Efficacy of amiodarone and lidocaine for preventing ventricular fibrillation after aortic cross-clamp release in open heart surgery: a meta-analysis of randomized controlled trials.

OBJECTIVE: The relative preventative efficacy of amiodarone and lidocaine for ventricular fibrillation (VF) after release of an aortic cross-clamp (ACC) during open heart surgery has not been determined. This meta-analysis was designed to systematically evaluate the influence of amiodarone, lidocaine, or placebo on the incidence of VF after ACC. METHODS: Prospective randomized controlled trials (RCTs) that compared the VF-preventative effects of amiodarone with lidocaine, or amiodarone or lidocaine with placebo were included. PubMed, EMBASE, and the Cochrane Library were searched for relevant RCTs. Fixed or randomized effect models were applied according to the heterogeneity of the data from the selected studies. RESULTS: We included eight RCTs in the analysis. Pooled results suggested that the preventative effects of amiodarone and lidocaine were comparable (relative risk (RR)=1.12, 95% confidence interval (CI): 0.70 to 1.80, P=0.63), but both were superior to the placebo (amiodarone, RR=0.71, 95% CI: 0.51 to 1.00, P=0.05; lidocaine, RR=0.63, 95% CI: 0.46 to 0.88, P=0.006). The percentage of patients requiring electric defibrillation counter shocks (DCSs) did not differ significantly among patients administered amiodarone (RR=0.21, 95% CI: 0.04 to 1.19, P=0.08), lidocaine (RR=2.44, 95% CI: 0.13 to 44.02, P=0.55), or the placebo (RR=0.56, 95% CI: 0.25 to 1.25, P=0.16). CONCLUSIONS: Amiodarone and lidocaine are comparably effective in preventing VF after ACC, but the percentage of patients who subsequently require DCSs does not differ among those administered amiodarone, lidocaine, or placebo.

[Extraction of agglutinin from Oncomelania hupensis and its haemagglutination activity].

OBJECTIVE: To explore the extraction methods of agglutinin from Oncomelania hupensis snail and study its haemagglutination activity. METHODS: Protein obtained by ammonium sulfate fractionation precipitation with 20%-100% saturation of ammonium sulfate. Its haemagglutination activity was determined by rabbit erythrocytes. The precipitation which could agglutinate rabbit erythrocytes was diluted with 2.5 mg/ml D-galactose, D-fructose, D-glucose, saccharose, maltose and lactose, respectively, and then their haemagglutination activity was tested. Snail agglutinin were incubated at different temperatures (25-90 degrees C) and assayed for agglutinating activity. The effect of pH on the haemagglutination activity was determined by using the PBS buffer at different pH values (3.0-10.0). RESULTS: Oncomelania snail agglutinin exhibited high haemagglutination activity in 20%-40% saturated ammonium sulfate pellet. Lactose and galactose could inhibit the haemagglutination activity of snail agglutinin. The agglutinin showed maximum activity at pH 7.0. In temperature range of 30-70 degrees C, the haemagglutination activity decreased with increasing temperature, and all activity lost beyond 80 degrees C. CONCLUSION: Galactose/lactose specific agglutinin exists in Oncomelania snail, its haemagglutination activity is affected by pH and temperature.

[Isolation and purification of Oncomelania hupensis agglutinin and determination of its molecular weight].

OBJECTIVE: To isolate and purify agglutinin from Oncomelania hupensis snail and determine its molecular weight. METHODS: Agglutinin was preliminarily isolated from snail tissue homogenate by 0%-40% saturated ammonium sulfate, and then successively purified with Sephadex G-75 gel filtration and Sepharose 4B affinity chromatography. Bradford assay was used to determine the protein content. The agglutination activity was determined by rabbit erythrocytes. The purity of agglutinin preparations was assessed by SDS-PAGE. The molecular weight of agglutinin subunit was determined by Sephadex G-75 gel filtration. RESULTS: The specific activity of snail tissue homogenate was 21.74 titer/mg. After ammonium sulfate precipitation, Sephadex G-75 gel filtration and Sepharose 4B affinity chromatography, the specific activity of snail agglutinin from the homogenate solution increased to 61.93 titer/mg, 75.89 titer/mg and 963.86 titer/mg, respectively. SDS-PAGE analysis indicated that snail agglutinin (M, 53,000) was purified by Sephadex G-75 gel filtration and Sepharose 4B chromatography. The molecular weight of the snail agglutinin produced by Sephadex G-75 gel filtration was Mr 78,000. CONCLUSION: Combined use of salt fractionation, gel filtration and affinity chromatography can be efficient for extraction and purification of agglutinin from Oncomelania hupensis species. The snail agglutinin is characterized as mono subunit protein with a molecular weight of Mr 78,000.