bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermoregulatory adjustments in squirrel monkeys exposed to microwaves at high power densities
Authors: Candas Victor , Adair Eleanor R. , Adams Barbara W.
Published: February 2006

The present study was undertaken to investigate the thermal adjustments of squirrel monkeys exposed in a cold environment to relatively high energy levels of microwave fields. The animals (Saimiri sciureus) were equilibrated for 90 min to a cool environment (Ta = 20°C) to elevate metabolic heat production (M). They were then exposed for brief (10‐min) or long (30‐min) periods to 2,450‐MHz continuous‐wave microwaves. Power densities (MPD) were 10, 14, 19, and 25 mW/cm2 during brief exposures and 30, 35, 40, and 45 mW/cm2 during long exposures (rate of energy absorption: SAR = 0.15 [W/kg]/ [mW/cm2]). Individual exposures were separated by enough time to allow physiological variables to return to baseline levels. The results confirm that each microwave exposure induced a rapid decrease in M. In a 20°C environment, the power density of a 10‐min exposure required to lower M to approximate the resting level was 35 mW/cm2 (SAR = 5.3 W/kg). During the long exposures, 20 min was needed to decrease M to its lowest level. Cessation of irradiation was associated with persistence of low levels of M for periods that depended on the power density of the preceding microwave exposure. Vasodilation, as indexed by changes in local skin temperature, occurred at a high rate of energy absorption (SAR = 4.5 W/kg) and was sufficient to prevent a dramatic increase in storage of thermal energy by the body; vasoconstriction was reinstated after termination of irradiation. Patterns of thermophysiological responses confirm the influence both of peripheral and of internal inputs to thermoregulation in squirrel monkeys exposed to microwaves in a cool environment.
Dielectric properties of developing rabbit brain at 37°C
Authors: Thurai M. , Steel M. C. , Sheppard R. J. , Grant E. H.
Published: February 2006

The dielectric properties of developing rabbit brain were measured at 37°C between 10 MHz and 18 GHz using time domain and frequency domain systems. The results show a variation with age of the dielectric properties of brain. An analysis of the data suggests that the water dispersion in the brain of newly born animals can be represented by a Debye equation. This dispersion increases in complexity with age, and there is evidence of a smaller additional relaxation process centered around 1 GHz. It is concluded that the principal contribution to this subsidiary dispersion region arises from water of hydration.
Growth rate and mitotic index analysis of Vicia faba L. Roots exposed to 60‐Hz electric fields
Authors: Inoue M. , Miller Morton W. , Cox Christopher , Carstesen E. L.
Published: February 2006

Growth, mitotic index, and growth rate recovery were determined for Vicia faba L. roots exposed to 60‐Hz electric fields of 200, 290, and 360 V/m in an aqueous inorganic nutrient medium (conductivity 0.07–0.09 S/m). Root growth rate decreased in proportion to the increasing strength; the electric field threshold for a growth rate effect was about 230 V/m. The induced transmembrane potential at the threshold exposure was about 4–7 mV. The mitotic index was not affected by an electric field exposure sufficient to reduce root growth rate to about 35% of control. Root growth rate recovery from 31–96% of control occurred in 4 days after cessation of the 360 V/m exposure. The results support the postulate that the site of action of the applied electric fields is the cell membrane.
Auditory response in rats exposed to 2,450 MHz electromagnetic fields in a circularly polarized waveguide
Authors: Chou Chung‐Kwang , Yee Kuo‐Chiang , Guy Arthur W.
Published: February 2006

Rats were exposed to 2,450‐MHz pulsed microwave fields in a circularly polarized waveguide. The threshold incident energy density per pulse was about 1.5 to 3 μJ/cm2 over the range 1–10 μs. The corresponding whole‐body averaged specific absorption of energy was 0.9 to 1.8 mJ/kg per pulse. The same response was evoked when the incident energy density or absorbed energy density per pulse was the same, regardless of the pulse widths.
Ion exposure chambers for small animals
Authors: Charry Jonathan M. , Bailey William H. , Shapiro Monte H. , Weiss Jay M.
Published: February 2006

Ion exposure chambers that have been designed and tested for use in biological and behavioral research with small animals are described in this report. The chambers exhibit an acceptable degree of uniformity in ion concentration, current density, and electric field within the exposure area. Gaseous by‐products of corona discharge (O3 and NO2) have been measured and found to be < .01 ppm and < .1 ppm, respectively. Filtered air is fed to the individual exposure chambers, and temperature and humidity are well controlled. Noise due to corona and the air delivery system has been measured.
Influence of pre‐ and postnatal exposure of rats to 2.45‐GHz microwave radiation on neurobehavioral function
Authors: Galvin Michael J. , Tilson Hugh A. , Mitchell Clifford L. , Peterson John , McRee Donald I.
Published: February 2006

