigen present in our samples indicated that the recovery of antigen corresponded to an equal recovery of biological activity, suggesting the absence of either qualitative differences in these proteins or the impairment of transcriptional and translational processes. Bioelectromagnetics 18: 548-554, 1997. © 1997 Wiley-Liss, Inc.
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    Environmental magnetic fields inhibit the antiproliferative action of tamoxifen and melatonin in a human breast cancer cell line (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 555-562 
    Details
    ISSN: 0197-8462
    Keywords: MCF-7 ; tamoxifen ; melatonin ; magnetic fields ; cell proliferation ; human breast cancer cells ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We have previously reported that environmental-level magnetic fields (1.2 μT [12 milligauss], 60 Hz) block the growth inhibition of the hormone melatonin (10-9 M) on MCF-7 human breast cancer cells in vitro. We now report that the same 1.2 μT, 60 Hz magnetic fields significantly block the growth inhibitory action of pharmacological levels of tamoxifen (10-7 M). In biophysical studies we have taken advantage of Faraday's Law of Current Induction and tested whether the 1.2 μT magnetic field or the associated induced electric field is responsible for this field effect on melatonin and tamoxifen. We observe that the magnetic field component is associated with the field blocking effect on melatonin and tamoxifen function. To our knowledge the tamoxifen studies represent the first experimental evidence for an environmental-level magnetic field modification of drug interaction with human breast cancer cells. Together, these findings provide support to the theory that environmental-level magnetic fields can act to modify the action of a drug or hormone on regulation of cell proliferation. Melatonin and tamoxifen may act through different biological pathways to down-regulate cell growth, and further studies are required to identify a specific biological site of interaction for the 1.2 μT magnetic field. Bioelectromagnetics 18:555-562, 1997. Published 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
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    Summary of measured radiofrequency electric and magnetic fields (10 kHz to 30 GHz) in the general and work environment (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 563-577 
    Details
    ISSN: 0197-8462
    Keywords: radiofrequency ; microwave ; exposure ; environmental ; occupational ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We have plotted data from a number of studies on the range of radiofrequency (RF) field levels associated with a variety of environmental and occupational sources. Field intensity is shown in units of volts/meter (V/m) for electric field strength and amps/meter (A/m) for magnetic field strength. Duty factors, modulation frequencies, and modulation indices are also reported for some sources. This paper is organized into seven sections, each cataloging sources into appropriate RF frequency bands from very-low frequency (VLF) to super-high frequency (SHF), and covers frequencies from 10 kHz to 30 GHz. Sources included in this summary are the following: Coast Guard navigational transmitters, a Navy VLF transmitter, computer visual display terminals (VDTs), induction stoves or range tops, industrial induction and dielectric heaters, radio and television broadcast transmitters, amateur and citizens band (CB) transmitters, medical diathermy and electrosurgical units, mobile and handheld transmitters, cordless and cellular telephones, microwave ovens, microwave terrestrial relay and satellite uplinks, and police, air traffic, and aircraft onboard radars. For the sources included in this summary, the strongest fields are found near industrial induction and dielectric heaters, and close to the radiating elements or transmitter leads of high power antenna systems. Handheld transmitters can produce near fields of about 500 V/m at the antenna. Fields in the general urban environment are principally associated with radio and TV broadcast services and measure about 0.1 V/m root-mean-square (rms). Peak fields from air traffic radars sampled in one urban environment were about 10 V/m, 300 times greater than the rms value of 0.03 V/m when the duty factor associated with antenna rotation and pulsing are factored in. Bioelectromagnetics 18: 563-577, 1997. Published 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
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    Responses of human MG-63 osteosarcoma cell line and human osteoblast-like cells to pulsed electromagnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 541-547 
    Details
    ISSN: 0197-8462
    Keywords: electromagnetic field ; PEMF ; osteoblast-like cells ; MG-63 cell line ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We have studied the effects of low-energy, low-frequency pulsed electromagnetic fields (PEMF) on cell proliferation, in both human osteoblast-like cells obtained from bone specimens and in human MG-63 osteosarcoma cell line. Assessment of osteoblastic phenotype was performed both by immunolabeling with antiosteonectin antibody and by verifying the presence of parathyroid hormone receptors. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmholtz coils powered by a pulse generator (1.3 ms, 75 Hz) for different periods of time. [3H]-Thymidine incorporation was used to evaluate cell proliferation. Since it had previously been observed that the osteoblast proliferative response to PEMF exposure may also be conditioned by the presence of serum in the medium, experiments were carried out at different serum concentrations. [3H]-thymidine incorporation increases in osteoblast-like cells, when they are exposed to PEMF in the presence of 10% fetal calf serum (FCS). The greatest effect is observed after 24 hours of PEMF exposure. No effects on cell proliferation are observed when osteoblast-like cells are exposed to PEMF in the presence of 0.5% FCS or in a serum-free medium. On the other hand, PEMF-exposed MG-63 cells show increased cell proliferation either at 10% FCS, 0.5% FCS and in serum-free medium. Nevertheless, the maximum effect of PEMF exposure on MG-63 cell proliferation depends on the percentage of FCS in the medium. The higher the FCS concentration, the faster the proliferative response to PEMF exposure. Our results show that, although MG-63 cells display some similarity with human bone cells, their responses to PEMF's exposure are quite different from that observed in normal human bone cells. Bioelectromagnetics 18: 541-547, 1997. © 1997 Wiley-Liss, Inc.
