Electronic cigarette inhalation alters innate immunity and airway cytokines while increasing the virulence of colonizing bacteria

MMP12 deficiency attenuates menthol e-cigarette plus house dust-mite effects on pulmonary iron homeostasis and oxidative stress

BACKGROUND

Little is known regarding the pulmonary effects induced by the inhalation of menthol-flavored e-cigarette aerosols on asthma exacerbation, despite the popularity of these devices and flavors among youth and young adults. In the lungs, matrix metalloproteinase 12 (MMP12) expressed and secreted by both alveolar macrophages and bronchial epithelial cells plays an essential role in airway remodeling, a key feature of severe asthma. In this study, we investigated the role of MMP12 in menthol-flavored e-cigarette aerosol exposures plus house-dust mite (HDM)-induced asthmatic responses.

METHODS

We exposed wild-type (WT) and MMP12 knockout (KO) juvenile female mice to well-characterized menthol-flavored e-cigarette aerosols followed by either PBS or HDM treatment, and evaluated pulmonary outcomes in terms of iron metabolism, oxidative stress responses and pulmonary inflammation.

RESULTS

We found high levels of iron in the menthol-flavored e-cigarette aerosol. This correlated with e-cigarette + HDM WT mice exhibiting disruption of pulmonary iron metabolism, suggesting a defense mechanism against iron-mediated toxicity. This was evidenced by altered lung protein concentrations of ferroportin, ferritin, lactoferrin, and transferrin, activation of the antioxidant response element (ARE) pathway and up-regulated expression of NQO1 in e-cigarette + HDM WT mice. Further, despite decreased neutrophilic inflammation, MUC5AC, an oxidative stress inducible mucin, was increased in the e-cigarette + HDM WT mice. In contrast, MMP12 KO mice were protected against iron-induced oxidative stress responses, highlighting a crucial role of MMP12 in this model.

CONCLUSION

These findings revealed in vivo evidence supporting a crucial role for iron metabolism in nicotine salt iron-rich ENDS aerosol toxicity.

Impacts of vaping and marijuana use on airway health as determined by exhaled breath condensate (EBC)

Across the United States, there is increased use of cannabis products and electronic delivery systems for cannabis products and nicotine, yet little is known about their impacts on lung health. We analyzed exhaled breath condensate of 254 participants who were non-users and users who used cannabis and tobacco products. The 132 participants reported using a product ("users") were distributed into cohorts of tobacco products and cannabis products, with some participants following into multiple cohorts. Targeted analysis of inflammatory oxylipins found up-regulation among persons using tobacco products, while cannabis users had concentrations closer to nonusers, and often down-regulated. Untargeted screening of 403 significant metabolites found tobacco users had similar breath profiles, and that cannabis users had a similar profile that was closer to the profile of nonusers. Metabolites were significantly higher in breath of people using combustion products (tobacco and cannabis) relative to nonusers, and significantly lower in e-device users (nicotine and THC). Our work demonstrates the relative impact of e-delivery systems and cannabis products compared to traditional cigarette smoking on lung metabolic profiles.

E-Cigarette effects on oral health: A molecular perspective

Electronic cigarettes (e-cigarettes) have emerged as a potential alternative to traditional smoking and may aid in tobacco harm reduction and smoking cessation. E-cigarette use has notably increased, especially among young non-tobacco users, raising concerns due to the unknown long-term health effects. The oral cavity is the first and one of the most crucial anatomical sites for the deposition of e-cigarette aerosols. E-cigarette aerosols contain nicotine, flavors, volatile organic compounds, heavy metals, carcinogens, and other hazardous substances. These aerosols impact the oral cavity, disrupting host-microbial interactions and triggering gingivitis and systemic diseases. Furthermore, oral inflammation and periodontitis can be caused by proinflammatory cytokines induced by e-cigarette aerosols. The toxic components of e-cigarette aerosols increase the cellular reactive oxygen species (ROS) levels, reduce antioxidant capacity, increase DNA damage, and disrupt repair processes, which may further contribute to harmful effects on oral epithelum, leading to inflammatory and pre-malignant oral epithelial lesions. In this review, we analyze the toxicological properties of compounds in e-cigarette aerosols, exploring their cytotoxic, genotoxic, and inflammatory effects on oral health and delving into the underlying molecular mechanisms. Further research is essential to understand the impact of e-cigarettes on oral health and make informed regulatory decisions based on reliable scientific evidence.

Oxidative stress promotes lipid-laden macrophage formation via CYP1B1

Emerging evidence suggests that lipid-laden macrophages (LLM) participate in lung damage in various clinical conditions. However, the mechanisms involved in LLM formation are not fully understood. In this study, we aimed to investigate the link between reactive oxygen species (ROS) and LLM formation. We found that ROS triggered by cigarette smoke extract (CSE) or H2O2 significantly promoted LLM formation. Given the key role of ROS in LLM formation, we further demonstrated that LLM formation is induced by various ROS-producing stimuli, including bacteria, oxidized low-density lipoprotein (OxLDL), hyperoxia, and E-cigarette vapor extract (EVE). Meanwhile, cytochrome P450 family-1 subfamily B member 1 (CYP1B1) was highly upregulated in lung macrophages from chronic obstructive pulmonary disease (COPD) patients and CSE-treated macrophages. Functionally, CYP1B1 contributes to the CSE-induced lipid accumulation and LLM formation. CYP1B1 expression and LLM formation were effectively suppressed by antioxidant N-acetylcysteine (NAC) and carvedilol. The formation of LLM was also associated with classically activated M1 but not the M2 state. CSE-induced LLM showed time-dependent alterations in inflammatory response and phagocytic ability. In summary, our study highlights the role of oxidative stress in LLM formation. CYP1B1 contributes to ROS-induced LLM formation and may serve as a therapeutic target for reducing LLM-induced lung damage.

The use of the model organism Caenorhabditis elegans in the investigation of the adverse effects of electronic cigarettes

The use of tobacco products is one of the most preventable risk factors for mortality from a variety of diseases, including cardiovascular, infectious, respiratory, and neoplastic conditions. The use of electronic cigarettes (ECIGs), also known as electronic nicotine delivery devices, has increased significantly in recent years. Nicotine, propylene glycol, and / or glycerine, water, alcohol, flavorings, and other substances are among the many chemicals found in ECIGs that are vaporized and inhaled. A review of the existing literature shows that research dedicated to ECIGs is a rapidly developing and growing field of study. The rationale for the use of ECIGs is that they represent a safer alternative to traditional tobacco products. However, vaping safety profiles are still under development, as this is a relatively recent phenomenon. Various model organisms can be employed to examine the cellular processes that may be altered by exposure to the electronic liquids utilized for vaping. For example, the translucent multicellular eukaryote Caenorhabditis elegans is widely used as a model organism to explain a broad range of biological processes, including aging, stress response, development, and many others. Due to its short lifespan and easy use, C. elegans is an ideal model organism for studying chronic exposure to drugs and environmental toxicology. This review presents a summary of the most recent findings on the impact of electronic cigarettes on the physiological health of this nematode. Preliminary observations made in C. elegans can provide insight into the consequences of exposure to fundamental cellular physiology, which can then be used for future research in humans and mammalian models.

Immunological Effects of Electronic Cigarette Use: A Review of Current Evidence

Electronic cigarettes (EC) have emerged as a popular alternative to traditional tobacco products, but their impact on immune function has raised significant health concerns. This review explores the immunological effects of EC exposure, focusing on innate and adaptive immune responses. Electronic cigarette aerosol (ECA) induces widespread inflammation. These changes compromise immune cell function, impairing neutrophil chemotaxis, phagocytosis, and oxidative burst while increasing macrophage and dendritic cell recruitment and activation. ECA also disrupts epithelial barriers, increasing susceptibility to bacterial and viral infections. Studies show enhanced biofilm formation in bacteria such as Staphylococcus aureus and Streptococcus pneumoniae and impaired antiviral responses against pathogens like influenza A and SARS-CoV-2. Additionally, EC exposure modulates adaptive immunity, affecting T and B cell function and increasing systemic inflammatory markers. The long-term consequences of these immunological disruptions include heightened risks for chronic inflammatory diseases, respiratory infections, and potentially autoimmune conditions. The widespread adoption of EC, particularly among younger users, poses a growing public health challenge. As the popularity of vaping continues to rise, these immunological disruptions could result in increased healthcare burdens in the future, with higher rates of infections, chronic inflammatory diseases, and immune system-related disorders among those who begin using e-cigarettes at a young age. Understanding the full scope of EC-related health risks is essential for informing public health policies and protecting future generations from the potential long-term effects of vaping.

