α-Tocopherol Pharmacokinetics in Adults with Cystic Fibrosis: Benefits of Supplemental Vitamin C Administration.

BACKGROUND: Numerous abnormalities in cystic fibrosis (CF) could influence tocopherol absorption, transportation, storage, metabolism and excretion. We hypothesized that the oxidative distress due to inflammation in CF increases vitamin E utilization, which could be positively influenced by supplemental vitamin C administration. METHODS: Immediately before and after receiving vitamin C (500 mg) twice daily for 3.5 weeks, adult CF patients (n = 6) with moderately advanced respiratory tract (RT) disease consumed a standardized breakfast with 30% fat and a capsule containing 50 mg each hexadeuterium (d6)-α- and dideuterium (d2)-γ-tocopheryl acetates. Blood samples were taken frequently up to 72 h; plasma tocopherol pharmacokinetics were determined. During both trials, d6-α- and d2-γ-tocopherols were similarly absorbed and reached similar maximal plasma concentrations ~18-20 h. As predicted, during vitamin C supplementation, the rates of plasma d6-α-tocopherol decline were significantly slower. CONCLUSIONS: The vitamin C-induced decrease in the plasma disappearance rate of α-tocopherol suggests that vitamin C recycled α-tocopherol, thereby augmenting its concentrations. We conclude that some attention should be paid to plasma ascorbic acid concentrations in CF patients, particularly to those individuals with more advanced RT inflammatory disease and including those with severe exacerbations.

Assessing the role of the universal addition of CT thorax to CT abdomen and pelvis in the COVID era. A retrospective multicentre cohort study.

OBJECTIVE: The SARS-CoV2 infection is associated with high mortality for individuals who undergo emergency surgery. The United Kingdom surgical associations and Colleges of Surgeons collectively recommended the addition of CT Thorax to all emergency CT abdomen/pelvis imaging in order to help identify possible COVID-19 patients. Early identification of these patients would lead to optimal treatment strategies for the patient and protection for staff members. However, an extension of CT would be associated with increased irradiation doses for the patient, and its diagnostic relevance was unclear. METHODS: This was a retrospective observational review looking at all surgical admissions that required a CT Thorax/Abdomen/Pelvis across 7 weeks during the COVID-19 pandemic, across four Scottish Hospitals. CT thorax investigations (of non-surgical patients) were also re-assessed by a single radiologist to assess the extent of pathology identified at the lung bases (and therefore would be included in a standard CT abdomen and pelvis). RESULTS: Of 216 patients identified who had a CT thorax/Abdomen/Pelvis during the timeframe, 5 were diagnosed with COVID-19. During this timeframe, 77 patients underwent solely CT thorax. Across the entire cohort, 98% of COVID pathology was identified at the lung bases. The estimated sensitivity and specificity of CT thorax was 60 and 86.4% respectively. CONCLUSIONS: In a region with relatively low prevalence of SARS-COV2 infection, inclusion of CT Thorax in surgical admission imaging does not significantly contribute to identification and management of SARS-COV2 patients. We therefore suggest that imaging the lung bases can be sufficient to raise clinical suspicion of COVID-19. ADVANCES IN KNOWLEDGE: This paper adds further evidence to that from other single UK centres that the addition of CT chest for all patients does not yield any further diagnostic information regarding coronavirus. Additionally, rapid SARS-CoV-2 testing in the UK (which is currently widely available) further demonstrates that inclusion of the entire chest during CT examination of the acute abdomen is not required.

Quantitative assessment of cyanide in cystic fibrosis sputum and its oxidative catabolism by hypochlorous acid.

