Safety of incremental inhaled lipopolysaccharide challenge in humans

Abnormalities of Coagulation and Fibrinolysis Assessed by Thromboelastometry in an Endotoxic Shock Model in Piglets Treated with Nitric Oxide and Hydrocortisone

This is an animal model study to investigate changes in hemostasis during endotoxemic shock and to determine whether the combination of inhaled nitric oxide (iNO) + intravenous hydrocortisone had an effect on clot formation and fibrinolysis. iNO selectively decreases pulmonary artery pressure, without affecting cardiac index or systemic vascular resistance; however, the results of studies on the possible consequences of iNO administration on coagulation are inconsistent and require further research. Thirty-four piglets were included. Administering endotoxin caused severe hypodynamic shock. Half of the animals received iNO (30 ppm) + hydrocortisone, starting 3 h after endotoxin infusion and continuing to the end of the study. All animals developed coagulation disorders, manifested by a tendency to hypocoagulation; at the same time, fibrinolysis was impaired. Coagulation and fibrinolysis disorders persisted after endotoxin infusion was discontinued, with worse severity in the animals that died before the study was terminated. Administering iNO + hydrocortisone did not cause further changes in coagulation and fibrinolysis parameters, either during or after the endotoxin challenge, suggesting that potential therapeutic interventions with iNO to lower pulmonary arterial pressure will not affect hemostasis.

Smoking related environmental microbes affecting the pulmonary microbiome in Chinese population

BACKGROUND

Smoking is a serious public health problem that affects human health conditions. Although there is evidence that microorganisms are associated with smoking-related lung diseases, the relationship between the rich lung microbiome of upper respiratory tract groups and smoking has not been studied.

OBJECTIVE

In this study, we investigated the effects of smoking on environmental microbes and lung microbiome in the Chinese population and provided clues for the role of smoking in the development of respiratory disease.

METHODS

Bronchoalveolar lavage fluid samples were collected from 55 individuals with a history of smoking. Microbial gene sequencing was carried out through NGS technology. We analyzed and compared the diversity, community structure, and species abundance of bronchoalveolar lavage microbiome between smokers and nonsmokers, to speculate the effects of smoking on the lung microbiome.

RESULTS

Smoking hardly affected the α diversity of microbial groups of bronchoalveolar lavage, but it had a huge influence on the microbiome composition. The relative abundance of Rothia, Actinomycetes, Haemophilus, Porphyrins, Neisseria, Acinetobacter, and Streptococcus genera had a remarkable increase in the smoking group. On the other hand, the relative abundance of Plusella and Veronella decreased significantly.

CONCLUSION

Smoking may change the environmental microbes and then alter the structure of the lung microbiome, which may lead to smoking-related diseases.

Methods used in clinical development of novel anti-asthma therapies

In recent years, it has become increasingly important to get as much as possible information on clinical efficacy already in the early phases of drug development. For proof of concept (POC) studies testing novel anti-inflammatory drugs in asthma, there are several validated exacerbation models, inducing various aspects of the airway inflammation and airway responsiveness. The choice of the appropriate asthma model depends on the drug's targets within the inflammatory process. For adequate assessment of the drug's anti-inflammatory potential, it is crucial to choose adequate (surrogate) biomarkers. Ideally, these should include measures of airway response, central and peripheral airway inflammation and airway hyperresponsiveness. Overall, there are validated non-invasive sampling techniques for the measurement of inflammatory markers in asthma that can be applied as outcome parameters in early clinical trials. If adequately implemented, these measurements can provide early indication of proof of pharmacological and potential therapeutic efficacy-even in first administration to humans.

LPS inhalation challenge: a new tool to characterize the inflammatory response in humans

Inhaling bacterial endotoxin and its derivative LPS can induce a distinct inflammatory response, varying among hosts. Experimental LPS-inhalation is an established procedure in inflammation research. We evaluated experimental LPS-inhalation in 20 young healthy volunteers to determine the safety and the reproducibility of markers of inflammation and clinical findings (symptoms, lung function, exhalative NO, and body temperature). LPS was increased every 30 min up to cumulative 100 microg, the protocol was repeated after 2, 4, and 6 weeks. During 71 provocations, 13 episodes of clinical complaints were observed in 10 subjects. Those were a total of 11 local reactions (15.5%, e.g., cough), and six systemic reactions (8.5%, e.g., fatigue). All adverse events resolved spontaneously within 10 h. Changes of FEV(1) and eNO showed no significant differences between the four visits. In the majority of our subjects (88.2% on visit 1-3, 76.5% on visit 4), a rise in body temperature (>0.5 degrees C) was recorded and normalised latest after 24 h. On the first and the last visit, serum concentrations of CrP and LBP increased significantly and correlated well with each other (r=0.71; P<0.001). LPS-challenge is a safe and tolerable tool to investigate inflammatory response in humans and could lead to better characterization of patients with chronic inflammatory disease.