Science.gov

Sample records for 13co2 breath test

  1. Adaptation of the NDIR technology to 13CO2 breath tests under increased inspiratory O2 concentrations.

    PubMed

    Vogt, Josef A; Wachter, Ulrich; Mehring, Jürgen; Radermacher, Peter; Georgieff, Michael; Fischer, Heinz; Hölscher, Uvo; Moede, Michael; Fabinski, Walter

    2009-07-01

    Nondispersive infrared spectroscopy (NDIR) allows the continuous analysis of respiratory gases. Due to its high selectivity, simple and robust setup, and small footprint, it is also used to support (13)CO(2) breath tests to assess bacterial growth in the stomach, gut, or liver function. CO(2) NDIR signals, however, are biased by oxygen in the gas matrix. This complicates NDIR-based breath tests, if the inspired oxygen concentration has to be adjusted to the subject's requirements, or hyperoxia-induced effects were studied. To avoid the oxygen-induced bias, a "dilution" approach was developed: expired gas is mixed with N(2) to lower the oxygen content down to the usual range of 15-20%. Accuracy and precision were tested using synthetic gas mixtures with increasing (13)CO(2)-to-(12)CO(2) ratios ((13)CO(2)/(12)CO(2)), either based on synthetic air with approximately 20% volume O(2) or on pure O(2). For samples with delta(13)C values smaller than 300 (or (13)CO(2)/(12)CO(2) smaller than 0.003), the dilution does not significantly increase the bias in the (13)CO(2)/(12)CO(2) determination, and the within-run imprecision is smaller than 1 delta(13)C. The practical use of this approach was validated in a pig study using a sepsis model reflecting a clinical situation that requires an increased oxygen concentration for respiration. The N(2) dilution eliminated the high bias in NDIR measurement, thus allowing the determination of the impact of oxygenation on glucose oxidation in patients ventilated with increased oxygen.

  2. 13CO2/12CO2 isotope ratio analysis in human breath using a 2 μm diode laser

    NASA Astrophysics Data System (ADS)

    Sun, Mingguo; Cao, Zhensong; Liu, Kun; Wang, Guishi; Tan, Tu; Gao, Xiaoming; Chen, Weidong; Yinbo, Huang; Ruizhong, Rao

    2015-04-01

    The bacterium H. pylori is believed to cause peptic ulcer. H. pylori infection in the human stomach can be diagnosed through a CO2 isotope ratio measure in exhaled breath. A laser spectrometer based on a distributed-feedback semiconductor diode laser at 2 μm is developed to measure the changes of 13CO2/12CO2 isotope ratio in exhaled breath sample with the CO2 concentration of ~4%. It is characterized by a simplified optical layout, in which a single detector and associated electronics are used to probe CO2 spectrum. A new type multi-passes cell with 12 cm long base length , 29 m optical path length in total and 280 cm3 volume is used in this work. The temperature and pressure are well controlled at 301.15 K and 6.66 kPa with fluctuation amplitude of 25 mK and 6.7 Pa, respectively. The best 13δ precision of 0.06o was achieved by using wavelet denoising and Kalman filter. The application of denoising and Kalman filter not only improved the signal to noise ratio, but also shorten the system response time.

  3. Towards an inhalative 13C breath test method.

    PubMed

    Krumbiegel, P; Rolle-Kampczyk, U; Liebergeld, P; Herbarth, O; Köbrich, R

    2002-06-01

    Customary 13CO2 breath tests--and also 15N urine tests--always start with an oral administration of a test substrate. The test person swallows a stable isotope labelled diagnostic agent. This technique has been used to study several pathophysiological changes in gastrointestinal organs. However, to study pathophysiological changes of the bronchial and lung epithelium, the inhalative administration of a stable isotope labelled agent appeared more suitable to us. [1-13C]Hexadecanol and [1-13C]glucose were chosen. Inhaled [1-13C]hexadecanol did not yield 13CO2 in the exhaled air, but [1-13C]glucose did. To study the practicability of the [1-13C]glucose method and the reproducibility of the results, 18 inhalation tests were performed with healthy subjects. In 6 self-tests, the optimum inhalative dose of [13C]glucose was determined to be 205 mg. Using the APS aerosol provocation system with the nebulizer 'Medic Aid' (Erich Jaeger Würzburg), a 25% aqueous solution was inhaled. Then, breath samples were collected at 15 min. intervals and analysed for 13CO2. 75-120 min after the end of inhalation a well-reproducible maximum delta13C value of 6%o over baseline (DOB) was detected for 12 healthy probands. Speculating that the pulmonary resorption of the [13C]glucose is the rate-limiting step of elimination, decompensations in the epithelium ought to be reflected in changed [1-13C]glucose resorption rates and changed 13CO2 output. Therefore, we speculate that the inhalation of suitable 13C-labelled substrates will pave the way for a new group of 13CO2 breath tests aiding investigations of specific pathophysiological changes in the pulmonary tract, such as inflammations of certain sections and decompensations of cell functions.

  4. Optoacoustic 13C-breath test analyzer

    NASA Astrophysics Data System (ADS)

    Harde, Hermann; Helmrich, Günther; Wolff, Marcus

    2010-02-01

    The composition and concentration of exhaled volatile gases reflects the physical ability of a patient. Therefore, a breath analysis allows to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that employs a compact and simple set-up based on photoacoustic spectroscopy. It consists of two identical photoacoustic cells containing two breath samples, one taken before and one after capturing an isotope-marked substrate, where the most common isotope 12C is replaced to a large extent by 13C. The analyzer measures simultaneously the relative CO2 isotopologue concentrations in both samples by exciting the molecules on specially selected absorption lines with a semiconductor laser operating at a wavelength of 2.744 μm. For a reliable diagnosis changes of the 13CO2 concentration of 1% in the exhaled breath have to be detected at a concentration level of this isotope in the breath of about 500 ppm.

  5. Breath alcohol test

    MedlinePlus

    ... of alcohol in the air you breathe out (exhale). How the Test is Performed There are many ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  6. Stability of (13) C-Urea Breath Test Samples Over Time in the Diagnosis of Helicobacter pylori.

    PubMed

    Perets, Tsachi Tsadok; Shporn, Einav; Boltin, Doron; Dickman, Ram; Niv, Yaron

    2016-05-01

    The accuracy and repeatability of breath test in the diagnosis of Helicobacter pylori infection have not been adequately investigated. Although it has been shown that storage for long periods does not affect the analysis results, no data are available on the effect of repetitive testing. In this study, our aim was to evaluate the repeatability of the analyses of breath samples at room temperature. A total of 202 positive breath samples were collected in duplicates, before and after administration of 75 mg (13) C- urea dissolved in 100 ml of orange juice. Breath test results were expressed as delta (13) CO2 . The cut-off value was 3.5 parts per thousand. Each sample was analyzed in a mass spectrometer 7, 14, 21, and 28 days after collection. The accuracy calculation was based on the comparison of the delta (13) CO2 obtained in the three consecutive weeks following the first test run to the delta (13) CO2 obtained in the first test run. Two hundred (99%), 197 (97.52%), and 196 (97%) of the 202 samples tested positive in the second, third, and fourth test runs, respectively. The accuracy of the delta (13) CO2 was 98.6%, 99.2%, and 96.7% in the three consecutive runs, respectively. Short-term storage of 1 month does not affect sample stability or the results of (13) C-urea breath tests in up to three consecutive repeats. © 2015 Wiley Periodicals, Inc.

  7. 13[C]-Urea Breath Test as a Novel Point-of-Care Biomarker for Tuberculosis Treatment and Diagnosis

    PubMed Central

    Jassal, Mandeep S.; Nedeltchev, Gueno G.; Lee, Jong-Hee; Choi, Seong Won; Atudorei, Viorel; Sharp, Zachary D.; Deretic, Vojo; Timmins, Graham S.; Bishai, William R.