Pathophysiological Responses of Oral Keratinocytes After Exposure to Flavored E-Cigarette Liquids

BACKGROUND

Electronic cigarettes (ECIGs) have grown in popularity, particularly among adolescents and young adults. Flavored ECIG-liquids (E-liquids) are aerosolized by these ECIGs and inhaled into the respiratory system. Several studies have shown detrimental effects of E-liquids in airway tissues, revealing that flavoring agents may be the most irritating component. However, research on the effects of E-liquids on biological processes of the oral cavity, which is the first site of aerosol contact, is limited. Hence, this study focuses on the effects of E-liquid flavors on oral epithelial cells using the OKF6/TERT-2 cell line model.

METHODOLOGY

E-liquid was prepared with and without flavors (tobacco, menthol, cinnamon, and strawberry). OKF6/TERT-2 oral epithelial cells, cultured at 37 °C and 5% CO2, were exposed to 1% E-liquid ± flavors for 24 h. Outcomes determined include cell morphology, media pH, wound healing capability, oxidative stress, expression of mucin and tight junction genes, glycoprotein release, and levels of inflammatory cytokines (TNFα, IL-6, and IL-8).

RESULTS

Exposure to 1% flavored E-liquids negatively affect cellular confluency, adherence, and morphology. E-liquids ± flavors, particularly cinnamon, increase oxidative stress and production of IL-8, curtail wound healing recovery, and decrease glycoprotein release. Gene expression of muc5b is downregulated after exposure to E-liquids. In contrast, E-liquids upregulate occludin and claudin-1.

CONCLUSIONS

This study suggests that ECIG use is not without risk. Flavored E-liquids, particularly cinnamon, result in pathophysiological responses of OKF6/TERT-2 cells. The dysregulation of inflammatory responses and cellular biology induced by E-liquids may contribute to various oral pathologies.

E-Cigarette Use, Cigarette Smoking, and Sex Are Associated With Nasal Microbiome Dysbiosis

INTRODUCTION

Previous research suggests that e-cigarettes can alter immune function, including in the nasal mucosa, in unique ways. The respiratory microbiome plays a key role in respiratory host defense, but the effects of e-cigarettes on the respiratory or nasal microbiome, are not well understood.

AIMS AND METHODS

Using 16S rRNA gene sequencing on nasal samples from adult e-cigarette users, smokers, and nonsmokers, we determined that e-cigarette use and cigarette smoking are associated with differential respiratory microbiome dysbiosis and substantial sex-dependent differences in the nasal microbiome, particularly in e-cigarette users.

RESULTS

Staphylococcus aureus, a common respiratory pathogen, was more abundant in both e-cigarette users and smokers in comparison with nonsmokers, while Lactobacillus iners, often considered a protective species, was more abundant in smokers but less abundant in e-cigarette users in comparison with nonsmokers. In addition, we identified significant dysbiosis of the nasal microbiome between e-cigarette users and smokers with high versus low serum cotinine levels, an indicator of tobacco product use and toxicant exposure. We also analyzed nasal lavage fluid for immune mediators associated with host × microbiota interactions.

CONCLUSIONS

Our analysis identified disruption of immune mediators in the nose of e-cigarette users and smokers, which is indicative of disrupted respiratory mucosal immune responses. Taken together, our data identified unique, sex-dependent host immune dysfunction associated with e-cigarette use in the nasal mucosa. More broadly, our data highlight the need for continued inclusion and careful consideration of sex as an important variable in the context of toxicant exposures.

IMPLICATIONS

This is the first study investigating the effects of e-cigarette use and sex on the nasal microbiome, which is considered an important gatekeeper for protecting the lower respiratory tract from pathogens. We found significant sex, exposure group, and serum cotinine level-associated differences in the composition of the nasal microbiome, demonstrating the importance of considering sex in future nasal microbiome studies and warranting further investigation of the mechanisms by which e-cigarette use dysregulates nasal immune homeostasis.

Environmental Risk Factors for Acute Respiratory Distress Syndrome

Several environmental exposures increase susceptibility to the acute respiratory distress syndrome (ARDS). Specifically, chronic exposure to ambient air pollution, cigarette smoke, and alcohol "prime" the lung via epithelial injury, endothelial dysfunction, and immunomodulatory mechanisms, increasing the risk and severity of ARDS following an array of acute insults. Future research of these pathways may reveal therapeutic targets. Relevant emerging threats, such as electronic cigarettes and vaping, wildfire smoke, and the environmental hazards associated with climate change, may also be associated with ARDS. Building upon existing public policy interventions can prevent substantial morbidity and mortality from ARDS.

Bioactives of the essential oil from the leaves of Eugenia pyriformis Cambess (Myrtaceae) on the effects of tobacco

Introduction

Lung cancer is the most commonly diagnosed and the main cause of cancer death, usually related to cigarette smoking. Furthermore, the microbiota of people exposed to cigarette smoke can be modified, making it difficult to eliminate opportunistic microorganisms. The leaves of Eugenia pyriformis are a by-product of fruit production and, to date, there have been no studies addressing the antiproliferative, anti-inflammatory, and antimicrobial activities.

Objective

Investigate the antimicrobial, Nitric Oxide (NO)-production inhibition, and antiproliferative activities of the essential oil from E. pyriformis leaves and its possible effect on the treatment and prevention of damage caused by tobacco.

Methods

The essential oil (EO) was obtained by hydrodistillation (3 h). Its chemical composition was investigated by GC-MS. It was proposed to investigate antiproliferative activity against human tumor cell lines, namely, breast adenocarcinoma (MCF-7), lung (NCI-H460), cervical (HeLa), and hepatocellular (HepG2) carcinomas. A non-tumor primary culture from pig liver (PLP2) was also tested. The EO capacity to inhibit nitric oxide (NO) production was evaluated by a lipopolysaccharide stimulated murine macrophage cell line. Antibacterial and antifungal activities against opportunistic pathogens were investigated against seven strains of bacteria and eight fungi.

Results

The results indicated the presence of 23 compounds in the essential oil, the majority were spathulenol (45.63%) and β-caryophyllene oxide (12.72%). Leaf EO provided 50% inhibition of nitric oxide production at a concentration of 92.04 µg mL-1. The EO also demonstrated antiproliferative activity against all human tumor cell lines studied, with GI50 values comprised between 270.86 and 337.25 µg mL-1. The essential oil showed antimicrobial potential against the bacteria Listeria monocytogenes (Murray et al.) Pirie (NCTC 7973) and Salmonella Typhimurium ATCC 13311 (MIC 1870 µg mL-1) and fungi Aspergillus versicolor ATCC 11730, Aspergillus ochraceus ATCC 12066, Penicillium ochrochloron ATCC 90288, Penicillium verrucosum var. cyclopium (Westling) Samson, Stolk & Hadlok (food isolate) (MIC 1870 µg mL-1) and Trichoderma viride Pers. IAM 5061 (1,400 µg mL-1).

Conclusion

The demonstrated anti-inflammatory, antiproliferative, and antimicrobial activities in the leaves of E. pyriformis can add value to the production chain of this plant, being a possible option for preventing and combating cancer, including lung cancer.

The paradox of the safer cigarette: understanding the pulmonary effects of electronic cigarettes

Electronic cigarette (e-cigarette) use continues to rise globally. E-cigarettes have been presented as safer alternatives to combustion cigarettes that can mitigate the harm associated with tobacco products; however, the degree to which e-cigarette use itself can lead to morbidity and mortality is not fully defined. Herein we describe how e-cigarettes function; discuss the current knowledge of the effects of e-cigarette aerosol on lung cell cytotoxicity, inflammation, antipathogen immune response, mucociliary clearance, oxidative stress, DNA damage, carcinogenesis, matrix remodelling and airway hyperresponsiveness; and summarise the impact on lung diseases, including COPD, respiratory infection, lung cancer and asthma. We highlight how the inclusion of nicotine or flavouring compounds in e-liquids can impact lung toxicity. Finally, we consider the paradox of the safer cigarette: the toxicities of e-cigarettes that can mitigate their potential to serve as a harm reduction tool in the fight against traditional cigarettes, and we summarise the research needed in this underinvestigated area.

