ABSTRACT
BACKGROUND: Recent literatures have showed that percutaneous kyphoplasty can effectively avoid nerve damage, pulmonary embolism, and insufficient vertebral height and other security risks when bone cement is infused into affected vertebrae in percutaneous vertebroplasty. OBJECTIVE: To compare the effect of percutaneous kyphoplasty and percutaneous vertebroplasty in repair of osteoporotic vertebral compression fractures. METHODS: A total of 106 patients with senile osteoporotic vertebral compression fractures were randomly divided into trial group and control group (n=53 per group). Patients in the trial group were treated with percutaneous kyphoplasty, and those in the control group treated with percutaneous vertebroplasty. Al patients were fol owed up for 6 months after repair. The vertebral compression deformation, bone cement distribution, midline vertebral bone cement condition, vertebral height restoration, bone cement leakage, vertebral kyphosis, progressive spinal col apse, nerve damage, as wel as visual analog scale scores and Oswestry disability index scores in these two groups were compared. RESULTS AND CONCLUSION: Compared with the control group, there was less bone cement leakage and vertebral compression deformation in the trial group. Moreouer, in the trial group, bone cement distributed uniformly, vertebral height restoration was good and effective, pain was obviously relieved, and the probability of vertebral kyphosis, progressive spine col apse and nerve damage was significantly reduced (al P < 0.05). These results suggest that percutaneous kyphoplasty can effectively relieve the pain of patients with osteoporotic vertebral compression fractures, restore vertebral body height and reduce the incidence of complications, which effectively guarantees the postoperative restoration of motor function.
ABSTRACT
Commonly, the interbacterial transfer of circular plasmids is initiated by nicking at an internal sequence, oriT, followed by transferring one strand as single-stranded DNA through a type Ⅳ secretion channel on cell membrane. In contrast, Streptomyces conjugative linear plasmids, containing a free 3'-end but a protein-capped 5'-end, can potentially undergo cell-to-cell transfer by transfer of non-nicked DNA. It was reported that circular derivatives of the Streptomyces lividans linear plasmid SLP2, as well as the parental linear plasmid itself can transfer efficiently. And the genetic requirements for such transfer was described. Efficient transfer of plasmid requires six co-transcribed SLP2 genes, encoding a Tra-like DNA translocase, cell wall hydrolase, two cell membrane proteins that interact with an ATP binding protein, and a protein of unknown function. Reduced transfer efficiency of plasmid from SalⅠ R-/M-to Sal Ⅰ R/M hosts argues that transfer of both the circular and linear forms of the plasmid involves double-stranded DNA. These results suggest that conjugal transfer occurs by a similar mechanism for SLP2-derived linear and circular plasmids, and cellular membrane/wall functions in the transfer process.