OBJECTIVES: To study the molecular mechanisms of LDH-loaded si-NEAT1 for regulating paclitaxel resistance and tumor-associated macrophage (TAM) polarization in breast cancer. METHODS: qRT-PCR and Western blotting were used to detect the expression of lncRNA NEAT1, miR-133b, and PD-L1 in breast cancer SKBR3 cells and paclitaxel-resistant SKBR3 cells (SKBR3-PR). The effects of transfection with si-NEAT1 and miR-133b mimics on MRP, MCRP and PD-L1 expressions and cell proliferation, migration and apoptosis were investigated using qRT-PCR, Western blotting, scratch and Transwell assays, and flow cytometry. Rescue experiments were conducted using si-NEAT1 and miR-133b inhibitor. Human THP-1 macrophages were cultured in the presence of conditioned media (CM) derived from SKBR3 and SKBR3-PR cells with or with si-NEAT1 transfection for comparison of IL-4-induced macrophage polarization by detecting the surface markers. LDH@si-NEAT1 nanocarriers were constructed, and their effects on MRP, MCRP and PD-L1 expressions and cell behaviors of the tumor cells were examined. THP-1 cells were treated with the CM from LDH@si-NEAT1-treated tumor cells, and the changes in their polarization were assessed. RESULTS: SKBR3-PR cells showered significantly upregulated NEAT1 and PD-L1 expressions and lowered miR-133b expression as compared with their parental cells. Transfection with si-NEAT1 and miR-133b mimics inhibited viability, promoted apoptosis and enhanced MRP and BCRP expressions in SKBR3-PR cells. NEAT1 knockdown obvious upregulated miR-133b and downregulated PD-L1, MRP and BCRP expressions. The CM from SKBR3-PR cells obviously promoted M2 polarization of THP-1 macrophages, which was significantly inhibited by CM from si-NEAT1-transfected cells. Treatment with LDH@si-NEAT1 effectively inhibited migration and invasion, promoted apoptosis, and reduced MRP, BCRP and PD-L1 expressions in the tumor cells. The CM from LDH@si-NEAT1-treated SKBR3-PR cells significantly downregulated Arg-1, CD163, IL-10, and PD-L1 and upregulated miR-133b expression in THP-1 macrophages. CONCLUSIONS LDH@si-NEAT1 reduces paclitaxel resistance of breast cancer cells and inhibits TAM polarization by targeting the miR-133b/PD-L1 axis.
Humans ; MicroRNAs/genetics* ; RNA, Long Noncoding/genetics* ; Paclitaxel/pharmacology* ; Breast Neoplasms/metabolism* ; Drug Resistance, Neoplasm ; B7-H1 Antigen/metabolism* ; Cell Line, Tumor ; Female ; Tumor-Associated Macrophages ; Apoptosis ; Cell Proliferation ; Macrophages ; Cell Movement

Objective:The emergence of polymyxin-resistant Klebsiella pneumoniae(KPN)in clinical settings necessitates an analysis of its antibiotic resistance characteristics,epidemiological features,and risk factors for its development.This study aims to provide insights for the prevention and control of polymyxin-resistant KPN infections. Methods:Thirty clinical isolates of polymyxin-resistant KPN were collected from the Third Xiangya Hospital of Central South University.Their antibiotic resistance profiles were analyzed.The presence of carbapenemase KPC,OXA-48,VIM,IMP,and NDM was detected using colloidal gold immunochromatography.Hypervirulent KPN was initially screened using the string test.Biofilm formation capacity was assessed using crystal violet staining.Combination drug susceptibility tests(polymyxin B with meropenem,tigecycline,cefoperazone/sulbactam)were conducted using the checkerboard method.Polymyxin-related resistance genes were detected by PCR.Multi-locus sequence typing(MLST)was performed for genotyping and phylogenetic tree construction.The study also involved collecting data from carbapenem-resistant(CR)-KPN polymyxin-resistant strains(23 strains,experimental group)and CR-KPN polymyxin-sensitive strains(57 strains,control group)to analyze potential risk factors for polymyxin-resistant KPN infection through univariate analysis and multivariate Logistic regression.The induction of resistance by continuous exposure to polymyxin B and colistin E was also tested. Results:Among the 30 polymyxin-resistant KPN isolates,28 were CR-KPN,all producing KPC enzyme.Four isolates were positive in the string test.Most isolates showed strong biofilm formation capabilities.Combination therapy showed additive or synergistic effects.All isolates carried the pmrA and phoP genes,while no mcr-1 or mcr-2 genes were detected.MLST results indicated that ST11 was the predominant type.The phylogenetic tree suggested that polymyxin-resistant KPN had not caused a hospital outbreak in the institution.The use of two or more different classes of antibiotics and the use of polymyxin were identified as independent risk factors for the development of polymyxin-resistant strains.Continuous use of polymyxin induced drug resistance. Conclusion:Polymyxin-resistant KPN is resistant to nearly all commonly used antibiotics,making polymyxin-based combination therapy a viable option.No plasmid-mediated polymyxin-resistant KPN has been isolated in the hospital.Polymyxin can induce resistance in KPN,highlighting the need for rational antibiotic use in clinical settings to delay the emergence of resistance.

