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Breath Samples (breath + sample)
Selected AbstractsA breath test to assess compliance with disulfiramADDICTION, Issue 12 2006Keron Fletcher ABSTRACT Aims To evaluate the ability of a hand-held breath analyser, the Zenalyser® (Zenics Medical), to identify alcohol-dependent patients receiving disulfiram therapy and to assess the sensitivity and specificity of the instrument at different time intervals post-disulfiram dosing. Design Breath samples were taken from two groups of alcohol-dependent patients, one group on a daily disulfiram regimen and one group receiving no disulfiram. The breath samples were analysed for the combined concentration of carbon disulphide and acetone produced from the metabolism of disulfiram. From these data, two reference ranges were prepared and used for sensitivity and specificity assessments. Setting Breath samples for the reference ranges were obtained from patients at Shelton Hospital, Shrewsbury. Breath samples used to assess the sensitivity and specificity of the instrument were obtained from patients at the Edinburgh Alcohol Problems Clinic. Participants Twenty in-patients from Shelton Hospital receiving a daily 200 mg disulfiram regimen and 20 in-patients receiving no disulfiram. At the Edinburgh Clinic, 54 patients taking a thrice-weekly disulfiram regimen and 22 patients not on disulfiram. Measurements A total of 489 breath samples from Shelton Hospital and 391 breath samples from the Edinburgh Clinic were analysed for the combined concentrations of carbon disulphide and acetone. Findings The breath analyser produced results that distinguished between the disulfiram-treated and untreated groups (P < 0.001). At 1 day post-dose, the sensitivity was 100% and the specificity was 100%. At 2 and 3 days post-dose, the sensitivities and specificities were 84.6% and 100% and 88.2% and 100%, respectively. Conclusion The breath analyser can improve the assessment of the compliance status of patients receiving a daily dose regimen of disulfiram, but is less useful for this purpose if disulfiram is taken on a thrice-weekly regimen. [source] Influence of urease activity in the intestinal tract on the results of 13C-urea breath testJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 4 2006Yoshihisa Urita Abstract Background and Aim:, A late rise in 13CO2 excretion in the 13C-urea breath test (UBT) should be found when the substrate passes rapidly through the stomach and makes contact with the colonic bacteria. The aim of this study was to evaluate the influence of intestinal urease activity on the results of the UBT. Method:, A total of 143 subjects who were diagnosed as Helicobacter pylori negative by serology, histology and rapid urease test were recruited. At the end of endoscopy, the tip of the endoscope was placed to the second part of the duodenum and 20 mL of water containing 100 mg of 13C-urea was sprayed into the duodenum. Breath samples were taken at baseline and at 5, 10, 20, 30 and 60 min after administration. Results:, Of 143 subjects, breath ,13CO2 values higher than 2.5, were detected in six (4.2%), four (2.8%) and five (3.5%) subjects at 20, 30 and 60 min, respectively. There was no subject with high ,13CO2 values at 5 and 10 min. Only one subject had an immediate rise at 60 min. Conclusion:, Variability derived from urease activity in the intestinal tract appears to be minimal up to 60 min after ingestion of the test urea. [source] Analysis of the breath hydrogen test for carbohydrate malabsorption: Validation of a pocket-sized breath test analyserJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 4 2000Ws Lee Objective: To assess the validity and clinical application of a hand-held breath hydrogen (H2) analyzer (BreatH2, Europa Scientific, Crewe, UK). Methodology: Breath samples of patients referred to the Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, South Australia, for confirmation of the diagnosis of carbohydrate malabsorption were analysed with the Quintron microlyzer (Quintron Instrument Co., Milwaukee, USA) and the BreatH2 analyser, using the Quintron microlyzer as the gold standard. Results: Twenty-nine breath H2 tests (BHT) were performed in 29 patients aged 2 months to 61 years. The sensitivity and specificity of the BreatH2 analyser in detecting a positive BHT using the Quintron microlyser as the gold standard were 0.90 and 0.95 with positive and negative predictive values of 0.90 and 0.95, respectively. There was one false positive and one false negative reading. Bland,Altman plots showed a high degree of agreement between the values obtained with two different methods. Conclusions: The diagnosis of carbohydrate malabsorption, using a portable breath H2 analyser (BreatH2), achieved an acceptable degree of sensitivity and specificity, enabling it to be used where no alternative is available. [source] Influence of Dissolved Oxygen Concentration on the Pharmacokinetics of Alcohol in HumansALCOHOLISM, Issue 5 2010In-hwan Baek Background:, Ethanol oxidation by the microsomal ethanol oxidizing system requires oxygen for alcohol metabolism, and a higher oxygen uptake increases the rate of ethanol oxidation. We investigated the effect of dissolved oxygen on the pharmacokinetics of alcohol in healthy humans (n = 49). The concentrations of dissolved oxygen were 8, 20, and 25 ppm in alcoholic drinks of 240 and 360 ml (19.5% v/v). Methods:, Blood alcohol