A suitable plane transmission line at 900MHz rf fields for E. coli DNA studies

Utilizing a suitable irradiating transmission line chamber, the effects of 900MHz radio frequency fields on DNA mutability and repair in Escherichia coli strains were investigated. The transmission line was very versatile and able to easily apply different field values. In this experiment the maximum electric and magnetic fields were 66V∕m and 260nT, respectively, in the absence of cell plates. Slight decrease in spontaneous mutability to erythromycin resistance was demonstrated in mismatch-repair proficient bacteria exposed to the radio frequency electromagnetic field (RF-EMF) during their growth on solid medium. The anti-mutagenic effect of the RF-EMF was much more impressive at the level of a hypermutagenic cytosine repeat, whose stability is strongly dependent on the activity of the mismatch repair system. In contrast, in mismatch repair-defective background RF-EMF neither affected the general DNA mutability nor the stability of the cytosine repeat, suggesting that the anti-mutagenic effect of the 900...

[1]  J. Bernhardt,et al.  Non-ionizing radiation safety: radiofrequency radiation, electric and magnetic fields , 1992, Physics in medicine and biology.

[2]  H. Lai,et al.  Acute low-intensity microwave exposure increases DNA single-strand breaks in rat brain cells. , 1995, Bioelectromagnetics.

[3]  A. Guy,et al.  "A quarter century of in vitro research: A new look at exposure methods" , 1999, Bioelectromagnetics.

[4]  George L. Carlo,et al.  Wireless Phones and Health , 1998, Springer US.

[5]  H. Lai,et al.  Single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation. , 1996, International journal of radiation biology.

[6]  M. Winkler,et al.  Negative regulation of mutS and mutH repair gene expression by the Hfq and RpoS global regulators of Escherichia coli K-12 , 1997, Journal of bacteriology.

[7]  Myron L. Crawford,et al.  Generation of Standard EM Fields Using TEM Transmission Cells , 1974 .

[8]  Magnetic field exposure stimulates transposition through the induction of DnaK/J synthesis. , 2000, Biochemical and biophysical research communications.

[9]  Dariusz Leszczynski,et al.  Non-thermal activation of the hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial cells: molecular mechanism for cancer- and blood-brain barrier-related effects. , 2002, Differentiation; research in biological diversity.

[10]  H. Lai,et al.  Melatonin and a spin-trap compound block radiofrequency electromagnetic radiation-induced DNA strand breaks in rat brain cells. , 1997, Bioelectromagnetics.

[11]  P. Alifano,et al.  Hypermutation in pathogenic bacteria: frequent phase variation in meningococci is a phenotypic trait of a specialized mutator biotype. , 1999, Molecular cell.

[12]  H. Fröhlich.  Long-range coherence and energy storage in biological systems , 1968 .

[13]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[14]  D. McRee,et al.  Genotoxicity of radiofrequency signals. I. Investigation of DNA damage and micronuclei induction in cultured human blood cells , 2002, Bioelectromagnetics.

[15]  R. Waldron.  Theory of guided electromagnetic waves , 1970 .

[16]  S F Cleary,et al.  Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation. , 1997, Bioelectromagnetics.

[17]  N. C. Wyeth,et al.  Alterations in the structure of the electrical double layer adjacent to a charged membrane arising from electromagnetically induced changes in the activity of membrane bound enzymes , 1985, Cell Biophysics.

[18]  K Chow,et al.  Magnetic field exposure enhances DNA repair through the induction of DnaK/J synthesis , 2000, FEBS letters.

[19]  L. Verschaeve,et al.  Genetic, carcinogenic and teratogenic effects of radiofrequency fields. , 1998, Mutation research.

[20]  H. Fröhlich.  Long Range Coherence and the Action of Enzymes , 1970, Nature.

[21]  N Kuster,et al.  Effect of global system for mobile communication microwave exposure on the genomic response of the rat brain , 1997, Neuroscience.

[22]  A. Jackson,et al.  Induction of microsatellite instability by oxidative DNA damage. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[23]  R. S. Harris,et al.  Mismatch repair protein MutL becomes limiting during stationary-phase mutation. , 1997, Genes & development.

[24]  Samuel A. Goldblith,et al.  DIELECTRIC PROPERTIES AT MICROWAVE FREQUENCIES OF AGAR GELS. , 1975 .

[25]  H. Nojima,et al.  High efficiency transformation of Escherichia coli with plasmids. , 1990, Gene.

[26]  S. Rosenberg,et al.  Adaptive mutation and amplification in Escherichia coli: two pathways of genome adaptation under stress. , 2004, Research in microbiology.