Time-varying magnetic fields increase cytosolic free Ca2+ in HL-60 cells

1990 ◽  
Vol 259 (4) ◽  
pp. C687-C692 ◽  
Author(s):  
J. J. Carson ◽  
F. S. Prato ◽  
D. J. Drost ◽  
L. D. Diesbourg ◽  
S. J. Dixon
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electromagnetic Fields ◽  
Biological Effects ◽  
Static Field ◽  
Free Calcium ◽  
Time Varying ◽  
Parallel Control ◽  
Magnetic Resonance Imaging Mri ◽  
Radiofrequency Electromagnetic Field

Electromagnetic fields have been reported to cause a variety of biological effects. It has been hypothesized that many of these phenomena are mediated by a primary effect on the concentration of cytosolic free calcium ([Ca2+]i). We investigated the effects of exposure to electromagnetic fields on [Ca2+]i in HL-60 cells using the Ca2(+)-sensitive fluorescent indicator indo-1. Indo-1-loaded cell samples were exposed to a radiofrequency electromagnetic field, a static magnetic field, and a time-varying magnetic field, which were generated by a magnetic resonance imaging (MRI) unit. We found that a 23-min exposure to all three fields, in combination, induced a significant increase in [Ca2+]i of 31 +/- 8 (SE) nM (P less than 0.01, n = 13) from a basal level of 121 +/- 8 nM. Also, cells exposed to only the time-varying magnetic field had a mean [Ca2+]i that was 34 +/- 10 nM (P less than 0.01, n = 11) higher than parallel control samples. Separate exposure to the radio-frequency (6.25 MHz) or static field (0.15 T) had no detectable effects. These results demonstrate that time-varying magnetic fields alter [Ca2+]i and suggest that at least some of the reported biological effects of time-varying magnetic fields may arise from elevation of [Ca2+]i.

Biological and Health Effects of Electromagnetic Fields Related to the Operation of MRI/TMS

SPIN ◽  
2017 ◽  
Vol 07 (04) ◽  
pp. 1740009 ◽  
Author(s):  
Tsukasa Shigemitsu ◽  
Shoogo Ueno
Keyword(s):  
Magnetic Field ◽  
Health Effects ◽  
Electromagnetic Fields ◽  
Biological Effects ◽  
Diagnostic Technique ◽  
Diagnostic Techniques ◽  
Safety Issues ◽  
Nonionizing Radiation ◽  
Magnetic Resonance Imaging Mri ◽  
Radiofrequency Electromagnetic Field

This paper reviews issues of biological effects and safety aspects of the electromagnetic fields related to both Magnetic Resonance Imaging (MRI) and Transcranial Magnetic Stimulation (TMS) as a diagnostic technique. The noninvasive character of these diagnostic techniques is based on the utilization of the electromagnetic fields such as the static magnetic field, time-varying magnetic field, and radiofrequency electromagnetic field. Following the short view of the history and the principle of these noninvasive techniques, we review the biological effects of the electromagnetic fields, the health effects and safety issues related to MRI/TMS environments. Through a discussion of biological and health effects, it shows briefly guidelines which provide a consideration in human risk for both patients and medical staff. Finally, safety issues related to MRI/TMS are discussed with the highlighting of the guideline such as the International Commission on NonIonizing Radiation Protection (ICNIRP) and EMF Directive (Directve2013/35/EU) of European Union.

scholarly journals EM Site A.C. Magnetic Field Sources, Surveys and Solutions Part IV: Survey Data Analysis

1996 ◽  
Vol 4 (4) ◽  
pp. 20-21
Author(s):  
Curt Dunnam
Keyword(s):  
Magnetic Field ◽  
Data Analysis ◽  
Magnetic Fields ◽  
Survey Data ◽  
Field Survey ◽  
Survey Methods ◽  
Time Varying ◽  
Measured Field ◽  
The Magnetic Field ◽  
Analyze Data

Up to the present waypoint in this series on EM site magnetic fields, we have identified typical sources of time-varying magnetic field intensities, examined salient field characteristics and illustrated correct survey methods. Our goal this month is to analyze data collected at a proposed site and answer the key question of whether or not the candidate site is, as far as magnetic fields go, acceptable for EM use. In the process of analyzing the magnetic field survey data we will define some of the interpretive techniques involved and observe the distinction between localized (a.c. power) and non-localized (geomagnetic) time-varying fields. Finally, we will discuss the implications of EM susceptibility threshold vs. measured field ratios when considering remedial site shielding.

