Objective:To construct and identify the monoclonal antibody of ATP synthase beta subunit (ATP5B) with high purity, and to lay foundation for further study.Methods:The ATP5Bgene was amplified by PCR and cloned into the pET28avector and transformed into E.coli BL21 (DE3) .The protein expression was induced by IPTG and then the fusion protein was purified by nickel affinity chromatography column.The protein purity was detected by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) .Three female Balb/C mice were immunized with purified fusion protein and the tail vein blood was taken to detect the titer of ATP5Bantibody by indirect enzyme-linked immunosorbent assay (ELISA) .The spleen cells from the immunized mice with the highest serum titer were mixed with the SP2/0cells to establish the hybridoma cells and the fused cells were screened by indirect ELISA and monoclonally cultured.Karyotype analysis were performed in the positive cells.The hybridoma cells were intraperitoneally injected into 12weeks old BALB/C mice to estabilish the ascites models.The titer of ascites was detected by indirect ELISA.The purity of the antibody was detected by SDS-PAGE.The antibody subtype was detected by ELISA.Results:After PCR amplification, a specific band of 1 455bp was obtained, and the pET28aempty vector was ligated to obtain a recombinant pET28a/ATP5Bvector.The target protein was expressed in the IPTG-induced bacteria solution;the SDS-PAGE results showed that the protein band was found at51 000.The indirect ELISA results showed that the serum titer of the venous blood of immunized mice was up to1:64 000.In karyotype analysis, the total number of chromosomes in hybridoma cells was about the sum of myeloma cells and normal mouse spleen cells.The mouse ascites was prepared with the hybridoma cell line, and the highest titer of the antibody was 1:240 000.The subtype of the monoclonal antibody produced by the hybridoma cells was IgG1.Conclusion:The monoclonal antibody against ATP5Bprotein is successfully prepared by cloning, expressing and purifying the recombinant protein.

Objective To study the correlation of whole brain apparent diffusion coefficient (ADC) with neurological impairment,homocysteine (Hcy) metabolism and oxygen free radical generation in patients with Alzheimer's disease (AD).Methods The patients diagnosed as AD in Xuanwu Hospital of Capital Medical University from March 2014 to December 2017 were selected as AD group and healthy persons as control group.The ADC of whole brain was calculated after magnetic resonance scanning.The degree of neurological impairment was evaluated by Montreal Cognitive Function Assessment Scale (MoCA).The levels of Hcy metabolic index and oxygen free radical production were measured after collecting serum.Results ADC values of AD group in parietal lobe,frontal lobe,temporal lobe and occipital lobe were not significantly different from those of control group (P ＞ 0.05).The ADC value of hippocampus as well as serum Hcy,malondialdehyde (MDA) and nitric oxide (NO) contents were significantly higher than those of control group,while MoCA score as well as folic acid (FA),vitamin B12 (VitB12),superoxide dismutase (SOD) and glutathione peroxidase (GSH) contents in serum were significantly lower than those of control group (P ＜ 0.05);ADC value of hippocampus in AD patients was negatively correlated with MoCA score as well as serum FA,VitB12,SOD and GSH contents,and positively correlated with serum Hcy,MDA and NO contents.Conclusions The increased ADC value of hippocampus in AD patients was related to the cognitive function injury,Hcy metabolism disorder and excessive generation of oxygen free radicals.

Chondroitin sulfate (CS) is a sulfurated glycosaminoglycan, a major component of the extracellular matrix, widely distributed in skin, cartilage and vascular tissue. CS plays an important role in the physiological state regulation of articular cartilage, which affects tensile strength and elasticity of tissues by influencing aggrecan. Previous studies have shown that CS sulfate modification may be related to the growth and development disorders of cartilage tissue and the occurrence of osteoarticular diseases. At the same time, CS is also a common joint supplement, often used in the treatment of osteoarthritis and Kashin-Beck disease. In this paper, the research progress of CS sulfate modification characteristics in Kashin-Beck disease and osteoarthritis and the application of the preparation in the treatment of Kashin-Beck disease and osteoarthritis are reviewed, aiming to provide help for the investigation of the etiology of Kashin-Beck disease and the treatment of osteoarthritis and Kashin-Beck disease.

Objective:To investigate the value of plasma Epstein-Barr virus (EBV) DNA detection in the screening of nasopharyngeal carcinoma (NPC) and its clinical application in non-high-risk areas.Methods:Plasma EBV DNA results in 1 153 newly diagnosed nasopharyngeal carcinoma patients who were treated in Sichuan Cancer Hospital from 2015 to 2020 and 244 healthy control cases with matched sex and age were retrospectively analyzed. EBV DNA were detected by quantitative real-time PCR. Positive rate of EBV DNA was determined by the cutoff value of 400 (≥400 copies/ml as positive) and optimization threshold method (presence of S amplification curve as positive). Further analyses were conducted to compare EBV DNA load in different clinical stage, TNM stage and regions distribution characteristics. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of the cutoff value of 400 and optimization threshold method for NPC.Results:Compared with healthy controls, EBV DNA increased significantly in newly diagnosed NPC patients ( P<0.001). Both evaluation methods revealed that the EBV DNA positive percentage increased with TNM and clinical stage ( P<0.001). With 400 copies/ml as cutoff value, the diagnostic sensitivity and specificity were 40.85% and 100%, respectively. The area under the curve was 0.704 (95% CI 0.676-0.733, P<0.001). Evaluated by the optimization threshold method, the sensitivity and specificity could improve to 82.0% and 99.2%, respectively, and the area under the curve reached 0.910 (95% CI 0.894-0.924, P<0.001). Conclusions:In the low prevalence area of nasopharyngeal carcinoma, the sensitivity for diagnosis of nasopharyngeal carcinoma is only 40.9% by the 400 copies/ml cutoff value method. The optimization threshold method is a better choice to improve the diagnostic sensitivity without lowering the diagnostic specificity.

This paper reviews the status quo of recent years’ research on autophagy and damage of chondrocytes in Kashin-Beck disease （KBD） and osteoarthritis （OA）. PI3K/AKT signaling pathway and mTOR regulate the autophagy activity of chondrocytes. PI3K/AKT signaling pathway can promote the proliferation of chondrocytes and cause their damage by inhibiting their autophagy activity. This might play an important role in the occurrence and progression of bone and joint diseases such as KBD and OA， and provide scientific basis for revealing the pathogenesis and treatment plan of them.