ObjectiveTo investigate the expression levels of vascular endothelial growth factor (VEGF)in knee synovial membranes and synovial fluids whether it could be a marker for progressive osteoarthritis.MethodsKnee synovial membranes and synovial fluids of patients with osteoarthritis who were underwent total knee arthroplaaty or arthroscopy were collected. They were classified into four groups according to the radiographic grading[Kellegren-Lawrence(K-L) grade]. Appoint K-L-0-grade patients who suffered from menisci injuries only served as controls. The levels of VEGF in the synovial fluid were measured by enzymelinked immunosorbent assay(ELISA) and VEGF-secreting cells were identified by immunohistochemistry.ANOVA was used for statistical analysis. ResultsVarious degrees of inflammation could be found in all the samplesevaluated histologically on HE-stained sections. Synovial tissue inflammation presented as synovial lining thickening, and inflammatory cells infiltration. VEGF expressed in the synovium linings and surrounding blood vessels. The VEGF levels in the synovial fluids were increased accordingly with K-L grades, which reached the peak level in the late stage of osteoarthritis. The levels of VEGF in the synovial fluids were significantly higher in patients with osteoarthritis[from (1181±116), (1632±140) to (2252±216) pg/ml]than in those with menisci injury (P＜0.01); The percent ages positive cell in each groups were (5±4)％ , (9±4)％,(16±6)％ and (21±6)％ respectively, there were significantly differences too (P＜0.01). ConclusionVEGF originated from synovial tissue may play a role in the pathogenesis of osteoarthritis. High levels of VEGF in the synovial fluids can be regarded as the marker of active osteoarthritis.

Objective:To establish risk stratifying criteria for acute rejection(AR)after kidney transplantation(KT)through analyzing the preoperative risk factors of KT recipients from deceased donor(DD).Methods:A retrospective study is conducted for 1 382 KT recipients of DD kidney at First Affiliated Hospital of Xi'an Jiaotong University from January 2015 to December 2020.According to the presence or absence of AR within 1 year post-KT, they are divided into two groups of acute rejection(group AR, 115 cases)and non-rejection(group non-AR, 1 267 cases). Clinical data of two groups are examined by univariate and multivariate analyses for determining the risk factors of AR and a scoring standard is established on the basis of regression coefficients.They are divided into three groups of low-risk(907 cases), middle-risk(450 cases)and high-risk(25 cases)according to the scoring results and the incidence of AR is compared among different scoring groups.Results:Univariate analysis indicates that donor age(AR, 793 cases; non-AR, 474 cases, P=0.033), age difference between recipients and donors≥25 years(AR, 63 cases; non-AR; 315 cases; P<0.001), recipient panel-reactive antibodies(PRA)plus donor-specific antibody(DSA)(+ )(AR, 96 cases; non-AR, 1 169 cases, P=0.002), donor kidney cold ischemic time≥12h(AR, 81 cases; non-AR, 1 064 cases, P<0.001), donor/recipient HLA mismatch≥3(AR, 70 cases; non-AR, 984 cases, P<0.001)and expanded criteria donor(ECD)(AR, 50 cases; non-AR, 790 cases, P<0.001)are high risk factors for AR(all P<0.05). Variables with statistical significance during univariate analysis are included for multivariate analysis.Five variables are finally determined, including age difference between recipients and donors≥25 years(β=0.61, P=0.006), PRA+ DSA(+ )(β=0.74, P=0.008), donor kidney cold ischemic time≥12 h(β=0.74, P<0.001), HLA mismatch(≥3)(β=0.81, P<0.001)and ECD(β=0.82, P<0.001). Score for each risk factor is calculated according to the relevant regression coefficient and scoring standard formulate on the basis of the above five risk factors with a total score of 36.With an overall incidence of AR at 8.32%(115/1 382), the incidence of AR is 4.3%, 14.7% and 40.0% in low/middle/high-risk group and the difference is statistically significant.It hints that immune risk stratification can effectively determine the risk of postoperative AR for KT recipients.The incidence of AR is significantly higher in middle/high-risk group than that in low-risk group ( P<0.001). Conclusions:For recipients with middle/high immune risk, intensity and dose of immunosuppressants should be appropriately boosted during preoperative induction and maintenance period.And the occurrences of AR and infection should be dynamically monitored.

In this study, the mature peptide sequence of a pectin lyase gene A was amplified from Aspergillus niger strain EIM-6 by using RT-PCR reverse transcription technique. The cloned gene was then inserted into a Pichia pastoris expression vector pPIC9k to produce the recombinant expression plasmid pPIC9K-pelA. By using electric shocks, we successfully transformed the recombinant pPIC9K-pelA into Pichia pastoris GS115. The activity of the engineered strain reached to 2.3 U/mL after induction with the final concentration of 1.5% methanol. SDS-PAGE analysis revealed that the pPIC9K-pelA transformant had an additional protein band of approximately 38 kD, which was not present in the control. There were no significant differences between the recombinant and native pectin lyase with regard to their hydrolysis activities.
Aspergillus niger ; enzymology ; genetics ; Electroporation ; Pichia ; genetics ; metabolism ; Polysaccharide-Lyases ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction