Bioelectromagnetics via MedWorm.com

Analyzing digital vector waveforms of 0-3000 Hz magnetic fields for health studies

Bioelectromagnetics — Tue, 09 Mar 2010 00:00:00 +0100

To improve the assessment of magnetic field exposures for occupational health studies, the Multiwave® System III (MW3) was developed to capture personal exposures to the three-dimensional magnetic field vector B(t) in the 0-3000 Hz band. To process hundreds of full-shift MW3 measurements from epidemiologic studies, new computer programs were developed to calculate the magnetic field's physical properties and its interaction with biological systems through various mechanisms (magnetic induction, radical pair interactions, ion resonance, etc.). For automated calculations in the frequency domain, the software uses new algorithms that remove artifacts in the magnetic field's Fourier transform due to electronic noise and the person's motion through perturbations in the geomagnetic field from s...

No effect of TETRA hand portable transmission signals on human cognitive function and symptoms

Bioelectromagnetics — Mon, 08 Mar 2010 00:00:00 +0100

In conclusion, we found no evidence that brief exposure to hand-held TETRA transmitters' affects human cognitive function or subjective symptoms. Bioelectromagnetics. © 2010 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Contactless passive diagnosis for brain intracranial applications: A study using dielectric matching materials

Bioelectromagnetics — Tue, 02 Mar 2010 00:00:00 +0100

A prototype system for passive intracranial monitoring using microwave radiometry is proposed. It comprises an ellipsoidal conductive wall cavity to achieve beamforming and focusing, in conjunction with sensitive multiband receivers for detection. The system has already shown the capability to provide temperature and/or conductivity variations in phantoms and biological tissue. In this article, a variant of the initially constructed modality is theoretically and experimentally investigated. Specifically, dielectric matching materials are used in an effort to improve the system's focusing attributes. The theoretical study investigates the effect of dielectric matching materials on the system's detection depth, whereas measurements with phantoms focus on the investigation of the system's det...

Theoretical evaluation of magnetoreception of power-frequency fields

Bioelectromagnetics — Tue, 02 Feb 2010 00:00:00 +0100

Several effects of power-frequency (50/60 Hz) magnetic fields (PF-MF) of weak intensity have been hypothesized in animals and humans. No valid mechanism, however, has been proposed for an interaction between PF-MF and biological tissues and living beings at intensities relevant to animal and human exposure. Here we proposed to consider PF-MF as disrupters of the natural magnetic signal. Under exposure to these fields, an oscillating field exists that results from the vectorial summation of both the PF-MF and the geomagnetic field. At a PF-MF intensity (rms) of 0.5 µT, the peak-to-peak amplitude of the axis and/or intensity variations of this resulting field exceeds the related discrimination threshold of magnetoreception (MR) in migrating animals. From our evaluation of the 50/60 Hz respo...

Effects of weak static magnetic fields on endothelial cells

Bioelectromagnetics — Fri, 29 Jan 2010 00:00:00 +0100

Pulsed electromagnetic fields (PEMFs) have been used extensively in bone fracture repairs and wound healing. It is accepted that the induced electric field is the dose metric. The mechanisms of interaction between weak magnetic fields and biological systems present more ambiguity than that of PEMFs since weak electric currents induced by PEMFs are believed to mediate the healing process, which are absent in magnetic fields. The present study examines the response of human umbilical vein endothelial cells to weak static magnetic fields. We investigated proliferation, viability, and the expression of functional parameters such as eNOS, NO, and also gene expression of VEGF under the influence of different doses of weak magnetic fields. Applications of weak magnetic fields in tissue engineerin...

Power variations of wireless communication systems

Bioelectromagnetics — Fri, 29 Jan 2010 00:00:00 +0100

The use of wireless digital communication devices like GSM, WCDMA, HSPA, DECT, and WiFi changes the exposure of electromagnetic waves toward the user. Concentrating on the power variations on a slow and fast time scale, these new systems are discussed. Experimental results for both uplink and downlink are included for a sample of systems. The spectrum of the power fluctuations is seen as a convenient and compact way of describing very complex system behavior. The results are of interest for scientific studies of epidemiology and biological effects, and for general electromagnetic compatibility (EMC) aspects. Bioelectromagnetics, 2010 © 2010 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Absence of corneal endothelium injury in non-human primates treated with and without ophthalmologic drugs and exposed to 2.8 GHz pulsed microwaves

Bioelectromagnetics — Thu, 28 Jan 2010 00:00:00 +0100

Microwave-induced corneal endothelial damage was reported to have a low threshold (2.6 W/kg), and vasoactive ophthalmologic medications lowered the threshold by a factor of 10-0.26 W/kg. In an attempt to confirm these observations, four adult male Rhesus monkeys (Macaca mulatta) under propofol anesthesia were exposed to pulsed microwaves in the far field of a 2.8 GHz signal (1.43 ± 0.06 µs pulse width, 34 Hz pulse repetition frequency, 13.0 mW/cm2 spatial and temporal average, and 464 W/cm2 spatial and temporal peak (291 W/cm2 square wave equivalent) power densities). Corneal-specific absorption rate was 5.07 W/kg (0.39 W/kg/mW/cm2). The exposure resulted in a 1.0-1.2 °C increase in eyelid temperature. In Experiment I, exposures were 4 h/day, 3 days/week for 3 weeks (nine exposures and ...

Pulsed electromagnetic fields accelerate wound healing in the skin of diabetic rats

Bioelectromagnetics — Fri, 15 Jan 2010 00:00:00 +0100

In this study, diabetes was induced in male Wistar rats via a single subcutaneous injection of 65 mg/kg streptozocin (freshly dissolved in sterile saline, 0.9%). One month after the induction of diabetes, a full-thickness dermal incision (35 mm length) was made on the right side of the paravertebral region. The wound was exposed to ELF PEMF (20 Hz, 4 ms, 8 mT) for 1 h per day. Wound healing was evaluated by measuring surface area, percentage of healing, duration of healing, and wound tensile strength. Obtained results showed that the duration of wound healing in diabetic rats in comparison with the control group was significantly increased. In contrast, the rate of healing in diabetic rats receiving PEMF was significantly greater than in the diabetic control group. The wound tensile streng...

Model study of time-dependent muscle response to pulsed electrical stimulation

Bioelectromagnetics — Fri, 15 Jan 2010 00:00:00 +0100

A systems-level model analysis of neuromuscular response to external electrical stimulation is presented. Action potential (AP) generation, dynamics of voltage-based calcium release at the motor endplates controlled by the arrival of APs, and muscle force production are all comprehensively included. Numerical predictions exhibit trends that are qualitatively similar to measurements of muscle response in rats from a burst of cortical stimulation and a nanosecond impulse. Modulation of neural membrane conductances (including possible electroporation) that alters the neural impulse generation frequency is hypothesized as a possible mechanism leading to observed changes in muscle force production. Other possibilities such as calcium release at nerve end endings also exist. It is also proposed ...

Radio frequency magnetic field effects on molecular dynamics and iron uptake in cage proteins

Bioelectromagnetics — Fri, 15 Jan 2010 00:00:00 +0100

The protein ferritin has a natural ferrihydrite nanoparticle that is superparamagnetic at room temperature. For native horse spleen ferritin, we measure the low field magnetic susceptibility of the nanoparticle as 2.2 × 10-6 m3 kg-1 and its Néel relaxation time at about 10-10 s. Superparamagnetic nanoparticles increase their internal energy when exposed to radio frequency magnetic fields due to the lag between magnetization and applied field. The energy is dissipated to the surrounding peptidic cage, altering the molecular dynamics and functioning of the protein. This leads to an increased population of low energy vibrational states under a magnetic field of 30 µT at 1 MHz, as measured via Raman spectroscopy. After 2 h of exposure, the proteins have a reduced iron intake rate of about 2...

Occupational exposure to electric and magnetic fields during work tasks at 110 kV substations in the Tampere region

Bioelectromagnetics — Fri, 15 Jan 2010 00:00:00 +0100

The occupational exposure to electric and magnetic fields during various work tasks at seven 110 kV substations in Finland's Tampere region was studied. The aim was to investigate if the action values (10 kV/m for the E-field and 500 µT for the B-field) of the EU Directive 2004/40/EC were exceeded. Electric and magnetic fields were measured during the following work tasks: (1) walking or operating devices on the ground; (2) working from a service platform; (3) working around the power transformer on the ground or using a ladder; and (4) changing a bulb from a man hoist. In work task 2 "working from a service platform" the measured electric field (maximum value 16.6 kV/m) exceeded 10 kV/m in three cases. In the future it is important to study if the limit value (10 mA/m2) of Directive 2004...

Radiofrequency exposure on fast patrol boats in the Royal Norwegian Navy - an approach to a dose assessment

Bioelectromagnetics — Thu, 07 Jan 2010 00:00:00 +0100

Epidemiological studies related to radiofrequency (RF) electromagnetic fields (EMF) have mainly used crude proxies for exposure, such as job titles, distance to, or use of different equipment emitting RF EMF. The Royal Norwegian Navy (RNoN) has measured RF field emitted from high-frequency antennas and radars on several spots where the crew would most likely be located aboard fast patrol boats (FPB). These boats are small, with short distance between the crew and the equipment emitting RF field. We have described the measured RF exposure aboard FPB and suggested different methods for calculations of total exposure and annual dose. Linear and spatial average in addition to percentage of ICNIRP and squared deviation of ICNIRP has been used. The methods will form the basis of a job exposure m...

Sinusoidal ELF magnetic fields affect acetylcholinesterase activity in cerebellum synaptosomal membranes

Bioelectromagnetics — Wed, 30 Dec 2009 00:00:00 +0100

The effects of extremely low frequency magnetic fields (ELF-MF) on acetylcholinesterase (AChE) activity of synaptosomal membranes were investigated. Sinusoidal fields with 50 Hz frequency and different amplitudes caused AChE activity to decrease about 27% with a threshold of about 0.74 mT. The decrease in enzymatic activity was independent of the time of permanence in the field and was completely reversible. Identical results were obtained with exposure to static MF of the same amplitudes. Moreover, the inhibitory effects on enzymatic activity are spread over frequency windows with different maximal values at 60, 200, 350, and 475 Hz. When synaptosomal membranes were solubilized with Triton, ELF-MF did not affect AChE activity, suggesting the crucial role of the membrane, as well as the li...

EMF acts on rat bone marrow mesenchymal stem cells to promote differentiation to osteoblasts and to inhibit differentiation to adipocytes

Bioelectromagnetics — Tue, 29 Dec 2009 00:00:00 +0100

The use of electromagnetic fields (EMFs) to treat nonunion fractures developed from observations in the mid-1900s. Whether EMF directly regulates the bone marrow mesenchymal stem cells (MSCs), differentiating into osteoblasts or adipocytes, remains unknown. In the present study, we investigated the roles of sinusoidal EMF of 15 Hz, 1 mT in differentiation along these separate lineages using rat bone marrow MSCs. Our results showed that EMF promoted osteogenic differentiation of the stem cells and concurrently inhibited adipocyte formation. EMF increased alkaline phosphatase (ALP) activity and mineralized nodule formation, and stimulated osteoblast-specific mRNA expression of RUNX2, ALP, BMP2, DLX5, and BSP. In contrast, EMF decreased adipogenesis and inhibited adipocyte-specific mRNA expre...

Estimation of whole-body SAR from electromagnetic fields using personal exposure meters

Bioelectromagnetics — Tue, 29 Dec 2009 00:00:00 +0100

In this article, personal electromagnetic field measurements are converted into whole-body specific absorption rates for exposure of the general public. Whole-body SAR values calculated from personal exposure meter data are compared for different human spheroid phantoms: the highest SAR values (at 950 MHz) are obtained for the 1-year-old child (99th percentile of 17.9 µW/kg for electric field strength of 0.36 V/m), followed by the 5-year-old child, 10-year-old child, average woman, and average man. For the 1-year-old child, whole-body SAR values due to 9 different radiofrequency sources (FM, DAB, TETRA, TV, GSM900 DL, GSM1800 DL, DECT, UMTS DL, WiFi) are determined for 15 different scenarios. An SAR matrix for 15 different exposure scenarios and 9 sources is provided with the personal fie...

Comments on "extremely low frequency electric fields and cancer: Assessing the evidence" by Kheifets et al.

Bioelectromagnetics — Tue, 08 Dec 2009 00:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

The role of the calmodulin-dependent pathway in static magnetic field-induced mechanotransduction

Bioelectromagnetics — Wed, 02 Dec 2009 00:00:00 +0100

While the effects of static magnetic fields (SMFs) on osteoblastic differentiation are well demonstrated, the mechanotransduction pathways of SMFs are still unclear. The aim of this study was to explore the role of calmodulin in the biophysical effects of SMFs on osteoblastic cells. MG63 cells were exposed to a 0.4 T SMF. The expression of phosphodiesterase RNA in the cytoplasm was tested using real-time polymerase chain reaction. The differentiation of the cells was assessed by detecting changes in alkaline phosphatase activity. The role of calmodulin antagonist W-7 was used to evaluate alterations in osteoblastic proliferation and differentiation after the SMF simulations. Our results showed that SMF exposure increased alkaline phosphatase activity and phosphodiesterase 1C gene expressio...

