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PubMed2003

Effects of different intensities of extremely low frequency pulsed electromagnetic fields on formation of osteoclast-like cells.

Over the past 30 years, the beneficial therapeutic effects of selected low energy, time varying electromagnetic fields (EMF) have been documented with increasing frequency to treat therapeutically resistant problems of the musculoskeletal system. However, the underlying mechanisms at a cellular level are still not completely understood. In this study, the effects of extremely low frequency pulsed electromagnetic fields (ELF-PEMF) on osteoclastogenesis, cultured from murine bone marrow cells and stimulated by 1,25(OH)(2)D(3), were examined. Primary bone marrow cells were cultured from mature Wistar rats and exposed to ELF-PEMF stimulation daily for 7 days with different intensities of induced electric field (4.8, 8.7, and 12.2 micro V/cm rms) and stimulation times (0.5, 2, and 8 h/day). Recruitment and authentication of osteoclast-like cells were evaluated, respectively, by determining multinuclear, tartrate resistant acid phosphatase (TRAP) positive cells on day 8 of culture and by the pit formation assay. During the experiments, cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin 1-beta (IL-1beta), and prostaglandin-E(2) (PGE(2)) were assayed using the enzyme linked immunosorbent assay (ELISA). These findings suggest that ELF-PEMF can both enhance (approximately 50%) and suppress (approximately 27%) the formation of osteoclast-like cells in bone marrow culture, depending on the induced electric field intensity. In addition, consistent correlations were observed between TNF-alpha, IL-1beta, and osteoclast-like cell number after exposure to different induced electric field intensities of ELF-PEMF. This in vitro study could be considered as groundwork for in vivo ELF-PEMF clinical applications on some osteoclast-associated bone diseases.

Animals↗
PubMed2005

Developmental effects of electromagnetic fields.

This paper reviews experimental studies on the effects of radiofrequency (RF), extremely low frequency (ELF), and intermediate frequency (IF) electromagnetic fields on animal development. Numerous studies have shown that RF fields are teratogenic at exposure levels sufficiently high to cause significant increase of temperature. There is no consistent evidence of RF field effects at nonthermal exposure levels. Only a few studies have evaluated possible effects on postnatal development using sensitive endpoints, such as behavioral effects. ELF electric fields up to 150 kV/m have been evaluated in several mammalian species. The results are rather consistent and do not suggest adverse developmental effects. The results of studies on ELF magnetic fields suggest effects on bird embryo development, but not consistently in all studies. Results from experiments with other non-mammalian experimental models have also suggested subtle effects on developmental stability. In mammals, most studies have shown no effects of prenatal exposure to ELF or IF magnetic on gross external, visceral, or skeletal malformations. The only finding that shows some consistency is increase of minor skeleton alterations in several experiments. Taken as a whole, the results do not show robust adverse effects of ELF and IF fields on development. However, additional studies on the suggested subtle effects on developmental stability might increase our understanding of the sensitivity of biological organisms to weak low-frequency magnetic fields.

Aging↗
PubMed2007

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

Adult↗
PubMed2007

Extremely low frequency weak magnetic fields enhance resistance of NN tobacco plants to tobacco mosaic virus and elicit stress-related biochemical activities.

Increasing evidence has accumulated concerning the biological effects of extremely low frequency magnetic fields (ELF-MFs) in different plant models. In the present study, effects of ELF-MFs in tobacco plants reacting to tobacco mosaic virus (TMV) with a hypersensitive response (HR) were evaluated. Plants were exposed for 8 or 24 h (either before or after TMV inoculation) to a static MF, at either -17 or 13 microT, combined with a 10 Hz sinusoidal MF with different intensities (25.6 or 28.9 microT). The working variables were the area and number of hypersensitive lesions in leaves. Following ELF-MFs exposure, an increased resistance was detected, particularly after an 8-h treatment, as shown by the decrease in lesion area and number. Moreover, two enzyme activities involved in resistance mechanisms were analyzed: ornithine decarboxylase (ODC) and phenylalanine ammonia-lyase (PAL). Uninoculated leaves previously exposed to ELF-MFs in general showed a significant increase relative to controls in ODC and PAL activities, in particular for 13 microT static MF plus 28.9 microT, 10 Hz sinusoidal MF (24 h) treatment. In conclusion, ELF-MFs seem to influence the HR of tobacco to TMV, as shown by the increased resistance and changes in ODC and PAL activities, indicating the reliability of the present plant model in the study of bioelectromagnetic interactions.

