Objective To investigate the longitudinal changes in left ventricular(LV)structure and function after bariatric surgery in obese individuals and their relationship with preoperative left ventricular ejection fraction(LVEF)by cardiac magnetic resonance(CMR)imaging.Methods We prospectively enrolled 75 obese subjects scheduled for laparoscopic sleeve gastrectomy and 46 age and sex-matched healthy controls(the control group).All subjects underwent CMR examination to obtain LV structural parameters,LVEF,and strain parameters.According to their preoperative LVEF,the obese subjects were divided into two obesity groups,including the group of patients with LVEF≥60％(n=43)and the group of patients with 50％≤LVEF＜60％(n=32).LV structural and functional differences between the control group and the two obesity groups were compared.Eventually,38 obese subjects completed the CMR follow-up at 1 month and 12 months after bariatric surgery.The longitudinal changes in LV structure and function after surgery in the LVEF ≥ 60％(n=20)group and the 50％≤LVEF＜60％group(n=18)were compared.Results Before bariatric surgery,the global longitudinal strain was significantly lower in the LVEF ≥ 60％group than that in the control group([-18.36±1.86]％vs.[-19.50±1.53]％,P＜0.05).The global radial([27.70±3.52]％vs.[34.44±4.11]％,P＜0.05),circumferential([-17.35±1.46]％vs.[-19.85±1.42]％,P＜0.05),and longitudinal([-16.22±1.81]％vs.[-19.50±1.53]％,P＜0.05)strain in the 50％≤ LVEF＜60％group was significantly lower than that in the control group.At 12 months after bariatric surgery,the global radial([32.52±7.84]％vs.[30.92±4.27]％,P＞0.05),circumferential([-19.02±2.42]％vs.[-18.63±1.49]％,P＞0.05),and longitudinal([-18.18±2.06]％vs.[-17.78±1.66]％,P＞0.05)strain in the LVEF≥60％group showed no significant difference compared with the baseline findings.In the 50％≤ LVEF＜60％group,the global radial([32.73±5.86]％vs.[26.83±4.85]％,P＜0.05)and circumferential([-19.10±2.00]％vs.[-16.91±2.09]％,P＜0.05)strain was significantly higher than that before surgery.Conclusion LV remodeling is reversed after bariatric surgery in obese subjects,and the longitudinal changes in LV structure and function vary with the preoperative LVEF.

OBJECTIVE To establish a method for simultaneous determi nation of six components in Melastoma dodecandrum and investigate its correlation with antioxidant activity. METHODS Ultra high-performance liquid chromatography （UPLC）method was adopted. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid in 23 batches of M. dodecandrum were determined by quantitative analysis of multi-components by single-marker （QAMS）method，using vitexin as the internal reference. Then 1，1-diphenyl-2-picrylhydrazyl（DPPH）free radical method ，2，2′-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid ） diammonium salt （ABTS）method and ferric ion reduction/antioxidant power （FRAP）method were applied to determine the antioxidant activity of 23 batches of M. dodecandrum . Grey correlation analysis and bivariate correlation analysis were used to evaluate the correlation between six components and antioxidant activity. RESULTS The content of vitexin were 0.021％-0.182％. The contents of gallic acid ，protocatechuic acid ，isovitexin，rutin and ellagic acid by QAMS method were 0.008％-0.042％， 0.003％-0.023％，0.071％-0.283％，0.013％-0.140％ and 0.006％-0.021％，respectively. Compared with the results of external standard method ，P was greater than 0.05. Grey correlation analysis showed that the grey correlation coefficients between the contents of six components an d antioxidant activity was 0.727 6- 0.866 9. Bivariate correlation analysis showed that the contents of vitexin ，isovitexin and rutin were positively correlated with antioxidant activity （P＜0.05 or P＜0.01），the content of gallic acid and protocatechuic acid were negatively correlated with antioxidant activity （P＜0.05）. There was no significant correlation between ellagic acid and antioxidant activity.CONCLUSIONS QAMS method is successfully established for the simultaneous determination of six components in M. dodecandrum. The six components in M. dodecandrum are highly correlated with antioxidant activity.