Effect of exposure to 50 Hz magnetic field with or without insulin on blood-brain barrier permeability in streptozotocin-induced diabetic rats

Bioelectromagnetics — Tue, 01 Dec 2009 00:00:00 +0100

We investigated the effect of long-term exposure to modulation magnetic field (MF), insulin, and their combination on blood-brain barrier (BBB) permeability in a diabetic rat model. Fifty-three rats were randomly assigned to one of six groups: sham, exposed to no MF; MF, exposed to MF; diabetes mellitus (DM), DM induced with streptozotocin (STZ); DM plus MF (DMMF); DM plus insulin therapy (DMI); and DM plus insulin therapy plus MF (DMIMF). All the rats underwent Evans blue (EB) measurement to evaluate the BBB 30 days after the beginning of experiments. The rats in MF, DMMF, and DMIMF groups were exposed to MF (B = 5 mT) for 165 min every day for 30 days. Mean arterial blood pressure (MABP), body mass, and serum glucose level of the study rats were recorded. The extravasation of brain EB of...

Corrections to "spatial gradient effects of 120 mT static magnetic field on endothelial tubular formation in vitro"

Bioelectromagnetics — Sat, 31 Oct 2009 00:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Signal transduction of the melatonin receptor MT1 is disrupted in breast cancer cells by electromagnetic fields

Bioelectromagnetics — Fri, 30 Oct 2009 00:00:00 +0100

In this study we investigated the impact of EMFs on the signal transduction of the high-affinity receptor MT1 in parental MCF-7 cells and MCF-7 cells transfected with the MT1 gene. The binding of the cAMP-responsive element binding (CREB) protein to a promoter sequence of BRCA-1 after stimulation with melatonin was analyzed by a gel-shift assay and the expression of four estrogen-responsive genes was measured in sham-exposed breast cancer cells and cells exposed to a sinusoidal 50 Hz EMF of 1.2 µT for 48 h. In sham-exposed cells, binding of CREB to the promoter of BRCA-1 was increased by estradiol and subsequently diminished by treatment with melatonin. In cells exposed to 1.2 µT, 50 Hz EMF, binding of CREB was almost completely omitted. Expression of BRCA-1, p53, p21WAF, and c-myc was i...

Pulsed electromagnetic fields accelerate proliferation and osteogenic gene expression in human bone marrow mesenchymal stem cells during osteogenic differentiation

Bioelectromagnetics — Thu, 29 Oct 2009 00:00:00 +0100

In this study, we examined the effect of pulsed electromagnetic fields (PEMFs) on cell proliferation, alkaline phosphatase (ALP) activity, mineralization of the extracellular matrix, and gene expression in bone marrow mesenchymal stem cells (BMMSCs) during osteogenic differentiation. Exposure of BMMSCs to PEMFs increased cell proliferation by 29.6% compared to untreated cells at day 1 of differentiation. Semi-quantitative RT-PCR indicated that PEMFs significantly altered temporal expression of osteogenesis-related genes, including a 2.7-fold increase in expression of the key osteogenesis regulatory gene cbfa1, compared to untreated controls. In addition, exposure to PEMFs significantly increased ALP expression during the early stages of osteogenesis and substantially enhanced mineralizatio...

A model for radiofrequency electromagnetic field predictions at outdoor and indoor locations in the context of epidemiological research

Bioelectromagnetics — Thu, 15 Oct 2009 23:00:00 +0100

We present a geospatial model to predict the radiofrequency electromagnetic field from fixed site transmitters for use in epidemiological exposure assessment. The proposed model extends an existing model toward the prediction of indoor exposure, that is, at the homes of potential study participants. The model is based on accurate operation parameters of all stationary transmitters of mobile communication base stations, and radio broadcast and television transmitters for an extended urban and suburban region in the Basel area (Switzerland). The model was evaluated by calculating Spearman rank correlations and weighted Cohen's kappa ([kappa]) statistics between the model predictions and measurements obtained at street level, in the homes of volunteers, and in front of the windows of these ho...

Static magnetic field exposure fails to affect the viability of different bacteria strains

Bioelectromagnetics — Fri, 09 Oct 2009 23:00:00 +0100

The viability of the microbes Saccharomyces cerevisiae, Bacillus circulans, Escherichia coli, Micrococcus luteus, Pseudomonas fluorescens, Salmonella enteritidis, Serratia marcescens, and Staphylococcus aureus was tested under static magnetic field exposure up to 24 h in either a homogeneous (159.2 ± 13.4 mT) or three types of inhomogeneous static magnetic fields: (i) peak-to-peak magnetic flux density 476.7 ± 0.1 mT with a lateral magnetic flux density gradient of 47.7 T/m, (ii) 12.0 ± 0.1 mT with 1.2 T/m, or (iii) 2.8 ± 0.1 mT with 0.3 T/m. Even the longest period of exposure failed to produce any effect in the growth of bacteriae that could be correlated with static magnetic field exposure. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Effects of pulsed magnetic field on the formation of magnetosomes in the Magnetospirillum sp. strain AMB-1

Bioelectromagnetics — Thu, 24 Sep 2009 23:00:00 +0100

In this study, a 50 Hz, 2 mT pulsed magnetic field (PMF) was applied to study the effects on the formation of magnetosomes in Magnetospirillum sp. strain AMB-1. The results showed that the cellular magnetism (Rmag) of AMB-1 culture significantly increased while the growth of cells remained unaffected after exposure. The number of magnetic particles per cell was enhanced by about 15% and slightly increased ratios of magnetic particles of superparamagnetic property (size 50 nm) were observed after exposure to PMF. In addition, the intracellular iron accumulation slightly increased after PMF exposure. Therefore, it was concluded that 50 Hz, 2 mT PMF enhances the formation of magnetosomes in Magnetospirillum sp. strain AMB-1. Our results suggested that lower strength of PMF has no significant ...

Survey of electromagnetic field exposure in bedrooms of residences in lower Austria

Bioelectromagnetics — Wed, 23 Sep 2009 23:00:00 +0100

We report results from spot measurements at the bedside that comprise electrostatic fields, extremely low-frequency electric fields (ELF-EFs), extremely low-frequency magnetic fields (ELF-MFs), and RF-EMFs. Measurements were taken in 226 households throughout Lower Austria. In addition, effects of simple reduction measures (e.g., removal of clock radios or increasing their distance from the bed, turning off Digital Enhanced Cordless Telecommunication (DECT) telephone base stations) were assessed. All measurements were well below International Commission on Non-Ionizing Radiation Protection (ICNIRP) guideline levels. Average night-time ELF-MFs (long-term measurement from 10 pm to 6 am, geometric mean over households) above 100 nT were obtained in 2.3%, and RF-EMFs above 1000 µW/m2 in 7.1% ...

Millimeter wave effects on electrical responses of the sural nerve in vivo

Bioelectromagnetics — Sun, 20 Sep 2009 23:00:00 +0100

Millimeter wave (MMW, 42.25 GHz)-induced changes in electrical activity of the murine sural nerve were studied in vivo using external electrode recordings. MMW were applied to the receptive field of the sural nerve in the hind paw. We found two types of responses of the sural nerve to MMW exposure. First, MMW exposure at the incident power density [ge]45 mW/cm2 inhibited the spontaneous electrical activity. Exposure with lower intensities (10-30 mW/cm2) produced no detectable changes in the firing rate. Second, the nerve responded to the cessation of MMW exposure with a transient increase in the firing rate. The effect lasted 20-40 s. The threshold intensity for this effect was 160 mW/cm2. Radiant heat exposure reproduced only the inhibitory effect of MMW but not the transient excitatory r...

No effects of mobile phone use on cortical auditory change-detection in children: An ERP study

Bioelectromagnetics — Sun, 20 Sep 2009 23:00:00 +0100

We investigated the effect of mobile phone use on the auditory sensory memory in children. Auditory event-related potentials (ERPs), P1, N2, mismatch negativity (MMN), and P3a, were recorded from 17 children, aged 11-12 years, in the recently developed multi-feature paradigm. This paradigm allows one to determine the neural change-detection profile consisting of several different types of acoustic changes. During the recording, an ordinary GSM (Global System for Mobile Communications) mobile phone emitting 902 MHz (pulsed at 217 Hz) electromagnetic field (EMF) was placed on the ear, over the left or right temporal area (SAR1g = 1.14 W/kg, SAR10g = 0.82 W/kg, peak value = 1.21 W/kg). The EMF was either on or off in a single-blind manner. We found that a short exposure (two 6 min blocks for ...

Comparing performances of logistic regression and neural networks for predicting melatonin excretion patterns in the rat exposed to ELF magnetic fields

Bioelectromagnetics — Sun, 20 Sep 2009 23:00:00 +0100

In conclusion, analysis of the bioelectromagnetic data could result in finding a relationship between electromagnetic fields and different biological processes. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Development of a higher power intermediate-frequency magnetic field exposure system for in vitro studies

Bioelectromagnetics — Wed, 16 Sep 2009 23:00:00 +0100

Effects of extremely low-frequency magnetic field exposure on cognitive functions: results of a meta-analysis

Bioelectromagnetics — Mon, 14 Sep 2009 23:00:00 +0100

There is extensive literature on possible effects of extremely low-frequency magnetic fields (ELF-MFs) on human cognitive functions. However, due to methodological deficits (e.g., low statistical power, small sample sizes) findings have been inconsistent. In the current study we try to overcome these problems by carrying out a meta-analysis. Literature research revealed 17 studies. Nine of these were included in the meta-analysis because they fulfilled minimum requirements (e.g., at least single-blind experimental study design and documentation of means and standard deviation of the dependent variables). All of the studies used a 50 Hz magnetic field exposure. Small but significant effect sizes could be detected in two cognitive dimensions: in the hard level of visual duration discriminati...

Awarding of 2008 Most Influential Bioelectromagnetics Journal Paper by Citation Awards

Bioelectromagnetics — Sun, 13 Sep 2009 23:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Modification of pulse sequences reduces occupational exposure from MRI switched gradient fields: Preliminary results

Bioelectromagnetics — Sun, 13 Sep 2009 23:00:00 +0100

The gradient fields in magnetic resonance imaging (MRI) will in some circumstances exceed the ICNIRP guidelines of occupational electromagnetic field exposure when personnel are near the scanner during MRI scanning. In this work we have shown that using commercially available modified sequences for noise reduction purposes, exposure will decrease by a factor of 1.5 with preserved image quality. This is a first step toward optimizing occupational exposure within the scanner room without affecting image quality. Bioelectromagnetics, 2009. © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Effects of prenatal exposure to a 50-Hz magnetic field on one-trial passive avoidance learning in 1-day-old chicks

Bioelectromagnetics — Tue, 08 Sep 2009 23:00:00 +0100

We investigated memory impairment in newly hatched chicks following in ovo exposure to a 50-Hz magnetic field (MF) of 2 mT (60 min/day) on embryonic days 12-18. Isolated and paired chicks were used to test the effect of stress during training, and memory retention was tested at 10, 30, and 120 min, following exposure to a bitter-tasting bead (100% methylanthranilate). Results showed that memory was intact at 10 min in both isolated and paired chicks with or without MF exposure. However, while isolated chicks had good memory retention levels at 30 and 120 min, those exposed to MF did not. The results suggest a potential disruption of memory formation following in ovo exposure to MF, with this effect only evident in the more stressed, isolated chicks. Bioelectromagnetics, 2009. © 2009 Wiley...

Electromagnetic and thermal evaluation of an applicator specialized to permit high-resolution non-perturbing optical evaluation of cells being irradiated in the W-band

Bioelectromagnetics — Thu, 03 Sep 2009 23:00:00 +0100

To permit epi-illuminated, high-resolution optical microscopy of cells in monolayer culture during unperturbed W-band (75-110 GHz) irradiation, a new class of applicator has been developed based upon WR10 rectangular waveguide components: the cells are normally plated onto the underside of a coverslip which is then placed against the under side of a waveguide flange and receives a roughly circular exposure pattern, with the ±1 dB central spot roughly 1 mm in diameter. Constructed and tested with 94 GHz millimeter waves, water-immersion optics, and free-convection cooling, the applicator works robustly and permits SARs at the cell layer as high as 4500 W/kg before the steady-state temperature rise at the cell layer exceeds 0.5 K. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: ...

Lack of a co-promotion effect of 60 Hz circularly polarized magnetic fields on spontaneous development of lymphoma in AKR mice

Bioelectromagnetics — Sun, 30 Aug 2009 23:00:00 +0100

In conclusion, there was no evidence that exposure to 60 Hz circularly polarized MF strengths up to 500 µT promoted lymphoma in AKR mice. Bioelectromagnetics, 2009. © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Exposure of non-target tissues in medical diathermy

Bioelectromagnetics — Wed, 26 Aug 2009 23:00:00 +0100

With different prevalence in different regions, radio frequency (RF) electromagnetic fields (EMF) are widely used for therapeutic tissue heating. Although short-wave diathermy (27.12 MHz) is the most popular treatment modality, quantitative data on patient's exposure have been lacking. By numerical simulation with the numerical anatomical model NORMAN, intracorporal distributions of specific absorption rates (SAR) were investigated for different treatment scenarios and applicators. Quantitative data are provided for exposures of target treatment areas as well as for vulnerable regions such as the eye lenses, central nervous system, and testes. Different applicators and distances were investigated. Capacitive and inductive applicators exhibit quite a different heating efficiency. It could b...

