BACKGROUND: Ultra-high molecular weight polyethylene (UHMWPE) is widely used as acetabulum. The hip joint will produce lots of grind particles and lead to loosening of artificial joint because of alternating load and bad lubricate condition.OBJECTIVE: To learn about the lubricate mechanism of joint, introduce the present situation on artificial hip joint of UHMWPE including wear behavior and wear resistance properties, and grope for scientific evaluate method of tribological properties in artificial joints.RETRIEVAL STRATEGY: The articles published between January 2000 and October 2007 were searched by using computer with the key terms "hip joint, ultra-high molecular weight polyethylene, tribology" in CNKI, Weipu Science and Technology Database, Wanfang Database, and its language was limited to Chinese. Meanwhile, the English articles were searched in IEEE/IEE Electronic Library and Elsevier Electronic Journal Database with the key terms "hip simulators, ultra-high molecular weight polyethylene, tribology ". Those referring to the friction and wear property of the joints were included, whereas repeated researches were deleted.LITERATURE EVALUATION: Totally 729 articles were received. After the primary screening of the titles and abstracts, 601 repeated or similar researches were excluded, and other 128 articles were adopted for further analysis, finally 22 articles in accordance with the inclusion criteria were included as references.DATA SYNTHESIS: The study about UHMWPE focused two points, one is surface modification, the other is wear and friction mechanism.①The study indicates that wear properties of UHMWPE can be improved by surface modification, such as ion implantation and nanometer padding have a remarkable elevating ability of the wear and mechanical properties.②At recent years, scholars do many basal experiences about the tribology of hip joints, and have approved that wear rate of friction pairs would reduce under biological lubricate condition using artificial joint simulators or traditional tester in various conditions.CONCLUSION: The study about hip joint in China drops behind the developed counties, this traditional method can not really reflect wear and friction properties in vivo. Therefore, the following research should include making clear the relationships of load, environmental condition and wear of artificial joint in vivo, as well as groping for a scientific evaluate method of tribological properties in hip joints.

Objective To investigate a convenient and quantitative solution to activation levels and functional characterization of CAR-T cells by inserting T cell activity-responsive promoter (TARP) nanoluciferase reporter gene system into a lentiviral plasmid containing the gene encoding the chimeric antigen receptor (CAR). Methods The recombinant plasmid was constructed by using whole gene synthesis and molecular cloning techniques. The lentivirus was packaged and was infected with human primary T lymphocytes. Flow cytometry was used to detected the positive rate of lentivirus-infected T cells. The functional characterization of CAR-T cells was identified by luciferase reporter gene system, Western blot, flow cytometry, and small animal live imaging techniques. Results The results of enzyme digestion identification and the plasmid sequencing showed that the recombinant plasmids were constructed, and flow cytometry displayed the normal preparation of CAR-T cells. This system could dynamically respond to the activation of CAR-T cells by luciferase reporter gene system. The functional assay in vitro confirmed that the system could reflect the exhaustion of CAR-T cells, and the small animal live imaging results demonstrated that the system can be used as a tracer of CAR-T cells in mice. Conclusion TARP nanoluciferase reporter gene system provides a more convenient, sensitive and quantitative method for evaluating CAR-T cells activation level, exhaustion phenotype and tracing.
Humans ; Animals ; Mice ; T-Lymphocytes ; Cell Line, Tumor ; Receptors, Chimeric Antigen/genetics* ; Promoter Regions, Genetic ; Immunotherapy, Adoptive/methods*