Abstract Background: Bungarus multicinctus is one of the most dangerous venomous snakes prone to cardiopulmonary damage with extremely high mortality. In our previous work, we found that glutamine (Gln) and glutamine synthetase (GS) in pig serum were significantly reduced after Bungarus multicinctus bite. In the present study, to explore whether there is a link between the pathogenesis of cardiopulmonary injury and Gln metabolic changes induced by Bungarus multicinctus venom. We investigated the effect of Gln supplementation on the lung and heart function after snakebite. Methods: We supplemented different concentrations of Gln to mice that were envenomated by Bungarus multicinctus to observe the biological behavior, survival rate, hematological and pathological changes. Gln was supplemented immediately or one hour after the venom injection, and then changes in Gln metabolism were analyzed. Subsequently, to further explore the protective mechanism of glutamine on tissue damage, we measured the expression of heat-shock protein70 (HSP70), NF-κB P65, P53/PUMA by western blotting and real-time polymerase in the lung and heart. Results: Gln supplementation delayed the envenoming symptoms, reduced mortality, and alleviated the histopathological changes in the heart and lung of mice bitten by Bungarus multicinctus. Additionally, Gln increased the activity of glutamine synthetase (GS), glutamate dehydrogenase (GDH) and glutaminase (GLS) in serum. It also balanced the transporter SLC7A11 expression in heart and lung tissues. Bungarus multicinctus venom induced the NF-κB nuclear translocation in the lung, while the HO-1 expression was suppressed. At the same time, venom activated the P53/PUMA signaling pathway and the BAX expression in the heart. Gln treatment reversed the above phenomenon and increased HSP70 expression. Conclusion: Gln alleviated the glutamine metabolism disorder and cardiopulmonary damage caused by Bungarus multicinctus venom. It may protect lungs and heart against venom by promoting the expression of HSP70, inhibiting the activation of NF-κB and P53/PUMA, thereby delaying the process of snake venom and reducing mortality. The present results indicate that Gln could be a potential treatment for Bungarus multicinctus bite.

Abstract Objective This study aimed to identify the predictors and threshold of failure in neonatal acute respiratory distress syndrome. Methods Newborns with severe acute respiratory distress syndrome aged 0-28 days and gestational age ≥36 weeks were included in the study if their cases were managed with non-extra corporal membrane oxygenation treatments. Patients were divided into two groups according to whether they died before discharge. Predictors of non-extra corporal membrane oxygenation treatment failure were sought, and the threshold of predictors was calculated. Results A total of 103 patients were included in the study. A total of 77 (74.8%) survived hospitalization and were discharged, whereas 26 (25.2%) died. Receiver operating characteristic analysis of oxygen index, pH, base excess, and combinations of these indicators demonstrated the advantage of the combination of oxygen index and base excess over the others variables regarding their predictive ability. The area under the curve for the combination of oxygen index and base excess was 0.865. When the cut-off values of oxygen index and base excess were 30.0 and −7.4, respectively, the sensitivity and specificity for predicting death were 77.0% and 84.0%, respectively. The model with base excess added a net reclassification improvement of 0.090 to the model without base excess. Conclusion The combination of oxygen index and base excess can be used as a predictor of outcomes in neonates receiving non-extra corporal membrane oxygenation treatment for acute respiratory distress syndrome. In neonates with acute respiratory distress syndrome, if oxygen index >30 and base excess <−7.4, non-extra corporal membrane oxygenation therapy is likely to lead to death.

ABSTRACT Objective: To evaluate the influence of sub-minimum inhibitory concentrations (MICs) of ciprofloxacin (CIP) on biofilm formation and virulence factors of Escherichia coli clinical isolates. Methods: Sub-MICs of CIP were determined using growth curve experiments. The biofilm-forming capacity of E. coli clinical isolates and E. coli ATCC 25922 treated or untreated with sub-MICs of CIP was assessed using a crystal violet staining assay. The biofilm structure of E. coli isolate was assessed with scanning electron microscopy (SEM). The expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were measured using quantification RT-PCR (qRT-PCR) in E. coli isolates and E. coli ATCC 25922. Results: Based on our results, the sub-MICs of CIP were 1/4 MICs. Sub-MICs of CIP significantly inhibited biofilm formation of E. coli clinical isolates and E. coli ATCC 25922 (p < 0.01). SEM analyses indicated that the biofilm structure of the E. coli changed significantly after treatment with sub-MICs of CIP. Expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were also suppressed. Conclusions: The results revealed that treatment with sub-MICs of CIP for 24 h inhibited biofilm formation and reduced the expression of virulence genes and biofilm formation genes in E. coli.