Study type: Medical/biological study (experimental study)

Multifractal dimension and lacunarity of yolk sac vasculature after exposure to magnetic field. med./bio.

Published in: Microvasc Res 2015; 99: 1-7

Aim of study (acc. to author)

It should be investigated if lacunarity and multifractal dimension analyses are suitable to measure the effects of exposure of embryos of the Japanese quail (Coturnix japonica) to a 60 Hz magnetic field on the development of the vascular system in the yolk sac membrane.

Background/further details

The study was based on Costa et al. 2013 and should refine the method of the monofractal analysis.
100 eggs of the Japanese quail were divided into 5 groups (n=20 each): 1) sham exposure, exposure to the magnetic field 2) for 3 x 2 h/day, 3) for 3 x 3 h/day, 4) for 3 x 4 h/day and 5) for 24 h/day. 48 hours after the eggs had been laid, a small part of the egg shell was removed and replaced by transparent foil for observation and exposure started afterwards.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous for 2 h, 3 times a day with intervals of 6 hours in between for 2 days
Exposure 2: 60 Hz
Exposure duration: continuous for 3 h, 3 times a day with intervals of 5 hours in between for 2 days
Exposure 3: 60 Hz
Exposure duration: continuous for 4 h, 3 times a day with intervals of 4 hours in between for 2 days
Exposure 4: 60 Hz
Exposure duration: continuous for 24 h for 2 days

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for 2 h, 3 times a day with intervals of 6 hours in between for 2 days
Exposure setup
Exposure source
Setup Helmholtz coils were placed in an incubator; probes of the teslameter were placed on the horizontal axis of each coil; eggs were placed along the horizontal axis between the two coils
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for 3 h, 3 times a day with intervals of 5 hours in between for 2 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Exposure 3

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for 4 h, 3 times a day with intervals of 4 hours in between for 2 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Exposure 4

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for 24 h for 2 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Reference articles

  • Costa EV et al. (2013): Fractal analysis of extra-embryonic vascularization in Japanese quail embryos exposed to extremely low frequency magnetic fields.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

After 1 day of exposure, lacunarity of the vascular system was significantly higher in group 3 (3 x 3 h/day of exposure) compared to the sham exposure group. The multifractal analysis showed significant differences in the generalized dimensions spectrum in groups 2 (3 x 2 hours/day of exposure) and 3 compared to the sham exposure group after 1 day of exposure. Both results indicate differences in the development of the vascular system in the respective exposure groups compared to the sham exposure group.
Moreover, in all groups a dominance of the higher generalized dimensions could be detected after 1 and 2 days of exposure in the multifractal analysis, indicating a multifractal dimension of the vascular system and a relative dominance of small vessels in the yolk sac membrane.
The authors conclude that exposure of embryos of the Japanese quail (Coturnix japonica) to a 60 Hz magnetic field could inhibit the development of the vascular system in the yolk sac membrane and that lacunarity and multifractal dimensions analyses are appropriate and complementary methods for the measurement of this endpoint.

Study character:

Study funded by

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