    2010-01-01

    Background Pathogen-specific metabolic pathways may be detected by breath tests based on introduction of stable isotopically-labeled substrates and detection of labeled products in exhaled breath using portable infrared spectrometers. Methodology/Principal Findings We tested whether mycobacterial urease activity could be utilized in such a breath test format as the basis of a novel biomarker and diagnostic for pulmonary TB. Sensitized New-Zealand White Rabbits underwent bronchoscopic infection with either Mycobacterium bovis or Mycobacterium tuberculosis. Rabbits were treated with 25 mg/kg of isoniazid (INH) approximately 2 months after infection when significant cavitary lung pathology was present. [13C] urea was instilled directly into the lungs of intubated rabbits at selected time points, exhaled air samples analyzed, and the kinetics of δ13CO2 formation were determined. Samples obtained prior to inoculation served as control samples for background 13CO2 conversion in the rabbit model. 13CO2, from metabolic conversion of [13C]-urea by mycobacterial urease activity, was readily detectable in the exhaled breath of infected rabbits within 15 minutes of administration. Analyses showed a rapid increase in the rate of 13CO2 formation both early in disease and prior to treatment with INH. Following INH treatment, all evaluable rabbits showed a decrease in the rate of 13CO2 formation. Conclusions/Significance Urea breath testing may provide a useful diagnostic and biomarker assay for tuberculosis and for treatment response. Future work will test specificity for M. tuberculosis using lung-targeted dry powder inhalation formulations, combined with co-administering oral urease inhibitors together with a saturating oral dose of unlabeled urea, which would prevent the δ13CO2 signal from urease-positive gastrointestinal organisms. PMID:20805989

  8. 13[C]-urea breath test as a novel point-of-care biomarker for tuberculosis treatment and diagnosis.

    PubMed

    Jassal, Mandeep S; Nedeltchev, Gueno G; Lee, Jong-Hee; Choi, Seong Won; Atudorei, Viorel; Sharp, Zachary D; Deretic, Vojo; Timmins, Graham S; Bishai, William R

    2010-08-27

    Pathogen-specific metabolic pathways may be detected by breath tests based on introduction of stable isotopically-labeled substrates and detection of labeled products in exhaled breath using portable infrared spectrometers. We tested whether mycobacterial urease activity could be utilized in such a breath test format as the basis of a novel biomarker and diagnostic for pulmonary TB. Sensitized New-Zealand White Rabbits underwent bronchoscopic infection with either Mycobacterium bovis or Mycobacterium tuberculosis. Rabbits were treated with 25 mg/kg of isoniazid (INH) approximately 2 months after infection when significant cavitary lung pathology was present. [(13)C] urea was instilled directly into the lungs of intubated rabbits at selected time points, exhaled air samples analyzed, and the kinetics of delta(13)CO(2) formation were determined. Samples obtained prior to inoculation served as control samples for background (13)CO(2) conversion in the rabbit model. (13)CO(2), from metabolic conversion of [(13)C]-urea by mycobacterial urease activity, was readily detectable in the exhaled breath of infected rabbits within 15 minutes of administration. Analyses showed a rapid increase in the rate of (13)CO(2) formation both early in disease and prior to treatment with INH. Following INH treatment, all evaluable rabbits showed a decrease in the rate of (13)CO(2) formation. Urea breath testing may provide a useful diagnostic and biomarker assay for tuberculosis and for treatment response. Future work will test specificity for M. tuberculosis using lung-targeted dry powder inhalation formulations, combined with co-administering oral urease inhibitors together with a saturating oral dose of unlabeled urea, which would prevent the delta(13)CO(2) signal from urease-positive gastrointestinal organisms.

  9. Breath testing with a mid-IR laser spectrometer

    NASA Astrophysics Data System (ADS)

    Namjou, Khosrow; McCann, Patrick J.; Potter, William T.

    1999-10-01

    A mid-IR tunable diode laser absorption spectrometer (TDLAS) equipped with a multiple-pass gas cell was used to measure breath samples from a number of student volunteers at the University of Oklahoma. Test subjects included one to two pack-a-day cigarette smokers and non-smokers. The concentrations of four different molecules, N2O, 12CO2, 13CO2 and CO, were measured by each laser scan in the 2206.1 cm-1 to 2207 cm-1 spectral range. The average concentration of nitrous oxide (N2O) increased slightly for smokers versus non-smokers and was generally higher (12%) than the approximately 255 ppm concentration measured in ambient air. Carbon monoxide concentrations, however, were much higher in breath samples from cigarette smokers. Ambient concentrations of carbon monoxide, approximately 0.4 ppm, increased from approximately 1.0 ppm in non-smokers to levels over 13.4 ppm in smokers. These measurements provide clear evidence of the well-known effect that cigarette smoking has on replacing oxygen with carbon monoxide in human hemoglobin. Carbon dioxide concentrations of smokers were generally decreased by approximately 12%. Mid-IR laser measurements also provided 13CO2/12CO2 isotope ratio values, and smokers had a approximately 30% greater concentration of isotopic 13C in their breath. The possible mechanisms for 13CO2 isotopic increases are at present unknown. Overall, long-path TDL spectroscopy of exhalation products is a uniquely powerful tool. The TDL systems can be used for noninvasive diagnosis of a wide range of metabolisms and pathologies.

  10. Minimally invasive (13)C-breath test to examine phenylalanine metabolism in children with phenylketonuria.

    PubMed

    Turki, Abrar; Murthy, Gayathri; Ueda, Keiko; Cheng, Barbara; Giezen, Alette; Stockler-Ipsiroglu, Sylvia; Elango, Rajavel

    2015-01-01

    Phenylketonuria (PKU) is an autosomal recessive disorder caused by deficiency of hepatic phenylalanine hydroxylase (PAH) leading to increased levels of phenylalanine in the plasma. Phenylalanine levels and phenylalanine hydroxylase (PAH) activity monitoring are currently limited to conventional blood dot testing. 1-(13)C-phenylalanine, a stable isotope can be used to examine phenylalanine metabolism, as the conversion of phenylalanine to tyrosine occurs in vivo via PAH and subsequently releases the carboxyl labeled (13)C as (13)CO2 in breath. Our objective was to examine phenylalanine metabolism in children with PKU using a minimally-invasive 1-(13)C-phenylalanine breath test ((13)C-PBT). Nine children (7 M: 2 F, mean age 12.5 ± 2.87 y) with PKU participated in the study twice: once before and once after sapropterin supplementation. Children were provided 6 mg/kg oral dose of 1-(13)C-phenylalanine and breath samples were collected at 20 min intervals for a period of 2h. Rate of CO2 production was measured at 60 min post-oral dose using indirect calorimetry. The percentage of 1-(13)C-phenylalanine exhaled as (13)CO2 was measured over a 2h period. Prior to studying children with PKU, we tested the study protocol in healthy children (n = 6; 4M: 2F, mean age 10.2 ± 2.48 y) as proof of principle. Production of a peak enrichment (Cmax) of (13)CO2 (% of dose) in all healthy children occurred at 20 min ranging from 17-29% of dose, with a subsequent return to ~5% by the end of 2h. Production of (13)CO2 from 1-(13)C-phenylalanine in all children with PKU prior to sapropterin treatment remained low. Following sapropterin supplementation for a week, production of (13)CO2 significantly increased in five children with a subsequent decline in blood phenylalanine levels, suggesting improved PAH activity. Sapropterin treatment was not effective in three children whose (13)CO2 production remained unchanged, and did not show a reduction in blood phenylalanine levels and improvement

  11. Hydrogen breath test in schoolchildren.

    PubMed

    Douwes, A C; Schaap, C; van der Klei-van Moorsel, J M

    1985-04-01

    The frequency of negative hydrogen breath tests due to colonic bacterial flora which are unable to produce hydrogen was determined after oral lactulose challenge in 98 healthy Dutch schoolchildren. There was a negative result in 9.2%. The probability of a false normal lactose breath test (1:77) was calculated from these results together with those from a separate group of children with lactose malabsorption (also determined by hydrogen breath test). A study of siblings and mothers of subjects with a negative breath test did not show familial clustering of this condition. Faecal incubation tests with various sugars showed an increase in breath hydrogen greater than 100 parts per million in those with a positive breath test while subjects with a negative breath test also had a negative faecal incubation test. The frequency of a false negative hydrogen breath test was higher than previously reported, but this does not affect the superiority of this method of testing over the conventional blood glucose determination.

  12. Clinical applications of breath testing

    PubMed Central

    Paschke, Kelly M; Mashir, Alquam

    2010-01-01

    Breath testing has the potential to benefit the medical field as a cost-effective, non-invasive diagnostic tool for diseases of the lung and beyond. With growing evidence of clinical worth, standardization of methods, and new sensor and detection technologies the stage is set for breath testing to gain considerable attention and wider application in upcoming years. PMID:21173863

  13. Comparison of Catabolic Rates of sn-1, sn-2, and sn-3 Fatty Acids in Triacylglycerols Using (13)CO2 Breath Test in Mice.