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    A thermal model for human thresholds of microwave-evoked warmth sensations (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 578-583 
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    ISSN: 0197-8462
    Keywords: warmth threshold ; microwaves ; bioheat equation ; skin sensation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Human thresholds for skin sensations of warmth were measured at frequencies from 2.45 to 94 GHz. By solving the one-dimensional bioheat equation, we calculated the temperature increase at the skin surface or at a depth of 175 μm at incident power levels corresponding to the observed thresholds. The thermal analysis suggests that the thresholds correspond to a localized temperature increase of about 0.07 °C at and near the surface of the skin. We also found that, even at the highest frequency of irradiation, the depth at which the temperature receptors are located is not a relevant parameter, as long as it is within 0.3 mm of the surface. Over the time range of the simulation, the results of the thermal model are insensitive to blood flow, but sensitive to thermal conduction; and this sensitivity increases strongly with frequency. We conclude with an analysis of the effect of thermal conduction on surface temperature rise, which becomes a dominant factor at microwave frequencies over 10 GHz. Bioelectromagnetics 18:578-583, 1997. © 1997 Wiley-Liss, Inc.
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    Psychological effects of chronic exposure to 50 Hz magnetic fields in humans living near extra-high-voltage transmission lines (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 584-594 
    Details
    ISSN: 0197-8462
    Keywords: cross-sectional study ; psychological effects ; mental health ; electromagnetic fields ; powerlines ; dose-response ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The validity of several published investigations of the possibility that residential exposures to 50 Hz or 60 Hz electromagnetic fields might cause adverse psychological effects, such as suicide and depression, may have been limited by inadequate controlling for confounders or inadequate measurement of exposures. We investigated the relationships between magnetic field exposure and psychological and mental health variables while controlling for potential confounders and careful characterising individual magnetic field exposures. Five-hundred-and-forty adults living near transmission lines completed neuropsychological tests in major domains of memory and attentional functioning, mental health rating scales and other questionnaires. Magnetic field measurements were taken in each room occupied for at least one hour per day to provide an estimate of total-time-integrated exposure. The data were subjected to joint multivariate multiple regression analysis to test for a linear relation between field exposure and dependent variables, while controlling for effects of possible confounders. Performance on most memory and attention measures was unrelated to exposure, but significant linear dose-response relationships were found between exposure and some psychological and mental health variables. In particular, higher time-integrated exposure was associated with poorer coding-test performance and more adverse psychiatric symptomatology. These associations were found to be independent of participants' beliefs about effects of electromagnetic fields. Bioelectromagnetics 18:584-594, 1997. © 1997 Wiley-Liss, Inc.
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    Alterations of intracellular calcium concentration in mice neuroblastoma cells by electrical field and UVA (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 595-597 
    Details
    ISSN: 0197-8462
    Keywords: FURA2 ; Ca ions ; EMF ; UVA ; neuroblastoma ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: By using a FURA2 ratio imaging method, the intracellular free calcium concentration was investigated in cultured mice neuroblastoma cells under the influence of an amplitude-modulated (AM) field (5 kHz sine wave AM 16 Hz sinusoidal 800 V/m and 80 V/m), as well as of electric field pulses (300-ms unipolar pulses of 1000 V/m and 800 V/m, 5 pulses during 10 s and 50 pulses during 100 s). An increase in free intracellular calcium was found in about 50% of cells after field application, whereas in control experiments only about 20% of the cells showed similar increases. However, this effect depended on the amount of UV irradiation used for excitation of FURA2 fluorescence. Experiments with 1/30 to former total illumination no longer demonstrated an increase in control cells or in cells treated with AM fields. The number of cells showing calcium increase after the application of pulsed fields was reduced significantly. Therefore, the UV light itself, applied as double flashes for the fluorescence measurement, activates the cellular calcium regulation. These findings offer a possible explanation for the low reproducibility of field effects found in different laboratories, in which investigations were performed with different equipment using different intensities of UV excitation. Bioelectromagnetics 18:595-597, 1997. © 1997 Wiley-Liss, Inc.