RATIONALE: Cystic fibrosis (CF) patients are known to produce cyanide (CN-) although challenges exist in determinations of total levels, the precise bioactive levels, and specificity of its production by CF microflora, especially P. aeruginosa. Our objective was to measure total CN- levels in CF sputa by a simple and novel technique in P. aeruginosa positive and negative adult patients, to review respiratory tract (RT) mechanisms for the production and degradation of CN-, and to interrogate sputa for post-translational protein modification by CN- metabolites. METHODS: Sputa CN- concentrations were determined by using a commercially available CN- electrode, measuring levels before and after addition of cobinamide, a compound with extremely high affinity for CN-. Detection of protein carbamoylation was measured by Western blot. MEASUREMENTS AND MAIN RESULTS: The commercial CN- electrode was found to overestimate CN- levels in CF sputum in a highly variable manner; cobinamide addition rectified this analytical issue. Although P. aeruginosa positive patients tended to have higher total CN- values, no significant differences in CN- levels were found between positive and negative sputa. The inflammatory oxidant hypochlorous acid (HOCl) was shown to rapidly decompose CN-, forming cyanogen chloride (CNCl) and the carbamoylating species cyanate (NCO-). Carbamoylated proteins were found in CF sputa, analogous to reported findings in asthma. CONCLUSIONS: Our studies indicate that CN- is a transient species in the inflamed CF airway due to multiple biosynthetic and metabolic processes. Stable metabolites of CN-, such as cyanate, or carbamoylated proteins, may be suitable biomarkers of overall CN- production in CF airways.

A Multicenter Randomized Controlled Trial of Zephyr Endobronchial Valve Treatment in Heterogeneous Emphysema (LIBERATE).

RATIONALE: This is the first multicenter randomized controlled trial to evaluate the effectiveness and safety of Zephyr Endobronchial Valve (EBV) in patients with little to no collateral ventilation out to 12 months. OBJECTIVES: To evaluate the effectiveness and safety of Zephyr EBV in heterogeneous emphysema with little to no collateral ventilation in the treated lobe. METHODS: Subjects were enrolled with a 2:1 randomization (EBV/standard of care [SoC]) at 24 sites. Primary outcome at 12 months was the ΔEBV-SoC of subjects with a post-bronchodilator FEV1 improvement from baseline of greater than or equal to 15%. Secondary endpoints included absolute changes in post-bronchodilator FEV1, 6-minute-walk distance, and St. George's Respiratory Questionnaire scores. MEASUREMENTS AND MAIN RESULTS: A total of 190 subjects (128 EBV and 62 SoC) were randomized. At 12 months, 47.7% EBV and 16.8% SoC subjects had a ΔFEV1 greater than or equal to 15% (P < 0.001). ΔEBV-SoC at 12 months was statistically and clinically significant: for FEV1, 0.106 L (P < 0.001); 6-minute-walk distance, +39.31 m (P = 0.002); and St. George's Respiratory Questionnaire, -7.05 points (P = 0.004). Significant ΔEBV-SoC were also observed in hyperinflation (residual volume, -522 ml; P < 0.001), modified Medical Research Council Dyspnea Scale (-0.8 points; P < 0.001), and the BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index (-1.2 points). Pneumothorax was the most common serious adverse event in the treatment period (procedure to 45 d), in 34/128 (26.6%) of EBV subjects. Four deaths occurred in the EBV group during this phase, and one each in the EBV and SoC groups between 46 days and 12 months. CONCLUSIONS: Zephyr EBV provides clinically meaningful benefits in lung function, exercise tolerance, dyspnea, and quality of life out to at least 12 months, with an acceptable safety profile in patients with little or no collateral ventilation in the target lobe. Clinical trial registered with www.clinicaltrials.gov (NCT 01796392).

Safety and Clinical Utility of Flexible Bronchoscopic Cryoextraction in Patients With Non-neoplasm Tracheobronchial Obstruction: A Retrospective Chart Review.

BACKGROUND: Airway obstruction from blood clots, airway secretions, and foreign bodies is a potentially life-threatening condition. Optimal management of this problem, whether by rigid or flexible bronchoscopy, has not been well studied. We report our single-center experience on the safety and clinical utility of cryoprobe extraction for this indication. METHODS: We performed a retrospective chart review from January 2006 to November 2014 of all subjects aged 18 and older who underwent flexible bronchoscopic cryoprobe extraction. Subjects with obstruction due to benign or malignant neoplasm or airway stenosis were excluded. RESULTS: A total of 38 cryotherapy sessions performed on 30 subjects were identified for inclusion. Cryoprobe extraction was successful in reestablishing airway patency in 32/38 (84%) sessions overall and in 24/26 (92%) for blood clots, 4/6 (67%) for mucous plugging, 2/4 (50%) for foreign bodies, and 2/2 (100%) for plastic bronchitis. Twenty-one of 31 (68%) sessions resulted in improvement in oxygenation or ventilation. There was 1 complication related to sedation. CONCLUSIONS: We conclude that flexible bronchoscopic cryoprobe extraction of blood clots, mucous secretions, plastic bronchitis, and foreign bodies is a safe and effective option. It can be safely performed at the bedside and in many cases eliminates the need for rigid bronchoscopy.

