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Askaripour K, Żak A. A systematic review on cellular responses of Escherichia coli to nonthermal electromagnetic irradiation. Bioelectromagnetics 2024; 45:16-29. [PMID: 37807247 DOI: 10.1002/bem.22484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 06/23/2023] [Accepted: 08/07/2023] [Indexed: 10/10/2023]
Abstract
Investigation of Escherichia coli under electromagnetic fields is of significance in human studies owing to its short doubling time and human-like DNA mechanisms. The present review aims to systematically evaluate the literature to conclude causality between 0 and 300 GHz electromagnetic fields and biological effects in E. coli. To that end, the OHAT methodology and risk of bias tool were employed. Exponentially growing cells exposed for over 30 min at temperatures up to3 7 ∘ C $3{7}^{\circ }\,{\rm{C}}$ with fluctuations below1 ∘ C ${1}^{\circ }\,{\rm{C}}$ were included from the Web-of-Knowledge, PubMed, or EMF-Portal databases. Out of 904 records identified, 25 articles satisfied the selection criteria, with four excluded during internal validation. These articles examined cell growth (11 studies), morphology (three studies), and gene regulation (11 studies). Most experiments (85%) in the included studies focused on the extremely low-frequency (ELF) range, with 60% specifically at 50 Hz. Changes in growth rate were observed in 74% of ELF experiments and 71% of radio frequency (RF) experiments. Additionally, 80% of ELF experiments showed morphology changes, while gene expression changes were seen in 33% (ELF) and 50% (RF) experiments. Due to the limited number of studies, especially in the intermediate frequency and RF ranges, establishing correlations between EMF exposure and biological effects on E. coli is not possible.
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Affiliation(s)
- Khadijeh Askaripour
- Department of Biomechatronics, Gdansk University of Technology, Gdansk, Pomorskie, Poland
| | - Arkadiusz Żak
- Department of Biomechatronics, Gdansk University of Technology, Gdansk, Pomorskie, Poland
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2
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Rashidieh B, Ansari AM, Behdani M, Darvishi B, Habibi-Anbouhi M. Extremely low frequency magnetic field enhances expression of a specific recombinant protein in bacterial host. Anal Biochem 2022; 652:114745. [DOI: 10.1016/j.ab.2022.114745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/10/2022] [Accepted: 05/18/2022] [Indexed: 11/29/2022]
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Greenebaum B. Answers and Questions: Forty Years in Bioelectromagnetics. Bioelectromagnetics 2021; 43:47-63. [PMID: 34859455 DOI: 10.1002/bem.22381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 11/10/2022]
Abstract
The work began in 1972 when three young assistant professors used a slime mold to see if electromagnetic fields would affect it. The fields did, though the effects were small and hard to tease out of the noise. The cell cycle was lengthened and there were changes in respiration. So, the next question was "how and why?" Further changes were seen using these and then other bacterial and eukaryotic cells in respiration, in ATP, in the protein replication chain, and so forth. Changes occurred even in cell extracts that lacked an intact plasma membrane. Nerve cells showed changes in leakage of neurotransmitters and in neurite outgrowth from excised ganglia. Based on some experiments with nerve cells, I also did some computer calculations, modeling the internal electric and magnetic fields and current densities in simplified representations of bone fractures and also of spinal cords in vertebrae. More recently, I have collaborated on some theoretical models of what fields might be doing at the cellular and molecular level, particularly with reference to the radical model. With each piece of research, my collaborators and I generally found a small piece of information about fields and biological systems; and each answer raised another set of questions, which is the way of science. Though bioelectromagnetic scientists have learned much and can say much at greater depth about what happens when an organism is exposed to a field, the fundamental question still remains: What exactly is going on here? © 2021 Bioelectromagnetics Society.
