[Treatment of stable degenerative lumbar spondylolisthesis with percutaneous endoscopic surgery through two different approaches].

OBJECTIVE: To assess the clinical effects of percutaneous endoscopic surgery through two different approaches for stable degenerative lumbar spondylolisthesis. METHODS: Sixty-four patients with stable degenerative lumbar spondylolisthesis who underwent percutaneous endoscopic procedures between January 2016 and December 2019 were divided into transforaminal approach group and interlaminar approach group according to surgical approaches, 32 patients in each group. There were 16 males and 16 females in transforaminal approach group, aged from 52 to 84 years old with an average of (66.03±9.60) years, L2 slippage in 4 cases, L3 slippage in 5, and L4 slippage in 23. There were 17 males and 15 females in interlaminar approach group, aged from 46 to 81 years old with an average of (61.38±9.88) years, L3 slippage in 3 cases, L4 slippage in 15, and L5 slippage in 14. Operative time, intraoperative fluoroscopy times, and postoperative bedtime were compared between two groups. Anteroposterior displacement values, interbody opening angles, and the percentage of slippage were measured on preoperative and postoperative 12-month dynamic radiographs. Visual analogue scale (VAS) of low back pain and lower extremity pain, and the Japanese Orthopaedic Association (JOA) score before and after surgery were observed, and clinical effects were evaluated according to the modified MACNAB criteria. RESULTS: All operations were successfully completed, and patients in both groups were followed up for more than 1 year, and without complications during follow-up period. ①There was no significant difference in operation time between two groups(P>0.05). Intraoperative fluoroscopy times were longer in transforaminal approach group than that in intervertebral approach group(P<0.05). Postoperative bedtime was shorter in transforaminal approach group than that in intervertebral approach group (P<0.05).② No lumbar instability was found on dynamic radiography at 12 months postoperatively in both groups. There were no significant differences in anteroposterior displacement values, interbody opening angles, and the percentage of slippage between two groups postoperative 12 months and preoperative 1 day(P>0.05). ③There was no significant difference between two groups in VAS of low back pain at 3 days and 1, 12 months after the operation compared with the preoperative(P>0.05), but the VAS of the lower extremity pain was significantly improved compared with the preoperative(P<0.05). Both of groups showed significant improvement in JOA score at 12 months compared with preoperatively(P<0.05). There was no significant difference in VAS of low back pain, lower extremity pain and JOA scores between two groups during the same period after surgery(P>0.05). According to modified Macnab criteria, excellent, good, fair and poor outcomes were 21, 7, 3 and 1 in transforaminal approach group respectively, and which in intervertebral approach group were 20, 7, 5 and 0, there was no significant difference in clinical effect between the groups(P>0.05). CONCLUSION: Intervertebral approach may reduce intraoperative fluoroscopy times and transforaminal approach can shorten postoperative bedtime, both approaches achieve satisfactory results in the treatment of stable degenerative lumbar spondylolisthesis with no progression of short-term slippage.

7ß-Methyl substituent is a structural locus associated with activity cliff for nepenthone analogues.

With the purpose of identifying novel selective κ opioid receptor (KOR) antagonists as potential antidepressants from nepenthone analogues, starting from N-nor-N-cyclopropylmethyl-nepenthone (SLL-020ACP), a highly selective and potent KOR agonist, a series of 7ß-methyl-nepenthone analogues was conceived, synthesized and assayed on opioid receptors based on the concept of hybridization. According to the pharmacological results, the functional reversal observed in orvinol analogues by introduction of 7ß-methyl substituent could not be reproduced in nepenthone analogues. Alternatively, introduction of 7ß-methyl substituent was associated with substantial loss of both subtype selectivity and potency but not efficacy for nepenthone analogues, which was not found in 7ß-methyl orvinol analogues. Surprisingly, SLL-603, a 7ß-methyl analogue of SLL-020ACP, was identified to be a KOR full agonist. The possible molecular mechanism for the heterogeneity in activity cliff was also investigated. In conclusion, 7ß-methyl substituent was a structural locus associated with activity cliff and demonstrated as a pharmacological heterogeneity between nepenthone and orvinol analogues that warrants further investigations.