    PubMed

    Beppu, Fumiaki; Kawamatsu, Takashi; Yamatani, Yoshio; Nagai, Toshiharu; Yoshinaga, Kazuaki; Mizobe, Hoyo; Yoshida, Akihiko; Kubo, Atsushi; Kanda, Jota; Gotoh, Naohiro

    2017-01-01

    Fatty acids in triacylglycerols (TAGs) are catabolized after digestion. However, the catabolic rates of the fatty acids at the sn-1, sn-2, and sn-3 positions of TAGs have not been compared. To elucidate the differences, we studied the catabolic rates of (13)C-labeled palmitic acid, oleic acid, and capric acid at the sn-1, sn-2, or sn-3 position of TAGs using isotope-ratio mass spectrometry. Specifically, we measured the (13)C-to-(12)C ratio in CO2 (Δ(13)C (‰)) exhaled by mice. For all analyzed fatty acids, we observed significant differences between sn-2 and other binding positions. In contrast, no significant difference was detected between the sn-1 and sn-3 positions. These results indicated that the catabolic rates of fatty acids are strongly influenced by their positions in TAGs.

  14. Factors affecting the validity of the 13C-urea breath test for in vivo determination of Helicobacter pylori infection status in a mouse model.

    PubMed

    Hammond, P D; Stutzenberger, F J; Butler, R N; Read, L C; Davidson, G P

    1999-12-01

    The mouse model using a human isolate of Helicobacter pylori is being widely accepted as an economical means of studying gastric infection. A noninvasive monitoring method would be useful for repeated testing to establish the time course of infection and the efficacy of treatments. In this study, we describe factors that affected interpretation of 13C urea breath test results for the assessment of H. pylori infection status in this model. Female C57B1/6 mice that underwent gavage with H. pylori or saline were breath-tested using 50 micrograms of 13C urea at intervals up to 2 months after inoculation. The generation of 13CO2 (excess delta 13CO2) by infected mice was compared to that of uninfected controls. The effects of diet, fasting, and coprophagy on the reliability of the 13C urea breath test were quantitated. Both commercial and synthetic mouse diets exhibited marked in vitro urease activity. A minimum fasting time of 13 hours prior to breath testing significantly reduced this dietary contribution to excess delta 13CO2 values. The coprophagic tendency of the mice caused spuriously high excess delta 13CO2 counts in the breath of both control and H. pylori-infected mice. Although the dietary contribution to spuriously high values of excess delta 13CO2 in mice breath-tested for H. pylori infection was reduced by fasting, the high nonspecific urease activity generated by coprophagy severely limited the reliability of the urea breath test in the assessment of H. pylori infection status.

  15. Tracking the oxidative kinetics of carbohydrates, amino acids and fatty acids in the house sparrow using exhaled 13CO2.

    PubMed

    McCue, M D; Sivan, O; McWilliams, S R; Pinshow, B

    2010-03-01

    Clinicians commonly measure the (13)CO(2) in exhaled breath samples following administration of a metabolic tracer (breath testing) to diagnose certain infections and metabolic disorders. We believe that breath testing can become a powerful tool to investigate novel questions about the influence of ecological and physiological factors on the oxidative fates of exogenous nutrients. Here we examined several predictions regarding the oxidative kinetics of specific carbohydrates, amino acids and fatty acids in a dietary generalist, the house sparrow (Passer domesticus). After administering postprandial birds with 20 mg of one of seven (13)C-labeled tracers, we measured rates of (13)CO(2) production every 15 min over 2 h. We found that sparrows oxidized exogenous amino acids far more rapidly than carbohydrates or fatty acids, and that different tracers belonging to the same class of physiological fuels had unique oxidative kinetics. Glycine had a mean maximum rate of oxidation (2021 nmol min(-1)) that was significantly higher than that of leucine (351 nmol min(-1)), supporting our prediction that nonessential amino acids are oxidized more rapidly than essential amino acids. Exogenous glucose and fructose were oxidized to a similar extent (5.9% of dose), but the time required to reach maximum rates of oxidation was longer for fructose. The maximum rates of oxidation were significantly higher when exogenous glucose was administered as an aqueous solution (122 nmol min(-1)), rather than as an oil suspension (93 nmol min(-1)), supporting our prediction that exogenous lipids negatively influence rates of exogenous glucose oxidation. Dietary fatty acids had the lowest maximum rates of oxidation (2-6 nmol min(-1)), and differed significantly in the extent to which each was oxidized, with 0.73%, 0.63% and 0.21% of palmitic, oleic and stearic acid tracers oxidized, respectively.

  16. 13C-urea breath test for diagnosis of experimental Helicobacter pylori infection in barrier born pigs.

    PubMed Central

    Meyer-Rosberg, K; Gustavsson, S

    1993-01-01

    Previous studies with Helicobacter pylori infected barrier born pigs indicate that the infection has a patchy distribution, resulting in false negative culture results on endoscopic biopsy specimens. This study aimed to adapt the 13C-urea breath test as used in humans to diagnose H pylori infection in barrier born pigs. The breath test was also performed after bismuth as a single treatment and after triple therapy (bismuth, ampicillin, metronidazole). In control pigs the median excess of 13CO2 in expired air was 2.2 (range 0-12 n = 22) ppm. The infected pigs (n = 4) showed consistently high values (median 23 range 14-43) when examined on four occasions (n = 16) four to 10 weeks after inoculation. Biopsy specimens for culture had lower sensitivity than the breath test. No reduction in excess 13CO2 was seen after three days' single bismuth treatment, but after two weeks' triple therapy the breath test results had returned to normal. This suppression was temporary only, however, as the breath test was positive again four weeks after stopping treatment. In conclusion, the 13C-urea breath test is a simple and reliable test for determining H pylori infection and monitoring treatment effects in barrier born pigs. Because the test can be performed in awake pigs anaesthesia and gastroscopy are unnecessary. Images Figure 1 PMID:8504957

  17. 13C-urea breath test for diagnosis of experimental Helicobacter pylori infection in barrier born pigs.

    PubMed

    Meyer-Rosberg, K; Gustavsson, S

    1993-05-01

    Previous studies with Helicobacter pylori infected barrier born pigs indicate that the infection has a patchy distribution, resulting in false negative culture results on endoscopic biopsy specimens. This study aimed to adapt the 13C-urea breath test as used in humans to diagnose H pylori infection in barrier born pigs. The breath test was also performed after bismuth as a single treatment and after triple therapy (bismuth, ampicillin, metronidazole). In control pigs the median excess of 13CO2 in expired air was 2.2 (range 0-12 n = 22) ppm. The infected pigs (n = 4) showed consistently high values (median 23 range 14-43) when examined on four occasions (n = 16) four to 10 weeks after inoculation. Biopsy specimens for culture had lower sensitivity than the breath test. No reduction in excess 13CO2 was seen after three days' single bismuth treatment, but after two weeks' triple therapy the breath test results had returned to normal. This suppression was temporary only, however, as the breath test was positive again four weeks after stopping treatment. In conclusion, the 13C-urea breath test is a simple and reliable test for determining H pylori infection and monitoring treatment effects in barrier born pigs. Because the test can be performed in awake pigs anaesthesia and gastroscopy are unnecessary.

  18. Can Breath Test Detect Stomach Cancers Earlier?

    MedlinePlus

    ... news/fullstory_163342.html Can Breath Test Detect Stomach Cancers Earlier? New technology may also spot esophageal ... 2017 (HealthDay News) -- A breath test to detect stomach and esophageal cancers shows promise, researchers say. The ...

  19. 13CO2/12CO2 ratio analysis in exhaled air by lead-salt tunable diode lasers for noninvasive diagnostics in gastroenterology

    NASA Astrophysics Data System (ADS)

    Stepanov, Eugene V.; Zyrianov, Pavel V.; Miliaev, Valerii A.; Selivanov, Yurii G.; Chizhevskii, Eugene G.; Os'kina, Svetlana; Ivashkin, Vladimir T.; Nikitina, Elena I.

    1999-07-01

    An analyzer of 13CO2/12CO2 ratio in exhaled air based on lead-salt tunable diode lasers is presented. High accuracy of the carbon isotope ratio detection in exhaled carbon dioxide was achieved with help of very simple optical schematics. It was based on the use of MBE laser diodes operating in pulse mode and on recording the resonance CO2 absorption at 4.2 micrometers . Special fast acquisition electronics and software were applied for spectral data collection and processing. Developed laser system was tested in a clinical train aimed to assessment eradication efficiency in therapy of gastritis associated with Helicobacter pylori infection. Data on the 13C-urea breath test used for P.pylori detection and obtained with tunable diode lasers in the course of the trail was compared with the results of Mass-Spectroscopy analysis and histology observations. The analyzer can be used also for 13CO2/12CO2 ratio detection in exhalation to perform gastroenterology breath test based on using other compounds labeled with stable isotopes.

  20. Effects of tetrahydrobiopterin and phenylalanine on in vivo human phenylalanine hydroxylase by phenylalanine breath test.

