bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of microwave exposure on the hamster immune system. III. Macrophage resistance to vesicular stomatitis virus infection
Authors: Rao G. Rama , Cain C. A. , Tompkins W. A. F. 
Published: February 2006

AbstractExposure of hamsters to microwave (MW) energy (2.45 GHz, 25 mW/cm2, 1 h) resulted in activation of peritoneal macrophages (PM) to a viricidal state restricting the replication of vesicular stomatitis virus (VSV). The PM from MW‐exposed hamsters were viricidal as early as 1 day after exposure and remained active for 5 days. Immunization of hamsters with vaccinia virus induced viricidal PM by 3 to 4 days and they remained active for 7 days. To test the hypothesis that thermogenic MW exposure results in the release of endotoxin across the intestinal epithelium which subsequently activates PM, hamsters were injected with lipopolysaccharide (LPS) and their viricidal activity was studied. Lipopolysaccharide in vitro (0.2 μg) and in vivo (0.5 μg) activated macrophages to a viricidal state. When administered in vivo, LPS (0.5 μg) activated macrophages as early as 1 day and the activity remained for 3 days. While MW exposure of PM in vitro failed to induce viricidal activity, exposure of PM to LPS in vitro induced strong viricidal activity. This suggests that the in vivo response of PM to MW is an indirect one, which is consistent with the hypothesis that MW‐induced PM viricidal activity may be mediated via LPS. In preliminary experiments, MW exposure resulted in extended survival time for hamsters challenged with a lethal dose of vesicular stomatitis virus, supporting the concept that MW‐activated PM may be a useful therapeutic modality.
Effects of ELF (1–120 Hz) and modulated (50 Hz) RF fields on the efflux of calcium ions from brain tissue in vitro
Authors: Blackman C. F. , Benane S. G. , House D. E. , Joines W. T. 
Published: February 2006

AbstractWe have previously shown that 16‐Hz, sinusoidal electromagnetic fields can cause enhanced efflux of calcium ions from chick brain tissue, in vitro, in two intensity regions centered on 6 and 40 Vp‐p/m. Alternatively, 1‐Hz and 30‐Hz fields at 40 Vp‐p/m did not cause enhanced efflux. We now demonstrate that although there is no enhanced efflux associated with a 42‐Hz field at 30, 40, 50, or 60 Vp‐p/m, a 45‐Hz field causes enhanced efflux in an intensity range around 40 Vp‐p/m that is essentially identical to the response observed for 16‐Hz fields. Fields at 50 Hz induce enhanced efflux in a narrower intensity region between 45 and 50 Vp‐p/m, while radiofrequency carrier waves, amplitude modulated at 50 Hz, also display enhanced efflux over a narrow power density range. Electromagnetic fields at 60 Hz cause enhanced efflux only at 35 and 40 Vp‐p/m, intensities slightly lower than those that are effective at 50 Hz. Finally, exposures over a series of frequencies at 42.5 Vp‐p/m reveal two frequency regions that elicit enhanced efflux—one centered on 15 Hz, the other extending from 45 to 105 Hz.
Effects of continuous‐wave, pulsed, and sinusoidal‐amplitude‐modulated microwaves on brain energy metabolism
Authors: Sanders Aaron P. , Joines William T. , Allis John W. 
Published: February 2006

AbstractA comparison of the effects of continuous‐wave, sinusoidal‐amplitude‐modulated, and pulsed square‐wave‐modulated 591‐MHz microwave exposures on brain energy metabolism was made in male Sprague‐Dawley rats (175–225 g). Brain NADH fluorescence, adenosine triphosphate (ATP) concentration, and creatine phosphate (CP) concentration were determined as a function of modulation frequency. Brain temperatures of animals were maintained between −0.1 and −0.4°C from the preexposure temperature when subjected to as much as 20 mW/cm2 (average power) CW, pulsed, or sinusoidal‐amplitude modulated 591‐MHz radiation for 5 min. Sinusoidal‐amplitude‐modulated exposures at 16–24 Hz showed a trend toward preferential modulation frequency response in inducing an increase in brain NADH fluorescence. The pulse‐modulated and sinusoidal‐amplitudemodulated (16 Hz) microwaves were not significantly different from CW exposures in inducing increased brain NADH fluorescence and decreased ATP and CP concentrations. When the pulse‐modulation frequency was decreased from 500 to 250 pulses per second the average incident power density threshold for inducing an increase in brain NADH fluorescence increased by a factor of 4—ie, from about 0.45 to about 1.85 mW/cm2. Since brain temperature did not increase, the microwave‐induced increase in brain NADH and decrease in ATP and CP concentrations was not due to hyperthermia. This suggests a direct interaction mechanism and is consistent with the hypothesis of microwave inhibition of mitochondrial electron transport chain function of ATP production.
Effects of 2.45‐GHz microwaves on primate corneal endothelium
Authors: Kues Henry A. , Hirst Lawrence W. , Lutty Gerard A. , D'Anna Salvatore A. , Dunkelberger Gregory R. 
Published: February 2006

AbstractBoth eyes of anesthetized cynomolgus monkeys (Macaca fascicularis) were irradiated with 2.45‐GHz microwaves, either pulsed or continuous wave. In vivo corneal endothelial abnormalities were observed by specular microscopy and confirmed through histologic techniques after a 16‐ to 48‐hour postexposure period. Pulsed microwaves with an average power density of 10 mW/cm2 (equivalent to a specific absorption rate (SAR) = 2.6 W/kg) produced these effects, while levels of 20‐30 mW/cm2 (equivalent to a SAR = 5.3 to 7.8 W/kg) with continuous wave irradiation were required to produce similar changes.
Thermoregulatory adjustments in squirrel monkeys exposed to microwaves at high power densities
Authors: Candas Victor , Adair Eleanor R. , Adams Barbara W. 
Published: February 2006

AbstractThe 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

AbstractThe 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

AbstractGrowth, 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

AbstractRats 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

AbstractIon 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

AbstractRats 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

AbstractFew 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

AbstractFive 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

AbstractSpecimens 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

AbstractA 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

AbstractWe 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

AbstractThe 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

AbstractWe 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

AbstractMeasurements 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

AbstractFor 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

AbstractA 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

AbstractSpecific 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

AbstractThe 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.