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At least 595 records · Page 33Linked to original sources
PubMed2006

Breath condenser coatings affect measurement of biomarkers in exhaled breath condensate.

Exhaled breath condensate collection is not yet standardised and biomarker measurements are often close to lower detection limits. In the current study, it was hypothesised that adhesive properties of different condenser coatings interfere with measurements of eicosanoids and proteins in breath condensate. In vitro, condensate was derived from a collection model using two test solutions (8-isoprostane and albumin) and five condenser coatings (silicone, glass, aluminium, polypropylene and Teflon). In vivo, condensate was collected using these five coatings and the EcoScreen condenser to measure 8-isoprostane, and three coatings (silicone, glass, EcoScreen) to measure albumin. In vitro, silicone and glass coatings had significantly higher albumin recovery compared with the other coatings. A similar trend was observed for 8-isoprostane recovery. In vivo, median (interquartile range) 8-isoprostane concentrations were significantly higher using silicone (9.2 (18.8) pg.mL(-1)) or glass (3.0 (4.5) pg.mL(-1)) coating, compared with aluminium (0.5 (2.4) pg.mL(-1)), polypropylene (0.5 (0.5) pg.mL(-1)), Teflon (0.5 (0.0) pg.mL(-1)), and EcoScreen (0.5 (2.0) pg.mL(-1)). Albumin in vivo was mainly detectable using glass coating. In conclusion, a condenser with silicone or glass coating is more efficient for measurement of 8-isoprostane or albumin in exhaled breath condensate, than EcoScreen, aluminium, polypropylene or Teflon. Guidelines for exhaled breath condensate standardisation should include the most valid condenser coating to measure a specific biomarker.

Adolescent↗
PubMed1998

Bronchial obstruction and exhaled nitric oxide response during exercise in cold air.

This study examines whether exhausting exercise in cold air induces bronchial obstruction and changes in exhaled [NO] and in exhaled NO output (V'NO). Thus, eight well-trained males performed two incremental exercise tests until exhaustion, followed by 5 min of recovery in temperate (22 degrees C) and cold (-10 degrees C) environments, at random. At -10 degrees C, they were dressed in warm clothes. Ventilation (V'E), oxygen consumption (V'O2), carbon dioxide production, cardiac frequency (fC), and [NO] and V'NO were measured continuously. Before and after each test, the subjects' maximal expiratory flow-volume curves and peak expiratory flow, forced expiratory volume in one second (FEV1) and forced expiratory flow at 25 (FEF25), 50 (FEF50) and 75% (FEF75) of forced vital capacity were determined. At -10 degrees C, significant decreases in FEV1 and FEF75 were observed after exercise. At rest and at the same submaximal intensity, V'O2, V'E and fC did not differ significantly. At rest and up to approximately 50% peak V'O2, [NO] and V'NO values were lower at -10 degrees C than at 22 degrees C. Thereafter, and during recovery, the V'NO response became similar at both -10 and 22 degrees C. This study confirms that considerable hyperpnoea in cold air causes a detectable airway obstruction. This airway cooling also induces an initial decrease in the exhaled NO response. Since endogenous NO-production is involved in bronchial dilation, it cannot be excluded that this lack of production may favour the appearance of airway obstruction.

Adult↗
PubMed2006

Method optimization and validation for the simultaneous determination of arachidonic acid metabolites in exhaled breath condensate by liquid chromatography-electrospray ionization tandem mass spectrometry.

BACKGROUND: Determinations of inflammatory markers in exhaled breath condensate were used to assess airway inflammation. The most applied method for this kind of determination is enzyme immunoassay. For research purposes to find new or to relate concrete biomarkers to different pulmonary diseases, a simultaneous determination of different inflammatory markers would be advantageous. METHODS: We developed an analytical method with on-line clean up and enrichment steps to determine 12 different inflammatory markers in exhaled breath condensate. A specific detection method ensures the unequivocally determination of each analyte at the same run. The method was optimized and validated to achieve a low limit of quantification up to 10 pg/mL each analyte. The precision of the method ranged between 4 and 16%. CONCLUSION: The presented method should serve as an easy and fast tool to assess the utility of inflammatory markers in exhaled breath condensate to different pulmonary diseases and for several related disciplines in medicine.

Journal Article↗
PubMed1989

Mechanics of the respiratory system during passive exhalation in preterm lambs.

