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The transcriptional repressor Bmi-1 is involved in cell-cycle regulation and cell senescence, the deficiency of which has been shown to cause oxidative stress. This study investigated whether Bmi-1 deficiency plays a role in promoting disc degeneration and the effect of treatment with antioxidant N-acetylcysteine (NAC) on intervertebral disc degeneration. Bmi-1−/− mice were treated with the antioxidant NAC, supplied in drinking water (Bmi-1−/−+NAC). For in vitro experiments, mouse intervertebral discs were cultured under low oxygen tension and serum-limiting conditions in the presence of tumour necrosis factor α and interleukin 1β in order to mimic degenerative insult. Disc metabolism parameters in these in vitro and in vivo studies were evaluated by histopathological, immunohistochemical and molecular methods. Bmi-1−/− mice showed lower collagen Ⅱ and aggrecan levels and higher collagen Ⅹ levels than wild-type and Bmi-1−/−+NAC mice. Bmi-1−/− mice showed significantly lower superoxide dismutase (SOD)-1, SOD-2, glutathione peroxidase (GPX)-1 and GPX-3 levels than their wild-type littermates and Bmi-1−/−+ NAC mice. Relative to Bmi-1−/− mice, the control and Bmi-1−/−+NAC mice showed significantly lower p16, p21, and p53 levels. These results demonstrate that Bmi-1 plays an important role in attenuating intervertebral disc degeneration in mice by inhibiting oxidative stress and cell apoptosis Refereed/Peer-reviewed

Background. The nerve root sedimentation sign (Sed-sign) is a new diagnostic test for lumbar spinal stenosis. However, few studies have evaluated radiographical outcomes of positive Sed-sign after decompression surgery. The current study aims to evaluate the radiographicaland clinical outcomes of Sed-signafter decompression surgery among a relatively large sample sizeMethods. Patients with positive Sed-sign who underwent transforaminal lumbar interbody fusion (TLIF) surgery were reviewed. Based on postoperative MRI scans, patients with negative or irreversible Sed-sign were assigned to the reversible (R) or irreversible (Ir) groups, respectively. Demographics, radiographic parameters, and health-related quality of life (HRQOL) were evaluated.Results. The R and Ir groups were comprised of 67 and 15 patients, respectively. There were no significant differences between two groups in terms of mean age, sex, postoperative complications as well as mean follow-up time (all P>0.05). After surgery, disc height (DH), foramina height (FH), and segmental lordosis (SL) in both groups were restored. At the latest follow-up, the smallest cross-sectional area (CSA) was significantly increased when compared with preoperatively (P2 was a risk factor for the irreversibility of Sed-sign.Conclusion.TLIF surgery resulted in reversibility of positive Sed-sign for most patients. The irreversibility of Sed-sign was associated with poor clinical outcomes. Independent risk factor for the irreversibility of Sed-sign was CSA less than 131.4 mm2.

This report respectively compared the standard transtibial (sTT) technique to the independent drilling (ID) techniques applied to anterior cruciate ligament (ACL) reconstruction. It also made a comparison between the clinical results of the modified transtibial (mTT) technique and of the ID techniques. Prospective studies on transtibial (TT) and ID techniques for ACL reconstruction were retrieved from several databases and a subgroup analysis was performed to compare the sTT technique with the ID techniques and the mTT with the ID techniques. Furthermore, comparison of the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) subjective and objective evaluations, Lysholm score and Tegner activity scale were conducted. This report included 12 clinical studies that involved 681 patients having received ACL reconstruction. The study results indicated that in comparison between the sTT and ID techniques, the ID techniques outperformed the sTT technique in the IKDC subjective score (P=0.01) and laxity (P=0.0004). However, there was no significant difference in the IKDC objective score (P=0.34), pivot-shift test (P=0.24), Lachman test (P=0.21), Lysholm score (P=0.14) and Tegner activity scale (P=0.66). The comparison between the new mTT technique and the ID techniques suggested no significant difference in the IKDC objective and subjective scores (P=0.86), laxity (P=0.38), pivot-shift test (P=0.66), Lachman test (P=0.10), Lysholm score (P=0.10) and Tegner activity scale (P=0.55). Compared to the sTT technique, the mTT and ID techniques are more suitable for ACL reconstruction because they can present better subjective feelings. Moreover, considering that the TT technique is familiar to surgeons and the mTT technique can bring favorable subjective feelings and objective clinical outcomes, the mTT technique shows greater utilization potential.

In the present study, we investigated whether high dietary Ca and exogenous parathyroid hormone 1–34 fragments (PTH 1–34) have synergistic effects on bone formation in adult mice, and explored the related mechanisms. Adult male mice were fed a normal diet, a high-Ca diet, a PTH-treated diet, or a high-Ca diet combined with subcutaneously injected PTH 1–34 (80 μg/kg per d) for 4 weeks. Bone mineral density, trabecular bone volume, osteoblast number, alkaline phosphatase (ALP)- and type I collagen-positive areas, and the expression levels of osteoblastic bone formation-related genes and proteins were increased significantly in mice fed the high-Ca diet, the PTH-treated diet, and, even more dramatically, the high-Ca diet combined with PTH. Osteoclast number and surface and the ratio of receptor activator for nuclear factor-κB ligand (RANKL):osteoprotegerin (OPG) were decreased in the high-Ca diet treatment group, increased in the PTH treatment group, but not in the combined treatment group. Furthermore, third-passage osteoblasts were treated with high Ca (5 mm), PTH 1–34 (10− 8m) or high Ca combined with PTH 1–34. Osteoblast viability and ALP activity were increased in either the high Ca-treated or PTH-treated cultures and, even more dramatically, in the cultures treated with high Ca plus PTH, with consistent up-regulation of the expression levels of osteoblast proliferation and differentiation-related genes and proteins. These results indicate that dietary Ca and PTH play synergistic roles in promoting osteoblastic bone formation by stimulating osteoblast proliferation and differentiation.

Background We compared the perioperative results and complications associated with PLIF and TLIF, and collected evidence for choosing the better fusion method. Methods A literature survey of the MEDLINE and EMBASE databases identified 7 comparative observational studies that met our inclusion criteria. Checklists by Cowley were used to evaluate the risk of bias of the included studies. A database including patient demographic information, perioperative results, and complications was established. The summary odds ratio and weighed mean difference with 95% confidence interval were calculated with a random-effects model. Results We found that PLIF had a higher complication rate (P