Dual Exposure to E-Cigarette Vapour and Cigarette Smoke Results in Poorer Airway Cell, Monocyte, and Macrophage Function Than Single Exposure

E-cigarette users predominantly also continue to smoke cigarettes. These Dual Users either consume e-cigarettes in locations where smoking is not allowed, but vaping is, or to reduce their consumption of cigarettes, believing it will lead to harm reduction. Whilst it is known that e-cigarette vapour is chemically less complex than cigarette smoke, it has a distinct chemical profile, and very little is known about the health impacts of exposure to both chemical profiles vs. either alone. We simultaneously exposed cells in vitro to non-toxic levels of e-cigarette vapour extract (EVE) and cigarette smoke extract (CSE) to determine their effects on 16HBE14o- airway epithelial cell metabolism and inflammatory response, as well as immune cell (THP-1 cells and monocyte-derived macrophages (MDM) from healthy volunteers) migration, phagocytosis, and inflammatory response. We observed increased toxicity, reduced metabolism (a marker of proliferation) in airway epithelial cells, and reduced monocyte migration, macrophage phagocytosis, and altered chemokine production after exposure to either CSE or EVE. These cellular responses were greater after dual exposure to CSE and EVE. The airway epithelial cells from smokers showed reduced metabolism after EVE (the Switcher model) and dual CSE and EVE exposure. When EVE and CSE were allowed to interact, the chemicals were found to be altered, and new chemicals were also found compared to the CSE and EVE profiles. Dual exposure to e-cigarette vapour and cigarette smoke led to worse functional outcomes in cells compared to either single exposure alone, adding to limited data that dual use may be more dangerous than smoking only.

Unveiling the Impact of Smokers' Self-Construals on the Effectiveness of Smoking Cessation Campaigns: A Comparative Analysis of E-Cigarettes and Combustible Cigarettes

Objective

This research conducted two studies in South Korea to explore the relationship between smokers' self-construals and the types of cigarettes they use, emphasizing their combined effects on cessation campaign effectiveness.

Methods

Study 1 explored how smokers' self-construals influenced their intentions to quit smoking or vaping, considering their primary cigarette usage. Study 2 further investigated this relationship within cessation campaigns, employing messages framed by both self-construal (independent vs. interdependent) and cigarette type (combustible vs. electronic).

Results

The results of Study 1 showed that individuals with a strong interdependent self-construal were more likely to express intentions to quit smoking or vaping when using e-cigarettes compared to combustible cigarettes. Similarly, Study 2 demonstrated that cessation messages for e-cigarettes were more effective in eliciting intentions to quit when presented with an interdependent self-construal frame, while messages for combustible cigarettes showed greater effectiveness with an independent self-construal frame.

Conclusion

Campaigns solely focused on independent self-construals might not effectively persuade e-cigarette users to quit, as they may prioritize communal wellbeing over individual benefits. Adapting anti-e-cigarette campaigns to align with the values of interdependent self-construals could yield better outcomes in promoting cessation among e-cigarette users.

E-cigarette use, psychological distress, and daily activity participation among adults in Riyadh

Objectives

The prevalence of e-cigarettes is significantly increasing among adults as an alternative method to tobacco smoking. However, the chemical products of e-cigarettes have an influence on human general health. Therefore, this study aims to investigate the association between e-cigarette use and psychological distress as well as participation in daily activities among adults in Riyadh, Saudi Arabia. It also evaluates the demographic profile and usage patterns of e-cigarette users.

Methods

This cross-sectional study involved 396 e-cigarette smokers in Riyadh city. An online survey was administered, including questions about smoking patterns and the perceived effects of e-cigarettes on activities of daily living. Additionally, mental health were assessed using the Kessler 6 scale.

Results

Most of the participants were educated young males (61.4%). About 29.5% of the participants reported using e-cigarettes primarily to quit tobacco cigarettes. In addition, e-cigarette usage was significantly associated with lower participation in activities of daily living and higher psychological distress.

Conclusion

This study found that many e-cigarette users are well-educated young individuals who use e-cigarettes as a substitute for traditional cigarettes. However, the study also revealed that using e-cigarettes is associated with negative effects on smokers' daily activities and mental health.

The potential health effects associated with electronic-cigarette

A good old gateway theory that electronic-cigarettes (e-cigarettes) are widely recognized as safer tobacco substitutes. In actuality, demographics also show that vaping cannibalizes smoking, the best explanation of the data is the "common liability". However, the utilization of e-cigarette products remains a controversial topic at present. Currently, there has been a widespread and substantial growth in e-cigarette use worldwide owing to their endless new flavors and customizable characteristics. Furthermore, e-cigarette has grown widespread among smokers as well as non-smokers, including adolescents and young adults. And some studies have shown that e-cigarette users are at greater risk to start using combustible cigarettes while e-cigarettes use was also observed the potential benefits to people who want to quit smoking or not. Although it is true that e-cigarettes generally contain fewer toxic substances than combustible cigarettes, this does not mean that the chemical composition in e-cigarettes aerosols poses absolutely no risks. While concerns about toxic substances in e-cigarettes and their widespread use in the population are reasonable, it is also crucial to consider that e-cigarettes have been associated with the potential for promoting smoking cessation and the clinically relevant improvements in users with smoking-related pathologies. Meanwhile, there is still short of understanding of the health impacts associated with e-cigarette use. Therefore, in this review, we discussed the health impacts of e-cigarette exposure on oral, nasal, pulmonary, cardiovascular systems and brain. We aspire for this review to change people's previous perceptions of e-cigarettes and provide them with a more balanced perspective. Additionally, we suggest appropriate adjustments on regulation and policy for e-cigarette to gain greater public health benefits.

Vaping-Dependent Pulmonary Inflammation Is Ca2+ Mediated and Potentially Sex Specific

Here we use the SCIREQ InExpose system to simulate a biologically relevant vaping model in mice to investigate the role of calcium signaling in vape-dependent pulmonary disease as well as to investigate if there is a gender-based difference of disease. Male and female mice were vaped with JUUL Menthol (3% nicotine) using the SCIREQ InExpose system for 2 weeks. Additionally, 2-APB, a known calcium signaling inhibitor, was administered as a prophylactic for lung disease and damage caused by vaping. After 2 weeks, mice were exposed to lipopolysaccharide (LPS) to mimic a bacterial infection. Post-infection (24 h), mice were sacrificed, and bronchoalveolar lavage fluid (BALF) and lungs were taken. Vaping primed the lungs for worsened disease burden after microbial challenge (LPS) for both males and females, though females presented increased neutrophilia and inflammatory cytokines post-vape compared to males, which was assessed by flow cytometry, and cytokine and histopathological analysis. This increased inflammatory burden was controlled by calcium signaling inhibition, suggesting that calcium dysregulation may play a role in lung injury caused by vaping in a gender-dependent manner.

Rapidly progressive empyema in the setting of vaping in an otherwise healthy patient

Vaping is defined as inhaling and exhaling vapour that is a product of heating a liquid or wax-like material. Electronic cigarettes (e-cigarettes) have become a popular method of smoking in the last decade and are advertised as an alternative to conventional smoking. Since the increase in e-cigarette use, various lung injury patterns have started to appear among users. Recent studies have shown an increased susceptibility to respiratory tract infections among e-cigarette/vaping product users. We present a case of pneumonia caused by Pseudomonas fluorescens complicated by rapidly developing empyema in an otherwise healthy patient.

