bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of 60‐Hz electric fields on specific humoral and cellular components of the immune system
Authors: Morris J. E. , Phillips R. D.
Published: February 2006

We evaluated humoral and cellular functions of the immune system of Swiss‐Webster mice exposed to 60‐Hz electric fields at 100 kV/m. No significant differences were observed in primary antibody response to keyhole limpet hemocyanin (precipitating antibody levels) between exposed (30 or 60 days) and control mice, nor were there significant changes in mitogen‐stimulation response of spleen cells from mice similarly exposed for 90 or 150 days when compared to sham‐exposed animals.
Possible effects of 1011 Hz radiation on the oxygen affinity of hemoglobin
Authors: Kondepudi D. K.
Published: February 2006

When oxygen binds to one of the subunits of hemoglobin, the oxygen affinity of the other subunits is enhanced. This cooperative interaction of the subunits is initiated by the movement of the heme plane toward the proximal side when oxygen binds to the heme. This motion is transmitted to the surface of the globin through a “reaction channel” consisting of a group of atoms whose motion is well correlated. Considering the detailed geometry and X‐ray diffraction data of the mean square displacement of the atoms surrounding the heme, a simple model for the heme plane oscillations is developed. Using this model, the natural frequency of oscillations is shown to be ≈5 × 1011 Hz. This result, along with the recent experimental data on the kinetics of the conformational changes of the heme, points to the possibility of radiation influencing the oxygen affinity of hemoglobin. If such an effect exists, it is likely that the oxygen affinity will be enhanced by the radiation.
Local tumor hyperthermia using a computer‐controlled microwave system
Authors: Magin R. L. , Fu T. S. , Beard R. E. , Cain C. A.
Published: February 2006

A minicomputer‐based system was designed to control the microwave (2.45‐GHz) power to four local hyperthermia applicators. Errors in temperature measurement, due to electromagnetic field interactions with small thermocouple probes, are minimized by sampling the temperature only when the microwave power is off. The programmable controller can regulate the temperature in tumors in 0.1 °C increments from 30 to 60 °C. This technique reduces temperature differences throughout the tumor at steady state to less than 0.4 °C and prevents skin burns.
Systems for exposing mice to 2,450‐MHz electromagnetic fields
Authors: Chou Chung‐Kwang , Guy Arthur W.
Published: February 2006

Two systems for exposing mice to 2,450‐MHz electromagnetic fields are described. In a waveguide system, four mice were placed in a Styrofoam cage and exposed dorsally to circularly polarized electromagnetic fields. The temperature and humidity in the mouse holder were kept constant by forced‐air ventilation. For 1‐W input power to the waveguide, the average specific absorption rate (SAR) was determined by twin‐well calorimetry to be 3.60 ± 0.11 (SE) W/kg in 27‐g mice. The maximum SAR at the skin surface determined thermographically was 8.36 W/kg in the head of the mouse. The second system was a miniature anechoic chamber. Six mice were irradiated dorsally to far field plane waves. Copper shielding and high‐temperature absorbing material were lined inside the chamber to accommodate the high input power. The air ventilation at the location of the mice was separately controlled so that any heating in the absorber would not affect the animals. For 1‐W input power, the average SAR was 0.17 ± 0.01 W/kg and the maximum SAR at the skin surface was 0.41 W/kg in the animal when irradiated with body axis parallel to the E field; the SARs were 0.11 ± 0.01 W/kg and 0.64 W/kg, respectively, when irradiated perpendicular to the E field.
In vivo and in vitro dielectric properties of animal tissues at radio frequencies
Authors: Kraszewski Andrzej , Stuchly Maria A. , Stuchly Stanislaw S. , Smith Andrew M.
Published: February 2006

An open‐ended coaxial line and an improved measurement method employing a computer controlled network analyzer were used to measure the permittivity of cat tissues. Muscle, spleen, kidney cortex, liver,and brain cortex were measured in vivo and in vitro at frequencies between 100 MHz and 8 GHz. The differences between the permittivities of these cat tissues, in the aforementioned range of frequencies, when measured in vivo and a few (up to four) hours after death, were found to be within the experimental uncertainty.
A behavioral response of swine to a 60‐Hz electric field
Authors: Hjeresen D. L. , Miller M. C. , Kaune W. T. , Phillips R. D.
Published: February 2006

It has been shown that rats, given the choice, will spend more time out of a 60‐Hz electric field than in it at field strengths ⩾ 75 kV/m. This paper describes research to examine the relevance of these data to a different species, the pig. Miniature pigs that had been exposed to a 60‐Hz electric field at 30 kV/m for 20 h/day, 7 days/week for as long as 6 months, were tested for their preference for the presence or absence of the field during a 23.5‐h period. Similar to earlier results with rats, miniature pigs spent more time out of the electric field than in it during the sleeping period.
Effects of X‐band microwave exposure on rabbit erythrocytes
Authors: Cleary S. F. , Garber F. , Liu L. M.
Published: February 2006

Rabbit erythrocytes were exposed in vitro to continuous wave (CW) and pulse‐modulated X‐band microwaves in wave guide exposure chambers. Erythrocytes were exposed as whole (hep‐arinized) blood suspensions or as washed cells in 1:1 isotonic buffered K+‐free saline suspensions. Statistically significant increases in K+ efflux relative to thermal controls were detected when red cells were exposed in whole blood suspensions to either CW or pulsed 8.42‐GHz microwaves at SARs that resulted in equilibrium sample temperatures of approximately 24 °C. Under the same exposure conditions, no statistically significant K+ efflux occurred in the case of 1:1 red cell suspensions. Measured differences in sample heating rates and temperature gradients between microwave‐exposed and heated control suspensions may account in part for the differential effect of microwave exposure but such effects do not appear to explain the results of this study fully.
Attempts to alter 45Ca2+ binding to brain tissue with pulse‐modulated microwave energy
Authors: Merritt James H. , Chamness Albert F. , Shelton Wesley W.
Published: February 2006

