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Features of the airway microbiome in persons with cystic fibrosis (pwCF) are correlated with disease progression. Microbes have traditionally been classified for their ability to tolerate oxygen. It is unknown whether supplemental oxygen, a common medical intervention, affects the airway microbiome of pwCF. We hypothesized that hyperoxia significantly impacts the pulmonary microbiome in cystic fibrosis. In this study, we cultured spontaneously expectorated sputum from pwCF in artificial sputum medium under 21%, 50%, and 100% oxygen conditions using a previously validated model system that recapitulates microbial community composition in uncultured sputum. Culture aliquots taken at 24, 48, and 72 h, along with uncultured sputum, underwent shotgun metagenomic sequencing with absolute abundance values obtained with the use of spike-in bacteria. Raw sequencing files were processed using the bioBakery pipeline to determine changes in taxonomy, predicted function, antimicrobial resistance genes, and mobile genetic elements. Hyperoxia reduced absolute microbial load, species richness, and diversity. Hyperoxia reduced absolute abundance of specific microbes, including facultative anaerobes such as Rothia and some Streptococcus species, with minimal impact on canonical CF pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus. The effect size of hyperoxia on predicted functional pathways was stronger than that on taxonomy. Large changes in microbial cooccurrence networks were noted. Hyperoxia exposure perturbs airway microbial communities in a manner well tolerated by key pathogens. Supplemental oxygen use may enable the growth of lung pathogens and should be further studied in the clinical setting. IMPORTANCE The airway microbiome in persons with cystic fibrosis (pwCF) is correlated with lung function and disease severity. Supplemental oxygen use is common in more advanced CF, yet its role in perturbing airway microbial communities is unknown. By culturing sputum samples from pwCF under normal and elevated oxygen conditions, we found that increased oxygen led to reduced total numbers and diversity of microbes, with relative sparing of common CF pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus. Supplemental oxygen use may enable the growth of lung pathogens and should be further studied in the clinical setting.

Objective: This study aimed to formulate a numerical approach (finite element modelling (FEM)) to calculate pressure values generated by compression garments on a compressible limb analogue, and to validate the numerical approach using experimental measurements. Existing models were also compared. Method: Experimentally measured pressure values and deformation caused by compression bands on a compressible human limb analogue were compared with values predicted using the Young–Laplace equation, a previously formulated analytical model and the FEM. Results: The FEM provided greater accuracy in predicting the pressure generated by compression bands compared to existing models. The FEM also predicted deformation of the limb analogue with good agreement relative to experimental values. Conclusion: It was concluded that modelling the non-uniform manner in which the way a limb analogue is compressed should be incorporated into future modelling of the pressures generated by compression garments on a compressible limb analogue. Declaration of interest: The authors have no conflicts of interest to declare. [ABSTRACT FROM AUTHOR]

This letter discusses the impact of tobacco smoking on bronchiectasis, a condition characterized by the widening of the airways in the lungs. The study found that approximately half of patients with bronchiectasis have a history of tobacco smoking, but the development of bronchiectasis is not solely dependent on smoking. The study also found that there were no significant differences in symptoms, treatments, or lung function between smokers and non-smokers with bronchiectasis. However, the presence of chronic obstructive pulmonary disease (COPD) had a more negative impact on outcomes than smoking history alone. The study also revealed an overdiagnosis of COPD, delaying the diagnosis of bronchiectasis. The study suggests the need for accurate phenotyping of patients with bronchiectasis and further research into the underlying mechanisms. [Extracted from the article]

A tetra L-prolinylmethyl derivative of a tetra-sulfonated calix[4]resorcarenes is an effective chiral NMR solvating agent for water-soluble compounds with phenyl, pyridyl, bicyclic aromatic, or indole rings. The effectiveness of a calix[4]resorcarenes prepared from N-methyl-L-alanine as a chiral NMR discriminating agent is compared to the L-prolinylmethyl derivative. for other types of water-soluble organic salts is described.