    PubMed

    Okano, Yoshiyuki; Takatori, Kazuhiko; Kudo, Satoshi; Sakaguchi, Tomoko; Asada, Minoru; Kajiwara, Masahiro; Yamano, Tsunekazu

    2007-12-01

    BH(4) administration results in the reduction of blood phenylalanine level in patients with tetrahydrobiopterin (BH(4))-responsive phenylalanine hydroxylase (PAH) deficiency. The mechanism underlying BH(4) response remains unknown. Here, we studied the effects of BH(4) and phenylalanine on in vivo PAH activity of normal controls using the phenylalanine breath test (PBT) by converting l-[1-(13)C] phenylalanine to (13)CO(2). Phenylalanine oxidation rates were expressed as Delta(13)C ((13)CO(2)/(12+13)CO(2), per thousand) and cumulative recovery rates over 120min (CRR(120), %; total amount of (13)CO(2)/the administered dose of (13)C-phenylalanine). Under physiological conditions of blood phenylalanine, BH(4) administration reduced the Delta(13)C peak from 40.8 per thousand to 21.6 per thousand and CRR(120) from 16.9% to 10.2%. Under high blood phenylalanine conditions, administration of BH(4) increased the Delta(13)C peak from 30.7 per thousand to 46.0 per thousand, while the CRR(120) was similar between phenylalanine (19.9%) and phenylalanine+BH(4) (21.1%) groups. Corrected Delta(13)C and CRR(120) were calculated against serum phenylalanine levels to remove the effects of phenylalanine loading. After BH(4) administration, the corrected Delta(13)C peak increased from 82.7 per thousand to 112.6 per thousand, while the corrected CRR(120) was similar (47.6% and 45.6%). These results indicate that phenylalanine worked as a regulator of in vivo PAH by serving as both a substrate and an activator for the enzyme. Excessive dosages of BH(4) inhibited PAH under normal phenylalanine conditions and activated PAH under conditions of high phenylalanine. The regulation system is therefore designed to maintain phenylalanine levels in the human body. Appropriate BH(4) supplementation must be reviewed in patients with BH(4)-responsive PAH deficiency.

  1. [Breath-analysis tests in gastroenetrological diagnosis].

    PubMed

    Caspary, W F

    1975-12-01

    The introduction of a simple method for analysis of 14CO2 in breath allowed a more widely application of breath-tests in the diagnosis of gastroenterological diseases. During a breath-test a 14C-labelled compound is administered orally and 14CO2 is subsequently measured in breath by discontinuous samplings of 14CO2 by virtue of a trapping solution (hyamine hydroxide). Most helpful tests in gastroenterology are the 14C-glycyl-cholate breath test for detecting increased deconjugation of bile acids due to small intestinal bacterial overgrowth or bile acid malabsorption in ileal resection or Crohn's disease of the ileum, the 14C-lactose breath test in lactase deficiency, whereas the 14C-tripalmitin test seems less helpful in the diagnosis of fat malabsorption. A 14C-aminopyrine breath test may turn out to be a simple and valuable liver function test. Oral loading tests with breath analysis of H2 have shown to be helpful in the diagnosis of carbohydrate malabsorption, determination of intestinal transit time and intestinal gas production. Due to technical reasons (gas-chromatographie analysis) H2-breath analysis is still limited to research centers. Despite low radiation doses after oral administration of 14C-labelled compounds oral loading tests with H2- or 13C-analysis might be preferable in the future.

  2. Estimation of Insulin Resistance in Mexican Adults by the [(13)C]Glucose Breath Test Corrected for Endogenous Total CO(2) Production.

    PubMed

    Ibarra-Pastrana, Erika; Candia Plata, Maria Del Carmen; Alvarez, Gerardo; Valencia, Mauro E

    2012-01-01

    Objective. To evaluate the efficacy of the [(13)C]glucose breath test for measuring insulin resistance in Mexican adults with different glycemic states. Research Design and Methods. Fifty-eight adults underwent a [(13)C]glucose breath test with simultaneous measurement of total CO(2) production by indirect calorimetry, at baseline and 90 minutes after the ingestion of 15 g of dextrose and 25 mg of [(13)C]glucose. HOMA was used as a marker of insulin resistance. Results. We found an inverse correlation between HOMA and the breath test δ(13)CO(2) (‰), r = -0.41 (P = 0.001). After adjusting for total CO(2) production, correlations between HOMA and fasting glucose were less strong but remained significant. An ROC curve was constructed using δ(13)CO(2) (‰) and HOMA values; the cut-off point was 9.99‰ δ(13)CO(2), corresponding to a sensitivity of 80.0 (95% CI: 51.9, 95.7) and a specificity of 67.4 (95% CI: 51.5, 80.9). Conclusions. The [(13)C]glucose breath test is a simple noninvasive procedure but was not sufficiently robust for an accurate diagnosis of insulin resistance. Our findings suggest that the test might be helpful in identifying individuals who are not IR, which in turn may contribute to improved diabetes prevention.

  3. Estimation of Insulin Resistance in Mexican Adults by the [13C]Glucose Breath Test Corrected for Endogenous Total CO2 Production

    PubMed Central

    Ibarra-Pastrana, Erika; Candia Plata, Maria del Carmen; Alvarez, Gerardo; Valencia, Mauro E.

    2012-01-01

    Objective. To evaluate the efficacy of the [13C]glucose breath test for measuring insulin resistance in Mexican adults with different glycemic states. Research Design and Methods. Fifty-eight adults underwent a [13C]glucose breath test with simultaneous measurement of total CO2 production by indirect calorimetry, at baseline and 90 minutes after the ingestion of 15 g of dextrose and 25 mg of [13C]glucose. HOMA was used as a marker of insulin resistance. Results. We found an inverse correlation between HOMA and the breath test δ 13CO2 (‰), r = −0.41 (P = 0.001). After adjusting for total CO2 production, correlations between HOMA and fasting glucose were less strong but remained significant. An ROC curve was constructed using δ 13CO2 (‰) and HOMA values; the cut-off point was 9.99‰ δ 13CO2, corresponding to a sensitivity of 80.0 (95% CI: 51.9, 95.7) and a specificity of 67.4 (95% CI: 51.5, 80.9). Conclusions. The [13C]glucose breath test is a simple noninvasive procedure but was not sufficiently robust for an accurate diagnosis of insulin resistance. Our findings suggest that the test might be helpful in identifying individuals who are not IR, which in turn may contribute to improved diabetes prevention. PMID:22848216

  4. 13C-phenylalanine breath test detects altered phenylalanine kinetics in schizophrenia patients

    PubMed Central

    Teraishi, T; Ozeki, Y; Hori, H; Sasayama, D; Chiba, S; Yamamoto, N; Tanaka, H; Iijima, Y; Matsuo, J; Kawamoto, Y; Kinoshita, Y; Hattori, K; Ota, M; Kajiwara, M; Terada, S; Higuchi, T; Kunugi, H

    2012-01-01

    Phenylalanine is an essential amino acid required for the synthesis of catecholamines including dopamine. Altered levels of phenylalanine and its metabolites in blood and cerebrospinal fluid have been reported in schizophrenia patients. This study attempted to examine for the first time whether phenylalanine kinetics is altered in schizophrenia using L-[1-13C]phenylalanine breath test (13C-PBT). The subjects were 20 chronically medicated schizophrenia patients (DSM-IV) and the same number of age- and sex-matched controls. 13C-phenylalanine (99 atom% 13C; 100 mg) was administered orally and the breath 13CO2 /12CO2 ratio was monitored for 120 min. The possible effect of antipsychotic medication (risperidone (RPD) or haloperidol (HPD) treatment for 21 days) on 13C-PBT was examined in rats. Body weight (BW), age and diagnostic status were significant predictors of the area under the curve of the time course of Δ13CO2 (‰) and the cumulative recovery rate (CRR) at 120 min. A repeated measures analysis of covariance controlled for age and BW revealed that the patterns of CRR change over time differed between the patients and controls and that Δ13CO2 was lower in the patients than in the controls at all sampling time points during the 120 min test, with an overall significant difference between the two groups. Chronic administration of RPD or HPD had no significant effect on 13C-PBT indices in rats. Our results suggest that 13C-PBT is a novel laboratory test that can detect altered phenylalanine kinetics in chronic schizophrenia patients. Animal experiments suggest that the observed changes are unlikely to be attributable to antipsychotic medication. PMID:22832963

  5. Accuracy of 13C-urea breath test in clinical use for diagnosis of Helicobacter pylori infection.

    PubMed

    Riepl, R L; Folwaczny, C; Otto, B; Klauser, A; Blendinger, C; Wiebecke, B; König, A; Lehnert, P; Heldwein, W

