Abstract：
:To characterize the inhibitory effect of a static magnetic field, action potentials (AP) were elicited by intracellular application of 1 ms depolarizing current pulses of constant amplitude to the somata of adult mouse dorsal root ganglion neurons in monolayer dissociated cell culture. During the control period, < 5% of stimuli failed to elicit AP. During exposure to an approximately 11 mT static magnetic field at the cell position produced by an array of four permanent center-charged neodymium magnets of alternating polarity (MAG-4A), 66% of stimuli failed to elicit AP. The number of failures was maximal after about 200-250 s in the field and returned gradually to baseline over 400-600 s. A direct or indirect effect on the conformation of AP generating sodium channels could account for these results because 1) failure was preceded often by reduction of maximal rate of rise, an indirect measure of sodium current; 2) recovery was significantly prolonged in more than one-half of neurons that were not stimulated during exposure to the MAG-4A field; and 3) resting membrane potential, input resistance, and chronaxie were unaffected by the field. The effect was diminished or prevented by moving the MAG-4A array along the X or Z axis away from the neuron under study and by increasing the distance between magnets in the XY plane. Reduction of AP firing during exposure to the approximately 0.1 mT field produced by a MAG-4A array of micromagnets was about the same as that produced by a MAG-4A array of the large magnets above. The approximately 28 mT field produced at cell position by two magnets of alternating polarity and the approximately 88 mT field produced by a single magnet had no significant effect on AP firing. These findings suggest that field strength alone cannot account for AP blockade.
journal_name
Bioelectromagneticsjournal_title
Bioelectromagneticsauthors
McLean MJ,Holcomb RR,Wamil AW,Pickett JD,Cavopol AVdoi
10.1002/bem.2250160108subject
Has Abstractpub_date
1995-01-01 00:00:00pages
20-32issue
1eissn
0197-8462issn
1521-186Xjournal_volume
16pub_type
杂志文章abstract：:Data are presented on ankle-specific SARs and foot currents as a function of strengths of radio-frequency electromagnetic fields encountered by operators of dielectric heaters. The determination of foot currents was based on near-field exposures in which reactive coupling dominates, and which can result in substantial...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250130204
更新日期：1992-01-01 00:00:00
abstract：:As a result of ischaemia/reperfusion, massive generation of reactive oxygen species occurs, followed by decreased activity of antioxidant enzymes. Extremely low frequency electromagnetic fields (ELF-EMF) can modulate oxidative stress, but there are no clinical antioxidant studies in brain stroke patients. The aim of o...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.22055
更新日期：2017-07-01 00:00:00
abstract：: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 pr...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20568
更新日期：2010-07-01 00:00:00
abstract：:This study was undertaken to investigate whether power frequency magnetic fields can affect the kinetics of cell cycle progression in exposed human cells. To achieve this, cultures of normal human fibroblasts were synchronised in the G(0) phase of the cell cycle and exposed to 50 Hz magnetic fields at a range of flux ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：
更新日期：1999-10-01 00:00:00
abstract：:Stress proteins are important in protection during cardiac ischemia/reperfusion (cessation and return of blood flow) and are reportedly induced by electromagnetic (EM) fields. This suggests a possible ischemia protection role for EM exposures. To test this, chick embryos (96 h) were exposed to 60 Hz magnetic fields pr...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/(sici)1521-186x(1998)19:8<498::aid-bem8>3.
更新日期：1998-01-01 00:00:00
abstract：:In epidemiological studies of electromagnetic fields and health effects, exposure classification is crucial. There is no generally accepted biophysical interaction mechanism, but many studies are based on the hypothesis of a causal relationship with the strength of magnetic field. Some definition of the magnitude of e...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/(SICI)1521-186X(1996)17:3<209::AID-BEM6>3.
更新日期：1996-01-01 00:00:00
abstract：:Nanosecond electric pulse (nsEP) exposure generates an array of physiological effects. The extent of these effects is impacted by whether the nsEP is a unipolar (UP) or bipolar (BP) exposure. A 600 ns pulse can generate 71% more YO-PRO-1 uptake compared to a 600 ns + 600 ns pulse exposure. This observation is termed "...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.22134
更新日期：2018-09-01 00:00:00
abstract：:This report describes some experimental measurements of the internal field levels induced within isolated chick-forebrains irradiated at 50, 147, and 450 MHz, under essentially the same conditions as those used in the in vitro calcium-ion efflux experiments. Ratios of incident power at 50/147 MHz and 147/450 MHz that ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250050302
更新日期：1984-01-01 00:00:00
abstract：:Introduction of genetic material into muscle tissue has been extensively researched, including isolation and in vitro expansion of primary myoblasts as a potential source of cells for skeletal and heart muscle tissue engineering applications. In this study, we optimized the electroporation protocol for introduction of...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.21936
更新日期：2015-12-01 00:00:00
abstract：:A system is described that uses an oscillating magnetic field to produce power-frequency electric fields with strengths in excess of those produced in an animal or human standing under a high-voltage electric-power transmission line. In contrast to other types of exposure systems capable of generating fields of this s...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250050202
更新日期：1984-01-01 00:00:00
abstract：:Sixteen pregnant Holstein heifers weighing 521 +/- 46 kg, at 3.3 +/- 0.7 months of gestation and 2.2 +/- 2.0 months of age were confined to wooden metabolism cages and were exposed to a vertical electric field (EF) of 10.0 +/- 0.4 kV/m and an artificial light cycle of 12 h light-12 h dark. The heifers were divided int...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20020
更新日期：2004-05-01 00:00:00
abstract：:To be able to correlate real time membrane potential or ion flux changes with further downstream gene transcription responses due to extremely low frequency (ELF) electromagnetic field (EMF) exposure, we devised an experimental system consisting of a pair of symmetric circular coils. This system can be used on an inve...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.10151
更新日期：2004-01-01 00:00:00
abstract：:The aim of the present study was to identify the effects of a static magnetic field (SMF) on rat brain structures that control autonomic functions, specifically heart rate and heart rhythmicity. The experiments were carried out on 44 male Wistar rats under ketamine-xylazine anesthesia. SMF was induced using samarium-c...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.10186
更新日期：2004-04-01 00:00:00
abstract：:Experiments were conducted to see whether the cellular response to electromagnetic (EM) fields occurs through a detection process involving temporal sensing. L929 cells were exposed to 60 Hz magnetic fields and the enhancement of ornithine decarboxylase (ODC) activity was measured to determine cellular response to the...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/(sici)1521-186x(1997)18:5<388::aid-bem6>3.
更新日期：1997-01-01 00:00:00
abstract：:Measurements have been made of vector current densities induced by vertical, uniform, 60-Hz electric fields in the torsos of homogeneous models of swine and rats. The observed data were a strong function of the five grounding configurations invested: all four feet grounded, only front feet grounded, only rear feet gro...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250090102
更新日期：1988-01-01 00:00:00
abstract：:Serial longitudinal and transverse sections were prepared from roots of Cucumis sativus and Cucurbita maxima that had been exposed/sham-exposed to 60-Hz electric fields for 0-2 days. Field exposures were selected to produce a 10-20% or a 70-80% growth inhibition in whole roots of both species. Cortical cell length and...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250080108
更新日期：1987-01-01 00:00:00
abstract：:The effects of exposure to clinical magnetic resonance imaging (MRI) on analgesia induced by the mu opiate agonist, fentanyl, was examined in mice. During the dark period, adult male mice were exposed for 23.2 min to the time-varying (0.6 T/sec) magnetic field (TVMF) component of the MRI procedure. Following this expo...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250090208
更新日期：1988-01-01 00:00:00
abstract：:Ejaculated, density purified, human spermatozoa were exposed to pulsed 900 MHz GSM mobile phone radiation at two specific absorption rate levels (SAR 2.0 and 5.7 W/kg) and compared with controls over time. Change in sperm mitochondrial membrane potential was analysed using flow cytometry. Sperm motility was determined...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20390
更新日期：2008-05-01 00:00:00
abstract：:Conductive nanoparticles may enhance tissue heating during radiofrequency (RF) irradiation. Specific absorption rate (SAR) is known to rise with the electrical conductivity of tissue. However, no studies to date have measured the relationship between complex permittivity and nanoparticle concentration in tissue-like s...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20595
更新日期：2010-12-01 00:00:00
abstract：:The widespread use of mobile phones and Wi-Fi-based communication devices makes exposure to radiofrequency electromagnetic fields (RF-EMF) unavoidable. Previous experiments have revealed the tumor-promoting effects of non-ionizing RF-EMF in adult carcinogen-treated mice in utero. To extend these investigations, we tes...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.22301
更新日期：2020-12-01 00:00:00
abstract：:In the last few years, significant developments have taken place in the field of Wireless Local Area Networks (WLAN), and the popularity of portable devices supporting Wireless Fidelity (Wi-Fi) is continuously growing. At the same time, the number of Active Implanted Medical Devices (AIMD) being placed in patients is ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20601
更新日期：2010-10-01 00:00:00
abstract：:Studies have evaluated the electroencephalography (EEG) of humans and laboratory animals during and after Radiofrequency (RF) exposures. Effects of RF exposure on the blood-brain barrier (BBB) have been generally accepted for exposures that are thermalizing. Low level exposures that report alterations of the BBB remai...