Rats exposed to microwaves prenatally (2,450 MHz, 10 mW/cm2, 3 h/day, days 5–20 of gestation) or perinatally (same as above plus days 2–20 postnatally) were examined by a neurobehavioral test battery on postnatal days 30 and 100. Body mass, locomotor activity, startle to acoustic and air‐puff stimuli, fore‐ and hindlimb grip strength, negative geotaxis, reaction to thermal stimulation, and swimming endurance were assessed. The prenatally and the perinatally exposed rats (male and female) weighed more than sham‐exposed rats at 30, but not at 100, days of age. In addition, the perinatally exposed animals had less swimming endurance at 30, but not at 100, days of age relative to sham‐exposed rats. For the other measures, only the air‐puff startle response was altered and was limited to the prenatally exposed female pups; ie, at postnatal day 30, the startle response was increased in magnitude, and at postnatal day 100, the response was decreased. No other reliable effects were observed. In a second experiment, rats treated as described above were examined for alterations in body mass, locomotor activity, reaction to air‐puff stimuli, reaction to thermal stimulation, and swimming endurance at postnatal days 30–36. Again, perinatally exposed rats were larger in body mass and had less swimming endurance compared with sham‐exposed rats. The latency to the air‐puff startle response was longer in female pups exposed prenatally. These data indicate that altered endurance and gross motor activity result from perinatal exposure to microwave irradiation.
Conductivity values of tissue culture medium from 20°C to 40°C
Authors: Mazzoleni A. P. , Sisken B. F. , Kahler R. L.
Published: February 2006

Few studies are available that relate conductivity and temperature in solutions commonly used in tissue culture media. The purpose of this paper is to provide equations relating conductivity and temperature (in the range 20°C–40°C) for five solutions: 0.9% saline, MEM (Minimum Essential Media), horse serum, MEM with 1% horse serum, and MEM with 10% horse serum.
Dose‐response relationship between body temperature and birth defects in radiofrequency‐irradiated rats
Authors: Lary Joseph M. , Conover David L. , Johnson Peggy H. , Hornung Richard W.
Published: February 2006

Five groups of pregnant Sprague‐Dawley rats were irradiated for 10–40 min on gestation day 9 in a 27.12‐MHz radiofrequency field at a magnetic field strength of 55 A/m and an electric field strength of 300 V/m. The specific absorption rate was 10.8 ± 0.3 W/kg. Exposures were terminated after the rat's colonic temperature reached 41.0°C, 41.5°C, 42.0°C, 42.5°C, or 43.0°C. A control group was sham irradiated at 0 A/m and 0 V/m on gestation day 9, whereas a second control group was untreated. The incidence of both birth defects and prenatal death was directly related to maternal body temperature once a temperature threshold was exceeded. The temperature threshold for both types of effects was approximately 41.5°C. A few pregnant rats died after exposure to 43.0°C, and higher temperatures were nearly always lethal.
Absence of chromosomal damage in human lymphocytes exposed to microwave radiation with hyperthermia
Authors: Lloyd D. C. , Saunders R. D. , Moquet J. E. , Kowalczuk C. I.
Published: February 2006

Specimens of human blood were exposed to 0, 4, 40, 100, and 200 Wkg−1 of 2.45 GHz microwave radiation for 20 minutes. The blood temperature was carefully controlled so that it rose from 37 to 40°C. Cultured lymphocytes were examined for induced chromosomal damage but no effect in excess of background was observed.
Intracellular recording during magnetic field application to monitor neurotransmitter release events: Methods and preliminary results
Authors: Gundersen R. , Greenebaum B. , Schaller M.
Published: February 2006

A method for simultaneous magnetic field application and intracellular recording is presented. A little used method for magnetic field application was exploited; the field generator consisted of a flat copper sheet through which current was passed to generate a magnetic field. The resultant magnetic field was relatively homogeneous, exhibiting a variation of ± 5%. This compact, current‐sheet field generator was mounted on the condensor of a microscope. The current induced in the intracellular electrode was reduced by injecting current equal and opposite to the induced current into the microelectrode. This step reduces the possibility of cellular effects and voltage artifacts due to the induced electrode current. The technique was used to conduct preliminary studies on the effects of extremely low frequency (ELF) linearly and circularly polarized magnetic fields (1.0 Gauss, 60 and 70 Hz) on miniature end plate potential (mepp) frequency (frequency of neurotransmitter release events) of rat flexor digitorum brevis muscle. The same synapse was utilized for both the sham‐exposed control and the exposed experimental halves of an experiment. After 10 min of exposure to a 60‐Hz linear field, mepp frequency was significantly increased by 12%, but exposure to a 60‐Hz circular field did not significantly alter mepp frequency. Exposure to a 70‐Hz linear field did not significantly change mepp frequency, but application of a 70‐Hz circular field appears to decrease mepp frequency by 4%. These results indicate that both types of magnetic fields can alter mepp frequency, depending upon the frequency and configuration of the field.
Effects of sinusoidal 60‐Hz electric and magnetic fields on ATP and oxygen levels in the slime mold, Physarum polycephalum
Authors: Marron M. T. , Goodman E. M. , Greenebaum B. , Tipnis P.
Published: February 2006

We have previously reported that exposing the vegetative plasmodia stage of Physarum polycephalum to either individual or simultaneously applied electric and magnetic fields (45–75 Hz, 0.14–2.0 G, and 0.035–0.7 V/m) lengthens their mitotic cycle, depresses their rate of reversible shuttle streaming, and lowers their respiration rate. In this article we report the effects of simultaneously applied electromagnetic fields (60 Hz, 1.0 G, 1.0 V/m), electric fields only (60 Hz, 1.0 V/m), magnetic fields only (60 Hz, 1.0 G) on the haploid amoeba of Physarum exposed for 120–180 days. Statistically significant depressions (about 8–11%) in ATP levels were observed with all field conditions; however, respiration was significantly decreased only when amoebae were subjected to either combined fields or electric fields alone. Magnetic fields alone failed to induce a significant decrease in respiration.
Interaction of ethanol and microwaves on the blood‐brain barrier of rats
Authors: Neilly Joseph P. , Lin James C.
Published: February 2006

