[Effects of extremely low frequency electromagnetic field on mouse liver histology]

Despite widespread use of electromagnetic field [EMF] generator devices in everyday life, their effects on biological tissues are still controversial. In the present study, the effects of EMF on the mouse liver were studied. Thirty female balb/c mice were randomly divided into three groups: 1- EMF-exposed, 2-Sham, and 3-Control. EMF group was exposed to 50 Hz and 0.5 mT EMF 4 hours daily for 2 months while the animals in sham group were placed in EMF device without exposure. At the end of 2-month period, all animals were anesthetized and their livers were removed. After preparation of microscopic slides, the panoramic view of liver, the number of Kupffer and necrotic cells were determined using 'Image Tool' software. The data were statistically analyzed using ANOVA and Dunnett's tests. p<0.05 was considered as statically significant. The comparison of data showed that the mean number of Kupffer cells in EMF group significantly increased compared to sham and control group [p<0.001 for both], while the mean number of Kupffer cells in sham group showed no significant difference compared to control group. The mean number of necrotic cells in experimental groups had no significant increase compared to sham and control groups. There were no significant differences in the mean number of necrotic cells between sham and control groups. Qualitative studies also showed no disorganization in the structure of liver lobules and sinusoids in the exposed group compared to sham and control groups. According to the results of this study, longtime exposure to electromagnetic field could increase Kupffer cells but do not affect the necrosis of liver cells in mice

[Comparative study on xnograft saffold and prous hydroxyapatite/tricalcium phosphate for the repair of bony defect]

The aim of this study was to compare xenograft scaffold and prous Hydroxyapatite/Tricalcium phosphate for the repair of bony defect. 5 New Zealand rabbits with the average weight of 2 kg were used. The rabbits were anesthetized with ketamine 60 mg/kg and xylazin 6 mg/kg After creating a critical-sized segmental defect [2x3 cm] in tibia bones, an implant of HA/TCP with osteoblasts in the hole of left tibia and an implant of xenograft with osteoblasts in the hole of right tibia was inserted. At the end of the second month, the animals were sacrificed. To follow up the new bone formation, x-ray images were taken at 8[th] week post-operation. To confirm the tissue repairment, the histology of repaired defects was evaluated with H and E staining after decalcification. The present study demonstrates that the critical-size segmental defect of tibia can be repaired with both synthetic HA/TCP and xenograft implants. xenograft implants showed better osteointegration compared to HA/TCP phosphate

[ effects of crowding stress on cortex of mousecerebellum]

Nowadays, the remarkable growth of population and its subsequent overcrowding in big cities maybe an important factor in causing neural system sensivity against environmental agents.Taking this issue into account, the present study aimed at investigating the effects of social stress on cortex of mouse cerebellum. 60 adult male mice of the NMRI strain were selected at the age of 5-6 weeks and were randomly divided into 6 groups. In the first three groups, 5 animals per cage [as control], 10 animals per cage [mild stress condition] and 15 animals per cage [sever stress condition] were housed for one month and the next three groups with same condition in same manner were housed for two months [groups 4, 5 and 6]. All animals were anesthetized and weighed. The samples of right lobe of cerebellum were removed and fixed for light microscopic study. The thickness of the molecular and granular layers and the number and height of purkinje cells were analyzed by Image Tool soft ware. The results showed that the mean weight of animals in group 3 and group 6[sever stress condition] were significantly reduced compared to the control group [p<0.001], while the mean weight of animals in mild stress conditions was not significantly reduced compared to controls. The mean number of purkinje cells between groups 2 and 6 showed a significant difference [p<0.004]. The mean height of purkinje cells in all stress groups [group 2, 3, 5 and 6] was significantly reduced compared to group 1 [p<0.001]. The thickness of the molecular and granular layers in all stress groups showed insignificant difference compared to the control group. It can be concluded that the social stress has a detrimental effect on cortex of mouse cerebellum by decreasing the weights of animals, the number and height of cerebellar purkinje cells

[ effects of electromagnetic field on fertility and mouse gonads in preimplantation stage]

Considerable attention is focused on the effects of the electromagnetic field [EMF] due to its wide-ranging use in everyday life. Appliances and various equipments are sources of electromagnetic fields with a wide-range of technical characteristics. In this study we investigated the effect of EMF [50 Hz, 0.5 mT] on fertility and mouse gonads in preimplantation. Materials and Methods: Eighty female mice were divided in to 2 groups the control group was not exposed to EMF, while the case group was exposed to 4 hours per day, to 50 Hz and 0.5 mT EMF 6 days a week, for 2 weeks. On the 8th day of exposure, female mice in both groups were superovoulated and mated overnight. Next morning females with a vaginal plug were identified as pregnant mice at the time of implantation, the pregnant mice were sacrificed and blastocysts were subsequently obtained from these mice by flushing the uterus horns. The samples of ovaries in all groups were taken and were processed for light microscopic studies, and the data was compared using t-test [SPSS, considering, and P < 0.05], significant. Results: The mean number of pregnant mice decreased in the EMF group [50%] as compared to the control group [67.5%], difference not significant. The mean number of fetuses per pregnancy was 9 +/- 4.8 in the control group and 5.5 +/- 5.7 in the experimental group, with significant decrease between the means of the 2 groups [P < 0.03]. The analysis of the size of monolayer primary follicle in the EMF exposed groups did not show significant decrease compared to the control group [12.33 +/- 1.53, 12.17 +/- 1.79 and P>0.810]. Although the total number of follicles, number of monolayer primary follicles and corpus luteum, increased in comparison to control group following there was no significant differences between them. Conclusion: The findings indicated that the EMF, following short periods of exposure, has negative effects on female mice fertility, whereas histological studies showed no changes in ovaries