Rat brain tissue, loaded with 45Ca2+ by intraventricular injection was exposed in vitro to pulsemodulated 1‐GHz (SAR of 0.29 or 2.9 W/kg) or 2.45‐GHz radiation (SAR = 0.3 W/kg), and in vivo to 2.06‐GHz radiation (SAR of 0.12 to 2.4 W/kg). There were no significant differences in efflux of 45Ca2+ between the microwave‐ and sham‐irradiated groups.
Minimal changes in hypothalamic temperature accompany microwave‐induced alteration of thermoregulatory behavior
Authors: Adair Eleanor R. , Adams Barbara W. , Akel Gillian M.
Published: February 2006

This study probed the mechanisms underlying microwave‐induced alterations of thermoregulatory behavior. Adult male squirrel monkeys (Saimiri sciureus), trained to regulate the temperature of their immediate environment (Ta) behaviorally, were chronically implanted with Teflon reentrant tubes in the medical preoptic/anterior hypothalamic area (PO/AH), the brainstem region considered to control normal thermoregulatory processes. A Vitek temperature probe inserted into the tube measured PO/AH temperature continuously while changes in thermoregulatory behavior were induced by either brief (10‐min) or prolonged (2.5‐h) unilateral exposures to planewave 2,450‐MHz continuous wave (CW) microwaves (E polarization). Power densities explored ranged from 4 to 20 mW/cm2 (rate of energy absorption [SAR] = 0.05 [W/kg]/[mW/cm2]). Rectal temperature and four representative skin temperatures were also monitored, as was the Ta selected by the animal. When the power density was high enough to induce a monkey to select a cooler Ta (8 mW/cm2 and above), PO/AH temperature rose ∼ 0.3°C but seldom more. Lower power densities usually produced smaller increases in PO/AH temperature and no reliable change in thermoregulatory behavior. Rectal temperature remained constant while PO/AH temperature rose only 0.2–0.3°C during 2.5‐h exposures at 20 mW/cm2 because the Ta selected was 2–3°C cooler than normally preferred. Sometimes PO/AH temperature increments greater than 0.3°C were recorded, but they always accompanied inadequate thermoregulatory behavior. Thus, a PO/AH temperature rise of 0.2–0.3°C, accompanying microwave exposure, appears to be necessary and sufficient to alter thermoregulatory behavior, which ensures in turn that no greater temperature excursions occur in this hypothalamic thermoregulatory center.
Offset of the vacuolar potential of Characean cells in response to electromagnetic radiation over the range 250 Hz‐250 kHz
Authors: Montaigne Kathleen , Pickard William F.
Published: February 2006

Measurements were made of the small, transient offsets of vacuolar potential produced in single cells of Nitella flexilis and Chara braunii by isolated bursts of audio frequency electromagnetic radiation. The offsets increased in magnitude with decreasing frequency of the electromagnetic radiation and, below about 6 kHz, seemed to approach a lowfrequency asymptote. This frequency dependence for the offset is shown to be in accordance with a previously developed model in which the incident radiation is weakly rectified by the cell's membrane system.
In vitro effects of microwave radiation on rat liver mitochondria
Authors: Dutton M. Susan , Galvin Michael J. , McRee D. I.
Published: February 2006

Liver mitochondria were exposed in vitro at 30°C to microwave radiation (2.45 GHz) during the following states of respiraton: resting, state 1; substrate dependent, state 2; ADP stimulated, state 3; and ADP depleted, state 4. At 10 or 100 mW/g, with succinate as substrate, no effect of exposure was observed on states 1–4 or the respiratory control index (state 3/state 4) of either tightly or loosely coupled mitochondria. When glutamate was used as substrate, no effects were observed at 10 mW/g. However, in the loosely coupled mitochondria the 100 mW/g exposure produced an increase in states 2 and 4 and a decrease in the respiratory control index. The results suggest that the function of loosely coupled mitochondria can be affected at high power levels of microwave radiation.
Theoretical and experimental determination of SAR patterns for spherical tissue models in a rectangular resonant cavity
Authors: Yang Gen‐Yuan , Chou Chung‐Kwang , Guy Arthur W.
Published: February 2006

Specific absorption rates (SARs) were determined theoretically and experimentally for several spherical models of tissue exposed to electrical fields of TE101 mode in a rectangular cavity of 57.3 MHz resonant frequency. The approximate theoretical SAR can be calculated according to the Mie theory by superposition of four plane waves representing the fields excited in the cavity. The theoretical and thermographically determined SAR patterns in spheres with radii of 5, 7.5, and 10 cm and with conductivities of 0.1, 1, and 10 S/m were compared. For a sphere with radius less than 7.5 cm and conductivity less than 1 S/m, the SAR was quite uniform. When conductivity was increased to 10 S/m, the SAR patterns showed higher absorption in the periphery of the largest sphere (10‐cm radius). These characteristics are important in evaluating the scaling technique of exposing a model of a human to very‐high‐frequency fields to obtain power absorption data in humans exposed to high‐frequency or very‐low‐frequency fields.
The effect of frequency and grounding on whole‐body absorption of humans in E‐polarized radiofrequency fields
Authors: Hill Douglas A.
Published: February 2006