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Affiliation(s)
- Ben Greenebaum
- Physics Department, University of Wisconsin-Parkside, Kenosha, Wisconsin
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4
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Al-Harbi FF, Alkhalifah DHM, Elqahtani ZM, Ali FM, Mohamed SA, Abdelbacki AMM. Nonthermal control of Escherichia coli growth using extremely low frequency electromagnetic (ELF-EM) waves. Biomed Mater Eng 2019; 29:809-820. [PMID: 30282336 DOI: 10.3233/bme-181025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and the treatment of the infection could be achieved by using antibiotics, however the effectiveness is still debatable and needs more investigation. OBJECTIVE Researching the inhibition resonance frequency of square amplitude modulating waves (QAMW) that can inhibit the growth activity of E. coli and its ability to make division. METHODS A range of different extremely low frequencies of square amplitude modulated waves (QAMW) from 0.1 to 1.0 Hz from two generators with a constant carrier frequency of 10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength 200 V/m were used to treat E. coli cells at 37 °C. RESULTS The exposure of E. coli to 0.3 Hz QAMW for 90 min was the most inhibited frequency where the bacterial growth inhibited by 42.3%. Furthermore, a significant increase in antibiotic susceptibility to protein and cell wall inhibitors was investigated. Also, results of the chromosomal DNA sequences, dielectric relaxation and TEM indicated highly significant molecular and morphological changes after the exposure. CONCLUSIONS We concluded that the exposure of E. coli to QAMW at the inhibiting frequency interfered with the bioelectric signals generated from the bacteria during the cell division and changed the cellular activity and DNA sequences, and these changes lead to a significant inhibition of the bacterial growth. This is a new promising technique that aids to avoid the repetitive use of antibiotics against the bacterial pathogens.
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Affiliation(s)
- F F Al-Harbi
- Physics Department, Faculty of Science, Princess Nourah bint Abdulrahman University, Kingdom of Saudi Arabia
| | - Dalal H M Alkhalifah
- Biology Department, Faculty of Science, Princess Nourah bint Abdulrahman University, Kingdom of Saudi Arabia
| | - Zainab M Elqahtani
- Physics Department, Faculty of Science, Princess Nourah bint Abdulrahman University, Kingdom of Saudi Arabia
| | - Fadel M Ali
- Biophysics Department, Faculty of Science, Cairo University, Egypt
| | | | - A M M Abdelbacki
- Plant Pathology Department, Faculty of Agriculture, Cairo University, Egypt
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Fadel MA, El-Gebaly RH, Mohamed SA, Abdelbacki AMM. Biophysical control of the growth of Agrobacterium tumefaciens using extremely low frequency electromagnetic waves at resonance frequency. Biochem Biophys Res Commun 2017; 494:365-71. [PMID: 28988110 DOI: 10.1016/j.bbrc.2017.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 10/02/2017] [Indexed: 11/23/2022]
Abstract
Isolated Agrobacterium tumefaciens was exposed to different extremely low frequencies of square amplitude modulated waves (QAMW) from two generators to determine the resonance frequency that causes growth inhibition. The carrier was 10 MHz sine wave with amplitude ±10 Vpp which was modulated by a second wave generator with a modulation depth of ± 2Vpp and constant field strength of 200 V/m at 28 °C. The exposure of A. tumefaciens to 1.0 Hz QAMW for 90 min inhibited the bacterial growth by 49.2%. In addition, the tested antibiotics became more effective against A. tumefaciens after the exposure. Furthermore, results of DNA, dielectric relaxation and TEM showed highly significant molecular and morphological changes due to the exposure to 1.0 Hz QAMW for 90 min. An in-vivo study has been carried out on healthy tomato plants to test the pathogenicity of A. tumefaciens before and after the exposure to QAMW at the inhibiting frequency. Symptoms of crown gall and all pathological symptoms were more aggressive in tomato plants treated with non-exposed bacteria, comparing with those treated with exposed bacteria. We concluded that, the exposure of A. tumefaciens to 1.0 Hz QAMW for 90 min modified its cellular activity and DNA structure, which inhibited the growth and affected the microbe pathogenicity.
