The influence of static magnetic fields with intensity of 30-50 mT on the early cleavage division of the sea urchinEchinometra mathaei was investigated. The exposure of fertilized eggs to 30, 40, and 50 mT of magnetic fields delayed the onset of early cleavage division. A delay in the first cleavage of 15, 30, and more than 60 min was caused by application of 30, 40, and 50 mT, respectively. The data also showed a significant decrease in cleaved cells for the exposed embryos. Moreover, the exposed eggs to magnetic fields showed more abnormalities compared to the control group. As the intensity of the magnetic field is increased, earlier appearances of abnormalities were observed. That is, deformed fertilization membrane appeared after only 15 min of exposure to 50 mT compared to 30 min in 30 and 40 mT exposures and 90-105 min in the control group.Index Terms-Embryonic development, fertilization membrane, sea urchin, static magnetic field.
In this study we report on magnetic orientation of human sperms. Samples were taken from 17 donors. Normal human sperms became oriented with their long axis perpendicular to the magnetic field (1 T maximum). Total orientation was achieved with magnetic field of about 1 T, while for abnormal sperms the magnetic behavior was different. The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result of a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of normal sperm was found to be Delta(chi) = 8 x 10(-20) J/T(2). The degree of orientation was influenced by the alterations in the shape of the head, body or the tail. It has been suggested that the DNA in the sperm head retain the strong magnetic anisotropy to counterbalance the magnetic anisotropy retained by flagellum microtubules. Recent studies demonstrated a well-defined nuclear architecture in human sperm nucleus, where the head morphology has significant correlation with sperm chromatin structure assay SCSA. Then, as the methods to evaluate SCSA can be difficult and expensive our simple magnetic orientation technique can be an alternative to diagnose alteration in DNA.
In this study we report on magnetic orientation of human sperms. Samples were taken from 17 donors. Normal human sperms became oriented with their long axis perpendicular to the magnetic field ( 1 Tesla maximum). Total orientation was achieved with magnetic field at about one Tesla, while for abnormal sperms the magnetic behavior was different. The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result for a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of normal sperm was found to be ∆χ= 8 ×10 -20 J/T 2 . The degree of orientation was influenced by the alterations in the shape of the head, body or the tail. It has been suggested that the DNA in the sperm head retain the strong magnetic anisotropy to counter balance the magnetic anisotropy retained by flagellum microtubules. Recent studies demonstrated a well-defined nuclear architecture in human sperm nucleus, where the head morphology has significant correlation with sperm chromatin structure assay SCSA. Then as the methods to evaluate SCSA can be difficult and expensive our simple magnetic orientation technique can be an alternative to diagnose alteration in DNA.
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