Electromagnetic Fields↗
PubMed1993

Effects of 60 Hz electric and magnetic fields on the development of the rat cerebellum.

The effects of extremely low frequency (ELF) electromagnetic (EM) fields on the maturation of the rat cerebellum were studied. Newborn rats were exposed to 60 Hz electric and magnetic fields under three different combinations in a specially constructed apparatus. The pups were irradiated for 7-8 h daily, with a 30-min interruption for nursing. Pups were kept with their mothers for the remainder of the time. After approximately 1, 2, or 3 weeks of exposure, the pups were killed. Control pups were sham exposed. The somatic growth of the irradiated rats did not show any significant difference from sham-exposed controls. At 1 kV/m and 10 gauss exposure, there was a small but statistically significant decrease in cerebellar mass. In rats exposed at 1 kV/m and 10 gauss, DNA and RNA levels were significantly higher than those in sham-exposed controls at 6 and 13 days of age, but at 20 days, these two biochemical constituents were similar in both groups of rats. The ELF-EM treatment had no effect on protein and cerebroside concentrations. In terms of age effects, DNA and RNA exhibited increases from 6 to 13 days of age, and declined from 13 to 20 days. Protein and cerebroside levels exhibited increases during the 6-20-day periods. In rats exposed at 100 kV/m and 1 gauss, the DNA levels were initially less than those of sham-exposed controls at 8 days of age, reached approximately the same levels at 14 days, and then were higher than those of controls at 22 days. There was, therefore, a significant ELF-EM effect as well as a significant interaction between age and ELF-EM exposure. In terms of age effects, DNA levels for both control and exposed animals increased from 8 to 14 days. From 14 to 22 days, DNA levels of exposed rats continued to increase while those of the controls decreased. This age effect was significant. RNA levels in both groups of animals showed increases from 8 to 14 days of age, but the increase was less for the irradiated animals than for the controls. From days 14 to 22, RNA levels for both groups showed a reduction, but the decrease was greater in the irradiated than in control rats. ELF-EM treatment significantly reduced protein levels at 8 days of age, but at 14 to 22 days, protein levels of exposed rats were higher than those of controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2002

Magnetic fields produced by hand held hair dryers, stereo headsets, home sewing machines, and electric clocks.

A recent epidemiologic study reported associations between leukemia risk in children and their personal use of television (TV) sets, hair dryers, and stereo headsets, and the prenatal use by their mothers of sewing machines. To provide exposure data to aid in the interpretation of these findings, extremely and very low frequency (ELF and VLF) magnetic fields produced by a sample of each type of appliance were characterized in a field study of volunteers conducted in Washington DC and its Maryland suburbs. Questionnaire data regarding children's or mothers' patterns of usage of each type of appliance were also collected. ELF magnetic fields measured 10 cm from the nozzles of hair dryers were elevated over the ambient by a mean factor of 17 when these devices were in use. Fields near headsets being used to listen to music were not distinguishable from ambient levels except at frequencies below and well above 60 Hz and, even then, field levels were < 0.01 microT. Home sewing machines produced ELF magnetic fields that were elevated by a factor of 2.8 over ambient levels at the front surfaces of the lower abdomens of mothers. Estimated mean daily times of usage of hair dryers, stereo headsets, and sewing machines were 2.6, 19, and 17 minutes, respectively. These data and previously published data on TV sets, do not provide a consistent picture of increased (or decreased) leukemia risk in relation to increasing peak or time weighted average (TWA) ELF magnetic field exposure. The data could, however, conceivably be compatible with some more complex biophysical model with unknown properties. Overall, the results of this study provide little evidence supporting the hypothesis that peak or TWA ELF magnetic fields produced by appliances are causally related to the risk of childhood leukemia in children.