Discovery and Longitudinal Evaluation of Candidate Protein Biomarkers for Disease Recurrence in Prostate Cancer.

When compared with hormonal therapy alone, treatment with combined hormone and radiation therapy (CHRT) gives improved disease-specific survival outcomes for patients with prostate cancer; however, a significant number of CHRT patients still succumb to recurrent disease. The purpose of this study was to use longitudinal patient samples obtained as part of an ongoing noninterventional clinical trial (ICORG06-15) to identify and evaluate a potential serum protein signature of disease recurrence. Label-free LC-MS/MS based protein discovery was undertaken on depleted serum samples from CHRT patients who showed evidence of disease recurrence (n = 3) and time-matched patient controls (n = 3). A total of 104 proteins showed a significant change between these two groups. Multiple reaction monitoring (MRM) assays were designed for a subset of these proteins as part of a panel of putative prostate cancer biomarkers (41 proteins) for evaluation in longitudinal serum samples. These data revealed significant interpatient variability in individual protein expression between time of diagnosis, disease recurrence, and beyond and serve to highlight the importance of longitudinal patient samples for evaluating the use of candidate protein biomarkers in disease monitoring.

Inflammation, oxidative stress, and cardiovascular disease risk factors in adults with cystic fibrosis.

Cystic fibrosis (CF) represents one of a number of localized lung and non-lung diseases with an intense chronic inflammatory component associated with evidence of systemic oxidative stress. Many of these chronic inflammatory diseases are accompanied by an array of atherosclerotic processes and cardiovascular disease (CVD), another condition strongly related to inflammation and oxidative stress. As a consequence of a dramatic increase in long-lived patients with CF in recent decades, the specter of CVD must be considered in these patients who are now reaching middle age and beyond. Buttressed by recent data documenting that CF patients exhibit evidence of endothelial dysfunction, a recognized precursor of atherosclerosis and CVD, the spectrum of risk factors for CVD in CF is reviewed here. Epidemiological data further characterizing the presence and extent of atherogenic processes in CF patients would seem important to obtain. Such studies should further inform and offer mechanistic insights into how other chronic inflammatory diseases potentiate the processes leading to CVDs.

Cerebral gas embolism in a case of Influenza A-associated acute respiratory distress syndrome treated with high-frequency oscillatory ventilation.

A 22-year-old obese asthmatic woman with Influenza A (H1N1)-associated acute respiratory distress syndrome died from cerebral artery gas emboli with massive cerebral infarction while being treated with High-Frequency Oscillatory Ventilation in the absence of a right to left intracardiac shunt. We review and briefly discuss other causes of systemic gas emboli (SGE). We review proposed mechanisms of SGE, their relation to our case, and how improved understanding of the risk factors may help prevent SGE in positive pressure ventilated patients.

Development of a label-free LC-MS/MS strategy to approach the identification of candidate protein biomarkers of disease recurrence in prostate cancer patients in a clinical trial of combined hormone and radiation therapy.

PURPOSE: Combined hormone and radiation therapy (CHRT) is one of the principle curative regimes for localised prostate cancer (PCa). Following treatment, many patients subsequently experience disease recurrence however; current diagnostics tests fail to predict the onset of disease recurrence. Biomarkers that address this issue would be of significant advantage. EXPERIMENTAL DESIGN: Label-free LC-MS/MS for protein biomarker discovery and MRM for targeted confirmation were applied to patient serum samples accrued in a non-interventional clinical trial of CHRT. RESULTS: Analysis of time-matched patient samples from a patient with disease recurrence compared with a time match disease-free individual supported the identification of 287 proteins. Of these, 141 proteins were quantified, 95 proteins changed in their expression (P ≤ 0.05 and ≥1.5-fold change) and of these 16 were selected for MRM confirmation. The protein expression changes observed in the label-free LC-MS/MS and MRM analysis were found to be highly correlated (R(2) = 0.85). CONCLUSIONS AND CLINICAL RELEVANCE: The establishment of a clinical trial to support the acquisition of samples and development of a pipeline for MS-based biomarker discovery and validation should contribute to the identification of a serum protein signature to predict or monitor the outcome of treatment of patients with PCa.