[ effects of prenatal morphine exposure on spatial learning]

Drug abuse during pregnancy is a growing problem in all developed countries worldwide. Maternal drug abuse affects the developing systems and the associated long-term effects can persist untill adulthood, decreasing the rate of their maturation. To determine the effects of prenatal morphine exposure on spatial learning Eighteen pregnant rats were divided into morphine, saline, and control groups. Morphine or saline was administrated [S.C] to female rats twice a day [at 12-hr intervals] during the days 11-18 of their gestational period [5 mg/kg morphine for the first 3 days and 10 mg/kg for further 5 days]. Pups [P90, n=6] were trained in an 8-arm radial maze apparatus.The data were analyzed statistically using Chi-square test. The results indicated that prenatal morphine exposure causes a reduction in the time needed to learn these trials however, they needed more time to complete regular trials. Prenatal morphine exposure impairs normal spatial learning

[ ultrastructural effects of superovulatory drugs on mouse endometrial basement membrane]

The endometrial basement membrane has a major role in implantation of embryo. Studies have recently shown that the rate of successful implantation in stimulatory cycles is less than in normal cycle due to detrimental effect of superovulatory drugs on endometrium. To investigate the effect of stimulatory drugs on ultrastrucures of mouse endometrial basement membrane. The endometrial samples were obtained form 30 naturally pregnant mice [control group] and 30 syperovulated mice [experimental group] at the time of implantation [120 h after hCG injection]. Induced with PMSG [10 IU] and hCG [10 IU]. The specimens were processed for electron microscopic studies. Qualitative [based on electron density] and quantitative [thickness of basement membrane] studies were performed on micrographs. The data were analyzed using Mann-Whitney statistical test]. The qualitative observation of the case group revealed a well developed RER, increased number of mitochondria and high electron density of basement membrane. The quantitative data demonstrated that the thickness of basement membrane and lamina densa were significantly increased in the case group compared with control group [0.283 +/- 0.0777, 0.158 +/- 0.00827 vs. 0.239 +/- 0.0082, 0.155 +/- 0.0111, P< 0.05]. It can be concluded that superovulation drugs may lead to low implantation rate by changing the endometrial basement membrane

influences of cryoprotectants on viability of embryos produced in vitro

The post-thaw embryo survival has been shown to depend on different factors such as type of cryoprotectant. Ethylene glycol, 1,2 propanediol and glycerol are among the routine cryoprotectants widely used for embryo cryopreservation in different animals and human as well. To investigate the effects of different cryoprotectants on viability of blastocysts produced in vitro and also determining a suitable cryoprotectant for embryo cryopreservation. A total of 197 porcine blastocysts produced in vitro [at days 6 and 7 post-IVF] were randomly divided into control and cryoprotectant [CP] groups. The CP groups were exposed to 10% CP solutions [Ethylene glycol, 1,2 propanediol and glycerol] in 3 steps for 1 hr at room temperature [23-25°C]. The survival rate was measured as the proportion of recovered embryos following a 24-hr culture in NCSU-37 media. The survival rate was further compared with the data obtained from the control group [cultured in 0.3% BSA in PBS with the same conditions]. The results showed that the survival rates of blastocysts exposed to PD and GLY were similar to those exposed to EG [p<0.05]. However, there was no significant difference [P>0.05] in survival rates between the EG and control groups. The data indicated that the exposure of porcine blastocysts to cryoprotectant causes a reduction in survival rate and that the ethylene glycol produced the least detrimental effects

[Effect of vitrification on apoptosis in mouse blastocysts]

In recent years there have been a great advances in vitrification of embryos. However, there is no reliable vitrification protocol to ensure a high embryo survival rate, Because the mechanisms of embryo injury has not been discovered precisely. The aim of the present study was to determine the effects of vitrification on apoptosis in mouse blastocysts. Ninety five mouse blastocysts were obtained by flushing from Swiss Albino mouse and randomly divided into control and experimental groups. Blastocysts in the control group [52] were cultured in Ml6 media for 2 hours and then the apoptotic index were obtained after staining by TUNEL technique with PI. Blastocysts in the experimental group [43] were vitrified just after flushing in EFS40 solution and kept in LN2 for one month. After thawing and culture in M16 for 2 hours, the apoptotic indices were obtained by TUNEL staining. The results showed that the mean number of blastomers in the vitrified blastocysts group [44.91 +/- 2.47] was not significantly different [P=0.176] from those that seen in the control group [50.23 +/- 2.9], while the mean number of apoptotic blastomers in vitrified blastocysts group [4.08 +/- 0.28] was significantly higher [P=0.02] as compared to the control group [4.93 +/- 0.22]. The mean apoptosis Index in vitrified blastocysts [11.87 +/- 0.63] was significantly higher [P<0.004] than the control group [9.12 +/- 0.67]. We can conclude that the vitrification can increase apoptotic cell death in mouse blastocysts