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Atak Ç, Çelik Ö, Olgun A, Alikamanoğlu S, Rzakoulieva A. Effect of Magnetic Field on Peroxidase Activities of Soybean Tissue Culture. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2007.10817438] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Tagourti J, El May A, Aloui A, Chatti A, Ben Aissa R, Landoulsi A. Static magnetic field increases the sensitivity of Salmonella to gentamicin. ANN MICROBIOL 2010. [DOI: 10.1007/s13213-010-0081-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Schwenzer NF, Bantleon R, Maurer B, Kehlbach R, Schraml C, Claussen CD, Rodegerdts E. Do static or time-varying magnetic fields in magnetic resonance imaging (3.0 T) alter protein-gene expression?-A study on human embryonic lung fibroblasts. J Magn Reson Imaging 2008; 26:1210-5. [PMID: 17969170 DOI: 10.1002/jmri.21145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To evaluate the influence of magnetic resonance imaging (MRI) on gene expression in embryonic human lung fibroblasts (Hel 299). MATERIALS AND METHODS The cells were exposed to the static magnetic field and to a turbo spin-echo sequence of an MR scanner at 3.0 Tesla. An MR group (exposed) and a control group (sham-exposed) were set up using a special MR-compatible incubation system. The exposure time was two hours. Gene expression profiles were studied using a complementary deoxyribonucleic acid (cDNA) microarray containing 498 known genes involved in transcription, intracellular transport, structure/junction/adhesion or extracellular matrix, signaling, host defense, energetics, metabolism, cell shape, and death. RESULTS No changes in gene expression were found in either group (exposed or sham-exposed cells) at the end of a two-hour exposure for any of the 498 tested protein genes. CONCLUSION The results suggest that MRI has no influence on protein-gene expression in eugenic human lung cells.
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Affiliation(s)
- Nina F Schwenzer
- Department of Diagnostic Radiology, Eberhard-Karls University, Tübingen, Germany.
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Potenza L, Ubaldi L, De Sanctis R, De Bellis R, Cucchiarini L, Dachà M. Effects of a static magnetic field on cell growth and gene expression in Escherichia coli. Mutat Res 2004; 561:53-62. [PMID: 15238230 DOI: 10.1016/j.mrgentox.2004.03.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2003] [Revised: 03/08/2004] [Accepted: 03/19/2004] [Indexed: 10/26/2022]
Abstract
Escherichia coli cultures exposed to a 300mT static magnetic field (SMF) were studied in order to analyse possible induced changes in cellular growth and gene expression. Biomass was evaluated by visible-light spectrometry and gene expression analyses were carried out by use of RNA arbitrarily primed PCR. The bacterial strain XL-1Blue, cultivated in traditional and modified Luria-Bertani medium, was exposed to SMF generated by permanent neodymium magnetic disks. The results show alterations induced by SMF in terms of increased cell proliferation and changes in gene expression compared with control groups. Three cDNAs were found to be expressed only in the exposed cells, whereas one cDNA was more expressed in the controls. One clone, expressed only in the exposed cells, corresponds to a putative transposase. This is of particular interest in that it suggests that exposure to a magnetic field may stimulate transposition activity.
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Affiliation(s)
- Lucia Potenza
- Giorgio Fornaini Institute of Biological Chemistry, University of Urbino Carlo Bo, 61029 Urbino, PU, Italy.
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11
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Abstract
Low frequency (< 300 Hz) electromagnetic (EM) fields induce biological changes that include effects ranging from increased enzyme reaction rates to increased transcript levels for specific genes. The induction of stress gene HSP70 expression by exposure to EM fields provides insight into how EM fields interact with cells and tissues. Insights into the mechanism(s) are also provided by examination of the interaction of EM fields with moving charges and their influence on enzyme reaction rates in cell-free systems. Biological studies with in vitro model systems have focused, in general, on the nature of the signal transduction pathways involved in response to EM fields. It is likely, however, that EM fields also interact directly with electrons in DNA to stimulate biosynthesis. Identification of an EM field-sensitive DNA sequence in the heat shock 70 (HSP70) promoter, points to the application of EM fields in two biomedical applications: cytoprotection and gene therapy. EM field induction of the stress protein hsp70 may also provide a useful biomarker for establishing a science-based safety standard for the design of cell phones and their transmission towers.
