Abstract:
:Little is known about the influence of magnetic fields on growth of primitive eukaryotes such as the ciliate Paramecium. The latter are known to exhibit interesting characteristics such as electrotaxis, gravitaxis, and membrane excitability not commonly encountered in higher organisms. This preliminary study reports the effects of static magnetic fields on growth of Paramecium caudatum. The microorganisms were either permanently or 24 h on-and-off exposed to North and South polarity magnetic fields of average field gradient 4.3 T/m, for a period of 96 h. The growth rate and lag phase of all exposed populations were not significantly different from control ones exposed to normal geomagnetic field (P > .05). However, a significant negative shift in t(max) (time taken for maximum growth) of 10.5%-12.2% and a significant decrease (P < .05) in population size of 10.2%-15.1% during the 96 h of experimental conditions were recorded for exposed populations compared to control. Our results suggest that magnetic fields, irrespective of polarity and exposure period reduce Paramecium growth by triggering early senescence of the population. The mechanisms underlying the small changes in population growth are unknown at this level, but various hypotheses have been suggested, including disorganization of swimming patterns resulting from (i) changes in cell membrane electric potential due to high speed movement through a gradient magnetic field and (ii) thermodynamic effect of anisotropic magnetic energies on cell membrane components affecting functioning of calcium channels. Altered swimming movements could in turn affect highly orchestrated processes such as conjugation, essential for survival of the organisms during development of adverse environmental conditions as thought to occur in the closed culture system used in this study.
journal_name
Bioelectromagneticsjournal_title
Bioelectromagneticsauthors
Elahee KB,Poinapen Ddoi
10.1002/bem.20172subject
Has Abstractpub_date
2006-01-01 00:00:00pages
26-34issue
1eissn
0197-8462issn
1521-186Xjournal_volume
27pub_type
杂志文章abstract::Electric fields induced in a conductive body by the magnetic field of a current-carrying wire were analyzed theoretically and experimentally to assess the dosimetric importance of highly nonuniform, field-exposure conditions. Experimentation revealed that a 60-Hz magnetic field was inversely proportional to the radius...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250130305
更新日期:1992-01-01 00:00:00
abstract::Sprague-Dawley male rats, maintained in a 14:10 h light:dark cycle were exposed for 30 days (starting at 56 days of age) to a 65 kV/m, 60 Hz electric field or to a sham field for 20 h/day beginning at dark onset. Pineal N-acetyltransferase (NAT), hydroxy-indole-o-methyl transferase (HIOMT), and melatonin as well as se...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250150506
更新日期:1994-01-01 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::Magnetic resonance (MR)-based electrical impedance tomography (MREIT) is a widely used imaging technique that provides high-resolution conductivity images at DC or below the 1 kHz frequency range. Using an MR scanner, this technique injects imaging currents into the human body and measures induced internal magnetic fl...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.21852
更新日期:2014-07-01 00:00:00
abstract::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 ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20438
更新日期:2009-01-01 00:00:00
abstract::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 tra...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20507
更新日期:2009-10-01 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 temporal variation of a static electric field inside an animal cage was investigated with a newly developed small, simple field meter. The field inside the cage was found to be highly dependent on the surface conductivity of the dielectric material. As the surface of the cage became dirty because of animal occupan...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250020410
更新日期:1981-01-01 00:00:00
abstract::The constant exposure of modern society to extremely low frequency magnetic fields (ELF-MF) has raised considerable concerns about the potential risks to male reproduction. However, the epidemiological and experimental data remain contradictory and inconclusive. In the present study, we investigated the effects of 50 ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.21816
更新日期:2014-01-01 00:00:00
abstract::Previously, we have reported that exposure to 50 Hz coherent sinusoidal magnetic fields (MF) for 24 h inhibits gap junction intercellular communication (GJIC) in mammalian cells at an intensity of 0.4 mT and enhances the inhibition effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) at 0.2 mT. In the present study, w...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20207
更新日期:2006-05-01 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::The effect of magnetized physiological solution (MPS) on isolated, perfused snail heart muscle contractility, (45)Ca uptake and intracellular level of cAMP, and cGMP was studied. The existence of the relaxing effect of MPS on heart muscle at room temperature (22 degrees C) and its absence in cold medium (4 degrees C) ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20145
更新日期:2005-12-01 00:00:00
abstract::The US National Electrical Code's (NEC) requirement to ground a home's electrical service to the residential water line results in a voltage between the water line and earth, V W-E. The voltage may result from ground return current that flows into the earth via the water line or from inductive effects from other sourc...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20033
更新日期:2004-10-01 00:00:00
abstract::There are large disparities between basic restrictions for exposure to extremely low-frequency (0-3 kHz) Electric and Magnetic Fields set by two major international bodies. Both bodies agree that these basic restrictions should prevent neuro-stimulatory effects: the retinal phosphene at frequencies up to a few hundred...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20412