The combined effects of ethanol and microwaves on the permeation of Evans blue dye through the mammalian blood‐brain barrier was studied in male Wistar rats. Anesthetized rats were infused through a cannula in the left femoral vein with 0.1, 0.3, 0.5 or 0.7 grams of absolute ethanol per kilogram of body mass. A control group was given 0.7 g/kg of isotonic saline. The left hemisphere of the brain was irradiated by 3.15‐GHz microwave energy at 3.0 W/cm2 rms for 15 min. The rat's rectal temperature was maintained at 37.0°C. Immediately after irradiation, 2% Evans blue dye in saline (2.0 ml/kg body mass) was injected through the cannula. The results show that as the quantity of alcohol was increased, the degree of staining was decreased or eliminated. The temperature of the irradiated area of the brain increased for the first 4 to 5 minutes of irradiation and then stabilized for the remainder of the irradiation period. The steady‐state temperature was highest in animals receiving saline or the smallest dose of alcohol. As the quantity of alcohol was increased, the steady‐state temperature was reduced. These results indicate that ethanol inhibits microwave‐induced permeation of the blood‐brain barrier through reduced heating of the brain.
Transcriptional patterns in the X chromosome of Sciara coprophila following exposure to magnetic fields
Authors: Goodman Reba , Abbott Joan , Henderson Ann S.
Published: February 2006

We previously demonstrated that exposure of salivary gland cells of the dipteran, Sciara coprophila, to either asymmetrical or symmetrical changing magnetic fields results in an increase in the incorporation of radioactive uridine into RNA. The present report is an analysis of the grain count distribution over the X chromosome of Sciara in transcription autoradiograms following exposure of the salivary gland cells to two pulsed magnetic signals and a 72‐Hz sine wave signal. The results show augmented uptake of 3H‐uridine into nascent RNA chains following short exposures of the cells to magnetic fields. Transcription is augmented in previously active loci, as well as at chromosome regions that are not detectable as active in control cells. The quantitative pattern of RNA synthesis in transcription autoradiograms is hypothesized to be signal specific on the basis of differences in grain counts over significantly labelled chromosome sites.
Comparison of the dielectric properties of normal and wounded human skin material
Authors: Gabriel C. , Bentall R. H. , Grant E. H.
Published: February 2006

Measurements have been made of the permittivity and conductivity of normal and wounded human skin material over the frequency range 10 MHz‐10 GHz. The permittivity of the wounded tissue was found to be about 12% higher than that of the normal tissue. A similar percentage increase was observed for the conductivity. These differences are attributed to the presence of a higher proportion of bulk water in the wounded material.
Simulated biological materials for electromagnetic radiation absorption studies
Authors: Hartsgrove G. , Kraszewski A. , Surowiec A.
Published: February 2006

For the study of electromagnetic dosimetry and hyperthermia, it is necessary to simulate human biological materials. This can be done by chemical mixtures that are described in this paper. Formulas are presented for simulating bone, lung, brain, and muscle tissue in the frequency range of 100 MHz to 1 GHz. By using these preparations a realistic equivalent to the human body can be constructed.
Simple method to measure power density entering a plane biological sample at millimeter wavelengths
Authors: Shen Z.‐Y. , Birenbaum L. , Chu A. , Motzkin S. , Rosenthal S. , Sheng K.‐M.
Published: February 2006

A simple method for measuring microwave power density is described. It is applicable to situations where exposure of samples in the near field of a horn is necessary. A transmitted power method is used to calibrate the power density entering the surface of the sample. Once the calibration is available, the power density is known in terms of the incident and reflected powers within the waveguide. The calibration has been carried out for liquid samples in a quartz cell. Formulas for calculating specific absorption rate (SAR) are derived in terms of the power density and the complex dielectric constant of the sample. An error analysis is also given.
Specific absorption rate in humans in vivo at radio frequencies
Authors: Kraszewski Andrzej , Hartsgrove George , Stuchly Stanislaw S. , Stuchly Maria A.
Published: February 2006

Specific absorption rates were measured in three locations of humans exposed in the far field at 160, 350, and 915 MHz. Values obtained for six males are compared with data for a full‐scale homogeneous model of man.
Normalizing the thermal effects of radiofrequency radiation: Body mass versus total body surface area
Authors: Gordon Christopher J.
Published: February 2006

The current guideline for exposure to radiofrequency radiation (RFR) was developed through assessment of the biological effects data collected primarily from the rat. The consensus that a lack of hazardous biological effects occurred below a whole‐body‐averaged specific absorption rate (SAR) of 4.0 W/kg led to the proposition of a 0.4 W/kg guideline with a built‐in safety factor of 10. This paper demonstrates that if the RFR absorption rate in the rat had been normalized with respect to total body surface area rather than body mass, the exposure guideline would be 2.3 W/m2, which translates to an SAR of approximately 0.06 W/kg for an adult human. It is further shown that a given RFR absorption rate, normalized as a fraction of a species' heat loss per unit of surface area, is independent of body mass over a range of 0.03‐100 kg; however, a normalization of the RFR absorption rate to heat loss per unit of body mass is highly dependent on the species' mass. Normalizing the rate of RFR absorption to the surface area of the rat indicates that the current RFR exposure guideline of 0.4 W/kg may be too high.
Experimental method for the hyperthermic treatment of cells in tissue culture: Initial application to pancreatic cancer cells
Authors: Chang Barbara K. , Joines William T. , Gregory Judith A.
Published: February 2006