Idiopathic environmental intolerance attributed to electromagnetic fields (formerly 'electromagnetic hypersensitivity'): An updated systematic review of provocation studies

Bioelectromagnetics — Thu, 13 Aug 2009 23:00:00 +0100

Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF; formerly 'electromagetic hypersensitivity') is a medically unexplained illness in which subjective symptoms are reported following exposure to electrical devices. In an earlier systematic review, we reported data from 31 blind provocation studies which had exposed IEI-EMF volunteers to active or sham electromagnetic fields and assessed whether volunteers could detect these fields or whether they reported worse symptoms when exposed to them. In this article, we report an update to that review. An extensive literature search identified 15 new experiments. Including studies reported in our earlier review, 46 blind or double-blind provocation studies in all, involving 1175 IEI-EMF volunteers, have tested whethe...

Acceleration of germination and early growth of wheat and bean seedlings grown under various magnetic field and osmotic conditions

Bioelectromagnetics — Wed, 12 Aug 2009 23:00:00 +0100

This study reports the effects of different intensities of static MF (4 or 7 mT) on seed germination and seedling growth of bean or wheat seeds in different media having 0, 2, 6, and 10 atmosphere (atm) osmotic pressure prepared with sucrose or salt. The germination percentages of the treated seeds were compared with untreated seeds germinated in different osmotic pressure during 7 days of incubation. The application of both MFs promoted the germination ratios of bean and wheat seeds, regardless of increasing osmotic pressure of sucrose or salt. Growth data measured on the 7th day showed that the treated plants grew faster than control. After 7 days of incubation, the mean length of treated seedlings was statistically higher than control plants in all the media. The greatest germination an...

Pulsed electromagnetic fields stimulation affects BMD and local factor production of rats with disuse osteoporosis

Bioelectromagnetics — Mon, 10 Aug 2009 23:00:00 +0100

Pulsed electromagnetic fields (PEMF) have been used widely to treat nonunion fractures and related problems in bone healing, as a biological and physical method. With the use of Helmholtz coils and PEMF stimulators to generate uniform time-varying electromagnetic fields, the effects of extremely low frequency electromagnetic fields on bone mineral density (BMD) and local factor production in disuse osteoporosis (DOP) rats were investigated. Eighty 4-month-old female Sprague Dawley (SD) rats were randomly divided into intact (INT) group, DOP group, calcitonin-treated (CT) group, and PEMF stimulation group. The right hindlimbs of all the rats were immobilized by tibia-tail fixation except for those rats in the INT group. Rats in the CT group were injected with calcitonin (2 IU/kg, i.p., once...

Extremely low frequency electric fields and cancer: Assessing the evidence

Bioelectromagnetics — Fri, 31 Jul 2009 23:00:00 +0100

Much of the research and reviews on extremely low frequency (ELF) electric and magnetic fields (EMFs) have focused on magnetic rather than electric fields. Some have considered such focus to be inappropriate and have argued that electric fields should be part of both epidemiologic and laboratory work. This paper fills the gap by systematically and critically reviewing electric-fields literature and by comparing overall strength of evidence for electric versus magnetic fields. The review of possible mechanisms does not provide any specific basis for focusing on electric fields. While laboratory studies of electric fields are few, they do not indicate that electric fields should be the exposure of interest. The existing epidemiology on residential electric-field exposures and appliance use d...

1950 MHz IMT-2000 field does not activate microglial cells in vitro

Bioelectromagnetics — Thu, 30 Jul 2009 23:00:00 +0100

Given the widespread use of the cellular phone today, investigation of potential biological effects of radiofrequency (RF) fields has become increasingly important. In particular, much research has been conducted on RF effects on brain function. To examine any biological effects on the central nervous system (CNS) induced by 1950 MHz modulation signals, which are controlled by the International Mobile Telecommunication-2000 (IMT-2000) cellular system, we investigated the effect of RF fields on microglial cells in the brain. We assessed functional changes in microglial cells by examining changes in immune reaction-related molecule expression and cytokine production after exposure to a 1950 MHz Wideband Code Division Multiple Access (W-CDMA) RF field, at specific absorption rates (SARs) of 0...

Mobile telephone use is associated with changes in cognitive function in young adolescents

Bioelectromagnetics — Thu, 30 Jul 2009 23:00:00 +0100

As part of the Mobile Radiofrequency Phone Exposed Users' Study (MoRPhEUS), a cross-sectional epidemiological study examined cognitive function in secondary school students. We recruited 317, 7th grade students (144 boys, 173 girls, median age 13 years) from 20 schools around Melbourne, Australia. Participants completed an exposure questionnaire based on the Interphone study, a computerised cognitive test battery, and the Stroop colour-word test. The principal exposure metric was the total number of reported mobile phone voice calls per week. Linear regression models were fitted to cognitive test response times and accuracies. Age, gender, ethnicity, socio-economic status and handedness were fitted as covariates and standard errors were adjusted for clustering by school. The accuracy of wo...

Extremely low frequency pulsed electromagnetic field designed for antinociception does not affect microvascular responsiveness to the vasodilator acetylcholine

Bioelectromagnetics — Wed, 29 Jul 2009 23:00:00 +0100

A 225 µT, extremely low frequency, pulsed electromagnetic field (PEMF) that was designed for the induction of antinociception, was tested for its effectiveness to influence blood flow within the skeletal microvasculature of a male Sprague-Dawley rat model (n = 103). Acetylcholine (0.1, 1.0, or 10 mM) was used to perturb normal blood flow and to delineate differential effects of the PEMF, based on degree of vessel dilation. After both 30 and 60 min of PEMF exposure, we report no effects on peak perfusion response to acetylcholine (with only 0.2% of the group difference attributed to exposure). Spectral analysis of blood flow data was generated to obtain information related to myogenic activity (0.15-0.40 Hz), respiratory rate (0.4-2.0 Hz), and heart rate (2.0-7.0 Hz), including the peak fr...

Response to Comment on Vali[ccaron] et al., 2009

Bioelectromagnetics — Sun, 26 Jul 2009 23:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Effects of extremely low-frequency magnetic fields on the oviposition of Drosophila melanogaster over three generations

Bioelectromagnetics — Thu, 23 Jul 2009 23:00:00 +0100

The aim of this study was to determine the effects of an extremely low-frequency 50 Hz magnetic field (ELFMF) on the oviposition and development of Drosophila melanogaster. The results show that exposure of D. melanogaster females of generation P and all the development stages of generation F1 to an ELFMF weakened the oviposition of these insects in their subsequent generations. Bioelectromagnetics, 2009. © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

A biofilm growth protocol and the design of a magnetic field exposure setup to be used in the study of magnetic fields as a means of controlling bacterial biofilms

Bioelectromagnetics — Wed, 22 Jul 2009 23:00:00 +0100

No effects of mobile phone electromagnetic field on auditory brainstem response

Bioelectromagnetics — Thu, 16 Jul 2009 23:00:00 +0100

The present study investigated the possible effects of the electromagnetic field (EMF) emitted by an ordinary GSM mobile phone (902.4 MHz pulsed at 217 Hz) on brainstem auditory processing. Auditory brainstem responses (ABR) were recorded in 17 healthy young adults, without a mobile phone at baseline, and then with a mobile phone on the ear under EMF-off and EMF-on conditions. The amplitudes, latencies, and interwave intervals of the main ABR components (waves I, III, V) were compared among the three conditions. ABR waveforms showed no significant differences due to exposure, suggesting that short-term exposure to mobile phone EMF did not affect the transmission of sensory stimuli from the cochlea up to the midbrain along the auditory nerve and brainstem auditory pathways. Bioelectromagnet...

Comment on Vali[ccaron] et al., 2009

Bioelectromagnetics — Tue, 14 Jul 2009 23:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Exposure to high static or pulsed magnetic fields does not affect cellular processes in the yeast Saccharomyces cerevisiae

Bioelectromagnetics — Mon, 13 Jul 2009 23:00:00 +0100

We report results of a study of the effects of strong static (up to 16 T for 8 h) and pulsed (up to 55 T single-shot and 4 × 20 T repeated shots) magnetic fields on Saccharomyces cerevisiae cultures in the exponential phase of growth. In contrast to previous reports restricted to only a limited number of cellular parameters, we have examined a wide variety of cellular processes: genome-scale gene expression, proteome profile, cell viability, morphology, and growth, metabolic and fermentation activity after magnetic field exposure. None of these cellular activities were impaired in response to static or pulsed magnetic field exposure. Our results confirm and extend previous reports on the absence of magnetic field effects on yeast and support the hypothesis that magnetic fields have no imp...

The association between socioeconomic status and exposure to mobile telecommunication networks in children and adolescents

Bioelectromagnetics — Sun, 12 Jul 2009 23:00:00 +0100

A potential association between socioeconomic status (SES) and self-reported use of mobile phones has been investigated in a few studies. If measured exposure to mobile phone networks differs by SES in children, it has not yet been studied. Interview data of 1,481 children and 1,505 adolescents on participants' mobile phone use, socio-demographic characteristics and potential confounders were taken from the German MobilEe-study. Sociodemographic data was used to stratify participants into three "status groups" (low, middle, high). Using a personal dosimeter, we obtained an exposure profile over 24 h for each of the participants. Exposure levels during waking hours were expressed as mean percentage of the reference level. Children with a low SES were more likely to own a mobile phone (OR 2....

Neurobiological effects of pulsed magnetic field on diabetes-induced neuropathy

Bioelectromagnetics — Fri, 10 Jul 2009 23:00:00 +0100

In this study, the effects of PMF treatment were investigated in Streptozotocin (STZ)-induced acute and chronic diabetic rats by measuring the thermal latencies, mechanical thresholds, whole blood glucose levels and body weights. After STZ administration to rats, blood glucose level elevated and body weight decreased. Although PMF treatment did not affect changes in body weight, the blood glucose levels of PMF-treated diabetic rats exhibited a decrease during the treatments. Diabetic animals displayed marked decrease in mechanical thresholds and thermal latencies. While treatment of PMF partially restored the mechanical thresholds and thermal latency in acute diabetic rats, PMF caused a corrective effect on only mechanical threshold of chronic diabetic rats. These results suggested that tr...

Cytoskeletal forces produced by extremely low-frequency electric fields acting on extracellular glycoproteins

Bioelectromagnetics — Thu, 09 Jul 2009 23:00:00 +0100

This article establishes for the first time a direct, quantitative model that links the field to cytoskeletal forces. In a previous article, applied electric fields of physiological strength were shown to produce significant mechanical torques at the cellular level. In this article, the corresponding forces exerted on the cytoskeleton are computed and found to be comparable in magnitude to mechanical forces known to produce physiological effects. In addition to the electrical force, the viscous drag force exerted by the surrounding medium and the restoring force exerted by the neighboring structures are considered in the analysis. For an applied electric field of 10 V/m, the force transmitted to the CD44 receptor of a hyaluronan chain in cartilage is about 1 pN at 10 Hz and 7 pN at 1 Hz. F...

Behavioral change related to Wenchuan devastating earthquake in mice

Bioelectromagnetics — Sat, 04 Jul 2009 23:00:00 +0100

It has been suggested that some animals are much more capable of perceiving certain kinds of geophysical stimuli which may precede earthquakes than humans, but the anecdotal phenomena or stories about unusual animal behaviors prior to an earthquake should be interpreted with objective data. During the Wenchuan magnitude 8.0 earthquake that happened in Wenchuan county (31.0° north latitude, 103.4° east longitude) of Sichuan province, China, on May 12, 2008, eight mice were monitored for locomotor activity and circadian rhythm in constant darkness with temperature 22-24 °C and humidity 55-65% for 38 days. The ongoing monitoring of locomotor activity of mice in our laboratory made it possible to design a posteriori study investigating whether the earthquake was associated with any change i...

Changes in synaptic efficacy and seizure susceptibility in rat brain slices following extremely low-frequency electromagnetic field exposure

Bioelectromagnetics — Tue, 30 Jun 2009 23:00:00 +0100

The effects of electromagnetic fields (EMFs) on living organisms are recently a focus of scientific interest, as they may influence everyday life in several ways. Although the neural effects of EMFs have been subject to a considerable number of investigations, the results are difficult to compare since dissimilar exposure protocols have been applied on different preparations or animals. In the present series of experiments, whole rats or excised rat brain slices were exposed to a reference level-intensity (250-500 µT, 50 Hz) EMF in order to examine the effects on the synaptic efficacy in the central nervous system. Electrophysiological investigation was carried out ex vivo, on neocortical and hippocampal slices; basic synaptic functions, short- and long-term plasticity and seizure suscept...

The relation between the specific absorption rate and electromagnetic field intensity for heterogeneous exposure conditions at mobile communications frequencies

Bioelectromagnetics — Wed, 24 Jun 2009 23:00:00 +0100

The relation between the incident electromagnetic field strength and both the whole-body and the local specific absorption rate (SAR) was investigated for typical heterogeneous exposure scenarios for frequencies relevant for mobile communication. The results were compared to results from plane wave exposure. Heterogeneous exposure arises from multiple path propagation of the electromagnetic waves to the location of interest. It is shown that plane wave exposure does not represent worst-case exposure conditions. When the electric field strength arising at plane wave exposure is compared to the electric field strength averaged over the volume of the human body occurring during multipath exposure, 12% of all heterogeneous cases examined represent worse exposure conditions than plane wave expo...

