Inhibitory effect and significance of rapamycin on the mammalian target of rapamycin signaling pathway in osteosarcoma stem cells and osteosarcoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To observe the effect of rapamycin on the MG-63 osteosarcoma cells (OC), osteosarcoma stem cells (OSC) and on mTOR signaling pathway, and explore the feasibility of rapamycin as a novel therapeutic measure in osteosarcoma chemotherapy regimens.</p><p><b>METHODS</b>OC and OSC were cultured in vitro. Immunofluorescence assay was used to detect the expression of Nanog and Oct4 in OC and OSC. OC and OSC were treated with rapamycin in concentrations of 0, 20, 50 and 100 nmol/L. Semi-quantitative PCR and RT-PCR were used to detect the mTOR mRNA and CCK-8 assay was used to detect cell proliferation, and the cell morphology was observed under an inverted microscope.</p><p><b>RESULTS</b>The cores of MG-63 cellular spheres exhibited embryonic stem cell characteristics such as Nanog and Oct4 expession. The mTOR pathway was activated in the OSC and the expression of mTOR mRNA was higher in OSC (0.761 ± 0.080) than that in OS (0.406 ± 0.090, P < 0.05) by semi-quantitative PCR. RT-PCR showed that the expression of mTOR mRNA was lower in OSCs treated with 100 nmol/L rapamycin (0.961 ± 0.060) than that with 0 nmol/L rapamycin (1.654 ± 0.246, P < 0.05). Cell counting kit-8 (CCK-8) assay showed that the proliferation of OC treated with 20, 50 and 100 nmol/L rapamycin was significantly inhibited, compared with that with 0 nmol/L rapamycin (P < 0.05). Compared with 0 nmol/L rapamycin, the proliferation of OSC treated with 20 and 50 nmol/L rapamycin was not significantly inhibited (P > 0.05), but that with 100 nmol/L rapamycin was significantly inhibited (P < 0.05). The invert microscopic observation revealed that rapamycin inhibited the formation of OSC spheres.</p><p><b>CONCLUSIONS</b>Rapamycin can effectively inhibit cell proliferation and the ability of sphere formation of OSCs. It will provide a basis for a novel therapeutic approach in osteosarcoma chemotherapy regimens.</p>

Treatment of ipsilateral femoral neck and shaft fractures / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the clinical characteristics, treatment options and causes of misdiagnosis of ipsilateral femoral neck and shaft fractures.</p><p><b>METHODS</b>Among 20 patients with ipsilateral femoral neck and shaft fractures, 19 were treated operatively and 1 was treated conservatively. Sixteen cases of femoral shaft fractures were treated by open reduction and internal fixation with compressive plate, and 2 cases were treated with interlocking intramedullary nailing. Eighteen femoral neck fractures were treated with cannulated screws. Another patient was treated with proximal femoral nail to fix both the neck and shaft. Delayed diagnosis for femoral neck fractures occurred in 2 cases preoperatively.</p><p><b>RESULTS</b>A total of 19 patients were followed up. The follow up period ranged from 5 to 48 months with an average of 15 months. All the fractures were healed.</p><p><b>CONCLUSION</b>For case of femoral shaft fracture caused by high energy injury, an AP pelvic film should be routinely taken. Once the femoral neck fracture is recognized, operative reduction and fixation should be performed in time. Femoral neck and shaft fractures should be fixed separately.</p>

Treatment of nonunions of humeral fractures with interlocking intramedullary nailing / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To introduce the experience of treating nonunions of humeral fractures with interlocking intramedullary nailing.</p><p><b>METHODS</b>Twelve patients with humeral nonunions were treated with interlocking intramedullary nailing. The time interval between trauma and surgery was 10.5 months on average. Open reduction with anterograde approach was performed. Axial compression was specially applied to the fracture site with humeral nail holder after insertion of distal locked screws. Iliac bone grafting was added.</p><p><b>RESULTS</b>The average follow-up period was 21 months (ranging 9-51 months). All patients achieved osseous union 5.8 months after treatment on average. Eleven patients had good functions of the shoulder joints and the upper extremities. No patient experienced any permanent neurological deficit. Refracture of the original ununited region occurred in one patient after removal of the internal fixator one year later, but union was achieved after closed re-intramedullary nailing fixation.</p><p><b>CONCLUSION</b>Humeral interlocking intramedullary nailing is an effective alternative treatment for humeral nonunion.</p>