The asthma-chronic obstructive pulmonary disease overlap syndrome: pharmacotherapeutic considerations.

Asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) is a commonly encountered yet loosely defined clinical entity. ACOS accounts for approximately 15-25% of the obstructive airway diseases and patients experience worse outcomes compared with asthma or COPD alone. Patients with ACOS have the combined risk factors of smoking and atopy, are generally younger than patients with COPD and experience acute exacerbations with higher frequency and greater severity than lone COPD. Pharmacotherapeutic considerations require an integrated approach, first to identify the relevant clinical phenotype(s), then to determine the best available therapy. The authors discuss the array of existing and emerging classes of drugs that could benefit those with ACOS and share their therapeutic approach. A consensus international definition of ACOS is needed to design prospective, randomized clinical trials to evaluate specific drug interventions on important outcomes such as lung function, acute exacerbations, quality of life and mortality.

Omics approaches in cystic fibrosis research: a focus on oxylipin profiling in airway secretions.

Cystic fibrosis (CF) is associated with abnormal lipid metabolism, intense respiratory tract (RT) infection, and inflammation, eventually resulting in lung tissue destruction and respiratory failure. The CF RT inflammatory milieu, as reflected by airway secretions, includes a complex array of inflammatory mediators, bacterial products, and host secretions. It is dominated by neutrophils and their proteolytic and oxidative products and includes a wide spectrum of bioactive lipids produced by both host and presumably microbial metabolic pathways. The fairly recent advent of "omics" technologies has greatly increased capabilities of further interrogating this easily obtainable RT compartment that represents the apical culture media of the underlying RT epithelial cells. This paper discusses issues related to the study of CF omics with a focus on the profiling of CF RT oxylipins. Challenges in their identification/quantitation in RT fluids, their pathways of origin, and their potential utility for understanding CF RT inflammatory and oxidative processes are highlighted. Finally, the utility of oxylipin metabolic profiling in directing optimal therapeutic approaches and determining the efficacy of various interventions is discussed.

Metabolomic profiling of regulatory lipid mediators in sputum from adult cystic fibrosis patients.

Retained respiratory tract (RT) secretions, infection, and exuberant inflammatory responses are core abnormalities in cystic fibrosis (CF) lung disease. Factors contributing to the destructive CF airway inflammatory processes remain incompletely characterized. The pro-oxidative inflammatory CF RT milieu is known to contain enzymatically and nonenzymatically produced regulatory lipid mediators, a panel of structurally defined oxidized metabolites of polyunsaturated fatty acids known to play a role in pathology related to inflammation. Using an extraction protocol that maximizes recoveries of sputum-spiked deuterated standards, coupled with an LC/MS/MS detection system, this study presents a metabolomic method to assess a broad spectrum of regulatory lipid mediators in freshly obtained sputum from CF patients. A broad range of both proinflammatory and anti-inflammatory lipid mediators was detected, including PGE2, PGD2, TXB2, LTB4, 6-trans-LTB4, 20-OH-LTB4, 20-COOH-LTB4, 20-HETE, 15-HETE, 11-HETE, 12-HETE, 8-HETE, 9-HETE, 5-HETE, EpETrEs, diols, resolvin E1, 15-deoxy-PGJ2, and LXA4. The vast majority of these oxylipins have not been reported previously in CF RT secretions. Whereas direct associations of individual proinflammatory lipid mediators with compromised lung function (FEV-1) were observed, the relationships were not robust. However, multiple statistical analyses revealed that the regulatory lipid mediators profile taken in aggregate proved to have a stronger association with lung function in relatively stable outpatient adult CF patients. Our data reveal a relative paucity of the anti-inflammatory lipid mediator lipoxin A4 in CF sputum. Patients displaying detectable levels of the anti-inflammatory lipid mediator resolvin E1 demonstrated a better lung function compared to those patients with undetectable levels. Our data suggest that comprehensive metabolomic profiling of regulatory lipid mediators in CF sputum should contribute to a better understanding of the molecular mechanisms underlying CF RT inflammatory pathobiology. Further studies are required to determine the extent to which nutritional or pharmacological interventions alter the regulatory lipid mediators profile of the CF RT and the impact of potential modulations of RT regulatory lipid mediators on the clinical progression of CF lung disease.