Hyperthermia is attractive as a potential adjunctive modality in the treatment of cancer, especially those cancers that are more resistant to conventional modalities. In the present study, we characterized the response of two pancreatic cancer cell lines to hyperthermia alone. In so doing, we utilized and characterized a novel exposure system that heats by 915‐MHz continuous wave microwave (MW) radiation, with microprocessor control of the power input via temperature monitoring of the sample and simultaneous visualization and recording of temperature parameters. Samples, consisting of cells in 25‐cm2 culture flasks with 10 ml of medium, were exposed to MWs in a stripline for 1 h at MW‐induced temperatures of 37, 41.5, 42.5, 43.5, or 44.5 °C. The specific absorption rate was 132 W/kg for all temperatures. In addition, 37 °C waterbath controls were concurrently run. The colony formation assay was used to assess cytotoxicity. No significant difference was found between 37 °C waterbath and 37 °C MW controls. Significant differences in the thermosensitivity of the two cell lines were found, with the most drug‐sensitive cell line showing the greatest thermosensitivity. However, hyperthermia alone was not very effective as a single cytotoxic modality in either cell line. The MW‐hyperthermia‐induction system provided precise, automated temperature control (± 0.2 °C), and ease of utilization and data management.
Developmental studies of hanford miniature swine exposed to 60‐Hz electric fields
Authors: Sikov M. R. , Rommereim D. N. , Beamer J. L. , Buschbom R. L. , Kaune W. T. , Phillips R. D.
Published: February 2006

Evaluations of reproductive and developmental toxicology, including teratology, were included as part of a broad screening study in Hanford Miniature swine (HMS) to detect effects of exposure to electric fields. One group (E) was exposed to a uniform, vertical, 60‐Hz, 30‐kV/m electric field for 20 h/day, 7 days/week sham‐exposed (SE) swine were housed in a separate, environmentally equivalent building. The first generation (F0) gilts were bred after 4 months of study; some were killed for teratologic assays at 100 days of gestation (dg), and the others produced an F1 generation of offspring. The pooled incidence of terata in these litters (teratologic assays and live births) was similar in the E and SE groups. The F0 females, which produced the F1 generation, were bred again after 18 months of exposure and were killed at 100 dg. Malformation incidence in E litters (75%) was significantly greater than in SE litters (29%). No consistent differences in litter size, fetal mass, or mass of fetal organs were detected. The F1 gilts were bred at 18 months of age; defective offspring were found in significantly more of the E litters (71 %) than in SE litters (33%). These F1 females were bred again 10 months later and teratologic assays were performed on their second litters at 100 dg. The percentage of litters with malformed fetuses was essentially identical in the E and SE groups (70% and 73%, respectively). There appears to be an association between chronic exposure to a strong electric field and developmental effects in swine, although the change in incidence of malformations between generations and between the first and second breedings makes it impossible to conclude unequivocally that there is a cause‐and‐effect relation.
Reproduction and development in rats chronologically exposed to 60‐Hz electric fields
Authors: Rommereim D. N. , Kaune W. T. , Buschbom R. L. , Phillips R. D. , Sikov M. R.
Published: February 2006

Previous studies have raised the possibility of reproductive and developmental changes in miniature swine chronically exposed to a strong 60‐Hz electric field. Two replicate experiments on rats were performed to determine if similar changes could be detected in animals exposed under a comparable regime, which was based on average, induced‐current densities and on the chronology of reproductive development, as dosimetrically and biologically scaled. Beginning at three months of age, female rats of the F0 generation and their subsequent offspring were chronically exposed to a 60‐Hz electric field (100 kV/ m unperturbed) for 19 h/day for the duration of experimentation.

After four weeks of exposure, F0 female rats were mated to unexposed male rats during the field‐off period. No significant developmental effects were detected in their litters, confirming our previous results with swine and rats. The F0 females were mated for a second time at 7.2 months of age, and the fetuses were evaluated shortly before term. In the first experiments, the incidence of intrauterine mortality was significantly less in exposed than in sham‐exposed litters, and there was a tendency (P = 0.12) for an increased incidence of malformed fetuses in exposed litters. Neither end point was significantly affected in the second experiment.

Copulatory behavior of the female F1 offspring, which were bred at three months of age, was not affected in either experiment. There was a statistically significant decrease in the fertility of F1 exposed females and a significant increase in the fraction of exposed litters with malformed fetuses in the first experiment; both end points were essentially the same in the sham and exposed groups of the second experiment.

That the significant effects detected in the first experiment were not seen in the second may be attributed to random or biological variation. Alternatively, the finding may indicate that the response threshold for induction of malformations lies near 100 kV/m.
A finite‐difference electromagnetic deposition/thermoregulatory model: Comparison between theory and measurements
Authors: Spiegel R. J. , Fatmi M. B. E. , Ward T. R.
Published: February 2006

The rate of the electromagnetic energy deposition and the resultant thermoregulatory response of a block model of a squirrel monkey exposed to plane‐wave fields at 350 MHz were calculated using a finite‐difference procedure. Noninvasive temperature measurements in live squirrel monkeys under similar exposure conditions were obtained using Vitek probes. Calculations exhibit reasonable correlation with the measured data, especially for the rise in colonic temperature.
Thermoregulatory responses of the immature rat following repeated postnatal exposures to 2,450‐MHz microwaves
Authors: Spiers Donald E. , Adair Eleanor R.
Published: February 2006