Previous studies have shown large inhomogeneities in the distributions of ventilation and perfusion of newborn infants with hyaline membrane disease. The purpose of this study was to show that measurements of lung mechanics also show evidence of lung inhomogeneities and that a multiple compartment analysis of mechanics gives a more accurate representation of passive exhalation flow and volume than single valued mechanics. We studied 10 sedated preterm lambs (130 d gestation) weighing 2.2 +/- 0.3 kg at 4 h postnatal age. Passive exhalation lung mechanics of the respiratory system were measured by obstructing gas flow near end inhalation then, after pressures within the lung reached equilibrium, allowing the animals to exhale to the atmosphere. Airway pressure and flow signals were monitored by a computer then analyzed using single and multiple compartment analyses. Single compartment analysis of time constant (tau) in s, respiratory system resistance (R) in cm H2O/L/s and quasistatic compliance (C) in mL/cm H2O yielded tau = 0.16 +/- 0.07, R = 92 +/- 17, and C = 1.8 +/- 1.1 (mean +/- SD). Multiple compartment analysis yielded "fast compartment" tau 1 = 0.10 +/- 0.04, R1 = 90 +/- 28, and C1 = 1.1 +/- 0.5 and "slow compartment" tau 2 = 0.25 +/- 0.12, R2 = 503 +/- 288, and C2 = 0.7 +/- 0.6. All of the animals studied exhibited nonlinearity in their flow-volume plots. Calculated flow-volume plots were much more accurately portrayed by the two-compartment analysis than by single valued mechanics. Multiple compartment analysis of lung mechanics may provide useful insight into the pathophysiology of the preterm lab with hyaline membrane disease.

Animals↗
PubMed1993

Reperfusion injury and exhaled hydrogen peroxide.

Reactive oxygen species have been implicated in the pathophysiology of lung injury associated with the sequence of ischemia-reperfusion. To study this, we measured the exhaled breath hydrogen peroxide concentration [H2O2] in human and canine models of reperfusion lung injury. Our models were patients subjected to cardiopulmonary bypass (CPB) (Group 1), patients undergoing pulmonary thromboendarterectomy (Group 2), canine single lung transplant (Group 3), and patients subjected to peripheral ischemia resulting from aortic cross-clamping or tourniquet application (Group 4). In addition, we studied two groups with severe lung injury as positive controls. These consisted of hydrochloric acid (HCl)-induced canine lung injury (Group 5) and patients with adult respiratory distress syndrome (Group 6). The exhaled H2O2 was collected by using a -2 degrees C glass coil and assayed by a spectrophotometric method. In Group 1 samples were collected before and immediately after CPB. Group 2 samples were obtained before CPB, immediately after CPB, 3 h later, and daily until extubation. Samples in Group 3 were collected before lung transplant, and hourly for 3 h beginning immediately afterward. Group 4 samples were collected at the onset of reperfusion. Samples from Group 5 were collected before HCl and after HCl injury, at 0.5-1.5 and 2-3 h. Group 6 samples were collected when criteria for adult respiratory distress syndrome were met. Groups 1, 3, and 4 exhibited no significant increases in exhaled [H2O2] compared to control values. Group 2 had significantly increased [H2O2] (5.59 +/- 3.07 x 10(-7) mol/L, P = 0.028) on postoperative Day 2, but there was no correlation of [H2O2] with physiologic indicators of lung injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Sevoflurane in exhaled air of operating room personnel.

UNLABELLED: Evidence on potential health hazards arising from exposure to volatile anesthetics remains controversial. Exposure may, in principle, be supervised by monitoring of ambient air or, alternatively, in vivo. We used the Proton Transfer Reaction-Mass Spectrometry to screen the breath of 40 operating room staff members before operating room duty, 0, 1, 2, and 3 h after duty, and before commencing duty on the consecutive day, and control persons. Staff members exhibited significantly increased sevoflurane levels in exhaled air after duty, with a mean of 0.80 parts per billion as compared with baseline values of 0.26 parts per billion (P < 0.05). Analysis of variance with adjustment for within correlation (repeated measurements) showed a statistically significant time-effect (P < 0.001). We conclude that (a) Proton Transfer Reaction-Mass Spectrometry biomonitoring of exhaled sevoflurane can serve as a simple and rapid method to determine volatile anesthetic excretion after occupational exposure, and (b) significant concentrations of sevoflurane may be continuously present in persons exposed to sevoflurane on a daily basis. IMPLICATIONS: The present study depicts the profile of volatile anesthetics, isoflurane and sevoflurane, in exhaled air of ambulatory patients. Biomonitoring of expired anesthetic concentrations is a noninvasive and rapid method to determine volatile anesthetic excretion.

