Objective To observe the changes of nitric oxide (NO) levels in plasma during cardiopul-monary resuscitation (CPR) and to compare the effects of aminoguanidine (AG) and NG-nitro-L-arginine methyl ester (L-NAME) on CPR. Method This was a prospective, randomized animal study performed at the Function Laboratory of Lanzhou University. Cardiac arrest was electrically induced and was left untreated for 5 min. After performing chest compression for 1 min, 40 domestic rabbits were divided into four groups (n = 10) to receive ei-ther 20 mg/kg AG, 25 mg/kg L-NAME, 0.02 mg/kg epinephrine or 2 ml saline placebo before defibrillation. Successfully resuscitated rabbits were observed for a further 4 h. Hernodynamics variables and cardiac functions were monitored with appropriate instrumentation. Arterial blood NO levels were examined at baseline, at the end of 1 min chest compression and at 15, 30, 60 and 120 min after survival. Repeated measures analysis of variance was used to determine statistical significance between groups. Results During chest compression, the mean + stan-dard deviation coronary perfusion pressure was higher in the AG group (40±10 mmHg) than in the L-NAME group (34±8 mmHg; P =0.001) and was higher in both groups with the control group (20±5 mmHg; both P =0.000). Left ventricular + dp/dtmax and- dp/dtmax were higher in the AG group than in the L-NAME group. In the surviving rabbits, the left ventricular + dp/dtmax and - dp/dtmax were higher in the AG and L-NAME groups than in the epinephrine and control groups and were higher in the AG group (4783±912, 4409±827 mmHg/s)than in the b-NAME group (3554±847, 3398±764 mmHg/s; P = 0.001 and 0.023, respectively). Conclu-sions Both AG and L-NAME increased the coronary perfusion pressure, and improved left ventricular systolic and diastolic function during CPR and prevented post-resuscitation myocardial dysfunction. However, AG was signifi-canfly superior to L-NAME.

Objective: To explore the protective effect and mechanism of Rhodiola rosea(Rho) bionic nanomedicine in rats with acute pancreatitis. Methods: Erythrocyte membrane vesicles(EMV) were used as biomimetic nanomedicine coating materials to construct Rho biomimetic nanomedicine. Meanwhile, rat models of acute pancreatitis were constructed and divided into acute pancreatitis model(AP) group, Rho group, EMV group and Rhodiola rosea erythrocyte membrane vesicles(R-EMV) group. R-EMV group rats were further treated with NLRP3 activator BMS-986299(R-EMV+BMS-986299 group) and inhibitor MCC950(R-EMV+MCC950 group). The changes of abdominal water volume were observed, and serum levels of interleukin(IL-6), IL-1β, endothelin(ET), diamine oxidase(DAO), malondialdehyde(MDA), superoxide dismutase(SOD) and glutathione(GSH) were detected by enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe the pathological changes of pancreatic tissue. Immunohistochemistry, reverse transcription-polymerase chain reaction(RT-PCR) and Western blot were used to analyze the expression of NOD-like receptor protein 3(NLRP3) and nuclear transcription factor-Kappa B(NF-κB) in pancreatic tissue. Results: The prepared R-EMVs were nearly circular, the average particle size was(244.61±1.08) nm, and the Zeta potential was-(11.13±1.25) mV. At the same time, the EMV could load(58.67±0.79) μg of Rho. Compared with Sham group, the abdominal water volume of rats in AP group was significantly higher(t=33.79,P<0.01), and the levels of peripheral blood immune indexes IL-1β, IL-6, ET and DAO increased(t=38.25, 42.54, 29.20, 34.92, allP<0.01). In AP group, there were obvious tissue hyperemia and edema, widening of lobular space, infiltration of a large number of inflammatory cells, and increased pancreatic pathological score(t=30.06,P<0.01). Compared with AP group, abdominal water volume, dry-wet weight ratio of pancreas, pathological score, amylase and lipase levels in Rho group decreased(F=1 523.7, 543.3, 839.9, 446.1, 172.2,P<0.05). Compared with other groups, the levels of serum IL-1β, IL-6, ET and DAO in AP group decreased to some extent. Compared with AP group, NF-κB p65 and NLRP3 protein levels and NF-κB and NLRP3 immunohistochemical staining scores decreased in R-EMV group(t=24.54 and 26.91, bothP<0.001). At the same time, the levels of serum IL-1β, IL-6, ET, DAO, MDA, SOD and GSH in R-EMV+MCC950 group were significantly lower than those in AP group, R-EMV group and R-EMV+BMS-986299 group. Conclusion R-EMV has a good pancreatic protection effect in acute pancreatitis, which is related to reducing the activity of NF-κB/NLRP3 pathway and down-regulating the expression of inflammatory factors such as IL-6 and oxidative stress indicators such as MDA.

Objective:To provide a promising and optimal laboratory susceptibility-testing method for the clinical usage of antibiotic (polymyxin), four susceptibility-testing methods were performed and the broth microdilution (BMD) was chosen as the gold standard.Methods:A total number of eighty-eight nonduplicate clinical Enterobacteriaceae specimes were collected from January to December of 2019 in the First Affiliated Hospital, Fujian Medical University. Among the clinical specimens, of which six strains were positive for mcr-1. The minimal inhibitory concentration (MIC) of polymyxin of the clinical specimens were examined by the following methods: (1) broth microdilution, (2) colistin broth disk elution, (3) Vitek-2?, (4)BD PhoenixTM,(5)commercial broth microdilution. With BMD as reference, essential agreement (EA), categorical agreement(CA), very major error(VME) and major error (ME) of polymyxins for different methods were analyzed. The Kappa-consistency testing, paired Chi-square testing and the Spearman-rank correlation testing were used to analyze the consistency between the four antimicrobial susceptibility testing methods and the gold standard.Results:Taking broth microdilution as reference, the EA of colistin broth disk elution, Vitek-2?, BD PhoenixTM, commercial broth microdilution were 94.32% (83/88), 92.05% (81/88), 90.90% (80/88), and 96.59%(85/88), respectively. The CA of all the four methods were 100% (88/88). No VME and ME were recorded for four methods. Moreover, the consistency between four susceptibility testing methods and the gold standard is acceptable (Kappa values=1, P<0.001, McNemar test P=1 and r>0.5, P<0.05). Conclusions:In the present work, four susceptibility testing methods all met the standards recommended jointly by the Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing, of which the performance of the commercial broth microdilution and CBDE fared relatively well. Thus, these four methods could be routinely used in clinical microbiology laboratory of our hospital for colistin and polymyxin B susceptibility testing.