ABSTRACT
Objective To study the effects of bone marrow mesenchymal stem cells modified by brain-derived neuro-trophic factor ( BDNF) gene on the repair of spinal cord injury by electrophysiological assay .Methods Thirty healthy Spra-gue-Dawley rats (male and female) were randomly divided into 3 groups:Blank group, 10 rats (removal of the lamina only and exposed spinal dura mater );spinal cord injury (SCI) group,10 rats;and cell transplantation after SCI group , 10 rats. Eight rats of them were selected randomly and detected their SEP and MEP , and evaluated the degree of recovery of motor scores in the rats at 1 d, 7 d, 14 d, 21 d, 30 d, and 60 d.Result Since 4 days after cell transplantation , the process of hind limbs changes was as follows:at the 1-4 days after injury , the injury side hind limb had flaccid paralysis , mopping the floor walk, the movement of contralateral hind limb was gradually recovered from the initial injury , the injury side hind limb had spastic paralysis in 5-9 days after SCI;during 10-14 days, the injury side had a few activities;the contralateral side re-covered to a less normal state;At 15-21 days, activities of the injury side improved obviously , until the 30th day.The activ-ity and muscle tension degree of the injury side recovered most obviously .After 30 days no more obvious improvement was ob-served.Immunohistochemistry showed that the transplanted mesenchymal stem cells , which were induced and labeled firstly , survived at the damage spinal cord , and behavioral observation found that the cell transplantation improved exercise capacity of the rats injured before .Conclusion Bone marrow mesenchymal stem cells modified by BDNF gene can partially promote the recovery of nerve transmission function and nerve regeneration .
ABSTRACT
Objective To evaluate the effects of static magnetic fields (SMFs) of different intensity and exposure duration on the proliferation and apoptosis of human umbilical cord endothelial cells (HUVECs),and their release of nitric oxide (NO),6-keto-prostacyclin 1α (6-keto-PGF1α) and endothelin (ET-1).Methods Cultured HUVECs were exposed to a SMF at 5,22,86 or 135 mT for 8,12 or 24 hours.Their proliferation and apoptosis were monitored by flow cytometry (FCM).The medium was collected to test its NO content by optical density.ET-1 and 6-keto-PGF1α were measured by radioimmunization.Results ( 1 ) The proliferation of HUVECs increased when the cells were exposed to a SMF at 5 mT for 8 h,but a SMF at 135 mT for 12 h or 24 h inhibited the proliferation of HUVECs.(2)An SMF had no effect on apoptosis of HUVECs.(3)An SMF at 5 mT for 8 h increased the release of NO and 6-keto-PGF1 a,but the release of NO and 6-keto-PGF1 a decreased when the SMF intensity was 135 mT or the cells were exposed to an SMF for 12 h or 24 h.(4) An SMF at 5 mT or 22 mT for 8 h did not effect the release of ET-1.An SMF at 86 mT or 135 mT increased the release of ET-1.Compared with a control group,an SMF at 5 mT for 12 or 24 h did not affect the release of ET1,but at 22,80 or 135 mT,the release of ET-1 decreased significantly.Conclusions Exposure to a low intensity SMF for a short duration could improve the proliferation of HUVECs and increase the release of vasoactive factors,but if HUVECs are exposed to a strong SMF or exposed for a long duration,the proliferation and the release of vasoactive factors is decreased.