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PurposesThe objective of this study was to investigate the role of stromal cell-derived factor-1 (SDF-1) and its receptor, CXCR4, on bone healing and whether SDF-1 contributes to accelerating bone repair in traumatic brain injury (TBI)/fracture model.Materials and MethodsReal-time polymerase chain reaction and immunohistochemical analysis were used to detect the expression of SDF-1 during the repair of femoral bone in TBI/fracture model. The TBI/fracture model was treated with anti–SDF-1 neutralizing antibody or AMD3100, an antagonist for CXCR4, and evaluated by histomorphometry. In vitro and in vivo migration assays were used to evaluate the functional effect of SDF-1 on primary mesenchymal stem cells.ResultsThe expression of SDF1 and CXCR4 messenger RNA was increased during the bone healing in TBI/fracture model but was less increased in fracture only model. High expression of SDF-1 protein was observed in the surrounding tissue of the damaged bone. Treated with anti–SDF-1 antibody or AMD3100 could inhibit new bone formation. SDF-1 increased mesenchymal stem cell chemotaxis in vitro in a dose-dependent manner. The in vivo migration study demonstrated that mesenchymal stem cells recruited by SDF-1 participate in endochondral bone repair.ConclusionThe SDF-1/CXCR4 axis plays a crucial role in the accelerating fracture healing under the condition of TBI and contributes to endochondral bone repair.

Telomerase activation represents an early step in carcinogenesis. Increased telomerase activity in cervical cancer suggests a potential target for the development of novel therapeutic drugs. The aim of this study is to investigate the impact of telomerase activity on the biological features of HeLa cells and the possible mechanisms of enhanced apoptosis rate induced by sodium butyrate after telomerase inhibition. We introduced vectors encoding dominate negative (DN)-hTERT, wild-type (WT)-hTERT, or a control vector expressing only a drug-resistance marker into HeLa cells. Thus we assessed the biological effects of telomerase activity on telomere length, cell proliferation, chemosensitivity and radiosensitivity. In order to understand the mechanisms in which DN-hTERT enhances the apoptosis induced by sodium butyrate, we detected the release status of cytochrome c and apoptosis inducing factor (AIF) from mitochondria. Ectopic expression of DN-hTERT resulted in inhibition of telomerase activity, reduction of telomere length, decreased colony formation ability, and loss of tumorigenicity in nude mice. Moreover, DN-hTERT transfected HeLa cells with shortened telomeres were more susceptible to multiple chemotherapeutic agents and radiation. WT-hTERT transfected HeLa cells with longer telomeres exhibited resistance to radiation and chemotherapeutic agents. Our data demonstrate that elevated release level of cytochrome c and AIF from mitochondria might contribute to the enhanced apoptosis in DN-hTERT transfected HeLa cells after treatment with sodium butyrate. Inhibition of telomerase might serve as a promising adjunctive therapy combined with conventional therapy in cervical cancer.

Our results suggest an increased risk of shorter alleles compared with normal alleles and longer alleles against lumbar disc degeneration among populations especially among Asian descent. Such association may not be statistically significant in European populations.

Purpose The clinical outcomes of using a cortical screw (CS) for lumbar interbody fusion were evaluated by comparison with conventional pedicle screw (PS) fixation. Methods All of the comparative studies published in the PubMed, Cochrane Library, MEDLINE, Web of Science, and EMBASE databases recently as 18 March 2019, were included. All outcomes were analyzed by using Review Manager 5.3. Results Twelve studies were included with a total of 835 patients, and two of the studies were randomized controlled trials. The outcomes of the meta-analysis indicated that the use of CS fixation for lumbar interbody fusion was better than conventional PS fixation in regard to operating time ( p = 0.02), intraoperative blood loss ( p < 0.00001), length of stay ( p = 0.02), incidence of complications ( p = 0.02), adjacent segmental disease (ASD) incidence ( p = 0.03), and Oswestry Disability Index (ODI) ( p = 0.03). However, there were no statistically significant differences in the back and leg pain visual analog scale (VAS), Japanese Orthopaedic Association (JOA) scale, and intervertebral fusion rate (all p > 0.05) between the CS fixation group and the PS fixation group. Conclusions Based on this systematic review and meta-analysis, our outcomes indicated that both CS and conventional PS can result in good postoperative outcomes in lumbar interbody fusion. No significant differences were found in the back and leg pain VAS, JOA scale, and intervertebral fusion rate. However, CS fixation is superior to PS fixation in the following measures: operating time, intraoperative blood loss, length of stay, incidence of complications, ASD incidence, and ODI. Trial registration PROSPERO registration number is CRD 42019132226 .