[Intermittent electromagnetic fields and their effect on awareness and headache].
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Adult↗
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[Electromagnetic fields and ventricular demand pacemakers].
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Electromagnetic Fields↗
The heat shock-induced cell cycle arrest is attenuated by weak electromagnetic fields.
Stress-induced effects in human acute leukaemia cells (HL-60) were studied by flow cytometry using the fluorescent dye carboxyfluorescein succinimidyl ester which allows the analysis of several successive cell generations for up to 10 days. Asynchronously cycling cells subjected to heat shock (30 min at 41 degrees C) responded in two distinct ways: while one fraction of the cell population (about 15%) re-entered the cell cycle after a short delay, other cells became arrested at different phases of the cell cycle and remained arrested for up to several days and finally underwent apoptosis. Weak electromagnetic fields (60 micro T, 50 Hz) alleviated the heat-induced block and the fraction of arrested cells was significantly smaller.
Cell Cycle↗
Electromagnetic fields used clinically to improve bone healing also impact lymphocyte proliferation in vitro.
An important aspect of medical device development is the need to understand how a device produces a specific biological effect. The focus can then be on optimizing that effect by device modification and repeated testing. Several reports from this lab have targeted programmed cell death, or apoptosis, as a cellular pathway that is induced by exposure of transformed leukemic T-cells in culture to specific frequency and intensity electromagnetic fields (EMFs). An EMF delivery device capable of selectively inducing T-cell apoptosis in human tissues could be used to enhance healing by limiting the production of molecules that promote inflammatory disorders such as psoriasis and tendonitis. In the present study, we examined the normal T-cell response to EMF exposure in vitro. In the peripheral blood, 70-80% of the lymphocytes are T-cells, and thus is a rich source of normal cells that match the transformed T-cells used in other experiments (Jurkat cells). We isolated lymphocytes from the peripheral blood of humans and rats, cultured them in nutritive medium and exposed them to either a complex 1.8 mT pulsed EMF (Electrobiology, Inc.), a 0.1 mT, 60 Hz power frequency EMF or a 0.2 mT, 100 Hz sinusoidal EMF. Control lymphocytes were cultured similarly, without field exposure. Lymphocytes were then treated with T-cell mitogens and evaluated for proliferative capacity after an additional 72 hours culture. Results indicate that T-cell proliferation is modulated by in vitro exposure to defined EMFs. The potential use of an EMF delivery device capable of selectively inducing such T-cell effects is discussed.
Animals↗
Reversal of cognitive impairment in an elderly parkinsonian patient by transcranial application of picotesla electromagnetic fields.
A 74 year old retired building inspector with a 15 year history of Parkinson's disease (PD) presented with severe resting tremor in the right hand, generalized bradykinesia, difficulties with the initiation of gait with freezing, mental depression and generalized cognitive impairment despite being fully medicated. Testing of constructional abilities employing various drawing tasks demonstrated drawing impairment compatible with severe left hemispheric dysfunction. After receiving two successive transcranial applications, each of 20 minutes duration, with AC pulsed electromagnetic fields (EMFs) of 7.5 picotesla flux density and frequencies of 5Hz and 7Hz respectively, his tremor remitted and there was dramatic improvement in his drawing performance. Additional striking improvements in his drawing performance occurred over the following two days after he continued to receive daily treatments with EMFs. The patient's drawings were subjected to a Reliability Test in which 10 raters reported 100% correct assessment of pre- and post drawings with all possible comparisons (mean 2 = 5.0; p < .05). This case demonstrates in PD rapid reversal of drawing impairment related to left hemispheric dysfunction by brief transcranial applications of AC pulsed picotesla flux density EMFs and suggests that cognitive deficits associated with Parkinsonism, which usually are progressive and unaffected by dopamine replacement therapy, may be partly reversed by administration of these EMFs. Treatment with picotesla EMFs reflects a "cutting edge" approach to the management of cognitive impairment in Parkinsonism.
Aged↗
The relationship between electromagnetic field and light exposures to melatonin and breast cancer risk: a review of the relevant literature.