The radiofrequency absorption rates of five male human volunteers have been measured from 3 to 41 MHz. The subjects were exposed at about 10 μW/cm2 inside a very large transverse electromagnetic (TEM) cell and never absorbed more than 1 W. Both the EKH and EHK orientations were employed under both free‐space and grounded conditions. Absorption rates for the EKH orientation exceed those of the EHK orientation by 40% in free space, but only by 6% when grounded. The absorption rates for the grounded men vary with frequency, f, as f1.9 from 3 to 25 MHz and then level off at the peak. The freespace absorption rates vary as f1.7 from 3 to 18 MHz and as f2.9 from 18 to 41 MHz. The average measured absorption rates at 10 MHz exceed the average of the standard model calculations by a factor of three (for free space) or four (grounded). The average man, when exposed grounded in an EKH orientation to the maximum permitted exposure levels under ANSI standard C95.1‐1982, will absorb 0.58 ± 0.14 W/kg over most of the 3 to 41‐MHz frequency range. This slightly exceeds the whole‐body maximum of 0.40 W/kg underlying the standard.
A reference curve for axial bioelectric potentials in rabbit tibia
Authors: Rubinacci A. , Brigatti L. , Tessari L.
Published: February 2006

A high coefficient of variation is characteristic of the bioelectric potentials recorded from living long bones. As a consequence, the data collected from animal and human experiments are difficult to use in practical ways. A distribution curve for bone bioelectric potentials has been calculated using polynomial regression analysis to process the voltage values recorded on the whole length of rabbit tibiae, with reference electrodes positioned in three different points of the bone. The distribution curve so obtained is presented to fulfill the need for a reference curve for the bioelectric potentials recorded from rabbit tibial surfaces.
Ethanol‐induced hypothermia and ethanol consumption in the rat are affected by low‐level microwave irradiation
Authors: Lai H. , Horita A. , Chou C. K. , Guy A. W.
Published: February 2006

Microwave irradiation of rats by circularly polarized, 2,450‐MHz, pulsed waves (2‐μs pulses; 500 pps) was performed in waveguides to determine effects on ethanol‐induced hypothermia and on ethanol consumption. Rats injected intraperitoneally with ethanol (3 g/kg in a 25% v/v water solution) immediately after 45 min of microwave irradiation exhibited attenuation of the initial rate of fall in body temperature, which was elicited by the ethanol, but exhibited no significant difference in maximal hypothermia as compared with that of sham‐irradiated rats. Microwave irradiation did not affect the consumption of a 10% sucrose (w/v) solution by water‐deprived rats. However, it enhanced the consumption of a solution of 10% sucrose (w/v) + 15% ethanol (v/v) by water‐deprived animals. These results were obtained at a specific absorption rate (SAR) of 0.6 W/kg, which rate of energy dosing would require a power density of 3–6 mW/cm2 if exposure of the animals had occurred to a 12‐cm plane wave.
Thermal action of 2.45 GHz microwaves on the cytoplasm of Chinese hamster cells
Authors: Dardalhon M. , Moré C. , Averbeck D. , Berteaud A. J.
Published: February 2006

In order to demonstrate possible specific effects of microwaves at the cellular level V‐79 Chinese hamster cells were exposed to 2.45‐GHz radiation at power levels of 20–200 mW/cm2 and at specific absorption rates of 10–100 mW/g. Intracellular cytoplasmic changes were observed by fluorescence polarization using a method based on the intracellular enzymatic hydrolysis of nonfluorescent fluorescein diacetate (FDA). At levels of absorbed energy below 90 J/g, modifications of microviscosity and mitochondrial state were absent, but a slight stimulation of enzymatic hydrolysis of FDA was observed which may be explained by microwave‐induced alterations of cellular membranes possibly due to differences in heating pattern of microwaves compared to water‐bath heating. At levels of absorbed energy above 90 J/g, the decrease of enzymatic hydrolysis of FDA, increase in degree of polarization, and increase of permeation of the fluorescent marker correlated well with the decrease in cell viability as measured by the exclusion of trypan blue. At equal absorbed energy, microwaves were found to exert effects comparable to classical heating except that permeation was slightly more affected by microwave than by classical heating. This suggests that membrane alteration produced by microwaves might differ from those induced by classical heating or that microwaves may have heated the membrane to higher temperatures than did classical heating.
Effect of microwave radiation on the beating rate of isolated frog hearts
Authors: Yee K. C. , Chou C. K. , Guy A. W.
Published: February 2006

One hundred and two isolated frog hearts were divided into ten groups and placed individually in a waveguide filled with Ringer's solution and exposed to 2,450‐MHz CW radiation at 2 and 8.55 W/kg. Heart rate was recorded using one of the following methods: 3‐M KCl glass electrode, ultrasound probe, tension transducer, Ringer's solution glass electrode, and a metal wire inserted in the Ringer's solution electrode. An accelerated decrease of heart rate was observed only in those groups recorded using the 3‐M KCl electrode and the metal wire Ringer's solution electrode. No effect was found in the other groups. These results indicate that bradycardia in isolated hearts could be caused by electrode artifacts resulting from the intensification of electromagnetic fields.
Attempts to produce taste‐aversion learning in rats exposed to 60‐Hz electric fields
Authors: Creim J. A. , Lovely R. H. , Kaune W. T. , Phillips R. D.
Published: February 2006

