[ ABSTRACT] AIM:To investigate the cardiac AMP-activated protein kinase ( AMPK) activity and the effects of AMPK activator on cardiac structure and function in the mice with different β-adrenoceptor (β-AR) stimulation patterns . METHODS:Male BALB/c mice were subcutaneously injected with AMPK activator ( AICAR, 250 mg· kg -1 · d-1 ) or saline, and infused with β-AR agonist isoproterenol (ISO, 5 mg· kg-1· d-1) for 14 d.The cardiac functions were evalu-ated by echocardiography or hemodynamic method , and the hearts were harvested after infusion cessation immediately or 3 d later.Phosphorylated AMPK ( p-AMPK) was measured by Western blot .RESULTS:Sustained ISO infusion increased p-AMPK level.AICAR did not further increase p-AMPK but attenuated ISO-induced increase in heart weight .Sustained ISO infusion increased cardiac systolic function as indicated by left ventricular fractional shortening ( FS) and maximum rate of pressure rise (+dp/dtmax).The cardiac systolic function was not further increased by AICAR .The cardiac diastolic func-tion as indicated by left ventricular end-diastolic pressure (LVEDP) was not different in each group .In contrast, cardiac p-AMPK level was similar between the control mice and the mice with sustained ISO infusion and ceased infusion for 3 d. In this model, AICAR improved the cardiac systolic and diastolic functions , which were impaired by ISO.Moreover, the increased pattern of p-AMPK level was similar with that of heart rate upon ISO stimulation .CONCLUSION: Sustained ISO infusion increases p-AMPK.After ISO infusion cessation for 3 d, p-AMPK is decreased to the basal level .β-AR-in-duced inotropic effects should be avoided to investigate the cardioprotective role of AMPK activation in the β-AR stimulation models.

Objective To investigate the distribution and incidence of hyperuricemia for the Zhoushan island residents in Zhe-jiang province and provide scientific advice for health management.Methods The uric acid reports of island residents were analyzed by a retrospective statistical analysis in the Physical Examination Center of the 413 Hospital from October 2013 to October 2015.The patients with metabolic diseases (such as diabetes,chronic renal failure and other people,etc.)were ex-cluded.According to the different gender and different age groups,the average level of uric acid,hyperuricemia occurrence rate and the difference among the groups were performed statistical analyses.The single factor analysis of variance was used by Microsoft 2003 Excel software.Results The average serum uric acid level of 7 310 island residents was 283±82μmol/L and the incidence of hyperuricemia was 21.2%.The incidence of hyperuricemia was 33.6% in 31~40 years group,and the average level of uric acid was 343±86μmol/L and significantly higher than≤30 years group,significant statistic difference were observed.The incidence of hyperuricemia was more than 15% in≥41 years group,significantly higher than≤30 years group.The population of physical examination was concentrated in the 31~40 years group.The hyperuricemia incidence was 27.9% in 5 214 male residents,and the average serum uric acid level was 368±74μmol/L and higher than the female group (P<0.001).The hyperuricemia incidence was as high as 43.1% in 31~40 years group.But the level of average serum uric acid showed no significant difference with≤30 years group(P>0.05).The level of average serum uric acid level was less in≥61 and 41~50 years group than in ≤30 years group (P<0.05),but the hyperuricemia incidence were higher than ≤30 years group.The incidence of hyperuricemia was 4.6% in 2 096 female residents.The level of average serum uric acid was 257±57μmol/L and lower than the male group in all age groups (P<0.001).The incidence of hyperuricemia was 18.6% in≥60 years old and lower than 10% in the other groups.The incidence of hyperuricemia increased gradually with age.Conclu-sion The hyperuricemia incidence in island residents was higher,and higher in male than in female.The occurrence of hype-ruricemia was significantly younger.Therefore,health education,reasonable diet adj ustment,improvement of lifestyle and eating habits etc.Should be conducted for a long time to prevent the occurrence of hyperuricemia and related diseases.

