Objective To Screen the carbapenem-resistant acinetobacter baumannii so as to understand the drug resistance,and to analyze the outer membrane protein expression between the carbapenem-resistant Acinetobacter baumannii and the sensitive strains.Methods The twofold agar dilution method was used to screen the carbapenem-resistant acinetobacter baumannii.PCR technique was used to detect the outer membrane protein-encoding gene carO.SDS-PAGE was used to analyze the expression of outer membrane protein.Results 32 strains were carbapenem-resistant acinetobacter baumannii separated from 1 10 strains,which were 100% sensitive to polymyxin B and were resistant to other drugs with different degrees O.They all carried carO gene.There were different protein bands between the carbapenem-resistant strains and the sensitive strains,in which two protein bands of 50× 10 3 and 22×10 3 were recognized as outer membrane proteins through the analysis of SDS-PAGE.Conclusion Drug resistance of acinetobacter baumannii is serious,and the outer membrane protein expression between the carbapenem-resistant strains and the sensitive strains presents discrepancy.

Objective:To explore the application of a 3D printed patient-specific guider (3D-PSG) in complex total knee arthroplasty (TKA).Methods:A retrospective analysis was performed of the data of 44 patients who had received complex artificial TKA for articular and extra-articular deformities of the knee from January 2016 to October 2019 at Department of Orthopaedic Surgery, Nanjing First Hospital. According to whether a 3D-PSG had been applied, the patients were divided into 2 groups. In the 3D-PSG group of 23 patients, there were 11 males and 12 females, with an age of 63.7 years ± 10.2 years (from 53 to 81 years); in the conventional group of 21 cases, there were 10 males and 11 females, with an age of 64.2 years ±12.1 years (from 51 to 79 years). In the 3D-PSG group, the preoperative CT data were 3D reconstructed for measurement of a full lower limb and design of a 3D-PSG and TKA was assisted by a 3D-PSG which had been manufactured by a 3D printer using the STL files of the 3D-PSG imported. In the conventional group TKA was performed in a standard manner. In the 3D-PSG group, the TKA surgical parameters in the preoperative plan were compared with actual surgical measurements. The 2 groups were compared in terms of operation time, intraoperative blood loss, postoperative drainage volume, length of hospital stay, visual analogue scale (VAS), Knee Society Score (KSS), hip knee ankle (HKA), frontal femoral component (FFC), frontal tibial component (FTC), lateral femoral flexion (LFF) and lateral tibial component (LTC).Results:There were no significant differences between the 2 groups in the preoperative general data, showing comparability ( P>0.05). In the 3D-PSG group, no significant differences were found between preoperative parameters designed and actual intraoperative measurements in the prosthetic type of femoral condyle (3.4±1.1 versus 3.5±0.9) or of tibial plateau (3.1±0.9 versus 3.3±1.2), or in the filler thickness (10.6 mm ± 3.2 mm versus 10.9 mm ± 4.7 mm) ( P>0.05). The 44 patients were followed up for an average of 10.8 months (from 7 to 13 months). The 3D-PSG group had significantly less operation time (65.7 min ± 10.5 min), intraoperative blood loss (19.8 mL ±7.3 mL), postoperative drainage volume (124.6 mL ± 27.9 mL) and hospital stay (7.3 d ± 2.5 d) than the conventional group (82.4 min ± 11.7 min, 86.5 mL ± 35.7 mL, 154.6 mL ± 21.3 mL and 10.6 d ± 3.1 d) ( P<0.05). The VAS and KSS scores at postoperative day 1, week 1 and week 2 in the 3D-PSG group were significantly better than those in the conventional group ( P<0.05). Significantly more patients in the 3D-PSG group achieved approximately ideal values in HKA, FFC, FTC, LFF and LTC than those in the conventional group ( P<0.05). Conclusion:A 3D printed patient-specific guider may improve surgical accuracy, reduce operation time and achieve better surgical outcomes in complex total knee arthroplasty.