Adolescent↗
PubMed2003

The influences of extremely low frequency magnetic fields on drug-induced convulsion in mouse.

This study investigated the effects of extremely low frequency magnetic fields (ELF-MFs) on the sensitivity of seizure response to bicuculline, picrotoxin and NMDA in mice. The mice were exposed to either a sham or 20 G ELF-MFs for 24 hours. Convulsants were then administered i.p. at various doses. The seizure induction time and duration were measured and lethal dose (LD50) and convulsant dose (CD50) of the clonic and tonic convulsion were calculated. The analysis of glutamate, glycine, taurine and GABA of mouse brain was accomplished by HPLC. The mice exposed to ELF-MFs showed moderately higher CD50, LD50 and onset time on the bicuculline-induced seizure. However, the ELF-MFs did not influence them in the NMDA and picrotoxin-induced seizures. After the exposure to MFs exposure, the glutamate level was increased and GABA was decreased significantly in NMDA and picrotoxin-induced seizure. The level of glutamate and GABA were not changed by MFs in bicuculline-induced seizure. These results suggest that ELF-MFs may alter the convulsion susceptibility through GABAergic mechanism with the involvement of the level of glutamate and GABA.

Animals↗
PubMed2004

Plasma and lung concentrations of ceftazidime administered in continuous infusion to critically ill patients with severe nosocomial pneumonia.

OBJECTIVE: To determine the steady-state plasma and epithelial lining fluid (ELF) concentrations of ceftazidime administered in continuous infusion to critically ill patients with severe nosocomial pneumonia. DESIGN: Prospective, open-label study. SETTING: An intensive care unit and research ward in a university hospital. PATIENTS: A total of 15 adult patients with severe nosocomial bacterial pneumonia on mechanical ventilation were enrolled. INTERVENTIONS: All subjects received a 30 min intravenous infusion of 2 g ceftazidime followed by a continuous infusion of 4 g over 24 h. The concentrations of ceftazidime in plasma and ELF were determined at steady-state after 2 days of therapy by high performance liquid chromatography. MEASUREMENTS AND MAIN RESULTS: The mean +/-SD steady-state plasma and ELF concentrations of 4 g ceftazidime in continuous infusion were 39.6+/-15.2 microg/mL and 8.2+/-4.8 microg/mL, respectively, showing a mean +/-SD percentage penetration of ceftazidime into ELF of 20.6+/-8.9%. CONCLUSION: The administration of 4 g ceftazidime in continuous infusion in critically ill patients with severe nosocomial pneumonia provides concentrations in excess of the minimal inhibitory concentration of many susceptible organisms over the course of therapy both in serum and ELF. However, for some pathogens such as P. aeruginosa, higher doses of ceftazidime should be administered, or another agent should be used in combination.

Anti-Bacterial Agents↗
PubMed2006

Pharmacokinetics and lung concentrations of ertapenem in patients with ventilator-associated pneumonia.