A measure of taste‐aversion (TA) learning was used in three experiments to 1) determine whether exposure to intense 60‐Hz electric fields can produce TA learning in male Sprague‐Dawley rats, and 2) establish a dose‐response function for the behavior in question. In Experiment 1, four groups of eight rats each were distributed into one of two exposures (69 ± 5 kV/m or 133 ± 10 kV/m) or into one of two sham‐exposure groups. Conditioning trials paired 0.1% sodium saccharin in water with 3 h of exposure to a 60‐Hz electric field. Following five conditioning trials, a 20‐min, two‐bottle preference test between water and saccharin‐flavored water failed to reveal TA conditioning in exposed groups. In Experiment 2, four groups of eight rats each (34 ± 2 kV/m or 133 ± 10 kV/m and two sham‐exposed groups) were treated as before. Electric‐field exposure had no effect on TA learning. Experiment 3 tested for a possible synergy between a minimal dose (for TA learning) of cyclophosphamide (6 mg/kg) and 5 h of exposure to 133 ± 10 kV/m electric fields in a dark environment under conditions otherwise similar to those of Experiments 1 and 2. The results indicated no TA learning as reflected in the relative consumption of saccharin.
Internal field strength measurements in chick forebrains at 50, 147, and 450 MHz.
Authors: Weil Claude M. , Spiegel Ronald J. , Joines William T.
Published: February 2006

This report describes some experimental measurements of the internal field levels induced within isolated chick‐forebrains irradiated at 50, 147, and 450 MHz, under essentially the same conditions as those used in the in vitro calcium‐ion efflux experiments. Ratios of incident power at 50/147 MHz and 147/450 MHz that are needed to establish the same probe output are given and comparisons made with values predicted by different spherical models. Data predicted by the layered‐sphere model were found to be in close agreement with measured values for the 50/147‐MHz ratio. Agreement for the 147/450‐MHz ratio was poorer.
Biological effects of a 765‐kV, 60‐Hz transmission line on honey bees (Apis mellifera L.): Hemolymph as a possible stress indicator
Authors: Bindokas Vytautas , Greenberg Bernard
Published: February 2006

Number of circulating hemocytes and hemolymph protein patterns of adult worker honey bees were analyzed as possible indicators of stress resulting from colony placement under a 765‐kV transmission line. Although exposure to 55, 80, and 95 μA total induced hive current (THC) produced colony behavioral disturbance, there were no consistent effects on mean hemocyte counts at 55‐ or 95‐μA THC. Age‐dependent declines in circulating hemocyte number were similar in all exposure groups. There were no consistent differences in tube‐gel electropherograms. No consistent differences were found in two‐density slab‐gel electropherograms based on ultrasensitive silver stain. The 67 positively charged and four negatively charged protein fractions from overwintering bees are two‐ to threefold more than currently reported in the literature.
In utero exposure to microwave radiation and rat brain development
Authors: Merritt J. H. , Hardy K. A. , Chamness A. F.
Published: February 2006

Timed‐pregnancy rats were exposed in a circular waveguide system starting on day 2 of gestation. The system operated at 2,450 MHz (pulsed waves; 8 μs PW; 830 pps). Specific absorption rate (SAR) was maintained at 0.4 W/kg by increasing the input power as the animals grew in size. On day 18 of gestation the dams were removed from the waveguide cages and euthanized; the fetuses were removed and weighed. Fetal brains were excised and weighed, and brain RNA, DNA and protein were determined. Values for measured parameters of the radiated fetuses did not differ significantly from those of sham‐exposed fetuses. A regression of brain weight on body weight showed no micrencephalous fetuses in the radiation group when using as a criterion a regression line based on two standard errors of the estimate of the sham‐exposed group. In addition, metrics derived from brain DNA (ie, cell number and cell size) showed no significant differences when radiation was compared to sham exposure. We conclude that 2,450‐MHz microwave radiation, at an SAR of 0.4 W/kg, did not produce significant alterations in brain organogenesis.
Cerebrovascular permeability to 86Rb in the rat after exposure to pulsed microwaves
Authors: Goldman Harold , Lin James C. , Murphy Sharon , Lin Mei F.
Published: February 2006

Microwaves (pulsed, 2,450 MHz) at an average power density of 3 W/cm2 were applied directly to the head for 5, 10, or 20 min, producing a peak specific absorption rate of 240 W/kg in the brain, which, after a 10‐min exposure, resulted in brain temperatures in excess of 43°C. A bolus of 86Rb in isotonic saline was injected intravenously and an arterial sample was collected for 20 s to determine cardiac output. Compared with unexposed controls, uptake of 86Rb increased most in those regions directly in the path of the irradiation, namely, the occipital and parietal cortex, as well as the dorsal hippocampus, midbrain, and basal ganglia. In a separate group of animals, regional brain‐vascular spaces were found to increase with brain temperature. These results support previous observations indicating that reliably demonstrable increases of blood‐brain barrier permeability are associated with intense, microwave‐induced hyperthermia, and that the observed changes are not due to field‐specific interaction.
Alterations in protein kinase activity following exposure of cultured human lymphocytes to modulated microwave fields
Authors: Byus Craig V. , Lundak Robert L. , Fletche Ramona M. , Adey W. Ross
Published: February 2006

