Objective:To investigate the improved superantigen activity of SEC2(T20L/G22E) compared with recombinant staphylococcal enterotoxins C 2 ( rSEC2 ).Methods: The proliferation of spleen lymphocytes and T-cell subpopulations induced by rSEC2 and SEC2(T20L/G22E) were examined by WST-1 and flow cytometry separately,and the gene expression of cytokines and Vβspecificities were quantified by real-time PCR.Results: WST-1 and Flow cytometry assays showed that the superantigen activity of SEC2(T20L/G22E) was improved due to enhanced T-cell stimulating potency,resulting in massive activation of T-cells,particularly CD4+and CD8+T-cells.Quantitative real-time PCR assay showed that despite similar Vβspecificities induced by rSEC 2 and SEC2 (T20L/G22E),the quantities of activated T-cells bearing specific Vβwere different,and SEC2(T20L/G22E) could stimulate more gene expression of associated cytokines simultaneously.Conclusion: The results strongly suggested that the increased SEC 2 ( T20L/G22 E)-TCR-binding affinity contributed to more T-cells activation and cytokine release ,which elicit powerful immune activition.

Objective:To evaluate the clinical effect of percutaneous curved kyphoplasty (PCK) for osteoporosis vertebral compression fractures (OVCF).Methods:This is a prospective study.Patients with OVCF who underwent PCK at the Department of Orthopedics,Beijing Chaoyang Hospital, Capital Medical University from June 2018 to June 2019 were included.All the operations were performed by the same surgeon.X-ray examination was performed before and after the operation to measure the vertebral height and Cobb angle.The visual analogue scale (VAS) and Oswestry disability index (ODI) scores were evaluated before and after the operation,and the amount of bone cement injected was record.The leakage rate and distribution of bone cement was observed by CT examination after the operation,and the postoperative complications was collected during the follow-up.Paired- t test was used to compare the related indexes before and after operation. Results:There were 32 patients in our study,including 8 males and 24 females,aged (74.9±9.9) years (range:64 to 81 years).The intraoperative bone cement injection volume was (4.2±1.5) ml(range:2 to 6 ml).According to the classification of distribution of bone cement,28 cases were rated as type Ⅰ and 4 cases were rated as type Ⅱ. Bone cement leakage was observed in 12 cases (37.5%),and there was no intraspinal leakage or venous leakage.The vertebral height was improved from (21.9±6.2) mm preoperatively to (24.3±4.3) mm postoperatively( t=-2.836, P=0.008),Cobb angle improved from( M( QR))14°(15°)preoperatively to 12.5°(12.75°)postoperatively( Z=-1.950, P=0.051),VAS improved from 6.8±0.7 preoperatively to 1.7±0.8 postoperatively ( t=28.946, P<0.01),ODI score improved from 73.4±7.3 preoperatively to 21.3±5.7 postoperatively ( t=32.250, P<0.01).The patients were followed up for (19.7±3.7) months (range:15 to 29 months).One patient had refracture (3.1%,1/32),and no other complications such as neurological dysfunction and pulmonary embolism occurred. Conclusions:The clinical effect of PCK in the treatment of OVCF was satisfactory.This technique could reduce the difficulty of puncture to a certain extent,and be beneficial to the distribution of bone cement.

Objective:To evaluate the clinical effect of percutaneous curved kyphoplasty (PCK) for osteoporosis vertebral compression fractures (OVCF).Methods:This is a prospective study.Patients with OVCF who underwent PCK at the Department of Orthopedics,Beijing Chaoyang Hospital, Capital Medical University from June 2018 to June 2019 were included.All the operations were performed by the same surgeon.X-ray examination was performed before and after the operation to measure the vertebral height and Cobb angle.The visual analogue scale (VAS) and Oswestry disability index (ODI) scores were evaluated before and after the operation,and the amount of bone cement injected was record.The leakage rate and distribution of bone cement was observed by CT examination after the operation,and the postoperative complications was collected during the follow-up.Paired- t test was used to compare the related indexes before and after operation. Results:There were 32 patients in our study,including 8 males and 24 females,aged (74.9±9.9) years (range:64 to 81 years).The intraoperative bone cement injection volume was (4.2±1.5) ml(range:2 to 6 ml).According to the classification of distribution of bone cement,28 cases were rated as type Ⅰ and 4 cases were rated as type Ⅱ. Bone cement leakage was observed in 12 cases (37.5%),and there was no intraspinal leakage or venous leakage.The vertebral height was improved from (21.9±6.2) mm preoperatively to (24.3±4.3) mm postoperatively( t=-2.836, P=0.008),Cobb angle improved from( M( QR))14°(15°)preoperatively to 12.5°(12.75°)postoperatively( Z=-1.950, P=0.051),VAS improved from 6.8±0.7 preoperatively to 1.7±0.8 postoperatively ( t=28.946, P<0.01),ODI score improved from 73.4±7.3 preoperatively to 21.3±5.7 postoperatively ( t=32.250, P<0.01).The patients were followed up for (19.7±3.7) months (range:15 to 29 months).One patient had refracture (3.1%,1/32),and no other complications such as neurological dysfunction and pulmonary embolism occurred. Conclusions:The clinical effect of PCK in the treatment of OVCF was satisfactory.This technique could reduce the difficulty of puncture to a certain extent,and be beneficial to the distribution of bone cement.