Some recommendations for experimental work in magnetobiology, revisited (original) (raw)
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Magnetite in human tissues: A mechanism for the biological effects of weak ELF magnetic fields
Bioelectromagnetics, 1992
Due to the apparent lack of a biophysical mechanism, the question of whether weak, lowfrequency magnetic fields are able to influence living organisms has long been one of the most controversial subjects in any field of science. However, two developments during thc past decade have changed this perception dramatically, the first being the discovery that many organisms, including humans, biochemically precipitate the ferrimagnetic mineral magnetite (Fe,O,). In the magnetotactic bacteria, the geomagnetic response is based on either biogenic magnetite or greigite (Fe,S,). and reasonably good evidence exists that this is also the case in higher animals such as the honey bee. Second, the development of simple behavioral conditioning experiments for training honey bees to discriminate magnetic fields demonstrates conclusively that at least one terrestrial animal is capable of detecting earth-strength magnetic fields through a sensory process. In turn, the existence of this ability implies the presence of specialized receptors which interact at the cellular level with weak magnetic fields in a fashion exceeding thermal noise. A simple calculation shows that magnetosomes moving in response to earth-strength ELF fields are capable of opening trans-membrane ion channels, in a fashion sitnilar to those predicted by ionic resonance models. Hence, the presence of trace levels of biogenic magnetite in virtually all human tissues examined suggests that similar biophysical processes may explain a variety of weak field ELF bioeffects. o 1992 Wiley-LiPs, Inc.
Influence of the Magnetic Field on the Living Organisms and Humans
Ecological Engineering and Environment Protection, 2019
The question of the influence of magnetism on biological objects for years has been a debate with many contradictory opinions. The article provides a brief overview of publications and various and contradictory views on the influence of magnetic fields on living organisms and humans. An explanation is sought for findings made in various scientific studies, as well as an answer to the question: Can a permanent magnetic field be useful for our health and under what conditions? Key words: magnetic field, health, diagnostic, physiotherapy, physiological response
The Environmentalist, 2007
The present contribution points to the mechanisms of bioresponse caused by magnetic fields, paying attention to their action not only at the ionic, molecular or macromolecular levels but also at the levels of cells, tissues and organisms. The significance of findings concerning the magnetic-field dependence of cell proliferation, necrosis or apoptosis and cell volume or membrane fluidity is judged by comparing the results obtained in a solenoid, where a magnetic field can be added to the geomagnetic field, with those obtained in a magnetically shielded room, where the magnetic fields can be attenuated or null. This comparative criterion was particularly required when the differences found between the data provided by experimental samples and the data provided by control samples are small per se, as observed in estimating the magnetic-field dependence of expression of single genes or the magnetic-field dependence of total genome replication, transcription and translation. The report analyzes the magnetic-field dependence of the interactions between host animal cells and infecting bacteria and, in the framework of studies on the origin and adaptation of life on Earth, theoretical insights paving the way to elucidating the mechanisms of magnetic-field interactions with biosystems of different orders of organization are considered from the viewpoint of the “biological windows” thermodynamics. Thus, analogously to what is known for ionizing radiations, an inverse correlation emerged between the intensity of given magnetic fields and the biological complexity.
Effects and molecular mechanisms of the biological action of weak and extremely weak magnetic fields
Biophysics, 2010
A number of effects of weak combined (static and alternating) magnetic fields with an alternating component of tens and hundreds nT at a collinear static field of 42 μT, which is equivalent to the geomagnetic field, have been found: activation of fission and regeneration of planarians Dugesia tigrina, inhibition of the growth of the Ehrlich ascites carcinoma in mice, stimulation of the production of the tumor necrosis factor by macrophages, decrease in the protection of chromatin against the action of DNase 1, and enhancement of protein hydrolysis in systems in vivo and in vitro. The frequency and amplitude ranges for the alternating component of weak combined magnetic fields have been determined at which it affects various biological systems. Thus, the optimal amplitude at a frequency of 4.4 Hz is 100 nT (effective value); at a frequency of 16.5 Hz, the range of effective amplitudes is broader, 150–300 nT; and at a frequency of 1 (0.5) Hz, it is 300 nT. The sum of close frequencies (e.g., 16 and 17 Hz) produces a similar biological effect as the product of the modulating (0.5 Hz) and carrying frequencies (16.5 Hz), which is explained by the ratio A = A 0sinω1t + A 0sinω2t = 2A 0sin(ω1 + ω2)t/2cos(ω1–ω2)t/2. The efficiency of magnetic signals with pulsations (the sum of close frequencies) is more pronounced than that of sinusoidal frequencies. These data may indicate the presence of several receptors of weak magnetic fields in biological systems and, as a consequence, a higher efficiency of the effect at the simultaneous adjustment to these frequencies by the field. Even with consideration of these facts, the mechanism of the biological action of weak combined magnetic fields remains still poorly understood.
