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PubMed2005

Nitric oxide level in the nasal and sinus mucosa after exposure to electromagnetic field.

OBJECTIVE: The purpose of this study was to examine the changes in nitric oxide (NO) level in the nasal and paranasal sinus mucosa after exposure radiofrequency electromagnetic fields (EMF). STUDY DESIGN AND SETTING: Thirty male Sprague-Dawley rats were randomly grouped as follows: EMF group (group I; n, 10), EMF group in which melatonin received (group II; n, 10) and the control (sham operated) group (group III; n, 10). Groups I and II were exposed to a 900 MHz. Oral melatonin was given in group II. Control rats (group III) were also placed in the tube as the exposure groups, but without exposure to EMF. At the end of 2 weeks, the rats were sacrificed, and the nasal and paranasal sinus mucosa dissected. NO was measured in nasal and paranasal mucosa. RESULTS: The nasal and paranasal sinus mucosa NO levels of group I were significantly higher than those of the control group (group III) ( P < 0.05). However, there was no statistically significant difference between group II and the control group (group III) regarding NO output ( P > 0.05). CONCLUSION: Exposure to EMF released by mobile phones (900 MHz) increase NO levels in the sinus and nasal mucosa. SIGNIFICANCE: Increased NO levels may act as a defense mechanism and presumably related to tissue damage. In addition, melatonin may have beneficial effect to prevent these changes in the mucosa.

Animals↗
PubMed2005

Pulsed electromagnetic fields reduce knee osteoarthritic lesion progression in the aged Dunkin Hartley guinea pig.

An experimental in vivo study was performed to test if the effect of Pulsed Electromagnetic Fields (PEMFs) on chondrocyte metabolism and adenosine A2a agonist activity could have a chondroprotective effect on the knee of Dunkin Hartley guinea-pigs of 12 months with spontaneously developed osteoarthritis (OA). After a pilot study, 10 animals were randomly divided into two groups: PEMF-treated group (6 h/day for 3 months) and Sham-treated group. Microradiography and histomorphometry were performed on the entire articular surface of knee joints used in evaluating chondropathy severity, cartilage thickness (CT), cartilage surface Fibrillation Index (FI), subchondral bone plate thickness (SBT) and histomorphometric characteristics of trabecular epiphyseal bone. The PEMF-treated animals showed a significant reduction of chondropathy progression in all knee examined areas (p<0.05). CT was significantly higher (p<0.001) in the medial tibia plateaus of the PEMF-treated group when compared to the Sham-treated group. The highest value of FI was observed in the medial tibia plateau of the Sham-treated group (p<0.05). Significant lower values were observed in SBT of PEMF-treated group in comparison to Sham-treated group in all knee examined areas (p<0.05). The present study results show that PEMFs preserve the morphology of articular cartilage and slower the progression of OA lesions in the knee of aged osteoarthritic guinea pigs. The chondroprotective effect of PEMFs was demonstrated not only in the medial tibial plateau but also on the entire articular surface of the knee.

Aging↗
PubMed2005

Assessment of potential effects of the electromagnetic fields of mobile phones on hearing.

BACKGROUND: Mobile phones have become indispensable as communication tools; however, to date there is only a limited knowledge about interaction between electromagnetic fields (EMF) emitted by mobile phones and auditory function. The aim of the study was to assess potential changes in hearing function as a consequence of exposure to low-intensity EMF's produced by mobile phones at frequencies of 900 and 1800 MHz. METHODS: The within-subject study was performed on thirty volunteers (age 18-30 years) with normal hearing to assess possible acute effect of EMF. Participants attended two sessions: genuine and sham exposure of EMF. Hearing threshold levels (HTL) on pure tone audiometry (PTA) and transient evoked otoacoustic emissions (TEOAE's) were recorded before and immediately after 10 min of genuine and/or sham exposure of mobile phone EMF. The administration of genuine or sham exposure was double blind and counterbalanced in order. RESULTS: Statistical analysis revealed no significant differences in the mean HTLs of PTA and mean shifts of TEOAE's before and after genuine and/or sham mobile phone EMF 10 min exposure. The data collected showed that average TEOAE levels (averaged across a frequency range) changed less than 2.5 dB between pre- and post-, genuine and sham exposure. The greatest individual change was 10 dB, with a decrease in level from pre- to post- real exposure. CONCLUSION: It could be concluded that a 10-min close exposure of EMFs emitted from a mobile phone had no immediate after-effect on measurements of HTL of PTA and TEOAEs in young human subjects and no measurable hearing deterioration was detected in our study.

