Objective To establish a real-time quantitative polymerase chain reaction (qPCR) assay for B-cell lymphoblastic leukemia according to individualized and specific immunoglobulin gene rearrangements in leukemia cells, and to use it for the monitoring of minimal residual disease (MRD) of B-cell lymphocytic leukemia. Methods The immunoglobulin gene rearrangements of bone marrow samples from 15 cases of B-cell lymphoblastic leukemia were analyzed with a validated European BIOMED-2 system, and the individualized and specific qPCR-based quantification of leukemic immunoglobulin gene rearrangements was established. Results Unique and specific gene rearrangements of immunoglobulin light and heavy chains were identified in 14 cases and Ig-qPCR based on these gene rearrangements had a sensitivity of 10-5 and high specificity which met the international criteria in 10 patients. Leukemia MRD quantification with immunoglobulin gene rearrangement-based qPCR was similar as compared with other MRD detection methods. Conclusion Immunoglobulin gene rearrangement-based leukemia MRD quantification is feasible, sensitive, specific, precise and much valuable for clinical decision of treatments in B-cell lymphoblastic leukemia.

Objective The purpose of this study is to compare the wear properties of UHMWPE acetabular liners after undergoing 3 million(3 Mc)and 5 million(5 Mc)cycles of in-vitro wear testing.The results will serve as a reference for the design of in-vitro testing for hip prostheses and as a control for clinical revision removals.Methods Wear tests were conducted on three different sizes of acetabular liners(28 mm,32 mm,and 36 mm internal diameters)using a hip simulator to determine the amount of wear after 3 and 5 million cycles.The analysis included the number,size,and shape of abrasive particles.Results After 3 and 5 million cycles of wear,the amount of wear on the acetabular liner increased as the inner diameter increased.The abrasive particles had an average equivalent circular area diameter(ECD)of 0.27 μm and 0.29 μm,and 94.4%and 90.1%of the aspect ratio(AR)less than 4.Conclusion The amount of wear on the acetabular liner after 3 Mc wear can indicate the wear performance of the product.The number of particles increased and the percentage of fibrous particles was higher after 5 Mc wear compared to 3 Mc wear.

In vitro wear tests were conducted on knee tibial liner manufactured from a new highly cross-linked polyethylene material(XLPE-DG)with dodecyl gallate.The characteristics(quantity,size and shape)of wear mass loss(wear volume),wear rate and wear particles were studied,and the wear performance in different wear stages was analyzed,so as to provide data support for the research and development and clinical application of domestic medical polyethylene materials.In accordance with the International Organization for Standardization(ISO)14243-1 and 14243-2 standard methods,4 total knee arthroplasty prostheses were selected as test samples(3 in the test group and 1 in the control group).The lubricant in the test was calf serum,and the XLPE-DG liner was tested for cyclic wear using a knee joint simulator.The wear volume and the wear rate after 1 million cycles(1 Mc),3 million cycles(3 Mc),and 5 million cycles(5 Mc)were calculated respectively.The abrasive debris images obtained by the scanning electron microscope(SEM)was analyzed by using image analysis software to analyze the characteristics of the debris of the wear debris(number,size and shape).After passing the 5 Mc wear test,the wear amount of XLPE-DG liner was(23.86±0.75)mg,with a corresponding wear rate of(4.39±0.75)mg/Mc and the wear amount during the 3-5 Mc stage was similar to that of the 1-3 Mc stage(8.79 mg vs.8.74 mg).The number of wear debris decreased with the increase of the number of wear times.The average value of the equivalent circular area diameter(ECD)of the wear debris of XLPE-DG liner after 5 Mc was 0.13 μm(minimum value 0.04 μm,maximum value 0.8 μm),and the average ECD of 77.11%±6.89%particles was<0.2 μm,the average value of ECD decreased with the increase of the number of wear times.The average value of the aspect ratio(AR)of the liner after 5 Mc wear was 2.8(minimum 1.0,maximum 9.9),of which 77.9%had an AR value of<4 and the particles are mainly round.The XLPE-DG liner demonstrated excellent wear resistance and can reduce the risk of periprosthetic inflammation,osteolysis,and prosthetic loosening in clinical applications,and have good clinical application potential.

Objective To analyze coating properties of porous artificial joints,including coating morphology and coating mechanical properties,and summarize the range of coating properties of current mainstream products,to provide references for the design and development of new products,as well as provide the basis for the long-term implant removal analysis.Methods Samples for the surface morphology,shear strength,and tensile strength of the coatings used in the experiment were prepared in accordance with ASTM F1854,ASTM F1044,and ASTM F1 147 standards,respectively.The coatings were processed using plasma spraying.The surface morphology(coating thickness,porosity,and pore intercept)of the coatings for all 17 products(Nos.1-17)was tested;for products Nos.1-7 and Nos.15-16,the shear strength test between the coating and substrate was conducted first in accordance with the test method of ASTM F1044.Then,according to the test method of ASTM F1 147,the tensile strength test between the coating and substrate was conducted.For product No.17,the shear and tensile strengths of the composite coating and simple titanium coating were tested,respectively,according to the test method of ASTM F1044 and ASTM F1 147.Results A total of 15 products(88.2％)had coating thicknesses between 300 μm and 500 μm.There were 16 metal-coated products(Nos.1-16),of which 11(68.75％of the total)had coating porosities between 30％and 50％,and 14(87.5％of the total)had coating pore intercepts between 50 μm and 150 μm.The mechanical properties of the coatings were independent of the substrate material used.The shear and tensile strengths of the composite coatings with hydroxyaptite(HA)were significantly lower than those of the pure metal coatings.Conclusions For the design and manufacture of artificial joints with porous coatings,the performance of the coating can be referred to the following indexes:the coating thickness is 300-500 μm,the coating porosity is 30％-50％,the coating pore intercept is 50-150 μm.The substrate materials can be selected based on the use of the product.The effects of a lower bonding force on product performance should be considered when designing prostheses with composite coatings containing HA.This range of performance metrics provides control for long-term clinical extraction analyses.

Objective:To study the patterns of tocilizumab (TCZ) use, its efficacy and safety in patients with rheumatoid arthritis (RA) in routine clinical practice.Methods:A total of 407 patients with RA were enrolled from 23 centers and treated with TCZ within 8 weeks prior to the enrollment visit, and were followed for 6-month. The patterns of TCZ treatment at 6 months, the effectiveness and safety outcomes were recorded. Statistical analysis was performed using SAS version 9.4.Results:A total of 396 patients were included for analysis, in which 330 (83.3%) patients received TCZ combined with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), and 16.7%(66/396) received TCZ monotherapy. At baseline, TCZ was initiated in 56.6%(224/396) and 9.6%(38/396) of patients after failure of DMARDs and other biological agents (bDMARDs) respectively. During the 6-month follow-up period, the mean frequency of TCZ administration was (3.7±1.6), the mean TCZ dosage was (7.4±1.2) mg/kg, and the mean interval between doses was (40±13) days. 120(25.8%) patients were on TCZ treatment at the end of the study. Improvements in disease activity, systemic symptoms and patient report outcomes were observed at the end of the study. 22.7%(90/396) patients experienced at least one treatment related adverse event, and 8 patients experienced at least one serious adverse event.Conclusion:This study demonstrates that TCZ treatment is effective in patients with RA when being treated for 6 months with an acceptable safety profile. The duration of TCZ treatment needs to be extended.