Worldwide, breast cancer is the most common malignancy accounting for 20-32% of all female cancers. This review summarizes the peer-reviewed, published data pertinent to the hypothesis that increased breast cancer in industrialized countries is related to the increased use of electricity [Stevens, R.G., S. Davis 1996]. That hypothesis specifically proposes that increased exposure to light at night and electromagnetic fields (EMF) reduce melatonin production. Because some studies have shown that melatonin suppresses mammary tumorigenesis in rats and blocks estrogen-induced proliferation of human breast cancer cells in vitro, it is reasoned that decreased melatonin production leads to increased risk of breast cancer. To evaluate this hypothesis, the paper reviews epidemiological data on associations between electricity and breast cancer, and assesses the data on the effects of EMF exposure on melatonin physiology in both laboratory animals and humans. In addition, the results on the effects of melatonin on in vivo carcinogenesis in animals are detailed along with the controlled in vitro studies on melatonin's effects on human breast cancer cell lines. The literature is evaluated for strength of evidence, inter-relationships between various lines of evidence, and gaps in our knowledge. Based on the published data, it is currently unclear if EMF and electric light exposure are significant risk factors for breast cancer, but further study appears warranted. Given the ubiquitous nature of EMF and artificial light exposure along with the high incidence of breast cancer, even a small risk would have a substantial public health impact.
Animals↗
Treatment with AC pulsed electromagnetic fields normalizes the latency of the visual evoked response in a multiple sclerosis patient with optic atrophy.
Visual evoked response (VER) studies have been utilized as supportive information for the diagnosis of multiple sclerosis (MS) and may be useful in objectively monitoring the effects of various therapeutic modalities. Delayed latency of the VER, which reflects slowed impulse transmission in the optic pathways, is the most characteristic abnormality associated with the disease. Brief transcranial applications of AC pulsed electromagnetic fields (EMFs) in the picotesla flux density are efficacious in the symptomatic treatment of MS and may also reestablish impulse transmission in the optic pathways. A 36 year old man developed an attack of right sided optic neuritis at the age of 30. On presentation he had blurring of vision with reduced acuity on the right and fundoscopic examination revealed pallor of the optic disc. A checkerboard pattern reversal VER showed a delayed latency to right eye stimulation (P100 = 132 ms; normal range: 95-115 ms). After he received two successive applications of AC pulsed EMFs of 7.5 picotesla flux density each of 20 minutes duration administered transcranially, there was a dramatic improvement in vision and the VER latency reverted to normal (P100= 107 ms). The rapid improvement in vision coupled with the normalization of the VER latency despite the presence of optic atrophy, which reflects chronic demyelination of the optic nerve, cannot be explained on the basis of partial or full reformation of myelin. It is proposed that in MS synaptic neurotransmitter deficiency is associated with the visual impairment and delayed VER latency following optic neuritis and that the recovery of the VER latency by treatment with pulsed EMFs is related to enhancement of synaptic neurotransmitter functions in the retina and central optic pathways. Recovery of the VER latency in MS patients may have important implications with respect to the treatment of visual impairment and prevention of visual loss. Specifically, repeated pulsed applications of EMFs may maintain impulse transmission in the optic nerve and thus potentially sustain its viability.
Adult↗
Reversal of visuospatial hemi-inattention in patients with chronic progressive multiple sclerosis by treatment with weak electromagnetic fields.
The occurrence of cognitive impairment including visuoperceptive and visuospatial deficits have long been recognized to occur in patients with multiple sclerosis (MS) particularly among patients with a chronic progressive course. In MS visuospatial and visuoperceptive deficits have been attributed to the presence of diffuse demyelinating plaques which "disconnect" the brainstem reticular formation and other subcortical structures involved in attention and arousal from cortical areas thus causing a state of hypoarousal. It has been reported recently that brief external applications of alternating pulsed electromagnetic fields (EMFs) in the picotesla (pT) range intensity improved visuoperceptive and visuospatial functions in MS patients. The present communication concerns three female patients with chronic progressive course of MS (mean age: 52.3 +/- 2.0 yrs; mean duration of illness: 17.6 +/- 10.2 yrs) who, on tests of free drawings, demonstrated visuospatial hemi-inattention as a feature of more global cognitive deterioration. In all patients brief applications of EMFs rapidly reversed this cognitive deficit. These findings support prior observations demonstrating that pT EMFs may bring about reversal of certain cognitive deficits in MS patients which, to my knowledge, remain unaffected by any other treatment modality.
