Bmi deficiency causes oxidative stress and intervertebral disc degeneration which can be alleviated by antioxidant treatment.

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 1ß 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.

A meta-analysis on anterior cruciate ligament reconstruction: Is modified transtibial technique inferior to independent drilling techniques?

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.

Synergistic effects of high dietary calcium and exogenous parathyroid hormone in promoting osteoblastic bone formation in mice.

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 (10⁻8 M) 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.

A comparison of posterior lumbar interbody fusion and transforaminal lumbar interbody fusion: a literature review and meta-analysis.

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 <0.00001), and TLIF reduced the rate of durotomy (P = 0.01). No statistical difference was found between the two groups with regard to clinical satisfaction (P = 0.54), blood loss (P = 0.14), vertebral root injury (P = 0.08), graft malposition (P = 0.06), infection (P = 0.36), or rate of radiographic fusion (P = 0.27). The evidence indicated that PLIF required longer operative time (P = 0.03). CONCLUSIONS: The evidence indicated that TLIF could reduce the complication rate and durotomy. Neither TLIP nor PLIF was found superior in terms of clinical satisfaction or radiographic fusion rate. PLIF might result in longer time in surgery.

[Effect of 1,25-dihydroxyvitamin D3 on posterior transforaminal lumbar interbody fusion in patients with osteoporosis and lumbar disc degenerative disease].

OBJECTIVE: To investigate the role of 1,25-dihydroxyvitamin D3 in the posterior transforaminal lumbar interbody fusion (TLIF) for patients with osteoporosis and lumbar degenerative disease. METHODS: Between November 20ll and October 2012, 44 patients with osteoporosis and lumbar degenerative disease were treated with TLIF and the clinical data were retrospectively analyzed. The patients were divided into 2 groups based on the administration of 1,25-dihydroxyvitamin D3. After TLIF operation, 1,25-dihydroxyvitamin D3 was used in 21 patients (trial group), and was not used in 23 patients (control group). There was no significant difference in gender, age, etiology, affected segment, and disease duration between 2 groups (P > 0.05). Lumbar interbody fusion was observed by X-ray and thin-section CT scan reconstruction of lumbar spine according to Brantigan assessment system at 6 months after operation and last follow-up. Clinical outcome was evaluated by Oswestry disability index (ODI) before and after operation. RESULTS: The patients of 2 groups were followed up 12-27 months (mean, 14.5 months). No fixation loosening or breaking occurred during follow-up. ODI scores in both groups were significantly improved at 6 months after operation and last follow-up (P < 0.05) when compared with preoperative value. Although at preoperation there was no significant difference in ODI score between 2 groups (P > 0.05), ODI score of trial group was significantly lower than that of control group at 6 months after operation and last follow-up (P < 0.05). At 6 months after operation, the interbody fusion rate was 76.19% (16/21) in trial group and 43.48% (10/23) in control group, showing significant difference (χ2 = 3.60, P =0.03); at last follow-up, the fusion rate was 95.24% (20/21) in trial group and 65.22% (15/23) in control group, showing significant difference (χ2 = 4.38, P = 0.02). CONCLUSION: 1,25-dihydroxyvitamin D3 can improve the lumbar interbody fusion rate and general conditions in the patients with osteoporosis and lumbar degenerative disease.