Hypersensitivity to RF fields emitted from CDMA cellular phones: A provocation study

Bioelectromagnetics — Mon, 22 Jun 2009 23:00:00 +0100

In conclusion, RF exposure did not have any effects on physiological parameters or subjective symptoms in either group. As for EMF perception, there was no evidence that the EHS group better perceived EMF than the non-EHS group. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

The influence of pulsed magnetic fields (PMFs) on nonsynaptic potentials recorded from the central and peripheral nervous systems in vitro

Bioelectromagnetics — Mon, 22 Jun 2009 23:00:00 +0100

The influence of pulsed magnetic fields (PMFs) on nonsynaptic potentials recorded from the central and peripheral nervous system in vitro has been investigated. The population spikes (PSs) recorded from hippocampal slices during antidromic stimulation and compound action potentials (CAPs) recorded from the segments of the sciatic nerve were used as indicators of neuronal activity. The potentials recorded from both preparations were significantly and permanently enhanced following PMF (0.16 Hz, 15 mT) exposure. The increase in the antidromic PS occurred even in the presence of potassium channel blocker tetraethylammonium (TEA) and was accompanied by multiple spiking. Among all frequencies of PMF tested (0.5, 0.16, 0.07, 0.03, 0.0 Hz), the frequency of 0.5 Hz was the most effective in enhanc...

Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans

Bioelectromagnetics — Wed, 17 Jun 2009 04:00:00 +0100

This study used a microwave exposure system (1.0 GHz, 0.5 W power input; SAR 0.9-3 mW kg-1 for 6-well plates) that minimises temperature differentials between sham and exposed conditions ([le]0.1 °C). Parallel measurement and simulation studies of SAR distribution within this exposure system are presented. We compared five Affymetrix gene arrays of pooled triplicate RNA populations from sham-exposed L4/adult worms against five gene arrays of pooled RNA from microwave-exposed worms (taken from the same source population in each run). No genes showed consistent expression changes across all five comparisons, and all expression changes appeared modest after normalisation ([le]40% up- or down-regulated). The number of statistically significant differences in gene expression (846) was less tha...

Application of a temperature-dependent fluorescent dye (Rhodamine B) to the measurement of radiofrequency radiation-induced temperature changes in biological samples

Bioelectromagnetics — Tue, 09 Jun 2009 04:00:00 +0100

We have applied a non-contact method for studying the temperature changes produced by radiofrequency (RF) radiation specifically to small biological samples. A temperature-dependent fluorescent dye, Rhodamine B, as imaged by laser scanning confocal microscopy (LSCM) was used to do this. The results were calibrated against real-time temperature measurements from fiber optic probes, with a calibration factor of 3.4% intensity change °C-1 and a reproducibility of ±6%. This non-contact method provided two-dimensional and three-dimensional images of temperature change and distributions in biological samples, at a spatial resolution of a few micrometers and with an estimated absolute precision of around 1.5 °C, with a differential precision of 0.4 °C. Temperature rise within tissue was found...

Enhancement of the hydrolysis activity of F0F1-ATPases using 60 Hz magnetic fields

Bioelectromagnetics — Fri, 05 Jun 2009 04:00:00 +0100

The effects of extremely low frequency (ELF) magnetic fields on membrane F0F1-ATPase activity have been studied. When the F0F1-ATPase was exposed to 60 Hz magnetic fields of different magnetic intensities, 0.3 and 0.5 mT magnetic fields enhanced the hydrolysis activity, whereas 0.1 mT exposure caused no significant changes. Even if the F0F1-ATPase was inhibited by N,N-dicyclohexylcarbodiimide, its hydrolysis activity was enhanced by a 0.5 mT 60 Hz magnetic field. Moreover, when the chromatophores which were labeled with F-DHPE were exposed to a 0.5 mT, 60 Hz magnetic field, it was found that the pH of the outer membrane of the chromatophore was unchanged, which suggested that the magnetic fields used in this work did not affect the activity of F0. Taken together, our results show that the ...

Lack of chick embryotoxicity after 20 kHz, 1.1 mT magnetic field exposure

Bioelectromagnetics — Wed, 03 Jun 2009 04:00:00 +0100

This investigation was undertaken because biological studies to evaluate the effects of intermediate frequency magnetic fields are insufficient. White Leghorn fertile eggs (60/group) were either exposed to a 20 kHz, 1.1 mT(rms) sinusoidal magnetic field or sham-exposed during the first 2, 7, or 11 days of embryogenesis. Lower dose exposures at 0.011 and 0.11 mT(rms) for 2 days were also conducted to elucidate possible dose-response relationships. Additional eggs given all-trans-retinoic acid, a teratogen, were exposed to the 1.1 mT(rms) magnetic field for the same periods to investigate the modification of embryotoxicity. After exposure, embryos were examined for mortality and developmental abnormalities. Developmental stage, number of somite pairs, and other developmental endpoints were a...

Effect of radiofrequency electromagnetic field exposure on in vitro models of neurodegenerative disease

Bioelectromagnetics — Sat, 30 May 2009 04:00:00 +0100

In this work we tested viability, proliferation, and vulnerability of neural cells, after continuous radiofrequency (RF) electromagnetic fields exposure (global system for mobile telecommunications (GSM) modulated 900 MHz signal at a specific absorption rate (SAR) of 1 W/kg and maximum duration 144 h) generated by transverse electromagnetic cells. We used two cellular systems, SN56 cholinergic for example, SN56 cholinergic cell line and rat primary cortical neurons, and well-known neurotoxic challenges, such as glutamate, 25-35AA beta-amyloid, and hydrogen peroxide. Exposure to RF did not change viability/proliferation rate of the SN56 cholinergic cells or viability of cortical neurons. Co-exposure to RF exacerbated neurotoxic effect of hydrogen peroxide in SN56, but not in primary cortica...

Electromagnetic fields and epidemiology: An overview inspired by the fourth course at the International School of Bioelectromagnetics

Bioelectromagnetics — Thu, 28 May 2009 04:00:00 +0100

The role of the concentration and distribution of water in the complex permittivity of breast fat tissue

Bioelectromagnetics — Thu, 28 May 2009 04:00:00 +0100

The structure of breast tissue is complicated and highly variable and presents a great challenge in the development of physical models that may be used to obtain its effective complex permittivity. Empirical models are commonly used by researchers to fit measured data and extrapolated to higher frequencies. However, these models have not been verified experimentally at higher frequencies. Theoretical models of tissue permittivity to explain the role of water are not available today. This communication is a systematic study of several models to estimate the complex permittivity of breast fat tissue based on volume content and distribution of water in the tissue. These models are implemented in (i) long wavelength, sparse concentration limit; (ii) full wave finite element simulation; and (ii...

Reactive oxygen species formation is not enhanced by exposure to UMTS 1950 MHz radiation and co-exposure to ferrous ions in Jurkat cells

Bioelectromagnetics — Wed, 27 May 2009 04:00:00 +0100

This study was designed to assess if radiofrequency (RF) radiation induces oxidative stress in cultured mammalian cells when given alone or in combination with ferrous ions (FeSO4). For this purpose the production of reactive oxygen species (ROS) was measured by flow cytometry in human lymphoblastoid cells exposed to 1950 MHz signal used by the third generation wireless technology of the Universal Mobile Telecommunication System (UMTS) at Specific Absorption Rate of 0.5 and 2.0 W/kg. Short (5-60 min) or long (24 h) duration exposures were carried out in a waveguide system under strictly controlled conditions of both dosimetry and environment. Cell viability was also measured after 24 h RF exposure using the Resazurin and Neutral Red assays. Several co-exposure protocols were applied to tes...

Effects of W-CDMA 1950 MHz EMF emitted by mobile phones on regional cerebral blood flow in humans

Bioelectromagnetics — Wed, 27 May 2009 04:00:00 +0100

Use of the third generation mobile phone system is increasing worldwide. This is the first study to investigate the effects of the third generation system on regional cerebral blood flow (rCBF) in humans. We compared effects of the electromagnetic field (EMF) emitted from the Wideband Code Division Multiple Access (W-CDMA) cellular system versus sham control exposure on rCBF in humans. Nine healthy male volunteers participated in this study. Positron emission tomography (PET) scans were obtained before, during, and after unilateral 30 min EMF exposure. The subtraction analysis revealed no significant rCBF changes caused by the EMF conditions compared with the sham exposure, suggesting that EMF emitted by a third generation mobile phone does not affect rCBF in humans. Bioelectromagnetics, 2...

Large gradient high magnetic field affects the association of MACF1 with actin and microtubule cytoskeleton

Bioelectromagnetics — Wed, 27 May 2009 04:00:00 +0100

In conclusion, LG-HMF affects osteoblast-like cell viability, MACF1 distribution, expression, and its association with cytoskeleton to some extent. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls

Bioelectromagnetics — Wed, 27 May 2009 04:00:00 +0100

Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m2 to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-...

Low-frequency conductivity tensor of rat brain tissues inferred from diffusion MRI

Bioelectromagnetics — Fri, 15 May 2009 04:00:00 +0100

Conductivity tensor maps of the rat brain were obtained using diffusion magnetic resonance imaging (MRI). Signal attenuations in the cortex and the corpus callosum were measured using the stimulated echo acquisition mode (STEAM) sequence with b factors up to 6000 s/mm2. Our previously published method was improved to infer 3 × 3 conductivity tensor at the low-frequency limit. The conductivity tensor of the tissue was inferred from the fast component of the diffusion tensor and a fraction of the fast component. The mean conductivity (MC) of the cortex and the corpus callosum was 0.52 and 0.62 S/m, respectively. Diffusion-weighted images were obtained with b factors up to 4500 s/mm2. Conductivity tensor images were calculated from the fast diffusion tensor images. Tissues with highly anisot...

Effect of ultra-strong static magnetic field on bacteria: Application of Fourier-transform infrared spectroscopy combined with cluster analysis and deconvolution

Bioelectromagnetics — Wed, 13 May 2009 04:00:00 +0100

A new method based on Fourier-transform infrared (FTIR) spectroscopy combined with cluster analysis and deconvolution was established to investigate the biological effect of an ultra-strong static magnetic field (SMF) of 10.0 T on Escherichia coli and Staphylococcus aureus. FTIR spectroscopy was applied to characterize the spectroscopic fingerprints of these bacterial cells with or without the treatment of the SMF. After the calculation, the results of cluster analysis indicated that the SMF had significant effects on E. coli compared with S. aureus, and the effects were reflected by the changes of spectral region of 1500-1200 cm-1. The deconvolution results of this major indication region showed that the composition and conformation of nucleic acid, protein, and fatty acid of E. coli were...

A Lorentz model for weak magnetic field bioeffects: Part I - Thermal noise is an essential component of AC/DC effects on bound ion trajectory

Bioelectromagnetics — Tue, 12 May 2009 04:00:00 +0100

We have previously employed the Lorentz-Langevin model to describe the effects of weak exogenous magnetic fields via the classical Lorentz force on a charged ion bound in a harmonic oscillator potential, in the presence of thermal noise forces. Previous analyses predicted that µT-range fields give rise to a rotation of the oscillator orientation at the Larmor frequency and bioeffects were based upon the assumption that the classical trajectory of the bound charge itself could modulate a biochemical process. Here, it is shown that the thermal component of the motion follows the Larmor trajectory. The results show that the Larmor frequency is independent of the thermal noise strength, and the motion retains the form of a coherent oscillator throughout the binding lifetime, rather than devol...

A Lorentz model for weak magnetic field bioeffects: Part II - Secondary transduction mechanisms and measures of reactivity

Bioelectromagnetics — Tue, 12 May 2009 04:00:00 +0100

In Part I it was shown that the thermal component of the motion of a charged particle in an oscillator potential, that is, within a molecular binding site, rotates at the Larmor frequency in an applied magnetic field. It was also shown that the Larmor angular frequency is independent of the thermal noise strength and thus offers a mechanism for the biological detection of weak (µT-range) magnetic fields. Part II addresses the question of how the Larmor trajectory could affect biological reactivity. The projection of the motion onto a Cartesian axis measures the nonuniformity of the Larmor trajectory in AC and combined AC/DC magnetic fields, suggesting a means of assessing resonances. A physically meaningful measure of reactivity based upon the classical oscillator trajectory is suggested,...

Features of anti-inflammatory effects of modulated extremely high-frequency electromagnetic radiation

Bioelectromagnetics — Sun, 10 May 2009 04:00:00 +0100

Using a model of acute zymosan-induced paw edema in NMRI mice, we test the hypothesis that anti-inflammatory effects of extremely high-frequency electromagnetic radiation (EHF EMR) can be essentially modified by application of pulse modulation with certain frequencies. It has been revealed that a single exposure of animals to continuous EHF EMR for 20 min reduced the exudative edema of inflamed paw on average by 19% at intensities of 0.1-0.7 mW/cm2 and frequencies from the range of 42.2-42.6 GHz. At fixed effective carrier frequency of 42.2 GHz, the anti-inflammatory effect of EHF EMR did not depend on modulation frequencies, that is, application of different modulation frequencies from the range of 0.03-100 Hz did not lead to considerable changes in the effect level. On the contrary, at "...