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Affiliation(s)
- Reba Goodman
- Department of Pathology, Columbia University Health Sciences, New York, New York, USA
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Laitl-Kobierska A, Cieślar G, Sieroń A, Grzybek H. Influence of alternating extremely low frequency ELF magnetic field on structure and function of pancreas in rats. Bioelectromagnetics 2002; 23:49-58. [PMID: 11793405 DOI: 10.1002/bem.97] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The aim of this study was to estimate the influence on ultrastructure and function of endocrine and excretoric part of pancreas in rats of extremely low frequency alternating magnetic fields with parameters used in therapy in humans. The animals from the two experimental groups were exposed to a rectangular magnetic field waveform at a frequency of 10 Hz and induction of 1.8-3.8 mT--(group P) or a sinusoidal magnetic field at a frequency of 40 Hz and induction of 1.3-2.7 mT--(group S), respectively. The control rats were subjected to sham exposure. The cycle of 1, 3, 6, 9, and 14 daily exposure sessions lasting 30 min was made in all groups. Some of rats after finishing the cycle of 14 exposures were left in the same conditions except for the magnetic field for 3 or 10 days. In both groups of rats exposed to magnetic field, a distinct tendency to decrease glucose concentration, compared to control group, was observed during the exposure cycle. Serum glucose became normal after the end of exposure sessions. The concentrations of insulin in both groups of rats exposed to magnetic field were significantly higher, compared to the controls, during the exposure cycle. After the end of exposure cycle the concentration of insulin in group S became normal. In contrast, in group P the concentration of insulin decreased significantly on the last day of exposure, with a subsequent increase in the following days. The activity of alpha-amylase and lipase in the serum of experimental and control rats was not affected. In both groups of exposed rats, reversible changes of ultrastructure of the pancreatic islets, including expansion of the Golgi apparatus, extension of rough endoplasmatic reticulum, mitochondrial swelling, expansion of beta-granules and increase in number of empty vesicles in beta cells, occurred during the exposure. In acinar cells of exposed animals, a slight extension of rough endoplasmatic reticulum and mitochondrial swelling as transitory changes were observed. The structural and functional changes in pancreas are probably adaptative ones.
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Affiliation(s)
- Anna Laitl-Kobierska
- Chair and Clinic of Internal Diseases and Physical Medicine, Silesian Medical University, Bytom, Poland
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13
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Grzesiuk E, Zabielski R. Chapter 25 Electric fields and currents of the small intestine and their effects on Escherichia coli. Biology of the Intestine in Growing Animals. Elsevier; 2002. pp. 727-49. [DOI: 10.1016/s1877-1823(09)70141-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Wójcik-Sikora A, Laubitz D, Pierzynowski SG, Grzesiuk E. Exposure of Escherichia coli to intestinal myoelectrical activity-related electric field induces resistance against subsequent UV(254 nm) (UVC) irradiation. Mutat Res 2001; 496:97-104. [PMID: 11551485 DOI: 10.1016/s1383-5718(01)00212-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Survival of Escherichia coli K-12 AB1157 irradiated with UVC (UV(254 nm)) was enhanced after pre-treatment with a low-tension electric field (EF). The EF used was identical to the electrical field generated by the small intestine (myoelectrical migrating complex--MMC), registered in a healthy calf and transmitted into the memory of an EF generator. The EF emitted by the generator was transmitted via electrodes placed in shaken bacterial cultures. The protective effects of the EF on the E. coli survival after exposure to UV were: (i) observed only for the dnaJ(+)dnaK(+) strain, and not for the DeltadnaJdnaK heat shock mutant; (ii) strictly dependent on the temperature at which the bacteria were grown; (iii) most obvious when the bacteria were incubated at 37 degrees C. Moreover, the MMC-related EF and a higher temperature (40 degrees C) show a similar protective effect against UV-irradiation. The results point to the involvement of the heat shock response in the low-tension EF-induced protection of bacterial cells against UVC-irradiation. Additionally, treatment with the MMC-related EF affects total protein contents and their pattern in E. coli cells. The EF-treatment did not show any influence on the level of the argE3(ochre) --> Arg(+) reversions.
