Razi Journal of Medical Sciences

    The increasing presence of low intensity uniform magnetic fields in different environments such as factories, industries, hospitals, in transport and electrical devices and medical application has become so important. Therefore, conducting an investigation on the effects of magnetic fields on properties and revenues of human body’s different tissues, especially nerve tissue, seems necessary from protection and medical application viewpoint. In this respect, the present study was undertaken to investigate the effect of low intensity uniform magnetic fields on nerve signals’ electrical conduction velocity. In this study, 0.5mT magnetic field was exposed on neuromuscular junction of abductor polices brevies muscle and median peripheral motor nerve. The latency and nerve electrical conduction velocity in left wrist of 30 healthy men, before and after exposure to the magnetic field was measured by stimulating and recording device (Cadwell 5200 A). The results indicated that magnetic field causes decrease in nerve signals electrical conduction velocity due to increase of neuromuscular neurotransmitters revenues, latency or increase of muscular fibers signal transmission latency (P<0.05). Increase in latency and decrease of electrical conduction velocity in neuromuscular junction may be due to the Lorants force effect of magnetic field on neuro transmitters (such as acetylcholine) or increasing neuromuscular space distance. Also, the increase of muscle fibers signals transmission latency may be due to Ca²⁺ concentration or fibers excitability level changes.

     Background & Aim: In human environment, magnetic fields are created by electrical generators, power lines, and electrical instruments. These fields could affect learning and memory. This study was planned to evaluate whether short time exposure to magnetic fields has any significant effect on spatial memory. Material & Method: In this experimental study, we used 10 male Albino Wistar mice that were trained for spatial memory in a T-maze model within six days. Twenty-four hours after training, animals were tested for retention of discrimination in three stages(control, restrainer and magnetic field) at two-hour intervals and each of the animals was given 5 successive trials at one-minute intervals. The time of movement from the start area until they reached the criterion zone was measured by a chronometer. Magnetic field was induced by a round coil with an internal diameter of 8 cm and 850 turns of copper wire. Maximum intensity of 7.5 mT at the center of the coil was calibrated by a digital teslameter. Results: Evaluation of the results of the three stages indicated that the mean of time was 15.4 s, 11.5 s, 11.3 s respectively. Also, there was a significant difference between the time in the control stage and the other stages (P<0.05), but there was no significant difference between the restrainer stage and the magnetic field regarding the time measured. Conclusion: Research findings indicated that short time 7.5 mT, 50 Hz magnetic field did not have any significant effect on T-maze alternation tasks in mice and it would probably have no effect on spatial memory process either.

Background: In the recent decades, there has been an increasing effort to study possible biological effects of extremely low frequency electromagnetic fields (ELF-EMFs). In this study, the effects of 50 Hz, 0.6 mT pulsed electromagnetic field on proliferation and biochemical properties, in a prostate cancer cell line, DU-145, and the simultaneous treatment of these cells with electromagnetic field and anticancer drug, berberine, were explored

Methods: Control and treated cells were seeded in separate plate dishes and cell proliferation, concentration of reactive oxygen species (ROS), survivin expression and DNA damage were studied by MTT assay, Fluorescence spectrometry, Western blotting and Comet assay, respectively.

Results: Our results showed a significant increment in cell proliferation and intracellular concentration of ROS after 24-72 hours of continuous exposure to the field. The treatment did not affect the expression level of the cancer biomarker, survivin, but acted as a genotoxic agent and increased DNA single and double strand damages. The results also showed that continuous exposure to the applied field does not have any effect on the cytotoxic activity of berberine in DU-145 cells.

Conclusion: On the whole, it seems that the studied electromagnetic field acts as a tumor promoter in this cell line, possibly through induction of oxidative stress and DNA damage.

Background: Ischemic stroke is a common cause of adult disability and death worldwide that leads to damage in neuronal networks and neurovascular units and ceasation of brain functions. In this study the effect of iron oxide nanoparticles and magnetic field on neurogenesis after ischemic reperfusion (IR) in rat model was evaluated.
Methods: In this experimental study 50 male Wistar rats weighing 220-250 g were randomly divided into five groups of 10 rats each: including control, sham (ischemic reperfusion model), IR + iron oxide nanoparticles (10mg/kg), IR+magnetic field (1 Tesla, 20 min in 4 days), and IR + iron oxide nanoparticles and magnetic field groups. Injections were performed intraperitoneally. Neurogenesis was evaluated in hippocampus of 5 groups after 4 days by H&E staining method. Nestin gene expression was quantitatively investigated in 5 groups by Real-time PCR.
Results: In this study it was revealed that the iron oxide nanoparticles as well as the magnetic field increase the neurogenesis rate after ischemic reperfusion during 4 days (p<0.05). The expression of Nestin gene increased in iron oxide nanoparticles treated group and the magnetic field exposed group significantly (p<0.05) as compared to ischemic reperfusion model. However, their combined treatment did not show a significant difference compared with the sham group within 4 days.
Conclusion: Our result suggests iron oxide nanoparticles as well as magnetic field separately can be two effective methods in ischemia therapy.