ObjectiveTo review the biomaterial and clinical prospects of annulus fibrosus tissue engineering. MethodsThe recent literature concerning annulus fibrosus tissue engineering, including cell source, bioactive molecules, and biomaterial was extensively reviewed and summarized. ResultsMesenchymal stem cells (MSCs) is an ideal seed cells. When annulus fibrosus cells and MSCs in the ratio of 2:1 are cultured, it shows the closest mRNA expression levels of annulus fibrosus-related markers. Bioactive molecules can be divided into 4 types:growth factors, morphogens, catabolic enzyme inhibitors, and intracellular regulators. They play an active role in promoting the synthesis of extracellular matrix, and maintaining intervertebral disc homeostasis and a balance between anabolic- and catabolic process in the disc. Based on the source, biological materials can be divided into natural materials, synthetic materials, and composite materials. The mechanical properties of the annulus fibrosus is an important basis for material design. Up to now, none of these scaffold materials is accepted as the most suitable one. The selection of scaffold materials is still to be further studied. The development of novel composite biomaterials is a trend. ConclusionThe annulus fibrosus tissue engineering for the anulus fibrosus regeneration and repair will bring very broad prospects for clinical application in future.
ObjectiveTo investigate the feasibil ity and short-term effectiveness of percutaneous endoscopic spine surgery for treatment of lumbar disc herniation with posterior ring apophysis separation. MethodsBetween July 2008 and January 2013, 57 patients with lumbar disc herniation and posterior ring apophysis separation were treated. There were 39 males and 18 females, aged from 13 to 46 years (mean, 26.7 years). Of 57 cases, 29 had a clear trauma history. All patients had single segmental unilateral lumbar disc herniation, and the location was at L4, 5 in 22 cases and at L5, S1 in 35 cases; there were 25 cases of lateral bone fragments and 32 cases of central cortical and cancellous fragments. While fracture located at posterior inferior edge of the vertebrae at L4 level in 9 cases and at L5 level in 8 cases, at posterior superior edge at L5 level in 13 cases and in S1 level in 27 cases. Percutaneous endoscopic surgeries were performed via interlaminar or transforaminal approach from unilaterally symptomatic side for discectomy of lumbar disc herniation and partial or complete resection of free bone fragments. ResultsAccurate positioning was obtained in all patients during operation, and no complication of nerve root injury, hematoma formation, or dural tear occurred. The operation time was 20-85 minutes; the intraoperative fluoroscopy times were 2-15 times, and the blood loss was 3-10 mL. Postoperative radiographic examination showed that bone fragment was not removed in 16 cases, was partly removed in 32 cases, and was completely removed in 9 cases. Disc was completely removed. All patients were followed up 10-64 months (median, 16 months). According to modified Macnab criteria for the evaluation of effectiveness, the results were excellent in 48 cases, good in 6 cases, and fair in 3 cases, and the excellent and good rate was 94.7%. ConclusionPercutaneous endoscopic spine surgery through unilaterally symptomatic approach has advantages of small tissue damage and lumbar structure damage, less bleeding, and shorter recovery time. It has a good short-term effectiveness, but long-term effectiveness need further follow-up.
ObjectiveTo investigate whether miR-93-5p suppresses osteogenic differentiation of mouse mesenchymal stem cells (C3H10T1/2) by targeting Smad5, a predicted target in silicon. MethodsSmad5 3'-UTRluciferase vector (pmiR-RB-REPORTTM) was constructed and dual-luciferase reporter gene assay was employed to examine the effect of miR-93-5p on Smad5 3'-UTR-luciferase activity to identify whether Smad5 was the target gene of miR-93-5p. miR-93-5p mimics (group M), miR-93-5p inhibitor (group In), miR-93-5p mimics negative control (group MC), and miR-93-5p inhibitor negative control (group InC) were transfected into the C3H10T1/2 cells, respectively, and followed by induction of osteogenic differentiation. After 48 hours, the real-time fluorescent quantitative PCR (qRTPCR) and Western blot assays were performed to detect the relative expressions of Smad5 mRNA and protein. At 14 days, to realize the regulation role of miR-93-5p in osteogenic differentiation, the extracellular calcium deposition during the osteogenesis of C3H10T1/2 cells was tested by Alizarin red staining. ResultsDual-luciferase reporter gene assay showed that miR-93-5p could combine with Smad5 mRNA 3'-UTR specificity, and inhibited its luciferase activity (P<0.05). After 48 hours, no significant difference was shown in the relative expression of Smad5 mRNA between group M and group MC as well as between group In and group InC by qRT-PCR assay (P>0.05); however, the results of Western blot assay showed that the relative expression of Smad5 protein was significantly decreased in group M and increased in group In when compared with groups MC and InC (P<0.05). At 14 days after osteogenic induction, Alizarin red staining showed that the extracellular calcium deposition of group M was obviously less than that of group MC, and it was obviously more in group In than in group InC. ConclusionSmad5 may be the target gene of miR-93-5p. And miR-93-5p can suppress osteogenic differentiation of C3H10T1/2 cells by directly targeting Smad5.
ObjectiveTo summarize the experience in management of occult cerebrospinal fluid leakage (CSFL) in posterior thoracolumbar surgeries, and to explore the best drainage duration, as well as to analyse the ways to reduce the risk of CSFL. MethodsA retrospective analysis was made on the clinical data of 26 patients with occult CSFL in posterior thoracolumbar surgeries between January 2011 and January 2013. There were 15 males and 11 females, with the average age of 48.7 years (range, 36-59 years). Headache occurred in 19 cases, and 5 cases had nausea with 3 cases also having vomiting after operation. Drainage tube unobstructed and no CSFL from the skin incision were observed in 23 cases at the postoperative 2nd day, and the drainage pipe clamp test was performed at the 3rd day. Twenty-one patients had no CSFL and were given extubation; 2 cases having CSFL were given extubation after conservative treatments for 10 days. Three patients had CSFL with ineffective conservative treatments at the postoperative 2nd day, then received reoperation, incision suture, and drainage. At the postoperative 3rd day, if no CSFL was observed, these patients were given extubation and stayed in bed for 3-5 days. ResultsAll incisions healed and the healing time was 7-15 days (mean, 8 days). No incision infection, persistent CSFL, and other complications occurred. After extubation, headache, nausea, vomiting, and other symptoms were alleviated immediately. All patients were followed up 12-24 months (mean, 16 months). MRI at the postoperative 6th month showed no subcutaneous epidural pseudocyst. ConclusionThe quality of suturing is the key factor to prevent occult CSFL in posterior thoracolumbar surgery. Under the premise of good suture quality, extubation can be given at the postoperative 3rd day. Before extubation, the drainage pipe clamp test can be performed to make sure no CSFL and to reduce the risk of CSFL from the surgical incision after extubation.