Weixu Li

Response of osteogenic sarcoma to neoadjuvant therapy: evaluated by 18F-FDG-PET

ObjectiveThe aim of this study was to evaluate the potential role of F-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in assessing the chemotherapy response of osteosarcoma when compared with histologically assessed tumor necrosis.MethodsFifteen patients were examined with whole-body FDG-PET prior to and following neoadjuvant therapy. The maximum standard uptake value (SUVmax) of tumor and tumor to background ratio (TBR) prior to and following chemotherapy was used for semiquantitative PET imaging analysis. The SUVmax of prechemotherapy and post-chemotherapy was recorded as SUV1 and SUV2. TBR1 and TBR2 represented prechemotherapy and post-chemotherapy TBR. TBR was calculated by drawing an identical region of interest over the tumor and the contralateral normal limb or pelvis. Tumor necrosis was classified according to Salzer-Kuntschik’s criteria.ResultsEight patients with more than 90% tumor necrosis were classified as showing good responses and seven patients with less than 90% tumor necrosis as showing poor responses. SUV2/SUV1, TBR2/TBR1, and TBR2 were significantly correlated with the tumor necrosis degree (P < 0.01, P < 0.001, P < 0.001). TBR2/TBR1 were below 0.46 in all the patients with favorable responses, and higher than 0.49 in all the patients with unfavorable responses. However, it was difficult to distinguish good responses from poor responses by SUV2/SUV1.ConclusionsFDG-PET is a promising tool to assess the chemotherapy response of osteosarcoma noninvasively. The TBR was better than SUVmax in evaluating the chemotherapy response in this study.

Highly efficient release of simvastatin from simvastatin‑loaded calcium sulphate scaffolds enhances segmental bone regeneration in rabbits

A number of clinical and experimental studies have investigated the effect of simvastatin on bone regeneration. In the present study, the release of simvastatin from simvastatin-loaded calcium sulphate (CS) scaffolds and the effect of these scaffolds on osteogenic differentiation of bone marrow-derived mesenchymal stem cells (MSCs) in vitro and the effect of simvastatin locally applied from CS scaffolds on bone regeneration were investigated. A total of 26 complete 1.2-cm bone defects were created in the ulna of rabbits, which were treated with CS, simvastatin-loaded CS or recombinant human bone morphogenetic protein 2 (rhBMP)-2-loaded CS. Simvastatin was highly efficiently released from simvastatin-loaded CS at the onset and stable release was maintained. Alkaline phosphatase was highly expressed in the MSCs co-cultured with simvastatin/CS scaffolds for 7 and 14 days. The defects treated with rhBMP-2-loaded CS and simvastatin-loaded CS showed significantly higher X-ray analysis scores and a larger amount of bone formation as determined by histology compared with the CS group (P<0.05). No significant differences in the X-ray score and bone formation were observed between groups with rhBMP-2-loaded CS and simvastatin-loaded CS (P>0.05). Simvastatin is capable of promoting osteogenic differentiation of MSCs in vitro and stimulating bone regeneration when locally released from CS scaffolds into bone defects. The beneficial effect of simvastatin was similar to that of rhBMP-2. In conclusion, the present study suggested that the simvastatin-loaded CS scaffolds may have great potential in bone tissue engineering.

Intraosseous lipoma of the pelvis and spine: two cases reports

Case one: A 53-year-old woman presented with pain in her right hip for one week after minor trauma. No swelling, tenderness or limitation of movement was present. Plain radiographs showed a well defined, expansile, radiolucent lesion involving the right acetabulum. The lesion was surrounded by sclerosis and contained osseous septations (Fig. 1). Computed tomography (CT) showed a hypodense lesion with expanded cortex (Fig. 2). Magnetic resonance imaging (MRI) showed high signal intensity on T1 weighted images, similar to subcutaneous adipose tissue (Fig. 3), and decreased signal intensity on short-T inversion recovery (STIR) images. Surgery consisting of curettage and bone grafting was performed. At surgery, the lesion was grossly yellow in color and fatty in consistency. Histologically, mature lipocytes and fine fibrovascular septa were noted (Fig. 4). Case two: A 37-year-old woman was sent to our hospital because of a swelling in her neck for 6 months. No pain or limitation of neck movement was present. Plain radiographs showed a clearly defined radiolucent osseous expansile tumor originating in the spinous processes of the third cervical vertebrae (Fig. 5). CT showed no apparent periosteal reaction, no evidence of soft tissue tumor, and multilocular change within the bone tumor (Fig. 6). MRI showed that the spinous processes and the lamina of the third cervical vertebra were damaged. The tumor

p53 siRNA inhibits apoptosis of U2OS cells treated with azurin.

