Aim To evaluate the protective effects of salvianolic acid B on the ISO-induced myocardial is-chemic injury model of rats and the influence of regula-ting NLRP3 associated protein on myocardial ischemia. Method All rats were randomly divided into control group, model group and Sal B 5, 10, 15 mg · kg-1 groups. For 7 days, rats in Sal B groups were given by introperitoneal injection of 5, 10, 15 mg·kg-1 Sal B, rats in control group and model group were given the same volume of normal saline. Rats were subcutane-ously multi-point injected ISO ( 30 mg · kg-1 ) for 2 days on the fifth administrating day. The myocardial protective effect of Sal B was evaluated from electrocar-diogram( ECG), myocardial tissue pathological chan-ges, serum myocardial enzymes, oxidation index and inflammatory cytokine, myocardial tissue of NLRP3 related protein expression. Results Sal B could re-duce the degree of myocardial tissue necrosis and the infiltration of inflammatory cells, reduce T-wave values of ECG(P<0. 05 or P<0. 01). Compared with model group, CK values, GOT values and IL-1β values of rats in different dose groups were significantly lower, and MDA values and LDH values of rats in middle-and high-dose groups were significantly lower ( P<0. 05 or P<0. 01 ) . However, T-SOD values of rats middle-and high-dose groups were significantly higher ( P <0. 05 or P<0. 01). Meanwhile,the NLRP3, Caspase-1 and IL-1β protein level in myocardial tissue of the rats in different dose groups compared with model group had reduced ( P <0. 05 or P <0. 01 ) . Conclu-sion Sal B has protective effects on myocardial ische-mic rats, its mechanism may be related with inhibition of decreasing the expression of NLRP3 inflammasome associated protein, which can suppress the generation of inflammatory cytokines.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.