E-cigarette exposure causes early pro-atherogenic changes in an inducible murine model of atherosclerosis

Introduction: Evidence suggests that e-cigarette use (vaping) increases cardiovascular disease risk, but decades are needed before people who vape would develop pathology. Thus, murine models of atherosclerosis can be utilized as tools to understand disease susceptibility, risk and pathogenesis. Moreover, there is a poor understanding of how risk factors for atherosclerosis (i.e., hyperlipidemia, high-fat diet) intersect with vaping to promote disease risk. Herein, we evaluated whether there was early evidence of atherosclerosis in an inducible hyperlipidemic mouse exposed to aerosol from commercial pod-style devices and e-liquid. Methods: Mice were injected with adeno-associated virus containing the human protein convertase subtilisin/kexin type 9 (PCSK9) variant to promote hyperlipidemia. These mice were fed a high-fat diet and exposed to room air or aerosol derived from JUUL pods containing polyethylene glycol/vegetable glycerin (PG/VG) or 5% nicotine with mango flavoring for 4 weeks; this timepoint was utilized to assess markers of atherosclerosis that may occur prior to the development of atherosclerotic plaques. Results: These data show that various parameters including weight, circulating lipoprotein/glucose levels, and splenic immune cells were significantly affected by exposure to PG/VG and/or nicotine-containing aerosols. Discussion: Not only can this mouse model be utilized for chronic vaping studies to assess the vascular pathology but these data support that vaping is not risk-free and may increase CVD outcomes later in life.

Increased oxidative stress responses in murine macrophages exposed at the air-liquid interface to third- and fourth-generation electronic nicotine delivery system (ENDS) aerosols

Background

New fourth generation electronic nicotine delivery system (ENDS) devices contain high levels of nicotine salt (up to 60 mg/mL), whose cellular and molecular effects on immune cells are currently unknown. Here, we used a physiologically-relevant in vitro air-liquid interface (ALI) exposure model to assess the toxicity of distinct ENDS, a 3rd-generation electronic-cigarette (e-cig) and two 4th-generation ENDS devices (JUUL and Posh Plus).

Methods

Murine macrophages (RAW 264.7) were exposed at the ALI to either air, Menthol or Crème Brûlée-flavored ENDS aerosols generated from those devices for 1-hour per day for 1 or 3 consecutive days. Cellular and molecular toxicity was evaluated 24 h post-exposure.

Results

1-day of Menthol-flavored JUUL aerosol exposure significantly decreased cell viability and significantly increased lactate dehydrogenase (LDH) levels compared to air controls. Further, JUUL Menthol elicited significantly increased reactive oxygen species (ROS) and nitric oxide (NO) production compared to air controls. Posh Crème Brûlée-flavored aerosols displayed significant cytotoxicity - decreased cell viability and increased LDH levels -after 1- and 3-day exposures, while the Crème Brûlée-flavored aerosol produced by the 3rd-generation e-cig device only displayed significant cytotoxicity after 3 days compared to air controls. Further, both Posh and third-generation e-cig Crème Brûlée flavored-aerosols elicited significantly increased ROS plus high levels of 8-isoprostane after 1 and 3 days compared to air controls, indicating increased oxidative stress. Posh and third-generation e-cig Crème Brûlée flavored-aerosols elicited reduction in NO levels after one day, but elicited increase in NO after 3 days. Genes in common dysregulated by both devices after 1 day included α7nAChR, Cyp1a1, Ahr, Mmp12, and iNos.

Conclusion

Our results suggest that ENDS Menthol and Crème Brûlée-flavored aerosol exposures from both 3rd- and 4th-generation ENDS devices are cytotoxic to macrophages and cause oxidative stress. This can translate into macrophage dysfunction. Although 4th-generation disposable ENDS devices have no adjustable operational settings and are considered low-powered ENDS devices, their aerosols can induce cellular toxicity compared to air-exposed control cells. This study provides scientific evidence for regulation of nicotine salt-based disposable ENDS products.

Sex Differences in E-Cigarette Use and Related Health Effects

BACKGROUND

Electronic cigarettes (e-cigarettes) comprise a variety of products designed to deliver nicotine, flavorings, and other substances. To date, multiple epidemiological and experimental studies have reported a variety of health issues associated with their use, including respiratory toxicity, exacerbation of respiratory conditions, and behavioral and physiological effects. While some of these effects appear to be sex- and/or gender-related, only a portion of the research has been conducted considering these variables. In this review, we sought to summarize the available literature on sex-specific effects and sex and gender differences, including predictors and risk factors, effects on organ systems, and behavioral effects.

METHODS

We searched and selected articles from 2018-2023 that included sex as a variable or reported sex differences on e-cigarette-associated effects.

RESULTS

We found 115 relevant studies published since 2018 that reported sex differences in a variety of outcomes. The main differences reported were related to reasons for initiation, including smoking history, types of devices and flavoring, polysubstance use, physiological responses to nicotine and toxicants in e-liquids, exacerbation of lung disease, and behavioral factors such as anxiety, depression, sexuality, and bullying.

CONCLUSIONS

The available literature supports the notion that both sex and gender influence the susceptibility to the negative effects of e-cigarette use. Future research needs to consider sex and gender variables when addressing e-cigarette toxicity and other health-related consequences.

Association between e-cigarette use and asthma among US adolescents: Youth Risk Behavior Surveillance System 2015-2019

BACKGROUND

Previous studies have suggested that e-cigarette use, which has increased rapidly among US adolescents, may cause respiratory distress. This cross-sectional study aimed to investigate the factors associated with e-cigarette use and the relationship between e-cigarette use and asthma among US adolescents.

METHODS

Data from the Youth Risk Behavior Surveillance System between 2015 and 2019 were analyzed, and multivariable logistic regression was used to identify demographic and behavioral factors associated with e-cigarette use. Stratified analyses were conducted to assess the relationship between e-cigarette use and asthma among adolescents by previous combustible product use.

RESULTS

This study found that Hispanic adolescents had lower odds of e-cigarette use than White adolescents in Texas, with factors such as age, substance use, and depression being associated with use. In the US, male gender, previous combustible and substance use, and depression were associated with higher odds of ever using e-cigarettes, while current use was associated with several factors including age and White race. E-cigarette use was significantly associated with asthma among adolescents who have never used combustible products in both Texas and the entire US after adjusting for covariates (OR 1.32, 95% CI 1.06-1.66 and OR 1.18, 95% CI 1.02-1.37, respectively).

CONCLUSION

The findings from this study can be used to inform public health strategies and policies aimed at reducing e-cigarette use and its associated health risks among adolescents.

Electronic nicotine delivery systems (ENDS): A convenient means of smoking?

Electronic nicotine delivery systems (ENDS), which are becoming increasingly popular in many parts of the world, have recently become more sophisticated in terms of their more active content and better controlled vaporisation. This review begins by describing how cigarette smoking led to the development of ENDS as a means of combatting nicotine addiction. ENDS are usually categorised as belonging to one of only three main generations, but a fourth has been added in order to differentiate the latest, most powerful, most advanced and innovative that have improved heating efficiency. Descriptions of the principal substances contained in ENDS are followed by considerations concerning the risk of toxicity due to the presence of albeit low concentrations of such a variety of compounds inhaled over a long time, and the increasingly widespread use of ENDS as a means of smoking illicit drugs. We also review the most widely used pharmacotherapeutic approaches to smoking cessation, and recent epidemiological data showing that ENDS can help some people to stop smoking. However, in order to ensure their appropriate regulation, there is a need for higher-quality evidence concerning the health effects and safety of ENDS, and their effectiveness in discouraging tobacco smoking.

Not all vaping is the same: differential pulmonary effects of vaping cannabidiol versus nicotine

RATIONALE

Vaping has become a popular method of inhaling various psychoactive substances. While evaluating respiratory effects of vaping have primarily focused on nicotine-containing products, cannabidiol (CBD)-vaping is increasingly becoming popular. It currently remains unknown whether the health effects of vaping nicotine and cannabinoids are similar.

OBJECTIVES

This study compares side by side the pulmonary effects of acute inhalation of vaporised CBD versus nicotine.

METHODS

In vivo inhalation study in mice and in vitro cytotoxicity experiments with human cells were performed to assess the pulmonary damage-inducing effects of CBD or nicotine aerosols emitted from vaping devices.

