bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of localized pulsed electromagnetic fields on tail‐suspension osteopenia in growing mice
Authors: Simske S. J. , Wachtel H. , Luttges M. W. 
Published: February 2006

AbstractPulsed magnetic fields (PEMFs) have been used effectively to treat bone fractures and sciatic‐nerve‐section‐induced osteopenias. Properly applied PEMFs are presumed to stimulate osteogenesis. Mouse‐tail suspension has been implemented as a means of inducing an osteopenic response in the long bones of the hind limbs. To evaluate localized PEMF effects, the mouse‐suspension model was modified to accommodate the use of miniature wire coils affixed directly to the rear legs. Laterally and axially orientated PEMF effects were compared. Three test groups of mice included (C) control mice, (S) tail‐suspended mice with treatment apparatus attached, and (SF) tail‐suspended mice with apparatus attached and PEMFs delivered. The SF group was divided into mice receiving axial or lateral PEMFs. Significant bone changes occurred in suspended as compared with control mice after a 2‐week test period. The PEMF mice showed significantly fewer osteopenic effects than did untreated, suspended mice. These findings are based on biomechanical measures of stiffness, strength, ductility, and energy as well as whole‐bone mass and porosity. The effects of PEMFs on these properties differ for axial and lateral exposures. The results are discussed in terms of mechanisms underlying PEMF effects.
Miniature‐probe measurements of electric fields and currents induced by a 60‐Hz magnetic field in rat and human models
Authors: Miller Douglas L. 
Published: February 2006

AbstractA miniaturized probe was designed and built to provide detailed data on fields induced by a uniform 60‐Hz magnetic field in homogeneous models of rat and human. The probe employed three silver wires twisted and potted in an 8‐cm hypodermic needle. The exposed tips of the wires formed three sensing electrodes with a centered ground; highly sensitive voltage measurements were enabled by a lock‐in amplifier. Tests were conducted in a 1‐mT rms field that was uniform within ± 5%. The models were made by casting 1.5% agar at 1‐S/m conductivity into plastic‐foam molds. The rat model was scaled 1:1 as an adult (22 cm length; mass about 640 g). The human model was scaled 1:4 as an adult (height = 46.5 cm; mass 1.4 kg). The probe was inserted into each model in several regions, and readings of induced fields were made under different exposure geometries. Maximal strengths of fields induced near the surface of the torso were as high as 120 μV/cm in the laterally exposed rat model. Data extrapolated from the quarter‐scale human model revealed that an induced field as high as 700 μV/cm could occur at the torso of a frontally exposed human adult. An overall size‐scale factor of about 5 appears to be appropriate for experimental exposures of rats that are intended to simulate currents induced in human beings by magnetic fields. The average strength of electric fields induced in the torso by a 1‐mT magnetic field is comparable to that by a vertical electric‐field at 60 kV/m and 28 kV/m, respectively, for the rat and human.
An increase in the negative surface charge of U937 cells exposed to a pulsed magnetic field
Authors: Smith Orla M. , Goodman Eugene M. , Greenebaum Ben , Tipnis Pratima 
Published: February 2006

AbstractPulsed magnetic fields have been used to enhance healing of bone fractures and purportedly of lesions in soft tissue. However, their mechanism of action is poorly understood. We report changes in the plasma membrane of a nonadherent mammalian cell line, U937, which was exposed to a 25‐pps magnetic field for 48 hours. Aqueous polymer two‐phase partition studies showed that magnetic‐field‐exposed cells exhibited an increased negative surface charge but membrane hydrophobicity was not significantly altered. The observed increase in membrane electronegativity of exposed cells did not reflect a significant change in growth rate.
Thermal and metabolic responsiveness of Japanese quail embryos following periodic exposure to 2,450 MHz microwaves
Authors: Spiers Donald E. , Baummer Sheila C. 
Published: February 2006