Development of a Therapeutic Device for Osteoporosis

2013 ◽  
Vol 302 ◽  
pp. 603-606
Author(s):  
Tian Yue ◽  
Lei Tao
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Fields ◽  
Biological Effects ◽  
Homogeneous Magnetic Field ◽  
Pulsed Electromagnetic Fields ◽  
Treatment Of Osteoporosis ◽  
Non Invasive ◽  
Helmholtz Coils ◽  
Prevention And Treatment ◽  
Pulsed Electromagnetic

Pulsed electromagnetic fields (PEMF) have been reported as a non-invasive way in the prevention and treatment of osteoporosis. A new PEMF generator was designed to produce more homogeneous magnetic field than normal Helmholtz coils. The intensity and distribution of magnetic field y were calculated theoretically. The results showed that magnetic field generated by improved Helmholtz coils (three identical coils) is more intensive and homogeneous than normal Helmholtz coils (two identical coils). Moreover, this apparatus might play a significant role in the study of biological effects of PEMF on osteoporosis.

scholarly journals NMR Relaxivities of Paramagnetic Lanthanide-Containing Polyoxometalates

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7481
Author(s):  
Aiswarya Chalikunnath Venu ◽  
Rami Nasser Din ◽  
Thomas Rudszuck ◽  
Pierre Picchetti ◽  
Papri Chakraborty ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Contrast Agents ◽  
Current Trend ◽  
Image Contrast ◽  
Relaxation Rates ◽  
Wide Range ◽  
Magnetic Resonance Imaging Mri ◽  
Nmr Sensitivity ◽  
Applied Fields

The current trend for ultra-high-field magnetic resonance imaging (MRI) technologies opens up new routes in clinical diagnostic imaging as well as in material imaging applications. MRI selectivity is further improved by using contrast agents (CAs), which enhance the image contrast and improve specificity by the paramagnetic relaxation enhancement (PRE) mechanism. Generally, the efficacy of a CA at a given magnetic field is measured by its longitudinal and transverse relaxivities r1 and r2, i.e., the longitudinal and transverse relaxation rates T1−1 and T2−1 normalized to CA concentration. However, even though basic NMR sensitivity and resolution become better in stronger fields, r1 of classic CA generally decreases, which often causes a reduction of the image contrast. In this regard, there is a growing interest in the development of new contrast agents that would be suitable to work at higher magnetic fields. One of the strategies to increase imaging contrast at high magnetic field is to inspect other paramagnetic ions than the commonly used Gd(III)-based CAs. For lanthanides, the magnetic moment can be higher than that of the isotropic Gd(III) ion. In addition, the symmetry of electronic ground state influences the PRE properties of a compound apart from diverse correlation times. In this work, PRE of water 1H has been investigated over a wide range of magnetic fields for aqueous solutions of the lanthanide containing polyoxometalates [DyIII(H2O)4GeW11O39]5– (Dy-W11), [ErIII(H2O)3GeW11O39]5– (Er-W11) and [{ErIII(H2O)(CH3COO)(P2W17O61)}2]16− (Er2-W34) over a wide range of frequencies from 20 MHz to 1.4 GHz. Their relaxivities r1 and r2 increase with increasing applied fields. These results indicate that the three chosen POM systems are potential candidates for contrast agents, especially at high magnetic fields.

scholarly journals Trichomonas vaginalis and Giardia lamblia Growth Alterations by Low-Frequency Electromagnetic Fields

2019 ◽  
Author(s):  
Abraham Octavio RODRÍGUEZ-DE LA FUENTE ◽  
Ricardo GOMEZ-FLORES ◽  
José Antonio HEREDIA-ROJAS ◽  
Edna Marbella GARCÍA-MUÑOZ ◽  
Javier VARGAS-VILLARREAL ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electromagnetic Fields ◽  
Giardia Lamblia ◽  
Trichomonas Vaginalis ◽  
Low Frequency ◽  
Antagonistic Effect ◽  
Logarithmic Phase ◽  
Physical Factors ◽  
Field Exposure

Background: There is an increasing interest in using physical factors such as magnetic fields as antimicrobial strategy, with variable results. The current study was aimed to evaluate the influence of extremely low-frequency electromagnetic fields (ELF-EMFs) on the axenically-cultured parasite protozoans Trichomonas vaginalis and Giardia lamblia growth. Methods: Bioassays were developed using T. vaginalis, GT-13 and G. lamblia IMSS-0989 strains cultured at 37 ºC in TYI-S-33 medium. The following treatment regimens and controls were considered: (a) cells exposed to ELF-EMFs, (b) untreated cells, (c) cells treated with Metronidazole, used as positive controls, and (d) cells co-exposed to ELF-EMFs and Metronidazole. When cultures reached the end of logarithmic phase, they were exposed to ELF-EMFs for 72 h, in a standardized magnetic field exposure facility. For determining cytotoxic effects, trophozoite density was blindly evaluated in a Neubauer chamber. Results: A significant decrease in trophozoite growth was observed for T. vaginalis, in magnetic field-treated cultures. On the other hand, cultures co-exposed to ELF-EMFs and Metronidazole showed no significant differences when compared with cultures treated with Metronidazole alone. On the contrary, an increased trophozoite density was observed in G. lamblia cultures after exposure to magnetic fields. An absence of a synergistic or antagonistic effect was observed. Conclusion: ELF-EMFs induced T. vaginalis and G. lamblia growth alterations, indicating a potential effect in cell cycle progression.

scholarly journals Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs

2018 ◽  
Author(s):  
P. J. Hore
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Upper Bound ◽  
Prolonged Exposure ◽  
Radical Pair ◽  
Biological Effects ◽  
Radical Pair Mechanism ◽  
Childhood Leukaemia ◽  
Radical Pairs ◽  
Increased Risk

AbstractProlonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.