OBJECTIVE: We conducted a prospective, open-label study to determine the steady-state serum and epithelial lining fluid (ELF) concentrations of unbound ertapenem administered once daily to critically ill patients with early-onset ventilator-associated pneumonia (VAP). DESIGN AND SETTING: Prospective, open-label study in an intensive care unit and research ward in a university hospital. PATIENTS: Fifteen patients with VAP received 1-h intravenous infusions of 1 g ertapenem once daily. INTERVENTIONS: After 2 days of therapy the steady-state serum and ELF concentrations of free ertapenem were determined by high-performance liquid chromatography. MEASUREMENTS AND RESULTS: The median (interquartile range) free ertapenem peak (C(max)), intermediate (C(12)), and trough (C(min)) concentrations (mg/l) 1, 12, and 24 h after the end of infusion were 30.3 (27.1-37.8), 4.8 (3.9-6.4), and 0.8 (0.5-1.2) in serum and 9.4 (8.0-10.7), 2.0 (1.1-2.5), and 0.3 (0.2-0.4) in ELF, respectively, showing a median free ertapenem percentage penetration in ELF of approx. 30%. The median (interquartile range) serum area under concentration-time curve of free ertapenem during the observational period was 226.7 mg h(-1) l(-1) (202.2-263.9). CONCLUSION: Our study shows satisfactory results, with unbound ertapenem concentrations both in serum and ELF exceeding the MIC(90) values of most of the causative pathogens encountered in early-onset VAP during 50-100% time. This suggests that 1 g intravenous ertapenem administered once daily should be effective during the treatment of early-onset VAP in critically ill patients with no known risk factors for multidrug-resistant pathogens.

Aged↗
PubMed2003

Intermittent extremely low frequency electromagnetic fields cause DNA damage in a dose-dependent way.

OBJECTIVES: Epidemiological studies have reported an association between exposure to extremely low frequency electromagnetic fields (ELF-EMFs) and increased risk of cancerous diseases, albeit without dose-effect relationships. The validity of such findings can be corroborated only by demonstration of dose-dependent DNA-damaging effects of ELF-EMFs in cells of human origin in vitro. METHODS: Cultured human diploid fibroblasts were exposed to intermittent ELF electromagnetic fields. DNA damage was determined by alkaline and neutral comet assay. RESULTS: ELF-EMF exposure (50 Hz, sinusoidal, 1-24 h, 20-1,000 mu T, 5 min on/10 min off) induced dose-dependent and time-dependent DNA single-strand and double-strand breaks. Effects occurred at a magnetic flux density as low as 35 mu T, being well below proposed International Commission of Non-Ionising Radiation Protection (ICNIRP) guidelines. After termination of exposure the induced comet tail factors returned to normal within 9 h. CONCLUSION: The induced DNA damage is not based on thermal effects and arouses concern about environmental threshold limit values for ELF exposure.

Adult↗
PubMed2006

Luteal-phase inhibin A and follicular-phase inhibin B levels are not characteristic of patients with an elevated LH-to-FSH ratio.

PURPOSE: To test whether serum inhibin levels are related to differences in gonadotropin concentrations between patients with an elevated LH-to-FSH ratio (ELF patients) and controls. METHODS: 32 ELF patients were matched with controls by age, body mass index (BMI), and cycle length. RESULTS: No statistically significant difference was found in follicular-phase inhibin B levels or midluteal inhibin A levels between cases and controls. Significant negative correlation was observed between follicular-phase inhibin B concentrations and BMI in ELF patients but not among controls. LH and FSH were positively related to inhibin B levels in ELF patients. Midluteal inhibin A correlated with sex hormone-binding globulin in controls but not in ELF patients. CONCLUSIONS: Neither follicular-phase inhibin B levels nor midluteal inhibin A levels are characteristic of patients with an elevated LH-to-FSH ratio. Opposite correlations with LH and BMI suggest dysregulation of inhibin secretion rather than dimeric inhibins having a central role to the endocrinological imbalance observed in polycystic ovary syndrome.

Adult↗
PubMed1989

Neuroendocrine mediated effects of electromagnetic-field exposure: possible role of the pineal gland.