journal_title：Bioelectromagnetics
pub_type： 杂志文章,评审
doi：10.1002/bem.10179
更新日期：2003-01-01 00:00:00
abstract：:Rat PC12 pheochromocytoma cells have been treated with nerve growth factor and then exposed to athermal levels of a packet-modulated radiofrequency field at 836.55 MHz. This signal was produced by a prototype time-domain multiple-access (TDMA) transmitter that conforms to the North American digital cellular telephone ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/(sici)1521-186x(1997)18:3<223::aid-bem4>3.
更新日期：1997-01-01 00:00:00
abstract：:The impedance spectroscopy technique (IST) was used for studying the effect of a 0.5 T magnetic field on the electrical properties of whole human blood. A Solartron SI 1260 spectrometer was used to measure the impedance spectra of magnetic field exposed blood samples compared to non-exposed samples. An equivalent elec...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.20132
更新日期：2005-10-01 00:00:00
abstract：:We have shown that 50 Hz sinusoidal magnetic fields within the 5-10 microTesla (microT) rms range cause an intensity-dependent reduction in nerve growth factor (NGF) stimulation of neurite outgrowth (NO) in PC-12 cells. Here we report on the frequency dependence of this response over the 15-70 Hz range at 5 Hz interva...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250160607
更新日期：1995-01-01 00:00:00
abstract：:No causal treatment for chemotherapy-induced peripheral neuropathy (CIPN) is known. Therefore, there is an urgent need to develop a therapy for CIPN. Only scarce clinical data are available concerning magnetic field therapy (MFT) in this context. We conducted a unicentric, randomized, double-blind, placebo-controlled ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章,随机对照试验
doi：10.1002/bem.22005
更新日期：2017-02-01 00:00:00
abstract：:Fertile eggs of the Coturnix quail were exposed twice a day for 30 min to 2.45-GHz continuous wave radiation at power densities of 25 or 50 mW cm-2 throughout the 17-day incubation period. Other eggs were exposed to 20 degrees C or 24 degrees C temperatures twice daily. Repeated exposures to 20 degrees C, 24 degrees C...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250060307
更新日期：1985-01-01 00:00:00
abstract：:Laboratory measurements of electric fields have been carried out around examples of smart meter devices used in Great Britain. The aim was to quantify exposure of people to radiofrequency signals emitted from smart meter devices operating at 2.4 GHz, and then to compare this with international (ICNIRP) health-related ...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.22044
更新日期：2017-05-01 00:00:00
abstract：:The objective of this study was to develop a model for testing various hypotheses concerning possible mechanisms whereby electromagnetic fields might induce suppression of nighttime melatonin production in rodents. A published method for digesting freshly obtained pineal glands to the single cell level was modified, y...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：:The treatment of long-term, stable para- and quadriplegics with pulsed electrical stimulation for pain control resulted in, anecdotally, a significant number of these individuals showing increased motor function as well as sensory awareness. This small pilot study was conducted in order to assess the hypothesis that p...
journal_title：Bioelectromagnetics
pub_type： 杂志文章
doi：10.1002/bem.2250080206
更新日期：1987-01-01 00:00:00
