Colonic Oxygen Microbubbles Augment Systemic Oxygenation and CO2 Removal in a Porcine Smoke Inhalation Model of Severe Hypoxia

Inhalation injury can lead to pulmonary complications resulting in the development of respiratory distress and severe hypoxia. Respiratory distress is one of the major causes of death in critically ill patients with a reported mortality rate of up to 45%. The present study focuses on the effect of oxygen microbubble (OMB) infusion via the colon in a porcine model of smoke inhalation-induced lung injury. Juvenile female Duroc pigs (n=6 colonic OMB, n=6 no treatment) ranging from 39-51 kg in weight were exposed to smoke under general anesthesia for 2 h. Animals developed severe hypoxia 48 h after smoke inhalation as reflected by reduction in SpO2 to 66.3 % +/- 13.1% and PaO2 to 45.3 +/- 7.6 mmHg, as well as bilateral diffuse infiltrates demonstrated on chest x-ray. Colonic OMB infusion (75 - 100 mL/kg dose) resulted in significant improvements in systemic oxygenation as demonstrated by an increase in PaO2 of 13.2 +/- 4.7 mmHg and SpO2 of 15.2% +/- 10.0% out to 2.5 h, compared to no-treatment control animals that experienced a decline in PaO2 of 8.2 +/- 7.9 mmHg and SpO2 of 12.9% +/- 18.7% over the same timeframe. Likewise, colonic OMB decreased PaCO2 and PmvCO2 by 19.7 +/- 7.6 mmHg and 7.6 +/- 6.7 mmHg, respectively, compared to controls that experienced increases in PaCO2 and PmvCO2 of 17.9 +/- 11.7 mmHg and 18.3 +/- 11.2 mmHg. We conclude that colonic OMB therapy has potential to treat patients experiencing severe hypoxemic respiratory failure.

Impact of forest fire smoke on the state of the central nervous system of rats

Introduction. The adverse negative effect of forest fire smoke on human health represents a unique interdisciplinary challenge to the scientific community. The influence of forest fire smoke on locomotor activity, cognitive indices, and brain bioelectrical activity parameters in exposed rats is presented. Materials and methods. Experimental studies were carried out on outbred white male rats. The animals of the experimental group were exposed to smoke inhalation forest fire for one day. Immediately after the end of the exposure, the animals were examined, including testing in an open field and Morris water maze, as well as an electroencephalographic examination. Results. At twenty-four-hour exposure to wildfire smoke in the model, conditions showed increasing motor and research activity of male rats against the backdrop of growing anxiety. Disorders of indicators of spatial memory and navigation learning were not revealed. On the encephalogram of the exposed animals, in comparison with the control group, the δ-rhythm range predominated, more pronounced in the leads of the right hemisphere. A decrease in the power spectrum and the average amplitude β1-rhythm, as well as a tendency to decrease the average amplitude of θ-rhythm, were revealed. The indices of the primary EEG rhythms did not have statistically significant differences when compared with the control group. Conclusion. The results showed that forest fire smoke leads to changes in the bioelectric activity of brain structures and dysregulation of individual behaviour in animals, all of which may indicate the formation of increased levels of stressing beyond physiological adaptation.

Air pollution, human health and climate change: Newspaper coverage of Australian bushfires

We examine 512 Australian newspaper articles published over a 5-year period (2016 to 2021) that report on air pollution due to bushfire smoke and resulting human health impacts. We analyze to what extent these articles provide information on the possible range of negative health impacts due to bushfire smoke pollution, and to what extent they report on climate change as a driver behind increased bushfire risk. A temporary surge in articles in our sample occurs during the unusually severe 2019/2020 Black Summer bushfires. However, most articles are limited to general statements about the health impacts of bushfire smoke, with only 50 articles in the sample (9%) mentioning an explicit link between bushfire smoke inhalation and cardiovascular and respiratory problems or increases in mortality risk. 148 of the 512 articles in the sample (29%) established a connection between bushfire risk and climate change. We carry out a further keyword analysis to identify differences in reporting by Australia’s two main publishing groups (News Corp Australia and Nine Entertainment), which shows that articles in News Corp Australia outlets offered the lowest climate change coverage. We suggest that more detailed communication strategies are needed to strengthen public preparedness for future impacts.