Cultures of human tonsil lymphocytes were exposed in a Crawford cell to a 450‐MHz field (peak envelope intensity 1.0 mW/cm2), sinusoidally amplitude modulated (depth 80%) at frequencies between 3 and 100 Hz for periods up to 60 min. The Crawford cell was housed in a temperature‐controlled chamber (35°C) and control cultures were placed in the same chamber. Activity of cAMP‐dependent protein kinase relative to controls remained unaltered by fields modulated at 16 or 60 Hz with exposures of 15, 30, and 60 min. By contrast, total non‐cAMP‐dependent kinase activity fell to less than 50% of unexposed control levels after 15 and 30 min exposures, but, despite continuing field exposure, returned to control or preexposure levels by 45 and 60 min. A smaller reduction (20–25%) also occurred with 60‐Hz modulation and was also restricted to exposure durations of 15 and 30 min. CW 450‐MHz fields were without effect. Reduced enzyme activity occurred with 16‐, 40‐, and 60‐Hz modulation frequencies, but not with 3‐, 6‐, 80‐, or 100‐Hz modulation. The specific identity of this kinase is unknown. This rapid but transient reduction in lymphocyte protein kinase activity restricted to modulation frequencies between 16 and 60 Hz and to less than 30 min exposure is consistent with „windowing”︁ with respect to modulation frequency and exposure duration.
Short‐circuit currents, surface electric fields, and axial current densities for guinea pigs exposed to ELF electric fields.
Authors: Kaune W. T. , Miller M. C.
Published: February 2006

Short‐circuit currents, surface electric fields, and axial current densities were measured in electrically grounded guinea pigs exposed to a uniform, vertical, ELF electric field. These data are 70–110% of corresponding values obtained in grounded rats exposed to the same electric field.
The relationship between flash evoked potentials and evoked amplitude modulation patterns of an applied UHF electromagnetic field in the rat
Authors: Kelley James T. , Everett Robert , Reilly Edward L. , Colton Glenn S.
Published: February 2006

Pilot studies demonstrate evidence that the electrophysiological processes associated with flash stimulation of the central nervous system (CNS) of rats, as seen in the recordings of visual‐evoked potentials, may also be detectable using an ultrahigh frequency electromagnetic field (UHFEMF). Patterns of amplitude modulation of an applied UHFEMF, when recorded and averaged, show strong correlations with simultaneously recorded evoked potentials. The data support the hypothesis that the UHFEMF amplitude is altered in a dynamic fashion by the tissue's electrophysiological processes that are involved with the generation of CNS electric fields.
SAR in rats exposed in 2,450‐MHz circularly polarized waveguides
Authors: Chou Chung‐Kwang , Guy Arthur W. , Johnson Robert B.
Published: February 2006

Average specific absorption rates (SARs) for live rats exposed in 2,450‐MHz circularly polarized waveguides were estimated from the total system loss determined from measurements using five power meters, and a correction factor representing actual SAR/apparent SAR. The actual SAR was measured by twin‐well calorimetry and the apparent SAR by power meters. Values were obtained for carcasses of various body masses for five orientations. The average SAR with free movement in the cages changed less than threefold as the rats grew from 200 to 700 g. The ratio of peak to average SAR in the body was less than 3. These results indicate relatively constant energy disposition in rats exposed in the circularly polarized waveguide.
Design of a magnetic field generator for experiments on magnetic effects in cell cultures
Authors: Kinouchi Y. , Ushita T. , Sato K. , Miyamoto H. , Yamaguchi H. , Yoshida Y.
Published: February 2006

A magnetic field generator constructed of rare earth‐cobalt magnets is proposed for examining the biological effects of static magnetic fields (less than 1 T) on tissue cultures. Important quantities of a magnetic field from a biological‐effects viewpoint, ie, its strength and the product of strength and gradient, are analysed. A practical procedure for designing the generator with optimum parameters is given. Also, parameters are determined which will yield a sinusoidal spatial field distribution.
Calorimetric measurements of the effect of 330‐MHz radiofrequency radiation on human erythrocyte ghosts
Authors: Shnyrov Valery L. , Zhadan Galina G. , Akoev Inal G.
Published: February 2006

Irreversible changes in the heat capacity of human erythrocyte ghost suspensions due to the effect of 330‐MHz radiofrequency radiation (at a specific absorption rate of approximately 9 mW/g) were detected by the method of scanning differential microcalorimetry. Using the data obtained from the analysis of infrared spectra of air‐dried films of erythrocyte membranes, it can be postulated that the observed microcalorimetric changes are connected with the local interaction of electromagnetic radiation with the channel‐forming portion of band‐3 protein.
The differential effects of 200, 591, and 2,450 MHz radiation on rat brain energy metabolism
Authors: Sanders Aaron P. , Joines William T. , Allis John W.
Published: February 2006

Three key compounds in brain energy metabolism have been measured during and after exposure to continuous wave radiofrequency radiation at 200, 591, and 2,450 MHz. Frequency‐dependent changes have been found for all three compounds. Changes in NADH fluorescence have been measured on the surface of a surgically uncovered rat brain during exposure. At 200 and 591 MHz, NADH fluorescence increased in a dose‐dependent manner between approximately 1 and 10 mW/cm2, then became constant at higher exposures. There was no effect at 2,450 MHz. Levels of ATP and CP were measured in whole brain after exposure. The ATP levels were decreased at 200 and 591 MHz but not at 2,450 MHz. The CP levels decreased only at 591 MHz. The effect of duration of exposure (up to 5 min) was investigated for all compounds at 200 MHz and 2,450 MHz, and exposures to 20 minutes were examined at 591 MHz. Temperature in the rat brain was essentially constant for all exposures. A general mechanism for inhibition of the mitochondrial electron transport chain and the CP‐kinase reaction pathway by radiofrequency radiation has been proposed.
Assessment of the immune responsiveness of mice exposed to a 1.5‐Tesla stationary magnetic field
Authors: Tenforde T. S. , Shifrine M.
Published: February 2006