Medium-mediated effects increase cell killing in a human keratinocyte cell line exposed to solar-simulated radiation.

PURPOSE: The objective of this study was to investigate whether cell culture medium is a biologically relevant exposure medium that can be employed in non-ionising photobiological investigations. METHODS: The effect of solar-simulated irradiation on cell culture medium and its ability to elicit cell death was studied. The role of reactive oxygen species (ROS), cell secreted factors, and the contribution of individual components of the medium were investigated. RESULTS: Cell death was found to be primarily mediated through the formation of ROS via riboflavin photosensitisation and degradation in the cell culture medium. Phenol red was found to significantly reduce the cell killing ability of riboflavin. Exposures in riboflavin-free medium resulted in significantly increased cell survival compared to identical exposures in riboflavin containing medium. CONCLUSIONS: This study has shown that solar radiation toxicity is augmented by cell culture medium due to the presence of riboflavin. Results suggest that exposures performed in phenol red-free medium may serve to increase phototoxic effects if riboflavin is present. Riboflavin-free media is recommended for solar radiation investigations to eliminate concerns regarding riboflavin photosensitisation and nutrient deprivation.

Evaluation of thiol-based antioxidant therapeutics in cystic fibrosis sputum: Focus on myeloperoxidase.

Neutrophil-dependent reactions catalysed by myeloperoxidase (MPO) are thought to play important roles in the pulmonary pathobiology of cystic fibrosis (CF). Aerosolized thiol antioxidants such as glutathione (GSH) and N-acetylcysteine (NAC) are currently being utilized as therapeutics to modify CF respiratory tract oxidative processes. This study hypothesized that MPO in CF airway lining fluids may be a target of such therapeutics. MPO activity in sputum from 21 adult CF patients was found to be inversely associated with lung function (FEV(1)). In contrast, systemic inflammation (assessed by plasma C-reactive protein) was not correlated with lung function. Ex vivo studies revealed that GSH and NAC effectively scavenged N-chloramines in sputum and inhibited sputum MPO activity with potency exquisitely dependent upon MPO activity levels. Detailed kinetic analyses revealed that NAC and GSH inhibit MPO by distinct mechanisms. Activation of the key pro-inflammatory transcription factor NF-κB in cultured HBE1 cells was inhibited by GSH. The findings reveal that MPO activity and its reactive products represent useful predictors of the doses of inhaled thiol antioxidants required to ameliorate airway oxidative stress and inflammation in CF patients and provide mechanistic insight into the antioxidative/anti-inflammatory mechanisms of action of GSH and NAC when administered into the CF lung.

Myeloperoxidase-dependent oxidative metabolism of nitric oxide in the cystic fibrosis airway.

BACKGROUND: Decreased expired nitric oxide (eNO) is commonly observed in cystic fibrosis (CF) patients and is usually explained by dysregulation of NO synthase (NOS) isoforms in respiratory tract epithelium. Later stages of this disease are accompanied by intense airway infiltration of phagocytes with high NOS activity, abundant levels of the hemoprotein myeloperoxidase (MPO) and significant production of significant reactive oxygen species. METHODS: This study characterizes the contribution of the high airway levels of MPO to decreased eNO levels in adult CF patients. NO metabolites (NO(x)) and MPO levels in fresh sputum of control and adult CF patients were determined and related to measurements of eNO and to in vitro consumption of NO in CF sputum. RESULTS: Despite essentially equal levels of NO(x) in sputum, eNO was 2- to 3-fold lower in CF patients compared to healthy controls. In CF patients, eNO levels were negatively associated with sputum peroxidase activity. In vivo correlations were confirmed by ex vivo studies of NO consumption by MPO in CF sputum. Immunodepletion studies confirmed MPO as the major heme peroxidase in CF sputum contributing to the hydrogen peroxide (H(2)O(2))-dependent consumption of NO. CONCLUSIONS: In CF airways MPO acts as a phagocyte-derived NO oxidase that diminishes NO bioavailability at airway surfaces, possibly identifying this peroxidase as a potential target for therapeutic intervention.

Pathogenesis of bronchiectasis.