    2000-01-01

    The 13C-urea breath test (UBT) is a noninvasive test for diagnosis of Helicobacter pylori infection of gastric mucosa. The aim of this prospective study was to assess the accuracy of a simple UBT in clinical routine use. The study population comprised of 100 patients (49 f, 51 m) requiring diagnostic upper GI endoscopy. One biopsy specimen was taken from the gastric antrum, body and fundus, respectively, for standard histological examination and one additional specimen from each location was transformed into transport medium for cultivation of H. pylori. After vaccination of the culture plates the biopsies were tested for urease activity (UAT). After recovery from endoscopy the patients had to pass an one liter endexspiratory breath sample before and 15 min after drinking 200 ml orange juice, pH 3.6, containing 75 mg of 13C-urea. 13CO2 was measured in the breath samples using isotope-selective nondispersive infrared spectrometry. Defining gold standard groups with all biopsy tests (from antrum and corpus) positive or negative the 13CO2 delta over baseline (DOB) cut-off level of UBT was set at 6.5/1000 in order to best discriminate positive from negative patients (ROC analysis). UBT was positive in 37% of all subjects. Taken UAT and histological examination together (positive when both tests were positive) UBT displayed a sensitivity of 92%, a specificity of 94%, a positive predictive value of 89%, and a negative predictive value of 94%. When including the results of culture sensitivity and negative predictive value reached almost 100%. The mean of the 13CO2-DOB values from H. pylori-positive duodenal or gastric ulcer patients did not differ from controls (H. pylori-positive patients without lesions). The 13CO2-DOB values of the ulcer group were correlated significantly with the active inflammatory component of gastritis in antrum, corpus, and fundus. UBT with this setup detects H. pylori infection in clinical routine use with high accuracy. The increase of exhaled

  6. Effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying evaluated using a non-invasive breath test in conscious rats

    PubMed Central

    Uchida, Masayuki; Kobayashi, Orie; Iwasawa, Kaori; Shimizu, Kimiko

    2016-01-01

    Aim: Some amino acids been known to influence gastric emptying. Thus we have evaluated the effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying. Materials and Methods: Gastric emptying was evaluated in rats after feeding with Racol (nutrient formulae) containing [1-13C] acetic acid. Using a breath test, the content of 13CO2 in their expired air was measured by infrared analyzers. Rats were orally administered with test amino acids, while control rats were administered orally with distilled water. Results: The expired 13CO2 content in the expired air increased with time, peaked after about 30 min and decreased thereafter. Among the amino acids having an alkyl chain, l-serine, l-alanine and l-glycine, significantly decreased the 13CO2 content and Cmax, and delayed Tmax, suggesting inhibition and delay of gastric emptying. AUC120 min values of l-alanine and l-glycine also decreased significantly. l-Threonine significantly decreased 13CO2 content and delayed Tmax, but had no influence on Cmax and AUC120 min values, suggesting a delay of gastric emptying. l-Isoleucine and l-leucine and l-valine significantly decreased 13CO2 content, suggesting inhibition of the gastric emptying, but Cmax, Tmax and AUC120 min values were not significantly affected. Conclusion: The results show that the amino acids used in the present study had different effects on gastric emptying. Moreover, it was found that inhibition and delay of gastric emptying were clearly classifiable by analyzing the change in 13CO2 content of the expired air and the Cmax, Tmax and AUC120 min values. PMID:27169776

  7. Adaptation of the [13C]urea breath test as a noninvasive method for detection of Helicobacter pylori infection in squirrel monkeys (Saimiri spp.).

    PubMed

    Stadtländer, C T; Stutzenberger, F J

    1995-06-01

    The [13C]urea breath test was adapted for use in squirrel monkeys (Saimiri spp.) for identification of experimentally induced infection with Helicobacter pylori, the bacterium causing gastric ulcer in humans. A canine anesthesia inhalation mask was modified with a volume-reducing insert allowing sufficient breath collection from these small primates within 30 sec. Fourteen milligrams of [13C urea per kilogram of body weight was adequate for clear distinction between experimentally infected and noninfected animals. Initial infection of five squirrel monkeys resulted in increased 13CO2 in breath within 3 days after inoculation with H. pylori. Additional inoculation with H. pylori superimposed on an existing gastric population caused a transient increase in breath 13CO2 values, which gradually declined over the following 15 days. Breath test results indicating H. pylori infection were confirmed by high [13C] concentration in blood, by urease-positive culture, modified Steiner stain reaction, and Western blot analysis. This modified [13C]urea breath test provides a rapid, reproducible, noninvasive method for screening small primates used as nonhuman models for the study of gastric infection with H. pylori.

  8. Evaluation of a [13C]-Dextromethorphan Breath Test to Assess CYP2D6 Phenotype

    PubMed Central

    Leeder, J. Steven; Pearce, Robin E.; Gaedigk, Andrea; Modak, Anil; Rosen, David I.

    2016-01-01

    A [13C]-dextromethorphan ([13C]-DM) breath test was evaluated to assess its feasibility as a rapid, phenotyping assay for CYP2D6 activity. [13C]-DM (0.5 mg/kg) was administered orally with water or potassium bicarbonate-sodium bicarbonate to 30 adult Caucasian volunteers (n = 1 each): CYP2D6 poor metabolizers (2 null alleles; PM-0) and extensive metabolizers with 1 (EM-1) or 2 functional alleles (EM-2). CYP2D6 phenotype was determined by 13CO2 enrichment measured by infrared spectrometry (delta-over-baseline [DOB] value) in expired breath samples collected before and up to 240 minutes after [13C]-DM ingestion and by 4-hour urinary metabolite ratio. The PM-0 group was readily distinguishable from either EM group by both the breath test and urinary metabolite ratio. Using a single point determination of phenotype at 40 minutes and defining PMs as subjects with a DOB ≤ 0.5, the sensitivity of the method was 100%; specificity was 95% with 95% accuracy and resulted in the misclassification of 1 EM-1 individual as a PM. Modification of the initial protocol (timing of potassium bicarbonate-sodium bicarbonate administration relative to dose) yielded comparable results, but there was a tendency toward increased DOB values. Although further development is required, these studies suggest that the [13C]-DM breath test offers promise as a rapid, minimally invasive phenotyping assay for CYP2D6 activity. PMID:18728242

  9. The clinical value of breath hydrogen testing.

    PubMed

    Yao, Chu K; Tuck, Caroline J

    2017-03-01

    Breath hydrogen testing for assessing the presence of carbohydrate malabsorption is frequently applied to refine dietary restrictions on a low fermentable carbohydrate (FODMAP) diet. Its application has also been extended for the detection of small intestinal bacterial overgrowth. Recently, several caveats of its methodology and interpretation have emerged. A review of the evidence surrounding its application in the management of patients with a functional bowel disorder was performed. Studies were examined to assess limitations of testing methodology, interpretation of results, reproducibility, and how this relates to clinical symptoms. A wide heterogeneity in testing parameters, definition of positive/negative response, and the use of clinically irrelevant doses of test carbohydrate were common methodological limitations. These factors can subsequently impact the sensitivity, specificity, and false positive or negative detection rates. Evidence is also increasing on the poor intra-individual reproducibility in breath responses with repeated testing for fructose and lactulose. On the basis of these limitations, it is not surprising that the diagnosis of small intestinal bacterial overgrowth based on a lactulose breath test yields a wide prevalence rate and is unreliable. Finally, symptom induction during a breath test has been found to correlate poorly with the presence of carbohydrate malabsorption. The evidence suggests that breath hydrogen tests have limited clinical value in guiding clinical decision for the patient with a functional bowel disorder. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  10. Impact of oceanic circulation changes on atmospheric δ13CO2

    NASA Astrophysics Data System (ADS)

    Menviel, L.; Mouchet, A.; Meissner, K. J.; Joos, F.; England, M. H.

    2015-12-01

    δ13CO2 measured in Antarctic ice cores provides constraints on oceanic and terrestrial carbon cycle processes linked with millennial-scale and glacial/interglacial changes in atmospheric CO2. However, the interpretation of δ13CO2 is not straightforward. Using two Earth system models of intermediate complexity we perform a set of sensitivity experiments in which the formation rates of North Atlantic Deep Water (NADW), North Pacific Deep Water (NPDW), Antarctic Bottom Water (AABW) and Antarctic Intermediate Water (AAIW) are varied. We study the impact of these circulation changes on atmospheric δ13CO2 as well as on the oceanic δ13C distribution. In general, we find that the formation rates of AABW, NADW, NPDW and AAIW are negatively correlated with changes in δ13CO2: namely strong oceanic ventilation decreases atmospheric δ13CO2. However, since large scale ocean circulation reorganizations also impact nutrient utilization and the Earth's climate the relationship between atmospheric δ13CO2 levels and ocean ventilation rate is not unequivocal. In both models atmospheric δ13CO2 is very sensitive to changes in AABW formation rates: increased AABW formation enhances the upwelling of low δ13C waters to the surface and decreases atmospheric δ13CO2. By contrast, the impact of NADW changes on atmospheric δ13CO2 is less robust and might be model dependent.