Analysis of Biological Effect of AC-DC Electromagnetic Fields using the Lorenz Model

2011 ◽  
pp. 31-53
Author(s):  
Malka N. Halgamuge ◽  
Chathurika D. Abeyrathne ◽  
Priyan Mendis
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electromagnetic Fields ◽  
Biological Effect ◽  
Initial Velocity ◽  
Charged Particles ◽  
Initial Position ◽  
Dc Magnetic Field ◽  
Ac Electric Field

Electromagnetic fields (EMF) are essential to various applications directly involving humans. Fears about the biological effect of exposure to electromagnetic fields drive enormous research into this area. This research generates conflicting results, and consequently, uncertainty regarding possible health effects. This chapter studies a nonlinear Lorenz model describing interactions among charged particles and combined alternating (AC: alternating current) and static (DC: direct current) electromagnetic fields, for various combinations of frequencies, field strengths and relative angle (?) between the AC and DC magnetic fields. We investigate the effect on charged particles of three possible combinations of alternating and static electromagnetic fields: (i) AC electric field and DC magnetic field (ii) AC magnetic field and DC magnetic field (iii) AC electric field and AC and DC magnetic field. Then the behavior of the particle in these fields with different initial conditions and strong directional effects is observed when the angle between AC and DC magnetic fields is varied. The results show that the cyclotron resonance frequency is affected by charged particles’ initial position and initial velocity. Further, we observe strong effects of electric and magnetic fields on a charged particle in a biological cell with initial position and initial velocity.

scholarly journals On the Nature of Magnetars

2004 ◽  
Vol 218 ◽  
pp. 265-266
Author(s):  
Ya. N. Istomin
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Electromagnetic Fields ◽  
Gamma Ray ◽  
X Ray ◽  
Surface Magnetic Field ◽  
The Core ◽  
Neutron Star Crust ◽  
High Magnitude

The electromagnetic fields of magnetodipole radiation can penetrate to the conducting matter of a neutron star crust and create there electric currents and tangential magnetic fields of high magnitude. The solution obtained here has the form of surface magnetic field discontinuities propagating through the crust to the core. This model explains the phenomena of magnetars — Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars.

Impact of Electromagnetic Radiation on the Human Organism

2016 ◽  
Vol 695 ◽  
pp. 295-302
Author(s):  
Liliana Sachelarie ◽  
Mihaela Păpușa Vasiliu ◽  
Dorina Maria Farcas ◽  
Oana Maria Daraba ◽  
Laura Romila
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Fields ◽  
Magnetic Stimulation ◽  
Clinical Medicine ◽  
Heart Diseases ◽  
Biological Effects ◽  
Healing Process ◽  
Human Organism ◽  
Brain Functions

Interaction mechanisms and biological effects that different types of radiation could exert upon humans have been studied by many authors. Different studies investigated the reactions of various types of electrical equipment, power lines, mobile phones and other upon humans, their influence on the brain functions, public health or if magnetic fields (MFs) can be used for pain relief. Some authors found out that electromagnetic fields (EMFs) might be a factor which determined a number of chronic illnesses (cancer, heart diseases and sleep disorders) even to low intensity. But on the other side, because the EMFs are part of nature, being radiated by human body and its organs, the quality and intensity of the energy can either support or destroy health. Magnetic fields and electromagnetic fields are useful modalities to treat various pathologies and diseases. A number of clinical studies, in vivo animal experiments and in vitro cellular and membrane researches, suggested that EMFs and MFs stimulation reduce pain and accelerate the healing process. However, EMFs are still not widely used in clinical medicine. It is accepted that pain control occurs via a series of integrated stages, each with particular objectives essential to the tissue/system repairing processes. Electric and magnetic stimulation have been proven to provide beneficial and reproducible healing effects even when other methods have failed. As for the MFs, this is an excellent possibility as a non – invasive method to control and treat pain. Magnetic stimulation of a patient is different from drug treatment. As technology proliferates and people use more and more electronic devices, some researchers suspect EMFs contribute to a subtle assault upon people’s immune system and health. This paper aims to review the way that electromagnetic fields and other types of radiations interaction at molecular level with human organism.

Sign in / Sign up

Export Citation Format

Share Document