Adolescent↗
PubMed2004

Effects of 2.45-GHz electromagnetic fields with a wide range of SARs on micronucleus formation in CHO-K1 cells.

There has been considerable discussion about the influence of high-frequency electromagnetic fields (HFEMF) on the human body. In particular, HFEMF used for mobile phones may be of great concern for human health. In order to investigate the properties of HFEMF, we have examined the effects of 2.45-GHz EMF on micronucleus (MN) formation in Chinese hamster ovary (CHO)-K1 cells. MN formation is induced by chromosomal breakage or inhibition of spindles during cell division and leads to cell damage. We also examined the influence of heat on MN formation, since HFEMF exposure causes a rise in temperature. CHO-K1 cells were exposed to HFEMF for 2 h at average specific absorption rates (SARs) of 5, 10, 20, 50, 100, and 200 W/kg, and the effects on these cells were compared with those in sham-exposed control cells. The cells were also treated with bleomycin alone as a positive control or with combined treatment of HFEMF exposure and bleomycin. Heat treatment was performed at temperatures of 37, 38, 39, 40, 41, and 42 degrees C. The MN frequency in cells exposed to HFEMF at a SAR of lower than 50 W/kg did not differ from the sham-exposed controls, while those at SARs of 100 and 200 W/kg were significantly higher when compared with the sham-exposed controls. There was no apparent combined effect of HFEMF exposure and bleomycin treatment. On heat treatment at temperatures from 38-42 degrees C, the MN frequency increased in a temperature-dependent manner. We also showed that an increase in SAR causes a rise in temperature and this may be connected to the increase in MN formation generated by exposure to HFEMF.

Animals↗
PubMed2006

Exposure of mouse preosteoblasts to pulsed electromagnetic fields reduces the amount of mature, type I collagen in the extracellular matrix.

We tested the hypothesis that exposure of a mouse preosteoblast cell line to pulsed electromagnetic fields (PEMF) would affect components of the extracellular matrix. We report that exposure of MC3T3-E1 cells to a single PEMF waveform significantly reduced the amount of mature, alpha1(I) collagen in the extracellular matrix (ECM) and the conditioned medium, without affecting the amount of total ECM protein. This decrease was not due to changes in the steady-state level of Col1A1 mRNA or to degradation of mature collagen. We then tested the effect of three distinct PEMF waveforms, two orthogonal coil orientations, and two waveform amplitude levels on the amount of alpha1(I) collagen in the conditioned medium. A sequence of factorial ANOVAs and stepwise regression modeling revealed that the period (duration) of the individual pulses accounted for a significant proportion of the variance associated with the amount of alpha1(I) collagen in the conditioned medium. The total variance accounted for, however, was small (R(2)=0.155, p<0.001 and R(2)=0.172, p<0.001, in the horizontal and vertical orientations, respectively). The positive and negative regression coefficients for the coil orientations revealed that the influence of pulse period was significantly different for the orthogonal coil orientations (p<0.001). The findings imply that the dominant influence of PEMF on the amount of mature, alpha1(I) collagen in the ECM is related to variables other than those expressed in the time-amplitude domain. The results provide objective direction toward identifying waveform characteristics that contribute to the observed between-waveform differences with regard to collagen. Advances in this area may lead toward improving waveforms and waveform delivery protocols.

Animals↗
PubMed2005

Electromagnetic fields at mobile phone frequency induce apoptosis and inactivation of the multi-chaperone complex in human epidermoid cancer cells.

