BACKGROUND: Posterior internal fixation and fusion system is a main method for chronic back pain caused by intervertebral disc degeneration, but more postoperative adverse reactions occur. Dynamic stabilization system can reduce adjacent-segment degeneration, and theoretically, repair intervertebral disc degeneration.OBJECTIVE: To investigate the efficacy and safety of K-rod dynamic stabilization system in the repair of lumbar degenerative diseases.METHODS/DESIGN: We conducted a prospective, single-center, self-controlled, clinical trial at the Orthopedic Hospital of Shenyang, China. Sixty-seven patients with lumbar degenerative diseases were enrolled, and treated with K-rod dynamic stabilization system. All patients were followed for 2 years. The primary outcome was the changes in the Oswestry dysfunction index scores at baseline, 3, 6, 12 and 24 months postoperatively. The secondary outcomes were the ratio of height vertebral space to body and lumbar lordotic angle at baseline, 3, 12 and 24 hours postoperatively; the visual analogue scale scores for back pain and morphological changes in the lumbar vertebrae on x-ray preoperatively and 3, 6, 12 and 24 months after surgery; the incidence of adverse reactions at 3, 6, 12 and 24 months postoperatively.This trial has been registered at ClinicalTrials.gov (identifier: NCT03214042). The study protocol has been approved by the Ethics Committee of Orthopedic Hospital of Shenyang. All protocols will be performed in accordance with the Ethical Principles for Medical Research Involving Human Subjects in the Declaration of Helsinki. Written informed consent was provided by each patient after they indicated that they fully understood the treatment plan.DISCUSSION: This trial was designed to investigate the efficacy and safety of K-rod dynamic stabilization system for lumbar degenerative diseases, thus providing reference for its clinical application. Partial results demonstrated that the Oswestry Dysfunction Index and Visual Analogue Scale scores at 24 months postoperatively were significantly improved (P < 0.01), but the ratio of height vertebral space to body and lumbar lordotic angle did not differ significantly at different time points (P > 0.01). These results suggest that K-rod dynamic stabilization system can alleviate pain and improve lumbar function in the patients with lumbar degenerative diseases.

Fifty-two methyl xestospongoate analogues were designed, synthesized and evaluated for the antiproliferative activity. Starting from alkynyl methyl ester and diyne, methyl xestospongoate analogues 4(a-m)-7(a-m)were synthesized by Cadiot-Chodkiewitz coupling and Sonogashira coupling reactions. Their structures were identified by 1H NMR, 13C NMR and HREI-MS. The cytotoxic inhibiton activities in vitro of some compounds were evaluated against human cancer cells A549 and P-388 by a CCK-8 method. Among them, compound 6k exhibited potent cell growth inhibitory activity against A549 and P-388 cancer cells, with IC50 values of 9. 36 and 9. 62 μmol/L, respectively.