Adult↗
PubMed2004

Exhaled breath condensate as a suitable matrix to assess lung dose and effects in workers exposed to cobalt and tungsten.

The aim of the present study was to investigate whether exhaled breath condensate (EBC), a fluid formed by cooling exhaled air, can be used as a suitable matrix to assess target tissue dose and effects of inhaled cobalt and tungsten, using EBC malondialdehyde (MDA) as a biomarker of pulmonary oxidative stress. Thirty-three workers exposed to Co and W in workshops producing either diamond tools or hard-metal mechanical parts participated in this study. Two EBC and urinary samples were collected: one before and one at the end of the work shift. Controls were selected among nonexposed workers. Co, W, and MDA in EBC were analyzed with analytical methods based on mass spectrometric reference techniques. In the EBC from controls, Co was detectable at ultratrace levels, whereas W was undetectable. In exposed workers, EBC Co ranged from a few to several hundred nanomoles per liter. Corresponding W levels ranged from undetectable to several tens of nanomoles per liter. A parallel trend was observed for much higher urinary levels. Both Co and W in biological media were higher at the end of the work shift in comparison with preexposure values. In EBC, MDA levels were increased depending on Co concentration and were enhanced by coexposure to W. Such a correlation between EBC MDA and both Co and W levels was not observed with urinary concentration of either element. These results suggest the potential usefulness of EBC to complete and integrate biomonitoring and health surveillance procedures among workers exposed to mixtures of transition elements and hard metals. Key words: cobalt, exhaled breath condensate, hard metals, lung, malondialdehyde, oxidative stress, tungsten.

Adult↗
PubMed1998

Exhaled breath condensate isoprostanes are elevated in patients with acute lung injury or ARDS.

BACKGROUND: Oxidant stress is a purported mechanism of tissue damage in patients with ARDS and acute lung injury (ALI). Isoprostanes, prostanoid compounds primarily formed nonenzymatically via lipid peroxidation, are precise markers of in vivo oxidant stress. Plasma levels of metabolites of 8-iso-prostaglandin-F2alpha (8-iso-PGF2alpha) correlate with outcome in patients with ARDS. OBJECTIVE: To examine exhaled breath condensate levels of 8-iso-PGF2alpha as a noninvasive quantification of pulmonary oxidant stress in patients with, or at risk for, ARDS/ALI. METHODS: Breath condensate was collected from 22 patients with, or at risk for, ARDS/ALI by placing Tygon tubing submerged in an ice bath in line with the expiratory limb of the ventilator circuit. Ten patients without lung disease, who were intubated while undergoing minor surgical procedures, served as control subjects. Between 1 and 3 mL of condensate was collected over a 30- to 60-min period, then immediately frozen and stored at -70 degrees C until analysis. The 8-iso-PGF2alpha was purified and derivatized, then quantified by stable isotope dilution in conjunction with gas chromatography/mass spectrometry. RESULTS: The mean level of exhaled 8-iso-PGF2alpha in the patients with ALI/ARDS, 87+/-28 pg/mL, was significantly higher than the mean in the normal group, 7+/-4 pg/mL (p = 0.007). The 8-iso-PGF2alpha levels were greater than two standard deviations above the mean of the normal group in 12 of 22 patients with or at risk for ARDS/ALI. CONCLUSIONS: These results provide further evidence that lipid peroxidation does occur in patients with ARDS/ALI. The measurement of exhaled isoprostanes provides a novel, noninvasive method to quantify oxidant stress in such patients.

Breath Tests↗
PubMed2005

Use of exhaled breath condensate in the study of airway inflammation after hypertonic saline solution challenge.

STUDY OBJECTIVES: Hypertonic saline solution inhalation is suspected to produce airway inflammation. DESIGN: The aim of this study was to verify this hypothesis by measuring inflammatory markers in exhaled breath condensate (EBC) collected before and after sputum induction with hypertonic and isotonic saline solution. PATIENTS AND METHODS: We enrolled 10 patients with asthma, 10 patients with COPD, and 7 healthy subjects with no history of lung disease. Levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha were measured in EBC by a specific enzyme immunoassay kit. Exhaled pH was measured after deaeration/decarbonation by bubbling with argon (350 mL/min) for 10 min by means of a pH meter. MEASUREMENTS AND RESULTS: Exhaled IL-6 and TNF-alpha concentrations were greater and pH was decreased compared to baseline after hypertonic saline solution inhalation in each group of subjects studied. No changes were observed following isotonic saline solution inhalation. Concentrations of IL-6, TNF-alpha, and pH in EBC correlated. CONCLUSIONS: These findings suggest that hypertonic saline solution inhalation could cause a low-grade inflammation in airways, and levels of inflammatory markers such as IL-6, TNF-alpha, and pH in EBC may be a useful noninvasive way to assess and monitor airway inflammation.

Aged↗
PubMed1996

Lack of inhibitory effect of dexamethasone on exhalation of nitric oxide by healthy humans.

Nitric oxide (NO) is present in the breath exhaled from healthy humans. The location and subtype of the NO synthase responsible for the expired NO are unknown. As dexamethasone inhibits the induction of NO synthase, we evaluated the effect of administering dexamethasone (4 mg/day for 2 days) on the amount of NO exhaled by eight healthy men. The amount of NO showed a significant linear correlation with the duration of exhalation, allowing the rate of NO release to be calculated. The rate of NO release was 0.047 +/- 0.023 nmol/s before drug administration. There was no significant change in the release rate at the end of the 2-day administration of drug or at 5 days after cessation. Serum concentrations of interferon-gamma and interleukin-1 beta were unaffected by the administration of dexamethasone. These results suggest that the NO released from the human airway under normal conditions is not generated by the action of inducible NO synthase.

Adult↗
PubMed2000

Effects of moderate altitude on exhaled nitric oxide, erythrocytes lipid peroxidation and superoxide dismutase levels.

The purpose of this study was to investigate the effects of staying at a moderate altitude (2,300 m, 7 d) on the levels of plasma nitrite, exhaled nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD). Measurements were obtained from 9 female (mean age 18.3 +/- 2) and 9 male (mean age 19.3 +/- 3.7) cross-country volunteer skiers: before, during (1st day, 7th day) and after staying at a moderate altitude. Exhaled nitric oxide levels were measured only before and after staying at the altitude. Nitrite levels increased throughout the stay at the altitude, while MDA levels decreased. In parallel with the nitrite levels, SOD activities were also found to have increased. Exhaled NO values were decreased after the stay at the moderate altitude. These results show that altitude hypoxia causes decreased in NO levels in the lung but increased systemic NO levels in the blood due to inhibition of erythrocyte lipid peroxidation.

Administration, Inhalation↗
PubMed1998

Respiratory tract inflammation in swine confinement workers studied using induced sputum and exhaled nitric oxide.

OBJECTIVE: To further define the asthma-like syndrome seen in swine confinement workers. DESIGN: A cross-sectional study was performed at a swine confinement facility in rural Nebraska and at the University of Nebraska Medical Center, Omaha, Nebraska. PARTICIPANTS: 24 swine confinement workers and 14 urban normal control subjects. All subjects completed a questionnaire concerning respiratory complaints. We performed hypertonic saline challenges on the swine confinement workers and control subjects in order to induce expectoration of sputum. Cell counts and cell differentials were determined in the induced sputum samples. Nasal, mean, and peak exhaled nitric oxide was measured in both groups. Spirometry was also done. RESULTS: Swine confinement workers were significantly more likely to report wheezing, cough, and sinusitis symptoms than controls (p = .003). Macrophages were significantly elevated in the induced sputum samples of the swine confinement workers vs the control subjects (0.59 macrophages/mL +/- 0.1 SEM vs 0.36 +/- .16; p = .006), while there was no difference in numbers of neutrophils. No eosinophils were observed. A small elevation in mean exhaled nitric oxide was seen in the swine confinement workers compared to normal controls (11.7 ppb +/- 0.6 SEM vs 10.2 +/- 1.6; p = 0.023). Spirometry values did not differ statistically between swine confinement workers and the control group. CONCLUSIONS: Swine confinement workers have signs and symptoms of lower respiratory tract inflammation when studied using induced sputum and exhaled nitric oxide. Findings in the swine confinement workers differ from those in asthmatics and chronic bronchitis.

Adult↗
PubMed1999

Failure of exhalation during ventilation with the Dräger Oxylog 2000 ventilator.

We describe three cases in which there was failure of exhalation during mechanical ventilation with the Dräger Oxylog 2000 ventilator. Two potential mechanisms for this failure were identified, and were then experimentally reproduced on a test lung. First, a manufacturing fault in the silicone diaphragm in the ventilation valve was discovered. When a small hole in the diaphragm was incompletely perforated, a possible flap valve was formed, limiting exhalation. Second, failure of the one-way rubber disc valve to seat properly in its housing also prevented exhalation. These two previously unreported modes of ventilator failure have been identified. Careful checking of the ventilator circuit before each use is required.

