ABSTRACT
Objective To investigate the potential mechanism that melatonin at higher concentrations inhibits the proliferation of human MG-63 osteosarcoma cells,so as to provide a certain experimental basis for the better application of melatonin in the treatment of diseases in Department of Orthopedics. Methods MG-63 cells cultured in vitro were treated with melatonin at a concentration of 4 mmol/L . Western blotting and real-time PCR method were used to analyze the effect of melatonin on the expression of cyclins and CDKs at protein and mRNA levels ,respectively. Results Western blotting and real-time PCR analyses showed that melatonin's inhibitory effect was possibly through the downregulation of cyclin D1 and CDK4 that related to the G1 phase,and downregulation of cyclin B1 and CDK1 that related to the G2/M phase. However,there was no obvious dif-ference of cyclin E,CDK2,and cyclin A,which were related to G1/S transition and S phase. Conclusion Melatonin may significantly inhibit hu-man osteosarcoma cell proliferation by inducing cell cycle arrest in a time-dependent manner,which is related to the downregulation of cyclin D1, CDK4,cyclin B1 and CDK1.
ABSTRACT
Objective To summarize the experience in early diagnosis and emergency treatment for combined thoracoabdominal injury (CTI). Methods Clinical data of 58 cases of CTI admitted to our hospital from June 2001 to August 2009 were analyzed retrospectively.All the patients were treated by closed drainage of thoracic cavity,of which 12 cases were treated with thoracotomy,31 with laparotomy,seven with thoracic and abdominal incisions and three with combined thoracoabdominal incision.Internal fixation for long limb bones was performed in 27 cases,spinal laminectomy and pedicle screw fixation in five and amputation in one. Results After operation,six cases were found to have adult respiratory distress syndrome (ARDS) and 12 cases were complicated with multiple organ dysfunction syndrome (MODS).Fifty-three cases were cured and five died. Conclusions CTI based multiple injuries are severe and complicated.CT scan in the early stage plays a significant role in the diagnosis of CTI and closed drainage of thoracic cavity is an important assurance of the security of abdominal operation.Early diagnosis,correct choice of operation procedures and reasonable handling order of injured organs can improve the successful rescue rate for multiple injury patients.