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    Electrochemical treatment of tumor (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 1-1 
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    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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    Effects of direct current on dog liver: Possible mechanisms for tumor electrochemical treatment (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 2-7 
    Details
    ISSN: 0197-8462
    Keywords: pH ; ions ; protein ; anode ; cathode ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Mechanisms of tumor electrochemical treatment (ECT) were studied using normal dog liver. Five physical and chemical methods were used. Two platinum electrodes were inserted into an anesthetized dog's liver at 3 cm separation. A voltage of 8.5 V direct current (DC) at an average current of 30 mA was applied for 69 min; total charge was 124 coulombs. Concentrations of selected ions near the anode and cathode were measured. The concentrations of Na+ and K+ ions were higher around the cathode, whereas the concentration of Cl- ions was higher around the anode. Water contents and pH were determined near the anode and the cathode at the midpoint between the two electrodes and in an untreated area away from the electrodes. Hydration occurred around the cathode, and dehydration occurred around the anode. The pH values were 2.1 near the anode and 12.9 near the cathode. Spectrophotometric scans of the liver sample extract were obtained, and the released gases were identified by gas chromatography as chlorine at the anode and hydrogen at the cathode. These results indicate that a series of electrochemical reactions take place during ECT. The cell metabolism and its environment are severely disturbed. Both normal and tumor cells are rapidly and completely destroyed in this altered environment. We believe that the above reactions are the ECT mechanisms for treating tumors. Bioelectromagnetics 18:2-7, 1997. © 1997 Wiley-Liss, Inc.
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    Mechanism of action of weak electromagnetic field on ionic currents in aqueous solutions of amino acids (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 25-27 
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    ISSN: 0197-8462
    Keywords: magnetic field ; ion motion ; resonance properties ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: To analyze the mechanisms of action of weak electric and magnetic fields on ion motion in solution, a new approach is outlined allowing for collective interactions of large ionic ensembles with the external field. Bioelectromagnetics 18:25-27, 1997. © 1997 Wiley-Liss, Inc.
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    Electrochemical treatment of lung cancer (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 8-13 
    Details
    ISSN: 0197-8462
    Keywords: lung neoplasm ; tumor regression ; survival rate ; direct current ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A pilot study of electrochemical treatment (ECT) as a therapy for 386 patients with nonsmall cell lung cancer was undertaken. There were 103 stage II cases, 89 stage IIIa cases, 122 stage IIIb cases, and 72 stage IV cases. Two ECT methods were used: For peripherally located lung cancer, platinum electrodes were inserted transcutaneously into the tumor under x-ray or CT guidance. For central type lung cancer or for those inoperable during thoracotomy, electrodes were inserted intraoperatively directly into the cancer. Voltage was 6-8 V, current was 40-100 mA, and electric charge was 100 coulombs per cm of tumor diameter. The number of electrodes was determined from the size of cancer mass, because the diameter of effective area around each electrode is approximately 3 cm. The short-term (6 months after ECT) results of the 386 lung cancer cases were: complete response (CR), 25.6% (99/386); partial response (PR), 46.4% (179/386); no change (NC), 15.3% (59/386); and progressive disease (PD), 12.7% (49/386). The total effective rate (CR + PR) was 72% (278/386). The 1, 3, and 5 year overall survival rates were 86.3% (333/386), 58.8% (227/386), and 29.5% (114/386), respectively. The main complication was traumatic pneumothorax, with an incidence rate of 14.8% (57/386). These clinical results show that ECT is simple, safe, effective, and minimally traumatic. ECT provides an alternative method for treating lung cancers that are conventionally inoperable, that are not responsive to chemotherapy or radiotherapy, or that cannot be resected after thoracotomy. Long-term survival rates suggest that ECT warrants further investigation. Bioelectromagnetics 18:8-13, 1997. © 1997 Wiley-Liss, Inc.
