Effect of electromagnetic pulse exposure on brain micro vascular permeability in rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To observe the effect of electromagnetic pulse (EMP) exposure on cerebral micro vascular permeability in rats.</p><p><b>METHODS</b>The whole-body of male Sprague-Dawley rats were exposed or sham exposed to 200 pulses or 400 pulses (1 Hz) of EMP at 200 kV/m. At 0.5, 1, 3, 6, and 12 h after EMP exposure, the permeability of cerebral micro vascular was detected by transmission electron microscopy and immunohistochemistry using lanthanum nitrate and endogenous albumin as vascular tracers, respectively.</p><p><b>RESULTS</b>The lanthanum nitrate tracer was limited to the micro vascular lumen with no lanthanum nitrate or albumin tracer extravasation in control rat brain. After EMP exposure, the lanthanum nitrate ions reached the tight junction, basal lamina and pericapillary tissue. Similarly, the albumin immunopositive staining was identified in pericapillary tissue. The changes in brain micro vascular permeability were transient, the leakage of micro vascular vessels appeared at 1 h, and reached its peak at 3 h, and nearly recovered at 12 h, after EMP exposure. In addition, the leakage of micro vascular was more obvious after exposure of EMP at 400 pulses than after exposure of EMP at 200 pulses.</p><p><b>CONCLUSION</b>Exposure to 200 and 400 pulses (1 Hz) of EMP at 200 kV/m can increase cerebral micro vascular permeability in rats, which is recoverable.</p>

Comparison of Hsps expression after radio-frequency field exposure in three human glioma cell lines / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate and compare the effect of radio-frequency (RF) field exposure on expression of heat shock proteins (Hsps) in three human glioma cell lines (MO54, A172, and T98).</p><p><b>METHODS</b>Cells were exposed to sham or 1950 MHz continuous-wave for 1 h. Specific absorption rates (SARs) were 1 and 10 W/kg. Localization and expression of Hsp27 and phosphorylated Hsp27 ((78) Ser) (p-Hsp27) were examined by immunocytochemistry. Expression levels of Hsp27, p-Hs27, and Hsp70 were determined by Western blotting.</p><p><b>RESULTS</b>The Hsp27 was primarily located within the cytoplasm, p-Hsp27 in both cytoplasm and nuclei of MO54, A172, and T98 cells. RF field exposure did not affect the distribution or expression of Hsp27. In addition, Western blotting showed no significant differences in protein expression of Hsp27 or Hsp70 between sham- and RF field-exposed cells at a SAR of 1 W/kg and 10 W/kg for 1 h in three cells lines. Exposure to RF field at a SAR of 10 W/kg for 1 h slightly decreased the protein level of phosphorylated Hsp27 in MO54 cells.</p><p><b>CONCLUSION</b>The 1950 MHz RF field has only little or no apparent effect on Hsp70 and Hsp27 expression in MO54, A172, and T98 cells.</p>

Effects of electromagnetic pulse on bone metabolism of mice in vivo / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the effects of electromagnetic pulse (EMP) on bone metabolism of mice in vivo.</p><p><b>METHODS</b>Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups (n=8). The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase (ALP) activity, serum calcium concentration and osteocalcin level and trabecular bone volume (BV/TV, %) were measured immediately after EMP exposure by biochemical, ELISA and morphological methods.</p><p><b>RESULTS</b>The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conclusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.</p>

Effects of electromagnetic pulse on blood-brain barrier permeability and tight junction proteins in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of electromagnetic pulse (EMP) on the permeability of blood-brain barrier, tight junction (TJ)-associated protein expression and localization in rats.</p><p><b>METHODS</b>66 male SD rats, weighing (200 approximately 250) g, were sham or whole-body exposed to EMP at 200 kV/m for 200 pulses. The repetition rate was 1 Hz. The permeability of the blood-brain barrier in rats was assessed by albumin immunohistochemistry. The expression of typical tight junction protein ZO-1 and occludin in both cerebral cortex homogenate and cerebral cortex microvessel homogenate was analyzed by the Western blotting and the distribution of ZO-1 and occludin was examined by immunofluorescence microscopy.</p><p><b>RESULTS</b>In the sham exposure rats, no brain capillaries showed albumin leakage, at 0.5 h after 200 kV/m EMP exposure for 200 pulses; a few brain capillaries with extravasated serum albumin was found, with the time extended, the number of brain capillaries with extravasated serum albumin increased, and reached the peak at 3 h, then began to recover at 6 h. In addition, no change in the distribution of the occludin was found after EMP exposure. Total occludin expression had no significant change compared with the control. However, the expression level of ZO-1 significantly decreased at 1 h and 3 h after EMP exposure in both cerebral cortex homogenate and cerebral cortex microvessel homogenate. Furthermore, immunofluorescence studies also showed alterations in ZO-1 protein localization in cerebral cortex microvessel.</p><p><b>CONCLUSION</b>The EMP exposure (200 kV/m, 200 pulses) could increase blood-brain barrier permeability in rat, and this change is associated with specific alterations in tight junction protein ZO-1.</p>