Attention↗
Treatment with electromagnetic fields reverses the long-term clinical course of a patient with chronic progressive multiple sclerosis.
It is estimated that 10-20% of patients with multiple sclerosis (MS) have a chronic progressive (CP) course characterized by an insidious onset of neurological deficits followed by steady progression of disability in the absence of symptomatic remission. To date no therapeutic modality has proven effective in reversing the clinical course of CP MS although there are indications that prolonged treatment with picotesla electromagnetic fields (EMFs) alters the clinical course of patients with CP MS. A 40 year-old woman presented in December of 1992 with CP MS with symptoms of spastic paraplegia, loss of trunk control, marked weakness of the upper limbs with loss of fine and gross motor hand functions, severe fatigue, cognitive deficits, mental depression, and autonomic dysfunction with neurogenic bladder and bowel incontinence. Her symptoms began at the age of 18 with weakness of the right leg and fatigue with long distance walking and over the ensuing years she experienced steady deterioration of functions. In 1985 she became wheelchair dependent and it was anticipated that within 1-2 years she would become functionally quadriplegic. In December of 1992 she began experimental treatment with EMFs. While receiving regularly weekly transcortical treatments with AC pulsed EMFs in the picotesla range intensity she experienced during the first year improvement in mental functions, return of strength in the upper extremities, and recovery of trunk control. During the second year she experienced the return of more hip functions and recovery of motor functions began in her legs. For the first time in years she can now initiate dorsiflexion of her ankles and actively extend her knees voluntarily. Over the past year she started to show signs of redevelopment of reciprocal gait. Presently, with enough function restored in her legs, she is learning to walk with a walker and is able to stand unassisted and maintain her balance for a few minutes. She also regained about 80% of functions in the upper limbs and hands. Most remarkably, there was no further progression of the disease during the 4 years course of magnetic therapy. This patient's clinical recovery cannot be explained on the basis of a spontaneous remission. It is suggested that pulsed applications of picotesla EMFs affect the neurobiological and immunological mechanisms underlying the pathogenesis of CP MS.
Adult↗
Influence of pulsing electromagnetic field on the frequency of sister-chromatid exchanges in cultured mammalian cells.
Exposures of Chinese hamster cells to pulsing electromagnetic field (PEMF) with 0.18-2.5 mT did not influence the baseline frequency of sister-chromatid exchanges (SCE). The results suggest that PEMF with the magnetic intensity examined does not interfere with DNA replication nor produce DNA lesions, thereby leading to an increased frequency of SCE.
Animals↗
[Modifying effect of light and electromagnetic field on development of mammary tumors induced by N-nitrosomethyl urea in female rats].
Female rats aged I month and older were kept indoors in darkness, under lighting for 24 hours or exposed to ordinary lighting (light--12 hrs; darkness--12 hrs). Three weeks after the beginning of the experiment, they received N-nitrosomethyl urea (NMU) treatment in the dose of 50 mg/kg, intravenously, at weekly intervals, and were exposed to alternating 50 Hz (AMF) or static 0.2 oersted, (DMF) electromagnetic field radiation for 3 hrs, daily. Under usual lighting conditions, NMU treatment was followed by the development of mammary gland adenocarcinoma (MGA) in 31% of the animals. However, AMF or DMF treatment was followed by a shorter period of latency, without affecting MGA frequency. Constant lighting was found to stimulate a sharp increase in carcinogenesis: MGA frequency in groups receiving NMU, NMU+AMF or NMU+DMF was 57, 81 and 61%, respectively; latency period dropped by half as compared with usual lighting conditions. Conversely, the rats constantly kept in darkness revealed significant inhibition of mammary gland carcinogenesis, MGA frequency in NMU, NMU+AMF or NMU+DMF groups being 3, 4 and 2%, respectively. A blood serum--hormone assay showed constant lighting to decrease melatonin level and to increase prolactin concentration for all the modalities of carcinogenic treatment used. The results point to a significant promoting effect of constant lighting on mammary gland carcinogenesis by NMU in rats. This effect is potentiated by additional AMF or DMF treatment. Conversely, constant darkness inhibits mammary gland carcinogenesis and mitigates the pernicious effect of low-frequency electro-magnetic radiation.
