ABSTRACT
[Abstract] Objective To investigate the effect of hippocampal brain derived neurotrophic factor precursor (proBDNF) in cognitive dysfuction induced by social isolation. Methods Thirty C57BL / 6 J male mice (4-week old) were randomly divided into group house (GH,n = 15) and socially isolated (SI,n = 15) groups. The GH group (5 mice / cage) and SI group (1 mice / cage) were reared separately under the same conditions. The novel object recognition test and the novel place recognition test were used to evaluate the cognitive function. The expression of BDNF mRNA in the hippocampus was detected by Real-time PCR. The expression of BDNF and proBDNF in hippocampus was detected by Western blotting. Matrix metallopeptidase-9 (MMP-9) and tissue plasminogen activator (tPA) were extracellular enzymes that catalyzed the transformation of proBDNF into mature BDNF. Expression of MMP-9 and tPA mRNA in the hippocampus were detected by Real-time PCR. Results Compared with the GH group, the SI group showed significantly reduced discrimination ratio in the novel object recognition test and novel place recognition test. The result of Real-time PCR showed that there was no difference in the expression of BDNF mRNA between SI group and GH group. The result of Western blotting showed that the expression level of proBDNF in the hippocampus of SI group increased significantly compared with the GH group (P<0. 01),and no difference in BDNF expression was found between the two groups; Compared with the GH group, the BDNF/ proBDNF ratio in the hippocampus of SI group decreased. In addition, the result of Real-time PCR showed that the expression level of MMP-9 and tPA mRNA in the hippocampus of SI group decreased significantly compared with the GH group. Conclusion The social isolation-induced cognitive dysfuction in mice may be related to the up-regulation of proBDNF in the hippocampus.
ABSTRACT
<p><b>OBJECTIVE</b>To explore a operative approach and its effect to the central protrusion of lumbar intervertebral disc.</p><p><b>METHODS</b>From February 1999 to December 2005,34 patients with central protrusion of lumbar intervertebral disc were treated with an improved operative procedure. The study involved 25 males and 9 females with an average of 46.4 years (range, 35 to 63 years). The involved level of herniation were at L4,5 in 20 cases and L5S1 in 14 cases. Pains happened on one leg fixedly and seriously with another lightly in 21 cases, on one leg initially and lightly with another seriously later in 8 cases, on bilateral legs alike in 5 cases. Preoperative CT film showed central type in 8 cases and laterocentral type in 26 cases. The corresponding spinous process was resected on the basis of unilateral fenestration. The supraspinous ligament was retained and pulled to the opposite side for revealing spinal canal, and then diskectomy was done. The above procedure was named "fenestration with the spinous process resection".</p><p><b>RESULTS</b>All the 34 patients were followed up for 1 to 5 years. The outcome was evaluated according to the standard of HOU Shu-xun, 20 cases were excellent, 11 good and 3 fair. The total rate of excellent and good was 91.2%.</p><p><b>CONCLUSION</b>The "fenestration with the spinous process resection" not only completed decompression of spinal canal and diskectomy, but also retained opposite lamina and supraspinous ligament and maintained the stability of posterior vertebral column, which are a new improved approach for the central protrusion of lumbar intervertebral disc.</p>