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Affiliation(s)
- A Wójcik-Sikora
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, PAS, Pawinskiego 5A, 02-106, Warsaw, Poland
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15
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Abstract
Magnetic fields (MFs) of various characteristics can lead to plethora effects in biological system. From a molecular point of view, we hypothesized that there must be a fundamental difference in gene expression between the MF exposed and the unexposed cell. To identify the classes of genes that are regulated, 0.8 mT 50 Hz MF-induced changes in gene expression were examined in a Daudi cell culture using differential display and reverse transcriptase-polymerase chain reaction. A candidate cDNA (signatured as MF-CB) that was observed in the sham-exposed but not in MF-exposed cultures was recovered and reamplified. After verification by Northern blot, the cDNA was cloned and sequenced. It was found that 254-base pair of 5'-end MF-CB cDNA clone was identical to gcs in open reading frame (ORF) range. Based on the preliminarily sequence, the prolonged length of 5'-end MF-CB cDNA was obtained by PCR amplification and its sequence analysis showed the same results as its original fragment. In order to further determine whether MF-CB cDNA is from gcs, two Northern blots were probed with gcs and MF-CB cDNA, respectively, and the data revealed signals of the same size and expression pattern on the two probe filters, which demonstrated that MF-CB is an EST (expression sequence tag) of gcs. gcs is a gene, identified recently (GenBank accession number D89866), encoding ceramide glucosyltransferase (GCS), which has been implicated as a causal element in human cell growth and differentiation. In an additional experiment, time-dependent changes in the transcription of gcs induced by 0.8 mT MF were observed by Northern blot with a sharp and reproducible inhibition effect after 20 min exposure and a reduction after 20-24 h exposure. The study demonstrates for the first time that 50 Hz MF can lead to changes in gcs transcription, which provides a new clue to elucidate the mechanism by which MF influence cell growth and differentiation.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Northern
- Burkitt Lymphoma/genetics
- Burkitt Lymphoma/pathology
- Cloning, Molecular
- DNA, Complementary/genetics
- Enzyme Induction/radiation effects
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic/radiation effects
- Glucosyltransferases/biosynthesis
- Glucosyltransferases/genetics
- Humans
- Magnetics
- Molecular Sequence Data
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Polymerase Chain Reaction
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Sequence Homology, Nucleic Acid
- Subtraction Technique
- Transcription, Genetic/radiation effects
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/radiation effects
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Affiliation(s)
- R Y Wu
- Microwave Lab, Medical College, Zhejiang University, Hangzhou 310031, P.R. China
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Abstract
Escherichia coli K12 was used as a model system to determine whether ELF magnetic fields (MFs) are a general stress factor. The cells were exposed to ELF MFs (5-100 Hz) at a maximum intensity of 14 mT r. m.s. for circularly polarized MFs and 10 mT r.m.s. for vertically polarized MFs. The response of the cells to the MFs was estimated from the change in protein synthesis by using 2D PAGE. Approximately 1,000 proteins were separated on the 2D gels. The stress-responsive proteins such as CH10, DNAK, CH60, RECA, USPA, K6P1 and SODM were identified from the SWISS-2DPAGE database on the 2D gels. These proteins respond to most stress factors, including temperature change, chemical compounds, heavy metals, and nutrients. When the bacterial cells were exposed to each MF at 5-100 Hz under aerobic conditions (6.5 h) or at 50 Hz under anaerobic conditions (16 h) at the maximum intensity (7.8 to 14 mT r.m.s.), no reproducible changes were observed in the 2D gels. Changes in protein synthesis were detected by 2D PAGE with exposure to heat shock (50 degrees C for 30 min) or under anaerobic conditions (no bubbling for 16 h). Increases in the levels of synthesis of the stress proteins were observed in heat-shocked cells (CH60, CH10, HTPG, DNAK, HSLV, IBPA and some unidentified proteins) and in cells grown under anaerobic conditions (DNAK, PFLB, RECA, USPA and many unidentified proteins). These results suggest that 2D PAGE is sufficient to detect cell responses to environmental stress. The high-intensity ELF MFs (14 mT at power frequency) did not act as a general stress factor.
