Morphological changes apoptosis and BDNF mRNA expression in the conus medullaris neurons in cauda equina compressed rats / 解剖学报

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.

Experimental study on caffeine and cisplatin induction apoptosis of osteosarcoma cell line(OS-732) / 中华骨科杂志

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.