AbstractTwo studies were performed to determine if repeated exposure of the avian egg to microwaves can alter metabolism, temperature, and growth rate of embryos. Another aim was to supplement conventional heating with microwave heating and provide an optimal temperature for growth. Japanese quail (Coturnix coturnix japonica) eggs were exposed from day 1 through 15 of incubation (8 h/day) to sham or microwave (2,450 MHz) irradiation. Microwave exposures were at two power densities, 5 or 20 mW/cm2, and at three ambient temperatures (Tas), 30.0, 33.1, or 35.4 °C. Specific absorption rates for unincubated and 15‐day‐old incubated eggs were, respectively, 0.76 and 0.66 W kg−1 mW−1 cm−2 (i.e., 3.8 and 3.3 W/kg at 5 mW/cm2 and 15.2 and 13.2 W/kg at 20 mW/cm2). Eggs were concurrently sham exposed at each of five Tas, ranging from 27.9 to 37.5 °C. Tests were conducted during the 16th day of incubation (i.e., I day post‐treatment), in the absence of microwaves, to determine metabolic rate of embryos and internal and external egg temperatures at different Tas. Repeated exposures to microwaves at 5 and 20 mW/cm2 at the same Ta (30 °C) increased wet‐embryo mass on the 16th day by an average, respectively, of 9% and 61% when compared with predicted masses for embryos exposed at the same Ta in the absence of microwave radiation. There was no reliable indication, from post‐treatment tests and comparisons with control embryos of similar mass, that repeated exposure to microwave radiation resulted in abnormal physiological development. Microwave radiation can be used to increase egg temperature and embryonic growth rate at Tas below normal incubation level without altering basic metabolic and thermal characteristics of the developing bird.
A dosimeter for assessment of exposures to ELF fields
Authors: Héroux Paul 
Published: February 2006

AbstractThere are currently no biological indicators of electromagnetic field exposure to aid investigation of the biological effects of ELF fields, but this hiatus is partly compensated for by the ease with which the external fields can be measured. The subject of this report is a small electronic instrument that can log electric‐, magnetic‐, and transient‐field intensities of individual subjects for a duration of two weeks, thus allowing exposure to be assessed in considerable detail. A preliminary survey conducted with the instrument has shown clear differences in domestic and occupational exposures of specific groups. Simple analytical models can be fitted to the field‐exposure data by adjusting a few parameters such as current, intensity, and distance. Such modeling may be increasingly useful as the data base on exposures expands.
Absence of a synergistic effect between moderate‐power radio‐frequency electromagnetic radiation and adriamycin on cell‐cycle progression and sister‐chromatid exchange
Authors: Ciaravino Victor , Meltz Martin L. , Erwin David N. 
Published: February 2006

AbstractIn our laboratories we are conducting investigations of potential interactions between radiofrequency electromagnetic radiation (RFR) and chemicals that are toxic by different mechanisms to mammalian cells. The RFR is being tested at frequencies in the microwave range and at different power levels. We report here on the I) ability of simultaneous RFR exposures to alter the distribution of cells in first and second mitoses from that after treatment by adriamycin alone, and 2) on the ability of simultaneous RFR exposure to alter the extent of sister chromatid exchanges (SCEs) induced by adriamycin alone. This chemical was selected because of its reported mechanism of action and because it is of interest in the treatment of cancer. In our studies, Chinese hamster ovary (CHO) cells were exposed for 2 h simultaneously to adriamycin and pulsed RFR at a frequency of 2,450 MHz and a specific absorption rate of 33.8 W/Kg. The maximal temperature (in the tissue‐culture medium) was 39.7 ± 0.2 °C. The experiments were controlled for chemical and RFR exposures, as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin, and the RFR did not change the number of SCEs that were induced by the adriamycin, which adriamycin is known to affect cells by damaging their membranes and DNA.
Morphological and electrophysiological changes produced by electrical stimulation in cultured neuroblastoma cells
Authors: Krauthamer Victor , Bekken Marijke , Horowitz Jennifer L. 
Published: February 2006

AbstractElectric fields, which were equivalent to those generated by medical devices, were applied to cultured neuroblastoma cells (mouse and human) to test for morphological damage and to establish damage thresholds. Each of two methods of applying fields permitted flow of electrical current and minimized exposure of cells to electrode‐breakdown products. One method consisted of a pair of parallel wires in a Petri dish by which current was delivered within a fixed volume of flowing tissue‐culture media. With the other method, the cells were held in a confined geometrical chamber and current was applied via agar bridges. Under a given set of stimulation parameters, damage was found to be variable from cell to cell. By changing the strength of the electric field (frequency and duration of stimulation held constant), thresholds of several V/cm were found above which cell damage could be reliably produced. Depending on the intensity of the field, damage took the form of cell lysis or damage to neurites. Intracellular recordings from the mouse neuroblastoma cells revealed a correlation between a decline in resting transmembrane potential and stimulus intensity. Human neuroblastoma cells were less susceptible to damage than were the mouse neuroblastoma cells, given the same strength of applied electric fields.
Modification of the 1979 “Denver wire code” for different wire or plumbing types
Authors: Leeper Ed , Wertheimer Nancy , Savitz David , Barnes Frank , Wachtel Howard 
Published: February 2006