Analysis of Biological Effects and Limits of Exposure to Weak Magnetic Fields
Adverse biological outcomes due to thermal effects of exposure to high power magnetic fields are well understood and are the basis for standards for limiting human exposure to such fields. Over the past few decades a controversy has arisen over possible adverse biological effects due to exposure to weak, low frequency magnetic fields. This paper involves a critical analysis of the voluminous literature with a view to a theoretical investigation and comparison of the most prominent limits of exposure to weak magnetic fields and geomagnetic field to elucidate the main points of contention. Most of the weak magnetic fields that have been used in these experiments are below international exposure limits and quite a few fields are below Adair’s minimum theoretical exposure limit. There is a large variation in the response of biological systems for various AC magnetic field strength to frequency ratio with no clear correlation. These results demonstrate that characterizing the biological effects by AC magnetic field strength to frequency ratio does not appear to be a reliable technique.
Bio-effects of high magnetic fields: A study using a simple animal model
Magnetic Resonance Imaging, 1992
The desire to do clinical imaging and spectroscopy at magnetic field strengths greater than 2 Tesla (T) necessitates investigation of possible bioeffects at these high fields. A simple T-maze was utilized to evaluate the aversive effects of exposure to three levels of static magnetic field (0,1.5, and 4 T). The right arm of the maze extended into the center of a 30-cm horizontal bore magnet, while the left arm extended into a mock magnet bore with the same dimensions. The self-shielded design of the magnet reduces the fringe field to zero within 1 m of the bore, placing the start box of the maze outside the 5-G line of the magnet. Each rat performed a total of ten trials at each level of magnetic field strength. A follow-up subset was run at 4 T with the maze reversed. At 0 T, the rats entered the magnet freely. No significant differences from the control were observed at 1.5 T. At 4 T, however, in 97% of the trials the rats would not enter the magnet. In the maze-reversed subset a majority of the rats turned toward the magnet, indicating that they had learned an aversive response from the previous trials at 4 T. However, in only 4 decisions out of 58 did the rats actually enter the magnet. Eighteen decisions to turn around were made at the edge of the magnet in a region of strong field gradients (up to 13 T/m) and a field strength up to 1.75 T. We propose that the aversive response is most likely due to magnetic induction effects caused by motion in a strong magnetic field gradient.
Therapeutic use of moderate magnetostatic fields
2015
A big debate is still dividing the scientific community about detrimental or beneficial effects of Static Magnetic Fields (SMFs) exposure on living matter. The heterogeneous findings are depending on the different experimental set up used, i.e., magnetic induction from 10$ -7 $ to more than 10 T, homogenous or inhomogeneous field, time of exposure and on the biological samples, i.e., from in vitro cultured cells to living organisms. In spite of the amount of publications providing medical evidence for the beneficial effects of SMF exposure can exert on living matter, a researcher must kept his obligatory scepticism due to the difficulties comparing different measurements, to the commercial interests and to poor scientific rigor. Nevertheless, their use has gained wide community acceptance for pain relief but not for more serious diseases, such as cancer. In this mini-review we will discuss on the studies on the therapeutic use of moderate magnetic induction SMFs, focusing on those p...
Effects of static magnetic fields in biology: role of free radicals
Frontiers in Bioscience, 2008
Introduction 3. Weak-intensity SMF 3.1. Magnetic compass is based on "a radical pair mechanism" 3.2. Impact of geomagnetic activity on melatonin 3.3. Weak SMF effects on biochemical reactions 3.4. Summary of weak SMF effects on magnetic compass, melatonin release and biochemical reactions 4. Moderate-intensity SMF 4.1. Control of biochemical reactions with moderate SMF 4.2. Moderate SMF effects on ROS 4.3. Moderate SMF effects on RNS 4.4. Summary of moderate SMF effects on FRR 5. Strong-intensity SMF 5.1. Control of biochemical reactions with strong SMF 5.2. Strong SMF effects on ROS 5.3. Strong SMF effects on RNS 5.4. Summary of strong SMF effects on FRR 6. Perspectives 7. Conclusions 8. Acknowledgement 9. References
Fundamentals of Medicinal Biomagnetism
Health and Society, 2023
Medicinal Biomagnetism (MB) is a therapy for the prevention, diagnosis, and treatment of diseases using static magnetic fi elds. It is based on physical-chemical and physiopathological principles. To understand the technique, it is necessary to present the concepts of magnetism, potential of hydrogen, magnetic resonance, entropy, symbiosis, homeostasis, and the rheology of fl uids. Understanding the fundamentals of MB is 312 g , , the fi rst step towards the construction of a scientifi c language, as well as for the understanding and clinical interpretation of its results. This study is a narrative review of the literature that aims to present the fundamentals of MB within the principles of physics, chemistry, biology, physiology, and biochemistry to serve as a basis for technique application and for new scientifi c research projects in the area. Most of the studies that have applied the technique could not be considered for analysis due to a lack of the necessary methodological rigor, while others were derived from end-of-course papers and are not yet published. Regarding the investigated fundamentals, a vast body of literature was found, and its relationship with MB can be explored. It is concluded that there is coherence between the theoretical bases already substantiated in science and the principles of MB.