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    Electrochemical treatment of mouse and rat fibrosarcomas with direct current (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 14-24 
    Details
    ISSN: 0197-8462
    Keywords: tumor ; fibrosarcoma ; electrochemistry ; tumor regression ; direct current ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Electrochemical treatment (ECT) of cancer utilizes direct current to produce chemical changes in tumors. ECT has been suggested as an effective alternative local cancer therapy. However, a methodology is not established, and mechanisms are not well studied. In vivo studies were conducted to evaluate the effectiveness of ECT on animal tumor models. Radiation-induced fibrosarcomas were implanted subcutaneously in 157 female C3H/HeJ mice. Larger rat fibrosarcomas were implanted on 34 female Fisher 344 rats. When the spheroidal tumors reached 10 mm in the mice, two to five platinum electrodes were inserted into the tumors at various spacings and orientations. Ten rats in a pilot group were treated when their ellipsoidal tumors were about 25 mm long; electrode insertion was similar to the later part of the mouse study, i.e., two at the base and two at the center. A second group of 24 rats was treated with six or seven electrodes when their tumors were about 20 mm long; all electrodes were inserted at the tumor base. Of the 24 rats, 12 of these were treated once, 10 were treated twice, and 2 were treated thrice. All treated tumors showed necrosis and regression for both mice and rats; however, later tumor recurrence reduced long-term survival. When multiple treatments were implemented, the best 3 month mouse tumor cure rate was 59.3%, and the best 6 month rat tumor cure rate was 75.0%. These preliminary results indicate that ECT is effective on the radiation-induced fibrosarcoma (RIF-1) mouse tumor and rat fibrosarcoma. The effectiveness is dependent on electrode placement and dosage. Bioelectromagnetics 18:14-24, 1997. © 1997 Wiley-Liss, Inc.
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    Amyotrophic lateral sclerosis and occupational exposure to electromagnetic fields (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 28-35 
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    ISSN: 0197-8462
    Keywords: extremely low frequency ; case-control study ; neurodegenerative disease ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: In an hypothesis-generating case-control study of amyotrophic lateral sclerosis, lifetime occupational histories were obtained. The patients (n = 28) were clinic based. The occupational exposure of interest in this report is electromagnetic fields (EMFs). This is the first and so far the only exposure analyzed in this study. Occupational exposure up to 2 years prior to estimated disease symptom onset was used for construction of exposure indices for cases. Controls (n = 32) were blood and nonblood relatives of cases. Occupational exposure for controls was through the same age as exposure for the corresponding cases. Twenty (71%) cases and 28 (88%) controls had at least 20 years of work experience covering the exposure period. The occupational history and task data were used to classify blindly each occupation for each subject as having high, medium/high, medium, medium/low, or low EMF exposure, based primarily on data from an earlier and unrelated study designed to obtain occupational EMF exposure information on workers in “electrical” and “nonelectrical” jobs. By using the length of time each subject spent in each occupation through the exposure period, two indices of exposure were constructed: total occupational exposure (E1) and average occupational exposure (E2). For cases and controls with at least 20 years of work experience, the odds ratio (OR) for exposure at the 75th percentile of the E1 case exposure data relative to minimum exposure was 7.5 (P 〈 0.02; 95% Cl, 1.4-38.1) and the corresponding OR for E2 was 5.5 (P 〈 0.02; 95% CI, 1.3-22.5). For all cases and controls, the ORs were 2.5 (P 〈 0.1; 95% CI, 0.9-8.1) for E1 and 2.3 (P = 0.12; 95% CI, 0.8-6.6) for E2. This study should be considered an hypothesis-generating study. Larger studies, using incident cases and improved exposure assessment, should be undertaken. Bioelectromagnetics 18:28-35, 1997. © 1997 Wiley-Liss, Inc.