[Biomechanical study of the stability of subaxial cervical anterior transpedicular screw fixation for three-column injury].

OBJECTIVE: To compare the stability of subaxial cervical anterior transpedicular screw(ATPS) fixation and three traditional fixations for three-column injury. METHODS: Six specimens of cervical spine were prepared. After measurememt of the range of motion(ROM) in intact state, the specimens were made into three-column injury models. The models were reconstructed with an anterior cervical cage, and stabilized by ATPS, anterior plate(AP), anterior plate + lateral mass screw(AP+LMS) and posterior transpedicular screw(PTPS). The ROM of the models in the four states were measured, and the results of data were compared after standardization. RESULTS: The normalized ROM of ATPS state in flexion-extension, lateral bending, axial rotation were(77.17±4.75)%, (82.00±2.61)%, (83.17±2.23)%, which were significant small than those in intact state(P<0.05). The normalized ROM of AP state in flexion-extension, lateral bending, axial rotation were(119.67±7.42)%, (116.33±7.53)%, (112.67±5.99)% , which were significant larger than those in intact state(P<0.05). The normalized ROM of AP in all directions were significant larger than those of ATPS(P<0.05). There was no significant difference between normalized ROM of PTPS state and those of ATPS state in flexion-extension and lateral bending(P>0.05). The normalized ROM of PTPS state in axial rotation was(6.83±2.48)% and was significant larger than that of ATPS state(P=0.009). The normalized ROM of AP+LMS state in flexion-extension was(68.50±2.43)%, which was significant smaller than that of ATPS state(P=0.003). There was no significant difference between the normalized ROM of AP+LMS state and those of ATPS state in lateral bending and axial rotation(P>0.05). CONCLUSIONS: Subaxial cervical three-column injury model reconstruction by ATPS can provide the adequate primary stability, of which biomechanics property is superior compared to AP and PTPS, and is similar to that of AP+LMS. It can be applied to the patients with no need to decompression and reduction through posterior approach.

Down-regulated miR-448 relieves spinal cord ischemia/reperfusion injury by up-regulating SIRT1.

MicroRNAs play a crucial role in the progression of spinal cord ischemia/reperfusion injury (SCII). The role of miR-448 and SIRT1 in SCII was investigated in this study, to provide further insights into prevention and improvement of this disorder. In this study, expressions of miR-448 and SIRT1 protein were determined by qRT-PCR and western blot, respectively. Flow cytometry was used to analyze cell apoptosis. The endogenous expression of genes was modulated by recombinant plasmids and cell transfection. Dual-luciferase reporter assay was performed to determine the interaction between miR-448 and SIRT1. The Basso, Beattie, and Bresnahan score was used to measure the hind-limb function of rat. The spinal cord ischemia reperfusion injury model of adult rats was developed by abdominal aorta clamping, and the nerve function evaluation was completed by motor deficit index score. In SCII tissues and cells treated with hypoxia, miR-448 was up-regulated while SIRT1 was down-regulated. Hypoxia treatment reduced the expression of SIRT1 through up-regulating miR-448 in nerve cells. Up-regulation of miR-448 induced by hypoxia promoted apoptosis of nerve cells through down-regulating SIRT1. Down-regulated miR-448 improved neurological function and hind-limb motor function of rats with SCII by up-regulating SIRT1. Down-regulated miR-448 inhibited apoptosis of nerve cells and improved neurological function by up-regulating SIRT1, which contributes to relieving SCII.

Stability of two anterior fixations for three-column injury in the lower cervical spine: biomechanical evaluation of anterior pedicle screw-plate fixation.

Objectives This study aimed to evaluate the stability of anterior pedicle screw-plate (APSP) fixation and anterior vertebral body screw-plate (AVBSP) fixation for three-column injury in the lower cervical spine. Methods Six fresh-frozen human cadaveric specimens of the lower cervical spine were prepared. After measurement of the range of motion (ROM) in the intact state, the specimens were prepared as three-column injury models. The models were stabilized by AVBSP or APSP fixation. The ROM of the models in the two states was measured. The ROM in the two states was compared. Results The ROM of the intact state in all directions was significantly smaller than that of the AVBSP state and significantly larger than that of the APSP state. The ROM of the AVBSP state in all directions was significantly larger than that of the APSP state. Conclusions This study shows that APSP fixation can provide sufficient stability for three-column injury in the lower cervical spine. The primary stability of our models using APSP fixation is superior to that of AVBSP fixation. These results suggest that APSP can be used for three-column injury in the lower cervical spine.