Animals↗
Blood-brain barrier and electromagnetic fields: effects of scopolamine methylbromide on working memory after whole-body exposure to 2.45 GHz microwaves in rats.
We first verified that our 12-arm radial maze test enabled demonstration of memory deficits in rats treated with the muscarinic antagonist scopolamine hydrobromide (0.5mg/kg, i.p.). We then investigated whether a systemically-injected quaternary-ammonium derivate of this antagonist (scopolamine methylbromide; MBR), which poorly crosses the blood-brain barrier (BBB), altered maze performance after a 45-min exposure to 2.45 GHz electromagnetic field (EMF; 2 micros pulse width, 500 pps, whole-body specific energy absorption rate [SAR] of 2.0 W/kg, +/-2dB and brain averaged SAR of 3.0 W/kg, +/-3 dB); if observed, such an alteration would reflect changes in BBB permeability. The drug was injected before or after exposure. Controls were naive rats (no experience of the exposure device) and sham-exposed rats (experience of the exposure device without microwaves). In a final approach, rats were subjected to i.v. injections of Evans blue, a dye binding serum albumin, before or after EMF exposure. Whether scopolamine MBR was injected before or after exposure, the exposed rats did not perform differently from their naive or sham-exposed counterparts. Thus, EMFs most probably failed to disrupt the BBB. This conclusion was further supported by the absence of Evans blue extravasation into the brain parenchyma of our exposed rats.
Albumins↗
Influence of high-frequency electromagnetic fields on different modes of cell death and gene expression.
PURPOSE: International thresholds for exposure to non-ionizing radiation leading to non-thermal effects were conservatively set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The aim of this study was to examine whether biological effects such as different modes of cell death and gene expression modifications related to tumorgenesis are detectable above the threshold defined. MATERIALS AND METHODS: Human leukaemia cells (HL-60) grown in vitro were exposed to electromagnetic fields (EMF; t 1/2(r) about 1 ns; field strength about 25 times higher than the ICNIRP reference levels for occupational exposure) leading to non-thermal effects using a high-voltage-improved GTEM cell 5302 (EMCO) connected to a pulse generator NP20 (C = 1 nF, U(Load) = 20kV). HL-60 cells were harvested at 0, 24, 48 and 72 h after radiation exposure. Micronuclei, apoptosis and abnormal cells (e.g. necrosis) were determined using morphological criteria. In parallel, the expression of 1176 genes was measured using Atlas Human 1.2. Array. Based on high data reproducibility calculated from two independent experiments (> 99%), array analysis was performed. RESULTS: No significant change in apoptosis, micronucleation, abnormal cells and differential gene expression was found. CONCLUSIONS: Exposure of HL-60 cells to EMFs 25 times higher than the ICNIRP reference levels for occupational exposure failed to induce any changes in apoptosis, micronucleation, abnormal morphologies and gene expression. Further experiments using EMFs above the conservatively defined reference level set by the ICNIRP may be desirable.
Apoptosis↗
[Effect of the light regime and electromagnetic fields on mammary carcinogenesis in female rats].
Outbred female rats from the age of 1 month were kept at rooms with 12 h light: 12 h dark (LD), 24 h light (LL) and 24 h dark (DD) regimens and 2 weeks later were exposed to 3 weekly i.v. injections of NMU at the dose of 50 mg/kg and starting in 2 days after first NMU administration-to variable or static magnetic fields (VMF and SMF). Exposure to LL regimen significantly promoted whereas the exposure to DD regimen significantly inhibited NMU-induced mammary carcinogenesis. RIA of serum samples from rats maintained under different light regimens has shown that exposure to LL followed by decrease of melatonin level and increase of prolactin level at all of modifying factors (NMU, VMF, SMF). Surgical light deprivation inhibits NMU-indiced mammary carcinogenesis in female rats. The primary role of pineal function in the modifying effects of light/dark regimens and electromagnetic fields on mammary carcinogenesis are suggested.
Adenocarcinoma↗
The acute effects of exposure to the electromagnetic field emitted by mobile phones on human attention.