The exposure to non-thermal microwave electromagnetic field (MW-EMF) at 1.95 MHz, a frequency used in mobile communication, affects the refolding kinetics of eukaryotic proteins (Mancinelli et al., 2004). On these basis we have evaluated the in vivo effect of MW-EMF in human epidermoid cancer KB cells. We have found that MW-EMF induces time-dependent apoptosis (45% after 3 h) that is paralleled by an about 2.5-fold decrease of the expression of ras and Raf-1 and of the activity of ras and Erk-1/2. Although also the expression of Akt was reduced its activity was unchanged likely as a consequence of the increased expression of its upstream activator PI3K. In the same experimental conditions an about 2.5-fold increase of the ubiquitination of ras and Raf-1 was also found and the addition for 12 h of proteasome inhibitor lactacystin at 10 microM caused an accumulation of the ubiquitinated isoforms of ras and Raf-1 and counteracted the effects of MW-EMF on ras and Raf-1 expression suggesting an increased proteasome-dependent degradation induced by MW-EMF. The exposure of KB cells to MW-EMF induced a differential activation of stress-dependent pathway with an increase of JNK-1 activity and HSP70 and 27 expression and with a reduction of p38 kinase activity and HSP90 expression. The overexpression of HSP90 induced by transfection of KB cells with a plasmid encoding for the factor completely antagonized the apoptosis and the inactivation of the ras --> Erk-dependent survival signal induced by MW-EMF. Conversely, the inhibition of Erk activity induced by 12 h exposure to 10 mM Mek-1 inhibitor U0126 antagonized the effects induced by HSP90 transfection on apoptosis caused by MW-EMF. In conclusion, these results demonstrate for the first time that MW-EMF induces apoptosis through the inactivation of the ras --> Erk survival signaling due to enhanced degradation of ras and Raf-1 determined by decreased expression of HSP90 and the consequent increase of proteasome dependent degradation.

Apoptosis↗
PubMed1991

[Standardization of electromagnetic fields of 3-30 MHz with reference to the time factor].

In chronic experiments (4 months) in rabbits, rats, and mice biological effects were investigated from 7 exposure regimen of electromagnetic fields with a frequency of 24 MHz at field strengths of the electric field component of 125, 250, 500, and 1,000 V/m, respectively, and an exposure time of 0.25, 1, and 4 hrs. respectively. The effects on the CNS, the immune and hormone systems, the peripheral blood and on the spermato and embryo genesis were estimated. The results delivered the basis for the introduction of an index. In point of time different limit values are to be determined according to the energetic load. A concrete value for the energetic load 7,200 (V/m)2.h is proposed as maximum allowable field strength of the electric component 300 V/m.

Animals↗
PubMed2002

Electromagnetic field hazards involving adjustable shunt valves in hydrocephalus.

OBJECT: Standard therapy for hydrocephalus involves shunts and valves, which are frequently adjustable. Because of increasing "electromagnetic smog" (for example, that generated by cellular phones), these valves are often exposed to electromagnetic fields. METHODS: Various magnetic fields were tested for their effects on two different kinds of adjustable valves. The minimum magnetic flux density affecting the adjustment of the valve was determined. Results were compared with magnetic fields found in contemporary everyday life. In homogeneous magnetic fields the adjustment of one valve (Sophysa model SM8) was changed at 5 mT, whereas the second valve (Codman Hakim model CM) was not affected. In nonhomogeneous fields the SM8 valve was affected at 25 mT and the CM valve at 15 mT. Thus, these valves may be affected by headphones and telephone receivers. Surroundings such as the Japanese magnetic suspension railway and the lead cabin of electrical railway engines, in which critical levels of magnetic flux may be present, may also affect adjustable valves. The high-frequency fields of cellular phones, however, have no effect on these valves. CONCLUSIONS: Every surgeon who implants these valves and every patient who receives them should know the possible hazards. The valve selection should be adapted to the environment of the patient. Devices with critical levels of electromagnetic flux that are used in the homes of patients should be replaced by ones with lower magnetic fields. The future construction of these valves should be modified in such a way that their adjustment requires a higher magnetic flux density, so that the valves become less sensitive to unwanted effects from environmental magnetic fields.

Cerebrospinal Fluid Shunts↗
PubMed2004

Differences in lethality between cancer cells and human lymphocytes caused by LF-electromagnetic fields.

