Study type: Therapeutical study (experimental study)

The effect of 100 Hz magnetic field combined with X-ray on hepatoma-implanted mice. med./bio.

Published in: Bioelectromagnetics 2011; 32 (4): 322-324

Aim of study (acc. to author)

To study the possible synergism between 100 Hz magnetic field exposure and X-rays in terms of their influence on tumor growth inhibition and survival time in tumor-bearing mice.

Background/further details

Implanted tumors were allowed to grow for 7-14 days until the tumor diameter reached the size of 2 cm before treatment was started.
Mice were divided into six groups (n = 10): 1) sham X-ray and five periods of sham exposure to magnetic field (each period = 60 min with an interval of 12 h); 2) sham X-ray and five periods of 100 Hz magnetic field exposure; 3) 4 Gy X-ray followed (within half an hour) by five periods of sham exposure to magnetic fields; 4) 8 Gy X-ray followed by five periods of sham exposure; 5) 4 Gy X-rays followed by five periods of magnetic field exposure; and 6) 8 Gy X-ray followed by five periods of magnetic field exposure.
Additionally, to study whether more magnetic field exposure periods could have a greater synergistic effect with X-rays than fewer periods, three groups of tumor-bearing mice were examined (n = 20): 1) 4 Gy X-rays followed by five periods of sham exposure; 2) 4 Gy X-ray followed by three periods magnetic field exposure and two periods of sham exposure; and 3) 4 Gy X-rays followed by five periods of magnetic field exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 100 Hz
Exposure duration: 3 or 5 times 60 min with a 12 h interval between them

Exposure 1

Main characteristics
Frequency 100 Hz
Type
Waveform
Exposure duration 3 or 5 times 60 min with a 12 h interval between them
Additional info animals were treated in different groups: i) sham X-ray exposure + 5 times sham EMF exposure ii) sham X-ray exposure + 5 times EMF exposure iii) 4 Gy X-ray exposure + 5 times sham EMF exposure iv) 8 Gy X-ray exposure + 5 times sham EMF exposure v) 4 Gy X-ray exposure + 5 times EMF exposure vi) 8 Gy X-ray exposure + 5 times EMF exposure vii) 4 Gy X-ray exposure + 3 times EMF exposure + 2 times sham EMF exposure
Exposure setup
Exposure source
Setup 15 cm x 20 cm solenoid with 270 turns of 2 mm diameter copper wire wound in three layers; mouse anesthetized and placed inside the solenoid
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.7 mT mean measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The data showed that five periods of combined 100 Hz magnetic field exposure and 4 Gy X-ray could significantly extend the overall days of survival and reduce the tumor size compared to magnetic field exposure or X-ray alone. Furthermore, a greater number of magnetic field exposure periods (5 compared to 3) could further improve the survival and inhibit tumor growth in hepatoma-implanted mice when combined with 4 Gy X-ray.
In conclusion, these findings suggest that 100 Hz magnetic fields could possibly synergize with 4 Gy X-ray in terms of survival improvement and tumor inhibition in hepatoma-implanted mice.

Study character:

Study funded by

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