Study type: Medical/biological study (experimental study)

Resonance effect of microwaves on the genome conformational state of E. coli cells. med./bio.

Published in: Zeitschrift für Naturforschung. A, A Journal of Physical Sciences 1992; 47 (7-8): 621-627

Aim of study (acc. to author)

The influence of millimeter waves on the process of the genome conformational state (GCS) repair after E. coli cell exposure to X-rays was examined.

Background/further details

As a test for appearance and repair of changes in a chromosomal DNA the method of the anomalous viscosity time dependencies (AVTD) in cell lysates was used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 51.62–51.84 GHz
Exposure duration: 90 min
Exposure 2: 41.25–41.5 GHz
Exposure duration: 10 min
Exposure 3: 51.62–51.84 GHz
Exposure duration: 15 min
Exposure 4: 41.25–41.5 GHz
Exposure duration: 5 min
Exposure 5: 51.78 GHz
Exposure duration: 30 min

Exposure 1

Main characteristics
Frequency 51.62–51.84 GHz
Exposure duration 90 min
Exposure setup
Exposure source
Setup E.coli cell suspension irradiated in 50 mm diameter Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
power density 30 W/m² unspecified measured - -
SAR 17 mW/g - estimated cf. remarks acoustic method
SAR 22 mW/g - estimated cf. remarks calorimetric method

Exposure 2

Main characteristics
Frequency 41.25–41.5 GHz
Exposure duration 10 min
Exposure setup
Exposure source
Setup E.coli cell suspension irradiated in 50 mm diameter Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
power density 2 W/m² unspecified measured - -

Exposure 3

Main characteristics
Frequency 51.62–51.84 GHz
Exposure duration 15 min
Exposure setup
Exposure source
Setup E.coli cell suspension irradiated in 50 mm diameter Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
power density 30 W/m² unspecified measured - -

Exposure 4

Main characteristics
Frequency 41.25–41.5 GHz
Exposure duration 5 min
Exposure setup
Exposure source
Setup E.coli cell suspension irradiated in 50 mm diameter Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
power density 1 µW/cm² minimum measured - -

Exposure 5

Main characteristics
Frequency 51.78 GHz
Exposure duration 30 min
Exposure setup
Exposure source
Setup E.coli cell suspension irradiated in 50 mm diameter Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
power density 30 W/m² unspecified measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Radiation of E. coli cells with doses of 10-50 Gy led to changes of the AVTD curve of the cell lysate. After post-irradiated cell incubation of 90-120 min (depending on the dose of radiation), an almost complete recovery of the AVTD curve took place. This means that during this period the genome conformational state of the exposed cells returned to the control level ("repair" of genome conformational state).
The "repair" of genome conformational state of bacterial cells after ionizing irradiation is highly sensitive to the resonance effect of millimeter waves (microwaves suppress the "repair"): Within the ranges of 51.62-51.84 GHz and 41.25-41.50 GHz the frequency dependence of the observed effect has a resonance nature. The power dependence of the microwave effect within the range of 0.1-200 µW/cm² has shown that a power density of 1 µW/cm² is sufficient to suppress radiation-induced repair of the genome conformational state. The effect of microwave suppression of repair does not depend on the sequence of cell exposure to X-rays and microwave radiation.
The data indicate the role of the cell genome in the resonant interaction of cells with low intensity millimeter waves.

Study character:

Study funded by

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