[Clinical study of lumbar stability after unilateral biportal endoscopy in the treatment of degenerative lumbar diseases].

Objectives: To investigate the clinical efficacy of unilateral biportal endoscopy (UBE) in the treatment of degenerative lumbar disease (DLD) and its impact on postoperative lumbar stability. Methods: This is a retrospective case series study. A total of 109 cases of DLD treated with UBE in the Department of Orthopaedic, Beijing Chaoyang Hospital Affiliated to Capital Medical University from July 2020 to June 2022 were analyzed retrospectively. There were 47 males and 62 females, aged (53.3±8.2) years (range: 21 to 80 years). The surgical segments were single segment in 80 cases, two segments in 25 cases, and three segments in 4 cases. The low back pain and leg pain of visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score and Oswestry disability index (ODI) were evaluated before and after operation. The modified MacNab criteria were used for evaluation of the clinical consequences. Postoperative three-dimensional lumbar CT was performed to observe the preservation of the facet joints and the angle of the medial surface of the facetectomy(ß angle). At 12 months after surgery, X ray of the flexion and extension lumbar spine were reviewed. The comparison and analysis of the data were conducted using paired sample t tests or generalized estimation equations. Results: All 109 patients underwent operative procedures successfully. The operation time was (94.5±37.1) minutes (range:56 to 245 minutes), the times of X ray was 6.8±4.0 (range:4 to 16 times), and the days of hospitalization was (5.3±3.7) days (range:4 to 14 days). Complications included dural tears in 4 cases, transient lower limb numbness in 4 cases, epidural hematoma in 2 case. The follow-up time was (19.6±7.2) months (range:12 to 36 months). The postoperative low back pain VAS, leg pain VAS, JOA score and ODI were significantly improved(all P<0.05). According to the modified MacNab criteria, the excellent and good rate was 88.99%(97/109) at 12 months after surgery. One case underwent revision surgery because of recurrent lumbar disc herniation. In term of radiographic evaluation, the area of the surgical side facet joints after UBE surgery was reserved more than 60%. The ß angle was less than 90° in all patients. After 12 months of surgery, there was no surgical segment instability or spondylolisthesis by the X-ray of the flexion and extension lumbar spine. Conclusion: UBE can achieve satisfactory clinical efficacy in the treatment of DLD, and maintain the stability of the lumbar spine.

LINC00662 promotes glycolysis and cell survival by regulating miR- 375/HIF-1α axis in ovarian cancer.

Ovarian cancer (OC) is one of the most common gynecological malignancies, with the highest mortality rate in women worldwide. LINC00662, a long non-coding RNA (lncRNA), was shown to play a vital role in many malignancies, while little is known about its role in OC. Firstly, our study determined the expression of LINC00662 in OC tissues and cells. Upregulation or downregulation of LINC00662 were performed in OC cells to explore its effects on cell proliferation and glycolysis of OC. The interaction between LINC00662 and miR-375 was verified using luciferase assays and RNA immunoprecipitation. Results showed that LINC00662 was highly expressed in OC tissues and cells, and patients with increased expression of LINC00662 were associated with shorter overall survival. Furthermore, functional assays proved that LINC00662 was essential for OC cell proliferation and glycolysis. Subsequently, our study further revealed that LINC00662 acted as a competitive RNA and it could modulate the expression of HIF-1α through directly binding with miR- 375. Collectively, upregulation of LINC00662 in ovarian cancer tissues is closely correlated to poor survival. LINC00662 might regulate HIF-1α expression via miR-375. These findings suggested that LINC00662 has the potential to be explored as a diagnostic biomarker for OC.

[Comparison of cortical bone trajectory screw fixation and pedicle screw fixation in posterior lumbar fusion].

Objective: To evaluate the efficacy and safety of cortical screw fixation in posterior lumbar spine fixation with cortical bone trajectory (CBT) fixation or pedicle screw (PS) fixation in posterior lumbar fusion. Methods: It was a prospective study and CBT or PS for the treatment of lumbar disease from August 2015 to August 2017 in Beijing Chaoyang Hospital were analyzed. There were 53 males and 51 females, aged 56-78 years (mean age, (67±5) years). The patient's gender, age, operative time, intraoperative blood loss, postoperative bleeding, postoperative hospital stay, and postoperative patient satisfaction were collected. The Oswestry disability index (ODI) and visual analogue scale (VAS) of back pain were used to evaluate preoperative and half-year, one-year and two-year postoperative function and quality of life. Complications such as wound infection, cage displacement, screw extraction and fixation fracture were compared between the two groups. The data of normal distribution were compared with Student t test between the two groups. Results: There was no significant difference in the operation time between the CBT group (n=50) and the PS group (n=54) ((223±17) min vs (221±16) min, t=0.74, P=0.46). The intraoperative blood loss and wound drainage volume were significantly lower in the CBT group than those in the PS screw group (t=-24.20, -57.62, both P<0.05). The average length of hospital stay in the CBT group was significantly shorter than that in the PS group (t=-7.65, P=0.00). Patients with CBT screws had better postoperative satisfaction than patients in PS group (91±6 vs 86±7, t=3.89, P=0.00). The ODI score in the CBT group was significantly lower than that in the PD screw group half a year after the operation (3.9±1.9 vs 5.8±3.1, t=-3.66, P=0.00). The VAS and ODI scores in the CBT group were significantly lower than those in the PS group 1 year after the surgery (t=-3.03, -4.09, both P<0.05). There was no significant differences in wound infection, cage displacement, screw extraction and fixation fracture between the two groups. Conclusion: CBT screw technique is minimally invasive, with short operation time, less intraoperative blood loss, rapid postoperative recovery and low complications. It can be effectively used in posterior lumbar cone fusion.

Increasing the thermostability of D-xylose isomerase by introduction of a proline into the turn of a random coil.

Thermostability can be increased by introducing prolines at suitable sites in target proteins. Two single (G138P, G247D) mutants and one double (G138P/G247D) mutant of xylose isomerase from Streptomyces diastaticus No.7, strain M1033 have been constructed by site-directed mutagenesis. With respect to the wild-type enzyme, G138P showed about a 100% increase in thermostability, and G247D showed an increased catalytic activity. Significantly, the double mutant, G138P/G247D displayed even higher activity than G247D and better heat stability than G138P. Its half life was about 2.5-fold greater than the wild-type enzyme, using xylose as a substrate. Molecular modelling suggested that the introduction of a proline residue in the turn of a random coil may cause the surrounding conformation to be tightened by reducing the backbone flexibility. The change in thermostability can, therefore, be explained based on changes in the molecular rigidity. Furthermore, the improvements in the properties of the double mutant indicated that the advantages of two single mutants can be combined effectively.

Connection ensemble model of local neural circuits.

A connection ensemble model (CEM) of local neural circuits in central nervous system (CNS) is proposed in this work. Neuronal interactions are investigated at two levels, i.e. the synaptic connection between single neurons and the macro-connections between different neuronal groups. The efficacy of macro-connection is quantitatively determined by the efficacies of constituent synapses, and is asymptotically stable. This model provides a reasonable description for the functional invariance of local neural circuits with structural diversities, which is a widely observed fact in neurobiology. It is expected that the works in CEM model would enrich the current research in neural dynamics.