Lama Sakhnini

Magnetic measurements on human erythrocytes: Normal, beta thalassemia major, and sickle

In this article magnetic measurements were made on human erythrocytes at different hemoglobin states (normal and reduced hemoglobin). Different blood samples: normal, beta thalassemia major, and sickle were studied. Beta thalassemia major and sickle samples were taken from patients receiving lifelong blood transfusion treatment. All samples examined exhibited diamagnetic behavior. Beta thalassemia major and sickle samples showed higher diamagnetic susceptibilities than that for the normal, which was attributed to the increase of membrane to hemoglobin volume ratio of the abnormal cells. Magnetic measurements showed that the erythrocytes in the reduced state showed less diamagnetic response in comparison with erythrocytes in the normal state. Analysis of the paramagnetic component of magnetization curves gave an effective magnetic moment of μeff=7.6 μB per reduced hemoglobin molecule. The same procedure was applied to sickle and beta thalassemia major samples and values for μeff were found to be comparable...

Subacute exposure to 50-Hz electromagnetic fields affect prenatal and neonatal mice’s motor coordination

In this study, we investigate the possible effect of ELF-EMFs on motor performance in mice (prenatal and neonatal exposed mice). The mice performance is evaluated after 5 days of subacute exposure. Immature mice have been chosen for this study because the immature rodent brain still has the capacity to undergo proliferation, differentiation, and reorganization. Results from the rotarod experiments demonstrated a pronounced deficit in the learning abilities of the prenatal exposed groups, but no pronounced effect was observed for the neonatal exposed group.

Effects of exposure to 50 Hz electromagnetic fields on Morris water-maze performance of prenatal and neonatal mice

Abstract Extremely low-frequency magnetic fields (ELF-MF), such as those originating from residential and occupational power lines, household appliances and medical devices, have been reported repeatedly to produce a variety of biological effects, which may induce a number of changes in behavioral differences of different living species, like insects and rodents. The purpose of the present study is to investigate the possible effect of an extremely low-frequency magnetic field ELF-MF (50 Hz, 1 mT) on spatial learning and memory functions in mice (prenatal and neonatal exposed mice) following a continuous 7-day exposure, using Morris water-maze. Immature mice have been chosen for this study since; the immature rodent brain still has the capacity to undergo proliferation, differentiation and re-organization and more closely resembles the developing brain of a human child. Thus, the immature rodent brain may provide a sensitive and useful animal model to study the possible biological effects of ELF-MF. Our results provide convincing evidence that long time MF exposure to immature mice; causes appreciable long term deficit in learning abilities.

Autism-relevant social abnormalities in mice exposed perinatally to extremely low frequency electromagnetic fields.

The incidence of autism spectrum disorders (ASD) has been rising, but the causes of ASD remain largely unidentified. Collective data have implicated the increased human exposure to electromagnetic fields (EMF) in the increasing incidence of ASD. There are established biological effects of extremely low‐frequency (ELF) EMF, but the relation to ASD is not investigated enough. In this study we examined the effects of perinatal exposure to ELF EMF on some ASD‐relevant behavioral parameters in mice. The EMF was delivered via a Helmholtz coil pair. Male BALB/C mice were used and divided into exposed and control groups (n = 8 and n = 9, respectively). Tests were used to assess sociability, preference for social novelty, locomotion, anxiety, exploratory behavior, motor coordination, and olfaction. The examined mice were all males and exposed to EMF during the last week of gestation and for 7 days after delivery. The exposed mice demonstrated a lack of normal sociability and preference for social novelty while maintaining normal anxiety‐like behavior, locomotion, motor coordination, and olfaction. Exposed mice also demonstrated decreased exploratory activity. We concluded that these results are supportive of the hypothesis of a causal link between exposure to ELF–EMF and ASD; however, replications of the study with further tests are recommended.

Effects of static magnetic fields on early embryonic development of the sea urchin echinometra mathaei

The influence of static magnetic fields with intensity of 30-50 mT on the early cleavage division of the sea urchin Echinometra 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.

Magneto-optical characteristics of human sperms: normal and deformed

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.

Detection of alterations in human sperm using magnetic orientation techniques

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/T2. 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.

Determining mechanical properties of rabbit skin with light reflection technique verified with latex

An experimental technique to evaluate the elastic limit for rabbit skin is developed and described. The experimental technique is designed to measure small changes in the normalized reflectivity as a function of applied stretch, with a laser wavelength of 632.8 nm and power of 1 mW. When the samples of rabbit skin are stretched, the reflectivity increases until a critical point (elastic limit) is reached. After this point, the curve drops off very quickly. The elastic limit for the male dorsal samples is less than that for the female samples, with an average strain of 14.4 and 34.6% in males and females, respectively. Moreover, our results show that the average slope of the regression lines is greater for the male dorsal samples than the dorsal female samples. This indicates that the male dorsal skin is rougher than that of the female.

Transfusion regimen in beta thalassemia major using magnetic measurement techniques

The magnetic behaviour of erythrocytes from patients suffering from beta thalassemia major was investigated. All samples exhibited diamagnetic behaviour. Measurements were made before and after blood transfusion treatment. We suggest that the amount of blood given to the patient should be controlled in a way that the diamagnetic susceptibility after blood transfusion should be equal to that for the normal erythrocytes. In this way a specific range of haemoglobin level (Hgb) should be maintained when the patient is subjected to long-term hypertransfusional treatment.