title: Multifractal dimension and lacunarity of yolk sac vasculature after exposure to magnetic field.
abstract: Several studies have reported about the effects of magnetic fields (MFs) on vascular tissue. Extremely low frequency magnetic fields (ELF-MFs) can promote either inhibition or stimulation of vasculogenesis and angiogenesis, depending upon the intensity and time of exposure to the MF. To investigate the possible effects of ELF-MF on vascular processes, it is necessary to employ methods that allow parameterization of the vascular network. Vascular network is a structure with fractal geometry; therefore, fractal methods have been used to evaluate its morphometric complexity. Here, we used the lacunarity parameter (complementary method of fractal analysis) and multifractal analyses to investigate angiogenesis and vasculogenesis in the embryonic yolk sac membrane (YSM) of Japanese quails (Coturnix japonica) with and without exposure to an external MF of 1 mT and 60 Hz. Lacunarity results showed that the vascular density was lower for the group exposed to the magnetic field for 9 h/day. In addition, multifractal analysis showed reduced vascularization in the experimental groups (6 h/day and 9 h/day of exposure to MF). Furthermore, multifractal analysis showed difference between the groups exposed for 12 and 24 h/day. Using multifractal methods (generalized dimensions and singularity spectrum), it was possible to characterize the vascular network of the quail embryo YSM as a multifractal object, therefore proving this method to be a more appropriate application than the traditional monofractal methods.
authors.affiliation: Department of Animal Morphology and Physiology, Rural Federal University of Pernambuco, Recife, Brazil; Laboratory of Theoretical, Experimental and Computational Biophysics, Rural Federal University of Pernambuco, Recife, Brazil.
authors.forename: Edbhergue Ventura Lola
authors.initials: EV
authors.lastname: Costa
authors.affiliation: Department of Animal Morphology and Physiology, Rural Federal University of Pernambuco, Recife, Brazil; Laboratory of Theoretical, Experimental and Computational Biophysics, Rural Federal University of Pernambuco, Recife, Brazil. Electronic address: ran.pe@terra.com.br.
authors.forename: Romildo de Albuquerque
authors.initials: Rde A
authors.lastname: Nogueira
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000196:embryology*; D003370:Coturnix / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000098:blood supply / Q000528:radiation effects; D017709:Fractals; D060526:Magnetic Fields; D015233:Models, Statistical; D009389:Neovascularization, Pathologic; D011336:Probability; D011840:Radiation, Nonionizing; D013997:Time Factors; D015017:Yolk Sac / Q000098:blood supply* / Q000528:radiation effects
keywords: Angiogenesis; Lacunarity parameter; Magnetic field; Multifractal analysis; Vasculogenesis; Yolk sac membrane