The aim of our study was to investigate the effects of acute mobile phone exposure on a range of tasks which tapped capacity and processing speed within the attentional system. Thirty-eight healthy volunteers were randomly assigned to either an experimental group which was exposed to a connected mobile phone or a control group in which the mobile phone was switched off. Subjects remained blind to mobile phone status throughout duration of study. The experimental group were exposed to an electromagnetic field emitted by a 900 MHz mobile phone for 30 min. Cognitive performance was assessed at three points (prior to mobile phone exposure, at 15 and 30 min post-exposure) using six cognitive neuropsychological tests (digit span and spatial span forwards and backwards, serial subtraction and verbal fluency). Significant differences between the two groups were evident after 5 min on two tests of attentional capacity (digit span forwards and spatial span backwards) and one of processing speed (serial subtraction). In all three instances, performance was facilitated following mobile phone exposure. No deficits were evident. These findings are discussed in terms of possible functional and neuroanatomical bases.
Adult↗
Test of a trust and confidence model in the applied context of electromagnetic field (EMF) risks.
Trust is an important factor in risk management. There is little agreement among researchers, however, on how trust in risk management should be studied. Based on a comprehensive review of the trust literature a "dual-mode model of social trust and confidence" is proposed. Trust and confidence are separate but, under some circumstances, interacting sources of cooperation. Trust is based on value similarity, and confidence is based on performance. According to our model, judging similarity between an observer's currently active values and the values attributed to others determines social trust. Thus, the basis for trust is a judgment that the person to be trusted would act as the trusting person would. Interpretation of the other's performance influences confidence. Both social trust and confidence have an impact on people's willingness to cooperate (e.g., accept electromagnetic fields or EMF in the neighborhood). The postulated model was tested in the applied context of EMF risks. Structural equation modeling procedures and data from a random sample of 1,313 Swiss citizens between 18 and 74 years old were used. Results indicated that after minor modifications the model explained the data very well. In the applied context of EMF risks, both trust and confidence had an impact on cooperation. Results suggest that the dual-mode model of social trust and confidence could be used as a common framework in the field of trust and risk management. Practical implications of the results are discussed.
Adolescent↗
Treatment of scaphoid nonunion with casting and pulsed electromagnetic fields: a study continuation.
This article presents a continuation of a study of the treatment of scaphoid nonunion with pulsed electromagnetic fields (PEMF) and cast immobilization. Fifty-four patients were reviewed. The overall success rate for healing has decreased since the previous review from 80% to 69%. Proximal pole fractures healed in 50%. Success in nonunions with associated radiographic evidence of avascular necrosis decreased from 89% to 73%. Although we believe that the indications for use of PEMF have not changed significantly, this study suggests that a successful outcome with PEMF and casting is less likely than previously reported. We believe that until additional clinical studies have further defined the indications, treatment protocol, and efficacy of this method PEMF treatment should be a secondary alternative to bone-grafting procedures.
Adolescent↗
Weak electromagnetic fields attenuate tremor in multiple sclerosis.
It has been estimated that about 75% of patients diagnosed with multiple sclerosis (MS) have tremor which can be exceedingly disabling. The most common tremor observed in patients with MS is a cerebellar intention tremor ('kinetic tremor') although postural tremor ('static tremor') is also common and often extremely incapacitating. Currently there is no effective medical treatment for the tremor of MS which, in some severe cases, may be abolished by stereotactic thalamotomy. It was reported recently that extracranial application of brief AC pulsed electromagnetic fields (EMFs) in the picotesla (pT) range produced improvement in motor and cognitive functions in patients with MS. The present communication concerns three MS patients with a chronic progressive course of the disease (mean age: 39.3 +/- 8.3 years; mean duration of illness: 11.3 +/- 3.2 years) in whom brief external applications of pulsed EMFs of 7.5 pT intensity reduced intention and postural tremors resulting in significant functional improvement. The report suggests that these extremely low intensity EMFs are beneficial also in the treatment of tremors in MS and that this treatment may serve as an alternative method to stereotactic thalamotomy in the management of tremor in MS. The mechanisms by which EMFs attenuate the tremors of MS are complex and are thought to involve augmentation of GABA and serotonin (5-HT) neurotransmission in the cerebellum and its outflow tracts.
Adult↗