Acute lung injury (ALI) is a severe form of lung inflammation causing acute respiratory distress syndrome in patients. ALI pathogenesis is closely linked to uncontrolled alveolar inflammation.We hypothesize that specific enzymes of the glycolytic pathway could function as key regulators of alveolar inflammation. Therefore, we screened isolated alveolar epithelia from mice exposed to ALI induced by injurious ventilation to assess their metabolic responses. These studies pointed us towards a selective role for isoform 3 of the 6-phosphofructo-2-kinase/fructose-2,6bisphosphatase (PFKFB3). Pharmacologic inhibition or genetic deletion of Pfkfb3 in alveolar epithelia (Pfkfb3 loxp/loxp SPC-ER-Cre+ mice) was associated with profound increases in ALI during injurious mechanical ventilation or acid installation. Studies in genetic models linked Pfkfb3 expression and function to hypoxia-inducible factor Hif1a. Intra-tracheal pyruvate instillation not only reconstituted Pfkfb3 loxp/loxp or Hif1a loxp/loxp SPC ER Cre+ mice, but pyruvate was also effective in ALI treatment of wild-type mice. Finally, proof-of-principle studies in human lung biopsies confirmed increased PFKFB3 staining in injured lungs and co-localized PFKFB3 to alveolar epithelia. These studies reveal a specific role for PFKFB3 in counterbalancing alveolar inflammation and lay the groundwork for novel metabolic therapeutic approaches during ALI.

In-flight medical emergencies (IMEs) are acute onboard events of illnesses or injuries with potential immediate risk to a passenger's short- or long-term health, or life. IMEs are significant events that are related to public safety concerns. With the increasing amount of annual air travel every year, it is expected that the number of encountered IMEs will continue to grow. Thus, it will be critical to develop and implement appropriate measures to manage IMEs with the best possible outcome. Despite the fact that most IMEs are self-limited with no serious adverse events, serious IME can lead to death, disability, or other unfavorable health outcomes, particularly as a result of suboptimal medical care. In this article, we systematically reviewed the published up-to-date evidence on the subject of in-flight emergencies with a specific focus on pediatric population.

Acute respiratory distress syndrome (ARDS) remains a significant cause of morbidity and mortality in critically ill patients. Oxidative stress and inflammation play crucial role in pathogenesis of ARDS. Extracellular superoxide dismutase (EC-SOD) is abundant in the lung and is important enzymatic defense against superoxide. Human single nucleotide polymorphism in matrix binding region of EC-SOD leads to substitution of arginine to glycine at position 213 (R213G) and results in release of EC-SOD into alveolar fluid, without affecting enzyme activity. We hypothesized that R213G EC-SOD variant protects against lung injury and inflammation via blockade of neutrophil-recruitment in infectious model of methicillin-resistant S. aureus (MRSA) pneumonia. After inoculation with MRSA, WT mice had impaired integrity of alveolar-capillary barrier and increased levels of IL-1β, IL-6, and TNF-α in the broncho-alveolar lavage fluid (BALF), while infected mice expressing R213G EC-SOD variant maintained the integrity of alveolar-capillary interface and had attenuated levels of proinflammatory cytokines. MRSA-infected mice expressing R213G EC-SOD variant also had attenuated neutrophil numbers in BALF and decreased expression of neutrophil chemoattractant CXCL1 by the alveolar epithelial ATII cells, compared to the infected WT group. The decreased neutrophil numbers in R213G mice were not due to increased rate of apoptosis. Mice expressing R213G variant had differential effect on neutrophil functionality, - the generation of neutrophil extracellular traps (NETs) but not myeloperoxidase (MPO) levels were attenuated in comparison to WT controls. Despite having the same bacterial load in the lung as WT controls, mice expressing R213G EC-SOD variant were protected from extrapulmonary dissemination of bacteria.

Acute respiratory distress syndrome is a heterogeneous pathophysiological process responsible for significant morbidity and mortality in pediatric intensive care patients. Diagnosis is defined by clinical characteristics that identify the syndrome after development. Subphenotyping patients at risk of progression to ARDS could provide the opportunity for therapeutic intervention. microRNAs, non-coding RNAs stable in circulation, are a promising biomarker candidate. We conducted a single-center prospective cohort study to evaluate random forest classification of microarray-quantified circulating microRNAs in critically ill pediatric patients. We additionally selected a sub-cohort for parallel metabolomics profiling as a pilot study for concurrent use of miRNAs and metabolites as circulating biomarkers. In 35 patients (n = 21 acute respiratory distress, n = 14 control) 15 microRNAs were differentially expressed. Unsupervised random forest classification accurately grouped ARDS and control patients with an area under the curve of 0.762, which was improved to 0.839 when subset to only patients with bacterial infection. Nine metabolites were differentially abundant between acute respiratory distress and control patients (n = 4, both groups) and abundance was highly correlated with miRNA expression. Random forest classification of microRNAs differentiated critically ill pediatric patients who developed acute respiratory distress relative to those who do not. The differential expression of microRNAs and metabolites provides a strong foundation for further work to validate their use as a prognostic biomarker.

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