Objective To construct a regulatable plasmid containing single chain fusion gene of murine interleukin-12 (mIL-12) which was regulated with mifepristone (RU486) and explore its expression in vitro. Methods The p40 and p35 subunit sequence of mIL-20 were respectively obtained from the plasmid GCp35Ep40PN by polymerase chain reaction (PCR) and they were cloned into pCA14 plasmid after introducing a linker by overlap PCR. The single chain mIL-12 gene was comfirmed by sequencing and subcloned into pRS-17 vector which contains RU486 regulator cassette. The positive clone named pRS-RUmIL-12 was identified by restriction endonuclease digestion and PCR. Lipofectamine 2000 was used to transfect the pRS-RUmIL-12 to HEK293 cells followed by manufacturer’s recommendations. The protein concentration of mIL-12 induced with RU486 in supernatant of the transfected HEK293 cells was measured by ELISA. Results The sequence of single chain mIL-12 what we obtained was the same as the expected result. The results of restriction endonuclease digestion and PCR showed that the RU486-inducible regulatory vector (pRS-RUmIL-12) was successfully constructed. No significant mIL-12 protein concentration in supernatant of HEK293 cells activation was measured without the inducer RU486, whereas higher concentration of the mIL-12 protein was observed in the presence of RU486. The relationship of concentration of the mIL-12 protein and RU486 was positive correlated under definite range. Conclusion A regulatable eukaryotic expression plasmid of mIL-12 single chain fusion gene was constructed, which could be used in the further research of gene regulation and gene therapy.
Objective To amplificate,clone and sequence the thymidine kinase (TK) gene of herpes simplex virusⅡ(HSVⅡ); to construct and appraise the fusion gene eukaryon expression vector, pcDNA3/HSVⅡ TK/angiostatin. MethodsThe Hep2 cells were infected by HSVⅡ Sav strain. HSVⅡ genomic DNA was purified from the Hep2 cells suspension and used as template to run PCR for TK gene amplification. The amplified products were cloned into PC DNA3 vector and sequenced. The vector pcDNA/HSVⅡ TK was cut by endonuclease. The gained TK gene was cloned into eukaryon expression vector. pcDNA3/angiostation, which had been constructed. ResultsCoding region of HSVⅡTK gene consisted of 1 128 bp except stop code, it encoded 376 amino acids.After cutting the new vector by endonuclease Hind Ⅲ and BamH Ⅰ,we gained the following gene fragment: 1000 bp (TK) and 700 bp (angiostation).Conclusion The fusion gene eukaryon expression vector， pcDNA3/HSVⅡ TK/angiostatin has been constructed.
Objective To discuss the selection of anterior or posterior or a combination of anterior and posterior surgical treatment of lower cervical dislocation. Methods A retrospectively study was performed on 28 patients with lower cervical dislocation who received operative treatment between January 2005 and October 2008. There were 19 males and 9 femaleswith an average age of 38 years (range, 19-57 years), including 21 cases of fresh dislocation and 7 cases of old dislocation. The time from injury to hospitalization was 3 hours to 58 days. According to Allen classification, all cases had flexion injury, including 19 cases of degree I dislocation, 2 cases of degree II, 5 cases of degree III, and 2 cases of degree IV. At admission according to Frankel classification, 7 cases were rated as grade A, 4 as grade B, 9 as grade C, 3 as grade D, and 5 as grade E. All patients received open reduction, internal fixation, and il iac bone graft spinal fusion. Of them, combined anterior and posterior approach operation were given in 4 cases, single anterior operation in 22 cases, and single posterior operation in 2 cases. Results All operations were completed successfully and the spinal cord injury did not deteriorate after operation. Esophageal fistula occurred in 1 case receiving anterior approach operation and was cured after 1 month. Infection of wound occurred in 1 case and was cured after dressing change. The other incisions healed by first intention. One case (Frankel grade A) died of pulmonary infection 6 weeks after operation. Twenty-seven patients were followed up 21-38 months. Two cases suffered from shoulder pain 12 months after operation. X-ray films showed complete reduction, normal height of vertebral space and normal sequence of cervical spine after operation. All cases obtained bone fusion after 3.5-6.0 months of operation (4.2 months on average). Frankel grades were improved in different degrees after operation. Conclusion The operation plan of lower cervical dislocation should be determined by the neurologic status of the patient, and the classification of the injury as a unilateral or bilateral dislocation. Anterior cervical discectomy, fusion, and fixation were available in the lower cervical dislocation.
