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BACKGROUND:Emerging evidence demonstrates that low density lipoprotein receptor-related protein 1 (LRP1)isinvolved in lipid metabolism and regulation of inflammatory reaction. OBJECTIVE:To explore the effectof lentivirus-induced knockdown of low density lipoprotein receptor-related protein 1 on cartilage damage and matrix metaloproteinase 13 in a rat model of osteoarthritis, so as to assess the role of low density lipoprotein receptor-related protein 1 in the pathogenesis of osteoarthritis. METHODS:Sixty-fourSprague-Dawleyratswere included andramdomlydivided into four groups (n=16 for each): negative control group, no surgery; sham-surgery group, onlythearticular cavity of the knee was exposed; osteoarthritisplus shLRP1 group, rat osteoarthritis models were established by cutting anterior cruciate ligament and removing the medial meniscus partly folowed by an intra-articular injection of lentivirus-mediated siRNA at 2 days after surgery, once a week for 2 consecutive weeks; osteoarthritis group,an intra-articular injection of the negative control lentivirus was performed after surgery. Rats inthe four groups started running on theself-made electric treadmil from 5 days after modeling, 30 minutes per day,totaly 500 meters. Cartilage damage and matrix metaloproteinase 13 expression in cartilage tissues were determined at 2, 4, 6 weeks after surgery. RESULTS AND CONCLUSION:Gross and pathological observations showed that lentivirus-induced knockdown of lowdensity lipoprotein receptor-related protein 1 aggravatedcartilage damage intherat model of osteoarthritis. At 6 weeks after surgery, Mankin’s scoreand matrix metaloproteinase 13 expression inthecartilage tissues in osteoarthritis plus shLRP1 groupweresignificantly increased compared with other three groups (P< 0.05). These findings indicate that a simulation model of osteoarthritis is developed by cutting anterior cruciate ligament and removing the medial meniscus partly combined with running onthe treadmil. Lentivirus-induced knockdown ofLRP1aggravates cartilage damage in a rat model of osteoarthritis
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BACKGROUND:Tumor necrosis factor α, as a pathogenic factor, induces the inflammatory reaction mainlyvia the activation of the nuclear factor kappa B signaling pathway. Low density lipoprotein receptor-related protein 1 (LRP1) is involved in the regulation of the inflammatory reaction induced by cytokines. OBJECTIVE:To study the effect of knockdown of LRP1 on tumor necrosis factor α-induced inflammatory reaction. METHODS: Primary cultured rat chondrocytes were transfected with lentivirus-mediated RNA interference to knockdown LRP1 gene. Three days after lentivirus transfection, chondrocytes were pretreated with Bay 11-7082 (10 μmol/L) for 30 minutes prior to the addition of tumor necrosis factor α (30 μg/L) for 30 minutes. Signaling protein and mRNA expressions in chondrocytes were detected by western blot assay and real-time PCR analysis, respectively. Chondrocytes were pretreated with or not Bay 11-7082 (10 μmol/L) 30 minutes prior to the addition of tumor necrosis factor α (30 μg/L) for 12 hours after starvation in DMEM for overnight, and the culture medium was colected for ELISA determination of matrix metaloproteinase 13 level. RESULTS AND CONCLUSION:Tumor necrosis factor α receptor 1 expression was upregulated in chondrocytes after lentivirus-induced knockdown of LRP1. Increased expression of inducible nitric oxide synthase and activation of the nuclear factor kappa B signaling pathway were found after the addition of tumor necrosis factor α in shLRP1 group. Moreover, increased level of matrix metaloproteinase 13 was determined by ELISA. Taken together, knockdown of LRP1 up-regulates the expression of tumor necrosis factor α-induced inducible nitric oxide synthase and matrix metaloproteinase 13 through the activation of the nuclear factor kappa B signaling pathway.
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BACKGROUND:Atlantoaxial anatomical structures were special. Compared with thoracolumbar vertebrae, there is no fixed anatomical marker for screw implantation. Moreover, pedicle structural variation is great. The current consensus view is to suggest an individualized program of pedicle screws. The development of orthopedic digital software technology provides a novel manner for preoperative design. OBJECTIVE:To original y design 3D matrix model, to observe atlas pedicle channel, pedicle screw safety zone, to measure optimal program for screw fixation, and to simplify preoperative design of entering pedicle screw. METHODS:Continuous atlas CT data of 12 healthy adults in picture archiving and communication system of People’s Hospital, Three Gorges University were imported into Mimics 10.01 software. There were seven males and five females, at the age of 30-65 years old, averagely 45 years. After three-dimensional reconstruction, the three-dimensional reconstruction models were imported into 3Dmax 2009 as .dwg format. The reference three-dimensional planes and the sites of nail insertion were determined by the atlas modeling. The modeling consisted of 17×17×2 elements and the transverse section angles ranged from 0° to 40° and the sagittal section angles ranged from 0° to 40° with a space of 2.5°. 578 elements were used to simulate pedicle screw array model. Perspective observation showed that the diameter was 3.5 mm, and length was 22 mm in pedicle channel. Thus, safety area, best screw channel and screw angle were analyzed. RESULTS AND CONCLUSION:The total number of elements in the matrix study was 17×17×2×12 in 12 subjects. 175 screws in total of 6 936 units could safely meet the operative standard. No significant difference in the number of pedicle screw between left and right sides (P>0.05). Results indicated that the digital three-dimensional modeling technology is an effective, simple, accurate way in the preoperative design and measurement for atlas pedicle surgery.
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ObjectiveTo investigate the relationship between intervertebral disc pressure and clinical efficacy after the minimally invasive treatment of cervical disc herniation. MethodsForty-seven patients with cervical disc herniation treated by disc radiofrequency ablation, and monitored the intervertebral disc pressure after that. Moreover, the correlation between the pressure and the clinical efficacy was observed. ResultsAll cases were successfully completed under pressure monitoring. Forty-seven cases underwent a follow-up of 1-25 months,according to JOA score,using postoperative improvement rate (Hirabashi formula) to assess the clinical efficacy. High efficacy in 25 cases,fine efficacy in 19 cases,good efficacy in 3 cases,high and fine efficacy rate was 93.6％ (44/47). The postoperative intervertebral discpressure was significantly correlated with improvement rate after cervical minimally invasive surgery (P ＜0.05). ConclusionsRadiofrequency ablation treatment of cervical disc herniation is safe and effective minimally invasive technique. If the pressure in the postoperative intervertebral disc is 3 kPa,it will get better prognosis.
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Objective To investigate the mid-term efficacy of percutaneous laser disc decompression(PLDD) for patients with lumbar disc herniation.Methods Between May 2001 and December 2006,a total of 122 patients with simple lumbar disc herniation underwent PLDD in our hospital.Under local anesthesia,the operaiton was performed using a laser diode with the patients in supine position.A C-arm X-ray system was employed to guide the surgery.Results The patients were followed up for 6 to 60 months(mean 36.5 months).Accroding to the MacNab Criteria,60 patients achieved excellent outcomes,39 were good,15 were fair,and 8 were poor.The rate of exellent and good outcomes was 81.1%(99/122).No patient had postoperative complications.Conclusions PLDD is effective and safe for patients with simple lumbar disc herniation.The cases recover quickly after the operation,because the procedure is minimally invasive.