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BACKGROUND:The human telomerase reverse transcriptase gene (hTERT) transfected into target cel s can play an important role in target cel proliferation and differentiation by increasing telomerase activity and maintaining telomere length. OBJECTIVE:To explore the effect of hTERT transfection on telomerase activity and biological characteristics of precartilage stem cel s culured in vitro. METHODS:Precartilage stem cel s cultured in vitro were subjected to hTERT gene transfection via a retrovirus vector pLXSN. Meanwhile, control and negative control groups were set up. After transfection, TRAP-ELISA assay was used to detect telomerase activity;RT-PCR and western blot employed to detect hTERT mRNA and protein expressions;cel counting kit-8 used to detect cel proliferaiton based on cel growth curve;and flow cytometry adopted to detect cel cycle and distribution. RESULTS AND CONCLUSION:The telomerase activity was significantly increased at 48 hours after hTERT gene was transfected into the precartilage stem cel s. After transfection of hTERT, hTERT mRNA and protein levels were significantly increased, the cel growth rate was significantly increased, the proportion of cel s at G 0/G 1 phase was decreased, and the number of S-phased cel s increased compared with the control group and negative control group. There were significant differences among the groups (P<0.05). In conclusion, hTERT transfection via retrovirus vector pLXSN can promote the proliferation of precartilage stem cel s in rats by increasing the telomerase activity.
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Objective To explore the influential factors of treatment of the intra-articular calcaneal fractures treated with calcaneal titanic alloy plate.Methods The treatment of intra-articularcalcaneal fractures with calcaneal titanic alloy plate was reviewed.Thefalling height, weight, complication, Sanders evaluation method,mechanism of injured, the change degree of B(o)hler and Gissane angle were recorded and compared.One-way ANOVA, Chi-Square Tests and logistic test were applied to evaluate the relationship of these factors.Results According to AOFAS scale system, the average recovery score was 86.35, excellent rate was 91.6%.Binary logistic stepwise regression showed that the correlation between weight and resu1ts of treatment was statistically significant( P ＜0.01 ).The correlation between the period before operation and the recovery score was statistically significant( P ＜0.01).Sanders evaluation method was statistically significant ( P ＜0.05).The correlation between preoperative B(o)hler'sngle and Gissane's angle and the postoperative functional recovery score was statistically significant ( P ＜ 0.05) .Conclusions Calcaneal titanic alloy plate used in treatment of intra-articular calcaneal fracturcs was a good method.The weight, the period before operation, level of trauma and the B(o)hler's angle and Gissane's angle influenced the treatment effect.
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Objective To discuss three methods to treat intra-articular calcaneal fractures with malunion, and to investigate the indications and significances of the operative treatment. Methods From June 2002 to March 2004, 28 intra-articular calcaneal fractures with malunion patients (26 males and 2 females, 30 feet) suffered operations. The average age of these patients was 39.2 years old (range, 23-59 years). The malunion happened at left feet in 15 patients, right feet in 11, and bilateral feet in 2. The mean duration between injury and operation was 3.3 months (range, 2-5 months). All cases used improved "L" incisions at lateral of heels. 13 patients (14 cases) did open reduction and internal fixation; 9 patients (10 cases) operated calcaneal osteotomy to reserve subtalar joint and correct deformity with apophysis excision, then used internal fixations; 6 patients (6 cases) used correct deformity with apophysis excision, calcaneal cumulus reconstruction and subtalar arthrodesis. The calcaneal lateral and axial X-ray and CT films were got to measure the B?觟hler angle, Gissane angle, calcaneal width and axial length, and height of calcaneal body-thalamic portion before and after operation. There were siginificant differences at all index before and after operation(P