Reports from recent epidemiological studies have suggested a possible association between extremely low frequency (ELF; including 50- or 60-Hz) electric- and magnetic-field exposure, and increased risk of certain cancers, depression, and miscarriage. ELF field-induced pineal gland dysfunction is a possible etiological factor in these effects. Work in our laboratory and elsewhere has shown that ELF electromagnetic-field exposure can alter the normal circadian rhythm of melatonin synthesis and release in the pineal gland. Consequences of reduced or inappropriately timed melatonin release on the endocrine, neuronal, and immune systems are discussed. Laboratory data linking ELF field exposure to changes in pineal circadian rhythms in both animals and humans are reviewed. The authors suggest that the pineal gland, in addition to being a convenient locus for measuring dyschronogenic effects of ELF field exposure, may play a central role in biological response to these fields via alterations in the melatonin signal.

Animals↗
PubMed1991

Transfer of NO2 through pulmonary epithelial lining fluid.

Absorption of inhaled NO2 across the pulmonary gas/tissue interface is principally governed by chemical reaction(s) rather than by physical solubility. While the kinetics of NO2 transfer into reactant-containing aqueous solutions appear to be bulk phase independent, it is unclear whether unreacted NO2 diffuses appreciably through the epithelial lining fluid (ELF) to cellular compartments. We avoided the difficulties associated with directly quantifying NO2 dissolved in biological fluids by indirectly determining the potential for NO2 penetration to underlying tissues. An in vitro system was developed which horizontally suspended a wettable, gas permeable, fibrous material between two gas chambers. Aqueous substrates were applied to the sieve material and NO2 (10.9 ppm) was introduced into one chamber and sampled for in the other. O2 served as a tracer gas. We determined the influence of ELF, a model biochemical (reduced glutathione; GSH), and PO4 buffer (control) on NO2 transfer as evaluated by "breakthrough time." (A) Both O2 and NO2 rapidly diffused through the sieve material when dry. Under PO4 wetted conditions, O2 continued to penetrate rapidly but NO2 transfer was slightly inhibited relative to O2. (B) Addition of GSH (1 mM) significantly prolonged NO2 breakthrough time. Increasing initial [GSH] resulted in concomitant prolongation of NO2 breakthrough time. (C) We observed a direct correlation between oxidation of sieve GSH and NO2 breakthrough. (D) Freshly harvested rat ELF inhibited NO2 transfer in a concentration-dependent manner similar to GSH. These data suggest that in the presence of reactant solutes, unreacted NO2 does not penetrate through the ELF layer. Reactive absorption must, therefore, occur primarily within the ELF compartment so that reaction products which induce subsequent toxicity are generated as a result of the initial uptake interactions.

Animals↗
PubMed2005

Intrapulmonary pharmacokinetics and pharmacodynamics of meropenem.

The objective of this study was to determine the plasma and intrapulmonary pharmacokinetic parameters of intravenously administered meropenem in healthy volunteers. Four doses of 0.5 g, 1.0 g or 2.0 g meropenem were administered intravenously to 20, 20 and 8 healthy adult subjects, respectively. Standardised bronchoscopy and timed bronchoalveolar lavage (BAL) were performed following administration of the last dose. Blood was obtained for drug assay prior to drug administration and at the time of BAL. Meropenem was measured in plasma, BAL fluid and alveolar cells (ACs) using a combined high pressure liquid chromatographic-mass spectrometric technique. Plasma, epithelial lining fluid (ELF) and AC pharmacokinetics were derived using non-compartmental methods. Cmax/MIC90 (where Cmax is the maximum plasma concentration and MIC90 is the minimum inhibitory concentration required to inhibit 90% of the pathogen), AUC/MIC90 (where AUC is the area under the curve for the mean concentration-time data), intrapulmonary drug exposure ratios and percent time above MIC90 during the dosing interval (%T > MIC90) were calculated for common respiratory pathogens with MIC90 values of 0.12-4 microg/mL. In the 0.5 g dose group, the Cmax (mean+/-S.D.), AUC(0-8 h) and half-life for plasma were, respectively, 25.8+/-5.8 microg/mL, 28.57 microg h/mL and 0.77 h; for ELF the values were 5.3+/-2.5 microg/mL, 12.27 microg h/mL and 1.51 h; and for ACs the values were 1.0+/-0.5 microg/mL, 4.30 microg h/mL and 2.61 h. In the 1.0 g dose group, the Cmax, AUC(0-8 h) and half-life for plasma were, respectively, 53.5+/-19.7 microg/mL, 55.49 microg h/mL and 1.31 h; for ELF the values were 7.7+/-3.1 microg/mL, 15.34 microg h/mL and 0.95 h; and for ACs the values were 5.0+/-3.4 microg/mL, 14.07 microg h/mL and 2.17 h. In the 2.0 g dose group, the Cmax, AUC(0-8 h) and half-life for plasma were, respectively 131.7+/-18.2 microg/mL, 156.7 microg h/mL and 0.89 h. The time above MIC in plasma ranged between 28% and 78% for the 0.5 g dose and between 45% and 100% for the 1.0 g and 2.0 g doses. In ELF, the time above MIC ranged from 18% to 100% for the 0.5 g dose and from 25% to 88% for the 1.0 g dose. In ACs, the time above MIC ranged from 0% to 100% for the 0.5 g dose and from 24% to 100% for the 1.0 g dose. Time above MIC in ELF and ACs for the 2.0 g dose was not calculated because of sample degradation. The prolonged T > MIC90 and high intrapulmonary drug concentrations following every 8 h administration of 0.5-2.0 g doses of meropenem are favourable for the treatment of common respiratory pathogens.

