Objective To investigate the effect of caffeine and cisplatin induced apoptosis of osteosarcoma cell line(OS-732), and to explore the potential mechanism of caffeine enhancing cytotoxic effect of cisplatin in osteosarcoma cell line. Methods The OS-732 cell line was cultured for 72 hours; treated with caffeine, cisplatin and caffeine combined with cisplatin for 72 hours respectively, the apoptosis rates of OS-732 cell line were analysed by flow cytometry. Mitochondrial transmembranous potentials were measured by cellular rhodamine 123 stain on flow cytometry. Apoptosis was assessed by electron microscope at 80 kV. Results The OS-732 cell line was cultured for 72 hours; treated with caffeine (5.0 mmol/L ), cisplatin (10.0 ?g/ml ) and caffeine (5.0 mmol/L ) combined with cisplatin (10.0 ?g/ml) for 72 hours respectively. The apoptosis rates were 2.50%, 10.62%, 31.62% and 57.44% respectively. The percentage of decline of mitochondrial transmembranous potentials were 8.12%, 26.45%, 17.82% and 38.26% respectively. Electron microscope revealed the characteristic apoptosis alterations,such as shrinking cellular chromatin condensation, crescent nucleus, cytoplasmic vacuoles and so on. Conclusion Caffeine and cisplatin can induce apoptosis of osteosarcoma cell line(OS-732), while the cell line treated with caffeine and cisplatin simultaneously, the apoptosis rate was increased obviously. The induction of apoptosis of osteosarcoma cell line by caffeine may be one of potential mechanism enhancing cytotoxic effect of cisplatin in osteosarcoma cell line.

Objective To investigate the causes of re-fractures of non fracture vertebral body after percutaneous kyphoplasty (PKP).Methods 512 patients (618 vertebral bodies) treated with PKP because of osteoporosis VCFs were recruited from June 2010 to June 2014.There were 107 males (121 vertebral bodies) and 405 females (497 vertebral bodies) with the mean age of 70.38±7.59 years old (51 to 91 years).There were 406 single segment fracture and 106 double segment fractures cases,and the fracture segments were T4 to L5.The T value of the patients' bone mineral density (BMD) was from-1.0 to-5.2 SD.The clinic characteristics of all the patients including age,sex,body weight,body height,body mass index (BMI),BMD score of the spine,volume of bone cement,restoration rate of anterior/middle vertebral height,postoperative complications (pulmonary embolism,bone cement leakage,nerve injury),and treated vertebral level were analyzed.Results 52 patients (10.16％,52/512) experienced refractures of non fracture vertebral body after kyphoplasty,and 4 experienced re-fracture of the fracture vertebral body after kyphoplasty.The average age of the 52 patients was 71.88±7.74 years old,meanwhile,the ratio of female was 94.23％ (49/52),the mean T value of BMD-4.03±0.60 SD,the ratio of initial double segment fractures 51.92％ (27/52).In addition,among the 456 cases with no fracture,the average age was 70.21±7.56 years,the ratio of female was 77.19％ (352/456);the mean T value of BMD was-2.89±0.55 SD;the ratio of initial double segment fractures was 17.32％(79/456).The data above (age,T value of BMD and initial double segment fractures) were all with statistical significant differences.Whereas the BMI,volume of bone cement,intervertebral disc leakage and restoration rate of anterior/middle vertebral height had no significant difference between the two groups.Furthermore,in the re-fracture of non fracture vertebral body group,32 cases (61.54％,32/52) were nonadjacent fractures,and 20 (38.46％,20/52) were adjacent fractures.Conclusion Osteoporosis degree,female and initial double segment fractures were major risk factors in the development of re-fracture of non fracture vertebral body after PKP.

Objective To investigate the morphological changes, apoptosis and brain-derived neurotrophic factor mRNA(BDNF mRNA)expression in rat conus medullaris induced by cauda equine compression, and to discuss the possible mechanisms. Methods Ninety male SD rats were divided into 3 groups: normal control, sham operation,and cauda equine compressed. The animals were sacrificed and took samples in 30 min, 2 hours,4 hours,8 hours,1 day,3 days,1 week,2 weeks,3 weeks after cauda equine compression model were created. The morphological study concerned with cauda equina and conus medullaris was done under light microscope and transmission electron microscope. TUNEL staining and in situ hybridization staining were used to investigate apoptosis and BDNF mRNA expression changes. The positive cells in 1mm2 were calculated,and the data were disposed through one way analysis of variance. Results Histological observation showed notable alteration of cauda equina and neurons in conus medullaris. The positive cells of TUNEL and BDNF mRNA in situ hybridization staining increased in 8 hours and 4 hours after cauda equina compressed,and both reached the climax in 3days after cauda equina compressed. At the time 3weeks after cauda equine compressed, the positive cells were still much higher than that of the control groups. Conclusion The compression of cauda equina will result in neurons morphological changes and apoptosis in medullary cone,and cause central neuron un-reversible injury. It might be one of the reasons why the prognosis is poor in cauda equina syndrome. Neurons and glial cells may produce BDNF by themselves to survival from cauda equina compression.