ABSTRACT
BACKGROUND: Chinese medicine is effective for preventing and treating glucocorticoid-induced osteoporosis, however, the underlying mechanism remains unclear. DKK1, an inhibitor of Wnt/β-catenin signaling pathway, can be up-regulated by glucocorticoid. Thereafter, DKK1 is an important target in the prevention and treatment of osteoporosis. OBJECTIVE: To explore the regulatory effect of Zuogui pill on DKK1 in the prevention and treatment of glucocorticoid-induced osteoporosis. METHODS: Eighteen three-month-old female Sprague-Dawley rats were randomly divided into three groups: control group, model group and Zuogui pill group. Rats in the model and Zuogui pill groups received the subcutaneous injection of dexamethasone to establish the model of glucocorticoid-induced osteoporosis. The Zuogui pill group rats were administrated Zuogui pill extracts, and the control rats were given the same volume of normal saline. At 1 month after modeling, the lumbar vertebrae were removed to test the bone mass and microstructures by micro-CT scanning. The biomechanical properties were detected by compression test. The mRNA expression levels of DKK1, Runx2 and CTSK were determined by Qpcr. The serum alkaline phosphatase activity was tested. RESULTS AND CONCLUSION: Compared with the control group, in the model group, the volumetric bone mineral density, trabecular bone volume fraction, trabecular number, and trabecular thickness were significantly decreased (P ＜ 0.05), the trabecular separation and structure model index were significantly increased (P ＜ 0.05). The serum alkaline phosphatase activity was on a decline. The mRNA expression level of DKK1 showed a significant up-regulation (P ＜ 0.05). The mRNA expression level of Runx2 showed a down-regulated trend while mRNA expression level of CTSK showed an up-regulated trend. Compared with the model group, the Zuogui pill group showed significantly enhanced volumetric bone mineral density, trabecular bone volume fraction, and trabecular number (P ＜ 0.05); the structure model index was significantly decreased (P ＜ 0.05); the trabecular separation was reduced; the serum alkaline phosphatase activity was enhanced; the mRNA expression level of DKK1 showed a significant down-regulation (P ＜ 0.05); the mRNA expression level of Runx2 showed an up-regulated trend while mRNA expression level of CTSK showed a down-regulated trend. The vertebral compressive strength in the Zuogui pill group was significantly higher than that in the model group (P＜0.05). In summary, Zuogui pill prevents and treats glucocorticoid-induced osteoporosis possibly through the down-regulation of mRNA expression of DKK1.
ABSTRACT
Objective To compare the biomechanical differences in 3 posterior fixation methods with or without crosslink for treatment of thoracolumbar fractures, so as to find the optimal posterior fixation methods. Methods On the basis of the validated finite element model of T12-L2 segments to simulate L1 vertebra burst fracture, the superior 1/2 cortical bone of T12 segment was removed and the superior 1/2 cancellous bone was assigned with the material damage property of cancellous bone. Then 6 thoracolumbar fracture models by intermediate unilateral pedicle screw fixation without or with crosslink (Model A1, A2), traditional short-segment pedicle screw fixation without or with crosslink (Model B1, B2), intermediate bilateral pedicle screw fixation without or with crosslink (Model C1,C2) were established, respectively. The range of motion (ROM) as well as the maximum Von Mises stress of the pedicle screw and rod for 6 models under various physiological loading conditions were compared. Results The ROM under flexion-extension and lateral bending in Model A and Model C was obviously smaller than that of Model B. Under flexion-extension, no significant difference was found in ROM between Model A and Model C; under lateral bending, the ROM of Model C was smaller than that of Model A. The stress was concentrated in the root of upper screw and the rob located between upper screw and intermediate screw; the maximum stress of upper screw in Model C was smaller than that in Model A and Model B. The crosslink could increase the stability of all fixation groups under axial rotation stress condition, and decrease the maximum stress on upper screw and rod under axial rotation stress condition, but no significant difference was found under flexion-extension and lateral bending. Conclusions Additional pedicle screws at the level of fracture vertebra can achieve the better biochemical stability. The additional crosslink not only increases the torsional rigidity, but also decreases the maximum torsional stress of the screw and rod, which is a better choice as the treatment of thoracolumbar fractures.
ABSTRACT
<p><b>OBJECTIVE</b>To establish a method of detecting spinal tuberculosis (TB) infection by enzyme-linked immunospot (ELlSPOT) assay and evaluate the value of CFP10/ESAT6 fusion protein for diagnosis of spinal TB.</p><p><b>METHODS</b>Suspected spinal TB patients were prospectively recruited in two hospitals (First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine; Nanfang Hospital, Southern Medical University) from May 2012 to December 2013. Data on clinical characteristics of the patients and conventional laboratory results were collected. Compare and analyze the positive detection rate in spinal TB diagnosis by different methods including ELISPOT detection and conventional detection methods.</p><p><b>RESULTS</b>47 patients with spinal TB had available biopsy or surgical specimens for histopathological examination and 41 specimens had pathological features consistent with a diagnosis of TB infection. Among the spinal TB patients and non-TB disease patients,the overall sensitivity, specificity, positive predictive value, and negative predictive value of the ELISPOT assay in spinal TB diagnosis were 82.7%,87.2%,89.6%, and 79.1%,respectively; the 4 indexes of the PPD skin test were 61.5%, 46.2%, 60.4%, and 47.4%, respectively;those of the antibody detection were 55.8%, 61.5%, 65.9%, and 51.1%. The positive rate of ELISPOT was significantly higher than those of PPD skin test and antibody detection test (82.7% vs. 61.5%, Χ² =5.786, P=0.016; 82.7% vs. 55.8%, Χ² =8.847, P=0.003), but not significantly different from the positive rate of pathological examination (82.7% vs. 87.2%, Χ² =0.396, P=0.529). Moderate agreement was found between pathological examination and the ELISPOT assay (87.2%, Κ=0.498, P=0.001).</p><p><b>CONCLUSION</b>With high sensitivity and specificity, the ELISPOT assay using CFP10/ESAT6 fusion protein as antigen is an effective technique for auxiliary diagnosis of spinal TB.</p>