Objective To investigate the surgical method and prel iminary cl inical result of managing the patient with lumbar burst fracture but not suitable for single-level fixation and fusion surgery with the reservation of the fractured vertebral body and the anterior decompression. Methods From September 2007 to December 2008, 11 patients with lumbar burst fracture underwent the removal of the posterior superior corner of the injured vertebral body, the removal of the inferior intervertebral disc adjacent to the injured vertebral body, bone graft fusion, and internal fixation. There were 8 males and3 females aged 21-48 years old (average 29.4 years old). All the fractures caused by fall ing from high places. Imaging exams confirmed all the fractures were Denis type B burst fracture. The fracture level was at the L1 in 4 cases, the L2 in 4 cases, the L3 in 2 cases, and the L4 in 1 case. Before operation, the nerve function was graded as grade B in 4 cases, grade C in 3 cases, and grade D in 4 cases according to Frankel scales; the visual analogue scale (VAS) was (7.30 ± 0.98) points; lateral X-ray films displayed the kyphosis Cobb angel was (24.94 ± 12.21)°; the adjacent superior and inferior intervertebral disc height was (12.78 ± 1.52) mm and (11.68 ± 1.04) mm, respectively; CT scan showed the vertebral canal sagittal diameter was (9.56 ± 2.27) mm; CT three-dimensional reconstruction revealed that the intact part of the injured vertebra was less than 50% vertebra body height and the fracture l ine crossed the pedicle. The time from injury to operation was 3-11 days (average 4.8 days). The neurological and radiological evaluations were carried out immediately and 3 months after operation, respectively, and compared with the condition before operation. Results All the patients successfully underwent the surgery. The wound all healed by first intention. All the patients were followed up for 6-18 months (average 14 months). All the patients had a certain degree of nerve function recovery. The Frankel scales in all the patients were increased by 1-2 grade immediately and 3 months after operation. The VAS score was (2.80 ± 1.49) points immediately after operation and (1.54 ± 0.48) points 3 months after operation, suggesting there were significant differences among three time points (P lt; 0.05). The vertebral canal sagittal diameter was significantly enlarged to (18.98 ± 4.82) mm immediately after operation and was (19.07 ± 4.37) mm 3 months after operation. The Cobb angle was (7.78 ± 4.52)° immediately after operation and (8.23 ± 3.57)° 3 months after operation. There were significant differences between before and after operation (P lt; 0.05). For the adjacent superior and inferior intervertebral disc height, there was no significant difference when the value immediately or 3 months after operation was compared with that of before operation (P gt; 0.05). X-ray films and CT scan 3 months after operation showed good internal fixation without theoccurrence of loosing and displacement. Conclusion For the treatment of lumbar burst fracture, the method of reserving the injured vertebral body and anterior decompression can decompress the vertebral canal and shorten the duration for bony fusion.
Objective To evaluate the therapeutic effects of expandable pedicle screw (EPS) combined with interbody fusion cage on lumbar spondylolisthesis. Methods From June 2004 to March 2008, 23 patients with lumbar spondylolisthesiswere treated, including 9 males and 14 females aged 24-72 years old (average 48.7 years old). The course of the disease varied from 6 months to 6 years (average 30.4 months). There were 18 cases of degenerative spondylol isthesis and 5 of isthmic spondylolisthesis, including 1 case at L3,4 level, 14 at L4,5 level, and 8 at L5 and S1 levels. There were 17 cases of grade I, 4 of grade II, and 2 of grade III (including 1 case of recurrent L5 spondylolysis) according to Meyerding classification system. Posterior lumbar interbody fusion was performed using 48 PLIVIOS interbody fusion cages, and spondylolisthesis reduction and internal fixation were conducted using 84 pieces of EPS. The indications for use of EPS were initial operation with bone mass reduction or osteoporosis, reoperation of previous pedicle instrumentation, intraoperative screw relocation, sacral anchoring, and construct reinforcement. Cl inical outcomes, radiographic reduction of spondylol isthesis and bone fusion of lumbar interbody were evaluated based on JOA score, Boxall index, and Cook criteria. Results The incision healed by first intension in all cases except for one revision case that suffered from postoperative cerebrospinal fluid leakage and obtained delayed-healing without infection 23 days after operation using conservative treatment. No operative compl ications such as nerve and organ injuries were found.All cases were followed up for 12-39 months (average 17.8 months). X-ray exams of spine AP, lateral, fully extended position and fully flexed position view showed all 84 EPS were fully expanded within vertebral body. The improvement rate of JOA at the final follow-up visit was markedly effective in 14 cases, and effective in 5 cases, and noneffective in 4 cases, with a total effective rate of 82.61%. Anatomic reduction was achieved in 14 cases, improvement was obtained in 6 cases, no improvement was observed in 3 cases, and the reduction rate was 86.69%. Lumber interbody fusion was achieved in 20 cases, fixation was achieved in 2 cases, failure was observed in 1 cases, and the fusion rate was 86.69%. Conclusion EPS in complex with interbody fusion cage provides effective reduction, internal fixation and interbody fusion for the reconstruction of lumbar spondylolisthesis.