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Affiliation(s)
- S Nakasono
- Bio-Science Department, Abiko Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-City, Chiba 270-1194, Japan
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17
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Abstract
The mechanisms whereby electromagnetic (EM) fields stimulate changes in biosynthesis in cells are not known. It has has generally been assumed that EM fields first interact with cell membranes, but this pathway may not be only one. Interactions with membranes are well documented, but recent studies of EM signal transduction in the membrane Na,K-ATPase are best explained by direct interaction of electric and magnetic fields with mobile charges within the enzyme. Interaction with moving charges may be a mechanism that is operative in other biopolymers. Recent studies on DNA have shown that large electron flows are possible within the stacked base pairs of the double helix. Therefore, gene activation by magnetic fields could be due to direct interaction with moving electrons within DNA. Electric fields as well as magnetic fields stimulate transcription, and both fields could interact with DNA directly. The mechanism of EM field-stimulated transcription may be related to the process in striated muscles, where endogenous electrical activity induces the synthesis of new proteins.
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Affiliation(s)
- M Blank
- Department of Physiology, Columbia University, New York, NY 10032, USA
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18
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Abstract
It has been suggested that electromagnetic (EM) fields can act as co-promoters during neoplastic transformation. To examine this possibility, we studied the effects of 0.8-, 8-, 80-, and 300-microT 60-Hz electromagnetic (EM) fields in INITC3H/10T1/2 mouse fibroblast cells. These cells are transformed carcinogenically by methylcholanthrene, but the neoplastic phenotype can be suppressed indefinitely by the presence of retinyl acetate (RAC) in the culture medium. The effects of EM field exposures were examined at three stages: (1) before initiation of transformation (i.e., RAC in the culture media); (2) early in the transformation process (4 days after withdrawal of RAC); and (3) at full of neoplastic transformation (10 days after withdrawal of RAC). EM field exposures induced significant increases in protein levels for hsp70 and c-Fos and in AP-1 binding activity. EM fields induced phosphorylation of MAPK/ERK1/2 before the onset of transformation, but these increases diminished during the transformation process. No phosphorylation in the other major extracellular stress pathway, SAPK/JNK, was detected in cells exposed to EM fields at any time before, during, or after neoplastic transformation. Human cells HL60, MCF7, and HTB124, exposed to EM fields, also showed MAPK/ERK1/2 phosphorylation. Cells treated with the phorbol ester, TPA, served as positive controls for AP-1 activation, c-Fos protein synthesis, and ERK1/2 phosphorylation. There was no indication that EM fields affected the rate of cell transformation or acted as a co-promoter, under the conditions of this study.
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Affiliation(s)
- M Jin
- Department of Pathology, Columbia University, New York, NY 10032, USA
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19
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Abstract
Biological assays often suffer from large systematic variation between sets of experiments. This variation is sometimes countered by normalizing the results of an "exposed" (E) experiment to that of a simultaneously performed "control" (C). We demonstrate that the arithmetic mean of such ratios overestimates the "true" E/C ratio. Fortunately, the overestimation may be calculated from experimentally accessible information, and it is generally possible to correct for this factor using formulas presented in this paper. We have studied the impact of this effect on a set of studies in the bioelectromagnetics literature and find that, although most results are weakened by the correction, few are significantly altered. Some of the papers used for our literature study are controversial; we believe that the present study may strengthen the quoted results by removing doubts about the statistical treatment of E/C ratios. Both false positives and negatives are possible if the proper correction is not made to the arithmetic mean of a set of E/C data. Realistic examples of erroneous statistical conclusions demonstrate that this is a real concern for E/C data which are marginal in both magnitude (mean < 2) and variance (standard deviation > 0.5).
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Affiliation(s)
- S Engström
- Biomedical Sciences, University of California, Riverside, USA.
