Objective To observe the levels of von Willebrand factor ( vWF) expressed by human umbilical vein endothelial cells ( HUVECs) infected by aspergillus fumigatus ( AF) alone or treatment with cytochalasin D, N-cadherin monoclonal antibody, dexamethasone, respectively, so as to explore the mechanism of angioinvasion in invasive aspergillosis. Methods An in vitro model of HUVECs infected by AF hypha was established. The experiment included six groups, ie. a sham control group, a TNF-αgroup, an AF hypha group, a cytochalasin D group, a N-cadherin antibody group, and a dexamethasone group. Cell supernatants were collected to detect the levels of vWF at 2 h, 6 h, 12 h, and 18 h by enzyme linked immunosorbent assay ( ELISA) . Results Compared with that of vWF at 2 h, the level was higher at 18 h in the sham controlgroup and the TNF-αgroup, and higher at 6 h, 12 h, and 18 h in the other groups( P lt; 0. 05) . Compared with the sham control group, the level of vWF in each experiment group increased at 2 h, 6 h, 12 h, and 18 h except that in the N-cadherin antibody group at 2 h ( P lt; 0. 05) . The level of vWF in TNF-α group was higher than that in the AF hypha group at 2 h, but lower at 18 h. ( P lt; 0. 05) . The level of vWF was not significantly different between the cytochalasin D group and the AF hypha group at each time point. The level of vWF was lower in the N-cadherin antibody group than that in the AF hypha group at 2 h and 6 h ( P lt;0. 05) . The level of vWF was not significantly different between the dexamethasone group and the AF hypha group at each time point. Conclusion HUVECs infected by AF hypha overexpress vWF. N-cadherinmonoclonal antibody can reduce the expression of vWF, but cytochalasin D or dexamethasone has no significant effect on it.
Objective To study the advantages of heat and moisture exchangers compared with heated humidifiers in reducing the incidence of ventilator-associated pneumonia ( VAP) . Methods We searched PubMed as well as reference lists from publications to collect randomized controlled trials which comparing heat and moisture exchangers with heated humidifiers in preventing VAP for mechanically ventilated patients. Meta-analysis was performed using software Review Manager 5. 0. Results Fifteen randomized controlled trials were included. There was no difference in incidence of VAP among the patients managed with moisture exchangers or heated humidifiers ( OR1. 18, 95% CI [ 0. 96, 1. 44] ) . The subgroup of patients using moisture exchangers had lower VAP incidence compared with those using heated humidifiers without heated wire circuits ( OR 1. 39, 95% CI [ 1. 08, 1. 79] ) . There were no differences between the compared groups in mortality, length of intensive care unit stay, or duration of mechanical ventilation. Conclusion The available evidence indicates that moisture exchangers are superior to heated humidifiers without heated wire circuits, and not to heated humidifiers with heated wire circuits to prevent VAP.