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Background&Objective: Electromagnetic fields are present everywhere in our environment with various intensities, so, investigation about their effects on living organism is very important. The aim of this experiment study to investigate the effect of magnetic field on bone resorption, PTH and calcitonin concentration and their correlations. Materials&Methods: In this experimental research, 30 Sprague-Dawley male rats were divided into 3 groups. Test group animals, were exposed to magnetic field (100µT, 50 Hz), 4 hours per day for a period of 42 days. Experimental condition for control-1 group was the same as test group, except that, they were not exposed. Animals of control-2 group were killed at the first day of experiment (day 0). Total left femoral bone calcium and phosphorus content and its fracture energy was measured at days 28 and 42 in control-1 and test group and on day 0 in control-2 group. However, serum calcium, phosphorus, PTH and calcitonin concentration were measured on day 0, the first day of exposure, and thereafter once per two weeks. Results: Total bone calcium content in test group was significantly lower than control-1 and 2 groups, and bone fracture energy showed a slightly decrease. On the other hand, serum calcium and phosphorus concentration increased significantly on 28th and 42nd days compared to day 0. There was a decrement in serum PTH concentration and increment in serum calcitonin concentration during the exposure period. Conclusion: Our results suggested that magnetic field could have a direct effect on bone resorption, and observed changes in PTH and calcitonin were in good correlation with serum calcium and phosphorus concentrations (negative feed back) and these changes also prevent further increase in bone resorption.

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Background & Objective: Monitoring the depth of anesthesia is very important to prevent undesirable events during surgery, such as intra operative awareness and overdosing. It is shown that anesthetic agents have direct effects on synaptic activity of brain neurons. So there is a great interest on electroencephalogram analysis as a depth of anesthesia estimator. Due to difficulties in visual explanation of EEG, automatic and computer based signal processing methods have been used to assess the depth of anesthesia. Investigating the relationship between conscious level of patients and electrical activity of brain neurons was the main aim of this study. Materials & Methods: In this study, EEG signals of six patients undergoing aortic valve replacement surgery have been acquired and recorded in a computer. After applying signal processing methods to these data, 3 different measures included temporal, spectral and bispectral parameters have been extracted. Mean values of mentioned parameters in different anesthetic regimens and levels have been analyzed by ANOVA in SPSS software. Results: Extracted temporal parameter is correlated with depth of anesthesia in deep anesthetic levels and spectral one is correlated with depth of anesthesia in moderate and light levels (P<0.05). Bispectral parameter is correlated with the depth of anesthesia only in ICU (P<0.05). Conclusion: Findings of this study confirm the relationship between consciousness and electrical activity of brain neurons and recommend the use of EEG processing techniques to monitor, control and estimate the depth of anesthesia in operating room and ICU ward.