更新日期:2008-09-01 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::C57/B1 mice were exposed during pregnancy (gestation days 0-19) to a 20 kHz magnetic field (MF). The asymmetric sawtooth-waveform magnetic field in the exposed racks had a flux density of 15 microT (peak to peak). After 19 days, the exposure was terminated, and the mice were housed individually under normal laboratory...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250160409
更新日期:1995-01-01 00:00:00
abstract::A retrospective study on reproductive hazards was performed among 542 employees at Swedish power plants. Questionnaires were answered by 89% of the employees. Data on pregnancies were checked by studying hospital case records. There was a statistically significant, decreased frequency of "normal" pregnancy outcome, al...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250040109
更新日期:1983-01-01 00:00:00
abstract::We have previously demonstrated that exposure of Chinese hamster lung (CHL) cells to 50 Hz magnetic fields (MFs) and/or 12-O-tetradecanoylphorbol-3-acetate (TPA)-inhibited gap junctional intercellular communication (GJIC). To explore and compare the mechanisms of GJIC inhibition induced by extremely low frequency (ELF...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.10070
更新日期:2003-02-01 00:00:00
abstract::The present study examined the effect on rat cortical synaptosomes of a 2 h exposure to 50-Hz electromagnetic fields (EMFs) with a peak magnetic field of 2 mT. We measured modifications of synaptosomal mitochondrial respiration rate, ATP production, membrane potential, intrasynaptosomal Ca(2+) concentration and free i...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20322
更新日期:2007-09-01 00:00:00
abstract::The objective of this study was to investigate if persons with implantable medical devices are intrinsically protected by the current electromagnetic safety guidelines. For inter-laboratory comparisons, the U.S. Food and Drug Administration has defined a generic implant as consisting of an insulated wire with noninsul...
journal_title:Bioelectromagnetics
pub_type: 临床试验,杂志文章
doi:10.1002/bem.21695
更新日期:2012-07-01 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::The potential use of multiple-frequency-band radiometry as a means of noninvasive sensing of one-dimensional temperature profiles is presented in this communication. The radiative energy transfer equation is solved numerically. Ideal-condition thermal noise spectra and distributions of received energy, associated with...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250060406
更新日期:1985-01-01 00:00:00
abstract::The controversy over the possible association between magnetic field exposure and childhood leukemia has led several researchers to summarize the literature using meta-analysis. This paper reviews these previous meta-analyses and extends them by adding results from four studies published since the most recent analysis...
journal_title:Bioelectromagnetics
pub_type: 杂志文章,meta分析
doi:10.1002/1521-186x(2001)22:5+<::aid-bem1026>3.3.co;
更新日期:2001-01-01 00:00:00
abstract::In an hypothesis-generating case-control study of amyotrophic lateral sclerosis, lifetime occupational histories were obtained. The patients (n = 28) were clinic based. The occupational exposure of interest in this report is electromagnetic fields (EMFs). This is the first and so far the only exposure analyzed in this...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/(sici)1521-186x(1997)18:1<28::aid-bem6>3.0
更新日期:1997-01-01 00:00:00
abstract::Magnetic fields (60 Hz) of 1.5 and 80 microT caused a significant reduction in the weight of Drosophila melanogaster. Moreover, fruit flies in an 80 microT field showed lower developmental stability than either those in a 0 or 1.5 microT field. Developmental instability was measured by fluctuating asymmetry and freque...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:
更新日期:2000-09-01 00:00:00
abstract::Reports that low-intensity microwave radiation induces heat-shock reporter gene expression in the nematode, Caenorhabditis elegans, have recently been reinterpreted as a subtle thermal effect caused by slight heating. This study used a microwave exposure system (1.0 GHz, 0.5 W power input; SAR 0.9-3 mW kg(-1) for 6-we...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20515
更新日期:2009-12-01 00:00:00
abstract::The accurate and valid measurement of personal exposure to magnetic fields poses a major challenge for epidemiologic studies. When considering the various methods to assess exposure, it is unclear which measures are most relevant for studies of human disease, if any. Given these uncertainties, the Electromagnetic Fiel...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:
更新日期:1999-12-01 00:00:00
abstract::Chemical and bacterial synthesis of a thermochemiluminescent polymer known as diazoluminomelanin (DALM) has been previously reported. This paper focuses on the intracellular synthesis of aminomelanin (AM) in mammalian cell lines and subsequent DALM synthesis from this core molecule. B16 melanoma cells, HL-60 myeloid l...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250150406
更新日期:1994-01-01 00:00:00
abstract::Mobile phone use in the United Kingdom and other countries has risen steeply since the early 1990's when the first digital mobile phones were introduced. There is an ongoing controversy about whether radio frequency (RF) exposure from mobile phones increases the risk of brain cancer. However, given the widespread use ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20648
更新日期:2011-07-01 00:00:00
abstract::Our previous studies showed that extremely low frequency magnetic fields (ELF-MFs) inhibited tumor growth and change proportion of splenic regulatory T cells (Treg cells). Here, we focus on the effect of ELF-MFs on lung metastatic melanoma mouse model and the regulatory mechanism of ELF-MFs on the differentiation of T...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.21954
更新日期:2016-02-01 00:00:00