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Felaco M, Reale M, Grilli A, De Lutiis MA, Barbacane RC, Di Luzio S, Conti P. Impact of extremely low frequency electromagnetic fields on CD4 expression in peripheral blood mononuclear cells. Mol Cell Biochem 1999; 201:49-55. [PMID: 10630622 DOI: 10.1023/a:1007004316433] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
There is increasing evidence suggesting that extremely low frequency electromagnetic fields (ELF-EMF) may influence several cell functions. Here the effects of ELF-EMF were studied on the expression of CD4+ cell surface receptors of human peripheral blood mononuclear cells (PBMC) using fluorescence-activated cell sorter (FACScan). The expression of CD4+ in ELF-EMF exposed (24, 48 and 72 h) and not exposed PBMC were not statistically significant. In addition, a flow cytometric analysis was determined by using a fluorescent labeled antibody, at 24 and 72 h incubations. The amount of bound antibody was distributed with a slight difference in the ELF-EMF-exposed PBMC compared to the not exposed cells. Moreover, DNA CD4+ expression in PBMC strongly increased in exposed cells, resting and activated with Phytohaemaglutinin (PHA). When polymerase chain reaction was performed on CD4+ mRNA of PBMC an increase of CD4+ mRNA expression was found after the resting cells were exposed to ELF-EMF at 24 h compared to not exposed cells, while at 48 and 72 h no difference was found. In the cell cycle progression analysis, the PBMC exposed to ELF-EMF presented a significant increase of percentage expression of cell cycle progression in the S phase compared to not exposed cells; while in G1 and G2 phases, there were no differences. Our results provide new evidence that ELF-EMF can affect CD4+ expression in PBMC and describe an additional biological activity for ELF-EMF affecting CD4+ transcription and translation protein and the increase of the percentage expression of the cell cycle progression of the S phase.
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Affiliation(s)
- M Felaco
- Department of Oncology and Neurosciences, University of Chieti, Medical School, Italy
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21
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Abstract
To develop an alternative to hyperthermia for the induction of hsp70 for presurgical cytoprotection, we investigated the optimal exposure conditions for magnetic field induction of hsp70. Normal human breast cells (HTB124) were exposed to 60-Hz magnetic fields and hsp70 levels were measured following three different exposure conditions: continuous exposure up to 3 h, a single 20-min exposure, and a single 20-min exposure followed by repeated 20-min exposures at different field strengths. In cells exposed continuously for 3 h, hsp70 levels peaked (46%) within 20 min and returned to control levels by 2 h. Following a single 20-min exposure, the return of hsp70 levels to control values extended to more than 3 h. When cells underwent a 20-min exposure followed by repeated 20-min exposures (restimulation) with different field strengths, additional increases in hsp70 levels were induced: 31% at 1 h, 41% at 2 h, and 30% at 3 h.
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Affiliation(s)
- L Han
- Department of Pathology, Columbia University Health Sciences, New York, New York 10032, USA
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23
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Abstract
Electrification in developed countries has progressively increased the mean level of extremely low-frequency electromagnetic fields (ELF-EMFs) to which populations are exposed; these humanmade fields are substantially above the naturally occurring ambient electric and magnetic fields of approximately 10(-4) Vm(-1) and approximately 10(-13) T, respectively. Several epidemiological studies have concluded that ELF-EMFs may be linked to an increased risk of cancer, particularly childhood leukemia. These observations have been reinforced by cellular studies reporting EMF-induced effects on biological systems, most notably on the activity of components of the pathways that regulate cell proliferation. However, the limited number of attempts to directly replicate these experimental findings have been almost uniformly unsuccessful, and no EMF-induced biological response has yet been replicated in independent laboratories. Many of the most well-defined effects have come from gene expression studies; several attempts have been made recently to repeat these key findings. This review analyses these studies and summarizes other reports of major cellular responses to EMFs and the published attempts at replication. The opening sections discuss quantitative aspects of exposure to EMFs and the incidence of cancers that have been correlated with such fields. The concluding section considers the problems that confront research in this area and suggests feasible strategies.
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Affiliation(s)
- A Lacy-Hulbert
- Department of Biochemistry, University of Cambridge, England.