Down-regulated miR-448 relieves spinal cord ischemia/reperfusion injury by up-regulating SIRT1

MicroRNAs play a crucial role in the progression of spinal cord ischemia/reperfusion injury (SCII). The role of miR-448 and SIRT1 in SCII was investigated in this study, to provide further insights into prevention and improvement of this disorder. In this study, expressions of miR-448 and SIRT1 protein were determined by qRT-PCR and western blot, respectively. Flow cytometry was used to analyze cell apoptosis. The endogenous expression of genes was modulated by recombinant plasmids and cell transfection. Dual-luciferase reporter assay was performed to determine the interaction between miR-448 and SIRT1. The Basso, Beattie, and Bresnahan score was used to measure the hind-limb function of rat. The spinal cord ischemia reperfusion injury model of adult rats was developed by abdominal aorta clamping, and the nerve function evaluation was completed by motor deficit index score. In SCII tissues and cells treated with hypoxia, miR-448 was up-regulated while SIRT1 was down-regulated. Hypoxia treatment reduced the expression of SIRT1 through up-regulating miR-448 in nerve cells. Up-regulation of miR-448 induced by hypoxia promoted apoptosis of nerve cells through down-regulating SIRT1. Down-regulated miR-448 improved neurological function and hind-limb motor function of rats with SCII by up-regulating SIRT1. Down-regulated miR-448 inhibited apoptosis of nerve cells and improved neurological function by up-regulating SIRT1, which contributes to relieving SCII.

[Percutaneous endoscopic lumbar discectomy combined with epidural injection for prolapsed lumbar disc herniation].

OBJECTIVE: To assess the effect of percutaneous endoscopic lumbar discectomy (PELD) combined with epidural injection for prolapsed lumbar disc herniation(PLDH). METHODS: In this prospective randomized controlled study, the clinical data of 126 patients who had undergone a PELD because of a single-level PLDH from March 2014 to June 2015 were analyzed. There were 67 males and 59 females, ranging in age from 17 to 75 years old with an average of(41.0±13.5) years old, 9 cases were L3,4, 76 cases were L4,5 and 41 cases were L5S1. According to the random number table, the patients were randomized into two groups, with 63 patients in each group. Patients in group 1 were injected normal saline after PLED, patients in group 2 were subjected to an epidural injection of Diprospan, Lidocaine and Mecobalamine after PLED. All the patients were followed up from 6 to 20 months with the mean of 12.4 months. Complications, the postoperative hospital stay, the period of return to work, visual analogue scale (VAS) and Japanese Orthopedic Association (JOA) score were compared between two groups, and clinical outcomes were evaluated according to modified MacNab criteria. RESULTS: All the operations were successful, and no complications were found. The mean postoperative hospital stay and the period of return to work in group 1 were (4.61±1.25) days and (4.31±0.47) weeks, respectively, and in group 2 were (2.53±0.69) days and (3.14±0.52) weeks, there was significant differences between two groups(P=0.000). Postoperative VAS and JOA scores in two groups were obviously improved (P=0.000). At 1 day, 1 week, 1 month after operation, VAS, JOA scores in group 2 were better than that of group 1(P=0.000), and after 6 months, there was no significant difference between two groups(P>0.05). According to the modified MacNab criteria, 39 cases got excellent results, 21 good, 3 fair in group 1, and which in group 2 were 41, 20, 2, respectively, there was no significant difference between two groups(P=0.087). CONCLUSIONS: PELD is an mini-invasive technique for PLDH, it can fleetly reduce pain and improve function. And combination with epidural injection has the advantages of pain releasing and function improving in the short-term postoperative period, and it can decrease postoperative hospital stay and time of returning to work, and it is a safe and effective method.