BACKGROUND:Generaly, the stent surface modification, especialy seeding cels, may accelerate or cause stent endothelium, and cause restenosis for prevention of in-stent thrombosis.
OBJECTIVE: To develop the optimal conditions for vascular stents coated with bone marrow mesenchymal stem cels.
METHODS: Cerebrovascular stent was co-cultured with passage 3 bone marrow mesenchymal stem cels from rats at 1×106, 1×107, 1×108, and 1×109/L. Cels on the stents were examined with transmission electron
microscopy after 48 hours. A total of 160 male Sprague-Dawley rats were enroled, among which, 20 rats were as normal control group, and the remaining 140 were used for producing models of ischemic stroke that were
randomly sub-divided into seven groups at 8 weeks after modeling: stainless steel stent implanted group, polymer stent group, and different concentrations of cellstent composite groups. After 8 weeks of implantation, the
expression of vascular endothelial growth factor in these cels was examined by western blot assay. Rat platelet activation in different groups was determined by flow cytometry.
RESULTS AND CONCLUSION:Implanted stem cels were able to grow adherently on the stainless steel stent wal. When the planting cellconcentration was 1×107 cels/L, the cels and organeles were morphologicaly
normal and covered the stent surface wel. These coated cels also expressed vascular endothelial growth factor, suggesting that they functioned as endothelial cels, and they also significantly lowered platelet activation. When
co-cultured with 1×107/L bone marrow mesenchymal stem cels, the stent was covered wel with endothelial-like cels and had significant lower platelet activationin vivo.

Objective:To evaluate the cytotoxicity of colorized zirconia ceramics.Methods:Zirconia ceramic 3Y-TZP blocks were colorized by NH4 VO3 ,FeCl3 ,Co(NO3 )3 ,Ni(NO3 )3 and MoCl3 respectively.The cytotoxicity of colorized zirconia to L-929 cells was examined by immersion method and MTT assay.Results:During 3 days culture,L929 cells in all groups showed similar prolifera-tion and normal morphology.The toxicity gradation of all groups was 0 -I.Conclusion:Zirconia ceramics colorized with the 5 kinds of colorants has no cytotoxicity.

Objective To study the MRI features and its ultrastructural pathology basis in different myocardial injury areas after acute infarction.Methods 10 rabbits were given ligation of left anterior descending branch 24 hours to make pathologic models.All animals underwent conventional MRI,contrast media dynamic enhancement MRI,cine-MRI and dobutamine stress test.Myocardial blood flow was measured with radioactive micropheres to define risk regions.Ischemic and infarcted regions were defined as Even's blue and 2,3,5triphenyltetrazolium chloride(TTC)negative regions respectively,and made electron microscopy specimens to observe the changes of mitochondria and myofibril.The myocardial ultrastructural injury was scored and graded.Results There were no significant change on T 1WI,but the signal intensity on T 2WI increased significantly after AMI.The diseased myocardium became thinning were seen in 40% cases,and the abnormal flowing high signal were seen in 60% cases.The dynamic enhancement time-signal intensity curves were different in normal,ischemic and infarcted regions.Cine-MRI showed the cardiac wall movement impairing and the wall thick thinning,but the wall movement reinforcing and the wall thick thickening after dobutamine stress.The water content of ischemic and infracted myocardium were marked higher than normal myocardium.The myocardial blood flow in diseased regions were decreased significantly than that in normal regions.The volume density and numerical density of mitochondria in different injury regions showed significant differences.Conclusion MRI appearances of AMI were associated with the injury degree of myocardial ultrastructure and the residual myocardial blood flow.

Objective:To analyze the clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the Zista channel assisted by navigation for the treatment of lumbar spinal stenosis.Methods:The medical records of 156 patients who underwent surgery for lumbar spinal stenosis from January 2017 to January 2019 were retrospectively analyzed. The patients were divided into minimally invasive group, navigation open group and open group according to surgical method and navigation usage. 67 cases were treated with MIS-TLIF assisted by navigation in minimally invasive group. In the navigation open group, 31 cases underwent open TLIF surgery assisted by navigation, 58 cases were treated with open TLIF. The database was compared among the three groups including intraoperative blood loss, operative time, postoperative drainage, postoperative hospitalization time and complications. Evaluated the internal fixation and fusion according to CT, assessed the surgical results according to VAS, ODI and SF-36. The clinical effects were evaluated by MacNab scores at the last follow-up.Results:The amount of intraoperative blood loss in the minimally invasive group 116.39±25.88 ml was less than that in the navigation open group 293.94±61.67 ml and the open group 396.97±92.58 ml, and the difference was statistically significant ( F=296.01, P<0.001). The intraoperative blood loss in the navigation open group was less than that in the open group. The postoperative drainage in the minimally invasive group 80.55±27.29 ml, was less than that in the navigation open group 299.94±50.32 ml and the open group 304.86±84.34 ml, and the difference was statistically significant ( F=273.14, P<0.001). The postoperative hospitalization time in the minimally invasive group 3.42±1.00 d was less than that in the navigation open group 7.16±1.39 d and the open group 7.31±1.69 d, and the difference was statistically significant ( F=154.49, P<0.001). There was no significant difference in the operation time ( F=0.15, P=0.859). At 2 weeks and 3 months after operation, the VAS score of low back pain in the open navigation group (3.84±0.82, 1.90±0.91) and the open group (3.67±0.92, 1.91±0.90) and ODI in the navigation open group (34.74%±11.66%, 28.68%±8.19%) and the open group (32.21%±10.66%, 27.17%±9.59%) were lower than those in the minimally invasive group (1.70±0.92, 0.96±0.73), (18.33%±7.43%, 19.15%±7.96%), and the difference were statistically significant [( F=96.63, P<0.001; F=25.12, P<0.001), ( F=45.59, P<0.001; F=18.99, P<0.001)]. The SF-36 score of the minimally invasive group 61.48±9.50 at the last follow-up was higher than that of the navigation open group 52.51±6.99 and the open group 53.48±7.66, and the difference was statistically significant ( F=18.97, P<0.001). In the same group, the VAS score, ODI score and SF-36 score at each follow-up time after surgery were statistical differences compared with those before surgery ( P<0.05). Postoperative follow-up CT showed that the fusion rate of the minimally invasive group was 94.0% (63/67), the navigation open group was 93.5% (29/31), the open group was 93.1% (54/58), and the difference between the three groups was not statistically significant (χ 2=0.05, P=0.978). The success rate and accuracy of one-time nail placement in the minimally invasive group and the navigation open group were higher than those in the open group, the difference was statistically significant (χ 2=17.17, P<0.001; χ 2=15.49, P=0.040). Dural rupture occurred in 1 patient in the minimally invasive group and 2 patients in the open group. The drainage and condition changes were closely observed after surgery. All patients were successfully extubated after surgery without complaining of other discomfort. One patient in the minimally invasive group had endplate destruction and mild intervertebral collapse during postoperative follow-up. There was 1 case of incisional fat liquefaction in each of the navigation open group and the open group. Subgroup analysis of the results of the three groups were roughly the same as the overall results. Conclusion:MIS-TLIF in the Zista channel assisted by navigation is a safe, effective, and worthy of promotion minimally invasive lumbar fusion surgery with the advantages of less trauma and faster recovery in the treatment of different types of lumbar spinal stenosis.