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    Histological changes during development of the cerebellum in the chick embryo exposed to a static magnetic field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 36-46 
    Details
    ISSN: 0197-8462
    Keywords: cell migration ; cell differentiation ; cerebellar cortex ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Few studies have been performed to evaluate the ultrastructural changes that exposure to static magnetic fields (SMF) can cause to the processes of cell migration and differentiation in the cerebellum during development. Thus, we have studied the development of the cerebellum in the chick embryo (n = 144) under a uniform SMF (20 mT). All of our observations were done on folium VIc of Larsell's classification. The cerebella of chick embryos, which were exposed solely on day 6 of incubation and sacrificed at day 13 of incubation [short exposure (S)1; n = 24], showed an external granular layer (EGL) that was less dense than the EGL in the control group (n = 24). The molecular layer (ML) exhibited a low number of migratory neuroblastic elements. Moreover, the internal granular layer (IGL) was immature, with the cellular elements less abundant and more dispersed than in controls. In chick embryos exposed on day 6 of incubation and sacrificed at day 17 (S2; n = 24), the outstanding feature was the regeneration of the different layers of the cerebellar cortex. The cerebellar cortex of chick embryos exposed continuously to an identical field from the beginning of the incubation up to day 13 [long exposure (L)1; n = 24] or day 17 (L2; n = 24) of incubation showed a higher number of alterations than that of group S1. Electron microscopy confirmed the findings from light microscopy and, at the same time, showed clear signs of cell degeneration and delay in the process of neuronal differentiation. This was more apparent in groups L1 (100%) and L2 (100%) than in groups S1 (95.4%) and S2 (65.2%). In conclusion, the present study showed that SMF can induce irreversible developmental effects on the processes of cell migration and differentiation of the chick cerebellar cortex. Bioelectromagnetics 18:36-46, 1997. © 1997 Wiley-Liss, Inc.
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    Exposure of children to residential magnetic fields in Norway: Is proximity to power lines an adequate predictor of exposure? (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 47-57 
    Details
    ISSN: 0197-8462
    Keywords: transmission line ; exposure calculations ; home appliances ; school exposure ; epidemiology ; exposure surrogates ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The aim of this work was to study the exposure to magnetic fields of children living at different distances from a power line and to evaluate how well theoretical calculations compared with actual exposure. Personal exposure instruments were carried for 24 h by 65 schoolchildren living 28-325 m from a 300 kV transmission line; the current load was 200-700 A. About half of the children attended a school far from the power line, whereas the other half attended a school located about 25 m from the line. Exposure to magnetic fields was analyzed for three categories of location: at home, at school, and at all other places. Time spent in bed was analyzed separately. The results indicated that children who lived close to a power line had a higher magnetic field exposure than other children. The power line was the most important source of exposure when the magnetic field due to the line was greater than about 0.2 μT. Exposure at school influenced the 24 h time-weighted average results considerably in those cases where the distance between home and power line was very different from the distance between school and power line. The calculated magnetic field, based on line configuration, current load, and distance between home and power line, corresponded reasonably well with the measured field. However, the correlation depends on whether home only or 24 h exposure is used in the analysis and on which school the children attended. The calculated magnetic field seems to be a reasonably good predictor of actual exposure and could be used in epidemiological studies, at least in Norway, where the electrical system normally results in less ground current than in most other countries. Bioelectromagnetics 18:47-57, 1997. © 1997 Wiley-Liss, Inc.
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    Static uniform magnetic fields and amoebae (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 81-84 
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    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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    Comparison of cardiac and 60 Hz magnetically induced electric fields measured in anesthetized rats (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 317-323 
    Details
    ISSN: 0197-8462
    Keywords: ELF magnetic fields ; dosimetry ; electrocardiogram ; endogenous fields ; in vivo fields ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Extremely low frequency magnetic fields interact with an animal by inducing internal electric fields, which are in addition to the normal endogenous fields present in living animals. Male rats weighing about 560 g each were anesthetized with ketamine and xylazine. Small incisions were made in the ventral body wall at the chest and upper abdomen to position a miniature probe for measuring internal electric fields. The calibration constant for the probe size was 5.7 mm, with a flat response from at least 12 Hz to 20 kHz. A cardiac signal, similar to the normal electrocardiogram with a heart rate of about 250 bpm, was readily obtained at the chest. Upon analysis of its spectrum, the cardiac field detected by the probe had a broad maximum at 32-95 Hz. When the rats were exposed to a 1 mT, 60 Hz magnetic field, a spike appeared in the spectrum at 60 Hz. The peak-to-peak magnitudes of electric fields associated with normal heart function were comparable to fields induced by a 1 mT magnetic field at 60 Hz for those positions measured on the body surface (where induced fields were maximal). Within the body, or in different directions relative to the applied field, the induced fields were reduced (reaching zero at the center of the animal). The cardiac field increased near the heart, becoming much larger than the induced field. Thus, the cardiac electric field, together with the other endogenous fields, combine with induced electric fields and help to provide reference levels for the induced-field dosimetry of ELF magnetic field exposures of living animals. Bioelectromagnetics 18:317-323, 1997. © 1997 Wiley-Liss, Inc.
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    Search for frequency-specific effects of millimeter-wave radiation on isolated nerve function (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 324-334 
    Details
    ISSN: 0197-8462
    Keywords: nerve conduction ; compound action potential ; frequency-specific bioeffects ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Effects of a short-term exposure to millimeter waves (CW, 40-52 GHz, 0.24-3.0 mW/cm2) on the compound action potential (CAP) conduction were studied in an isolated frog sciatic nerve preparation. CAPs were evoked by either a low-rate or a high-rate electrical stimulation of the nerve (4 and 20 paired pulses/s, respectively). The low-rate stimulation did not alter the functional state of the nerve, and the amplitude, latency, and peak latency of CAPs could stay virtually stable for hours. Microwave irradiation for 10-60 min at 0.24-1.5 mW/cm2, either at various constant frequencies or with a stepwise frequency change (0.1 or 0.01 GHz/min), did not cause any detectable changes in CAP conduction or nerve refractoriness. The effect observed under irradiation at a higher field intensity of 2-3 mW/cm2 was a subtle and transient reduction of CAP latency and peak latency along with a rise of the test CAP amplitude. These changes could be evoked by any tested frequency of the radiation; they reversed shortly after cessation of exposure and were both qualitatively and quantitatively similar to the effect of conventional heating of 0.3-0.4°C. The high-rate electrical stimulation caused gradual and reversible decrease of the amplitude of conditioning and test CAPs and increased their latencies and peak latencies. These changes were essentially the same with and without irradiation (2.0-2.7 or 0.24-0.28 mW/cm2), except for attenuation of the decrease of the test CAP amplitude. This effect was observed at both field intensities, but was statistically significant only for certain frequencies of the radiation. Within the studied limits, this effect appeared to be dependent on the frequency rather than on the intensity of the radiation, but this observation requires additional experimental confirmation. Bioelectromagnetics 18:324-334, 1997. © 1997 Wiley-Liss, Inc.
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    Eremenko T, Esposito C, Pasquarelli, Pasquali, Volpe P (1997) Cell-cycle kinetics of friend erythroleukemia cells in a magnetically shielded room and in a low-frequency/low-intensity magnetic field. Bioelectromagnetics 18:58-66 (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 339-339 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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    Interactions of radiofrequency radiation-induced hyperthermia and 2-methoxyethanol teratogenicity in rats (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 349-359 
    Details
    ISSN: 0197-8462
    Keywords: RF radiation ; industrial solvents ; glycol ethers ; developmental toxicity ; synergism ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Radiofrequency (RF) radiation is used in a variety of workplaces. In addition to RF radiation, many workers are concurrently exposed to numerous chemicals; exposed workers include those involved with the microelectronics industry, plastic sealers, and electrosurgical units. The developmental toxicity of RF radiation is associated with the degree and duration of hyperthermia induced by the exposure. Previous animal research indicates that hyperthermia induced by an elevation in ambient temperature can potentiate the toxicity and teratogenicity of some chemical agents. We previously demonstrated that combined exposure to RF radiation (10 MHz) and the industrial solvent, 2-methoxyethanol (2ME), produces enhanced teratogenicity in rats. The purpose of the present research is to determine the effects of varying the degree and duration of hyperthermia induced by RF radiation (sufficient to maintain colonic temperatures at control [38.5], 39.0, 40.0, or 41.0 °C for up to 6 h) and 2ME (100 mg/kg) administered on gestation day 13 of rats. Focusing on characterizing the dose-response pattern of interactions, this research seeks to determine the lowest interactive effect level. Day 20 fetuses were examined for external and skeletal malformations. The results are consistent with previous observations. Significant interactions were observed between 2ME and RF radiation sufficient to maintain colonic temperatures at 41 °C for 1 h, but no consistent interactions were seen at lower temperatures even with longer durations. These data indicate that combined exposure effects should be considered when developing both RF radiation and chemical exposure guidelines and intervention strategies. Bioelectromagnetics 18:349-359, 1997. © 1997 Wiley-Liss, Inc.
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    Effects function analysis of ELF magnetic field exposure in the electric utility work environment (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 365-375 
    Details
    ISSN: 0197-8462
    Keywords: ELF ; EMF ; effects functions ; exposure assessment ; occupational exposure ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The incomplete understanding of the relation between power-frequency fields and biological responses raises problems in defining an appropriate metric for exposure assessment and epidemiological studies. Based on evidence from biological experiments, one can define alternative metrics or effects functions that embody the relationship between field exposure patterns and hypothetical health effects. In this paper, we explore the application of the “effects function” approach to occupational exposure data. Our analysis provides examples of exposure assessments based on a range of plausible effects functions. An EMDEX time series data set of ELF frequency (40-800 Hz) magnetic field exposure measurements for electric utility workers was analyzed with several statistical measures and effects functions: average field strength, combination of threshold and exposure duration, and field strength changes. Results were compared for eight job categories: electrician, substation operator, machinist, welder, plant operator, lineman/splicer, meter reader, and clerical. Average field strength yields a different ranking for these job categories than the ranks obtained using other biologically plausible effects functions. Whereas the group of electricians has the highest exposure by average field strength, the group of substation operators has the highest ranking for most of the other effects functions. Plant operators rank highest in the total number of field strength changes greater than 1 μT per hour. The clerical group remains at the lowest end for all of these effects functions. Our analysis suggests that, although average field strength could be used as a surrogate of field exposure for simply classifying exposure into “low” and “high,” this summary measure may be misleading in the relative ranking of job categories in which workers are in “high” fields. These results indicate the relevance of metrics other than average field strength in occupational exposure assessment and in the design and analysis of epidemiological studies. Bioelectromagnetics 18:365-375, 1997. © 1997 Wiley-Liss, Inc.
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    Comment on “Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results” by Mark S. Davies (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 400-400 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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    Detection of magnetism in the red imported fire ant (Solenopsis invicta) using magnetic resonance imaging (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 396-399 
    Details
    ISSN: 0197-8462
    Keywords: social insects ; ferromagnetism ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Red imported fire ant (Solenopsis invicta) workers, queens, and alates were analyzed by magnetic resonance imaging (MRI) for the presence of natural magnetism. Images of ants showed distortion patterns similar to those of honey bees and monarch butterflies, both of which possess ferromagnetic material. The bipolar ring patterns of MRI indicated the presence in fire ants of small amounts of internal magnetic material, which may be used in orientation behaviors, as in the honey bees. Bioelectromagnetics 18:396-399, 1997. © 1997 Wiley-Liss, Inc.
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    Reply to Parkinson (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 401-401 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: No abstract.
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    Thresholds of microwave-evoked warmth sensations in human skin (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 403-409 
    Details
    ISSN: 0197-8462
    Keywords: warmth threshold ; psychophysics ; infrared ; microwaves ; skin sensation ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: We measured thresholds for microwave-evoked skin sensations of warmth at frequencies of 2.45, 7.5, 10, 35, and 94 GHz. In the same subjects, thresholds of warmth evoked by infrared radiation (IR) were also measured for comparison. Detection thresholds were measured on the skin in the middle of the back in 15 adult male human subjects at all microwave (MW) frequencies and with IR. Long duration (10-s), large area (327-cm2) stimuli were used to minimize any differential effects of temporal or spatial summation. Sensitivity increased monotonically with frequency throughout the range of microwave frequencies tested. The threshold at 94 GHz (4.5 ± 0.6 mW/cm2) was more than an order of magnitude less than at 2.45 GHz (63.1 ± 6.7 mW/cm2), and it was comparable to the threshold for IR (5.34 ± 1.07 mW/cm2). Bioelectromagnetics 18:403-409, 1997. © 1997 Wiley-Liss, Inc.
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    Mortality of plastic-ware workers exposed to radiofrequencies (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 418-421 
    Details
    ISSN: 0197-8462
    Keywords: non-ionizing radiation ; occupational cancer ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The mortality experience of a cohort of Italian plastic-ware workers exposed to radiofrequency (RF)-electromagnetic fields generated by dielectric heat sealers was investigated. Follow-up extended from 1962 to 1992. The standardised mortality ratio (SMR) analysis was restricted to 481 women workers, representing 78% of the total person-years at risk. Mortality from malignant neoplasms was slightly elevated, and increased risks of leukemia and accidents were detected. The all-cancer SMR was higher among women employed in the sealing department, where exposure to RF occurred, than in the whole cohort. This study raises interest in a possible association between exposure to RF radiation and cancer risk. However, the study power was very small, and the possible confounding effects of exposure to solvents and vinyl chloride monomer (VCM) could not be ruled out. The hypothesis of an increased risk of cancer after radiofrequency exposure should be further explored by means of analytical studies characterised by adequate power and more accurate exposure assessment. Bioelectromagnetics 18:418-421, 1997. © 1997 Wiley-Liss, Inc.
