Electromagnetic Biology and Medicine最新文献

This study assessed subjective symptoms associated with exposure to static magnetic fields (SMFs) and radiofrequency (RF) energy, and perceived safety risk of scanners among magnetic resonance (MR) staff working in the 1.5 and 3 T MRI units. A questionnaire survey was completed by 77 clinical imaging staff working in two hospitals (A and B) in the Mangaung metropolitan region. 50 participants working with the MR scanners were regarded as exposed group and 27 participants from CT scan and X-ray departments were classified as control group. The study comprised 57% females and 43% male participants with an average MRI experience of 5.4 years. Using logistic regression, tinnitus was significantly different between various job titles (p< .034) and it was reported more often (OR 8:00; CI 1.51, 15.17) by those who worked on a 3 T scanner. Increased years of MRI experience was a significant predictor of headache (p< .05), and reporting of nausea was significantly different between various job titles (p < .01). There was an increased risks of reporting vertigo often among female participants (OR: 4.43; CI 0.91, 21.47), those with 5-15 years of MRI experience (OR: 2.09; CI 0.47, 9.34), and those with a light to moderate workload (OR: 2.70; CI 0.49, 14.86). Using linear regression, presence in zone IV during image acquisitioning was the only significant predictor for the sensation of glowing (p < .000). Movement of head/ upper body in the scanner bore was a significant predictor of nausea (p< .026), vertigo (p< .014), instability when standing (p< .014), and a metallic taste (p< .031). There was no correlation between reporting of symptoms and perceived risk of scanners. However, shift duration (r_s = 0.576), movement of head/upper body in the scanner bore (r_s = 0.424), and strength of the scanners (r_s = 0.299) were significantly correlated with perceived risk of scanners. MRI safety training and a comprehensive occupational health and safety program are necessary.

Doppler ultrasonography (DUSG) is widely used for fetal evaluations. This study investigated the effects of new generation Doppler ultrasound application at different frequencies during pregnancy on postnatal renal development. Six pregnant female rats were divided into three groups. No procedure was performed on the first (control) group. In the second group, transabdominal DUSG was performed continuously for 15 min every day from the first day of gestation until birth. In the third group, DUSG was applied for 15 min every two days. Twenty-four male pups were sacrificed after 60 days. Renal tissues were then collected and subjected to biochemical, histopathological, and immunohistochemical evaluation. Malondialdehyde, glutathione, urea, Ca, K, and Cl levels increased in the DUSG groups compared to the control group (p < .05). Histopathologically, tubular damage increased in the DUSG groups compared to the control group (p < .05). Immunohistochemically, an increase was determined in Caspase-3 expression in the DUSG groups compared to the control group (p > .05). The DUSG groups also exhibited an increase in the superficial areas of the proximal and distal tubules, although the difference compared to the control group was not significant (p > .05). Multiple administrations of new generation DUSG to pregnant rats resulted in deleterious effects on the development of postnatal renal tissue. This shows that DUSG should be applied for as short a time as possible and that re-exposure should be avoided.

The mechanism underlying the biological effects caused by an extremely low-frequency electromagnetic field (ELF-EMF) is still unclear. Previously, we found that L-type calcium channel and sphingosine kinase 1 (SK1) were involved in 50-Hz MF exposure-induced cell proliferation. In the present study, the role of intracellular Ca²⁺ and signal molecules related to SK1 in cell proliferation induced by 50-Hz MF was investigated in human amniotic epithelial (FL) cells. Results showed that the intracellular Ca²⁺ chelator, BAPTA, could completely inhibit 50-Hz MF-induced cell proliferation, whereas NIF, the inhibitor of L-type calcium channel, only partly blocked it. When cells were cultured in calcium-free medium, MF exposure also increased intracellular Ca²⁺, activated SK1 and promoted cell proliferation although all of those increasing levels were lower than those in complete medium. Moreover, MF-activated SK1 could be completely inhibited by BAPTA, and MF-induced cell proliferation was abolished by SKI II, the specific inhibitor of SK1. Additionally, a 50-Hz MF exposure did not affect the activation of ERK and PKCα under the condition of calcium-free medium, but activated the Akt, which could be precluded entirely by BAPTA, but not be inhibited by NIF. Treatment of FL cells with LY294002, the inhibitor of Akt, could delete the MF-induced SK1 activation under the condition of calcium-free medium. Based on the data from the present experiment, it is concluded that endogenous Ca²⁺ release was involved in 50-Hz MF-induced cell proliferation via Akt-SK1 signal cascade.

In this study, the motion and deformation of a red blood cell in a Poiseuille flow through microvessels under the effect of a uniform transverse magnetic field is comprehensively investigated to get a better insight into blood hemorheology. The rheology of the RBC and the surrounding blood flow are examined numerically in two dimensions using a Finite Element Method. It is essential to know that the flow patterns of blood change in the presence of an RBC. The simulation results demonstrate that the magnetic field has significant influence on the flow stream and the behavior of the RBC, including the motion and the cells deformation.