The bacterial redox protein azurin selectively induces apoptosis in human osteosarcoma U2OS cells. We constructed a p53 siRNA to test the role that p53 plays in the apoptosis-inducing role of azurin in U2OS cells. Cells treated with p53 siRNA and azurin showed more viable cells, a lower apoptosis rate, lower caspase-3 activity, and up-regulation of bcl-2, downregulation of bax compared to cells treated with negative siRNA and azurin. Cells treated with negative siRNA and azurin yielded positive TUNEL dying, whereas cells treated with p53 siRNA and azurin yielded few positive cells. These results suggested that p53 siRNA was capable of inhibi-ting the apoptosis induced by azurin 2 days after treatment with p53 siRNA and azurin. Azurin may induce apoptosis through combination with p53. The decrease in p53 protein levels did not inhibit cell apoptosis rates, but rather increased these rates in U2OS osteosarcoma cells 3 days after treatment with p53 siRNA. Since U2OS cells are p53 wild-type cancer cells, p53 potentially acts as an oncogene in U2OS osteosarcoma cells. Treatment with azurin may transform the function of p53 from inhibiting to inducing apoptosis.

Upshifting the Ipsilateral Proximal Femur May Provide Satisfactory Reconstruction of Periacetabular Pelvic Bone Defects After Tumor Resection

Background Pelvic ring reconstruction after resection of pelvic malignancies or aggressive benign tumors remains challenging, especially when the tumor invades periacetabular bone, resulting in a Type II resection as classified by Enneking and Dunham (removal of part or all of the acetabulum). Although numerous treatment approaches are in use, none is clearly superior to the others. An alternative involving use of the ipsilateral proximal femur as an autograft has not been well characterized, so we present our preliminary experience with this approach. Questions/purposes (1) What were the oncologic outcomes after using an ipsilateral proximal femur autograft for reconstruction after Type II pelvic resection in a small series of patients who underwent this reconstructive approach? (2) What were the Musculoskeletal Tumor Society (MSTS) scores after this reconstruction? (3) What complications were observed? Methods Between October 2006 and May 2016, we treated 67 patients with Type II malignant or aggressive benign tumors of the ilium. Of those, we used an ipsilateral proximal femur and a prosthesis as a reconstruction method for 11 patients with pelvic tumors. In general, we performed this approach in young or middle-aged patients with primary malignant or aggressive benign tumors involving pelvic area II and in whom the tumor did not invade the hip. The method used for resection of pelvic tumors included osteotomy of the femoral shaft, harvesting the proximal femur as a graft. The length of the femoral graft was determined by the extent of the pelvic defect. The proper placement was selected after a comparison of the proximal femur and the pelvic defect. A curved reconstruction plate and cancellous bone screws were used for pelvic fixation. The operative duration and total blood loss were recorded. Of the 11 patients who underwent this approach, all but one had at least 2 years of followup unless death occurred earlier, and all but one have been seen within the last year for evaluation. Functional outcomes were assessed using the MSTS scoring system. Local recurrence, metastases, and deaths were recorded as were complications including infection, bone nonunion, mechanical failure and sciatic nerve palsy. Results The followup was a mean of 37 months (range, 13-96 months). One patient was lost to followup. Three patients died of disease owing to local recurrence or lung metastasis. The other seven patients lived without evidence of tumor. The main complications included mechanical failure in two patients, nonunion in one patient, infection in two patients, and sciatic nerve palsy in one patient. The median MSTS function score was 70% (21 of 30 points; range, 11-25 points). Conclusions Our preliminary results show that this technique of using the ipsilateral proximal femur may be an alternative method for reconstruction of pelvic bone defects after tumor resection. Even with this short followup, complications were common, but short-term function appears to be comparable to studies of other options. Longer term followup with more patients is necessary to confirm our results. Level of Evidence: Level IV, therapeutic study.