This study was designed to determine the changes that occur in the thermoregulatory ability of the immature rat repeatedly exposed to low‐level microwave radiation. Beginning at 6–7 days of age, previously untreated rats were exposed to 2,450‐MHz continuous‐wave microwaves at a power density of 5 mW/cm2 for 10 days (4 h/day). Microwave and sham (control) exposures were conducted at ambient temperatures (Ta) which represent different levels of cold stress for the immature rat (ie, “exposure” Ta = 20 and 30 °C). Physiological tests were conducted at 5–6 and 16–17 days of age, in the absence of microwaves, to determine pre‐ and postexposure responses, respectively. Measurements of metabolic rate, colonic temperature, and tail skin temperature were made at “test” Ta = 25.0, 30.0, 32.5, and 35.0 °C. Mean growth rates were lower for rats exposed to Ta = 20°C than for those exposed to Ta = 30°C, but microwave exposure exerted no effect at either exposure Ta. Metabolic rates and body temperatures of all exposure groups were similar to values for untreated animals at test Ta of 32.5 °C and 35.0 °C. Colonic temperatures of rats repeatedly exposed to sham or microwave conditions at exposure Ta = 20 °C or to sham conditions at exposure Ta = 30 °C were approximately 1°C below the level for untreated animals at test Ta of 25.0 °C and 30.0 °C. However, when the exposure Ta was warmer, rats exhibited a higher colonic temperature at these cold test Ta, indicating that the effectiveness of low‐level microwave treatment to alter thermoregulatory responses depends on the magnitude of the cold stress.
Residential magnetic and electric fields
Authors: Kaune W. T. , Stevens R. G. , Callahan N. J. , Severson R. K. , Thomas D. B.
Published: February 2006

A magnetic flux density (MFD) and electric‐field (E‐field) data‐acquisition system was built for characterizing extremely low‐frequency fields in residences. Every 2 min during 24‐h periods, MFD and E‐field measurements were made in 43 homes in King, Pierce, and Snohomish counties of Washington State. The total electrical energy used in each residence during the 24‐h measurement period was also recorded, and maps were drawn to scale of the distribution wiring within 43 m (140 ft) of these homes. Finally, on a separate date, field measurements were made in each home during an epidemiological interview. The results of this study can be summarized as follows: 1) 24‐h‐average MFD measured at two separate points in the family room were correlated, as were a 24‐h‐average bedroom measurement and the mean of the two family‐room measurements. 2) The 24‐h‐average family‐room MFD and E‐field measurements were uncorrelated. 3) The 24‐h‐average total harmonic distortions of family‐room MFD and E‐fields were less than about 24% and 7%, respectively. 4) Residential MFD exhibited a definite 24‐h (diurnal) cycle. 5) The 24‐h‐average and interviewer‐measured MFD were correlated. 6) Residential 24‐h‐average MFD were correlated with the wiring code developed by Wertheimer and Leeper. 7) An improved prediction of 24‐h‐average residential MFD was obtained using the total number of service drops, the distance to neighboring transmission lines, and the number of primary phase conductors.
Test for the effects of 60‐Hz magnetic fields on fecundity and development in Drosophila
Authors: Walters Ellen , Carstensen Edwin L.
Published: February 2006

Ramirez et al (1983) reported reduced egg laying by Drosophila melanogaster and reduced survival of those eggs to adulthood when adult flies were exposed to magnetic fields. In a similar study, no effects from exposures of Drosophila to 1‐mT, 60‐Hz magnetic fields were found.
Absorption of microwave radiation by the anesthetized rat: Electromagnetic and thermal hotspots in body and tail
Authors: D'Andrea John A. , Emmerson Rita Y. , Dewitt John R. , Gandhi Om P.
Published: February 2006

Anatomic variability in the deposition of radiofrequency electromagnetic energy in mammals has been well documented. A recent study [D'Andrea et al., 1985] reported specific absorption rate (SAR) hotspots in the brain, rectum and tail of rat carcasses exposed to 360‐ and to 2,450‐MHz microwave radiation. Regions of intense energy absorption are generally thought to be of little consequence when predicting thermal effects of microwave irradiation because it is presumed that heat transfer via the circulatory system promptly redistributes localized heat to equilibrate tissue temperature within the body. Experiments on anesthetized, male Long‐Evans rats (200–260 g) irradiated for 10 or 16 min with 2,450, 700, or 360 MHz radiation at SARs of 2 W/kg, 6 W/kg, or 10 W/ kg indicated that postirradiation localized temperatures in regions previously shown to exhibit high SARs were appreciably above temperatures at body sites with lower SARs. The postirradiation temperatures in the rectum and tail were significantly higher in rats irradiated at 360 MHz and higher in the tail at 2,450 MHz than temperatures resulting from exposure to 700 MHz. This effect was found for whole‐body‐averaged SARs as low as 6 W/kg at 360 MHz and 10 W/kg at 2,450 MHz. In contrast, brain temperatures in the anesthetized rats were not different from those measured in the rest of the body following microwave exposure.
Thermal cataract formation in rabbits
Authors: Kramár Piró , Harris Carrol , Guy Arthur W.
Published: February 2006