Aged↗
PubMedDate not supplied

The origin of intermittent exhalation (A! Ha! Ha!) peculiar to human laugh.

Since Darwin (1872), the origin of the laugh with an intermittent exhalation "A! Ha! Ha!" which is peculiar to human, has been a great question. The author found out that this laugh is caused by the three sets of emotion. Firstly, light surprise or discovery. The ability to estimate "light" is absolutely important, because the amount of the first exhalation "A!" caused by the stimulation is decided by the amount of "surprise" felt by the subject. The ability to estimate the amount of "surprise" to be "light", makes the partial exhalation "A!". Secondly, consciousness of this harmlessness or delight, and thirdly, the following expectation of some safe circumstances. The author proved this theory by electromyography (EMG), photoplethysmography and galvanic skin reaction (GSR). The similarity between the facial EMG distribution pattern of "the beginning of laugh" and "the light surprise" was proved by electromyography about many facial muscles, with special fine electrode which did not disturb any natural facial expression of the subjects. Plethysmography and GSR proved light sympathetic tension and following relaxation when laughing. The author also suggests relationships between human laugh and human history such as the origin of clothing, language, and use of fire, which are specific in human.

Animals↗
PubMed1999

Exhaled carbon monoxide concentration increases after exercise in children with cystic fibrosis.

Oxidative stress and hypoxia, which may occur in cystic fibrosis patients (CF) at rest and may be worsened by exercise, induce the expression of heme oxygenase (HO)-1, resulting in increased carbon monoxide (CO) formation. We tested that exhaled CO level (eCO) was higher in CF patients than in healthy subjects, and that exercise increased CO production. Exhaled CO was measured electrochemically in 15 CF patients and 15 control subjects at rest (T0), immediately (T1) and 60 minutes after a symptom-limited incremental bicycle exercise test (T60). Arterial oxygen saturation (TcO2) was monitored transcutaneously. Data are given as mean+/-SEM. Baseline eCO was 1.90+/-0.26 ppm in the control and 1.93+/-0.27 ppm in the CF group. In both groups eCO was lower at T1 than at rest. In the control group eCO was also low at T60, but in the CF group it was increased compared to baseline level at this timepoint. Exercise caused oxyhemoglobin desaturation in CF patients which was related to the increase in eCO measured at T60 (r=0.67, p<0.01). Our findings suggest that exercise modulates the level of exhaled CO partly by worsening oxygenation in CF patients.

Adolescent↗
PubMed2000

[Exhaled nitric oxide].

We introduce the standard method of measurement of nitric oxide recommended by American thoracic society in 1999 and report the results of exhaled NO and nasal NO in patients with obstructive sleep apnea syndrome(OSAS). Our data showed lower exhaled NO output in the patients with OSAS than that of normal volunteers(NV) and that of patients with simple obesity(SO). On the other hand, nasal NO in the OSAS patients is higher than that of NV and that of SO patients. Also, there were significant relationships between apnea index and exhaled NO and between desaturation during sleep and nasal NO. These findings suggested that NO from lower and upper airway will be a non-invasive maker of sleep disordered breathing in future.

Breath Tests↗
PubMed2000

Noninvasive assessment of airway inflammation in children: induced sputum, exhaled nitric oxide, and breath condensate.

Noninvasive markers of airway inflammation are needed for use in research and clinical practice in childhood asthma. Induced sputum and exhaled nitric oxide are well established as direct markers of inflammation for use in asthma research. Sputum can be induced from children of >6 yrs using inhalation of hypertonic saline, and, if appropriate, can be combined with an assessment of airway responsiveness to hypertonic saline. The success rate of sputum induction in children is 68-100%. Most studies have processed sputum using the plug selection method, and show that the dominant cell in sputum from normal children is the macrophage, and that the upper normal limit for sputum eosinophils in children is 2.5%. The inflammatory response in childhood asthma is characterized by elevated numbers of sputum eosinophils, and eosinophil cationic protein concentration, as well as increased nitric oxide and hydrogen peroxide levels in exhaled breath. Sputum eosinophils correlate with objective markers of disease severity in steroid-naive children with asthma, and in severe asthma. Inflammatory marker levels are lower in children using glucocorticosteroids. Induced sputum and exhaled gases are important markers of inflammation in childhood asthma. The clinical utility of these markers warrants further study.

Breath Tests↗