AbstractThis article examines “wire configuration coding” as used to estimate relative residential AC magnetic field exposure in epidemiological studies–and the need to alter such coding for time or locations other than those in which the code was developed. Effects of different secondary wire practices are particularly examined.
Japanese encephalitis virus (JEV): Potentiation of lethality in mice by microwave radiation
Authors: Lange David G. , Sedmak J. 
Published: February 2006

AbstractThe expression of Japanese Encephalitis Virus (JEV) lethality in mice requires entry of the virus into the central nervous system. This entry is presumably through the capillary endothelial cells (CEC), because entry between CECs is inhibited by bands of circumferential tight‐junctions. A viremic stage occurs during the first 4 to 5 days after JEV administration in mice, and both microwave radiation (2.45‐GHz, continuous wave, 10‐min exposure) and hypercarbia were employed to increase CEC permeability to JEV. Exposure to microwaves at power densities of 10–50 mW/cm2 resulted in a dose‐dependent increase in JEV‐induced lethality. Mice did not become tolerant or sensitized to microwave potentiation of JEV‐induced mortality because 4 daily exposures at 10 or 50 mW/cm2 (SARS, ∼ 24–98 W/kg) did not alter the lethality pattern to subsequent microwave radiation of JEV‐exposed animals. Similarly, hypercarbia (5, 10, and 20% CO2) was observed to produce a dose‐dependent increase in JEV‐induced lethality. Both microwave radiation and hypercarbia are thought to promote pinocytosis in CNS capillary endothelial cells. This may be one mechanism by which they enhance JEV‐induced lethality in adult Swiss‐Cox mice.
Investigation of AC‐DC magnetic field effects in planar phospholipid bilayers
Authors: Durney Carl H. , Kaminski Mark , Anderson Allen A. , Bruckner‐Lea Cindy , Janata Jiri , Rappaport Catherine 
Published: February 2006

AbstractObservations recently reported by others indicate that a combination of a weak dc magnetic field and extremely‐low‐frequency ac magnetic field can produce resonant effects in biological systems. We report measurements of the effects of combined dc and ac magnetic fields on the dc current through channel‐free planar phospholipid membranes. The combined dc‐ac magnetic fields did affect the dc current through planar phospholipid membranes, but not in every membrane, and not consistently at the same values of magnetic flux density and frequency. None of our measurements showed resonant response akin to the cyclotron‐like resonance reported in diatoms [Smith et al., 1987] and lymphocytes [Liboff et al., 1987].
Single vs. Repeated microwave exposure: Effects on benzodiazepine receptors in the brain of the rat
Authors: Lai H. , Carino M. A. , Horita A. , Guy A. W. 
Published: February 2006

AbstractWe studied the effects of single (45 min) and repeated (ten daily 45‐min sessions) microwave exposures (2450‐MHz, 1 mW/cm2, average whole‐body SAR of 0.6 W/kg. pulsed at 500 pps with pulse width of 2 μs) on the concentration and affinity of benzodiazepine receptors in the cerebral cortex, hippocampus, and cerebellum of the rat. We used a receptor‐binding assay with 3H‐flunitrazepam as ligand. Immediately after a single exposure, an increase in the concentration of receptor was observed in the cerebral cortex, but no significant effect was observed in the hippocampus or cerebellum. No significant change in binding affinity of the receptors was observed in any of the brain‐regions studied. In rats subjected to repeated exposures, no significant change in receptor concentration was found in the cerebral cortex immediately after the last exposure, which may indicate an adaptation to repeated exposures. Our data also show that handling and exposure procedures in our experiments did not significantly affect benzodiazepine receptors in the brain. Because benzodiazepine receptors in the brain are responsive to anxiety and stress, our data support the hypothesis that low‐intensity microwave irradiation can be a source of stress.
Sex‐linked recessive lethal test of Drosophila melanogaster after exposure to 50‐Hz magnetic fields
Authors: Otaka Yoshihisa , Kitamura Satoshi , Furuta Masako , Shinohara Akemi 
Published: February 2006

