Objective To investigate the clinical effect of unilateral percutaneous vertebroplasty(PVP)combined with 3D printing technology for the treatment of thoracolumbar osteoporotic compression fracture.Methods A total of 77 patients with thoracolumbar osteoporotic compression fractures from October 2020 to April 2022 were included in the study,all of which were vertebral body compression fractures caused by trauma.According to different treatment methods,they were di-vided into experimental group and control group.Thirty-two patients used 3D printing technology to improve unilateral transpedicle puncture vertebroplasty in the experimental group,there were 5 males and 27 females,aged from 63 to 91 years old with an average of(77.59±8.75)years old.Forty-five patients were treated with traditional bilateral pedicle puncture vertebroplasty,including 7 males and 38 females,aged from 60 to 88 years old with an average of(74.89±7.37)years old.Operation time,intraoperative C-arm X-ray times,anesthetic dosage,bone cement injection amount,bone cement diffusion good and good rate,complications,vertebral height,kyphotic angle(Cobb angle),visual analogue scale(VAS),Oswestry disability index(ODI)and other indicators were recorded before and after surgery,and statistically analyzed.Results All patients were followed up for 6 to 23 months,with preoperative imaging studies,confirmed for thoracolumbar osteoporosis com-pression fractures,two groups of patients with postoperative complications,no special two groups of patients'age,gender,body mass index(BMI),time were injured,the injured vertebral distribution had no statistical difference(P＞0.05),comparable data.Two groups of patients with bone cement injection,bone cement dispersion rate,preoperative and postoperative vertebral body height,protruding after spine angle(Cobb angle),VAS,ODI had no statistical difference(P＞0.05).The operative time,intra-operative fluoroscopy times and anesthetic dosage were statistically different between the two groups(P＜0.05).Compared with the traditional bilateral puncture group,the modified unilateral puncture group combined with 3D printing technology had shorter operation time,fewer intraoperative fluoroscopy times and less anesthetic dosage.The height of anterior vertebral edge,kyphosis angle(Cobb angle),VAS score and ODI of the affected vertebrae were statistically different between two groups at each time point after surgery(P＜0.05).Conclusion In the treatment of thoracolumbar osteoporotic compression fractures,3D printing technology is used to improve unilateral puncture PVP,which is convenient and simple,less trauma,short operation time,fewer fluoroscopy times,satisfactory distribution of bone cement,vertebral height recovery and kyphotic Angle correction,and good functional improvement.

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

Objective:To investigate the clinical efficacy of over-the-top reconstruction combined with the modified Lemaire technique in the treatment of anterior cruciate ligament (ACL) injuries with pivot-shift positive.Methods:From March 2020 to October 2021, a total of 46 patients with ACL injury and pivot-shift test grade II or above were admitted to Xinhua Hospital Affiliated to Dalian University. There were 28 males and 18 females, aged 28.0±10.5 years (range, 15-45 years). All cases were unilateral, including 17 cases of left knee and 29 cases of right knee. The pivot-shift test showed that 30 cases were grade II and 16 cases were grade III, and the cause of injury was sports injury. The semitendinosus muscle and gracilis muscle were harvested, and the ACL was reconstructed with the over-the-top combined modified Lemaire technique. The International Knee Documentation Committee (IKDC) score, Lysholm score and KT-2000 side-to-side difference before and after operation were compared.Results:All patients successfully completed the operation and were followed up for 26.6±2.3 months (range, 24-28 months). The Lysholm scores of the patients at 3 months and 24 months after operation were 73.6±4.3 and 91.6±2.8, which were higher than those before operation (58.5±4.6), and the difference was statistically significant ( F=18.351, P<0.001). The IKDC scores of patients at 3 months and 24 months after operation were 59.0±2.0 and 91.8±3.2, respectively, which were higher than those before operation 50.3±2.8, and the difference was statistically significant ( F=17.290, P<0.001). The side-to-side difference of KT-2000 was 1.7±0.8 mm and 1.5±0.4 mm at 3 and 24 months after operation, respectively, which was lower than that before operation (5.9±1.1 mm), and the difference was statistically significant ( F=14.192, P<0.001). At 24 months after operation, 3 patients had pivot shift test grade I and 4 patients had Lachman test grade I, but they complained of good knee stability and did not receive further treatment. At the last follow-up, there were no complications such as incision and intra-articular infection, deep vein thrombosis, knee stiffness, quadriceps musculus ossificans myositis, and reconstruction ligament rupture. All patients returned to sports with an average time of 15.7±2.6 months (range, 12-24 months). Conclusion:Over-the-top reconstruction combined with the modified Lemaire technique for the treatment of ACL injury with positive pivot shift test effectively improves knee function and promotes the patient's return to sports, with a low incidence of surgical complications.

