Cardiopulmonary prognosis of prophylactic endotracheal intubation in patients with upper gastrointestinal bleeding undergoing endoscopy

BACKGROUND:It is controversial whether prophylactic endotracheal intubation(PEI)protects the airway before endoscopy in critically ill patients with upper gastrointestinal bleeding(UGIB).The study aimed to explore the predictive value of PEI for cardiopulmonary outcomes and identify high-risk patients with UGIB undergoing endoscopy.METHODS:Patients undergoing endoscopy for UGIB were retrospectively enrolled in the eICU Collaborative Research Database(eICU-CRD).The composite cardiopulmonary outcomes included aspiration,pneumonia,pulmonary edema,shock or hypotension,cardiac arrest,myocardial infarction,and arrhythmia.The incidence of cardiopulmonary outcomes within 48 h after endoscopy was compared between the PEI and non-PEI groups.Logistic regression analyses and propensity score matching analyses were performed to estimate effects of PEI on cardiopulmonary outcomes.Moreover,restricted cubic spline plots were used to assess for any threshold effects in the association between baseline variables and risk of cardiopulmonary outcomes(yes/no)in the PEI group.RESULTS:A total of 946 patients were divided into the PEI group(108/946,11.4%)and the non-PEI group(838/946,88.6%).After propensity score matching,the PEI group(n=50)had a higher incidence of cardiopulmonary outcomes(58.0%vs.30.3%,P=0.001).PEI was a risk factor for cardiopulmonary outcomes after adjusting for confounders(odds ratio[OR]3.176,95%confidence interval[95%CI]1.567-6.438,P=0.001).The subgroup analysis indicated the similar results.A shock index>0.77 was a predictor for cardiopulmonary outcomes in patients undergoing PEI(P=0.015).The probability of cardiopulmonary outcomes in the PEI group depended on the Charlson Comorbidity Index(OR 1.465,95%CI 1.079-1.989,P=0.014)and shock index>0.77(compared with shock index≤0.77[OR 2.981,95%CI 1.186-7.492,P=0.020,AUC=0.764]).CONCLUSION:PEI may be associated with cardiopulmonary outcomes in elderly and critically ill patients with UGIB undergoing endoscopy.Furthermore,a shock index greater than 0.77 could be used as a predictor of a worse prognosis in patients undergoing PEI.

Optima of Trypsin-Catalyzed Hydrolysis and Its Inhibition Determined by SDS-PAGE

SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conducted using SDS-PAGE. From the quantitative analysis to the electrophoresis bands of BSA and its hydrolysis products in SDS-PAGE pattern, the change of trypsin activity was determined, and then the optimum temperature at 40°C and the optimum pH at pH 8.5 - 8.7 for trypsin activity were obtained. All the target bonds in BSA molecule could be hydrolyzed at the same time by trypsin. The inhibition was due to the binding of inhibitor to trypsin, which made it impossible for trypsin to touch the substrate protein. SDS-PAGE was demonstrated to be also an effect method for assaying the characteristics of trypsin activity and its inhibition.

The relationship of morphology and catalytic performance of CeO_(2) catalysts for reducing nitrobenzene to azoxybenzene under the base-free condition

CeO_(2) morphology was proposed to be a crucial factor for reducing nitrobenzene to azoxybenzene under the base-free condition.Herein,the structure-activity relationship of CeO_(2) catalysts was explored to improve the azoxybenzene yield.A series of CeO_(2) catalysts we re synthesized with seven morphologies to obtain different Ce^(3+) proportion and various surface areas.Notably,the catalytic performance of these samples for reducing nitrobenzene to azoxybenzene enhanced with the increasing Ce^(3+) proportio n.With the highest surface Ce^(3+) proportion,the Rod-CeO_(2) catalyst exhibited 100% conversion of nitrobenzene and 89.8% azoxybenzene selectivity in 7 h at 150℃ under 1 MPa CO.Moreover,the preliminary mechanistic analysis indicated that the inhabitation of azoxybenzene to by-product azobenzene resulted in the high selectivity of azoxybenzene.