Xuan-Yin Chen

AMD3100 inhibits the migration and differentiation of neural stem cells after spinal cord injury

It was reported that CXCR4 signaling played an important role in the migration and differentiation of endogenous neural stem cells after spinal cord injury (SCI). However, the molecular mechanism of it is still unclear. Here, we established a model of SCI in rats and AMD3100 was used to treat them. The rats were then sacrificed and the injured spinal cord specimens were harvested. Additionally, the neural stem cells (NSCs) line was culture and treated with AMD3100 in vitro. Results showed the locomotor function of SCI rats was worse after treated with AMD3100. And the expression levels of Nestion in neural stem cells and β-tubulin in neuron cells were significantly increased in the injured spinal cord, which can be inhibited by the CXCR4 antagonist of AMD3100. Additionally, the expression of β-catenin and phosphorylase β-catenin protein was significantly down regulated by AMD3100. In vitro, the NSCs proliferation ability was inhibited and the migration was decreased after treated with AMD3100. Also, the expression of Nestion, β-tubulin, β-catenin and phosphorylase β-catenin protein was significantly decreased in AMD3100 group comparing with untreated group. Taken together, this study suggested that AMD3100 could inhibit the migration and differentiation of endogenous neural stem cells in rats with SCI. The mechanism of it maybe that AMD3100 could down regulate of SDF-1/CXCR4 by targeting β-catenin signaling pathway.

Clinical characteristics and risk factors for developing bone metastases in patients with breast cancer

The risk factors for predicting bone metastases in patients with breast cancer are still controversial. Here, a total of 2133 patients with breast cancer, including 327 with bone metastases (15.33%) and 1806 without bone metastases (84.67%) were retrospective reviewed from January 2005 to December 2015. The spine was found to be the most common site for bone metastases, followed by ribs (57.5%), pelvis (54.1%) and sternum (44.3%). The results indicated that axillary lymph node metastases and the concentrations of CA125, CA153, ALP and hemoglobin were the independent risk factors for bone metastases in patients with breast cancer. The receiver operating characteristics (ROC) curves showed that combined axillary lymph node metastases, high CA153 and ALP, with low hemoglobin were the most accurate biomarkers for predicting bone metastases in breast cancer [area under the curve = 0.900], and the sensitivity and specificity for the prediction were 78.5% and 87.8%, respectively. Therefore, breast cancer patients with more axillary lymph node metastases, high serum concentrations of CA125, CA153, ALP and low level of hemoglobin were closely related to bone metastases. Combined axillary lymph node metastases, CA153, ALP with hemoglobin have the highest predictive accuracy for bone metastases in breast cancer.

The incidences and risk factors related to early dysphagia after anterior cervical spine surgery: A prospective study

Dysphagia is a common complication following anterior cervical spine surgery (ACSS). The incidences of dysphagia were variable and controversial. The purpose of this study was to determine the incidence of early dysphagia after ACSS with a new scoring system, and to identify the risk factors of it. A prospective study was carried out and patients who underwent ACSS from March 2014 to August 2014 in our hospital were included in this study. A self-designed dysphagia questionnaire was delivered to all of the patients from the first day to the fifth day after ACSS. Perioperative characteristics of patients were recorded, and incidences and risk factors of dysphagia were analyzed. A total of 104 patients who underwent ACSS were included and incidences of dysphagia from the first to the fifth day after ACSS was 87.5%, 79.81%, 62.14%, 50% and 44.23%, respectively. There was a good correlation between the new dysphagia scoring system and Bazaz scoring system (P < 0.001). Operative time and body mass index (BMI) were the risk factors for dysphagia during the first to the second day postoperatively. However, the dC2-C7angle was the main risk factor for dysphagia from the third to the fifth day after surgery. There were comparatively high incidences of early dysphagia after ACSS, which may be ascribed to operative time, BMI and the dC2-C7 angle.