The lethal response of cultured cancer cells lines K-562, U-937, DG-75, and HL-60 were measured directly after a 4 h exposure to a pulsating electromagnetic field (PEMF, sinusoidal wave form, 35 mT peak, 50 Hz) [Traitcheva et al. (2003): Bioelectromagnetics 24:148-158] and 24 h later, to determine the post-exposure effect. The results were found to depend on the medium, pH value, conductivity, and temperature. From these experiments, suitable conditions were chosen to compare the vitality between K-562 cells and normal human lymphocytes after PEMF treatment and photodynamic action. Both agents enhance necrosis synergistically for diseased as well as for healthy cells, but the lymphocytes are more resistant. The efficacy of PEMF on the destruction of cancer cells is further increased by heating (hyperthermia) of the suspension up to 44 degrees C or by lowering the pH-value (hyperacidity) to pH 6.4. Similar apoptosis and necrosis can be obtained using moderate magnetic fields (B < or = 15 mT 50/60 Hz), but this requires longer treatment of at least over a week. PEMF application combined with anticancer drugs and photodynamic therapy will be very effective.

Aged↗
PubMed2000

[Cellular radio systems. Problems faced in assessing exposure to electromagnetic fields].

Over twenty years of its existence, cellular radio systems have become one of the major sources of human exposure to electromagnetic field (EMF) of high frequency. With the increasing number of cellular phones, the interest in health effects of exposure to EMF emitted by them continues to grow. At present, there is a general opinion that thermal effect (change of electromagnetic energy into thermal energy) is an essential mechanism of possible biological effects. The majority of world standards for exposure to EMF are based on this effect. The author presents Polish standards and those of the International Commission on Nonionizing Radiation Protection (ICNIRP) for EMF of frequencies used in cellular radio systems, both basic that limits SAR (Specific Absorption Rate), and derived that limits the power density, as well as intensity of electric and magnetic fields. Attention was also turned to the problems concerning the application of cellular phones and those resulting from the character of the field emitted by them to which their users are exposed. Bearing in mind the results of the laboratory analyses of SAR values occurring in the user's head, and measurements of power density in the vicinity of the base station antennas, it can be stated that, in view of binding and recommended standards, cellular phones do not present any hazard to their users (private or professional). However, it should be stressed that standards adopted protect the user's head against the thermal effect, whereas the question on whether they also protect against non-thermal effects still remains without answer.

Electromagnetic Fields↗
PubMedDate not supplied

Outcomes after posterolateral lumbar fusion with instrumentation in patients treated with adjunctive pulsed electromagnetic field stimulation.

Fusion success and clinical outcome were determined in 48 high-risk patients who underwent posterolateral lumbar fusions with internal fixation and were treated with adjunctive pulsed electromagnetic field (PEMF) stimulation postoperatively. An independent radiographic assessment demonstrated a success rate of 97.9%. Following treatment, 59% of the working patients returned to their employment. Overall clinical assessment was excellent in 4.2% of patients, good in 79.2%, and fair in 16.7%; no patient had a poor clinical assessment.

Activities of Daily Living↗
PubMed1984

Use of pulsed electromagnetic fields in Perthes disease: report of a pilot study.

A pilot study of pulsed electromagnetic fields (PEMFs) in the treatment of 10 older children with unilateral Perthes disease of the hip is reported. Patients were allowed to walk using crutches, with the affected hip splinted by the Birmingham containment orthosis during the day. For 10 h during the night the affected hip was exposed to PEMFs delivered via a pair of coils, mounted anterior and posterior to the hip joint on a plastic abduction orthosis. Splintage time of this group was compared with that of 72 patients selected at random from a historical control group of 200 patients. The 72 patients and the 10 children were assigned to early or late groups depending on the radiologic evolution of the disease when treatment commenced. The group of 10 children showed an overall reduction of time in all splintage of 32% in early cases (to 12.8 months) and 18% in late cases (to 13.5 months). No untoward effects were detected during the 2 years that these children have been under observation. In view of the apparent safety of PEMFs and their effects in this limited population of older patients with advanced Perthes disease, a double-blind study in younger patients with earlier lesions seems to be justified.

Child↗
PubMed2003

Electromagnetic fields, polychlorinated biphenyls, and prostate cancer mortality in electric utility workers.