Response to comments on cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation by Nittby et al. (Bioelectromagnetics 29:219-232, 2008)

Bioelectromagnetics — Fri, 08 May 2009 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Current density in a model of a human body with a conductive implant exposed to ELF electric and magnetic fields

Bioelectromagnetics — Thu, 07 May 2009 04:00:00 +0100

A numerical model of a human body with an intramedullary nail in the femur was built to evaluate the effects of the implant on the current density distribution in extremely low frequency electric and magnetic fields. The intramedullary nail was chosen because it is one of the longest high conductive implants used in the human body. As such it is expected to alter the electric and magnetic fields significantly. The exposure was a simultaneous combination of inferior to superior electric field and posterior to anterior magnetic field both alternating at 50 Hz with the values corresponding to the ICNIRP reference levels: 5000 V m-1 for electric field and 100 µT for magnetic flux density. The calculated current density distribution inside the model was compared to the ICNIRP basic restriction...

Comments on "cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation" by Nittby et al. (Bioelectromagnetics 29:219-232, 2008)

Bioelectromagnetics — Mon, 04 May 2009 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Inhibitory effects of a gradient static magnetic field on normal angiogenesis

Bioelectromagnetics — Thu, 30 Apr 2009 04:00:00 +0100

In this study, the effects of GSMF (0.2-0.4 T, 2.09 T/m, 1-11 days) on angiogenesis were investigated both in vitro and in vivo. An MTT assay was used as an in vitro method to detect the proliferation ability of human umbilical veins endothelial cells (HUVECs). Two kinds of in vivo models, a chick chorioallantoic membrane (CAM) and a matrigel plug, were used to detect the effects of GSMF on angiogenesis. The results showed that the proliferation ability of HUVECs was significantly inhibited 24 h after the onset of exposure. With regard to the CAM model, vascular numbers in the CAM that was continuously exposed to the GSMF were all less than those in normal condition. In accordance with the gross appearance, the contents of hemoglobin in the models exposed to GSMF for 7-9 days were also les...

Exposure to inhomogeneous static magnetic field ceases mechanical allodynia in neuropathic pain in mice

Bioelectromagnetics — Wed, 29 Apr 2009 04:00:00 +0100

Magnetic therapy as a self-care intervention has led to the conduct of numerous human trials and animal experiments. Results concerning the analgesic efficacy of magnetic exposure, however, are inconsistent. By using a magnetic device generating an inhomogeneous static magnetic field (iSMF), here we studied how the whole-body exposure to iSMF may influence the mechanical withdrawal threshold (MWT) of the hind paw in different stages of neuropathic pain evoked by partial ligation of the sciatic nerve in mice. It was found that iSMF exposure did not prevent the decrease of MWT in the first postoperative week. A 2-week long iSMF treatment that was started just after the nerve ligation elevated MWT values to a modest extent. However, the effectiveness of a daily exposure to iSMF was much more ...

Self-report of physical symptoms associated with using mobile phones and other electrical devices

Bioelectromagnetics — Tue, 28 Apr 2009 04:00:00 +0100

The aim of our work was to study the working-age population's self-reported physical symptoms associated with using mobile phones and other electrical devices. A qualitative method was applied using an open-ended question in a questionnaire, which included questions about the possible influence of new technical equipment on health. We then created subgroups of respondents for different self-reported symptoms associated with mobile phones and other electrical devices. The research questions were: (1) how the respondents described physical symptoms associated with using mobile phones and other electrical devices and (2) how the answers can be classified into subgroups based on symptoms or devices. We identified the following categories: (1) respondents with different self-reported symptoms w...

Most influential bioelectromagnetics journal paper by Citation award

Bioelectromagnetics — Mon, 27 Apr 2009 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Effects of pulsed electromagnetic stimulation on patients undergoing hip revision prostheses: A randomized prospective double-blind study

Bioelectromagnetics — Tue, 21 Apr 2009 04:00:00 +0100

Electromuscular incapacitation results from stimulation of spinal reflexes

Bioelectromagnetics — Thu, 09 Apr 2009 04:00:00 +0100

Electronic stun devices (ESD) often used in law enforcement, military action or self defense can induce total body uncoordinated muscular activity, also known as electromuscular incapacitation (EMI). During EMI the subject is unable to perform purposeful or coordinated movements. The mechanism of EMI induction has not been reported, but has been generally thought to be direct muscle and nerve excitation from the fields generated by ESDs. To determine the neuromuscular mechanisms linking ESD to induction of EMI, we investigated EMI responses using an anesthetized pig model. We found that EMI responses to ESD application can best be simulated by simultaneous stimulation of motor and sensory peripheral nerves. We also found that application of local anesthetics limited the response of ESD to ...

Response to comments on the paper "spindle disturbances in human hamster hybrid (AL) cells" by Mays Swicord

Bioelectromagnetics — Mon, 30 Mar 2009 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Comment on "spindle disturbances in human hamster hybrid (AL) cells [hellip]" by T. Schrader et al.

Bioelectromagnetics — Fri, 27 Mar 2009 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Radiation from mobile phone systems: Is it perceived as a threat to people's health?

Bioelectromagnetics — Mon, 23 Mar 2009 04:00:00 +0100

The aim of this study was to explore the prevalence, nature and determinants of concerns about mobile phone radiation. We used data from a 2006 telephone survey of 1004 people aged 15+ years in Denmark. Twenty-eight percent of the respondents were concerned about exposure to mobile phone radiation; radiation from masts was of concern to about 15%. In contrast, 82% were concerned about pollution. Nearly half of the respondents considered the mortality risk of 3G phones and masts to be of the same order of magnitude as being struck by lightning (0.1 fatalities per million people per year) while 7% thought it was equivalent to tobacco-induced lung cancer ([sim]500 fatalities per million per year). Among women, concerns about mobile phone radiation were positively associated with educational a...

The puzzle of magnetic resonance effect on the magnetic compass of migratory birds

Bioelectromagnetics — Tue, 17 Mar 2009 04:00:00 +0100

Experiments on the effect of radio-frequency (RF) magnetic fields on the magnetic compass orientation of migratory birds are analyzed using the theory of magnetic resonance. The results of these experiments were earlier interpreted within the radical-pair model of magnetoreception. However, the consistent analysis shows that the amplitudes of the RF fields used are far too small to noticeably influence electron spins in organic radicals. Other possible agents that could mediate the birds' response to the RF fields are discussed, but apparently no known physical system can be responsible for this effect. Bioelectromagnetics, 2009 © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

An electronic device for accelerating bone formation in tissues surrounding a dental implant

Bioelectromagnetics — Sun, 15 Mar 2009 04:00:00 +0100

This study presents an electronic device that is temporarily connected with the dental implant, and reports its effect on accelerating bone formation in the surrounding tissues in a canine mandibular model. A small sized and low power consumption biphasic electrical current (BEC) stimulator ASIC was developed and the surrounding tissue was exposed to continuous BEC stimulation for 7 days with the parameters of 20 µA/cm2, 125 µs duration, and 100 pulses/s. After 2 (n = 5) and 5 weeks (n = 5), animals were sacrificed and the specimens were histomorphometrically evaluated. The newly formed bone area (BA) was 1.30 times (3 weeks, P < 0.05) and 1.35 times (5 weeks, P < 0.05) higher in the experimental group compared to the control group, respectively. Bone-implant contact (BIC) in 3-week spec...

Study of narrow band millimeter-wave potential interactions with endoplasmic reticulum stress sensor genes

Bioelectromagnetics — Thu, 12 Mar 2009 04:00:00 +0100

The main purpose of this article is to study potential biological effects of low-power millimeter waves (MMWs) on endoplasmic reticulum (ER), an organelle sensitive to a wide variety of environmental insults and involved in a number of pathologies. We considered exposure frequencies around 60 GHz in the context of their near-future applications in wireless communication systems. Radiations within this frequency range are strongly absorbed by oxygen molecules, and biological species have never been exposed to such radiations in natural environmental conditions. A set of five discrete frequencies has been selected; three of them coincide with oxygen spectral lines (59.16, 60.43, and 61.15 GHz) and two frequencies correspond to the spectral line overlap regions (59.87 and 60.83 GHz). Moreover...

Effects of radio frequency magnetic fields on iron release from cage proteins

Bioelectromagnetics — Mon, 09 Mar 2009 04:00:00 +0100

Ferritin, the iron cage protein, contains a superparamagnetic ferrihydrite nanoparticle formed from the oxidation and absorption of Fe2+ ions. This nanoparticle increases its internal energy when exposed to alternating magnetic fields due to magnetization lag. The energy is then dissipated to the surrounding proteic cage, affecting its functioning. In this article we show that the rates of iron chelation with ferrozine, an optical marker, are reduced by up to a factor of 3 in proteins previously exposed to radio frequency magnetic fields of 1 MHz and 30 µT for several hours. The effect is non-thermal and depends on the frequency-amplitude product of the magnetic field. Bioelectromagnetics, 2009. © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Effect of weak combined static and extremely low-frequency alternating magnetic fields on tumor growth in mice inoculated with the Ehrlich ascites carcinoma

Bioelectromagnetics — Sun, 08 Mar 2009 05:00:00 +0100

It has been shown that the ultralow-frequency extremely weak alternating component of combined magnetic fields (MFs) exhibits a marked antitumor activity. The parameters of this component have been found (frequency 1, 4.4, 16.5 Hz or the sum of these frequencies; intensity 300, 100, 150-300 nT, respectively) at which this MF in combination with a collinear static MF of 42 µT inhibits or suppresses the growth of Ehrlich ascites carcinoma (EAC) in mice. It was shown that the exposure of mice with EAC to combined MFs causes structural changes in some organs (liver, adrenal glands), which are probably due to the total degradation of the tumor tissue. In mice with transplanted EAC, the tumor tissue after exposure to weak MFs was practically absent, as distinct from control animals in which the...

Blood laboratory findings in patients suffering from self-perceived electromagnetic hypersensitivity (EHS)

Bioelectromagnetics — Wed, 04 Mar 2009 05:00:00 +0100

Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge. We hypothesized that some electrosensitive individuals are suffering from common somatic health problems. Toward this end we analysed clinical laboratory parameters including thyroid-stimulating hormone (TSH), alanine transaminase (ALT), aspartate transaminase (AST), creatinine, hemoglobine, hematocrit and c-reactive protein (CRP) in subjects suffering from EHS and in controls that are routinely used in clinical medicine to identify or screen for common somatic disorders. One hundred thirty-two patients (n = 42 males and n = 90 female...

No effects of UMTS exposure on the function of rat outer hair cells

Bioelectromagnetics — Thu, 26 Feb 2009 05:00:00 +0100

UMTS communication devices are becoming common in everyday use. This could raise public concern about their possible detrimental effects on human health. The aim of this study, in the framework of the EMF nEAR Project, was to evaluate possible influence of UMTS electromagnetic fields (EMF) exposure on cochlear outer hair cells' (OHCs) functionality in laboratory animals. Forty-eight male Sprague-Dawley rats were locally exposed (right ear) or sham-exposed to a controlled UMTS EMF, frequency of 1946 MHz, at SAR level of 10 W/kg, 2 h a day, 5 days a week, for 4 weeks. A group of 12 rats treated with kanamycin (KM) was also included as positive control. Rats were tested by recording Distortion Product Otaoacoustic Emissions (DPOAEs), a non-invasive test capable of assessing the status of the ...

Exposure to a MRI-type high-strength static magnetic field stimulates megakaryocytic/erythroid hematopoiesis in CD34+ cells from human placental and umbilical cord blood

Bioelectromagnetics — Tue, 24 Feb 2009 05:00:00 +0100

The biological response after exposure to a high-strength static magnetic field (SMF) has recently been widely discussed from the perspective of possible health benefits as well as potential adverse effects. To clarify this issue, CD34+ cells from human placental and umbilical cord blood were exposed under conditions of high-strength SMF in vitro. The high-strength SMF exposure system was comprised of a magnetic field generator with a helium-free superconducting magnet with built-in CO2 incubator. Freshly prepared CD34+ cells were exposed to a 5 tesla (T) SMF with the strongest magnetic field gradient (41.7 T/m) or a 10 T SMF without magnetic field gradient for 4 or 16 h. In the harvested cells after exposure to 10 T SMF for 16 h, a significant increase of hematopoietic progenitors in the ...

Growth inhibition of Staphylococcus aureus induced by low-frequency electric and electromagnetic fields

Bioelectromagnetics — Fri, 20 Feb 2009 05:00:00 +0100

This study focuses on the impact of different electric and electromagnetic fields on the growth of Staphylococcus aureus by in vitro technologies. Cultures of Staphylococcus aureus in fluid and gel-like medium were exposed to a low-frequency electromagnetic field, an electromagnetic field combined with an additional electric field, a sinusoidal electric field and a static electric field. In gel-like medium no significant difference between colony-forming units of exposed samples and non-exposed references was detected. In contrast, Staphylococcus aureus concentrations in fluid medium could clearly be reduced under the influence of the four different applied fields within 24 h of experiment. The strongest effects were observed for the direct current electric field which could decrease CFU/m...

Effect of pulsed electromagnetic field on the proliferation and differentiation potential of human bone marrow mesenchymal stem cells

Bioelectromagnetics — Wed, 11 Feb 2009 05:00:00 +0100

Pulsed electromagnetic fields (PEMFs) have been used clinically to slow down osteoporosis and accelerate the healing of bone fractures for many years. The aim of this study is to investigate the effect of PEMFs on the proliferation and differentiation potential of human bone marrow mesenchymal stem cells (BMMSC). PEMF stimulus was administered to BMMSCs for 8 h per day during culture period. The PEMF applied consisted of 4.5 ms bursts repeating at 15 Hz, and each burst contained 20 pulses. Results showed that about 59% and 40% more viable BMMSC cells were obtained in the PEMF-exposed cultures at 24 h after plating for the seeding density of 1000 and 3000 cells/cm2, respectively. Although, based on the kinetic analysis, the growth rates of BMMSC during the exponential growth phase were not ...