MEASUREMENTS AND MAIN RESULTS

Pulmonary inflammation in mice was scored by histology, flow cytometry, and quantifying levels of proinflammatory cytokines and chemokines. Lung damage was assessed by histology, measurement of myeloperoxidase activity and neutrophil elastase levels in the bronchoalveolar lavage fluid and lung tissue. Lung epithelial/endothelial integrity was assessed by quantifying BAL protein levels, albumin leak and pulmonary FITC-dextran leak. Oxidative stress was determined by measuring the antioxidant potential in the BAL and lungs. The cytotoxic effects of CBD and nicotine aerosols on human neutrophils and human small airway epithelial cells were evaluated using in vitro air-liquid interface system. Inhalation of CBD aerosol resulted in greater inflammatory changes, more severe lung damage and higher oxidative stress compared with nicotine. CBD aerosol also showed higher toxicity to human cells compared with nicotine.

CONCLUSIONS

Vaping of CBD induces a potent inflammatory response and leads to more pathological changes associated with lung injury than vaping of nicotine.

Concern over tobacco and marijuana perceptions and use among adolescents and young adults with cystic fibrosis

BACKGROUND

This study assesses use and perceptions of short- and long-term harms associated with cigarettes, e-cigarettes, and smoked marijuana among adolescents and young adults (AYAs) with cystic fibrosis (CF).

METHODS

A total of 205 AYAs with CF completed an online survey querying about use, safety perceptions, and education related to traditional cigarettes, electronic cigarettes (e-cigarettes), and smoked marijuana. In addition, parents of AYAs with CF and CF healthcare providers were asked questions about experiences in avoidance education.

RESULTS

AYA participants with CF reported using tobacco and marijuana at rates lower than that of the general AYA population, with heavy use considerably lower in this population. AYAs with CF perceived lower risk of negative outcomes associated with using e-cigarettes and smoked marijuana compared to combustible cigarettes. Ever-use was correlated with a lower perception of risk across all products. CF providers estimated lower rates of product use in their own patients compared to both the general AYA CF population and the general AYA population, and estimated lower use among the general CF AYA population compared to the general AYA population. Receipt of avoidance education varied greatly when comparing AYAs with CF, parents of individuals with CF, and CF healthcare providers. Reasons for undereducation include but are not limited to lack of familiarity with products, assumption of avoidance, assumption of education, and time constraints.

CONCLUSIONS

Findings concerning safety perceptions and use of combustible tobacco, e-cigarettes, and marijuana in individuals with cystic fibrosis underscore the importance of providing avoidance education to vulnerable patient populations. Insight derived from this study may also inform pediatric to adult clinic transition education, when chronic disease populations are at greatest risk for engaging in risky behaviors.

IMPLICATIONS AND CONTRIBUTION

We report data on use, risk perception, and education of cigarettes, electronic cigarettes, and cannabis in individuals with cystic fibrosis, with a focus on adolescents and young adults. Such Findings will inform prevention education, especially during the critical transition period from pediatric to adult care when these behaviors are prevalent.

The impact of e-cigarette exposure on different organ systems: A review of recent evidence and future perspectives

The use of electronic cigarettes (e-cigs) is rapidly increasing worldwide and is promoted as a smoking cessation tool. The impact of traditional cigs on human health has been well-defined in both animal and human studies. In contrast, little is known about the adverse effects of e-cigs exposure on human health. This review summarizes the impact of e-cigs exposure on different organ systems based on the rapidly expanding recent evidence from experimental and human studies. A number of growing studies have shown the adverse effects of e-cigs exposure on various organ systems. The summarized data in this review indicate that while e-cigs use causes less adverse effects on different organs compared to traditional cigs, its long-term exposure may lead to serious health effects. Data on short-term organ effects are limited and there is no sufficient evidence on long-term organ effects. Moreover, the adverse effects of secondhand and third hand e-cigs vapour exposure have not been thoroughly investigated in previous studies. Although some studies demonstrated e-cigs used as a smoking cessation tool, there is a lack of strong evidence to support it. While some researchers suggested e-cigs as a safer alternative to tobacco smoking, their long-term exposure health effects remain largely unknown. Therefore, more epidemiological and prospective studies including mechanistic studies are needed to address the potential adverse health effects of e-cigs to draw a firm conclusion about their safe use. A wide variation in e-cigs products and the lack of standardized testing methods are the major barriers to evaluating the existing data. Specific regulatory guidelines for both e-cigs components and the manufacturing process may be effective to protect consumer health.

Short-term exposure of female BALB/cJ mice to e-cigarette aerosol promotes neutrophil recruitment and enhances neutrophil-platelet aggregation in pulmonary microvasculature

Despite the perception that e-cigarettes are safer than conventional cigarettes, numerous findings demonstrated that e-cigarette aerosol (EC) exposure induced compromised immune functionality, vascular changes even after acute exposure, and lung injury. Notably, altered neutrophil functionality and platelet hemodynamics have been observed post-EC exposure. It was hypothesized that EC exposure initiates an inflammatory response resulting in altered neutrophil behavior and increased neutrophil-platelet interaction in the pulmonary microvasculature. Neutrophil and platelet responses were examined up to 48 hrs following whole-body, short-term EC exposure without flavorants or nicotine in a murine model, which most closely modeled secondhand exposure. This study is the first to investigate the impact of EC exposure through lung intravital imaging. Compared to room air-exposed mice, EC-exposed mice displayed significantly increased 1.7‒1.9-fold number of neutrophils in the pulmonary microvasculature associated with no marked change in neutrophils within whole blood or bronchoalveolar lavage fluid (BALF). Neutrophil-platelet interactions were also significantly elevated 1.9‒2.5-fold in exposed mice. Plasma concentration of myeloperoxidase was markedly reduced 1.5-fold 48 hr following exposure cessation, suggesting suppressed neutrophil antimicrobial activity. Cytokine expression exhibited changes indicating vascular damage. Effects persisted for 48 hr post-EC exposure. Data demonstrated that EC exposure repeated for 3 consecutive days in 2.5 hr intervals in the absence of flavorants or nicotine resulted in modified pulmonary vasculature hemodynamics, altered immune functionality, and a pro-inflammatory state in female BALB/cJ mice.

Molecular insights into the role of electronic cigarettes in oral carcinogenesis

Electronic cigarette (EC) usage or vaping has seen a significant rise in recent years across various parts of the world. They have been publicized as a safe alternative to smoking; however, this is not supported strongly by robust research evidence. Toxicological analysis of EC liquid and aerosol has revealed presence of several toxicants with known carcinogenicity. Oral cavity is the primary site of exposure of both cigarette smoke and EC aerosol. Role of EC in oral cancer is not as well-researched as that of traditional smoking. However, several recent studies have shown that it can lead to a wide range of potentially carcinogenic molecular events in oral cells. This review delineates the oral carcinogenesis potential of ECs at the molecular level, providing a summary of the effects of EC usage on cancer therapy resistance, cancer stem cells (CSCs), immune evasion, and microbiome dysbiosis, all of which may lead to increased tumor malignancy and poorer patient prognosis. This review of literature indicates that ECs may not be as safe as they are perceived to be, however further research is needed to definitively determine their oncogenic potential.

Smoking cessation and vaccination

A significant proportion of COPD patients (∼40%) continue smoking despite knowing that they have the disease. Smokers with COPD exhibit higher levels of nicotine dependence, and have lower self-efficacy and self-esteem, which affects their ability to quit smoking. Treatment should be adapted to the needs of individual patients with different levels of tobacco dependence. The combination of counselling plus pharmacotherapy is the most effective cessation treatment for COPD. In patients with severe COPD, varenicline and bupropion have been shown to have the highest abstinence rates compared with nicotine replacement therapy. There is a lack of evidence to support that smoking cessation reduction or harm reduction strategies have benefits in COPD patients. The long-term efficacy and safety of electronic cigarettes for smoking cessation need to be evaluated in high-risk populations; therefore, it is not possible to recommend their use for smoking cessation in COPD. Future studies with the new generation of nicotine vaccines are necessary to determine their effectiveness in smokers in general and in COPD patients.