A comparison of local bone graft with PEEK cage versus iliac bone graft used in anterior cervical discectomy and fusion

OBJECTIVE Anterior cervical discectomy and fusion (ACDF) is a popular procedure for patients with cervical spondylotic myelopathy, but few studies reported the clinical outcomes of cervical local bone graft with a PEEK cage used in it. This retrospective study was performed to compare the clinical and radiological outcomes of using local bone graft with a PEEK cage versus iliac bone graft in ACDF. PATIENTS AND METHODS A total of 60 consecutive patients who underwent ACDF were evaluated from January 2010 to January 2013. Twenty-nine patients received ACDF with a PEEK cage combined with cervical local bone graft (local bone group) and 31 patients received ACDF with autologous tricortical iliac bone graft (iliac bone group). The intraoperative and perioperative complications of both groups were recorded. Preoperative and postoperative radiographs were taken to calculate the ratio of interbody height to the disc height and the interbody bony fusion rate. The Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) were used to estimate postoperative clinical outcomes. RESULTS The mean follow-up duration was 25.0±3.8months in the local bone group and 24.4±3.4months in the iliac bone group (P=0.56). Although there was no significant difference between the two groups in terms of blood loss (P=0.17), the length of surgery was significantly less in the local bone group comparing with that of iliac bone group (P=0.01). Postoperatively, VAS scores were significantly decreased, and JOA scores were improved in both groups. However, no statistically significant differences were found between the two groups at final follow up (P=0.45 and P=0.93). The disc space height and segmental interbody angle at the surgical segment were greater in local bone group than those in the iliac bone group (P<0.001 and P<0.001). The fusion rates were 93.1% in local bone group and 90.3% in the iliac bone group at last follow up (P=0.70). Perioperative complication rates in local bone group and iliac bone groups were 6.8% and 29%, respectively (P=0.04). CONCLUSIONS Based on this study, patients receiving ACDF with local bone graft combined with a PEEK cage had significant shorter operation time, lower perioperative complications rate, and better radiological results comparing with those with an iliac bone graft alone. It seems that the local bone graft with a PEEK cage appears to be a safe alternative to the iliac bone graft for ACDF.

Risk factors for bone metastasis from renal cell cancer

Objective The prognosis for renal cell carcinoma (RCC) is related to a high rate of metastasis, including 30% of bone metastasis. In this study, we investigate the correlation between diverse clinical factors and bone metastases secondary from renal cell cancer (RCC), and to identify potential risk factors for bone metastasis in newly diagnosed patients and those who have already received treatment. Methods The clinical data of 372 patients with RCC were reviewed from January 2000 to August 2016. The correlations between age, gender, histopathologic types, alkaline phosphotase (ALP), CEA, AFP, CA-125, CA-153, CA-199, calcium, hemoglobin (HB) and bone metastases were analyzed. And the risk factors for bone metastases in RCC were identified by multivariate logistic regression analysis. The cutoff value, sensitivity and specificity of the independent correlation factors were calculated by receiver operating characteristic (ROC) curve. Results The bone is the second to the lung as a distant metastasis target site in patients with RCC. Thirty eight individuals were identified with bone metastases. Of these patients, significantly higher levels of ALP, calcium, HB were found than those without bone metastasis (P < 0.05, respectively). No significant differences were detected in CEA, AFP, CA-125, CA-153, CA-199, age, gender and histopathologic types between patients with and without bone metastases (P > 0.05, respectively). Multivariate logistic regression analysis indicated that ALP, calcium and HB were independent risk factors correlated with bone metastasis (P < 0.05, respectively). ROC curves demonstrated these factors had comparable accuracy at predicting bone metastasis (AUC were 0.749, 0.633 and 0.665, respectively). The cutoff values of ALP, calcium and HB were 105.5 U/L, 2.615 mmol/L and 111.5 g/L, respectively. The sensitivities of them were 57.9%, 36.8% and 71.1% for predicting bone metastasis, with specificities of 83.5%, 95.2% and 65.3%, respectively. Conclusion Based on our study, the concentrations of ALP, calcium and HB were potentially risk factors for bone metastasis in patients with RCC. For newly diagnosed patients, if the values of ALP>105.5 U/L, calcium>2.615 mmol/L and HB<111.5 g/L were detected, intensive monitoring and bone scanning are warranted for them.