Intraocularly circulating hot water was used to produce cataracts in nine eyes of seven rabbits by maintaining their retrolental temperatures between 43 °C and 45 °C. A rapid rate of heating (1.3 °C/min) plus a sharp temperature gradient across the eye may have been contributing factors in the consistent production of cataracts at these temperatures. Biomicroscopy and light microscopy showed lens changes similar to those associated with acute exposure to microwave radiation. These findings support the assumption that microwave cataractogenesis is due to the local production of elevated temperatures.
Effects of pulsed extremely‐low‐frequency magnetic fields on skin wounds in the rat
Authors: Ottani V. , De Pasquale V. , Govoni P. , Franchi M. , Ruggeri A. , Zaniol P.
Published: February 2006

Rats with skin‐wounds surgically created on their backs were exposed immediately after surgery and every 12 h thereafter to pulsed, extremely‐low‐frequency magnetic fields. The shape of the pulse was a positive triangle (50 Hz, 8 mT peak). The rate of healing of skin wounds was evaluated macroscopically and by light and electron microscopy at 6, 12, 21, and 42 days after the operation. A significant increase in the rate of wound contraction was found in rats treated with magnetic fields. Forty‐two days after surgery all treated animals show fully closed wounds, while control rats at the same time intervals still lacked a final 6% of the wound surface to be covered. Treated rats showed earlier cellular organization, collagen formation and maturation, and a very early appearance of newly formed vascular network.
Microwave attenuation of ethanol‐induced hypothermia: Ethanol tolerance, time course, exposure duration, and dose response studies
Authors: Hjeresen Dennis L. , Francendese Albert , O'Donnell James M.
Published: February 2006

Four experiments were conducted to quantify the reported attenuation by microwave (MW) irradiation of ethanol‐induced hypothermia. In one experiment rats were irradiated (continuous wave 2.45 GHz, specific absorption rate = 0.3 W/kg) or sham irradiated for 45 min, injected with 3.6 g/kg, 20% (v/v) ethanol (EtOH) or saline (NaCl) i.p. Colonic temperature was monitored at 20‐min intervals for 2 h. This procedure was repeated for 8 days to determine the rate of tolerance development to the hypothermic effect of ethanol. While MW irradiation did significantly attenuate EtOH‐induced hypothermia, it did not enhance or retard the rate of tolerance development. To determine the duration of irradiation necessary to attenuate EtOH‐induced hypothermia, groups of rats were irradiated or sham irradiated for 5, 15, 30, or 60 min prior to EtOH injection and subsequent temperature measurements. The attenuation was apparent only after 60 min of irradiation. To determine the duration of the attenuation effect after irradiation, rats were injected with EtOH or NaCl at 0, 30, 60, 120, or 480 min after 45 min of irradiation or sham irradiation. The attenuation effect was apparent among rats injected 0 to 30 min after irradiation and for the first 40 min for groups injected at 120 min. Additional rats were injected with NaCl or 0.9, 1.8, or 2.7 g/kg of EtOH i.p. following 45 min of irradiation or sham irradiation to determine if the attenuation effect depends on the dose of EtOH administered. Attenuation of EtOH‐induced hypothermia was more apparent at lower doses of EtOH than at higher doses. These results indicate that the effect is an acute response to irradiation, and rule out several other potential explanations.
B16 melanoma development in black mice exposed to low‐level microwave radiation
Authors: Santini R. , Hosni M. , Pacheco H. , Deschaux P.
Published: February 2006

The effect of low‐level microwave exposure, 2,450 MHz, at a power density of 1 mW/cm2 and specific absorption rate of 1.2 mW/g, continuous waves (CW) or pulsed waves (PW), 2.5 h/day, 6 sessions/week until death (up to 690 h of irradiation), has been studied in black C57/6J mice with B16 melanoma. The results show that no significant effects are observed on tumor development or on survival times compared to controls, or between CW‐ and PW‐treated animals.
Effect of ambient levels of power‐line‐frequency electric fields on a developing vertebrate
Authors: Blackman Carl F. , House Dennis E. , Benane Shawnee G. , Joines William T. , Spiegel Ronald J.
Published: February 2006

Fertilized eggs of Gallus domesticus were exposed continuously during their 21‐day incubation period to either 50‐ or 60‐Hz sinusoidal electric fields at an average intensity of 10 Vrms/m. The exposure apparatus was housed in an environmental room maintained at 37°C and 55–60% relative humidity (RH). Within 1.5 days after hatching, the chickens were removed from the apparatus and tested. The test consisted of examining the effect of 50‐ or 60‐Hz electromagnetic fields at 15.9 Vrms/m and 73 nTrms (in a local geomagnetic field of 38 μT, 85°N) on efflux of calcium ions from the chicken brain. For eggs exposed to 60‐Hz electric fields during incubation, the chicken brains demonstrated a significant response to 50‐Hz fields but not to 60‐Hz fields, in agreement with the results from commercially incubated eggs [Blackman et al., 1985a]. In contrast, the brains from chicks exposed during incubation to 50‐Hz fields were not affected by either 50‐ or 60‐Hz fields. These results demonstrate that exposure of a developing organism to ambient power‐line‐frequency electric fields at levels typically found inside buildings can alter the response of brain tissue to field‐induced calcium‐ion efflux. The physiological significance of this finding has yet to be established.
Effects of static magnetic fields on diffusion in solutions
Authors: Kinouchi Y. , Tanimoto S. , Ushita T. , Sato K. , Yamaguchi H. , Miyamoto H.
Published: February 2006

