MicroRNA is a class of short-chain non-coding RNA that regulates gene expression at post-transcriptional level.It can participate in the pathophysiology processes of tumor regulation,neurodegenerative disease,and cardiovascular disease.Recent studies have shown that microRNA can play a reguhtory role in ischemic brain damage through autophagy.This article reviews the effect of microRNA on autophagy after cerebral ischamia and its possible mechanisms.

【Objective】 To explore the relationship between preoperative anemia and perioperative red blood cell (RBC) transfusion and postoperative outcomes in patients undergoing mitral valve surgery. 【Methods】 The clinical data, laboratory findings, blood transfused and outcomes data of 493 patients who underwent mitral valve surgery in Fuwai Hospital in 2017 were collected by blood transfusion management system and retrospectively analyzed by SPSS. The patients were divided into anemia group (n=34, male Hb<120 g/L and female Hb<110 g/L) and non-anemia group (n=459) .The measurement data were statistically analyzed with t test or rank sum test, and enumeration data by Fisher test and Chi-square test, and then all analyzed by binary logistics regression. 【Results】 The incidence of anemia before mitral valve surgery was 6.90% (34/493). Perioperative erythrocyte dosage (U) (median), erythrocyte transfusion rate, ICU stay time (d) (median) and hospital mortality rate(%) in anemia group and non-anemia group were 4.00 vs 0.00 (OR: 2.55, 95% CI: 1.70~3.40, P<0.05), 67.65% vs 21.35% (OR: 12.98, 95% Cl: 5.21~31.15, P<0.05), 2.50 vs 2.00 (B: 0.71, 95% Cl: 0.08~1.33, P<0.05) and 5.88 vs 0.22(P<0.05)respectively. 【Conclusion】 Preoperative anemic is independently associated with perioperative RBC transfusion in patients undergoing mitral valve surgery, and may increase ICU length of stay and hospital mortality.