Objective To investigate the influence of calcitonin on bone mineral density and biomechanics around the artificial pros-thesis in ovariectomized diabetic rabbit model. Methods Fourteen femina New Zealand white rabbits at the age of 5 months old were select-ed, which weight 2.24 -2.65kg, averaging 2.26kg. First, the model of rabbit with diabetic osteoporosis was successfully established by the compound method of ovariectomy plus streptozotocin. Osteotomy in the middle part of femur was performed in both groups, fixation of artifi-cial prosthesis was done with 3.0 kirschner wire. After that, Rabbit models with diabetic osteoporosis were randomly divided into experimen-tal group and control group. Rabbits in the experimental group were treated with calcitonin 6U intramuscular injection once every other day. In control group, intramuscular injection of normal saline solution 1.5ml once every three days. Rabbit models of two groups were sacrificed in the 24th week. The BMD of the region of interest (ROI) around the prosthesis were detected before experiment and 8, 16 and 24 weeks after injection. After rabbits were killed, experimental femurs in both groups were complete removal and soft tissues were rejected. Determi-nation of the pull-out and torsion bone biomechanics experiments of prosthesis was done in both groups respectively. Results The BMD of ROI in the experimental group before operation was (0.1863±0.004)g/cm2 and (0.1753±0.005)g/cm2 in 24 weeks after operation, in control group before operation was (0.1865±0.002)g/cm2 and (0.1638±0.005)g/cm2 in 24 weeks after operation. There were significant difference between the two groups(P < 0.05). Biomechanical show that the pull-out strength in the experimental group was (312.68±8.73 )N/cm2 and (205.43±12.45 ) N/cm2 in control group. There were significant difference between the two groups(P < 0.05). The tor-sion strength in experimental group was (80.47±2.51) N/cm2 and (38.52±0.64) N/cm2 in control group. There were significant differ-ence between the two groups(P < 0.05). Conclusion Salmon calcitonin can reduce the bone turnover rate around prosthesis and decrease bone absorption in the rabbit of diabetic osteoporosis models, accelerate the bone formation around prosthesis, and increase the BMD. It can ameliorate the quality of bone around prosthesis, improve its biomechanics property, and increase the holding power between prosthesis and body mass. It is of clinical significance for the prevention and treatment of aseptic loosening artificial prosthesis.

Objective:To investigate the interaction between heat shock protein 90 (Hsp90) and silent mating-type information regulation 2 homolog 1 (SIRT1) and evaluate its effect on epithelial-mesenchymal transition (EMT) of lung cancer A549 cells.Methods:EMT model was established by treating lung cancer A549 cells with 5 μg/L transforming growth factor-β1 (TGF-β1), which was used as TGF-β1 group, and the normal lung cancer A549 cells were used as control group. The interaction between Hsp90 and SIRT1 in lung cancer A549 cells was detected by immunocoprecipitation method. The expression of Hsp90 gene was silenced by RNA interference technique, and the cells were divided into TGF-β1 group, TGF-β1+ siRNA-Hsp90-neg group and TGF-β1+ siRNA-Hsp90 group. Transwell invasion assay was used to investigate the effect of the interaction of Hsp90 and SIRT1 on the invasion ability of lung cancer A549 cells. The expressions of Hsp90, SIRT1, E-cadherin and vimentin were detected by Western blotting. The effect of inhibiting Hsp90 expression on the stability of SIRT1 protein and EMT of lung cancer A549 cells was observed.Results:After 48 h induction with TGF-β1, EMT characteristics of lung cancer A549 cells were induced successfully. The relative expression levels of Hsp90 protein in the control group and TGF-β1 group were 0.45±0.05 and 1.31±0.06, respectively, the relative expression levels of SIRT1 protein were 0.29±0.04 and 0.95±0.08, respectively, and there were statistically signigicant differences ( t=10.98, P=0.018; t=7.39, P=0.028). The results of immunocoprecipitation showed that there was an interaction between Hsp90 and SIRT1 protein in lung cancer A549 cells. The relative expression levels of Hsp90 in the TGF-β1 group, TGF-β1+ siRNA-Hsp90-neg group and TGF-β1+ siRNA-Hsp90 group were 0.75±0.07, 0.63±0.06 and 0.23±0.05, respectively, and there was a statistically significant difference ( F=18.85, P=0.012). The relative expression levels of SIRT1 in the above three groups were 0.99±0.08, 0.97±0.12 and 0.35±0.05, respectively, and there was a statistically significant difference ( F=16.52, P=0.014). The expression levels of Hsp90 and SIRT1 in the TGF-β1+ siRNA-Hsp90 group were significantly lower than those in the TGF-β1 group ( P=0.019, P=0.016). The numbers of cells passing Matrigel in the above three groups were 378.13±27.70, 323.52±19.82 and 142.51±22.54, respectively, and there was a statistically significant difference ( F=27.35, P=0.022). The number of cells passing Matrigel in the TGF-β1+ siRNA-Hsp90 group was significantly less than that in the TGF-β1 group ( P=0.028). The relative expression levels of E-cadherin in the above three groups were 0.31±0.02, 0.34±0.04 and 0.63±0.05, respectively, and there was a statistically significant difference ( F=19.39, P=0.031). The relative expression levels of vimentin in the above three groups were 0.33±0.02, 0.27±0.05 and 0.09±0.03, respectively, and there was a statistically significant difference ( F=12.58, P=0.012). The expression level of E-cadherin in the TGF-β1+ siRNA-Hsp90 group was significantly higher than that in the TGF-β1 group ( P=0.017), while the expression level of vimentin was significantly lower than that in the TGF-β1 group ( P=0.023). Conclusion:Hsp90 interacts with SIRT1, and Hsp90 inhibition can lead to the decrease of SIRT1 protein level. Hsp90 may play a role of molecular chaperone to maintain the conformation stability of SIRT1, and the interaction between Hsp90 and SIRT1 may be one of the molecular mechanisms for the occurrence of EMT and the enhancement of invasion ability of lung cancer A549 cells.

Objective To observe the correlations of pontine biological indicators on fetal brain median sagittal MRI with gestational week.Methods Data of head MRI of 226 normal fetuses without obvious abnormalities of central nervous system(normal group)and 17 fetuses with abnormalities(abnormal group)at gestational age of 23 to 38 weeks were retrospectively analyzed.Pontine biological indicators based on median sagittal MRI were obtained,including pons anteroposterior diameter(PAD),total pons area(TPA),pontine basal anteroposterior length(AP),pontine basal cranio-caudal length(CC),basis pontis area(BPA)and pontine angle of midbrain(MAP).According to the gestational week,the fetuses of normal group were divided into 8 subgroups.The distributing ranges of pontine biological indicators at different gestational weeks were analyzed,and the correlations of pontine biological indicators with gestational week in normal group were explored,and the developmental status of fetal pons in abnormal group were assessed.Results In normal group,PAD,TPA,AP,CC and BPA all showed linear positive correlation(r=0.887,0.914,0.787,0.866,0.865,all P＜0.001),while MAP was not significantly correlated with gestational week(P＞0.05).Among 17 fetuses in abnormal group,abnormal PAD or TPA was found each in 8 fetuses,abnormal AP was observed in 14,abnormal CC was noticed in 3 and abnormal BPA was found in 11 fetuses.Conclusion Fetal pontine biological indicators such as PAD,TPA,AP,CC and BPA on median sagittal MRI were positively correlated with gestational week,hence being able to be used for evaluating fetal pontine development.