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    Increased resorptions in CBA mice exposed to low-frequency magnetic fields: An attempt to replicate earlier observations (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 410-417 
    Details
    ISSN: 0197-8462
    Keywords: reproduction ; ELF ; VLF ; magnetic fields ; replication studies ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This paper has two aims. First, it reports the findings of a study on the effects of low-frequency magnetic fields on reproduction. Second, it serves as an example of an attempt to replicate the results of an experimental study in an independent laboratory and discusses some of the problems of replication studies. To try to replicate the findings of a study reporting increased resorptions (fetal loss) in mice exposed to 20 kHz magnetic fields with sawtooth waveform and to study the possible effects of 50 Hz sinusoidal fields, pregnant mice were exposed to magnetic fields from day 0 to 18 of pregnancy, 24 h per day. The flux densities of the vertical magnetic fields were 15 μT (peak-to-peak) at 20 kHz and 13 or 130 μT (root mean square) at 50 Hz. Two strains of animals were used: CBA/S mice imported from the laboratory reporting the original observations, and a closely related strain CBA/Ca. The CBA/S mice were cleaned of pathogenic microbes and parasites before they were imported into our laboratory. The magnetic field exposures did not affect resorption rate in CBA/Ca mice. In CBA/S, the frequency of resorptions was higher in the exposed mice than in the control group. However, the increase was not significantly different from either the no-effect hypothesis or the results of the original study we were attempting to replicate. Differences between the two studies and difficulties in interpreting the results are discussed. It is concluded that the results tend more to support than argue against increased resorptions in CBA/S mice exposed to the 20 kHz magnetic field. The results demonstrate that animal strain is an important variable in bioelectromagnetics research: even closely related strains may show different responses to magnetic field exposure. Bioelectromagnetics 18:410-417, 1997. © 1997 Wiley-Liss, Inc.
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    Intracellular calcium signaling by jurkat T-lymphocytes exposed to a 60 hz magnetic field (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 439-445 
    Details
    ISSN: 0197-8462
    Keywords: ELF ; magnetic fields ; calcium ; jurkat ; flow-cytometry ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: To explore possible biochemical mechanisms whereby electromagnetic fields of around 0.1 mT might affect immune cells or developing cancer cells, we studied intracellular calcium signaling in the model system Jurkat E6-1 human T-leukemia cells during and following exposure to a 60 Hz magnetic field. Cells were labeled with the intracellular calcium-sensitive fluorescent dye Fluo-3, stimulated with a monoclonal antibody against the cell surface structure CD3 (associated with ligand-stimulated T-cell activation), and analyzed on a FACScan flow-cytometer for increases in intensity of emissions in the range of 515-545 nm. Cells were exposed during or before calcium signal-stimulation to 0.15 mTrms 60 Hz magnetic field. The total DC magnetic field of 78.2 μT was aligned 17.5° off the vertical axis. Experiments used both cells cultured at optimal conditions at 37 °C and cells grown under suboptimal conditions of 24 °C, lowered external calcium, or lowered anti-CD3 concentration. These experiments demonstrate that intracellular signaling in Jurkat E6-1 was not affected by a 60 Hz magnetic field when culture and calcium signal-stimulation were optimal or suboptimal. These results do not exclude field-induced calcium-related effects further down the calcium signaling pathway, such as on calmodulin or other calcium-sensitive enzymes. Bioelectromagnetics 18:439-445, 1997. © 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
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    RF radiation-induced changes in the prenatal development of mice (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 18 (1997), S. 455-461 
    Details
    ISSN: 0197-8462
    Keywords: RF radiation effects ; prenatal development ; mice development ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The possible effects of radiofrequency (RF) radiation on prenatal development has been investigated in mice. This study consisted of RF level measurements and in vivo experiments at several places around an “antenna park.” At these locations RF power densities between 168 nW/cm2 and 1053 nW/cm2 were measured. Twelve pairs of mice, divided in two groups, were placed in locations of different power densities and were repeatedly mated five times. One hundred eighteen newborns were collected. They were measured, weighed, and examined macro- and microscopically. A progressive decrease in the number of newborns per dam was observed, which ended in irreversible infertility. The prenatal development of the newborns, however, evaluated by the crown-rump length, the body weight, and the number of the lumbar, sacral, and coccygeal vertebrae, was improved. Bioelectromagnetics 18:455-461, 1997. © 1997 Wiley-Liss, Inc.
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