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At least 1,369 records · Page 76Linked to original sources
PubMed1999

Impairment of depth perception in multiple sclerosis is improved by treatment with AC pulsed electromagnetic fields.

Multiple sclerosis (MS) is associated with postural instability and an increased risk of falling which is facilitated by a variety of factors including diminished visual acuity, diplopia, ataxia, apraxia of gait, and peripheral neuropathy. Deficient binocular depth perception may also contribute to a higher incidence of postural instability and falling in these patients who, for example, find it an extremely difficult task to walk on uneven ground, over curbs, or up and down steps. I report a 51 year old woman with secondary progressive MS who experienced difficulties with binocular depth perception resulting in frequent falls and injuries. Deficient depth perception was demonstrated also on spontaneous drawing of a cube. Following a series of transcranial treatments with AC pulsed electromagnetic fields (EMFs) of 7,5 picotesla flux density, the patient experienced a major improvement in depth perception which was evident particularly on ascending and descending stairs. These clinical changes were associated with an improvement in spatial organization and depth perception on drawing a cube. These findings suggest that in MS impairment of depth perception, which is encoded in the primary visual cortex (area 17) and visual association cortex (areas 18 and 19), may be improved by administration of AC pulsed EMFs of picotesla flux density. The primary visual cortex is densely innervated by serotonergic neurons which modulate visual information processing. Cerebral serotonin concentrations are diminished in MS patients and at least some aspects of deficient depth perception in MS may be related to dysfunction of serotonergic transmission in the primary visual cortex. It is suggested that transcranial AC pulsed applications of EMFs improve depth perception partly by augmenting serotonergic transmission in the visual cortex.

Depth Perception↗
PubMed1984

Lack of effect of weak low frequency electromagnetic fields on chick embryogenesis.

Fertilised chicken eggs were incubated for 48 hours while exposed to pulsed trains of square wave magnetic fields having a duration of 0.5 msec and pulse repetition rates of 100 or 1000 Hz at magnetic field flux densities of 1.2 and 12 mu T. After exposure the embryos were scored blind for eight different gross structural features: primary vesicles, anterior neuropore, optic vesicles, auditory pits, truncal nervous system, heart, somites and blood vessels. There were no differences between exposed, sham-exposed and control eggs.

Animals↗
PubMed1984

Interaction between electromagnetic fields and cells: microelectrophoretic effect on ligands and surface receptors.

The aggregation between lectins and lymphocyte surface receptors can be affected strongly by a low-level electric field induced in the cell suspension by a time-varying magnetic field. One of the possible mechanisms is the microelectrophoretic effect due to the electric field, which influences the distance (in the mean square sense) between charged ligands and receptors when they are about to separate. On a purely theoretical basis, it is shown that, at low frequencies, an externally induced periodic electric field always decreases the mean lifetime of ligand-receptor complexes. As a consequence, the mitogenic gain obtained by lectin addition to cell suspension is decreased. These results suggest that such a mechanism, if effective, reduces the lectin mitogenic capability and offers a way of handling similar phenomena which have been described for other biological systems.

Electromagnetic Fields↗
PubMed1998

A simple experiment to study electromagnetic field effects: protection induced by short-term exposures to 60 Hz magnetic fields.

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 prior to being placed into anoxia. Survival was 39.6% (control), and 68.7% (field-exposed). As a positive control, embryos were heated prior to anoxia (57.6% survival). We conclude that: 1) 60 Hz magnetic field exposures reduce anoxia-induced mortality in chick embryos, comparable to reductions observed following heat stress, and 2) this is a simple and rapid experiment to demonstrate the existence of weak EM field effects.

Animals↗
PubMed1975

Electromagnetic field effects in nerve tissue.

In the present work, an attempt has been made to produce structural alterations in tissue from the nervous system of bullfrogs by means of a high-intensity electric field. The electric field used to expose the tissue was compased of a train of high-intensity, short-duration pulses. Theses pulses provide a high electric-field intensity in the tissue, yet a low enough absorbed-energy density to cause negligible thermal heating. Exposed and control tissue prepared for light microscope investigation was stained with thionin and hematoxylin and eosin stains. No gross histological alterations of the large motor neurons of the exposed tissue were found when compared with the control tissue.

Animals↗
PubMed1985

Auditory response in rats exposed to 2,450 MHz electromagnetic fields in a circularly polarized waveguide.

Rats were exposed to 2,450-MHz pulsed microwave fields in a circularly polarized waveguide. The threshold incident energy density per pulse was about 1.5 to 3 microJ/cm2 over the range 1-10 microseconds. The corresponding whole-body averaged specific absorption of energy was 0.9 to 1.8 mJ/kg per pulse. The same response was evoked when the incident energy density or absorbed energy density per pulse was the same, regardless of the pulse widths.

Animals↗
PubMed1989

Exposure to electromagnetic fields in arc welding.

Electric and magnetic fields at the power line frequency (60 Hz) and its harmonics have been measured around 22 arc welders. The electric field strengths in most cases were very low (1 V m-1) and only for one device reached 300 V m-1. Magnetic flux densities ranged from a few microT to a few hundred microT (a few A m-1 to a few hundred of A m-1). Several devices surveyed produced high magnetic flux densities (200-400 microT), which are rarely encountered in the environment and are representative of high occupational exposures.

Electromagnetic Fields↗
PubMed1983

Reduced mitogenic stimulation of human lymphocytes by extremely low frequency electromagnetic fields.

Blastogenesis of human peripheral blood lymphocytes stimulated in vitro by non-specific mitogens (PHA, ConA, PWM) upon exposure to extremely low frequency EMF has been studied. Different frequencies of square waveforms have been used. PHA-stimulation resulted in strong inhibitions as measured by [3H]thymidine incorporation. A frequency window (3-50 Hz) within which ConA-induced blastogenesis was significantly inhibited has been individuated. The mitogenic effect of PWM was significantly affected only at 3 Hz.

Adult↗