Effect of 100 mT homogeneous static magnetic field on [Ca2+]c response to ATP in HL-60 cells following GSH depletion

Bioelectromagnetics — Mon, 09 Feb 2009 05:00:00 +0100

Calcium is an important molecule in a number of biological systems. Often these systems are signal transduction cascades involving molecules such as ATP. ATP activates second messengers which can interact with ion channels on the endoplasmic/sarcoplasmic reticulum resulting in the emptying of the intracellular calcium stores and an increase in cytosolic free calcium concentration ([Ca2+]c). Changes in [Ca2+]c can be influenced by external factors such as a static magnetic field (SMF). One hypothesis suggests that a SMF affects the cells through the radical pair mechanism. By reducing the number of antioxidant molecules like glutathione (GSH), the proportion of free radicals in the cells is increased and may lead to a greater probability of a biological response to a SMF. The purpose of thi...

Specific absorption rate and electric field measurements in the near field of six mobile phone base station antennas

Bioelectromagnetics — Thu, 05 Feb 2009 05:00:00 +0100

In this article, the exposure to radio frequency electromagnetic fields was studied in close proximity (distances of 10, 100, 300, and 600 mm) to six base station antennas. The specific absorption rate (SAR) in 800 mm × 500 mm × 200 mm box phantom as well as unperturbed electric field (E) in air was measured. The results were used to determine whether the measurement of local maximum of unperturbed electric field can be used as a compliance check for local exposure. Also, the conservativeness of this assessment method compared to the ICNIRP basic restriction was studied. Moreover, the assessment of whole-body exposure was discussed and the distance ranges presented in which the ICNIRP limit for local exposure could be exceeded before the limit for whole-body SAR. These results show that ...

Quantitative assessment of dielectric parameters for membrane lipid bi-layers from RF permittivity measurements

Bioelectromagnetics — Wed, 04 Feb 2009 05:00:00 +0100

In this article, we propose and validate theoretical and experimental methods to quantitatively assess the Debye dielectric model of membrane lipid bi-layers. This consists of two steps: permittivity measurements of biological solutions (liposomes), and estimation of the model parameters by inverse application of the Effective Medium Theory. The measurements are conducted in the frequency domain between 100 MHz and 2 GHz using a modified coaxial connector, at the temperatures of 27 and 30 °C. Estimations have been performed using a three-layered model based on the Maxwell-Wagner formulation. Debye parameters (mean value ± standard error) found from fitting experimental data are: [epsiv]s = 11.69 ± 0.09, [epsiv][infin] = 4.00 ± 0.07, frelax = 179.85 ± 6.20 MHz and [epsiv]s = (1.1 ± 0....

Morphofunctional study of 12-O-tetradecanoyl-13-phorbol acetate (TPA)-induced differentiation of U937 cells under exposure to a 6 mT static magnetic field

Bioelectromagnetics — Tue, 03 Feb 2009 05:00:00 +0100

This study deals with the morphofunctional influence of 72 h exposure to a 6 mT static magnetic field (SMF) during differentiation induced by 50 ng/ml 12-O-tetradecanoyl-13-phorbol acetate (TPA) in human leukaemia U937 cells. The cell morphology of U937 cells was investigated by optic and electron microscopy. Specific antibodies and/or molecules were used to label CD11c, CD14, phosphatidylserine, F-actin and to investigate the distribution and activity of lysosomes, mitochondria and SER. [Ca2+]i was evaluated with a spectrophotometer. The degree of differentiation in SMF-exposed cells was lower than that of non-exposed cells, the difference being exposure time-dependent. SMF-exposed cells showed cell shape and F-actin modification, inhibition of cell attachment, appearance of membrane roug...

Personal exposure to mobile communication networks and well-being in children - A statistical analysis based on a functional approach

Bioelectromagnetics — Fri, 30 Jan 2009 05:00:00 +0100

The MobilEe-study was the first cross-sectional population-based study to investigate possible health effects of mobile communication networks on children using personal dosimetry. Exposure was assessed every second resulting in 86,400 measurements over 24 h for each participant. Therefore, a functional approach to analyze the exposure data was considered appropriate. The aim was to categorize exposure taking into account the course of the measurements over 24 h. The analyses were based on the 480 maxima of each 3 min time interval. Exposure was classified using a nonparametric functional method. Heterogeneity of a sample of functional data was assessed by comparing the functional mode and mean of the distribution of a functional variable. The partition was built within a descending hierar...

Effects of static magnetic field on magnetosome formation and expression of mamA, mms13, mms6 and magA in Magnetospirillum magneticum AMB-1

Bioelectromagnetics — Fri, 23 Jan 2009 05:00:00 +0100

Magnetotactic bacteria produce nanometer-size intracellular magnetic crystals. The superior crystalline and magnetic properties of magnetosomes have been attracting much interest in medical applications. To investigate effects of intense static magnetic field on magnetosome formation in Magnetospirillum magneticum AMB-1, cultures inoculated with either magnetic or non-magnetic pre-cultures were incubated under 0.2 T static magnetic field or geomagnetic field. The results showed that static magnetic field could impair the cellular growth and raise Cmag values of the cultures, which means that the percentage of magnetosome-containing bacteria was increased. Static magnetic field exposure also caused an increased number of magnetic particles per cell, which could contribute to the increased c...

Mobile phone use and location of glioma: A case-case analysis

Bioelectromagnetics — Tue, 13 Jan 2009 05:00:00 +0100

We assessed a new approach for evaluating the glioma risk among users of mobile phones to focus on the part of the brain most heavily exposed to radiofrequency electromagnetic fields from mobile phones. The tumor midpoint was defined from radiological imaging. A case-case analysis with 99 gliomas was performed using logistic regression. The exposed cases were those with the tumor mid-point within 4.6 cm from the line between the mouth and the external meatus of the ear, representing the most likely location of the mobile phone (the source of exposure). Alternative analyses based on various indicators of mobile phone use as the outcome were also carried out. The majority of cases were regular mobile phone users. A slightly higher proportion of gliomas among mobile phone users than non-users...

Evaluation of current densities and total contact currents in occupational exposure at 400 kV substations and power lines

Bioelectromagnetics — Tue, 13 Jan 2009 05:00:00 +0100

This investigation studied the current densities in the neck and total contact currents in occupational exposure at 400 kV substations and power lines. Eight voluntary workers simulated their normal work tasks using the helmet-mask measuring system. In all, 151 work tasks with induced current measurements were made. Work situations were: tasks in 400 kV substations, tasks in 400-110 kV towers and the cutting of vegetation under 400 kV power lines. The average current density in the neck was estimated from the current induced in the helmet. The calculated maximum average current densities in the neck varied from 1.5 to 6.4 mA/m2 and the maximum total contact currents from 66.8 to 458.4 µA. The study shows that the maximum average current densities and the total contact currents (caused by ...

Preattentive auditory information processing under exposure to the 902 MHz GSM mobile phone electromagnetic field: A mismatch negativity (MMN) study

Bioelectromagnetics — Mon, 12 Jan 2009 05:00:00 +0100

In this study, MMN responses to duration, intensity, frequency, and gap changes were recorded in healthy young adults (n = 17), using a multifeature paradigm including several types of auditory change in the same stimulus sequence, while a GSM mobile phone was placed on either ear with the EMF (902 MHz pulsed at 217 Hz; SAR1g = 1.14 W/kg, SAR10g = 0.82 W/kg, peak value = 1.21 W/kg, measured with an SAM phantom) on or off. An MMN was elicited by all deviant types, while its amplitude and latency showed no significant differences due to EMF exposure for any deviant types. In the present study, we found no conclusive evidence that acute exposure to GSM mobile phone EMF affects cortical auditory change detection processing reflected by the MMN. Bioelectromagnetics. © 2009 Wiley-Liss, Inc. (So...

Teratological evaluation of mouse fetuses exposed to a 20 kHz EMF

Bioelectromagnetics — Mon, 12 Jan 2009 05:00:00 +0100

As a continuation of our previous study, we performed a teratological evaluation of the importance of gestational age with regards to the exposure of 20 kHz intermediate frequency magnetic field (IF) on pregnant ICR mice. The pregnant mice were exposed to a 20 kHz IF magnetic field for 8 h/day in a carousel irradiator at 30 µT which is the limit standard for occupational population in Korea. The animals were sacrificed on the 18th day of gestation and the fetuses were examined for mortality, growth retardation, changes in head size and other morphological abnormalities. We concluded that exposure to 30 µT with 20 kHz IF did not cause any observable adverse effects on mouse fetuses. Bioelectromagnetics. © 2009 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Power frequency magnetic fields and risk of childhood leukaemia: Misclassification of exposure from the use of the 'distance from power line' exposure surrogate

Bioelectromagnetics — Sat, 20 Dec 2008 04:21:07 +0100

A recent study examining the relationship between distance to nearby power lines and childhood cancer risk re-opened the debate about which exposure metrics are appropriate for power frequency magnetic field investigations. Using data from two large population-based UK and German studies we demonstrate that distance to power lines is a comparatively poor predictor of measured residential magnetic fields. Even at proximities of 50 m or less, the positive predictive value of having a household measurement over 0.2 µT was only 19.4%. Clearly using distance from power lines, without taking account of other variables such as load, results in a poor proxy of residential magnetic field exposure. We conclude that such high levels of exposure misclassification render the findings from studies that...

Comment: Did undetected AC components affect a DC magnetic field experiment? (Vashisth A, Nagarajan S. 2008. Bioelectromagnetics 29:571-578)

Bioelectromagnetics — Tue, 16 Dec 2008 05:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Assessment of the efficacy and safety of low frequency, low intensity magnetic fields in patients after knee endoprosthesis plasty. Part 2: A Clinical Study

Bioelectromagnetics — Tue, 16 Dec 2008 05:00:00 +0100

The purpose of this clinical study was to assess low frequency, low intensity magnetic fields in the enhancement of the physical rehabilitation of patients after knee endoprosthesis surgery. The study included 62 patients who underwent total knee arthroplasty. Group A consisted of 32 patients who were physically rehabilitated. Group B consisted of 30 patients who were physically rehabilitated and treated additionally with pulsing magnetic fields (5 mT, 30 Hz, 20 min once a day, 5 days weekly). Therapy lasted 3 weeks for both groups. The rehabilitation process was evaluated using a goniometer, tensometer, goniometric pendulum test, Lysholm scale for knee function, and a visual analogue scale (VAS) questionnaire for pain and activity. The changes of measured rates were comparable in both gro...

900 MHz modulated electromagnetic fields accelerate the clathrin-mediated endocytosis pathway

Bioelectromagnetics — Mon, 15 Dec 2008 03:51:52 +0100

We report new data regarding the molecular mechanisms of GSM-induced increase of cell endocytosis rate. Even though endocytosis represents an important physical and biological event for cell physiology, studies on modulated electromagnetic fields (EMF) effects on this process are scarce. In a previous article, we showed that fluid phase endocytosis rate increases when cultured cells are exposed to 900 MHz EMF similar to mobile phones' modulated GSM signals (217 Hz repetition frequency, 576 µs pulse width) and to electric pulses similar to the GSM electrical component. Trying to distinguish the mechanisms sustaining this endocytosis stimulation, we exposed murine melanoma cells to Lucifer Yellow (LY) or to GSM-EMF/electric pulses in the presence of drugs inhibiting the clathrin- or the cav...

Effects of 100 GHz radiation on alkaline phosphatase activity and antigen-antibody interaction

Bioelectromagnetics — Thu, 04 Dec 2008 05:00:00 +0100

Equipment that generates microwave radiation (MWR) spanning the frequency range of 300 MHz-100 GHz is becoming more common. While MWR lacks sufficient energy to break chemical bonds, the disagreement as to whether MWR exposure is detrimental to cellular dysfunction may be difficult to clarify using complex systems such as whole animals, cells, or cell extracts. Recently, the high frequency range of terahertz (THz) radiation has been explored and sources of radiation and its detectors have been developed. THz radiation is associated with the frequency interval from 100 GHz to 20 THz and constitutes the next frontier in imaging science and technology. In the present study, we investigated the effect of radiation in the low frequency THz range (100 GHz) on two defined molecular interactions. ...

X-ray-induced apoptosis of BEL-7402 cell line enhanced by extremely low frequency electromagnetic field in vitro

Bioelectromagnetics — Tue, 02 Dec 2008 05:00:00 +0100

This study was designed to test whether extremely low frequency electromagnetic field (ELF-EMF) could enhance the apoptosis-induction effect of X-ray radiotherapy on liver cancer cell line BEL-7402 in vitro. EMF exposure was performed inside an energized solenoid coil. X-ray irradiation was performed using a linear accelerator. Apoptosis rates of BEL-7402 cells were analyzed using Annexin V-Fit Apoptosis Detection kit. Apoptosis rates of EMF group and sham EMF group were compared when combined with X-ray irradiation. Our results suggested that the apoptosis rate of BEL-7402 cells exposed to low doses of X-ray irradiation could be significantly increased by EMF. More EMF exposures obtain significantly higher apoptosis rates than fewer EMF exposures when combined with 2 Gy X-ray irradiation....