The effect of screw tunnels on the biomechanical stability of vertebral body after pedicle screws removal: a finite element analysis

PurposePosterior reduction and pedicle screw fixation is a widely used procedure for thoracic and lumbar vertebrae fractures. Usually, the pedicle screws would be removed after the fracture healing and screw tunnels would be left. The aim of this study is to evaluate the effect of screw tunnels on the biomechanical stability of the lumbar vertebral body after pedicle screws removal by finite element analysis (FEA).MethodsFirst, the CT values of the screw tunnels wall in the fractured vertebral bodies were measured in patients whose pedicle screws were removed, and they were then compared with the values of vertebral cortical bone. Second, an adult patient was included and the CT images of the lumbar spine were harvested. Three dimensional finite element models of the L1 vertebra with unilateral or bilateral screw tunnels were created based on the CT images. Different compressive loads were vertically acted on the models. The maximum loads which the models sustained and the distribution of the force in the different parts of the models were recorded and compared with each other.ResultsThe CT values of the tunnels wall and vertebral cortical bone were 387.126±62.342 and 399.204±53.612, which were not statistically different (P=0.149). The models of three dimensional tetrahedral mesh finite element of normal lumbar 1 vertebra were established with good geometric similarity and realistic appearance. After given the compressive loads, the cortical bone was the first one to reach its ultimate stress. The maximum loads which the bilateral screw tunnels model, unilateral screw tunnel model, and normal vertebral model can sustain were 3.97 Mpa, 3.83 Mpa, and 3.78 Mpa, respectively. For the diameter of the screw tunnels, the model with a diameter of 6.5 mm could sustain the largest load. In addition, the stress distributing on the outside of the cortical bone gradually decreased as the thickness of the tunnel wall increased.ConclusionsBased on the FEA, pedicle screw tunnels would not decrease the biomechanical stability and strength of the vertebral body. A large diameter of screw tunnel and thick tunnel wall were helpful for the biomechanical stability of the vertebral body.

Is nonstructural bone graft useful in surgical treatment of lumbar spinal tuberculosis?: A retrospective case–control study

AbstractSurgical intervention is an important option for treating spinal tuberculosis. Previous studies have reported different surgical procedures and bone grafts for it. To our knowledge, few studies demonstrated the clinical results of using nonstructural autogenous bone graft in surgical treatment of spinal tuberculosis.The purpose of this study is to compare the clinical outcomes of surgical management lumbar spinal tuberculosis by one-stage posterior debridement with nonstructural autogenous bone grafting and instrumentation versus anterior debridement, strut bone grafting combined with posterior instrumentation.A total of 58 consecutive patients who underwent surgical treatment due to lumbar spinal tuberculosis from January 2011 to December 2013 were included. A total of 22 patients underwent one-stage posterior debridement, nonstructural autogenous bone grafting, and instrumentation (group A), and 36 patients received anterior debridement, strut bone grafting combined with posterior instrumentation (group B). The operative duration, total blood loss, perioperative transfusion, length of hospital stay, hospitalization cost, and complications were recorded. The bony fusion of the graft was assessed by computed tomography scans. American Spinal Injury Association (ASIA) Impairment Scale was used to evaluate the neurological function of patients in the 2 groups.All the patients were followed up, with a mean follow-up duration of 21.6 ± 5.7 months in group A and 22.3 ± 6.2 months in group B (P = 0.47). The average operative duration was 257.5 ± 91.1 minutes in group A and 335.7 ± 91.0 minutes in group B (P = 0.002). The mean total blood loss was 769.6 ± 150.9 mL in group A and 1048.6 ± 556.9 mL in group B (P = 0.007). Also, significant differences were found between the 2 groups in perioperative transfusion volumes, length of hospital stay, and hospitalization cost (P < 0.05), which were less in group A compared with group B. Patients with ASIA grade C/D in the 2 groups were improved with 1 to 2 grades after the surgery with no statistical difference (P = 1.000). The perioperative complications rate was 9.1% (2/22) in group A and 13.9% (5/36) in group B (P = 0.897).Based on a retrospective study, the procedure of one-stage posterior debridement, nonstructural autogenous bone grafting, and instrumentation has a significant shorter operative duration, lower blood loss and perioperative transfusion, shorter hospital stay, and less hospitalization cost compared with the one of anterior debridement, strut bone grafting combined with posterior instrumentation for treating lumber spinal tuberculosis.