The relationship between the use of electronic nicotine delivery systems (ENDS) and effects on pulmonary immune responses-a literature review

INTRODUCTION

The use of electronic nicotine delivery systems (ENDS), or vaping, is a relatively recent phenomenon, and there are various gaps in our current knowledge regarding the specific effects of e-cigarettes, such as their immunological effects. The importance of this question became even more relevant in light of the COVID-19 pandemic.

OBJECTIVE

This literature review examines the relationship between the use of electronic nicotine delivery systems (ENDS) and immunological effects to examine available information and identify gaps in the current knowledge. Our search strategy included studies focusing on the effects of ENDS on the immune response during infectious respiratory diseases such as COVID-19 and pneumonia.

METHODS

Peer-reviewed studies presenting quantitative data published from 2007, the year that e-cigarettes were introduced to the US market until 2022 have been included. All studies were indexed in PubMed. We excluded papers on THC and EVALI (E-cigarette, or Vaping Product, Use Associated Lung Injury) as we wanted to focus on the effects of nicotine devices.

RESULTS

Among the 21 articles that assessed the relationship between ENDS and immunological health effects, we found eight studies based on cell models, two articles based on both cell and mouse models, five articles based on mouse models, and six studies of human populations. Most of the articles identified in our review demonstrated a potential association between vaping and adverse immunological health effects.

DISCUSSION

Overall, the evidence from the cell and animal studies indicates that there is a positive, statistically significant association between vaping and adverse immune response during infectious respiratory diseases. The evidence from human studies is not conclusive.

Aerosolized nicotine from e-cigarettes alters gene expression, increases lung protein permeability, and impairs viral clearance in murine influenza infection

E-cigarette use has rapidly increased as an alternative means of nicotine delivery by heated aerosolization. Recent studies demonstrate nicotine-containing e-cigarette aerosols can have immunosuppressive and pro-inflammatory effects, but it remains unclear how e-cigarettes and the constituents of e-liquids may impact acute lung injury and the development of acute respiratory distress syndrome caused by viral pneumonia. Therefore, in these studies, mice were exposed one hour per day over nine consecutive days to aerosol generated by the clinically-relevant tank-style Aspire Nautilus aerosolizing e-liquid containing a mixture of vegetable glycerin and propylene glycol (VG/PG) with or without nicotine. Exposure to the nicotine-containing aerosol resulted in clinically-relevant levels of plasma cotinine, a nicotine-derived metabolite, and an increase in the pro-inflammatory cytokines IL-17A, CXCL1, and MCP-1 in the distal airspaces. Following the e-cigarette exposure, mice were intranasally inoculated with influenza A virus (H1N1 PR8 strain). Exposure to aerosols generated from VG/PG with and without nicotine caused greater influenza-induced production in the distal airspaces of the pro-inflammatory cytokines IFN-γ, TNFα, IL-1β, IL-6, IL-17A, and MCP-1 at 7 days post inoculation (dpi). Compared to the aerosolized carrier VG/PG, in mice exposed to aerosolized nicotine there was a significantly lower amount of Mucin 5 subtype AC (MUC5AC) in the distal airspaces and significantly higher lung permeability to protein and viral load in lungs at 7 dpi with influenza. Additionally, nicotine caused relative downregulation of genes associated with ciliary function and fluid clearance and an increased expression of pro-inflammatory pathways at 7 dpi. These results show that (1) the e-liquid carrier VG/PG increases the pro-inflammatory immune responses to viral pneumonia and that (2) nicotine in an e-cigarette aerosol alters the transcriptomic response to pathogens, blunts host defense mechanisms, increases lung barrier permeability, and reduces viral clearance during influenza infection. In conclusion, acute exposure to aerosolized nicotine can impair clearance of viral infection and exacerbate lung injury, findings that have implications for the regulation of e-cigarette products.

Influence of puff topographies on e-liquid heating temperature, emission characteristics and modeled lung deposition of Puff Bar™

Puff Bar™, one of the latest designs of e-cigarettes, heats a mixture of liquid using a battery-powered coil at certain temperatures to emit aerosol. This study presents a mass-based characterization of emissions from seven flavors of Puff Bar™ devices by aerosolizing with three puff topographies [(puff volume: 55 < 65 < 75-mL) within 4-seconds at 30-seconds interval]. We evaluated the effects of puff topographies on heating temperatures; characterized particles using a cascade impactor; and measured volatile carbonyl compounds (VCCs). Modeled dosimetry and calculated mass median aerodynamic diameters (MMADs) were used to estimate regional, total respiratory deposition of the inhaled aerosol and exhaled fractions that could pose secondhand exposure risk. Temperatures of Puff Bar™ e-liquids increased with increasing puff volumes: 55mL (116.6 °C), 65 mL (128.3 °C), and 75mL (168.9 °C). Flavor types significantly influenced MMADs, total mass of particles, and VCCs (μg/puff: 2.15-2.30) in Puff Bar™ emissions (p < 0.05). Increasing puff volume (mL:55 < 65 < 75) significantly increased total mass (mg/puff: 4.6 < 5.6 < 6.2) of particles without substantially changing MMADs (~1μm:1.02~0.99~0.98). Aerosol emissions were estimated to deposit in the pulmonary region of e-cigarette user (41-44%), which could have toxicological importance. More than 2/3 (67-77%) of inhaled particles were estimated to be exhaled by users, which could affect bystanders. The VCCs measured contained carcinogens-formaldehyde (29.6%) and acetaldehyde (16.4%)-as well as respiratory irritants: acetone (23.9%), isovaleraldehyde (14.5%), and acrolein (4.9%). As Puff Bar™ emissions contain respirable particles and harmful chemicals, efforts should be made to minimize exposures, especially in indoor settings where people (including vulnerable populations) spend most of their life-time.

Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers

Objective

The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology.

Conclusions

Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers.

Implications for Practice

Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.

E-cigarette aerosol impairs male mouse skeletal muscle force development and prevents recovery from injury

To date, there has been a lag between the rise in E-cigarette use and an understanding of the long-term health effects. Inhalation of E-cigarette aerosol delivers high doses of nicotine, raises systemic cytokine levels, and compromises cardiopulmonary function. The consequences for muscle function have not been thoroughly investigated. The present study tests the hypothesis that exposure to nicotine-containing aerosol impairs locomotor muscle function, limits exercise tolerance, and interferes with muscle repair in male mice. Nicotine-containing aerosol reduced the maximal force produced by the extensor digitorum longus (EDL) by 30%-40% and, the speed achieved in treadmill running by 8%. Nicotine aerosol exposure also decreased adrenal and increased plasma epinephrine and norepinephrine levels, and these changes in catecholamines manifested as increased muscle and liver glycogen stores. In nicotine aerosol exposed mice, muscle regenerating from overuse injury only recovered force to 80% of noninjured levels. However, the structure of neuromuscular junctions (NMJs) was not affected by e-cigarette aerosols. Interestingly, the vehicle used to dissolve nicotine in these vaping devices, polyethylene glycol (PG) and vegetable glycerin (VG), decreased running speed by 11% and prevented full recovery from a lengthening contraction protocol (LCP) injury. In both types of aerosol exposures, cardiac left ventricular systolic function was preserved, but left ventricular myocardial relaxation was altered. These data suggest that E-cigarette use may have a negative impact on muscle force and regeneration due to compromised glucose metabolism and contractile function in male mice.NEW & NOTEWORTHY In male mice, nicotine-containing E-cigarette aerosol compromises muscle contractile function, regeneration from injury, and whole body running speeds. The vehicle used to deliver nicotine, propylene glycol, and vegetable glycerin, also reduces running speed and impairs the restoration of muscle function in injured muscle. However, the predominant effects of nicotine in this inhaled aerosol are evident in altered catecholamine levels, increased glycogen content, decreased running capacity, and impaired recovery of force following an overuse injury.

