AIM:To study the electrophysiological effects of resveratrol from grape and polygonum cuspidate on autorhythmicity organization in left ventricular outflow tract of guinea pig and its intracellular mechanism.METHODS:In choosing guinea pig weighing 250~300 g,the action potential,including its MDP(maximal diastolic potential),APA(amplitude of AP),Vmax(maximal rate of zero phase depolarization),VDD[velocity of diastolic(phase 4)depolarization],RPF(rate of pacemaker firing)and APD_ 50,APD_ 90(the duration of 50% and 90% repolarization of action potential),were observed and recorded by means of the intracellular microelectrode technique.RESULTS:(1)Resveratrol could reduce the electric activity of left ventricular outflow tract.Resveratrol(30、60、120 ?mol/L)not only significantly decreased APA and Vmax,but also decreased VDD and RPF respectivily(P

Effect of strophanthidin (Str) on intracellular calcium concentration ([Ca2+]i) was investigated on isolated ventricular myocytes of guinea pig. Single ventricular myocytes were obtained by enzymatic dissociation technique. Fluorescent signal of [Ca2+]i was detected with confocal microscopy after incubation of cardiomycytes in Tyrode's solution with Fluo3-AM. The result showed that Str increased [Ca2+]i in a concentration-dependent manner. The ventricular myocytes began to round-up into a contracture state once the peak level of [Ca2+]i was achieved in the presence of Str (10 μmol·L-1), but remained no change in the presence of Str (1 and 100 nmol·L-1). Tetrodotoxin (TTX), nisodipine, and high concentration of extracellular Ca2+ changed the response of cardiomycytes to Str (1 and 100 nmol·L-1), but had no obvious effects on the action of Str (10 μmol·L-1). The elevation of [Ca2+]i caused by Str at all of the detected concentrations was partially antagonized by rynodine (10 μmol·L-1) or the removal of Ca2+ from Tyrode's solution. In Na+, K+-free Tyrode's solution, the response of cardiomycytes in [Ca2+]i elevation to Str (10 μmol·L-1) was attenuated, while remained no change to Str (1 and 100 nmol·L-1). TTX, nisodipine, and high concentration of extracellular Ca2+ changed the response of cardiomycytes to Str at all of the detected concentrations in Na+, K+-free Tyrode's solution. The study suggests that the elevation of [Ca2+]i by Str at the low (nomomolar) concentrations is partially mediated by the extracellular calcium influx through Ca2+ channel or a "slip mode conductance" of TTX sensitive Na+ channel. While the effect of Str at high (micromolar) concentrations was mainly due to the inhibition of Na+, K+-ATPase. Directly triggering the release of intracellular Ca2+ from sarcoplasmic reticulum (SR) by Str may be also involved in the mechanism of [Ca2+]i elevation.

Objective: This study was summarized and analyzed the reporting data of pressure ulcer events in children for nearly 4 years. We expected this study can provide a recommendation for design of the subsequent reporting system, especially the pressure ulcer. Methods: A total of 207 children with pressure ulcers from January 2015 to September 2018 were exported from the adverse event reporting system that made a retrospective analysis based on structured method. Results: Among the 207 pressure ulcer cases, 173 (83.57%) cases were hospital acquired, 65 (31.40%) were female, 104 (50.24%) were male, and 38 (18.36%) were missing data. The factors that are prone to pressure ulcers in children are in CICU(74/173), the occipital (83/207), and with stage I(112/207). 111(64.16%)cases were delayed reporting, and the median delayed reporting time was 38(143) days. There are many missing records in the description of the event, the medical treatment, the analysis of the possible causes and other items. In univariate analysis, the setting was associated with missing records in system; the occipital and stage I pressure ulcers were associated with a delayed reporting of hospital acquired pressure ulcers. Conclusions For the prevention of pressure ulcers in children, different high-risk populations should have corresponding strategies. The adverse event of pressure ulcers were reported to be missed and delayed that was attributed to the cumbersome process. The reporting process and system should be standardized.