BackgroundMesenchymal stem cells microvesicles (MSC-MVs) stabilize endothelial barrier function in acute lung injury (ALI); however, the detailed mechanism remains to be further defined. Hepatocyte growth factor (HGF), which is derived from MSC-MVs, might have a key role in the restoration of endothelial barrier function by MSC-MVs.MethodsMSCs with lentiviral vector-mediated HGF gene knockdown (siHGF-MSC) were generated. A co-culture model of pulmonary microvascular endothelial cells and MSC-MVs collected from MSCs or siHGF-MSCs after 24 h of hypoxic culture was utilized. Then, endothelial paracellular and transcellular permeabilities were detected. VE-cadherin, and occludin protein expression in the endothelial cells was measured using Western blot. Endothelial cell proliferation was analysed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. Endothelial cell apoptosis was analysed using TUNEL assay. Finally, IL-6 and IL-10 production was determined via an enzyme-linked immunosorbent assay (ELISA).ResultsTreatment with MSC-MVs significantly decreased LPS-induced endothelial paracellular and transcellular permeabilities, and the effect was significantly inhibited after HGF gene knockdown in MSC-MVs. Furthermore, treatment with MSC-MVs increased the expression of the endothelial intercellular junction proteins VE-cadherin and occludin. Treatment with MSC-MVs also decreased endothelial apoptosis and induced endothelial cell proliferation. Finally, the treatment reduced IL-6 production and increased IL-10 production in the conditioned media of endothelial cells. However, the effects of the treatment with MSC-MVs were inhibited after HGF gene knockdown.ConclusionsMSC-MVs protect the barrier functions of pulmonary microvascular endothelial cells, which can be partly attributed to the presence of HGF in the MSC-MVs.

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Background: The efficacy of low-dose hydrocortisone therapy in the management of septic shock remains controversial in critical care for many years. Hence, we performed this meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA) to evaluate its effect on clinical outcome among adult patients with septic shock. Methods: We identified relevant RCTs published from inception to March 7, 2018 comparing low-dose hydrocortisone with placebo or no intervention in adults admitted to the intensive care unit (ICU) for septic shock. Meta-analyses were performed for the primary and secondary outcomes. The risk of bias was assessed using the Cochrane Collaboration’s instrument. Trial sequential analysis was used to pool the results from the included studies for the primary outcomes. Results: Thirteen studies were retrieved by our literature search strategy. There were no significant differences in 28-day mortality (odds ratio [OR] = 0.90, 95% confidence interval [CI] = 0.81-1.00; P = .05) and hospital mortality (OR = 0.91, 95% CI = 0.82-1.02; P = .09) between the 2 groups, which were confirmed by TSA. However, there was a significant improvement in shock reversal in the hydrocortisone group (OR = 1.33, 95% CI = 1.02-1.72; P = .03). Furthermore, subgroup analyses revealed that hydrocortisone plus fludrocortisone statistically reduced the rate of 28-day mortality (OR = 0.79, 95% CI = 0.64-0.97; P = .03), ICU mortality (OR = 0.77, 95% CI = 0.63-0.95; P = .02), and hospital mortality (OR = 0.77, 95% CI = 0.63-0.95; P = .01) in comparison with the placebo, the results were also confirmed by TSA. Conclusion: Among adult patients with septic shock, the use of low-dose hydrocortisone compared with control did not confer overall survival benefits, albeit improving shock reversal rate. The benefit of reducing 28-day mortality, ICU mortality, and hospital mortality was observed in combination use of hydrocortisone and fludrocortisone.