Adult↗
PubMed2006

Intrapulmonary pharmacokinetics and pharmacodynamics of high-dose levofloxacin in healthy volunteer subjects.

The objective of this study was to determine the plasma and intrapulmonary pharmacokinetic parameters of intravenously administered levofloxacin in healthy volunteers. Three doses of either 750 mg or 1000 mg levofloxacin were administered intravenously to 4 healthy adult subjects (750 mg) to 20 healthy adult subjects divided into five groups of 4 subjects (1000 mg). Standardised bronchoscopy and timed bronchoalveolar lavage (BAL) were performed following administration of the last dose. Blood was obtained for drug assay prior to drug administration and at the time of BAL. Levofloxacin was measured in plasma, BAL fluid and alveolar cells (ACs) using a sensitive and specific combined high-performance liquid chromatographic tandem mass spectrometric technique (HPLC/MS/MS). Plasma, epithelial lining fluid (ELF) and AC pharmacokinetics were derived using non-compartmental methods. The maximum plasma drug concentration to minimum inhibitory concentration ratio (C(max)/MIC(90)) and the area under the drug concentration curve to minimum inhibitory concentration ratio (AUC/MIC(90)) during the dosing interval were calculated for potential respiratory pathogens with MIC(90) values from 0.03 microg/mL to 2 microg/mL. In the 1000 mg dose group, the C(max) (mean+/-standard deviation (S.D.)), AUC(0-8h) and half-life were: for plasma, 9.2+/-1.9 microg/mL, 103.6 microg h/mL and 7.45 h; for ELF, 25.8+/-7.9 microg/mL, 279.1 microg h/mL and 8.10h; and for ACs, 51.8+/-26.2 microg/mL, 507.5 microg h/mL and 14.32 h. In the 750 mg dose group, the C(max) values in plasma, ELF and ACs were 5.7+/-0.4, 28.0+/-23.6 and 34.2+/-18.7 microg/mL, respectively. Levofloxacin concentrations were significantly higher in ELF and ACs than in plasma at all time points. For pathogens commonly associated with community-acquired pneumonia, C(max)/MIC(90) ratios in ELF ranged from 12.9 for Mycoplasma pneumoniae to 859 for Haemophilus influenzae, and AUC/MIC(90) ratios ranged from 139 to 9303, respectively. The C(max)/MIC(90) ratios in ACs ranged from 25.9 for M. pneumoniae to 1727 for H. influenzae, and AUC/MIC(90) ratios ranged from 254 to 16917, respectively. The C(max)/MIC(90) and AUC/MIC(90) ratios provide a pharmacokinetic rationale for once-daily administration of a 1000 mg dose of levofloxacin and are favourable for the treatment of community-acquired respiratory pathogens.

