Hypothermic machine perfusion with metformin-University of Wisconsin solution for ex vivo preservation of standard and marginal liver grafts in a rat model

AIM To compare the effect of University of Wisconsin(UW) solution with or without metformin, an AMP-activated protein kinase(AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex vivo by hypothermic machine perfusion(HMP).METHODS Eighteen young(4 mo old) and 18 aged(17 mo old)healthy male SD rats were selected and randomly divided into three groups: control group, UW solution perfusion group(UWP), and UW solution with metformin perfusion group(MUWP). Aspartate aminotransferase(AST), alanine aminotransferase(ALT), lactate dehydrogenase(LDH), interleukin-18(IL-18), and tumor necrosis factor-alpha(TNF-α) in the perfused liquid were tested. The expression levels of AMPK and endothelial nitric oxide synthase(e NOS) in liver sinusoidal endothelial cells were also examined.Additionally, microscopic evaluation of the harvested perfused liver tissue samples was done. RESULTS AST, ALT, LDH, IL-18 and TNF-α levels in the young and aged liver-perfused liquid were, respectively,significantly lower in the MUWP group than in the UWP group(P < 0.05), but no significant differences were found between the young and aged MUWP groups.Metformin increased the expression of AMPK and e NOS protein levels, and promoted the extracellular release of nitric oxide through activation of the AMPK-e NOS mediated pathway. Histological examination revealed that in the MUWP group, the extent of liver cells and tissue damage was significantly reduced compared with the UWP group.CONCLUSION The addition of metformin to the UW preservative solution for ex vivo HMP can reduce rat liver injury during cold ischemia, with significant protective effects on livers, especially of aged rats.

Analysis of risk factors for early stent thrombosis in the Chinese population:A multicenter restrospective study

BACKGROUND:The predictive scoring systems for early stent thrombosis(EST)remains blank in China.The study aims to evaluate the risk factors and conduct a prediction model of EST in the Chinese population.METHODS:EST was defined as thrombosis that occurs within the first 30 days after primary percutaneous coronary intervention(PCI).Patients from ten Chinese hospitals diagnosed as stent thrombosis(ST)from January 2010 to December 2016 were retrospectively included as the study group.A control group(1 case:2 controls)was created by including patients without ST,major adverse cardiovascular events,or cerebrovascular events during follow-up.The present study evaluated 426 patients with single-vessel lesions and ultimately included 40 patients with EST and 80 control patients,who were included to identify factors that predicted EST and to develop a prediction scoring system.The other 171 patients without integrated 1:2 pair were used for external validation.RESULTS:EST was independently associated with a low hemoglobin concentration(adjusted odds ratio[OR]0.946,95%confi dence interval[95%CI]0.901-0.993,P=0.026),a high pre-PCI Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score(OR 1.166,95%CI 1.049-1.297,P=0.004),and a DAPT(DAPT)duration of<30 days(OR 28.033,95%CI 5.302-272.834,P<0.001).The simple EST prediction score provided an area under the curve(AUC)of 0.854(95%CI 0.777-0.932,P<0.001)with 70.0%sensitivity and 90.0%specifi city,and 0.742(95%CI 0.649-0.835,P<0.001)with 54.5%sensitivity and 81.0%specifi city for external validation dataset.CONCLUSIONS:EST may be independently associated with DAPT discontinuation within 30 days,a low hemoglobin concentration,and a high SYNTAX score.The scoring system also has a good ability to predict the risk of EST and may be useful in the clinical setting.