The purpose of this study was to determine whether there was an association between occupational exposure to electromagnetic fields (EMFs) or polychlorinated biphenyls (PCBs) and mortality from prostate cancer among US electric utility workers. Data on participants, who were current and former employees of five large US electric utility companies, had been collected during 1987-1994, and the mortality of the cohort was followed through 1988. This nested case-control study contained 387 cases, men whose underlying cause of death was prostate cancer, and five controls for each case. Workers categorized in the highest 10 percent of EMF exposure were twice as likely to die from prostate cancer as those exposed to EMFs at lower levels, after adjustment for PCB exposure, race, and active work status within the past 2 years (odds ratio = 2.02, 95% confidence interval (CI): 1.34, 3.04). The odds ratio for PCB exposure and prostate cancer mortality was 1.47 (95% CI: 0.97, 2.24) after adjustment for suspected confounding factors. Exposure to high levels of both EMFs and PCBs showed no association with prostate cancer mortality. Non-White race was strongly associated with risk of prostate cancer mortality (odds ratio = 3.67, 95% CI: 2.66, 5.06). The association between EMF exposure and prostate cancer mortality warrants further investigation.

Adult↗
PubMed2006

Ultra high frequency-electromagnetic field irradiation during pregnancy leads to an increase in erythrocytes micronuclei incidence in rat offspring.

Mobile telephones and their base stations are an important ultra high frequency-electromagnetic field (UHF-EMF) source and their utilization is increasing all over the world. Epidemiological studies suggested that low energy UHF-EMF emitted from a cellular telephone may cause biological effects, such as DNA damage and changes on oxidative metabolism. An in vivo mammalian cytogenetic test, the micronucleus (MN) assay, was used to investigate the occurrence of chromosomal damage in erythrocytes from rat offspring exposed to a non-thermal UHF-EMF from a cellular phone during their embryogenesis; the irradiated group showed a significant increase in MN occurrence. In order to investigate if UHF-EMF could also alter oxidative parameters in the peripheral blood and in the liver - an important hematopoietic tissue in rat embryos and newborns - we also measured the activity of antioxidant enzymes, quantified total sulfhydryl content, protein carbonyl groups, thiobarbituric acid-reactive species and total non-enzymatic antioxidant defense. No significant differences were found in any oxidative parameter of offspring blood and liver. The average number of pups in each litter has also not been significantly altered. Our results suggest that, under our experimental conditions, UHF-EMF is able to induce a genotoxic response in hematopoietic tissue during the embryogenesis through an unknown mechanism.

Acid Phosphatase↗
PubMed1999

Correlation between pulsed electromagnetic fields exposure time and cell proliferation increase in human osteosarcoma cell lines and human normal osteoblast cells in vitro.

We have exposed cultured bone cells to a pulsed electromagnetic field (PEMF) for different times to find the minimal exposure time necessary to stimulate an increase of DNA synthesis. We used two different human osteosarcoma cell lines, TE-85 and MG-63, and human normal osteoblast cell (NHOC) obtained from surgical bone specimens. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmoltz coils powered by a pulse generator (1.3-ms pulse, repeated at 75 Hz) for different periods of time. [3H]Thymidine incorporation was used to evaluate cell proliferation. The two osteosarcoma cell lines increase their thymidine incorporation when exposed to a PEMF for at least 30 min, both in a medium containing 10% fetal calf serum and in a serum-free medium. NHOC are known to increase their cell proliferation when exposed to PEMF but only if cultured in the presence of 10% fetal calf serum. In this experimental condition, three of the four cell lineages studied required at least 9 h of PEMF exposure to increase their DNA synthesis, whereas one cell lineage increased its cell proliferation after 6 h of PEMF exposure. Our observations confirm the hypothesis that the proliferative responses of NHOC and human osteosarcoma cell lines to PEMF exposure are quite different. Moreover, NHOC required minimal exposure times to PEMF to increase their cell proliferation, similar to that needed to stimulate bone formation in vivo.

Adult↗
PubMedDate not supplied

[The combined action of different forms of iodine and organic iodine compounds and of superhigh-frequency electromagnetic fields on the excitability and accommodative capacity of nervous and muscular tissues in frogs].