concentrations (BACs) were determined by converting breath alcohol concentrations. Breath samples were collected every 30 min when the BAC was higher than 0.015%, 20 min at BAC ,0.015%, 10 min at BAC ,0.010%, and 5 min at BAC ,0.006%. Results:, The high dissolved oxygen groups (20, 25 ppm) descended to 0.000% and 0.050% BAC faster than the normal dissolved oxygen groups (8 ppm; p < 0.05). In analyzing pharmacokinetic parameters, AUCinf and Kel of the high oxygen groups were lower than in the normal oxygen group, while Cmax and Tmax were not significantly affected. In a Monte Carlo simulation, the lognormal distribution of mean values of AUCinf and t1/2 was expected to be reduced in the high oxygen group compared to the normal oxygen group. Conclusions:, In conclusion, elevated dissolved oxygen concentrations in alcoholic drinks accelerate the metabolism and elimination of alcohol. Thus, enhanced dissolved oxygen concentrations in alcohol may have a role to play in reducing alcohol-related side effects and accidents. [source] Volatile organic compounds in exhaled breath as a diagnostic tool for asthma in childrenCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2010J. W. Dallinga Summary Background The correct diagnosis of asthma in young children is often hard to achieve, resulting in undertreatment of asthmatic children and overtreatment in transient wheezers. Objectives To develop a new diagnostic tool that better discriminates between asthma and transient wheezing and that leads to a more accurate diagnosis and hence less undertreatment and overtreatment. A first stage in the development of such a tool is the ability to discriminate between asthmatic children and healthy controls. The integrative analysis of large numbers of volatile organic compounds (VOC) in exhaled breath has the potential to discriminate between various inflammatory conditions of the respiratory tract. Methods Breath samples were obtained and analysed for VOC by gas chromatography,mass spectrometry from asthmatic children (n=63) and healthy controls (n=57). A total of 945 determined compounds were subjected to discriminant analysis to find those that could discriminate diseased from healthy children. A set of samples from both asthmatic and healthy children was selected to construct a model that was subsequently used to predict the asthma or the healthy status of a test group. In this way, the predictive value of the model could be tested. Measurements and main results The discriminant analyses demonstrated that asthma and healthy groups are distinct from one another. A total of eight components discriminated between asthmatic and healthy children with a 92% correct classification, achieving a sensitivity of 89% and a specificity of 95%. Conclusion The results show that a limited number of VOC in exhaled air can well be used to distinguish children with asthma from healthy children. Cite this as: J. W. Dallinga, C. M. H. H. T. Robroeks, J. J. B. N. van Berkel, E. J. C. Moonen, R. W. L. Godschalk, Q. Jöbsis, E. Dompeling, E. F. M. Wouters and F. J. van Schooten, Clinical & Experimental Allergy, 2010 (40) 68,76. [source] Selected ion flow tube mass spectrometry (SIFT-MS) for on-line trace gas analysisMASS SPECTROMETRY REVIEWS, Issue 5 2005David Smith Abstract Selected ion flow tube mass spectrometry (SIFT-MS) is a new analytical technique for the real-time quantification of several trace gases simultaneously in air and breath. It relies on chemical ionization of the trace gas molecules in air/breath samples introduced into helium carrier gas using H3O+, NO+, and O precursor ions. Reactions between the precursor ions and trace gas molecules proceed for an accurately defined time, the precursor and product ions being detected and counted by a downstream mass spectrometer, thus effecting quantification. Absolute concentrations of trace gases in single breath exhalation can be determined by SIFT-MS down to ppb levels, obviating sample collection and calibration. Illustrative examples of SIFT-MS studies include (i) analysis of gases from combustion engines, animals and their waste, and food; (ii) breath and urinary headspace studies of metabolites, ethanol metabolism, elevated acetone during ovulation, and exogenous compounds; and (iii) urinary infection and the presence of tumors, the influence of dialysis on breath ammonia, acetone, and isoprene, and acetaldehyde released by cancer cells in vitro. Flowing afterglow mass spectrometry (FA-MS) is briefly described, which allows on-line quantification of deuterium in breath water vapor. © 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:661,700, 2005 [source] A breath test to assess compliance with disulfiramADDICTION, Issue 12 2006Keron Fletcher ABSTRACT Aims To evaluate the ability of a hand-held breath analyser, the Zenalyser® (Zenics Medical), to identify alcohol-dependent patients receiving disulfiram therapy and to assess the sensitivity and specificity of the instrument at different time intervals post-disulfiram dosing. Design Breath samples were taken from two groups of alcohol-dependent patients, one group on a daily disulfiram regimen and one group receiving no disulfiram. The breath samples were analysed for the combined concentration of carbon disulphide and acetone produced from the metabolism of disulfiram. From these data, two reference ranges were prepared and used for sensitivity and specificity assessments. Setting Breath samples