Cystic fibrosis (CF) typically follows a more severe clinical course than non-CF bronchiectasis. Despite this recognized difference, the underpinnings of respiratory biology support a common pathogeneses of the anatomic deformations of bronchiectasis. This article reviews the observed manifestations among the related diseases of bronchiectasis and CF and discusses some of their similarities and differences. As more details of the mechanisms of bronchiectasis are unveiled, more parallels among the seemingly disparate causes of CF and non-CF bronchiectasis are recognized. With these insights, more opportunities to halt the vicious circle have become apparent.

Addition of inhaled tobramycin to ciprofloxacin for acute exacerbations of Pseudomonas aeruginosa infection in adult bronchiectasis.

RATIONALE: Pseudomonas aeruginosa lung infection in patients with bronchiectasis, a chronic airway disease that is characterized by episodes of exacerbation, is associated with more severe disease and a higher utilization of health-care resources. Inhaled tobramycin solution reduces the number of acute exacerbations in patients with cystic fibrosis (CF)-related bronchiectasis with P aeruginosa infection but remains untested in the treatment of exacerbations in patients with non-CF bronchiectasis. OBJECTIVES: This study tested the effect of adding inhaled tobramycin solution to oral ciprofloxacin (Cip) for the treatment of acute exacerbations of non-CF bronchiectasis in patients with P aeruginosa infection. METHODS: A double-blind, randomized, active comparator, parallel-design study conducted at 17 study centers (5 in the United Kingdom, and 12 in the United States) compared 2 weeks of therapy with Cip with either an inhaled tobramycin solution or placebo in 53 adults with known P aeruginosa infection who were having acute exacerbations of bronchiectasis. MEASUREMENTS: Clinical symptoms, pulmonary function, clinical efficacy, and sputum microbiology were investigated prospectively. MAIN RESULTS: An inhaled solution of Cip with tobramycin, compared to placebo, achieved greater microbiological response but no statistically significant difference in clinical efficacy at days 14 or 21. Clinical and microbiological outcomes at the test of cure (ie, the clinical outcome assessment at day 21) were concordant when an inhaled tobramycin solution was added to therapy with Cip and compared to placebo (p = 0.01). Both subject groups had similar overall adverse event rates, but subjects receiving therapy with an inhaled tobramycin solution reported an increased frequency of wheeze (50%; placebo group, 15%). CONCLUSIONS: The addition of an inhaled tobramycin solution to therapy with oral Cip for the treatment of acute exacerbations of bronchiectasis due to P aeruginosa improved microbiological outcome and was concordant with clinical outcome; the inability to demonstrate an additional clinical benefit may have been due to emergent wheeze resulting from treatment.

Differentiation of the roles of NO from airway epithelium and inflammatory cells in ozone-induced lung inflammation.

Mice lacking inducible nitric oxide synthase (NOS2-/-) are more susceptible to ozone-induced lung inflammation and injury than their isogenic wild-type (NOS2+/+) counterparts, demonstrating an apparent protective effect for NOS2 in murine lungs. We hypothesized that nitric oxide (NO) generated from either NOS2 in the airway epithelial cells or the bone-marrow-derived inflammatory cells was responsible for the protective effect of NOS2. To test this hypothesis, we prepared chimeric mice by killing their endogenous bone marrow cells by whole body irradiation followed by bone marrow transplantation from a heterologous donor mouse. We exposed C57BL/6 (NOS2+/+), NOS2-/-, and chimeric NOS2 mice (NOS2-/+, NOS2+/-) to 1 ppm of ozone for 3 consecutive nights. NOS2-/- mice were more severely injured after exposure to ozone than C57BL/6 mice, including a more robust inflammatory cell influx (4.14 x 10(5) +/- 2.19 x 10(5) vs. 2.78 x 10(5) +/- 1.36 x 10(5) cells respectively; P = 0.036) and greater oxidation of total protein sulfhydryls (R-SH) in their blood plasma. Chimeric NOS2-/+ mice, which had bone marrow from NOS2-/- mice transplanted into C57BL/6 recipients, had a significantly greater response to ozone (increased numbers of neutrophils in lung lavage and decreased concentrations of exhaled NO) as compared to the reciprocal chimeric strain (NOS2+/-). We conclude that NOS2 has a protective effect against acute lung injury caused by ozone inhalation, which may be mediated, in part, by NO generated by NOS2 from inflammatory cells, predominantly neutrophils, recruited into the lung.