BackgroundSmall trials suggest that levosimendan is associated with a favorable outcome in patients undergoing cardiac surgery. However, recently published larger-scale trials did not provide evidence for a similar benefit from levosimendan. We performed a meta-analysis to assess the survival benefits of levosimendan in patients undergoing cardiac surgery and to investigate its effects in subgroups of patients with preoperative low-ejection fraction (EF).MethodsWe identified randomized clinical trials through 20 April 2017 that investigated levosimendan therapy versus control in patients undergoing cardiac surgery. Individual patient data from each study were compiled. Meta-analyses were performed for primary outcomes, secondary outcomes and serious adverse events, and subgroup analyses according to the preoperative EF of enrolled patients were also conducted. The risk of bias was assessed using the Cochrane risk-of-bias tool.ResultsSeventeen studies involving a total of 2756 patients were included. Levosimendan therapy was associated with a significant reduction in 30-day mortality (RR 0.67; 95% CI, 0.49 to 0.93; p = 0.02) and reduced the risk of death in single-center trials (RR 0.49; 95% CI, 0.30 to 0.79; p = 0.004) and in subgroup trials of inferior quality (RR 0.39; 95% CI, 0.17 to 0.92; p = 0.02); however, in multicenter and in high-quality subgroup-analysis trials, no significant difference in mortality was observed between patients who received levosimendan therapy and controls (p > 0.05). However, in high-quality subgroup trials, levosimendan therapy was associated with reduced mortality in patients in a preoperative low-EF subgroup (RR 0.58; 95% CI, 0.38 to 0.88; p = 0.01). Similarly, only patients in the preoperative low-EF subgroup benefited in terms of reduced risk of renal replacement therapy (RR 0.54; 95% CI, 0.34 to 0.85; p = 0.007). Furthermore, levosimendan therapy was associated with a significant reduction in intensive care unit (ICU) length of stay (MDR −17.19; 95% CI, −34.43 to −2.94; p = 0.02).ConclusionsIn patients undergoing cardiac surgery, the benefit of levosimendan in terms of survival was not shown in multicenter or in high-quality trials; however, levosimendan therapy was associated with reduced mortality in patients with preoperative ventricular systolic dysfunction.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-017-1848-1) contains supplementary material, which is available to authorized users.

PurposeRestrictive red blood cell transfusion strategies remain controversial in patients undergoing cardiac surgery. We performed a meta-analysis to assess the prognostic benefits of restrictive red blood cell transfusion strategies in patients undergoing cardiac surgery.MethodsWe identified randomized clinical trials through the 9th of December 2017 that investigated a restrictive red blood cell transfusion strategy versus a liberal transfusion strategy in patients undergoing cardiac surgery. Individual patient data from each study were collected. Meta-analyses were performed for the primary and secondary outcomes. The risk of bias was assessed using the Cochrane Risk of Bias Tool. A trial sequential analysis (TSA)-adjusted random-effects model was used to pool the results from the included studies for the primary outcomes.ResultsSeven trials involving a total of 8886 patients were included. The TSA evaluations suggested that this meta-analysis could draw firm negative results, and the data were sufficient. There was no evidence that the risk of 30-day mortality differed between the patients assigned to a restrictive blood cell transfusion strategy and a liberal transfusion strategy (odds ratio (OR) 0.98; 95% confidence interval (CI) 0.77 to 1.24; p = 0.87). Furthermore, the study suggested that the restrictive transfusion strategy was not associated with significant increases in pulmonary morbidity (OR 1.09; 95% CI 0.88 to 1.34; p = 0.44), postoperative infection (OR 1.11; 95% CI 0.95 to 1.3; p = 0.58), acute kidney injury (OR 1.03; 95% CI 0.92 to 1.14; p = 0.71), acute myocardial infarction (OR 1.01; 95% CI 0.80 to 1.27; p = 0.78), or cerebrovascular accidents (OR 0.97; 95% CI 0.72 to 1.30; p = 0.66).ConclusionsOur meta-analysis demonstrates that the restrictive red blood cell transfusion strategy was not inferior to the liberal strategy with respect to 30-day mortality, pulmonary morbidity, postoperative infection, cerebrovascular accidents, acute kidney injury, or acute myocardial infarction, and fewer red blood cells were transfused.Electronic supplementary materialThe online version of this article (10.1186/s13054-018-2062-5) contains supplementary material, which is available to authorized users.