Objective:To investigate the correlation between the osseous structure of temporomandibular joint (TMJ) and three different status of anterior disc location, so that it could guide the clinical diagnosis further.Methods:Fifty-two patients [46 females and 6 males, with an age of (27.8±8.3) years] who treated with MRI and cone beam CT, were recruited from the Temporomandibular Joint Specialist Clinic, The First Affiliated Hospital of Xinjiang Medical University, between March 2018 to December 2021. According to the radiographic findings of the level of anterior disc displacement (ADD) in TMJ, patients were divided into three groups: normal articular disc position (NADP, n=28 TMJs), anterior disc displacement with reduction (ADDWR, n=28 TMJs), and anterior disc displacement without reduction (ADDWoR, n=28 TMJs). In the light of the reconstructed three-dimensional model, ten representative morphological parameters including condylar volume (CV), condylar superficial area (CSA), fossa volume (FV), fossa superficial area (FSA), the proportion of the condylar volume in the articular fossa (CV%), the proportion of the condylar superficial area in the articular fossa (CSA%), superior joint space (SJS), anterior joint space (AJS), posterior joint space (PJS), and medial joint space (MJS), were measured respectively under one-way analysis of variance (ANOVA), Kruskal-Wallis Htest and receiver operator characteristic curve(ROC curve) analyses. Results:CV and CSA values varied significantly in the pathological progression from normal location to irreversible anterior displacement in TMJ. For CV value, NADP group [(1 834.90±667.67) mm 3]>ADDWR group [(1 747.34±369.42) mm 3]>ADDWoR group [(1 256.29±418.27) mm 3] [ t=4.31, P(NADP-ADDWoR)<0.001; t=3.66, P(ADDWR-ADDWoR)<0.001], for CSA value, NADP group [(859.27±216.01) mm 2]>ADDWR group [(838.23±118.82) mm 2]>ADDWoR group [(669.14±150.26) mm 2] [ t=4.27, P(NADP-ADDWoR)<0.001; t=3.80, P(ADDWR-ADDWoR)<0.001]. The difference of SJS value in NADP group [(2.22±0.88) mm], ADDWR group [(1.94±0.64) mm] and ADDWoR group [(1.45±0.57) mm], was statistically significant [ t=4.11, P(NADP-ADDWoR)<0.001; t=2.63, P(ADDWR-ADDWoR)=0.010]. The results of MJS in NADP group [(5.03±1.41) mm], ADDWR group [(3.86±1.32) mm], and ADDWoR group [(4.91±1.65) mm] were significantly different [ t=3.00, P(NADP-ADDWR)=0.004; t=2.63, P(ADDWR-ADDWoR)=0.009]. As calculated by the ROC curve analysis, CV, CSA and SJS showed that (AUC CV=0.77, AUC CSA=0.76; AUC SJS=0.76) for the NADP and ADDWoR groups, and (AUC CV=0.80; AUC CSA=0.80; AUC SJS=0.72) for the ADDWR and ADDWoR groups. While the diagnostic accuracy of MJS for the comparison in NADP versus ADDWR and ADDWR versus ADDWoR was respectively AUC (NADP-ADDWR)=0.73, and AUC (ADDWR-ADDWoR)=0.69. Conclusions:CV, CSA, SJS, and MJS were significantly associated with the different disc displacement status, and the condyle in TMJ ADD exhibited three-dimensionally altered dimensions. They could be considered as promising biometric markers to diagnose the ADD status.

Objective To investigate the effect of fluid flow shear stress(FFSS)on the fluid mechanic threshold of high-mobility group box 1(HMGB1)release by synovial cells and chondrocytes.Moreover,the mechanism of chondro-cyte and synovial cell damage induced by abnormal mechanical force was investigated to provide an experimental basis for exploring the pathogenesis and pathology of temporomandibular joint osteoarthritis.Methods With the approval of the Ethics Committee for Animal Experiments of the hospital,synovial tissue and cartilage tissue blocks were obtained from the knee joints of Sprague-Dawley(SD)rats,and synovial cells and chondrocytes were cultured and digested for subsequent experiments.Synovial cells and chondrocytes of 3-4 generations were acquired,and FFSS was applied to sy-novial and cartilage cells using a fluid shear mechanical device.The cells were divided according to the FFSS values of different sizes.Synovial cells were stimulated for 1 h with 1,3,5,or 10 dyn/cm2 of FFSS,and chondrocytes were stimu-lated for 1 h with 4,8,12,or 16 dyn/cm2 of FFSS.Resting cultures(0 dyn/cm2)were used as the control group.Changes in the morphology of the cells were observed.The expression and distribution of HMGB1 and interleukin-1β(IL-1β)were observed by immunohistochemistry.The expression of HMGB1 and IL-1β in the supernatant was analyzed by ELI-SA.The protein expression levels of intracellular HMGB1 and IL-1β were detected by Western blot.Results With in-creasing FFSS,the synovial cells and chondrocytes gradually swelled and ruptured,and the number of cells decreased.With increasing FFSS,the localizationof HMGB1 and IL-1β gradually shifted from the nucleus to the cytoplasm.In synovial cells,compared with those in the control group,the expression levels of HMGB1 and IL-1β were increased both in the supernatant and cells in the 1,3,5 and 10 dyn/cm2 intervention groups(P＜0.01).In chondrocytes,com-pared with those in the control group,the expression levels of HMGB1 in the supernatant were increased in the 4,12 and 16 dyn/cm2 intervention groups(P＜0.05),and the protein expression levels of HMGB1 were significantly increased(P＜0.01).The expression levels of HMGB1 in the supernatant were significantly increased in the 8 dyn/cm2 intervention groups(P＜0.01);however,the protein expression levels of HMGB1 were significantly decreased.Compared with those in the control group,the expression levels of IL-1β in the supernatant gradually increased in the 4,8,12 and 16 dyn/cm2 intervention groups(P＜0.01).With the exception of those in the 4 dyn/cm2 group,the protein expression levels of IL-1β gradually increased with increasing FFSS(P＜0.05).Conclusion With increasing FFSS,synovial cells and chondro-cytes gradually swelled and burst,and the hydromechanical thresholds of HMGB1 release were 1 dyn/cm2 and 8 dyn/cm2,respectively.Therefore,upon stimulation with a mechanical force,synovial damage was damaged before chondrocytes.