AbstractTo determine whether a 50‐Hz magnetic field will induce mutations, a sex‐linked recessive lethal test of Drosophila melanogaster was performed. Adult flies were exposed at an rms flux density of 500 μT or 5 mT to the homogeneous field of a Helmholtz coil. The ambient field to which controls were exposed was less than 1 μT. Exposures took place continuously for 13 to 14 days, which correspond to the life cycle of Drosophila at 25°C About 10,000 X‐chromosomes were tested at each flux density. Recessive lethal mutation rates of 0.13, 0.21, and 0.18 percent were observed, respectively, for control, 500‐μT, and 5‐mT conditions. By the Kastenbaum‐Bowman significance test, the recessive lethal mutation rates in the 500‐μT and 5‐mT conditions did not differ from the mutation rate of controls.
Microwave‐specific heating affects gene expression
Authors: Saffer Jeffrey D. , Profenno Louis A. 
Published: February 2006

AbstractThe effects of low‐level microwave radiation on gene expression in Escherichia coli have been examined in a sensitive model. We confirm the previously reported existence of an increase in β‐galactosidase expression by microwave radiation—an increase not duplicated by bulk heating. However, the effect was not frequency dependent and appeared to be due to heating effects peculiar to microwaves. These results indicate that small thermal gradients may be a source of biological effects of non‐ionizing radiation.
Modification of membrane fluidity in melanin‐containing cells by low‐level microwave radiation
Authors: Phelan Anne M. , Lange David G. , Kues Henry A. , Lutty Gerard A. 
Published: February 2006

AbstractThe treatment of a B16 melanoma cell line with 2.45‐GHz pulsed microwaves (10 mW/cm2, 10‐μs pulses at 100 pps, 1‐h exposure; SAR, 0.2 W/kg) resulted in changes of membrane ordering as measured by EPR (electron paramagnetic resonance) reporter techniques. The changes reflected a shift from a more fluid‐like phase to a more solid (ordered) state of the cell membrane. Exposure of artificially prepared liposomes that were reconstituted with melanin produced similar results. In contrast, neither B16 melanoma cells treated with 5‐Bromo‐2‐Deoxyuridine (3 μg/day × 7 days) to render them amelanotic, nor liposomes prepared without melanin, exhibited the microwave‐facilitated increase of ordering. Inhibition of the ordering was achieved by the use of superoxide dismutase (SOD), which strongly implicates oxygen radicals as a cause of the membrane changes. The data indicate that a significant, specific alteration of cell‐membrane ordering followed microwave exposure. This alteration was unique to melanotic membranes and was due, at least in part, to the generation of oxygen radicals. © 1992 Wiley‐Liss, Inc.
Calcium binding to metallochromic dyes and calmodulin in the presence of combined, AC‐DC magnetic fields
Authors: Bruckner‐Lea Cindy , Durney Carl H. , Janata Jiri , Rappaport Catherine , Kaminski Mark 
Published: February 2006

AbstractThe possibility that weak, ac and dc magnetic fields in combination may affect binding equilibria of calcium‐ions (Ca2+) was investigated with two metallochromic dyes as calcium‐binding molecules: murexide and arsenazo III. Calcium‐dye equilibria were followed by measuring solution absorbances with a fiber‐optic spectrophotometer. A Ca2+‐arsenazo solution was also used indirectly to monitor the binding of Ca2+ to calmodulin. Parallel, ac and dc magnetic fields were applied to each preparation. The ac magnetic field was held constant during each of a series of experiments at a frequency in the range between 50 and 120 Hz (sine wave) or at 50 pps (square wave) and at an rms flux density in the range between 65 and 156 μT. The dc magnetic field was then varied from 0 to 299 μT at 1.3 μT increments. The magnetic fields did not measurably affect equilibria in the binding of metallochromic dyes or calmodulin to Ca2+. © 1992 Wiley‐Liss, Inc.
ELF exposure facility for human testing
Authors: Cohen Harvey D. , Graham Charles , Cook Mary R. , Phelps James W. 
Published: February 2006