An evaluation of exposure metrics in an epidemiologic study on radio and television broadcast transmitters and the risk of childhood leukemia

Bioelectromagnetics — Sat, 22 Nov 2008 05:00:00 +0100

Electric field strength values calculated by wave propagation modeling were applied as an exposure metric in a case-control study conducted in Germany to investigate a possible association between radio frequency electromagnetic fields (RF-EMF) emitted from television and radio broadcast transmitters and the risk of childhood leukemia. To validate this approach it was examined at 850 measurement sites whether calculated RF-EMF are an improvement to an exposure proxy based on distance from the place of residence to a transmitter. Further, the agreement between measured and calculated RF-EMF was explored. For dichotomization at the 90% quantiles of the exposure distributions it was found that distance agreed less with measured RF-EMF (Kappa coefficient: 0.55) than did calculated RF-EMF (Kapp...

Real-time measurement of cytosolic free calcium concentration in DEM-treated HL-60 cells during static magnetic field exposure and activation by ATP

Bioelectromagnetics — Fri, 21 Nov 2008 05:00:00 +0100

This study investigated whether glutathione depletion affected the sensitivity of HL-60 cells to static magnetic fields. The effect of Diethylmaleate (DEM) on static magnetic field induced changes in cytosolic free calcium concentration ([Ca2+]c) was examined. Cells were loaded with a fluorescent dye and exposed to a uniform static magnetic field at a strength of 0 mT (sham) or 100 mT. [Ca2+]c was monitored during field and sham exposure using a ratiometric fluorescence spectroscopy system. Cells were activated by the addition of ATP. Metrics extracted from the [Ca2+]c time series included: average [Ca2+]c during the Pre-Field and Field Conditions, peak [Ca2+]c following ATP activation and the full width at half maximum (FWHM) of the peak ATP response. Comparison of each calcium metric bet...

Effects of gestational exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats

Bioelectromagnetics — Tue, 18 Nov 2008 05:00:00 +0100

The present study was designed to evaluate whether gestational exposure to an EMF targeting the head region, similar to that from cellular phones, might affect embryogenesis in rats. A 1.95-GHz wide-band code division multiple access (W-CDMA) signal, which is one applied for the International Mobile Telecommunication 2000 (IMT-2000) system and used for the freedom of mobile multimedia access (FOMA), was employed for exposure to the heads of four groups of pregnant CD(SD) IGS rats (20 per group) for gestational days 7-17. The exposure was performed for 90 min/day in the morning. The spatial average specific absorption rate (SAR) for individual brains was designed to be 0.67 and 2.0 W/kg with peak brain SARs of 3.1 and 7.0 W/kg for low (group 3) and high (group 4) exposures, respectively, an...

Osteoblasts stimulated with pulsed electromagnetic fields increase HUVEC proliferation via a VEGF-A independent mechanism

Bioelectromagnetics — Mon, 17 Nov 2008 05:00:00 +0100

We examined the role of the pro-angiogenic mediator VEGF-A in the mitogenic effect of ELF-PEMF-stimulated osteoblast media on endothelial cells. The production of VEGF-A by FRC as measured by ELISA was not changed by exposure to PEMF, and blocking experiments demonstrated that the ELF-PEMF-induced osteoblast-derived endothelial mitogen observed in these studies was not VEGF-A, but some other soluble angiogenic mediator. Bioelectromagnetics, 2009 © 2008 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Cognitive effects of radiation emitted by cellular phones: The influence of exposure side and time

Bioelectromagnetics — Mon, 17 Nov 2008 05:00:00 +0100

This study examined the time dependence effects of exposure to radiofrequency radiation (RFR) emitted by standard GSM cellular phones on the cognitive functions of humans. A total of 48 healthy right-handed male subjects performed a spatial working memory task (that required either a left-hand or a right-hand response) while being exposed to one of two GSM phones placed at both sides of the head. The subjects were randomly divided into three groups. Each group was exposed to one of three exposure conditions: left-side of the head, right-side, or sham-exposure. The experiment consisted of 12 blocks of trials. Response times (RTs) and accuracy of the responses were recorded. It was found that the average RT of the right-hand responses under left-side exposure condition was significantly long...

Assessment of the efficacy and safety of low frequency, low intensity magnetic fields in patients after knee endoprosthesis plasty (part 1): In vitro safety

Bioelectromagnetics — Fri, 14 Nov 2008 05:00:00 +0100

The purpose of this in vitro study was to assess the potential influence of low frequency, low intensity magnetic fields (rectangular pulse, 5 mT, 30 Hz) applied in therapy on the temperature, contact electric potential, and magnetization in knee endoprosthesis, which might be dangerous for implantation and stability of knee prosthesis, and later slacking it off, causing postoperative complications. The experimental investigation was carried out on a knee endoprosthesis which had been placed in a container with physiological saline. The prosthesis located inside the container was under the exposure of the magnetic field applied by a solenoid. The results indicated that magnetic fields did not influence thermal and electromagnetic properties of knee endoprosthesis in vitro. The magnetic fie...

FDTD assessment of human exposure to electromagnetic fields from WiFi and bluetooth devices in some operating situations

Bioelectromagnetics — Tue, 21 Oct 2008 04:00:00 +0100

In this work, the numerical dosimetry in human exposure to the electromagnetic fields from antennas of wireless devices, such as those of wireless local area networks (WLAN) access points or phone and computer peripherals with Bluetooth antennas, is analyzed with the objective of assessing guidelines compliance. Several geometrical configurations are considered to simulate possible exposure situations of a person to the fields from WLAN or Bluetooth antennas operating at 2400 MHz. The exposure to radiation from two sources of different frequencies when using a 1800 MHz GSM mobile phone connected via Bluetooth with a hands-free car kit is also considered. The finite-difference time-domain (FDTD) method is used to calculate electric and magnetic field values in the vicinity of the antennas a...

Editor's Note

Bioelectromagnetics — Mon, 20 Oct 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

On Wolf's brief communication

Bioelectromagnetics — Mon, 20 Oct 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Comments on the Brief Communication "Security considerations in blinded exposure experiments using electromagnetic waves" by Christian Wolf

Bioelectromagnetics — Fri, 10 Oct 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Effects of 60 Hz 14 µT magnetic field on the apoptosis of testicular germ cell in mice

Bioelectromagnetics — Tue, 07 Oct 2008 04:00:00 +0100

We recently reported that continuous exposure, for 8 weeks, of extremely low frequency (ELF) magnetic field (MF) of 0.1 or 0.5 mT might induce testicular germ cell apoptosis in BALB/c mice. In that report, the ELF MF exposure did not significantly affect the body weight or testicular weight, but significantly increased the incidence of testicular germ cell death. In the present study, we aimed to further characterize the effect of a 16-week continuous exposure to ELF MF of 14 or 200 µT on testicular germ cell apoptosis in mice. There were no significant effects of MF on body weight and testosterone levels in mice. In TUNEL staining (In situ terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling), germ cells showed a significantly higher apoptotic rate in exposed mice t...

Microwaves from UMTS/GSM mobile phones induce long-lasting inhibition of 53BP1/[gamma]-H2AX DNA repair foci in human lymphocytes

Bioelectromagnetics — Mon, 06 Oct 2008 04:00:00 +0100

We have recently described frequency-dependent effects of mobile phone microwaves (MWs) of global system for mobile communication (GSM) on human lymphocytes from persons reporting hypersensitivity to electromagnetic fields and healthy persons. Contrary to GSM, universal global telecommunications system (UMTS) mobile phones emit wide-band MW signals. Hypothetically, UMTS MWs may result in higher biological effects compared to GSM signal because of eventual "effective" frequencies within the wideband. Here, we report for the first time that UMTS MWs affect chromatin and inhibit formation of DNA double-strand breaks co-localizing 53BP1/[gamma]-H2AX DNA repair foci in human lymphocytes from hypersensitive and healthy persons and confirm that effects of GSM MWs depend on carrier frequency. Rema...

Effect of long term exposure to 0.5 T static magnetic fields on growth and size of GH3 cells

Bioelectromagnetics — Mon, 06 Oct 2008 04:00:00 +0100

Brief exposure to moderate intensity static magnetic fields has been shown to produce a transient alteration in physiological function in a variety of biological systems, primarily those related to changes in intracellular Ca2+. In the present study GH3 cells were cultured during continuous exposure to a 0.5 T field, for periods of up to 5 weeks. Following a 1-week exposure, cell growth declined by 22% and returned to control levels in 1 week. This was not statistically significant but, with a 4-week exposure, a statistically significant decline in growth of 51% was observed and return to control levels did not occur for 4 weeks. Cell diameter, on the other hand, significantly increased following 3 weeks of exposure and did not return to control levels for 3 weeks after termination of expo...

Plasma membrane permeabilization by 60- and 600-ns electric pulses is determined by the absorbed dose

Bioelectromagnetics — Mon, 06 Oct 2008 04:00:00 +0100

We explored how the effect of plasma membrane permeabilization by nanosecond-duration electric pulses (nsEP) depends on the physical characteristics of exposure. The resting membrane resistance (Rm) and membrane potential (MP) were measured in cultured GH3 and CHO cells by conventional whole-cell patch-clamp technique. Intact cells were exposed to a single nsEP (60 or 600 ns duration, 0-22 kV/cm), followed by patch-clamp measurements after a 2-3 min delay. Consistent with earlier findings, nsEP caused long-lasting Rm decrease, accompanied by the loss of MP. The threshold for these effects was about 6 kV/cm for 60 ns pulses, and about 1 kV/cm for 600 ns pulses. Further analysis established that it was neither pulse duration nor the E-field amplitude per se, but the absorbed dose that determ...

GSM base stations: Short-term effects on well-being

Bioelectromagnetics — Sat, 20 Sep 2008 04:00:00 +0100

The purpose of this study was to examine the effects of short-term GSM (Global System for Mobile Communications) cellular phone base station RF-EMF (radiofrequency electromagnetic fields) exposure on psychological symptoms (good mood, alertness, calmness) as measured by a standardized well-being questionnaire. Fifty-seven participants were selected and randomly assigned to one of three different exposure scenarios. Each of those scenarios subjected participants to five 50-min exposure sessions, with only the first four relevant for the study of psychological symptoms. Three exposure levels were created by shielding devices in a field laboratory, which could be installed or removed during the breaks between sessions such that double-blinded conditions prevailed. The overall median power flu...

Space efficient system for whole-body exposure of unrestrained rats to 900 MHz electromagnetic fields

Bioelectromagnetics — Fri, 19 Sep 2008 04:00:00 +0100

The aim of this study was to design, implement and analyze a space-efficient setup for the whole-body exposure of unrestrained Wistar rats to radiofrequency (RF) electromagnetic fields at 900 MHz. The setup was used for 2 years in a cocarcinogenesis study and part of it for 5 weeks in a central nervous system (CNS) study. Up to 216 rats could be placed in separate cages in nine different exposure chambers on three racks requiring only 9 m2 of floor area (24 rats per m2). Chambers were radial transmission lines (RTL), where the rats could freely move in their cages where food and drinking water was provided ad libitum except during RF exposure periods. Dosimetrical analysis was based on FDTD computations with heterogeneous rat models and was validated with calorimetrical measurements carrie...

Mobile phone exposure and spatial memory

Bioelectromagnetics — Wed, 17 Sep 2008 04:00:00 +0100

This study investigated the effects of a h RF exposure (884 MHz) on spatial memory and learning, using a double-blind repeated measures design. The exposure was designed to mimic that experienced during a real-life mobile phone conversation. The design maximized the exposure to the left hemisphere. The average exposure was peak spatial specific absorption rate (psSAR10g) of 1.4 W/kg. The primary outcome measure was a "virtual" spatial navigation task modeled after the commonly used and validated Morris Water Maze. The distance traveled on each trial and the amount of improvement across trials (i.e., learning) were used as dependent variables. The participants were daily mobile phone users, with and without symptoms attributed to regular mobile phone use. Results revealed a main effect of R...

Effects of short-term W-CDMA mobile phone base station exposure on women with or without mobile phone related symptoms

Bioelectromagnetics — Wed, 10 Sep 2008 04:00:00 +0100

In conclusion, we found no evidence of any causal link between hypersensitivity symptoms and exposure to EMF from base stations. Bioelectromagnetics © 2008 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Influence of blood flow and millimeter wave exposure on skin temperature in different thermal models

Bioelectromagnetics — Mon, 08 Sep 2008 04:00:00 +0100

Recently we showed that the Pennes bioheat transfer equation was not adequate to quantify mm wave heating of the skin at high blood flow rates. To do so, it is necessary to incorporate an "effective" thermal conductivity to obtain a hybrid bioheat equation (HBHE). The main aim of this study was to determine the relationship between non-specific tissue blood flow in a homogeneous unilayer model and dermal blood flow in multilayer models providing that the skin surface temperatures before and following mm wave exposure were the same. This knowledge could be used to develop multilayer models based on the fitting parameters obtained with the homogeneous tissue models. We tested four tissue models consisting of 1-4 layers and applied the one-dimensional steady-state HBHE. To understand the role...

