Objective To investigate the effects of aggrecanase-2 knockdown in chondrocytes from rheumatoid arthritis patient by shRNA infection.Methods Cartilage harvested from rheumatoid arthritis patients who underwent total knee arthroplasty was digested by pancreatin and type Ⅱ collagen enzyme to obtain chondrocytes.Then chondrocytes were cultured and passaged to second or third generation.After aggrecanase-2 shRNA5,aggrecanase-2 shRNA6,aggrecanase-2 shRNA7,aggrecanase-2 shRNA8 infection,growth and morphological changes of the chondrocytes were examined.To select the best target sequence,mRNA expression of aggrecanase-2 and aggrecan was detected by RT-qPCR assay on day 2,5,10,represented with Ct (Cycle threshold) value.Expression of aggrecan protein was detected by immunocytochemistry,represented with IOD (integral optical density) value.Results aggrecanase-2 knockdown had no obvious effects on the morphology and growth of the chondrocytes.MOI (multiplicity of infection) was 100,50,25,and infection efficiency was 90％,60％,30％ with the corresponding viral load of 200 μl,100 μl,50 μl after transfection.mRNA expression of aggrecanase-2 was suppressed significantly,especially the group of shRNA5 which suppressed aggrecanase-2 expression from 0.876 3±0.115 6 to 0.069 9±0.015 1 (P ＜ 0.05).mRNA and protein expression of aggrecan were significantly upregulated after infection.mRNA expression of aggrecan increased from 0.992 1±0.201 3 to 3.049 2±0.278 2 (P ＜ 0.05) and protein expression of aggrecan increased from 496.160 5± 225.673 7 to 4 525.433 0±1 131.813 0 (P ＜ 0.05).Conclusion aggrecanase-2 suppression in chondrocytes by lentivirius infection is an effective method to protect the expression of aggrecan.

Objective:To evaluate the efficacy of percutaneous vertebroplasty (PVP) by percutaneous bi-level bilateral puncture in the treatment of type ⅡA acute symptomatic osteoporotic thoracolumbar fracture (ASOTLF) with dense bone bands.Methods:From March 2017 to March 2018, 65 patients (65 vertebrae) with type ⅡA ASOTLF with dense bone bands were treated at Department of Orthopaedic Trauma, Qingdao Central Hospital. They were 25 males and 40 females, with an age of (71.6±8.4) years. The time from injury to operation was (3.5±0.7) d. They were divided into 2 groups according to different treatments. In the observation group of 31 cases (31 vertebrae), PVP was conducted by percutaneous bi-level bilateral puncture; in the control group of 34 cases (34 vertebrae), PVP was conducted by percutaneous single-level bilateral puncture. The 2 groups were compared in terms of operation time, volume of polymethyl methacrylate injected, incidence of bone cement leakage, incidence of vertebral refracture, diffusive distribution of bone cement in the vertebral body, and visual analogue scale (VAS) and Oswestry dysfunction index (ODI) at postoperative 1 day and 6 months.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). Operations were completed uneventfully in all the 65 patients. All the 65 patients were followed up for (8.2±1.2) months. There was no significant difference between the 2 groups in operation time, incidence of bone cement leakage or incidence of vertebral refracture for each vertebral body injured ( P>0.05). The volume of polymethyl methacrylate injected [(6.64±0.93) mL] and the excellent and good rate of diffusive distribution of bone cement in the vertebral body [87.1% (27/31)] in the observation group were significantly larger than those in the control group [(4.36±0.79) mL and 64.7% (22/34)] ( P<0.05). The VAS scores at postoperative 1 day and 6 months [2 (1, 2) and 1 (1, 2)] and ODIs at postoperative 1 day and 6 months (23.7%±1.6% and 18.8%±1.4%) in the observation group were significantly lower than those in the control group [2 (2, 3) and 2 (2, 2); 26.9%±4.2% and 22.1%±3.3%] ( P<0.05). The VAS scores and ODIs at postoperative 1 day and 6 months in all patients were significantly lower than those before operation ( P<0.05). Compression symptoms of the spinal cord and nerve root were observed in none of the patients. Conclusion:In the treatment of type ⅡA ASOTLF with dense bone bands, PVP by percutaneous bi-level bilateral puncture is more effective than the traditional PVP by percutaneous single-level bilateral puncture, and will not increase bone cement leakage or vertebral refracture.

Objective:To analyze the clinical characteristics and management strategies of the patients who were injured in winter snow sports in parts of Qingdao in order to provide useful information for "300 million people participating in ice and snow sports" .Methods:A retrospective study was conducted to analyze the data of 128 patients who had been admitted to Department of Orthopaedics, Qingdao Central Hospital for skiing injuries from November 2019 to March 2021. The gender, type, location and cause of injury, and treatment method of the patients were statistically analyzed.Results:Of the 128 patients, 72 were males and 56 females with an age of (32.0±12.1) years. Single injury accounted for 97.66% (125/128) while multiple injuries 2.34% (3/128). 46 injuries (35.11%, 46/131) due to single board skiing occurred in 44 patients (34.38%, 44/128); 85 injuries (64.89%, 85/131) due to double board skiing occurred in 84 cases (65.62%, 84/128). As for injury types, there were 44 cases (34.38%, 44/128) of soft tissue injury and 84 fractures (65.62%, 84/128). The top 3 injured locations were the lower leg (24.43%, 32/131), the peri-wrist part (18.32%, 24/131), and the peri-knee part (15.27%, 20/131). The most vulnerable location was, respectively, the wrist joint (26.09%, 12/46) in single board skiing and the calf (31.76%, 27/85) in double board skiing. The top three causes of injury were accidental fall (39.06%, 50/128), being struck by someone or emergency evacuation (14.84%, 19/128), and mismatched equipment models (12.50%, 16/128). The proportion of skiing beginners was as high as 76.56% (98/128). Surgical treatment was performed in 49 cases (38.28%, 49/128), and conservative treatment in 79 cases (61.72%, 79/128).Conclusions:The clinical characteristics of the patients who were injured in winter snow sports in parts of Qingdao are high proportions of skiing beginners, falls and fractures. Special attention needs to be paid to wrist protection in single board skiing and checking the ski disengagement device before double board skiing. Most patients may need only conservative treatment because although a number of patients required surgical treatment, severe multiple injuries were rare.

The composition of serum is extremely complex,which complicates the discovery of new pharmaco-dynamic biomarkers via serum proteome for disease prediction and diagnosis.Recently,nanoparticles have been reported to efficiently reduce the proportion of high-abundance proteins and enrich low-abundance proteins in serum.Here,we synthesized a silica-coated iron oxide nanoparticle and devel-oped a highly efficient and reproducible protein corona(PC)-based proteomic analysis strategy to improve the range of serum proteomic analysis.We identified 1,070 proteins with a median coefficient of variation of 12.56％using PC-based proteomic analysis,which was twice the number of proteins iden-tified by direct digestion.There were also more biological processes enriched with these proteins.We applied this strategy to identify more pharmacodynamic biomarkers on collagen-induced arthritis(CIA)rat model treated with methotrexate(MTX).The bioinformatic results indicated that 485 differentially expressed proteins(DEPs)were found in CIA rats,of which 323 DEPs recovered to near normal levels after treatment with MTX.This strategy can not only help enhance our understanding of the mechanisms of disease and drug action through serum proteomics studies,but also provide more pharmacodynamic biomarkers for disease prediction,diagnosis,and treatment.