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Pessina GP, Aldinucci C. Pulsed electromagnetic fields enhance the induction of cytokines by peripheral blood mononuclear cells challenged with phytohemagglutinin. Bioelectromagnetics 1998. [DOI: 10.1002/(sici)1521-186x(1998)19:8<445::aid-bem1>3.0.co;2-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Affiliation(s)
- P. Cairo
- Biomedical Research Institute, University of Wisconsin‐Parkside, Kenosha, Wisconsin 53141
| | - B. Greenebaum
- Biomedical Research Institute, University of Wisconsin‐Parkside, Kenosha, Wisconsin 53141
| | - E. Goodman
- Biomedical Research Institute, University of Wisconsin‐Parkside, Kenosha, Wisconsin 53141
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Tuinstra R, Greenebaum B, Goodman E. Effects of magnetic fields on cell-free transcription in E. coli and HeLa extracts. ACTA ACUST UNITED AC 1997; 43:7-12. [DOI: 10.1016/s0302-4598(97)00024-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Mittenzwey R, Süßmuth R, Mei W. Effects of extremely low-frequency electromagnetic fields on bacteria—the question of a co-stressing factor. ACTA ACUST UNITED AC 1996; 40:21-7. [DOI: 10.1016/0302-4598(95)00504-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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30
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Abstract
A number of studies have shown that exposures to environmental magnetic fields (MFs) increase cellular transcription and enhance DNA synthesis. However, little is known about the basic mechanisms underlying specific biological responses to MFs. We looked directly at the effect of MFs by using a cell-free rabbit globin cDNA synthesis system. cDNA synthesis reaction mixtures were placed in each of four exposure conditions and were tested simultaneously. Condition one was the control, with no exposure during either single-strand or double-strand synthesis (M-M-). The second condition was MF exposure only during single-strand synthesis (M+M-). The third condition was exposure only during double-strand synthesis (M-M+). The fourth condition was exposure during both single-strand and double-strand synthesis (M+M+). Results showed that cDNA synthesis was affected by 5-100 microT, 60 Hz MFs. Double-strand cDNA synthesis increased with MF exposure only during double-strand synthesis reactions (M-M+), and the greatest increase of double-strand cDNA synthesis was detected when MF exposure was at 10 microT, only during double-strand synthesis. Double-strand cDNA synthesis decreased when only single-strand synthesis reactions were exposed (M+M-; 100 microT). An increase of cDNA synthesis caused increased synthesis of rabbit globin cDNA and large-sized molecules. These results suggest that exposure to MF induced structural changes of synthesized cDNA, therefore altering the amount of cDNA. Our results show that environmental MFs can significantly alter cDNA synthesis in a cell-free system.
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Affiliation(s)
- E Hirakawa
- Department of Microbiology, University of Texas Health Science Center, San Antonio, USA
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Abstract
Evidence suggests that cell processes can be influenced by weak electromagnetic fields (EMFs). EMFs appear to represent a global interference or stress to which a cell can adapt without catastrophic consequences. There may be exceptions to this observation, however, such as the putative role of EMFs as promoters in the presence of a primary tumor initiator. The nature of the response suggests that the cell is viewing EMFs as it would another subtle environmental change. The age and state of the cell can profoundly affect the EMF bioresponse. There is no evidence that direct posttranscription effects occur as a result of EMF exposure. Although transcription alterations occur, no apparent disruption in routine physiological processes such as growth and division is immediately evident. What is usually observed is a transient perturbation followed by an adjustment by the normal homeostatic machinery of the cells. DNA does not appear to be significantly altered by EMF. If EMF exposure is associated with an increased risk of cancer, the paucity of genotoxic effects would support the suggestion that the fields act in tumor promotion rather than initiation. The site(s) and mechanisms of interaction remain to be elaborated. Although there are numerous studies and hypotheses that suggest the membrane represents the primary site of interaction, there are also several different studies showing that in vitro systems, including cell-free systems, are responsive to EMFs. The debate about potential hazards or therapeutic value of weak electromagnetic fields will continue until the mechanism of interaction has been clarified.
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Affiliation(s)
- E M Goodman
- Biomedical Research Institute, University of Wisconsin-Parkside, Kenosha 53141, USA
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33
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Abstract
Quantitative two-dimensional gel electrophoresis of proteins in E. coli exposed for 60 min to weak, pulsed magnetic fields (1.5 mT peak) show that numerous proteins are both increased and decreased by a factor of 2 or more. An increase in the levels of two proteins, the a subunit of DNA-dependent RNA polymerase and NusA, was confirmed by Western blot analysis.
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Affiliation(s)
- E M Goodman
- Biomedical Research Institute, University of Wisconsin-Parkside, Kenosha 53141
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