Reminiscences of a journeyman scientist: Studies of thermoregulation in non-human primates and humans

Bioelectromagnetics — Mon, 08 Sep 2008 04:00:00 +0100

After graduating from Mount Holyoke College in 1948 where I majored in experimental psychology I worked at the College for 2 years with the Johns Hopkins Thermophysiological Unit. My graduate work later at the University of Wisconsin, centering on sensory psychology, culminated in my 1955 PhD thesis on human dark adaptation. I continued work in sensory psychology later with Neal Miller at Yale and then moved to the John B. Pierce Foundation - a Yale affiliate - where I began the studies of thermoregulation that constitute the center of my scientific career. Those studies were largely - later wholly - conducted using microwave energy as a thermal load and were thus published in Bioelectromagnetics even as I played an active role in the Bioelectromagnetics Society. In the beginning this work...

Investigations of a simulated geomagnetic field experienced by the international space station on attentional performance

Bioelectromagnetics — Thu, 21 Aug 2008 04:00:00 +0100

We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field also affects cognitive functions. Twenty-four volunteers participated in the study, 12 exposed to the natural geomagnetic field and 12 to the magnetic field encountered by ISS. The test protocol consisted of a set of eight tests chosen from a computerized test battery for the assessment of attentional performance. The duration of exposure was 90 min. No effect of exposure to ISS magnetic field was observed on attentional performance. Bioelectromagnetics. © 2008 Wiley-Liss, In...

Eleanor R. Adair: 2007 D'Arsonval Award recipient

Bioelectromagnetics — Thu, 07 Aug 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

A newly designed and constructed 20 kHz magnetic field exposure facility for in vivo study

Bioelectromagnetics — Fri, 01 Aug 2008 04:00:00 +0100

Exposure to man-made electromagnetic fields has increased over the past century. As a result of exposure to these fields, concerns have been raised regarding the relationship between electromagnetic fields and human health. Interest in the biological and health effects of intermediate frequency (IF) magnetic fields has grown recently because of the increase in public concern. In order to investigate whether IF magnetic fields have biological effects, we have developed a 20 kHz (IF) magnetic field exposure system for in vivo studies. The exposure facility was designed to study the biological effects of IF magnetic field on laboratory animals. The facility consists of a 9 m × 9 m × 5 m high room containing seven separate rooms including a 5.3 m × 4.5 m × 3 m high specific-pathogen free e...

Security considerations in blinded exposure experiments using electromagnetic waves

Bioelectromagnetics — Thu, 31 Jul 2008 04:00:00 +0100

Whether exposure to electromagnetic fields well below accepted exposure limits has a cytogenetic effect on human cells has long been debated. It is widely published and generally accepted that the exposure unit invariably used in these experiments is capable of providing blinded exposure conditions. The following short report illustrates, however, that exposure conditions might not always be as effectively masked as is generally assumed. Bioelectromagnetics © 2008 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Changes in human EEG alpha activity following exposure to two different pulsed magnetic field sequences

Bioelectromagnetics — Mon, 28 Jul 2008 04:00:00 +0100

This study supports our previous observation of EEG changes after 5 min pulsed ELF MF exposure. The results of this study are also consistent with existing EEG experiments of ELF MF and mobile phone effects upon the brain. Bioelectromagnetics, 2008. © 2008 Wiley-Liss, Inc. (Source: Bioelectromagnetics)

Best paper award and OnlineOpen access

Bioelectromagnetics — Tue, 15 Jul 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Lung cancer A549 cells migrate directionally in DC electric fields with polarized and activated EGFRs

Bioelectromagnetics — Fri, 11 Jul 2008 04:00:00 +0100

Endogenous direct-current electric fields (dcEFs) occur in vivo in the form of epithelial transcellular potentials or neuronal field potentials. A variety of cells respond to dcEFs by migrating directionally, and this is termed galvanotaxis. The mechanism by which dcEFs direct cell movement, however, is not yet understood, and the effects on lung cancer cells are entirely unknown. We demonstrated that cultured human lung adenocarcinoma A549 cells migrate toward the cathode in applied dcEFs at 3 V/cm. Fluorescence microscopy showed that both epidermal growth factor receptors (EGFRs) and F-actin are polarized to the cathode. EGFR inhibitors, cetuximab and AG1478, reduced the migration rate and directed motility in dcEFs. Western blots showed that ERK and AKT signaling pathways were prominent...

Recent advances in research relevant to electric and magnetic field exposure guidelines

Bioelectromagnetics — Thu, 10 Jul 2008 04:00:00 +0100

Limits on exposures to extremely low-frequency electric fields, magnetic fields and contact currents, designated as voluntary guidelines or standards by several organizations worldwide, are specified so as to minimize the possibility of neural stimulation. The limits, which we refer to as guidelines, derive from "basic restrictions" either on electric fields or current density within tissue, or on avoidance of annoying or startling interactions that may be experienced with spark discharge or contact current. Further, the guidelines specify more conservative permissible doses and exposure levels for the general public than for exposures in controlled environments, which most typically involve occupational settings. In 2001 we published an update on guideline science. This paper covers more ...

Prolonged weakening of the geomagnetic field (GMF) affects the immune system of rats

Bioelectromagnetics — Thu, 19 Jun 2008 04:00:00 +0100

The aim of this study was to find out how a long-term shielding of the geomagnetic field (GMF) affected the immune system of rats. Male and female Wistar rats were kept up to an age of 2 months in a natural GMF (about 37 µT). Afterwards, the rats were divided into four groups (males and females separately): control rats were maintained in ambient GMF, while experimental animals were housed under conditions of a weakened GMF (below 12 µT) achieved with steel cages. After 6 months, the rats were sacrificed by decapitation. Spleens and thymuses were isolated and weighed. Peritoneal cells were eluted and cultured in vitro to study their ability to produce nitric oxide (NO) and to synthesize superoxide anion (O-2), important microbicidal molecules of macrophages. The number of macrophages was...

Analysis of individual- and school-level clustering of power frequency magnetic fields

Bioelectromagnetics — Wed, 11 Jun 2008 04:00:00 +0100

This study reports the continuous 8-h monitoring of data on extremely low-frequency magnetic fields (ELF-MF) relating to 14 children and 35 teachers in 11 elementary schools in Northern Taiwan. It was anticipated that the subjects in two of these campuses would have elevated exposure to ELF-MF as a result of their close proximity to high-voltage (161 kilo-Volt, kV) power lines. The results of our analysis reveal that in those schools with high-voltage power lines running through the campuses, the mean ELF-MF exposure level (0.38 ± 0.51 micro-Tesla (µT), or 0.15, 0.25 and 0.44 µT at the respective 25th, 50th and 75th percentiles) was higher than the mean ELF-MF exposure level for campuses situated far away from such high-voltage power lines (0.14 ± 0.27 µT, or 0.04, 0.06 and 0.10 µT a...

Editor's Note

Bioelectromagnetics — Tue, 03 Jun 2008 04:00:00 +0100

No Abstract. (Source: Bioelectromagnetics)

Reducing overestimation in reported mobile phone use associated with epidemiological studies

Bioelectromagnetics — Mon, 02 Jun 2008 04:00:00 +0100

Case-control studies of mobile phones are commonly based on retrospective, self-reported exposure information, which are often characterized as involving substantial uncertainty concerning data validity. We assessed the validity of self-reported mobile phone use and developed a statistical model to account for the over-reporting of exposure. We collected information on mobile phone use from 70 volunteers using two sources of data: self-report in an interview and network operator records. We used regression models to obtain bias-corrected estimates of exposure. A correlation coefficient of 0.71 was obtained between the self-reported and the network operators' data on average calling time (log-transformed minutes per month). A simple linear regression model, where the duration of calls acqui...

Effects of strong static magnetic fields used in magnetic resonance imaging on insulin-secreting cells

Bioelectromagnetics — Mon, 02 Jun 2008 04:00:00 +0100

The magnetic flux density of MRI for clinical diagnosis has been steadily increasing. However, there remains very little biological data regarding the effect of strong static magnetic fields (SMFs) on human health. To evaluate the effects of strong SMFs on biological systems, we cultured insulin-secreting cells under exposure to sham and SMF conditions (3-10 T of magnetic flux density, and 0-41.7 T/m of magnetic field gradient) for 0.5 or 1 h, and analyzed insulin secretion, mRNA expression, glucose-stimulated insulin secretion, insulin content, cell proliferation and cell number. Exposure to SMF with a high magnetic field gradient for 1 h significantly increased insulin secretion and insulin 1 mRNA expression. Exposure to SMF with a high magnetic flux density for 0.5 h significantly enhan...

The effects of inverter magnetic fields on early seed germination of mung beans

Bioelectromagnetics — Mon, 02 Jun 2008 04:00:00 +0100

This study aims to assess the effects of magnetic fields generated by inverter systems on the early growth of plants using mung beans as an example. In the experiment, an inverter which can produce sinusoidal pulsed width modulation (SPWM) voltages was used to drive 3 specially made circular coils and an AC motor. Six SPWM voltages with different fundamental frequencies (10, 20, 30, 40, 50, and 60 Hz) set on the inverter drive the circuit to produce the specific kinds of MFs. The results indicate that the magnetic field induced by a 20 or 60 Hz SPWM voltage has an enhancing effect on the early growth of mung beans, but the magnetic fields induced by SPWM voltages of other frequencies (30, 40, and 50 Hz) have an inhibitory effect, especially at 50 Hz. Bioelectromagnetics. 2008 Wiley-Liss, I...

The Influence of a gradient static magnetic field on an unstirred Belousov-Zhabotinsky reaction

Bioelectromagnetics — Sat, 31 May 2008 04:00:00 +0100

It is believed that static magnetic fields (SMF) cannot affect the pattern formation of the Belousov-Zhabotinsky (BZ) reaction, which has been frequently studied as a simplified experimental model of a nonequilibrium open system, because SMF produces no induced current and the magnetic force of SMF far below 1 T is too low to expect the effects on electrons in the BZ reaction. In the present study, we examined whether the velocity of chemical waves in the unstirred BZ reaction can be affected by a moderate-intensity SMF exposure depending on the spatial magnetic gradient. The SMF was generated by a parallel pair of attracting rectangular NdFeB magnets positioned opposite each other. The respective maximum values of magnetic flux density (Bmax), magnetic flux gradient (Gmax), and the magnet...

The effect of high strength static magnetic fields and ionizing radiation on gene expression and DNA damage in Caenorhabditis elegans

Bioelectromagnetics — Fri, 30 May 2008 04:00:00 +0100

Magnetic resonance imaging with high static magnetic fields (SMFs) has become widely used for medical imaging purposes because SMFs cause fewer genotoxic side effects than ionizing radiation (IR). However, the effect of exposure to high SMFs on global transcription is little understood. We demonstrate that genes involved in motor activity, actin binding, cell adhesion, and cuticles are transiently and specifically induced following exposure to 3 or 5 T SMF in the experimental model metazoan Caenorhabditis elegans. In addition, transient induction of hsp12 family genes was observed after SMF exposure. The small-heat shock protein gene hsp16 was also induced but to a much lesser extent, and the LacZ-stained population of hsp-16.1::lacZ transgenic worms did not significantly increase after ex...

Extremely low frequency electromagnetic fields (ELF-EMFs) induce in vitro angiogenesis process in human endothelial cells

Bioelectromagnetics — Fri, 30 May 2008 04:00:00 +0100

Effects of extremely low frequency (ELF) electromagnetic fields (EMFs) on activation of angiogenesis were analysed using cultured umbilical human vein endothelial cells (HUVECs). The cultures were exposed to a sinusoidal EMF to intensity of 1 mT, 50 Hz for up to 12 h. EMFs increased the degree of endothelial cell proliferation and tubule formation, coupled by an acceleration in the process of wound healing. Since this process is physiologically accompanied by a large modification in the structural organization of actin and focal adhesions, we analyzed the rearrangement of some cytoskeleton elements demonstrating a major reorganization of the fibres and of the focal adhesion complexes after EMF exposure. Finally, Western blot analysis revealed a significant increase in phosphorylation as we...

Spindle disturbances in human-hamster hybrid (AL) cells induced by mobile communication frequency range signals

Bioelectromagnetics — Fri, 30 May 2008 04:00:00 +0100

The production of spindle disturbances in FC2 cells, a human-hamster hybrid (AL) cell line, by non-ionizing radiation was studied using an electromagnetic field with a field strength of 90 V/m at a frequency of 835 MHz. Due to the given experimental conditions slide flask cultures were exposed at room temperature in a µTEM (transversal electromagnetic field) cell, which allows optimal experimental conditions for small samples of biological material. Numerical calculations suggest that specific absorption rates of up to 60 mW/kg are reached for maximum field exposure. All exposure field parameters - either measured or calculable - are precisely defined and, for the first time, traceable to the standards of the SI system of physical units. Compared with co-incident negative controls, the re...

Acute radio frequency irradiation does not affect cell cycle, cellular migration, and invasion

Bioelectromagnetics — Fri, 30 May 2008 04:00:00 +0100

This study was conducted to determine whether RF radiation exposure exerts detectable effects on cell cycle distribution, cellular invasion, and migration. NIH3T3 mouse fibroblasts were exposed to 849 MHz of RF radiation at average SAR values of 2 or 10 W/kg for either 1 h, or for 1 h per day for 3 days. During the exposure period, the temperature in the exposure chamber was maintained isothermally by circulating water throughout the cavity. Cell cycle distribution was analyzed at 24 and 48 h after exposure, by flow cytometry. We detected no statistically significant differences between the sham-exposed and RF radiation-exposed cells. Cellular invasion and migration were assessed by in vitro Matrigel invasion and Transwell migration assays. The RF radiation-exposed groups evidenced no sign...