Electronic Cigarettes: A Pro-Con Review of the Current Literature

Electronic cigarettes (e-cigarettes, e-cigs, or electronic nicotine delivery systems) are battery-operated devices typically containing glycerol and/or propylene glycol-based solutions with varying nicotine content, known as e-liquids. Although e-cigarettes were originally developed as a potentially less harmful alternative to traditional combustible tobacco cigarette smokers, several factors have driven their popularity among smokers and nonsmokers alike, including their sleek product designs, innumerable appealing flavors, lack of combustible smoke and odor, and high potential nicotine concentrations. Furthermore, many advocates have promoted the idea that e-cigarettes are safe to use, or at least safer than conventional tobacco, despite limited longitudinal data to support these claims. Here, we examine what is known about the impacts of e-cigarette use on traditional cigarette smoking cessation, lung health, and youth and young adult tobacco product exposure. Upon review of the currently available literature, the negative effects of e-cigarette use seem to outweigh any potential benefit, because the available evidence does not confirm the use of e-cigarettes as an effective strategy for supporting traditional combustible tobacco cigarette smoking cessation, particularly given the emerging adverse effects on lung health and the potential future public health effects of e-cigarette adoption among a burgeoning new generation of tobacco product users.

Association of e-Cigarette Exposure with Pediatric Otitis Media Recurrence

OBJECTIVE

Otitis media (OM) is a common inflammatory disease spectrum in children and a leading cause of pediatric physician visits, antibiotic prescriptions and surgery. Tobacco exposure is associated with increased risk of OM recurrence, chronicity and surgeries. Tobacco products have changed dramatically in recent years with the advent of electronic cigarettes (e-cigarettes). While users frequently perceive vape as less harmful than traditional cigarettes, burgeoning evidence supports its contribution to respiratory pathologies. The consequences of secondhand exposure, particularly among children, are understudied. The aim of this study was to examine the association of e-cigarette emissions (EE) with OM recurrence and surgeries in the US.

METHODS

Questionnaire data regarding ear infections and tobacco exposure was gathered for all pediatric respondents of the National Health and Nutrition Examination Survey (NHANES) 2017 to 2018. Weighted analyzes and logistic regression models were used to assess associations.

RESULTS

Data was available for 2022 participants (aged 6-17); all were included for analyzes. Tobacco exposure was observed in 42%; 9% were exposed to EE. EE contributed to risk of ≥3 ear infections (OR = 1.61, 95% CI 1.01-2.58, P = .047). After adjustment for significant covariates (race and asthma), the association fell below significance (P = .081). No other significant associations were observed between ear infections, or tympanostomy tube insertion and exposure variables (EE, gestational or other household exposure).

CONCLUSIONS

Exposure to EE may confer greater risk of pediatric OM than previously identified factors such as household smoke, or gestational exposure. Further investigation of EE and its health implications in children is warranted.

LEVEL OF EVIDENCE

IV.

A Systematic Review of the Literature Examining the Effects of Cigarette Smoke and e-Cigarette Vapor on the Virulence of Human Pathogenic Bacteria

The bioactive chemicals in cigarette smoke (CS) and e-cigarette vapor (EV) may affect pathogenic bacteria in the nasopharyngeal microflora, which may have implications on the pathophysiology of respiratory infections in cigarette smokers and e-cigarette users. In this systematic review, we seek to synthesize the research evidence supporting this hypothesis. To address the central research question, "what is known from the published, peer-reviewed literature about the effects of cigarette smoke or e-cigarette vapor exposure on the physiology of human pathogenic bacteria?", we screened the PubMed®, Web of ScienceTM, and ScienceDirect databases for reports examining the virulence characteristics and gene expression in human pathogenic bacteria exposed to either CS or EV. The principal conclusion from our analysis is that exposure to either CS or EV induces the virulence of respiratory pathogenic bacteria in a strain-dependent manner, which may in turn facilitate respiratory infections in cigarette smokers and e-cigarette users. In addition, we present evidence that nicotine and reactive oxygen species are the main chemicals responsible for CS/EV-mediated alterations in bacterial physiology. We note limitations that this review does not examine reports describing the alterations in host respiratory physiology or nasopharyngeal dysbiosis caused by CS/EV exposure. Future research to determine whether CS/EV-mediated augmentation of bacterial virulence indeed plays a role in human respiratory tract infections is warranted.

Vegetable glycerin e-cigarette aerosols cause airway inflammation and ion channel dysfunction

Vegetable glycerin (VG) and propylene glycol (PG) serve as delivery vehicles for nicotine and flavorings in most e-cigarette (e-cig) liquids. Here, we investigated whether VG e-cig aerosols, in the absence of nicotine and flavors, impact parameters of mucociliary function in human volunteers, a large animal model (sheep), and air-liquid interface (ALI) cultures of primary human bronchial epithelial cells (HBECs). We found that VG-containing (VG or PG/VG), but not sole PG-containing, e-cig aerosols reduced the activity of nasal cystic fibrosis transmembrane conductance regulator (CFTR) in human volunteers who vaped for seven days. Markers of inflammation, including interleukin-6 (IL6), interleukin-8 (IL8) and matrix metalloproteinase-9 (MMP9) mRNAs, as well as MMP-9 activity and mucin 5AC (MUC5AC) expression levels, were also elevated in nasal samples from volunteers who vaped VG-containing e-liquids. In sheep, exposures to VG e-cig aerosols for five days increased mucus concentrations and MMP-9 activity in tracheal secretions and plasma levels of transforming growth factor-beta 1 (TGF-β1). In vitro exposure of HBECs to VG e-cig aerosols for five days decreased ciliary beating and increased mucus concentrations. VG e-cig aerosols also reduced CFTR function in HBECs, mechanistically by reducing membrane fluidity. Although VG e-cig aerosols did not increase MMP9 mRNA expression, expression levels of IL6, IL8, TGFB1, and MUC5AC mRNAs were significantly increased in HBECs after seven days of exposure. Thus, VG e-cig aerosols can potentially cause harm in the airway by inducing inflammation and ion channel dysfunction with consequent mucus hyperconcentration.

A critical review on air pollutant exposure and age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of visual impairments and blindness worldwide in the elderly and its incidence strongly increases with ages. The etiology of AMD is complex and attributed to the genetic modifiers, environmental factors and gene-environment interactions. Recently, the impacts of air pollution on the development of eye diseases have become the new area of focus, and disordered air exposure combined with inadequate health management has caused problems for the eye health, such as dry eye, glaucoma, and retinopathy, while its specific role in the occurrence of AMD is still not well understood. In order to summarize the progress of this research field, we performed a critical review to summarize the epidemiological and mechanism evidence on the association between air pollutants exposure and AMD. This review documented that exposure to air pollutants will accelerate or worsen the morbidity and prevalence of AMD. Air pollutants exposure may change the homeostasis, interfere with the inflammatory response, and take direct action on the lipid metabolism and oxidative stress in the macula. More attention should be given to understanding the impact of ambient air pollution on AMD worldwide.

E-cigarettes and youth: an unresolved Public Health concern

The use of electronic cigarettes (e-cigarette) and vaping devices started as a potential aid for cessation and reducing the harmful consequences of cigarette smoking, mainly in the adult population. Today e-cigarette use is highly increasing in vulnerable populations, especially young and pregnant women, due to the misconception of its harmless use.

Despite the growing acknowledgment in e-cigarette as a potential harmful device, and due to mixed information found concerning its beneficial aid for smokers, along with an insufficient clinical study done in human models, it is important to further evaluate the possible benefits and risks of non-combusting, vaping nicotine or non-nicotine delivery devices.

In this review we tried to summarize the latest updated information found in the literature, concentrating mainly in the variety of adverse effects of e-cigarette use and its contribution for recent and future health concerns.

Systematic review of changed smoking behaviour, smoking cessation and psychological states of smokers according to cigarette type during the COVID-19 pandemic

OBJECTIVES

Although the global COVID-19 pandemic has increased interest in research involving high-risk smokers, studies examining changed smoking behaviours, cessation intentions and associated psychological states among smokers are still scarce. This study aimed to systematically review the literature related to this subject.

DESIGN

A systematic review of published articles on cigarettes and COVID-19-related topics DATA SOURCES: Our search was conducted in January 2021. We used the keywords COVID-19, cigarettes, electronic cigarettes (e-cigarettes) and psychological factors in PubMed and ScienceDirect and found papers published between January and December 2020.

DATA SELECTION

We included articles in full text, written in English, and that surveyed adults. The topics included smoking behaviour, smoking cessation, psychological state of smokers and COVID-19-related topics.