  11. Regulatory issues on breath tests and updates of recent advances on [13C]-breath tests.

    PubMed

    Modak, Anil S

    2013-09-01

    Over the last decade non invasive diagnostic phenotype [(13)C]-breath tests as well as tests using endogenous volatile organic compounds (VOCs) in breath have been researched extensively. However, only three breath tests have been approved by the FDA over the last 15 years. Despite the potential benefits of these companion diagnostic tests (CDx) for evaluation of drug metabolizing enzyme activities and standalone diagnostic tests for disease diagnosis to personalize medicine, the clinical and commercial development of breath tests will need to overcome a number of regulatory, financial and scientific hurdles prior to their acceptance into routine clinical practice. The regulatory agencies (FDA and EMEA) need to adapt and harmonize their approval process for companion diagnostic tests as well as standalone diagnostic breath tests for personalized medicine. The Center for Devices and Radiological Health has deemed any breath test that involves a labeled (13)C substrate/drug and a device requires a Pre Market Approval (PMA), which is analogous to an approved New Drug Application. A PMA is in effect, a private license granted to the applicant for marketing a particular medical device. Any breath test with endogenous VOCs along with a device can be approved via the 510(k) application. A number of (13)C breath tests with clinical applications have been researched recently and results have been published in reputed journals. Diagnostic companies will need to invest the necessary financial resources to develop and get regulatory approval for diagnostic breath tests capable of identifying responders/non responders for FDA approved drugs with narrow therapeutic indices (personalized medicine) or for evaluating the activity of drug metabolizing P450 polymorphic enzymes or for diagnosing diseases at an early stage or for monitoring the efficacy of medications. The financial success of these diagnostic breath tests will then depend entirely on how the test is marketed to

  12. [13C]glucose breath testing provides a noninvasive measure of insulin resistance: calibration analyses against clamp studies.

    PubMed

    Hussain, Maysa; Jangorbhani, Morteza; Schuette, Sally; Considine, Robert V; Chisholm, Robin L; Mather, Kieren J

    2014-02-01

    Exhaled (13)CO2 following ingestion of [(13)C]glucose with a standard oral glucose tolerance load correlates with blood glucose values but is determined by tissue glucose uptake. Therefore exhaled (13)CO2 may also be a surrogate measure of the whole-body glucose disposal rate (GDR) measured by the gold standard hyperinsulinemic euglycemic clamp. Subjects from across the glycemia range were studied on 2 consecutive days under fasting conditions. On Day 1, a 75-g oral glucose load spiked with [(13)C]glucose was administered. On Day 2, a hyperinsulinemic euglycemic clamp was performed. Correlations between breath parameters and clamp-derived GDR were evaluated, and calibration analyses were performed to evaluate the precision of breath parameter predictions of clamp measures. Correlations of breath parameters with GDR and GDR per kilogram of fat-free mass (GDRffm) ranged from 0.54 to 0.61 and 0.54 to 0.66, respectively (all P<0.001). In calibration analyses the root mean square error for breath parameters predicting GDR and GDRffm ranged from 2.32 to 2.46 and from 3.23 to 3.51, respectively. Cross-validation prediction error (CVPE) estimates were 2.35-2.51 (GDR) and 3.29-3.57 (GDRffm). Prediction precision of breath enrichment at 180 min predicting GDR (CVPE=2.35) was superior to that for inverse insulin (2.68) and the Matsuda Index (2.51) but inferior to that for the log of homeostasis model assessment (2.21) and Quantitative Insulin Sensitivity Check Index (2.29) (all P<10(-5)). Similar patterns were seen for predictions of GDRffm. (13)CO2 appearance in exhaled breath following a standard oral glucose load with added [(13)C]glucose provides a valid surrogate index of clamp-derived measures of whole-body insulin resistance, with good accuracy and precision. This noninvasive breath test-based approach can provide a useful measure of whole-body insulin resistance in physiologic and epidemiologic studies.

  13. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing bag test. 84.88 Section 84.88 Public... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a) Breathing bags will be tested in an air atmosphere saturated...

  14. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing bag test. 84.88 Section 84.88 Public... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a) Breathing bags will be tested in an air atmosphere saturated...

  15. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing bag test. 84.88 Section 84.88 Public... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a) Breathing bags will be tested in an air atmosphere saturated...

  16. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  17. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  18. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breath-alcohol test system. 862.3050 Section 862....3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in...

  19. Breath tests: principles, problems, and promise

    SciTech Connect

    Lo, C.W.; Carter, E.A.; Walker, W.A.

    1982-01-01

    Breath tests rely on the measurement of gases produced in the intestine, absorbed, and expired in the breath. Carbohydrates, such as lactose and sucrose, can be administered in ysiologic doses; if malabsorbed, they will be metabolized to hydrogen by colonic bacteria. Since hydrogen is not produced by human metabolic reactions, a rise in breath hydrogen, as measured by gas chromatography, is evidence of carbohydrate malabsorption. Likewise, a rise in breath hydrogen marks the transit time of nonabsorbable carbohydrates such as lactulose through the small intestine into the colon. Simple end-expiratory interval collection into nonsiliconized vacutainer tubes has made these noninvasive tests quite convenient to perform, but various problems, including changes in stool pH intestinal motility, or metabolic rate, may influence results. Another group of breath tests uses substrates labeled with radioactive or stable isotopes of carbon. Labeled fat substrates such as trioctanoin, tripalmitin, and triolein do not produce the expected rise in labeled breath CO/sub 2/ if there is fat malabsorption. Bile acid malabsorption and small intestinal bacterial overgrowth can be measured with labeled cholylglycine or cholyltaurine. Labeled drugs such as aminopyrine, methacetin, and phenacetin can be used as an indication of drug metabolism and liver function. Radioactive substrates have been used to trace metabolic pathways and can be measured by scintillation counters. The availability of nonradioactive stable isotopes has made these ideal for use in children and pregnant women, but the cost of substrates and the mass spectrometers to measure them has so far limited their use to research centers. It is hoped that new techniques of processing and measurement will allow further realization of the exciting potential breath analysis has in a growing list of clinical applications.

  20. Environmental testing of escape breathing apparatus

    SciTech Connect

    Stengel, J W

    1982-05-03

    A new generation of 60-minute self-contained breathing apparatus was being introduced into the underground coal mining industry for use as respiratory protection during fires and mine disasters. Little field experience existed from which to predict the survivability of this new life-support equipment. A series of environmental tests was proposed consisting of exposure to heat, cold, shock, and vibration. Treated and untreated apparatus were evaluated and compared by use on human subjects and a mechanical breathing simulator. Results are reported. After field data have been collected, information may be able to be correlated with environmental testing and used as a predictor of survivability.

  1. 13C-methionine breath tests for mitochondrial liver function assessment.

    PubMed

    Candelli, M; Miele, L; Armuzzi, A; Nista, E C; Pignataro, G; Fini, L; Cazzato, I A; Zocco, M A; Bartolozzi, F; Gasbarrini, G; Grieco, A; Gasbarrini, A

    2008-01-01

    13C-methionine breath test has been proposed as a non-invasive tool for the assessment of human hepatic mithocondrial function. Two methionine breath labeled with 13C in differents point of his molecular structure have been used for breath test analisys. Aim of this study was to compare two differently 13C-labeled methionines in the evaluation of mitochondrial oxidation in basal conditions and after an acute oxidative stress. 15 healthy male subjects (mean age 30.5 +/- 3.1) received [methyl-13C]-methionine dissolved in water. Breath samples were taken at baseline and and 10, 20, 30, 45, 60, 75, 90, 105 and 120 minutes after the ingestion of the labeled substrate. Forthy-eight hours later, subjects underwent the same test 30 minutes after ethanol ingestion (0,3 g/kg of body weight). Seven-day later, subjects underwent breath test using (L-methionine-1-13COOH) as substrate, in basal condition and after ethanol ingestion. At basal condition, the cumulative percentage of 13CO2 recovered in breath during the test period (%cum-dose) was higher using L-methionine-1-13COOH than [methyl-13C]-methionine (10.25 +/- 1.0 vs 4.07 +/- 0.8; p < 0.01). After ethanol ingestion, % cum dose was significantly decreased at 60 and 120 minutes with both methionines (120 min: 10.25 +/- 1.0 vs 5.03% +/- 1.8; < 0.01 and 4.07 +/- 0.8 vs 2.16% +/- 0.9; p < 0.01, respectively). However, %cum-dose during L-methionine-1-13C-breath test was significantly lower than that observed during methyl-13C-methionine breath test (120 minutes: 5.03% +/- 1.8 vs 2.16% +/- 0.9; p < 0.01). In conclusion, breath test based on L-methionine-1-13COOH seems to show a greater reliability when compared to [methyl-13C]-methionine to assess mitochondrial function because a larger amount of labeled carbon that reaches the Krebs' cicle.