Experiments on 130 male lake frogs were made to study a combined action of SHF electromagnetic fields (microwaves) and baths KI + I2, DMSO, KI + I2 + DMSO, iodinol, iodinol + DMSO, humic acids, humic acids + KI + I2, humic acids + DMSO, sapropel + DMSO on excitability and accommodation ability of nervous and muscular tissues. The most perspective combinations (by the number of statistically significant shifts of 6 electrophysiological parameters) were selected for screening on warm-blooded animals. These were SHF microwaves + KI + I2, SHF microwaves + iodinol.

Animals↗
PubMed2003

Alteration of A(3) adenosine receptors in human neutrophils and low frequency electromagnetic fields.

The present study was designed to evaluate the binding and functional characterization of A(3) adenosine receptors in human neutrophils exposed to low frequency, low energy, pulsing electromagnetic fields (PEMFs). Great interest has grown concerning the use of PEMF in the clinical practice for therapeutic purposes strictly correlated with inflammatory conditions. Saturation experiments performed using the high affinity and selective A(3) adenosine antagonist 5N-(4-methoxyphenyl-carbamoyl)amino-8-propyl-2-(2-furyl)pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine ([3H]-MRE 3008F20) revealed a single class of binding sites with similar affinity in control and in PEMF treated human neutrophils (K(D)=2.36+/-0.16 and 2.45+/-0.15 nM, respectively). PEMFs treatment revealed that the receptor density was statistically increased (P<0.01) (B(max)=451+/-18 and 736+/-25fmolmg(-1) protein, respectively). Thermodynamic data indicated that [3H]-MRE 3008F20 binding in control and in PEMF-treated human neutrophils was entropy and enthalpy driven. Competition of radioligand binding by the high affinity A(3) receptor agonists, N(6)-(3-iodo-benzyl)-2-chloro-adenosine-5'-N-methyluronamide (Cl-IB-MECA) and N(6)-(3-iodo-benzyl)adenosine-5'-N-methyl-uronamide (IB-MECA), in the absence of PEMFs revealed high and low affinity values similar to those found in the presence of PEMFs. In both experimental conditions, the addition of GTP 100 microM shifted the competition binding curves of the agonists from a biphasic to a monophasic shape. In functional assays Cl-IB-MECA and IB-MECA were able to inhibit cyclic AMP accumulation and their potencies were statistically increased after exposure to PEMFs. These results indicate in human neutrophils treated with PEMFs the presence of significant alterations in the A(3) adenosine receptor density and functionality.

Binding, Competitive↗
PubMed2006

[Effect of 1.8 GHz radiofrequency electromagnetic fields on the expression of microtubule associated protein 2 in rat neurons].

OBJECTIVE: To investigate the changes of gene expression in rat neurons induced by 1.8 GHz radiofrequency electromagnetic fields (RF EMF) and to screen for the RF EMF-responsive genes. METHODS: Newly-born SD rats in 24 hours were sacrificed to obtain cortex and hippocampus neurons. The cells were divided randomly into two groups: the experiment group (the irradiation group) and the control group (the false irradiation group). In the irradiation group, after twelve days' culture, neurons were exposed to 1.8 GHz RF EMF modulated by 217 Hz at a specific absorption rate (SAR) of 2 W/kg for 24 hours (5 minutes on/10 minutes off) while in the false control group, the neurons were put in the same waveguide as in the irradiation group, but were not exposed to any irradiation. The total RNA was isolated and purified immediately after exposure. The affymetrix rat neurobiology U34 assay was used for detecting the changes in gene expression profile according to the manufacturer's instruction. RF EMF-responsive candidate gene was confirmed by using ribonuclease protection assay (RPA). RESULTS: Among 1200 candidate genes, the expression levels of 34 genes were up or down regulated. Microtubule associated protein 2 (Map2) gene was selected as the candidate and subjected to further analysis. RPA data clearly revealed that Map2 was statistically significantly up-regulated after neurons were exposed to the RF EMF (P < 0.05). CONCLUSION: The modulation of gene expression and function of Map2 as a neuron specific cytoskeleton protein is crucial to maintain the normal framework and function of neurons. The finding that 1.8 GHz RF EMF exposure increases the expression of Map2 might indicate some unknown effects of RF EMF on neurons.

Animals↗