Humoral and cell‐mediated immune responses were assayed following a 6‐day exposure of LAF1/J mice to a 1.50 Tesla (1 T = 104 Gauss) stationary magnetic field. In tests of the immune response to sheep erythrocytes, the number of Jerne plaques formed by spleen lymphocytes and the level of serum IgM were not significantly different for the exposed mice in comparison with control animals. Tests for mitogen‐induced lymphocyte proliferation also demonstrated no significant differences in the response of spleen lymphocytes from exposed and control groups of mice.
Current densities measured in human models exposed to 60‐Hz electric fields
Authors: Kaune W. T. , Forsythe W. C.
Published: February 2006

This paper gives current densities measured in homogeneous grounded human models exposed to vertical, 60‐Hz electric fields. The methods used for these measurements were validated by measuring the current densities induced in a grounded hemisphere and in a grounded prolate hemispheroid; agreement between measurement and theory was good. For an unperturbed field strength of 10 kV/m, current densities measured in the human chest were in the range 125–300 nA/cm2. A strong horizontal current‐density enhancement was observed in the axillae, with peak values of about 400 nA/cm2. The vertical current density in the arms, when held downward, was in the opposite direction to that in the chest. Current densities in the abdomen, pelvis, and legs were a strong function of whether the body was grounded through one or both feet. With one foot grounded, the horizontal current density in the lower pelvic region, just above the crotch, was 770 nA/cm2. This value was the largest of those measured in the head, arms, or torso of the human model. Scaling factors derived from these data and similar data for animals will provide a quantitative basis for comparing animal and human exposure to 60‐Hz electric fields. In addition, current‐density data given in this paper can be directly extrapolated to higher frequencies, at least to 1 MHz. These extrapolated data may be useful to individuals and groups involved in the determination of safety standards for the lower radiofrequency region.
Further studies of human whole‐body radiofrequency absorption rates
Authors: Hill Douglas A.
Published: February 2006

Further studies of human whole‐body radiofrequency (RF) absorption rates were carried out using a TEM‐cell exposure system. Experiments were done at one frequency near the grounded resonance frequency ( ∼ 40 MHz), and at several below‐resonance frequencies. Absorption rates are small for the K and H orientations of the body, even when grounded. For the body trunk in an E orientation, the absorption rate of a sitting person is about half of the rate for the same person standing with arms at the sides; the latter in turn is about half the rate for the same subject standing with arms over the head. Two‐body interactions cause no increase in absorption rates for grounded people. They do, however, increase the absorption rates for subjects in an E orientation in free space; the largest interaction occurs when one subject is λ/2 behind the other (as seen by the incident wave). When these results are applied to practical occupational exposure situations, the whole‐body specific absorption rate does not exceed the ANSI limit of 0.4 W/kg for exposures permitted by the ANSI standard (C95.1‐1982) at frequencies from 7 to 40 MHz.
Effects of microwave exposure on the hamster immune system. IV. Spleen cell IgM hemolytic plaque formation
Authors: Rao G. V. Rama , Cain C. A. , Tompkins W. A. F.
Published: February 2006

Microwave exposure has been reported to affect various components of the immune system. In this study, we examined the effect of a single whole‐body exposure of hamsters to microwave (mw) energy (2.45 GHz; 5–25 mW/cm2; 1 h) on the IgM antibody (Ab) response of spleen cells to sheep red blood cells (SRBC). MW‐exposed, sham‐exposed, and cage‐control hamsters were immunized with SRBC and plaque‐forming cells (PFC) in spleens assayed using the direct hemolytic plaque assay. In cage‐control hamsters the Ab response was highest between days 4 and 5, returning to baseline by day 9. MW exposure (25 mW/cm2 for 1 h) significantly augmented PFC response only on days 4 and 5 postimmunization, causing approximately a 4.3‐ and 3.5‐fold increase over controls, respectively. Exposure to 15 mW/cm2 caused a lesser, but significant increase in PFC. Exposure to intensities below 15 mW/cm2 for 1 h did not produce any increase in Ab response. Immunization with different concentrations of SRBC following 1 h of 25 mW/cm2 MW exposure revealed a stimulation in PFC at all concentrations ranging from 5 × 107 to 5 × 108 SRBC. Pretreatment of hamsters with MW radiation prior to immunization showed that the animals retained an increased sensitivity to SRBC for as long as 4 days after MW exposure. In contrast, exposure of hamsters to MW energy on different days after immunization showed an effect of the PFC response only if given between 0 and 1 day after immunization. These results suggest that MW exposure augments the primary IgM response to SRBC by affecting some early event in the immune response process. The various possible explanations for this phenomenon are discussed.
Effects of an extremely low frequency electromagnetic field on the cell division rate and plasma membrane of Paramecium tetraurelia
Authors: Dihel Larry E. , Smith‐Sonneborn Joan , Middaugh C. Russell
Published: February 2006