Adult↗
PubMed2005

Cell type-specific genotoxic effects of intermittent extremely low-frequency electromagnetic fields.

The issue of adverse health effects of extremely low-frequency electromagnetic fields (ELF-EMFs) is highly controversial. Contradictory results regarding the genotoxic potential of ELF-EMF have been reported in the literature. To test whether this controversy might reflect differences between the cellular targets examined we exposed cultured cells derived from different tissues to an intermittent ELF-EMF (50 Hz sinusoidal, 1 mT) for 1-24h. The alkaline and neutral comet assays were used to assess ELF-EMF-induced DNA strand breaks. We could identify three responder (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells), which points to the significance of the cell system used when investigating genotoxic effects of ELF-EMF.

Animals↗
PubMed2004

Magnetic field exposure saves rat cerebellar granule neurons from apoptosis in vitro.

Accumulating evidence demonstrates that extremely low frequency magnetic fields (ELF-MFs) are capable of modifying neuronal function. Here we examine the effect of ELF-MF exposure on neuronal apoptosis. For this purpose cerebellar granule neurons (CGNs) from postnatal rats were employed, which are known to undergo apoptosis under normal condition (5.4 mM K+) in vitro. Exposure to a rotating (50 Hz) ELF-MF for 5 days saved immature CGNs from apoptosis and promoted survival at the flux density of 300 mT, whereas virtually no neuronal survival was observed without exposure (sham). The survival-promoting effect of ELF-MFs occurred in a manner that depended on the size of culture flasks, suggesting that induced current plays a role in this phenomenon. A maximal survival-promoting effect was comparable to that of membrane depolarization (25 mM K+) and greater than that of brain-derived neurotrophic factor (BDNF). These results imply that ELF-MFs may serve as a potential tool for manipulating neuronal death and/or survival.

Animals↗
PubMed2004

Analysis of insulin like growth factor 1 and insulin like growth factor binding protein 3 levels in bronchoalveolar lavage fluid and serum of patients with lung cancer.

OBJECTIVE: Insulin like growth factor 1 (IGF-1) is recognized as a potent mitogen for many cancer cell lines and there is good evidence that lung cancer cells produce both IGF-1 and insulin like growth factor binding protein 3 (IGFBP-3). The aim of this study was to investigate the clinical significance of IGF-1 and IGFBP-3 levels in serum and in bronchoalveolar lavage (BAL) fluid by comparing lung cancer patients with healthy controls. METHODS: BAL fluid and serum samples were obtained from 24 lung cancer patients and 12 healthy controls, and were analyzed for IGF-1 and IGFBP-3 levels by a two site immunoradiometric assay. The recovered BAL fluid was standardized by albumin to remove the variable of dilution and the data was expressed in epithelial lining fluid (ELF). RESULTS: Serum IGF-1 and IGFBP-3 levels were lower in lung cancer patients, but the difference between the groups did not reach a statistical significance. IGF-1/IGFBP-3 ratio in ELF was significantly lower in lung cancer patients (P=0.035). Mean IGF-1 level in ELF was determined to be significantly lower in patients with distant metastasis (P=0.04). Serum IGF-1/IGFBP-3 ratio was found to be significantly lower in patients with distant (P=0.04) and nodal metastasis (P=0.03). Tumor stage was negatively correlated with IGF-1 level in ELF (P=0.05, r=-0.4) and serum IGF-1/IGFBP-3 ratio (P=0.04, r=-0.4). CONCLUSION: IGF-1 and IGFBP-3 levels both in serum and ELF might serve a clinical significance in patients with lung cancer. However, further studies comprising more cases are needed to investigate the clinical significance of IGF-1 and IGFBP-3 in lung cancer.

Aged↗