To explore the treatment of multi-segmental lumbar disc herniation and spinal canal stenosis by laminectomy, removal of nucleus pulposus, fusion of intra-transverse process and general spine system(GSS) fixation. Methods From January 2004 to January 2006, 21 patients with multi-segmental lumbar disc herniation and spinal canal stenosis were treated by laminectomy, removal of nucleus pulposus and GSS pedicle screw spinal system. There were 14 males and 7 females with an average age of 53 years ranging from 46 to 61 years, and with an average disease course of 18 months ranging from 8 months to 15 years. All of the patients were examined by X-ray with AP position, lateral position and dynamic lateral position, CT and MRI, and all of them proved to be with multi-segmental lumbar disc herniation and different degrees of spinal canal stenosis. A total of 47 nucleuses were picked out, and 47 instable segments were filled in with granule selfbone. Results There were 21 patients who were followed up for 1 to 2 years with an average of 13 months. All patients achieved successful fusion and bony union postoperative from 8 to 12 months, and no artificial joint was formed. As to the cl inical results in 21 cases, according to the Macnab outcome criteria, 14 were excellent, 6 were good and 1 was poor, the excellent and good rate was 95.2%. Conclusion The methods of laminectomy, removal of nucleus pulposus, fusion of intra-transverse process and GSS system fixation are effective in treatment of multi-segmental lumbar disc herniation and spinal canal stenosis．
Objective To compare the therapeutic effect of transforaminal lumbar interbody fusion (TLIF) and posterior lateral fusion (PLF) in treatment of thoracolumbar spine fracture and dislocation. Methods From January 2005 to July 2007, 35 patients (22 males, 13 females, aged 17-53 years old) with thoracolumbar spine fracture and dislocation (T11-L3) received posterior open reduction and pedicle nail-stick system internal fixation. Among which, 14 patients underwent TLIF(group TLIF), and the rest 21 patients underwent PLF (group PLF). According to AO classification, group TLIF had 3 cases of A3, 7 cases of B and 4 cases of C, while group PLF had 4 cases of A3, 10 cases of B and 7 cases of C. Based on American Spinal Injury Association (ASIA) Scoring Standard formulated in 2000, the motor score of group TLIF and group PLF was (50.6 ± 3.6) and (50.8 ± 4.2) points, respectively; and the sensory score was (170.5 ± 42.7) and (153.8 ± 23.7) points, respectively. No significant difference was noted between 2 groups in general information (P gt; 0.05). Results The operation time of group TLIF and group PLF was (316 ± 32) minutes and (254 ± 27) minutes, and the blood loss of group TLIF and group PLF was (487 ± 184) mL and (373 ± 72) mL, indicating there were significant differences between 2 groups (P lt; 0.05). Wounds of all patients were healed by first intention and there was no death, aggravation of neurological function impairment and compl ication of internal fixation instrument loosening and breaking. All 35 cases were followed up for 9-23 months with an average of 14.6 months. Postoperatively, the thoracolumbar bone fusion rate of group TLIF and group PLF was 100% and 85.7%, respectively, indicating there was a significant difference (P lt; 0.05). At 3 months after operation, the motor score of group TLIF and group PLF was increased by (10.4 ± 10.0) and (9.4 ± 9.3) points, respectively; and the sensory score was upgraded by (26.5 ± 22.8) and (28.8 ± 28.4) points, respectively, showing there were no significant difference (P gt; 0.05). At immediate moment, 3, 6 and 12 months after operation, the spine height restoration of group TLIF was (5.4 ± 2.1), (5.4 ± 1.9), (5.4 ± 1.4) and (5.3 ± 1.3) mm, respectively; while it was (5.3 ± 2.6), (5.3 ± 2.2), (4.8 ± 3.1) and (4.2 ± 3.6) mm for group PLF. Meanwhile, the Cobbangle recovery of group TLIF was (14.5 ± 3.5), (14.5 ± 3.6), (14.4 ± 3.4) and (14.4 ± 3.6)º, respectively; while it was (14.3 ± 2.7), (14.2 ± 3.1), (12.2 ± 2.8) and (11.7 ± 3.3)º for group PLF. Concerning the spine height restoration and the Cobb angle recovery, no significant difference was observed between 2 groups at immediate moment and 3 months after operation (P gt; 0.05), but significant differences were noted at 6 and 12 months after operation (P lt; 0.05). Conclusion For the treatment othoracolumbar spine fracture and dislocation, TLIF is superior to PLF in bony fusion and restoration of spine column height.