The eukaryotic protozoan, Paramecium, was examined as a model for effects of pulsated electromagnetic fields (PEMF) on cells. A 72‐Hz PEMF similar to fields employed clinically increased cell division rates in Paramecium by 8.5%. Two calcium transport mutants of these organisms showed differential responses to the same field. Verapamil, a calcium channel blocker, abolished any effect of PEMFs on cell division rates. A fluorescent probe that is thought to sense changes in membrane potential also manifested an altered response in the PEMF‐exposed cells whereas a fluorescent lipid bilayer fluidity probe produced evidence of decreased membrane fluidity in the exposed cells. An effect of PEMFs on ion transport mediated by either a direct or indirect effect on the cell membrane is suggestd by these studies.
Specific absorption rate in rats exposed to 2,450‐MHz microwaves under seven exposure conditions
Authors: Chou Chung‐Kwang , Guy Arthur W. , McDougall John A. , Lai Henry
Published: February 2006

Both positive and negative biological effects of microwaves on drug actions in rats exposed to 1‐mW/cm2, 2,450‐MHz microwaves have been reported by several investigators. We conducted dosimetry studies for seven different exposure conditions to determine whether these different results could be due to the rats having been exposed differently. They included anterior and posterior exposures in a circular waveguide, near field, far field with E‐or H‐field parallel to the long axis of the body and dorsal exposure in a miniature anechoic chamber with E‐ or H‐field parallel to the long axis of the body. The average specific absorption rates (SARs) in the head, tail, and body of the exposed rats were measured by means of a calorimetry system. The local SARs at eight locations in the brain were determined by temperature measurement with Vitek probes. Intensive coupling of energy to the tail when it was exposed parallel to the E‐field was shown by thermography. For the same average incident power density, the average SARs in the heads of rats were about two times higher in the circular waveguide than for other exposures. The local SARs in the brain varied for different exposure conditions. Statistical comparisons of SARs under the different exposure conditions are presented.
60‐Hz electric fields: Detection by female rats
Authors: Stern Sander , Laties Victor G.
Published: February 2006

Female rats were trained to detect a vertical, 60‐Hz electric field using the same apparatus and procedure we used previously to study behavioral detection of the field by male rats. Each rat was trained individually to press a lever in the presence of the field and not to press in its absence. Correct detections occasionally produced a food pellet. The probability of detecting the field increased as field strength increased. The threshold of detection —ie, the field strength required for detections at a probability of 0.5 after correction for errors—varied among rats between 3 and 10 kV/m. Behavioral detection by female rats was indistinguishable from that by male rats.
Effects of electric field exposure on some indices of CNS arousal in the mouse
Authors: Blackwell R. P. , Reed A. L.
Published: February 2006

Mice given ELF electric field exposures of 50‐400 Vm−10 at frequencies of 15, 30, and 50 Hz failed to display any significant changes in barbiturate sleeping time or exploratory activity.
Blood‐brain barrier permeation in the rat during exposure to low‐power 1.7‐GHz microwave radiation
Authors: Ward T. R. , Ali J. S.
Published: February 2006

The permeability of the blood‐brain barrier to high‐ and low‐molecular‐weight compounds has been measured as a function of continuous‐wave (CW) and pulsed‐microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [14C] sucrose and [3H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7‐GHz CW and pulsed (0.5‐μs pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham‐exposed animals.
Low‐voltage ELF electric field measurements in ionic media
Authors: Gundersen R. , Greenebaum B.
Published: February 2006

Low‐voltage electric fields were measured in conductive tissue culture media using three techniques: voltage slope, current density‐conductivity, and dipole methods. All three methods tested yielded comparable results. However, all three techniques have associated errors. These errors fall into three major categories: 1) those associated with the measurement equipment, 2) those associated with electrodes, and 3) errors in cross‐sectional area measurements. Each source of error is discussed so that all can be taken into account during construction and/or testing of exposure equipment.
Potassium ion influx measurements on cultured Chinese hamster cells exposed to 60‐Hertz electromagnetic fields
Authors: Stevenson Anita P. , Tobey Robert A.
Published: February 2006

Potassium ion influx was measured by monitoring 42KCI uptake by Chinese hamster ovary (CHO) cells grown in suspension culture and exposed in the culture medium to 60–Hz electromagnetic fields up to 2.85 V/m. In the presence of the field CHO cells exhibited two components of uptake, the same as previously observed for those grown under normal conditions; both these components of influx were decreased when compared to sham‐exposed cells. Although decreases were consistently observed in exposed cells when plotted as logc of uptake, the differences between the means of the calculated fluxes of exposed and sham‐exposed cells were quite small (on the order of 4–7%). When standard deviations were calculated, there was no significant difference between these means; however, when time‐paired uptake data were analyzed, the differences were found to be statistically significant. Cells exposed only to the magnetic field exhibited similar small decreases in influx rates when compared to sham‐exposed cells, suggesting that the reduction in K+ uptake could be attributed to the magnetic field. Additionally, intracellular K+ levels were measured over a prolonged exposure period (96 h), and no apparent differences in intracellular K+ levels were observed between field‐exposed and shamexposed cultures. These results indicate that high‐strength electric fields have a small effect on the rate of transport of potassium ions but no effect on long‐term maintenance of intracellular K+.
Microwave radiation absorption in the rat: Frequency‐dependent SAR distribution in body and tail
Authors: D'Andrea John A. , Emmerson Rita Y. , Bailey Cory M. , Olsen Richard G. , Gandhi Om P.
Published: February 2006