DATA EXTRACTION AND SYNTHESIS

Papers of low quality, based on quality assessment, were excluded. Thirteen papers were related to smoking behaviour, nine papers were related to smoking cessation and four papers were related to psychological states of smokers.

RESULTS

Owing to the COVID-19 lockdown, cigarette users were habituated to purchasing large quantities of cigarettes in advance. Additionally, cigarette-only users increased their attempts and willingness to quit smoking, compared with e-cigarette-only users.

CONCLUSIONS

Owing to the COVID-19 outbreak, the intention to quit smoking was different among smokers, according to cigarette type (cigarette-only users, e-cigarette-only users and dual users). With the ongoing COVID-19 pandemic, policies and campaigns to increase smoking cessation intentions and attempts to quit smoking among smokers at high risk of COVID-19 should be implemented. Additionally, e-cigarette-only users with poor health-seeking behaviour require interventions to increase the intention to quit smoking.

Effects of mango and mint pod-based e-cigarette aerosol inhalation on inflammatory states of the brain, lung, heart, and colon in mice

While health effects of conventional tobacco are well defined, data on vaping devices, including one of the most popular e-cigarettes which have high nicotine levels, are less established. Prior acute e-cigarette studies have demonstrated inflammatory and cardiopulmonary physiology changes while chronic studies have demonstrated extra-pulmonary effects, including neurotransmitter alterations in reward pathways. In this study we investigated the impact of inhalation of aerosols produced from pod-based, flavored e-cigarettes (JUUL) aerosols three times daily for 3 months on inflammatory markers in the brain, lung, heart, and colon. JUUL aerosol exposure induced upregulation of cytokine and chemokine gene expression and increased HMGB1 and RAGE in the nucleus accumbens in the central nervous system. Inflammatory gene expression increased in the colon, while gene expression was more broadly altered by e-cigarette aerosol inhalation in the lung. Cardiopulmonary inflammatory responses to acute lung injury with lipopolysaccharide were exacerbated in the heart. Flavor-specific findings were detected across these studies. Our findings suggest that daily e-cigarette use may cause neuroinflammation, which may contribute to behavioral changes and mood disorders. In addition, e-cigarette use may cause gut inflammation, which has been tied to poor systemic health, and cardiac inflammation, which leads to cardiovascular disease.

A Comparison of Haitian and American Bachelor of Science in Nursing Students' Perceptions of Cigarette Smoking and E-Cigarette Use

ABSTRACT

Cigarette smoking is a global health epidemic, and smoking along with electronic nicotine delivery systems use or vaping are on the rise. Despite the effectiveness of smoking cessation strategies, healthcare providers and nursing students do not routinely recommend these strategies for patients who are smokers. This study compares the perceptions of smoking and vaping between two groups of baccalaureate degree nursing students from Haiti and the United States. The study was influenced by contemporary and past studies showing that more young people are drawn into smoking and vaping despite the prevalence of antismoking policies and awareness campaigns. In this descriptive study, surveys were used to collect data to determine the differences between the two country's nursing students on their perception of smoking and vaping. The findings indicated that, despite greater usage, the students from the United States had a higher perception of the health implications of cigarette smoking and vaping compared with those from Haiti. On the basis of the findings of this study, collaborative pedagogical research opportunities among international nursing education programs can further curriculum development to foster growth and development of future global health practitioners.

Predicting the pulmonary effects of long-term e-cigarette use: are the clouds clearing?

Commercially available since 2007, e-cigarettes are a popular electronic delivery device of ever-growing complexity. Given their increasing use by ex-smokers, smokers and never-smokers, it is important to evaluate evidence of their potential pulmonary effects and predict effects of long-term use, since there has been insufficient time to study a chronic user cohort. It is crucial to evaluate indicators of harm seen in cigarette use, and those potentially unique to e-cigarette exposure. Evaluation must also account for the vast variation in e-cigarette devices (now including at least five generations of devices) and exposure methods used in vivo and in vitroThus far, short-term use cohort studies, combined with in vivo and in vitro models, have been used to probe for the effects of e-cigarette exposure. The effects and mechanisms identified, including dysregulated inflammation and decreased pathogen resistance, show concerning overlaps with the established effects of cigarette smoke exposure. Additionally, research has identified a signature of dysregulated lipid processing, which is unique to e-cigarette exposure.This review will evaluate the evidence of pulmonary effects of, and driving mechanisms behind, e-cigarette exposure, which have been highlighted in emerging literature, and highlight the gaps in current knowledge. Such a summary allows understanding of the ongoing debate into e-cigarette regulation, as well as prediction and potential mitigation of future problems surrounding e-cigarette use.

Time-Specific Factors Influencing the Development of Asthma in Children

Susceptibility to asthma is complex and heterogeneous, as it involves both genetic and environmental insults (pre- and post-birth) acting in a critical window of development in early life. According to the Developmental Origins of Health and Disease, several factors, both harmful and protective, such as nutrition, diseases, drugs, microbiome, and stressors, interact with genotypic variation to change the capacity of the organism to successfully adapt and grow in later life. In this review, we aim to provide the latest evidence about predictive risk and protective factors for developing asthma in different stages of life, from the fetal period to adolescence, in order to develop strategic preventive and therapeutic interventions to predict and improve health later in life. Our study shows that for some risk factors, such as exposure to cigarette smoke, environmental pollutants, and family history of asthma, the evidence in favor of a strong association of those factors with the development of asthma is solid and widely shared. Similarly, the clear benefits of some protective factors were shown, providing new insights into primary prevention. On the contrary, further longitudinal studies are required, as some points in the literature remain controversial and a source of debate.

Assessing variability of aerosols generated from e-Cigarettes

While some in vitro and in vivo experiments have studied the toxic effects of e-cigarette (e-cig) components, the typical aerosol properties released from e-cigarettes have not been well characterized. In the present study, we characterized the variability in mass concentration and particle size distribution associated with the aerosol generation of different devices and e-liquid compositions in an experimental setup. The findings of this study indicate a large inter-day variability in the experiments, likely due to poor quality control in some e-cig devices, pointing to the need for a better understanding of all the factors affecting exposures in in vitro and in vivo experiments, and the development of standardized protocols for generation and measurement of e-cig aerosols.

Vaping-Associated Lung Injury: A Review

Since commercial development in 2003, the usage of modern electronic cigarette (e-cigarette) continues to increase amongst people who have never smoked, ex-smokers who have switched to e-cigarettes, and dual-users of both conventional cigarettes and e-cigarettes. With such an increase in use, knowledge of the irritative, toxic and potential carcinogenic effects on the lungs is increasing. This review article will discuss the background of e-cigarettes, vaping devices and explore their popularity. We will further summarise the available literature describing the mechanism of lung injury caused by e-cigarette or vaping use.

Differential impact of JUUL flavors on pulmonary immune modulation and oxidative stress responses in male and female mice

JUUL is a popular e-cigarette brand that manufactures e-liquids in a variety of flavors, such as mango and mint. Despite their popularity, the pulmonary effects of flavored JUUL e-liquids that are aerosolized and subsequently inhaled are not known. Therefore, the purpose of this study was to evaluate if acute exposure to JUUL e-cigarette aerosols in three popular flavors elicits an immunomodulatory or oxidative stress response in mice. We first developed a preclinical model that mimics human use patterns of e-cigarettes using 1 puff/min or 4 puffs/min exposure regimes. Based on cotinine levels, these exposures were representative of light/occasional and moderate JUUL users. We then exposed C57BL/6 mice to JUUL e-cigarette aerosols in mango, mint, and Virginia tobacco flavors containing 5% nicotine for 3 days, and assessed the inflammatory and oxidative stress response in the lungs and blood. In response to the 1 puff/min regime (light/occasional user), there were minimal changes in BAL cell composition or lung mRNA expression. However, at 4 puffs/min (moderate user), mint-flavored JUUL significantly increased lung neutrophils, while mango-flavored JUUL significantly increased Tnfα and Il13 mRNA in the lungs. Both the 1- and 4 puffs/min regimes significantly increased oxidative stress markers in the blood, indicating systemic effects. Thus, JUUL products are not inert; even short-term inhalation of flavored JUUL e-cigarette aerosols differentially causes immune modulation and oxidative stress responses.