ABSTRACT
BACKGROUND: Many studies showed that neural stem cells (NSC) transplantation can promote functional improvements in rats subjected to spinal cord injury. However, the underlying molecular mechanisms remain poorly understood.OBJECTIVE: To observe the effects of NSC transplantation on expressions of Bax, Bcl-2 and Caspase-3 in the motor cortex in rats subjected to spinal cord transection.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at Institute of Neuroscience,Kunming Medical College from July 2007 to December 2008.MATERIALS: Five green fluorescent protein transgenic mice with 14-15 embryonic days were prepared for NSC. Additionally 88 adult female Sprague-Dawley (SD) rats were randomly divided into sham operation group (n=8), model group (n=40) and NSC transplantation group (n=40).METHODS: Model of spinal cord transection was established by cut transversely Sprague-Dawley (SD) rats T_9 segment. Rats in the sham operation group were subjected to laminectomy at T_8, without spinal cord injury. After the spinal cord was exposed at the lesion site, a small piece of 2 mm~3 gel foam soaked with 3×10~5 NSC were implanted into the gap to fill the lesion site of the T_9 level in rats of the NSC transplantation group. The measurements of relative indexes were performed at the days 3, 7,14, 21 and 28 after transplantation.MAIN OUTCOME MEASURES: Changes of Bax, Bcl-2 and Caspase-3 expressions were detected by RT-PCR.RESULTS: Compared to the sham operation group, the Bax expression in the model group had no significant difference (P >0.05), the expression of Bcl-2 was decreased obviously at days 14 and 28 after operation (P < 0.05), while a significant increase on the expression of Caspase-3 at day 3 (P < 0.05). Compared to the model group, the expression of Bax was dramatically decreased in the NSC transplantation group at day 3 (P < 0.05), with a notably increased Bcl-2 expression at days 14 and 21 after transplantation (P < 0.05), but the expression of Caspase-3 presented a significant decrease at days 3 and 7 after transplantation (P < 0.05).CONCLUSION: NSC transplantation probably regulates the expression of apoptosis genes (Bax, Bcl-2 and Caspase-3 mRNA) to promote neurological function recovery in rats subjected to cord transection.
ABSTRACT
Through the analysis about the present situation of the bilingual education in our college,we have expounded the necessity and urgency of bilingual education,proposed several suggestions about incentive methods of bilingual education and advanced training,and explore the mode of primary bilingual education.