Experiments were conducted using twin‐well calorimetry to determine the averaged whole‐body specific absorption rate (SAR) for rat carcasses exposed to 360, 700, 915, and 2,450 MHz CW radiation in an anechoic chamber. All exposures were done with the long axis of the rat in an E‐polarization. Additional experiments were conducted using a fiber optical temperature probe to determine local SAR in the brain, esophagus, colon, rectum, and tail during microwave exposure. The whole‐body averaged SAR for the radiation frequencies examined follows a nonmonotonic function with 700 MHz as the resonant frequency. This result agrees with previous analytical estimates. Local SARs within the body and tail are nonuniform with significant frequency‐specific hotspots in the colon, rectum, and tail.
Microwave‐induced changes in nerve cells: Effects of modulation and temperature
Authors: Arber Simon L. , Lin James C.
Published: February 2006

Helix aspersa neurons were irradiated with continuous‐wave (CW) and noise‐amplitudemodulated microwaves (carrier frequency 2450 MHz, 20% AM, 2 Hz‐20 kHz) in a specially designed waveguide exposure system. Continuous‐wave microwave irradiations were conducted at 8°, 21°, and 28°C, while noise‐modulated irradiation was performed at 21°C. The results showed that exposure of snail neurons to CW microwaves for 60 min at 12.9 W/kg inhibited spontaneous activity and reduced input resistance at 8° and 21°C but not at 28°C. The relative decrease in resistance at 21°C was half that at 8°C. Exposure of neurons to noise‐modulated microwaves at 6.8 and 14.4 W/kg predominately caused excitatory responses characterized by augmented membrane resistance and the appearance of greater activity. The effect differed qualitatively from the inhibition observed with continuous, unmodulated microwave irradiation.
Effect of microwave irradiation (2.45 GHz, CW) on egg weight loss, egg hatchability, and hatchling growth of the Coturnix quail
Authors: Byman David , Battista Sam P. , Wasserman Fred E. , Kunz Thomas H.
Published: February 2006

Fertile eggs of the Coturnix quail were exposed twice a day for 30 min to 2.45‐GHz continuous wave radiation at power densities of 25 or 50 mW cm−2 throughout the 17‐day incubation period. Other eggs were exposed to 20°C or 24°C temperatures twice daily. Repeated exposures to 20°C, 24°C, or 25 mW cm−2 did not reduce hatchability. Irradiation at 50 mW cm−2 lowered hatchability, probably as a result of high egg temperatures. Hatchlings that had been irradiated by microwaves as embryos had normal growth rates and no obvious developmental abnormalities.
Erythrocyte hemolysis by radiofrequency fields
Authors: Cleary Stephen F. , Liu Li‐Ming , Garber Francine
Published: February 2006

A field‐strength‐dependent hemolytic effect of continuous‐wave radiofrequency (RF) exposure in vitro has been demonstrated. Erythrocytes in whole heparinized rabbit blood were hemolyzed by a 2‐h exposure to 50‐ or 100‐MHz RF fields at field strengths of greater than 4 V/cm. An effect of comparable magnitude resulted from exposure to 10‐MHz RF at a field strength of 9 V/cm. Sample temperatures were maintainted at 22.5° ± 0.2°C. There was no apparent involvement of heating or temperature gradients, nor were there any RF exposure effects on cellular K+ or Na+ concentration, nor on pH. The mechanism of the hemolytic effect is not known. Since the percentage of lysed erythrocytes was less than 1% and there was an absence of effects on cellular cation concentrations, RF radiation may have irreversibly altered the plasma membrane permeability of a sensitive subpopulation of red cells (possibly aged cells) leading to osmotic lysis. RF radiation at these frequencies appears to affect red cells in a manner that is qualitatively and quantitatively different from microwave radiation.
Thermoregulatory consequences of long‐term microwave exposure at controlled ambient temperatures
Authors: Adair Eleanor R. , Spiers Donald E. , Rawson Robert O. , Adams Barbara W. , Sheldon Douglas K. , Pivirotto Philip J. , Akel Gillian M.
Published: February 2006

This study was designed to identify and measure changes in thermoregulatory responses, both behavioral and physiological, that may occur when squirrel monkeys are exposed to 2450‐MHz continuous wave microwaves 40 hr/week for 15 weeks. Power densities of 1 or 5 mW/cm2 (specific absorption rate = 0.16 W/kg per mW/cm2) were presented at controlled environmental temperatures of 25, 30, or 35°C. Standardized tests, conducted periodically, before, during, and after treatment, assessed changes in thermoregulatory responses. Dependent variables that were measured included body mass, certain blood properties, metabolic heat production, sweating, skin temperatures, deep body temperature, and behavioral responses by which the monkeys selected a preferred environmental temperature. Results showed no reliable alteration of metabolic rate, internal body temperature, blood indices, or thermoregulatory behavior by microwave exposure, although the ambient temperature prevailing during chronic exposure could exert an effect. An increase in sweating rate occurred in the 35°C environment, but sweating was not reliably enhanced by microwave exposure. Skin temperature, reflecting vasomotor state, was reliably influenced by both ambient temperature and microwaves. The most robust consequence of microwave exposure was a reduction in body mass, which appeared to be a function of microwave power density.
Noninvasive thermometry using multiple‐frequency‐band radiometry: A feasibility study
Authors: Prionas Stavros D. , Hahn G. M.
Published: February 2006

The potential use of multiple‐frequency‐band radiometry as a means of noninvasive sensing of one‐dimensional temperature profiles is presented in this communication. The radiative energy transfer equation is solved numerically. Ideal‐condition thermal noise spectra and distributions of received energy, associated with specific temperature‐depth profiles, are presented. Performance characteristics are discussed.