Static magnetic fields affect the diffusion of biological particles in solutions through the Lorentz force and Maxwell stress. These effects were analyzed theoretically to estimate the threshold field strength for these effects. Our results show that the Lorentz force suppresses the diffusion of charged particles such as Na+, K+, Ca2+, Cl‐, and plasma proteins. However, the threshold is so high, i.e., more than 104 T, that the Lorentz force does not affect the ion diffusion at typical field strengths (a few Tesla at most). Since the threshold of gradient fields for producing a change in ion diffusion through the Maxwell stress is more than 105 T2/m for paramagnetic molecules (FeCl3, O2) and plasma proteins, their diffusion would be unaffected by typical gradient fields (100 T2/m at most) and even by high gradient fields (less than 105 T2/m) used in magnetic separation techniques. In contrast, movement of deoxygenated erythrocytes and FeCl3 colloids (more than 103 molecules) is influenced by the usual gradient fields due to a volume effect.
Exposure of mammalian cells to 60‐Hz magnetic or electric fields: Analysis for DNA single‐strand breaks
Authors: Reese J. A. , Jostes R. F. , Frazier M. E.
Published: February 2006

Chinese hamster ovary (CHO) cells were exposed for 1 h to 60‐Hz magnetic fields (0.1 or 2 mT), electric fields (1 or 38 V/m), or to combined magnetic and electric fields (2 mT and 38 V/m, respectively). Following exposure, the cells were lysed, and the DNA was analyzed for the presence of single‐strand breaks (SSB), using the alkaline elution technique. No significant differences in numbers of DNA SSB were detected between exposed and sham‐exposed cells. A positive control exposed to X‐irradiation sustained SSB with a dose‐related frequency. Cells exposed to nitrogen mustard (a known cross‐linking agent) and X‐irradiation demonstrated that the assay could detect cross‐linked DNA under our conditions of electric and magnetic field exposures.
Suppression of T‐lymphocyte cytotoxicity following exposure to 60‐Hz sinusoidal electric fields
Authors: Lyle Daniel B. , Ayotte Robert D. , Sheppard Asher R. , Adey W. Ross
Published: February 2006

A significant 25% inhibition (P < .005) of allogeneic cytotoxicity of the target cell MPC‐11 by the murine cytotoxic T‐lymphocyte line CTLL‐1 was observed when the 4‐h cytotoxicity assay was conducted immediately following a 48‐h pre‐exposure of the effector lymphocytes to a 10‐mV/cm (rms) 60‐Hz sinusoidal electric field. At 1.0 mV/cm a significant 19% inhibition (P < .0005) was seen. At 0.1 mV/cm a nonsignificant 7% inhibition of cytotoxicity was noted. When the 4‐h cytotoxicity assay was conducted in the presence of the field using previously unexposed effector lymphocytes, cytotoxicity was not significantly reduced. Cell proliferation in the presence of interleukin‐2 was unaffected by the field. These data suggest a dose response and threshold (between 0.1 and 1.0 mV/cm) for inhibition of cytotoxicity in clonal T‐lymphocytes by exposure to a 60‐Hz sinusoidal electric field. These results suggest mechanisms by which 60‐Hz electric fields could affect the function of cells of the immune system.
Slow potentials and spike unit activity of the cerebral cortex of rabbits exposed to microwaves
Authors: Chizhenkova R. A.
Published: February 2006

Unanesthetized rabbits exposed to 12.5‐cm microwaves at a field intensity of 40 mW/cm2 in the region of the head showed an increase in the number of slow waves and spindleshaped firings in the EEG and a change in the discharge frequency of neurons in the visual cortex in 41–52% of the cases. An enhancement of the evoked response of visual cortex neurons to light was observed in 61% of the cases and a facilitation of the driving response in 80% of all cases. It is concluded that the evoked response is a more sensitive indicator of the microwave effect than background activity. The effects of the fields were most distinctly observed with the driving response.
Microwave effect on camphor binding to rat olfactory epithelium
Authors: Philippova T. M. , Novoselov V. I. , Bystrova M. F. , Alekseev S. I.
Published: February 2006

Microwave radiation decreased specific camphor binding to a membrane fraction of rat epithelium but not to a Triton X‐100 extract of this fraction. Inhibition of the ligand binding did not depend on the modulation frequency of the microwave field in the region 1–100 Hz and was not a linear funcion of specific absorption rate (SAR). The decreased ligand binding was due to a shedding or release of the specific camphor‐binding protein from the membrane into solution. It is highly probable that several other membrane proteins may be shed into solution during microwave exposure.
Microwave effects on acetylcholine‐induced channels in cultured chick myotubes
Authors: D'Inzeo G. , Bernardi P. , Grassi F. , Zani B. M. , Eusebi F. , Tamburello C.
Published: February 2006

The behavior of cultured myotubes from chick embryos exposed to microwaves has been experimentally analyzed. Recordings of acetylcholine‐induced currents have been obtained via patch‐clamp techniques using both cell‐attached (single‐channel current recording) and whole‐cell (total current recording) configurations. During the exposure to low‐power microwaves the frequency of the ACh‐activated single channel openings decreased, while the ACh‐induced total current showed a faster falling phase. Channel open time and conductance were not affected by microwave irradiation. It is concluded that the exposure to microwaves increases the rate of desensitization and decreases the channel opening probability. The nonthermal origin and the molecular interaction mechanisms governing these electromagnetic‐induced effects are discussed.
Magnetic fields and time dependent effects on development
Authors: Martin A. H.
Published: February 2006