Objective:To evaluate the short-term clinical outcomes of meniscus reconstruction using autologous peroneus longus tendon grafts.Methods:A retrospective analysis was conducted on 20 patients (12 males, 8 females) with a mean age of 37.8±5.7 years (range, 31-47 years) and a mean body mass index (BMI) of 26.3±5.8 kg/m 2 (range, 20.1-31.3 kg/m 2) who underwent meniscal reconstruction with autologous peroneus longus tendon in Affiliated Xinhua Hospital of Dalian University from June 2020 to June 2022. A control group of 20 patients (15 males, 5 females), with a mean age of 39.1±6.2 years (range, 32-47 years) and a mean BMI of 25.6±5.4 kg/m 2 (range, 20.2-32.7 kg/m 2), underwent partial meniscectomy during the same period. Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, visual analogue scale (VAS) for pain, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 3, 6, 12, and 24 months postoperatively. The morphology and signal intensity of grafts, Recht grading for cartilage damage, and the need for secondary arthroscopy were also evaluated. Results:The mean follow-up duration was 24.3±4.3 months for the tendon graft group and 24.2±3.6 months for the partial meniscectomy group. At 3 and 6 months postoperatively, the partial meniscectomy group demonstrated superior knee function scores compared to the tendon graft group ( P<0.05). Similarly, VAS were lower in the partial meniscectomy group at 3 months postoperatively ( P<0.05), although no significant difference was found at 6 months ( P>0.05). By 12 months postoperatively, differences in pain and function between the two groups were no longer statistically significant ( P>0.05). At 24 months, the tendon graft group exhibited significantly better outcomes in terms of the Lysholm score (84.31±12.20 vs. 72.67±14.18), IKDC score (82.21±10.55 vs. 74.09±11.68), VAS score (2.10±1.74 vs. 3.80±1.81), and KOOS score (85.37±13.14 vs.75.14±17.94) compared to the partial meniscectomy group ( P<0.05). Regarding graft healing, 19 patients in the tendon graft group demonstrated a grade 3 graft-residual meniscus complex at 24 months, significantly improved from 5 patients at 3 months postoperatively. Furthermore, no grafts showed a grade 3 signal intensity at 3 months, while 19 patients showed such improvements by 24 months. MRI at the 24-month follow-up revealed cartilage damage in 7 patients in the tendon graft group and 20 patients in the partial meniscectomy group, with severe cartilage damage (Recht grade>II) observed in 1 patient in the tendon graft group and 7 patients in the partial meniscectomy group. All 20 patients in the tendon graft group achieved minimal clinically significant differences by 24 months, and 4 of them underwent secondary arthroscopy, which revealed vascularization between the graft and residual meniscal tissue. Conclusion:The use of the peroneus longus tendon for meniscal reconstruction reduces knee pain, enhances knee function, and effectively fills the tibiofemoral joint space while protecting the articular cartilage through graft remodeling.

Objective To investigate the clinical effect of anterior cervical discectomy and fusion(ACDF)in the treatment of cervical spondylosis of vertebral artery type(CSA).Methods The clinical data of 42 patients with CSA from January 2020 to January 2022 were retrospectively analyzed.There were 25 males and 17 females,aged from 30 to 74 years old with an average of(53.9±11.0)years old.There were 18 cases with single-segment lesions,17 cases with two-segment lesions,and 7 cases with three-segment lesions.The American Academy of Otolaryngology-Head and Neck Surgery's Hearing and Balance Committee score(CHE),the Neck Disability Index(NDI)and the cervical curvature Cobb angle were recorded before surgery and after surgery at 6 months.Results All 42 ACDF patients were followed up for 6 to 30 months with an average of(14.0±5.2)months.The operative time ranged from 95 to 220 min with an average of(160.38±36.77)min,the intraoperative blood loss ranged from 30 to 85 ml with an average of(53.60±18.98)ml.Tow patients had mild postoperative dysphagia,which improved with symptomatic treatment such as nebulized inhalation.CHE score decreased from(4.05±0.96)preoperatively to(2.40±0.70)at 6 months postoperatively(t=12.97,P＜0.05).The number of improved vertigo at 6 months postoperatively was 38,with an im-provement rate of 90.5％.NDI score was reduced from(34.43±8.04)preoperatively to(20.76±3.91)at 6 months postopera-tively(t=1 1.83,P＜0.05).The cervical curvature Cobb angle improved from(8.04±6.70)° preoperatively to(12.42±5.23)° at 6 months postoperatively(t=-15.96,P＜0.05).Conclusion The ACDF procedure has outstanding clinical efficacy in treating CSA.The operation can rapidly relieve patients'episodic vertigo symptoms by relieving bony compression and reconstructing cervical curvature.However,it is necessary to strictly grasp the indications for surgery and clarify the causes of vertigo in pa-tients,and ACDF surgery is recommended for CSA patients for whom conservative treatment is ineffective.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.