  2. Use of the Biphasic (13)C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders.

    PubMed

    Opekun, Antone R; Balesh, Albert M; Shelby, Harold T

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase (13)C-sucrose/(13)C-glucose breath test ((13)C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When (13)C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to (13)CO2 is a proportional indicator of sucrase activity. Subsequently, (13)C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). (13)CO2 enrichment recovery ratio from (13)C-sucrose and secondary (13)C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, (13)C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing (13)CO2-breath enrichment with plasma (13)C-glucose enrichment. (13)C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. (13)CO2-breath enrichment correlated with the appearance of (13)C-sucrose-derived glucose in plasma (r (2) = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60', 0.92 at 75', and 0.96 at mean 60'-75' with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60', 0.77 at 75', and 0.76 at mean 60'-75' (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD.

  3. Use of the Biphasic 13C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders

    PubMed Central

    Balesh, Albert M.; Shelby, Harold T.

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase 13C-sucrose/13C-glucose breath test (13C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When 13C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to 13CO2 is a proportional indicator of sucrase activity. Subsequently, 13C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). 13CO2 enrichment recovery ratio from 13C-sucrose and secondary 13C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, 13C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing 13CO2-breath enrichment with plasma 13C-glucose enrichment. 13C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. 13CO2-breath enrichment correlated with the appearance of 13C-sucrose-derived glucose in plasma (r 2 = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60′, 0.92 at 75′, and 0.96 at mean 60′–75′ with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60′, 0.77 at 75′, and 0.76 at mean 60′–75′ (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD. PMID:27579322

  4. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  5. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  6. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  7. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breath-alcohol test system. 862.3050 Section 862...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862.3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened...

  8. 21 CFR 862.3050 - Breath-alcohol test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath-alcohol test system. 862.3050 Section 862...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862.3050 Breath-alcohol test system. (a) Identification. A breath-alcohol test system is a device intened...

  9. Breath tests and irritable bowel syndrome

    PubMed Central

    Rana, Satya Vati; Malik, Aastha

    2014-01-01

    Breath tests are non-invasive tests and can detect H2 and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients. PMID:24976698

  10. Breath tests and irritable bowel syndrome.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-06-28

    Breath tests are non-invasive tests and can detect H₂ and CH₄ gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath. These tests are used in the diagnosis of carbohydrate malabsorption, small intestinal bacterial overgrowth, and for measuring the orocecal transit time. Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome (IBS)-type symptoms such as diarrhea and/or constipation, bloating, excess flatulence, headaches and lack of energy. Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life. It may reflect dietary imbalance, such as excess fiber intake, or may be a manifestation of IBS. However, bloating may also represent small intestinal bacterial overgrowth. Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H₂ breath testing to determine the presence or absence of bacterial overgrowth. If bacterial overgrowth is identified, patients are typically treated with antibiotics. Evaluation of IBS generally includes testing of other disorders that cause similar symptoms. Carbohydrate malabsorption (lactose, fructose, sorbitol) can cause abdominal fullness, bloating, nausea, abdominal pain, flatulence, and diarrhea, which are similar to the symptoms of IBS. However, it is unclear if these digestive disorders contribute to or cause the symptoms of IBS. Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS. Thus, diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients.

  11. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  12. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  13. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  14. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  15. 42 CFR 84.152 - Breathing tube test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing tube test; minimum requirements. 84.152... Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from...

  16. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  17. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  18. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  19. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  20. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  1. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  2. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  3. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  4. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation... continuous rate of 85 liters per minute. (b) The exhalation resistance of demand apparatus shall not...

  5. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation... continuous rate of 85 liters per minute. (b) The exhalation resistance of demand apparatus shall not...

  6. Using the noninvasive (13)C-sucrose breath test to measure intestinal sucrase activity in swine.

    PubMed

    Terry, Robyn; van Wettere, William H E J; Whittaker, Alexandra L; Herde, Paul J; Howarth, Gordon S

    2012-12-01

    The sucrose breath test (SBT) is a simple noninvasive technique used currently to determine intestinal absorptive function in humans and rodents. However, to date, the test has not been adapted for use in swine. During weaning, intestinal sucrase activity in piglets temporarily declines in response to stressors and is commonly used as a marker of the intestinal response to weaning. Here we assessed the sucrose dose needed for using the SBT in piglets. Six randomly allocated piglets were orogastrically gavaged with (13)C-labeled sucrose at a dose of 2 g/kg; breath samples were collected for measurement of (13)CO2 on days 0 (approximately 17 h after weaning), 5, and 10 after weaning. The resultant SBT value (cumulative dose at 90 min) was decreased by 46% on day 5 after weaning relative to baseline levels, consistent with temporal changes in gastrointestinal sucrase activity associated with weaning. We conclude that a sucrose dose of 2 g/kg is satisfactory to conduct SBT studies in piglets. With further development, the SBT may provide a new tool to noninvasively monitor digestive function in weaned piglets, to assess the effects of nutritional strategies on intestinal health, and as an indicator of gut integrity and function in swine models of human gastrointestinal disease.

  7. Using the Noninvasive 13C-Sucrose Breath Test to Measure Intestinal Sucrase Activity in Swine

    PubMed Central

    Terry, Robyn; van Wettere, William HEJ; Whittaker, Alexandra L; Herde, Paul J; Howarth, Gordon S

    2012-01-01

    The sucrose breath test (SBT) is a simple noninvasive technique used currently to determine intestinal absorptive function in humans and rodents. However, to date, the test has not been adapted for use in swine. During weaning, intestinal sucrase activity in piglets temporarily declines in response to stressors and is commonly used as a marker of the intestinal response to weaning. Here we assessed the sucrose dose needed for using the SBT in piglets. Six randomly allocated piglets were orogastrically gavaged with 13C-labeled sucrose at a dose of 2 g/kg; breath samples were collected for measurement of 13CO2 on days 0 (approximately 17 h after weaning), 5, and 10 after weaning. The resultant SBT value (cumulative dose at 90 min) was decreased by 46% on day 5 after weaning relative to baseline levels, consistent with temporal changes in gastrointestinal sucrase activity associated with weaning. We conclude that a sucrose dose of 2 g/kg is satisfactory to conduct SBT studies in piglets. With further development, the SBT may provide a new tool to noninvasively monitor digestive function in weaned piglets, to assess the effects of nutritional strategies on intestinal health, and as an indicator of gut integrity and function in swine models of human gastrointestinal disease. PMID:23561884

  8. Probiotic effects on 5-fluorouracil-induced mucositis assessed by the sucrose breath test in rats.

    PubMed

    Mauger, Chad A; Butler, Ross N; Geier, Mark S; Tooley, Katie L; Howarth, Gordon S

    2007-03-01

    The sucrose breath test (SBT) was employed to noninvasively assess the efficacy of probiotics in 5-fluorouracil (5-FU)-induced intestinal mucositis. Dark Agouti rats were allocated to 5 groups (n = 10): 5-FU + L. fermentum BR 11, 5-FU + L. rhamnosus GG, 5-FU + B. lactis BB 12, 5-FU + skim milk (SM), and saline + SM. Probiotics were administered by oral gavage for 10 days. Mucositis was induced on day 7 by intraperitoneal injection of 5-FU (150 mg/kg) or vehicle (saline). Rats were sacrificed 72 h after 5-FU injection. The SBT measured breath 13CO2 (expressed as percentage cumulative dose at 90 min; %CD90) on days 0, 7, and 10. %CD90 was significantly lower in 5-FU-treated controls compared with that in saline-treated controls on day 10. 5-FU caused an 83% reduction in sucrase and a 510% increase in MPO activity. The SBT detected damage induced by 5-FU and is a simple, noninvasive indicator of small bowel injury. The probiotics assessed offered no protection from mucositis at the dose tested.

  9. Air-breathing Rocket Engine Test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This Quick Time movie depicts the Rocketdyne static test of an air-breathing rocket. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's advanced Transportation Program at the Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  10. Biosynthesis of Nudicaulins: A (13) CO2 -pulse/chase labeling study with Papaver nudicaule.

