[Effect of magnetic field with 100 microT density on rat bone resorption]

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. In this experimental research, 30 Sprague-Dawley male rats were divided into 3 groups. Test group animals, were exposed to magnetic field [100 micro T, 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. 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 28[th] and 42[nd] days compared to day 0. There was a decrement in serum PTH concentration and increment in serum calcitonin concentration during the exposure period. 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

Phenytoin and the reproductive system

In order to evaluate the effects of phenytoin on the reproductive system of rats in detail, 60 male rats were divided equally into 6 groups: 1-5 received 10 mg/kg/day phenytoin IP for 1,2,3,4 and 5 weeks, respectively. However, group 5 did not receive any phenytoin for the last 5th week. The control group [group 6] did not receive any treatment. The results revealed that phenytoin does not have any effect on body weight, weight of testes, seminal vesicle and prostate, serum testosterone and sperm count taken from left and right vas deferenses. However, the percentage of total motile sperm and sperm with full and sluggish motility decreased and the percentage of low motile sperm increased in all experimental groups. Nevertheless, phenytoin caused atrophy and hypoplasia in seminiferous tubules and not Leydig cells. These pathological changes were dose-dependent and more pronounced in the left testis. But phenytoin caused more changes in sperm count and motility of the right testis. This phenomenon was discussed in relation to the existence of asymmetrical control by the hypothalamus, and compensation of the left testis. In summary, it could be concluded that phenytoin affected the seminiferous tubules directly and decreased the total number of motile sperm. It was also discussed that these effects are not reversible after termination of injection

Low intensity pulsed ultrasound treatment increases rabbit radial fracture healing

In order to study the effect of ultrasound [US] on bone healing, a complete transverse fracture was made in the right radius of adult male rabbits by a cutter. 52 rabbits were used: group 1, control [n=17]; group 2, test [n=15]; group 3, intact [n=1] and group 4 [n=12] who were examined only for evaluation of the cutter effects in detail. 7 animals were operated with a Gigli saw. The test group received US treatment 0.5 W/cm [2], 1MHz, 2 msec on-8 msec off for 10 min/day, from the day after surgery until complete fusion was observed. Radiological studies indicated that mean healing duration and rate of healing was significantly more in the test group than in controls. Histological evaluation showed the presence of ossified callus at week 3 in the test group, but in controls fibrous callus was still seen at week 5 after surgery. Bone mineral analyses by stereoelectron microscope showed that the mineral component of the treated bone reverts to normal, similar to the composition of intact bone, and sooner than that of the control. However, our results revealed no deleterious effects of US on treated and untreated ipsilateral and contralateral bones during the experiment or one month after complete fusion of the bones, at which time US was terminated