Determination of Benzoic Acid and Benzyl Alcohol in E-Liquids (JUULTM Pods) by Isotopic Dilution High-Performance Liquid Chromatography and Tandem Mass Spectrometry

Summary The new pod devices like JUULTM, Vuse AltoTM, mybluTM, and other “pod-mod” related products had a huge impact on the e-cigarette market, especially among teens and young adults due in particular to aggressive marketing on social media, wide availability, and discrete use due to their special design. These pod devices are designed to deliver nicotine levels per puff comparable to combustible cigarettes while producing smaller amounts of visible exhaled aerosol from the heating of e-liquids. Some of these liquids contain high concentrations of acids, such as benzoic acid, to allow higher nicotine deliveries with less harshness and throat irritation. Benzoic acid is a potential source of the human carcinogen benzene and a chemical of concern. Besides acids, flavoring agents such as benzyl alcohol, a local anesthetic that could facilitate tobacco smoke inhalation are also common in these devices. Both benzoic acid and benzyl alcohol in e-liquids might be of relevance for the health risk of vapers. An isotope dilution high-performance liquid chromatography-tandem mass spectrometry (ID-HPLC-MS/MS) method has been developed for the detection of benzoic acid and benzyl alcohol in the JUULTM brand e-liquids. The sample preparation consisted of a simple dilution followed by a mechanical stirring process. ID-HPLC-MS/MS was used to separate, identify, and quantify the benzoic acid and/or benzyl alcohol in diluted extracts. Detection limits were 0.11 and 9.05 ng/μL for benzyl alcohol and benzoic acid, respectively. Product variability estimated from the analysis of seven different e-liquids in triplicates (n = 21) yielded relative standard deviations ranging from 4.3% to 16.0% for benzyl alcohol and 6.3% to 11.1% for benzoic acid. The amount of benzoic acid (32.8 ± 2.8 mg/g; 3.3 ± 0.3%, w/w) and the nicotine-benzoic acid molar ratio (1.15 ± 0.02) remained relatively consistent among pod flavors. [Contrib. Tob. Nicotine Res. 30 (2021) 212–220]

Development and Application of Multidimensional Lipid Libraries to Investigate Lipidomic Dysregulation Related to Smoke Inhalation Injury Severity

Lipids play many biological roles including membrane formation, protection, insulation, energy storage, and cell division. These functions have brought great interest to lipidomic studies for understanding their dysregulation in toxic exposure, inflammation, and diseases. However, lipids have shown to be analytically challenging due to their highly isomeric nature and vast concentration ranges in biological matrices. Therefore, powerful multidimensional techniques such as those integrating liquid chromatography, ion mobility spectrometry, collision induced dissociation, and mass spectrometry (LC-IMS-CID-MS) have recently been implemented to separate lipid isomers as well as provide structural information and increased feature identification confidence. These multidimensional datasets are however extremely large and highly complex, resulting in challenges in data processing and annotation. Here, we have overcome these challenges by developing sample-specific multidimensional libraries using the freely available software Skyline. Specifically, the human plasma library developed for this work contains over 500 unique, experimentally validated lipids, which is combined with adapted Skyline functions for highly confident lipid annotations such as indexed retention time (iRT) for retention time prediction and IMS drift time filtering for increased sensitivity and selectivity. For broad comparison with other lipidomic studies, this human plasma database was initially used to annotate LC-IMS-CID-MS data from a NIST SRM 1950 extract, giving comparable results to previous studies. This workflow was then utilized to assess matched plasma and bronchoalveolar lavage fluid (BALF) samples from patients with varying degrees of smoke inhalation injury to identify potential lipid-based patient prognostic and diagnostic markers.