The Ca2+-ATPase of sarcoplasmic reticulum is a Ca2+ pump that plays a key role in regulating cytosol calcium concentration in muscle cells. It undergoes a sequential conformational transition during the transport process. According to the classical E1/E2 theory, in the E1 state the binding sites have high affinity and open to the cytoplasm, whereas in the E2 state the binding sites have low affinity and face the luminal side. Crystal structures of several states during the reaction cycle of Ca2+-ATPase have been solved recently, including a Ca2+-bound form (E1-2Ca2+), a Ca2+-unbound form stabilized by a potent inhibitor thapsigargin (TG) (E2-TG), an ATP-bound form (E1-ATP), an E1-P-ADP state, and an E2-Pi state. The details of these crystal structures and the relationship between structure and function of Ca2+-ATPase during reaction cycle were summarized, and the issues to be addressed in future research were raised.

Objective:To explore the changes in somatosensory evoked potential (SEP) in rats with spinal cord injury (SCI) and the effects of relieving spinal cord compression at different times on recovery and the evoked potential.Methods:Seventy Sprague-Dawley rats were randomly divided into a control group of 10 and an experimental group of 60. The experimental group was further divided into a mild injury group of 10, a moderate injury group of 40 and a severe injury group of 10. Spinal cord injuries with different severities were established in the experimental group using a self-made percussion device. The rats′ SEPs were measured before the injury, and 5 minutes, 1 hour, 6 hours, 3 days and 7 days afterward. Some of the rats receiving decompression treatment.Results:The more seriously the spinal cord was injured, the longer was the latency and the smaller was the amplitude. Both differences were statistically significant. Rats with longer compression time had significantly longer incubation periods and greater decreases in the amplitude. After relieving the compression, rats from whom it had been relieved earlier had quicker amplitude recovery. For rats under compression for 30 minutes, their amplitude was the lowest seven days later.Conclusions:For spinal cord injury, longer compression time can lead to more significant changes in the latency and amplitude of SEP, with the change in the amplitude more significant than that in the latency.

Objective To investigate the effect of different pore sized hydroxyapatite for promoting bone vascularization in tissue engineering.Methods Male Wistar rats were randomly divided into three groups,named group A,B and C,which were im-planted hydroxyapatite bioceramics compositing 4 μg bone morphogenetic protein with different aperture of 200 -300,350 -450, 500-600 μm in the back subcutaneously.The size of each block was 5 mm×5 mm×1 mm in a weight about of 40.0 mg.After im-plantation,the animals were killed and the implants and the surrounding tissue were taken out at the first,second,third and forth week respectively.HE staining of histological analysis was used to detect the situation of local neovascularization.Results There was significant difference between second and third week in group A.Comparing the area of vascularization at different time points in group B and group C,there were significant difference in the comparison of intragroup (P <0.05 ).During the first week after surgery,there was only group C that had the area of vascularization.During the second and forth week after operation,the area of vascularization in group B and group C were significant higher than group A (P <0.05).The C group showed a great deal of new-born blood vessels and clear formation of bone trabeculae.Conclusion The hydroxyapatite bioceramics of 500-600 μm could better promote vascalarization of tissue engineering in bone.

Objective] To amplify and sequence the light chain of anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum. [Methods] By comparing the conserved regions at each end of the nucleotide sequences of murine germ line genes enco ding FR1 and FR4 regions of immunoglobulin light chain variable regions, we designed a set of primers for amplification of V L gene. The hybridoma cells secreting anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum were cultured and their genome DNAs were extracted and used as templates for PCR. The PCR product was then cloned into pUC19 vector. The recombinants were sequenced by Sanger′s method. The V L gene was compared with GenBank and published mouse V L genes. [Results] The full length of V L gene was 318 bp. The V L gene was a member of mouse Ig ? light chain subgroup IV and generated from rearrangement of germ line V and J? 4 genes. The V L gene sequence has been registered by GenBank(accession No. AF206720). [Conclusion] The obtained V L gene was a potentially functional gene of anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum .