Objective To explore the differences of cultivation and differentiation between cortical neural stem cells(C-NSCs) and mesencephalic neural stem cells(M-NSCs). Methods We dissociated embryonic cortex and ventral mesencephalon respectively,and single cell suspensions were achieved by trypsin digestion and mechanical dissociation in sterile condition.These cells were planted into DMEM/F12 culture medium with B27,bFCF,and then were passaged by mechanical methods and induced to differentiation in DMEM/F12 medium with 10%FBS(without growth factors).For examining the features of C-NSCs and M-NSCs,reverse phasecontrast microscopy,immunocytochemical techniques were applied to detect nestin,NSE,GFAP antigens and the specific antigen(TH) of neurons differentiated from the two kinds of NSCs.We observed and compared the difference of the two kinds of NSCs. Results The NSCs existed both in cortex and ventral mesencephalon of embryonic mice,which expressed nestin and possessed the ability of self-renewing and multipotent, but the density of NSCs in cortex was higher than that in ventral mesencephalon.There were some TH positive cells differentiated from M-NSCs but none came from C-NSCs.Conclusion The proliferative activity of C-NSCs is higher than that of M-NSCs,but more number M-NSCs differentiated into dopaminergic neurons in serum medium.

Objective To study whether mechanical noise acting on the sacculus could enhance the SNR of the 8th nerve’s response.Methods Driving PZT by adding white noise of various level to periodic signals(f=100 Hz),the directly mechanical stimuli was give to the five sacculus submerged in a solution containing perilymph-like, and the afferent activity the 8th nerve was recorded.Results The SNR of the nerve signal was improved by addition nanometer-level noise to the periodic stimuli in all responsive animal(4.1 dB, on average).It was found that 2.3 nm of mechanical noise enhanced the response of the saccular nerve.Conclusion The addition of a few nanometers of noise to a periodic stimuli leads to a substantial improvement in the SNR of the nerve’s response.

BACKGROUND:Spinal posterior surgery is the most common treatment method for thoracolumbar fracture. During exposure of conventional posterior surgery, a wide-range stripping and pul ing of paraspinal muscles easily induced failure syndrome of lumbar surgery.
OBJECTIVE:To compare the reset conditions and stability of thoracolumbar fractures after treatment with pedicle screw paraspinal muscle approach and conventional posterior median approach fixation.
METHODA total of 62 patients with thoracolumbar fractures without nerve injury were retrospectively analyzed. 22 patients were treated with paraspinal muscle approach and general spine system. 21 patients were treated with conventional median approach and general spine system. 19 patients were treated with conventional median approach and AF internal fixation system. The therapeutic effects of the three kinds of fixation methods were compared by comparing clinical indexes in patients of the three groups, including operation time, intraoperative blood loss, postoperative drainage, dead space volume, scores of the Visual Analogue Scale of back pain, wound complications, height of injured vertebrae and the Cobb angle.
RESULTS AND CONCLUSION:Operation time, intraoperative blood loss, postoperative drainage and dead space volume were better in the paraspinal muscle approach and general spine system group than in the conventional median approach and general spine system group and conventional median approach and AF internal fixation system group (P<0.05). No significant difference in height of injured vertebrae and the Cobb angle was detectable among the three groups at 3 days after fixation (P>0.05). No significant difference in scores of the Visual Analogue Scale of back pain was visible among the three groups at 1 week after fixation (P>0.05). The scores of the Visual Analogue Scale of back pain were apparently lower in the paraspinal muscle approach and general spine system group than in the conventional median approach and general spine system group and conventional median approach and AF internal fixation system group at 3 and 6 months after fixation. No incision infection was observed in patients of the three groups. These results suggested that compared with conventional posterior median approach, paraspinal muscle approach has some advantages, such as smal trauma, less bleeding, postoperative rapid recovery, and high degree of satisfaction. The effects of general spine system and AF internal fixation system in the repair of thoracolumbar fractures on internal fixation are similar, but general spine system has some advantages such as simple to be operated, save time, less bleeding, stable fixation and good reduction. General spine system combined with paraspinal muscle approach is a good method to repair thoracolumbar spine fracture.