Objective:To prospectively analyze the early clinical effects of 3D-printed porous metal cup with hip dual-mobility revision (HDR) system in treating severe acetabular bone defects.Methods:A total of 17 patients with severe acetabular defects (15 patients in Allan-Gross type 4 and 2 patients in type 5; 2 patients in Paprosky type 2B, 4 patients in type 3A and 11 patients in type 3B) who underwent revision hip arthroplasty between July 2019 and May 2020 were analyzed. There were 7 males and 10 females (mean age 67.3±9.3 years; range 42-80 years). The average body mass index was 22.2±3.8 kg/m 2 (range 17.7-33.3 kg/m 2). The preoperative mean leg length discrepancy (LLD) was 42.9±31.1 mm (range 10-160 mm) . One patient presented positive Trendelenburg sign. The follow-up duration was 12.1±3.0 months (range 6-16 months). The clinical and radiographic hip scores in all patients were evaluated. Results:The mean Harris Hip Score (HHS) was 31.2±11.3 points at preoperatively, 63.5±10.0, 68.7±10.4 and 70.2±10.1 points at 3 days, 7 days and 1 month postoperatively. At the latest follow-up, HHS was increased to 81.6±7.0 points. The outer cup mean abduction angle was 48.1°±10.6° and the mean inclination angle was 10.8°±6.0° postoperatively. The inner cup mean abduction angle was 45.0°±6.2° and the mean inclination angle was 10.8°±3.7°. The mean LLD decreased to 11.1±3.8 mm (range: 0-15 mm) after surgery. At the latest follow-up, all acetabular components were radiologically stable without displacement. No osteolysis or absorption was observed. There was no infection, loosening or nerve injury in all cases.Conclusion:During short-term follow-up, the 3D-printed porous metal HDR system can effectively enhance the stability of implants with satisfied quality of life. It can provide a good result for the revision of total hip arthroplasty with severe acetabular defects.

Objective To evaluate the efficacy and safety of non-steroidal anti-inflammatory drugs (NSAIDs) in preventing heterotopic ossification after hip arthroscopy.Methods Literature search was conducted in PubMed,Embase,Cochrane Library,CNKI and Wanfang data with time range from January 1973 to November 2017.Clinical case control articles on NSAIDs in preventing heterotopic ossification after hip arthroscopy were screened based on the inclusion and exclusion criteria.Meta analysis was done using RevMan 5.3 software to investigate the incidence of complications such as heterotopic ossification and gastrointestinal bleeding after hip arthroscopy in patients taking NSAIDs orally.Results Six articles were included in the study,with a total of 754 cases and 536 controls.NSAIDs reduced the incidence of heterotopic ossification after hip arthroscopy (RR =0.09,95％ CI 0.03-0.27,P ＜ 0.05).Selective COX-2 inhibitor celecoxib (RR =0.17,95％ CI 0.03-0.91,P ＜ 0.05) and PG synthase inhibitor of naproxen (RR =0.17,95％ CI 0.09-0.32,P ＜ 0.05) were also effective in preventing heterotopic ossification.There was no significant difference in the incidence of gastrointestinal complications between the cases and controls after NSAIDs prophylaxis (RR =2.17,95％ CI 0.92-5.12,P ＞ 0.05).Conclusion NSAIDs can effectively reduce the incidence of heterotopic ossification after hip arthroscopy and does not increase the incidence of postoperative gastrointestinal complications.Therefore,it is effective and safe to use NSAIDs to prevent the occurrence of heterotopic ossification after hip arthroscopy.

Objective To observe the outcome of uncemented hip arthroplasty for failed internal fixation of intertrochanteric fracture.Methods Seventeen patients admitted from Februaty 2010 to January 2014 were reviewed retrospectively in this study.The patients aged 67.2 years (range, 41-80 years) composed 6 males and 11 females.There were 15 patients with intertrochanteric fracture and 2 intertrochanteric and subtrochanteric fracture.The primary internal fixation method was dynamic hip screw (DHS) fixation in 2 patients, proximal femoral nail anti-rotation(PFNA) fixation in 12 patients and intramedullary nailing in 3 patients.Arthroplasty with a prosthetic hip was performed for 15 patients and with a prosthetic femoral head was done for 2 patients 3-48 months after the internal fixation.Harris score was used for evaluation of the results of hip arthroplasty.Preoperative Harris score was (32.6 ± 6.8)points.Results All the patients were followed up for 6 to 48 months.One patient with intraoperative femoral fracture experienced early subsidence and dislocation of femoral stem following allogeneic bone plate and titanium cable fixation and had further revision surgery.One patient had secondary subsidence of the femoral stem without pain and limitation of motion.One patient had primary infection recurrence after arthroplasty, but the infection remained uncured even after a series of treatments like repeated debridements, sustained vacuum drainage, prosthesis removal, debridement and temporary spacer implantation.Sixteen patients showed postoperative pain relief and good hip function recovery characterized by the ability to care for themselves and no prosthetic loosening.Harris hip score signficantly improved to (79.2 ± 15.9) points at the final follow-up (P ＜ 0.01).Conclusions Uncemented hip arthroplasty is an effective method for the failed internal fixation of peritrochanteric fracture.The procedure achieves satisfactory function recovery, early weight-bearing exercise and early recovery of self-care ability,and avoids the complications of bone cement use.