Pulsed, extremely‐low‐frequency electromagnetic fields caused a significant increase in abnormalities in the developing chick embryo. The effect was observed when the field was presented during the first 24 h of incubation; no significant effect was observed with exposure from 24 to 48 h of incubation.
Comparison of 60‐Hz electric fields and incandescent light as aversive stimuli controlling the behavior of rats
Authors: Stern Sander , Laties Victor G.
Published: February 2006

Rats were exposed to two procedures which enabled them to press a lever to turn off a 90 or 100 kV/m 60‐Hz electric field or, later in the study, illumination from an incandescent lamp. Under one procedure, a response turned off the stimulus for a fixed duration, after which the stimulus was turned on again. A response during the off‐period restarted the fixed duration. None of the rats turned the field off reliably. Next, under an alternative procedure, pressing one lever turned the field off; pressing the other lever turned it back on; responding under those conditions differed little from that seen at 0 kV/m. Under both procedures, when illumination from an incandescent lamp served as the stimulus, each rat did turn the stimulus off, and performances varied with stimulus intensity. The results show that a 100 kV/m 60‐Hz electric field is not sufficient to function as an aversive stimulus under two procedures where illumination from a lamp does function as an aversive stimulus.
Multiple power‐density windows and their possible origin
Authors: Blackman C. F. , Kinney L. S. , House D. E. , Joines W. T.
Published: February 2006

We have previously reported that in vitro exposure of chick forebrain tissue to 50‐MHz radiofrequency (RF) electromagnetic radiation, amplitude modulated (AM) at 16 Hz, would enhance the efflux of calcium ions within only two power‐density ranges: one from 1.44 to 1.67 mW/cm2, and the other including 3.64 mW/cm2. No effect on efflux occurred at 0.37, 0.72, 2.17, and 4.32 mW/cm2. We confirmed and extended these results by testing at another set of power densities, which included the range of the previous study. Forebrain tissue from 1–7‐day‐old chickens was labeled in vitro with radioactive calcium ions (30 min, at 37 °C), rinsed, placed in a physiological salt solution, and then exposed for 20 min to 50‐MHz radiation, AM at 16 Hz, in a transverse electric and magnetic field (TEM) cell maintained at 37 °C. The solution was then assayed for radioactive calcium activity. A power‐density series was tested. An enhanced efflux of calcium ions was found at 1.75, 3.85, 5.57, 6.82, 7.65, 7.77, and 8.82 mW/cm2; no change was observed at 0.75, 2.30, 4.50, 5.85, 7.08, 8.19, 8.66, 10.6, and 14.7 mW/cm2. Power density is converted to specific absorption rate (SAR) by 0.36 mW/kg per mW/cm2. Even the highest SAR tested (0.005 W/kg) is much too low to result in generalized heating of the sample and thus to be the underlying cause of the enhanced response. A hypothetical mechanism is proposed involving dynamic systems that may account for the power‐density dependency as well as for part of the frequency dependency observed with both modulated RF radiation and extremely‐low‐frequency (ELF) fields.
Thresholds of cat cochlear nucleus neurons to microwave pulses
Authors: Seaman Ronald L. , Lebovitz Robert M.
Published: February 2006

Action potentials of neurons in cat dorsal and posteroventral cochlear nuclei were recorded extracellularly with glass microelectrodes while the head of the cat was exposed to microwave pulses at 915 MHz using a diathermy applicator. Response thresholds to acoustic tones, acoustic clicks, and microwave pulses were determined for auditory units with characteristic frequencies (CFs) from 278 Hz to 39.2 kHz. Tests with pulsatile stimuli were performed for durations of 20–700 μs, principally 20, 70, and 200 μs. Brainstem midline specific absorption rate (SAR) threshold was as small as 11.1 mW/g per pulse, and specific absorption (SA) threshold was as small as 0.6 μJ/g per pulse. Microwave thresholds were generally lower for CF less than 9 kHz, as were most acoustic thresholds. However, microwave threshold was only weakly related to click threshold and CF‐tone threshold of each unit.
Electroreception and magnetoreception in simple and complex organisms
Authors: Tenforde T. S.
Published: February 2006

A brief summary is presented of electroreception and magnetoreception mechanisms in bacteria and in more complex organisms such as avians, bees, and various aquatic animals. This article is a prologue to the series of three reviews written by specialists in the field of electroreception and magnetoreception that appear in this issue of Bioelectromagnetics.
Chronic exposure of primates to 60‐Hz electric and magnetic fields: I. exposure system and measurements of general health and performance
Authors: Wolpaw Jonathan R. , Seegal Richard F. , Dowman Robert
Published: February 2006

We exposed pigtailed macaques (Macaca nemestrina) to electric (E) and magnetic (B) fields at strengths of 3 kV/m and 0.1 G, 10 kV/m and 0.3 G, and 30 kV/m and 0.9 G for three 21 day segments. These three exposure segments were preceded and followed by 21 day sham exposure segments. Additional animals received only sham exposure for five 21 day segments. Detailed description of the exposure chamber and field generation apparatus is given. We evaluated measures of animal well‐being, including weight, blood chemistry, blood cell counts, and performance on a simple motor task, and performed postmortem examinations. Reliable and consistent results were obtained throughout data collection. None of the measures evaluated was significantly affected by E‐ and B‐field exposures. Data obtained during actual exposure segments were not distinguishable from those obtained during the initial and final sham exposure segments, nor were they different from data obtained from the sham‐exposed animals. Thus, field exposure had no apparent effects on general health or performance.