Objective To analyze the difference between primary biliary cirrhosis (PBC) and primary Sj(o)gren's syndrome (pSS) and primary biliary cirrhosis complicating with Sj(o)gren's syndrome (SS) in clinical features,anti-60 000 SSA multiple antigenic peptides (MAPs) detection rate,and explore the potential mechanisms of PBC with SS.Methods MAPs were artificially synthesized.Enzyme-linked immunosorbent assay (ELISA) was done to detect anti-MAPs antibodies in the sera of the three groups of patients.The detection rates of anti-MAPs antibodies were compared among groups and the relations of anti-MAPs antibodies with clinical features were analyzed.Chi-square test,Fisher's exact test,t test or Wilcoxon signed rank test were conducted in this study.Results There was no significant difference in clinical features,liver function tests and antibody profiles between PBC and PBC with SS.Significant difference of anti-MAP20 antibody detection rote was detected between pSS and PBC with SS groups [25％(7/28) vs 0(0/25),x2=7.201 1,P=0.007 3],and anti-MAP3,7 and 17 antibody detection rates in PBC with SS patients [4％(1/25),4％(1/25),8％(2/25)] were similar to pSS [4％(1/28),7％(2/28),7％(2/28)].The anti-MAP7 antibody and anti-MAP12 antibody detection rates were significantly higher in patients with splenomegaly than patients without splenomegaly [38％(3/8) vs 2％(2/84),38％(3/8) vs 4％(3/84); P=0.039 4,P=0.039 4],while the antiMAP17 antibody detection rate was significantly lower in patients with salivary gland injury than patients without salivary gland injury [5％(3/64) vs 39％(5/13); x2=4.431 8,P=0.035 3].Conclusion There is significant difference in the anti-MAPs detection rates among the three patients groups,and the detection rate may be higher in patients with certain clinical manifestations.

BACKGROUND:Pulsed electromagnetic fields,as an important physical therapy,are exactly effective in the treatment of osteoarthritis,but the mechanism has not been fully clarified. OBJECTIVE:To observe the effect of pulsed electromagnetic field on the degeneration of knee joint cartilage in aged rats. METHODS:Eight 6-month-old Sprague-Dawley rats were selected as the young group and were subjected to normal diet with no treatment.Sixteen 22-month-old Sprague-Dawley rats were randomly divided into old group(n=8)and pulsed electromagnetic field group(n=8).The rats in the pulsed electromagnetic field group were subjected to a pulsed electromagnetic field intervention,once a day,5 days per week for continuous 8 weeks.The rats in the old group were given no treatment.All rats were anesthetized and executed after 8 weeks for the detection of relevant indexes. RESULTS AND CONCLUSION:Compared with the young group,serum type Ⅱ collagen C-terminal peptide level was increased in the old group(P<0.05);compared with the old group,serum type Ⅱ collagen C-terminal peptide level was decreased in the pulsed electromagnetic field group(P<0.05).Micro-CT showed that the bone volume fraction,bone mineral density,and number of bone trabeculae decreased(P<0.05)and the trabecular separation increased(P<0.05)in the tibia of rats in the aged group compared with the young group;and the bone volume fraction,bone density,and number of trabeculae increased(P<0.05)and the trabecular separation decreased(P<0.05)in the tibia of rats in the pulsed electromagnetic field group compared with the aged group.The tibial plateau Safranin O-fast green staining showed that the articular cartilage structure of rats in the aged group was disorganized,and the number of chondrocytes was obviously reduced,and the tidal line could not be distinguished.The above results were improved in the pulsed electromagnetic field group.RT-qPCR and western blot assay showed that the mRNA and protein expression levels of matrix metalloproteinase 1,matrix metalloproteinase 13,P53 and P21 in the articular cartilage and subchondral bone of rats were elevated in the aged group compared with the young group(P<0.05)and decreased in the pulsed electromagnetic field group compared with the old group(P<0.05).To conclude,pulsed electromagnetic fields may improve osteoarthritis in aged rats by inhibiting chondrocyte senescence,alleviating articular cartilage degradation and inhibiting subchondral bone osteoporosis through suppressing the expression of P53/P21.