AbstractA laboratory facility specifically designed for controlled human exposure to 60‐Hz electric (0 to 16 kV/m) and magnetic (0 to 32 A/m, B = 0 to 40 μT) fields has been constructed. The facility presents uniform fields under controlled temperature and humidity. Special control systems allow collection of physiological data during, as well as before and after, exposure to electric fields at strengths to 16 kV/m under verified double‐blind control. Exposure to continuous or intermittent fields is possible in the facility. The capability of obtaining physiological data during actual exposure to constant or intermittent, 60‐Hz fields, and of doing so without either the subject or the experimenter being aware of actual field conditions, is a critical factor in valid experimentation. © 1992 Wiley‐Liss, Inc.
ELF in vitro exposure systems for inducing uniform electric and magnetic fields in cell culture media
Authors: Bassen H. , Litovitz T. , Penafiel M. , Meister R. 
Published: February 2006

AbstractMany in vitro experiments on the biological effects of extremely low frequency (ELF) electromagnetic fields utilize a uniform external magnetic flux density (B) to expose biological materials. A significant number of researchers do not measure or estimate the resulting electric field strength (E) or current density (J) in the sample medium. The magnitude and spatial distribution of the induced E field are highly dependent on the sample geometry and its relative orientation with respect to the magnetic field. We have studied the E fields induced in several of the most frequently used laboratory culture dishes and flasks under various exposure conditions. Measurements and calculations of the E field distributions in the aqueous sample volume in the containers were performed, and a set of simple, quantitative tables was developed. These tables allow a biological researcher to determine, in a straightforward fashion, the magnitudes and distributions of the electric fields that are induced in the aqueous sample when it is subjected to a uniform, sinusoidal magnetic field of known strength and frequency. In addition, we present a novel exposure technique based on a standard organ culture dish containing two circular, concentric annular rings. Exposure of the organ culture dish to a uniform magnetic field induces different average electric fields in the liquid medium in the inner and outer rings. Results of experiments with this system, which were reported in a separate paper, have shown the dominant role of the magnetically induced E field in producing specific biological effects on cells, in vitro. These results emphasize the need to report data about the induced E field in ELF in‐vitro studies, involving magnetic field exposures. Our data tables on E and J in standard containers provide simple means to enable determination of these parameters. © 1992 Wiley‐Liss, Inc.
Measurement of magnetically induced electric fields in conductive media near a 60 Hz current‐carrying wire
Authors: Robertson‐De Mers K. A. , Miller Douglas L. 
Published: February 2006

AbstractElectric fields induced in a conductive body by the magnetic field of a current‐carrying wire were analyzed theoretically and experimentally to assess the dosimetric importance of highly nonuniform, field‐exposure conditions. Experimentation revealed that a 60‐Hz magnetic field was inversely proportional to the radius of a wire bundle carrying 100 A within a 0.5‐m2 test area. A miniaturized electric field probe was used to measure the electric fields induced in 5‐cm‐deep, saline‐filled models. In the theoretical analysis, numerical estimates of induced fields were made by a spreadsheet method. The theoretical calculations and the measured values of induced electric fields were generally in good agreement. The induced fields were in a plane perpendicular to a vertically incident magnetic field; the maximally induced fields were in areas nearest the wire bundle. The strength of the induced field increased with model size: from 96 μV/cm in a 10 × 10 cm model to 176 μV/cm in a 40 × 40 cm model. The strength of the field induced in a 20 × 20 cm model decreased with increasing model‐to‐wire spacing: from 132 μV/cm for a 1‐cm spacing (2‐mT maximum, incident field) to 50 μV/cm for a 6‐cm spacing (0.33‐mT maximum). The results indicate that increases in local values of nonuniformly incident fields produce relatively small increases in induced electric fields. This finding may be important in dosimetric consideration of circumstances, such as use of electric blankets, in which fields of low average strength are accompanied by intense local fields. © 1992 Wiley‐Liss, Inc.
Development of chicken embryos following exposure to 60‐Hz magnetic fields with differing waveforms
Authors: Martin A. H. 
Published: February 2006

AbstractPrevious studies in my laboratory have revealed a reproducible and statistically significant increase in the number of malformations in live chicken embryos that had been exposed during the first 48 h of incubation to a pulsed magnetic field (unipolar pulses, 100‐pps, 1‐μT peak density). In marked contrast, no adverse effect was seen following similar exposure to 60‐Hz, bipolar, unipolar, or split‐sine waves at 3‐μT peak‐to‐peak. In the four experiments comprising the present study, differences in the numbers of malformations between control and experimental groups were not statistically significant. Field‐free incubation for an additional 72 h after exposure to a bipolar sine wave for 48 h resulted in an increase in normal live embryos in both control and treated groups. © 1992 Wiley‐Liss, Inc.