Long-term continuous positive airway pressure therapy normalizes high exhaled nitric oxide levels in obstructive sleep apnea.

Study Objectives: Upper airway inflammation and oxidative stress have been implicated in the pathogenesis of obstructive sleep apnea (OSA) and may be linked to cardiovascular consequences. We prospectively examined fraction of exhaled nitric oxide (FENO), a surrogate marker of upper airway inflammation using a portable nitric oxide analyzer (NIOX MINO).

Design: In consecutive adult nonsmokers with suspected OSA, FENO was measured immediately before and after polysomnographic studies, and within 1-3 months following continuous positive airway pressure (CPAP) therapy.

Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension.

Background: Reduced gas transfer in patients with pulmonary arterial hypertension (PAH) is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange.

Methods: We tested this hypothesis by determination of lung diffusing capacity (DL) and its components, the alveolar capillary membrane diffusing capacity (D(m)) and lung capillary blood volume (V(c)) in 28 individuals with PAH in comparison to 41 healthy individuals, and in 19 PAH patients over time. Using single breath simultaneous measure of diffusion of carbon monoxide (DL(CO)) and nitric oxide (DL(NO)), DL and D(m) were respectively determined, and V(c) calculated.

Nitric oxide in adaptation to altitude.

This review summarizes published information on the levels of nitric oxide gas (NO) in the lungs and NO-derived liquid-phase molecules in the acclimatization of visitors newly arrived at altitudes of 2500 m or more and adaptation of populations whose ancestors arrived thousands of years ago. Studies of acutely exposed visitors to high altitude focus on the first 24-48 h with just a few extending to days or weeks. Among healthy visitors, NO levels in the lung, plasma, and/or red blood cells fell within 2h, but then returned toward baseline or slightly higher by 48 h and increased above baseline by 5 days.

Effects of the menstrual cycle on lung function variables in women with asthma.

Rationale: Angiogenesis is a defining pathologic feature of airway remodeling and contributes to asthma severity. Women experience changes in asthma control over the menstrual cycle, a time when vessels routinely form and regress under the control of angiogenic factors. One vital function modulated over the menstrual cycle in healthy women is gas transfer, and this has been related to angiogenesis and cyclic expansion of the pulmonary vascular bed.

A technical report on exhaled nitric oxide measurement: asthma monitoring in athletes.

Exhaled NO (FE(NO)) measurements have been utilized as a marker to diagnose asthma as well as a non-invasive tool for monitoring airway inflammation and the response to anti-inflammatory medications. One area where this non-invasive monitoring may be helpful is for asthmatic athletes as they train for competitive events. We hypothesized that in the course of training an asthmatic individual may experience worsening of lung inflammation reflected in FE(NO) levels that may be too subtle to detect by conventional methods like spirometry.

Pulmonary gas transfer related to markers of angiogenesis during the menstrual cycle.

Gas transfer in the female lung varies over the menstrual cycle in parallel with the cyclic angiogenesis that occurs in the uterine endometrium. Given that vessels form and regress in the uterus under the control of hormones, angiogenic factors, and proangiogenic circulating bone marrow-derived progenitor cells, we tested the possibility that variation in pulmonary gas transfer over the menstrual cycle is related to a systemic cyclic proangiogenic state that influences lung vascularity. Women were evaluated over the menstrual cycle with weekly measures of lung diffusing capacity and its components, the pulmonary vascular capillary bed and membrane diffusing capacity, and their relation to circulating CD34(+)CD133(+) progenitor cells, hemoglobin, factors affecting hemoglobin binding affinity, and proangiogenic factors.

Diagnosis of lung cancer by the analysis of exhaled breath with a colorimetric sensor array.

Background: The pattern of volatile organic compounds (VOCs) in the exhaled breath of patients with lung cancer may be unique. New sensor systems that detect patterns of VOCs have been developed. One of these sensor systems, a colorimetric sensor array, has 36 spots composed of different chemically sensitive compounds impregnated on a disposable cartridge.

Effect of dexamethasone on atrial fibrillation after cardiac surgery: prospective, randomized, double-blind, placebo-controlled trial.

Objective: The purpose of this study was to assess the effect of preoperative dexamethasone (DEX) on the occurrence of postoperative atrial fibrillation (AF).

Design: Prospective, randomized, double-blind, placebo-controlled clinical trial.

Setting: Tertiary referral center.

Nitric oxide and cardiopulmonary hemodynamics in Tibetan highlanders.

When O2 availability is reduced unavoidably, as it is at high altitude, a potential mechanism to improve O2 delivery to tissues is an increase in blood flow. Nitric oxide (NO) regulates blood vessel diameter and can influence blood flow. This field study of intrapopulation variation at high altitude tested the hypothesis that the level of exhaled NO (a summary measure of pulmonary synthesis, consumption, and transfer from cells in the airway) is directly proportional to pulmonary, and thus systemic, blood flow.

Detection of lung cancer by sensor array analyses of exhaled breath.

Rationale: Electronic noses are successfully used in commercial applications, including detection and analysis of volatile organic compounds in the food industry.

Objectives: We hypothesized that the electronic nose could identify and discriminate between lung diseases, especially bronchogenic carcinoma.

Methods: In a discovery and training phase, exhaled breath of 14 individuals with bronchogenic carcinoma and 45 healthy control subjects or control subjects without cancer was analyzed.

Nitric oxide and pulmonary arterial pressures in pulmonary hypertension.

Decreased production of vasodilator substances such as nitric oxide (NO) has been proposed as important in development of pulmonary arterial hypertension (PAH). We hypothesize that NO measured over time serves as a non invasive marker of severity of PAH and response to therapy. We prospectively and serially measured exhaled NO and carbon monoxide (CO), a vasodilator and anti-inflammatory product of heme oxygenases, in 17 PAH patients in conjunction with hemodynamic parameters over 2 years.

Dysregulation of endogenous carbon monoxide and nitric oxide production in patients with advanced ischemic or nonischemic cardiomyopathy.

Carbon monoxide (CO) and nitric oxide (NO) are endogenous vasoregulatory molecules whose role in heart failure is not fully known. Exhaled CO and NO measurement provide novel noninvasive assessment of their endogenous production. We compared exhaled CO and NO in 24 patients with advanced ischemic and nonischemic cardiomyopathy and in 13 control subjects without known cardiac disease at rest and at 1 and 5 minutes after exercise testing.

Low levels of nitric oxide and carbon monoxide in alpha 1-antitrypsin deficiency.

Quantitations of exhaled nitric oxide (NO) and carbon monoxide (CO) have been proposed as noninvasive markers of airway inflammation. We hypothesized that exhaled CO is increased in individuals with alpha(1)-antitrypsin (AT) deficiency, who have lung inflammation and injury related to oxidative and proteolytic processes. Nineteen individuals with alpha(1)-AT deficiency, 22 healthy controls, and 12 patients with non-alpha(1)-AT-deficient chronic obstructive pulmonary disease (COPD) had NO, CO, CO(2), and O(2) measured in exhaled breath.