for the reference ranges were obtained from patients at Shelton Hospital, Shrewsbury. Breath samples used to assess the sensitivity and specificity of the instrument were obtained from patients at the Edinburgh Alcohol Problems Clinic. Participants Twenty in-patients from Shelton Hospital receiving a daily 200 mg disulfiram regimen and 20 in-patients receiving no disulfiram. At the Edinburgh Clinic, 54 patients taking a thrice-weekly disulfiram regimen and 22 patients not on disulfiram. Measurements A total of 489 breath samples from Shelton Hospital and 391 breath samples from the Edinburgh Clinic were analysed for the combined concentrations of carbon disulphide and acetone. Findings The breath analyser produced results that distinguished between the disulfiram-treated and untreated groups (P < 0.001). At 1 day post-dose, the sensitivity was 100% and the specificity was 100%. At 2 and 3 days post-dose, the sensitivities and specificities were 84.6% and 100% and 88.2% and 100%, respectively. Conclusion The breath analyser can improve the assessment of the compliance status of patients receiving a daily dose regimen of disulfiram, but is less useful for this purpose if disulfiram is taken on a thrice-weekly regimen. [source] Breath gas aldehydes as biomarkers of lung cancerINTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Patricia Fuchs Abstract There is experimental evidence that volatile substances in human breath can reflect presence of neoplasma. Volatile aldehydes were determined in exhaled breath of 12 lung cancer patients, 12 smokers and 12 healthy volunteers. Alveolar breath samples were collected under control of expired CO2. Reactive aldehydes were transformed into stable oximes by means of on-fiber-derivatization (SPME-OFD). Aldehyde concentrations in the ppt and ppb level were determined by means of gas chromatography-mass spectrometry (GC-MS). Exhaled concentrations were corrected for inspired values. Exhaled C1,C10 aldehydes could be detected in all healthy volunteers, smokers and lung cancer patients. Concentrations ranged from 7 pmol/l (161 pptV) for butanal to 71 nmol/l (1,582 ppbV) for formaldehyde. Highest inspired concentrations were found for formaldehyde and acetaldehyde (0,55 nmol/l and 0,13 nmol/l, respectively). Acetaldehyde, propanal, butanal, heptanal and decanal concentrations showed no significant differences for cancer patients, smokers and healthy volunteers. Exhaled pentanal, hexanal, octanal and nonanal concentrations were significantly higher in lung cancer patients than in smokers and healthy controls (ppentanal = 0.001; phexanal = 0.006; poctanal = 0.014; pnonanal = 0.025). Sensitivity and specificity of this method were comparable to the diagnostic certitude of conventional serum markers and CT imaging. Lung cancer patients could be identified by means of exhaled pentanal, hexanal, octanal and nonanal concentrations. Exhaled aldehydes reflect aspects of oxidative stress and tumor-specific tissue composition and metabolism. Noninvasive recognition of lung malignancies may be realized if analytical skills, biochemical knowledge and medical expertise are combined into a joint effort. [source] Determination of the optimal cut-off value for the [13C]-urea breath test based on a Helicobacter pylori -specific polymerase chain reaction assayJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2 2000Haruhiko Yoshida Abstract Background: This study was conducted to determine the optimal cut-off value and breath sample collection time for the [13C]-urea breath test based on the assessment of Helicobacter pylori status with a gastric juice-based polymerase chain reaction (PCR) assay. Methods and Results: A total of 104 patients took 100 mg [13C]-urea orally and breath samples were collected at 5, 10, 20, 30 and 60 min. The increment of 13CO2: 12CO2 ratio from the baseline (,13C) was measured using a laser spectroanalyser. The PCR assay was positive in 63 and negative in 41 patients. The optimal cut-off value of ,13C was calculated for each sample collection time so that the distance from the geometric mean value among Helicobacter pylori -positive patients and that from the arithmetic mean value among negative patients were simultaneously maximized. The cut-off value of 2.7, at 20 min had the longest distance, being separated by 3.16 SD from the two mean values. Using this cut-off value, the urea breath test showed 100% specificity and 98% sensitivity for the diagnosis of Helicobacter pylori infection. [source] A MOUSE MODEL FOR ASSESSING THE IMPACT OF INGESTED NUTRIENTS ON GASTRIC EMPTYING RATECLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 1-2 2007Erin L Symonds SUMMARY 1The nutrient content of meals can affect the rate of gastric emptying. The aim of the present study was to assess whether the gastric emptying breath test could detect nutrient-induced delays in gastric emptying. 2Following ingestion of a non-nutrient, carbohydrate- or lipid-containing liquid, mice were placed into chambers and breath samples were collected at intervals. Analysis of the rate of 13CO2 excretion allowed the calculation of gastric half-excretion time. 3Gastric half-excretion time was significantly delayed by the incorporation of carbohydrate or lipid into the test liquid. 4The present study has shown that the breath test is sensitive enough to detect changes induced by altering the nutrient and caloric content of test meals. [source] | ||||||||||