Objective To investigate the differential expression of P57kip2 and CDK5 in neural tube defects t(NTD) from the normal ,and provide the clue for the research of the molecular mechanism of the normal neurula formation .Methods A cDNA mi-croarray containing 1 100 known genes was used to compare differences in P57kip2 and CDK5 gene expression between the normal control group and the retinoic acid(RA)-induced NTD group on embryonic(E) day 9 .5 and 10 .5 .Two differentially expressed genes were randomly selected from the two groups for Northern blotting to verify the results of the cDNA microarray .Results Compared the differences of between P57kip2 and CDK5 in normal and E9 .5 d ,E10 .5 d ,E9 .5 d-NTD ,E10 .5 d-NTD ,P57kip2 and CDK5 expression was significantly up-regulated in the before and after the formation of the normal neurulation ,but them showed a downward trend in retinoic acid (RA)-induced NTD(including two phase E9 .5 d and E10 .5 d) .Conclusion P57kip2 and CDK5 in-volved in the physiological process of NTD ,and provide the useful clue for the research of the molecular mechanism of the normal neurula formation .

Objective:To investigate the clinical effect of modified atlantooccipital decompression combined with occipitocervical internal fixation on Chiari type I malformation combined with syringomyelia and atlantoaxial dislocation.Methods:Twenty-five patients with Chiari I malformation combined with syringomyelia and atlantoaxial dislocation accepted by modified atlantooccipital decompression combined with occipitocervical internal fixation in our hospital from January 2011 to March 2019. The clinical data of these patients were retrospectively analyzed. The changes of peak velocity of cerebrospinal fluid in the dorsal part of the spinal cord, electrophysiological results, atlantodental interval (ADI) values, sizes of syringomyelia, and Chicago Chiari outcome scale (CCOS) scores before and after operation were compared.Results:The peak velocity of cerebrospinal fluid in the dorsal spinal cord after surgery ([3.25±0.47] cm/s) was statistically higher in these patients than that before surgery ([2.13±0.19] cm/s, P<0.05). As compared with the preoperative results, ADI values, sizes of syringomyelia, and proportion of patients with abnormal electrophysiological monitoring at 6 months after surgery were significantly decreased, and CCOS scores at 6 months after surgery were significantly increased ( P<0.05). There were no new nerve function damage, infection, cerebrospinal fluid leakage, paralysis, respiratory failure or death. Conclusions:Modified atlantooccipital decompression combined with occipitocervical internal fixation plays effective role in atlantooccipital decompression and atlantoaxial anatomical reduction in patients with Chiari malformation type I combined with syringomyelia and atlantoaxial dislocation. The remission rate of syringomyelia is high, the symptoms and signs improve obviously, and the postoperative complications are less.