Objective To evaluate the therapeutic effect ofthe two-level cervical artificial disc replacements combined with the nearby segments fused for the multi-level disc herniations and to investigate their interaction during the treatment. Methods The patient undergoing surgery was diagnosed as having intervertebral disc herniations in the C3-7 intervertebral discs. During the operation, the C4-6 discs were replaced with two Bryan artificial discs while the C3,4 and C6,7 discs were removed, followed by the bone grafting and the Zephir instrumentation. The range of motion (ROM) was assessed before and immediately after operation by the flexion-extension radiography. The patient’s functional exercise began as early as 2 days after operation and lasted for 3 weeks, followed by immobilization for 3 months. Results According to the follow-up for 1 year and 2 months, the patientcould move his neck in all directions without pain. The spinal and neural symptoms were significantly alleviated. ROM was close to the normal level postoperatively.Conclusion Artificial disc replacement combined with bone grafting and fusion is a new way to treat multilevel disc herniations surgically, with good clinical results. Early cervical functional exercise followed byrestriction is an effective way to deal with the contradiction of motion and immobilization.
Objective To study operative methods of treating upper cervical spine instability without injury. Methods Twentythree cases were treated by internal fixation with autologous bone grafts. Atlantoaxial arthrodesis were performed in 10 cases with Apofix interlaminar clamp(5 cases), Atlas cable system(3 cases) and Brookes(2 cases). Occipitocervical fusion were performed in the other 13 cases by using of CD-cervical(3 cases), Cervifix(8 cases) and Ustick fixation(2cases). Results All the 23 cases were followed up for 2.5 years in average (ranged from 6 months to 5 years). Solid arthrodesis was obtained in all 23 cases . Six months after operation, of the 20 cases with preoperation nervous lesion, improvement was achieved in 16 cases. According to JOA standard and Hirabashiformula,the rate of improvement was 27.1%.Conclusion Posterior fusion is recommended for upper cervical unstability.
OBJECTIVE: To observe the early clinical results with degenerative lumbar instability treated with transpedical screw fixation and intertransverse process autogenous bone grafting. METHODS: From September 2000 to February 2002, 19 patients (5 males and 14 females) of degenerative lumbar spine instability were treated with decompression for spinal canal stenosis, transpedical screw fixation and intertransverse process autogenous bone grafting. The locations of degenerative lumbar spine instability were between L4 and L5 in 10 patients, between L3, L4 and L5 in 4 cases, between L3 and L4 in 3 cases, between L5 and S1 in 2 cases. The results were evaluated after operation. The preoperative clinical symptoms disappeared completely as excellent results, relieved obviously as good results, improved as fair results and unrelieved or worsened as poor results. RESULTS: Seventeen patients were followed up for 4-18 months with an average of 8.1 months. The results of the treatment were excellent in 12 patients, good in 4 patients and fair in 1 patient. The excellent and good rate was 94.1%. Intertransverse process arthrodesis was obtained after 6 months of operation in all cases. No loosened and broken instruments occurred. CONCLUSION: The advantages of degenerative lumbar spine instability treated with transpedical screw fixation and intertransverse are reliable fixation, high successful rate of fusion and less influence on spinal canal. The above results show satisfactory clinical outcome.