    PubMed

    Tatsis, Evangelos C; Eylert, Eva; Maddula, Ravi Kumar; Ostrozhenkova, Elena; Svatoš, Aleš; Eisenreich, Wolfgang; Schneider, Bernd

    2014-07-21

    Nudicaulins are unique alkaloids responsible for the yellow color of the petals of some papaveraceaous plants. To elucidate the unknown biosynthetic origin of the skeleton, a (13) CO2 -pulse/chase experiment was performed with growing Papaver nudicaule plants. (13) C NMR analysis revealed more than 20 multiple (13) C-enriched isotopologues in nudicaulins from the petals of (13) CO2 -labeled plants. The complex labeling pattern was compared with the isotopologue composition of a kaempferol derivative that was isolated from petals of the same (13) CO2 -labeled plants. The deconvolution of the labeling profiles indicated that the nudicaulin scaffold is assembled from products or intermediates of indole metabolism, the phenylpropanoid pathway, and the polyketide biosynthesis. Naringenin-type compounds and tryptophan/tryptamine are potential substrates for the condensation reaction finally generating the aglycone skeleton of nudicaulins.

  11. Investigation of Metabolism of Exogenous Glucose at the Early Stage and Onset of Diabetes Mellitus in Otsuka Long-Evans Tokushima Fatty Rats Using [1, 2, 3-13C]Glucose Breath Tests

    PubMed Central

    Kijima, Sho; Tanaka, Hideki

    2016-01-01

    This study aimed to evaluate changes in glucose metabolism at the early stage and onset of diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Specifically, after the oral administration of [1, 2, 3-13C]glucose, the levels of exhaled 13CO2, which most likely originated from pyruvate decarboxylation and tricarboxylic acid, were measured. Eight OLETF rats and eight control rats (Long-Evans Tokushima Otsuka [LETO]) were administered 13C-glucose. Three types of 13C-glucose breath tests were performed thrice in each period at 2-week intervals. [3-13C]glucose results in a 13C isotope at position 1 in the pyruvate molecule, which provides 13CO2. The 13C at carbons 1 and 2 of glucose is converted to 13C at carbons 2 and 1 of acetate, respectively, which produce 13CO2. Based on metabolic differences of the labeled sites, glucose metabolism was evaluated using the results of three breath tests. The increase in 13CO2 excretion in OLETF rats was delayed in all three breath tests compared to that in control rats, suggesting that OLETF rats had a lower glucose metabolism than control rats. In addition, overall glucose metabolism increased with age in both groups. The utilization of [2-13C]glucose was suppressed in OLETF rats at 6–12 weeks of age, but they showed higher [3-13C]glucose oxidation than control rats at 22–25 weeks of age. In the [1-13C]glucose breath test, no significant differences in the area under the curve until 180 minutes (AUC180) were observed between OLETF and LETO rats of any age. Glucose metabolism kinetics were different between the age groups and two groups of rats; however, these differences were not significant based on the overall AUC180 of [1-13C]glucose. We conclude that breath 13CO2 excretion is reduced in OLETF rats at the primary stage of prediabetes, indicating differences in glucose oxidation kinetics between OLETF and LETO rats. PMID:27483133

  12. Investigation of Metabolism of Exogenous Glucose at the Early Stage and Onset of Diabetes Mellitus in Otsuka Long-Evans Tokushima Fatty Rats Using [1, 2, 3-13C]Glucose Breath Tests.

    PubMed

    Kawagoe, Naoyuki; Kano, Osamu; Kijima, Sho; Tanaka, Hideki; Takayanagi, Masaaki; Urita, Yoshihisa

    2016-01-01

    This study aimed to evaluate changes in glucose metabolism at the early stage and onset of diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Specifically, after the oral administration of [1, 2, 3-13C]glucose, the levels of exhaled 13CO2, which most likely originated from pyruvate decarboxylation and tricarboxylic acid, were measured. Eight OLETF rats and eight control rats (Long-Evans Tokushima Otsuka [LETO]) were administered 13C-glucose. Three types of 13C-glucose breath tests were performed thrice in each period at 2-week intervals. [3-13C]glucose results in a 13C isotope at position 1 in the pyruvate molecule, which provides 13CO2. The 13C at carbons 1 and 2 of glucose is converted to 13C at carbons 2 and 1 of acetate, respectively, which produce 13CO2. Based on metabolic differences of the labeled sites, glucose metabolism was evaluated using the results of three breath tests. The increase in 13CO2 excretion in OLETF rats was delayed in all three breath tests compared to that in control rats, suggesting that OLETF rats had a lower glucose metabolism than control rats. In addition, overall glucose metabolism increased with age in both groups. The utilization of [2-13C]glucose was suppressed in OLETF rats at 6-12 weeks of age, but they showed higher [3-13C]glucose oxidation than control rats at 22-25 weeks of age. In the [1-13C]glucose breath test, no significant differences in the area under the curve until 180 minutes (AUC180) were observed between OLETF and LETO rats of any age. Glucose metabolism kinetics were different between the age groups and two groups of rats; however, these differences were not significant based on the overall AUC180 of [1-13C]glucose. We conclude that breath 13CO2 excretion is reduced in OLETF rats at the primary stage of prediabetes, indicating differences in glucose oxidation kinetics between OLETF and LETO rats.

  13. Air-Breathing Rocket Engine Test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This photograph depicts an air-breathing rocket engine that completed an hour or 3,600 seconds of testing at the General Applied Sciences Laboratory in Ronkonkoma, New York. Referred to as ARGO by its design team, the engine is named after the mythological Greek ship that bore Jason and the Argonauts on their epic voyage of discovery. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced SpaceTransportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  14. Air-Breathing Rocket Engine Test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This photograph depicts an air-breathing rocket engine that completed an hour or 3,600 seconds of testing at the General Applied Sciences Laboratory in Ronkonkoma, New York. Referred to as ARGO by its design team, the engine is named after the mythological Greek ship that bore Jason and the Argonauts on their epic voyage of discovery. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced SpaceTransportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  15. Drinking and driving: success of random breath testing in Finland.

    PubMed Central

    Dunbar, J A; Penttila, A; Pikkarainen, J

    1987-01-01

    Since the introduction of random breath testing in Finland in 1977 the drinking and driving rate has halved, and there has been an appreciable reduction in the rates of death and injury from road accidents associated with drinking. The results of Finnish studies indicate that random breath testing deters social drinkers and detects problem drinkers. Problem drinkers are more likely to be driving in morning traffic, when vulnerable road users such as children are about, and are more likely to be detected by random breath testing than by any other police activity. Random breath testing is a popular measure and has not only saved lives but has paid for itself by savings in health service and other resources. Introducing random breath testing into Britain could save at least 400 lives a year. The main recommendation of the Blennerhassett report of 1976--discretionary testing--is compared with the success of random breath testing in Finland. Images FIG 1 PMID:3113620

  16. Monitoring breath during oral glucose tolerance tests.

    PubMed

    Ghimenti, S; Tabucchi, S; Lomonaco, T; Di Francesco, F; Fuoco, R; Onor, M; Lenzi, S; Trivella, M G

    2013-03-01

    The evolution of breath composition during oral glucose tolerance tests (OGTTs) was analysed by thermal desorption/gas chromatography/mass spectrometry in 16 subjects and correlated to blood glucose levels. The glucose tolerance tests classified five of the subjects as diabetics, eight as affected by impaired glucose tolerance and three as normoglycaemic. Acetone levels were generally higher in diabetics (average concentration values: diabetics, 300 ± 40 ppbv; impaired glucose tolerance, 350 ± 30 ppbv; normoglycaemic, 230 ± 20 ppbv) but the large inter-individual variability did not allow us to identify the three groups by this parameter alone. The exhalation of 3-hydroxy-butan-2-one and butane-2,3-dione, likely due to the metabolization of glucose by bacteria in the mouth, was also observed. Future work will involve the extension of the analyses to other volatile compounds by attempting to improve the level of discrimination between the various classes of subjects.

  17. New ice core records on the glacial/interglacial change in atmospheric δ13CO2

    NASA Astrophysics Data System (ADS)

    Fischer, H.; Schmitt, J.; Schneider, R.; Elsig, J.; Lourantou, A.; Leuenberger, M.; Stocker, T. F.; Koehler, P.; Lavric, J.; Raynaud, D. P.; Chappellaz, J. A.

    2010-12-01

    The reconstruction of δ13CO2 using Antarctic ice cores promises a deeper understanding on the causes of past atmospheric CO2 changes. Previous measurements on the Taylor Dome ice core over the last 30,000 years (Smith et al., 1999) indicated marine processes to be dominating the significant δ13CO2 changes over the transition, whereas glacial δ13CO2 was only slightly depleted relative to the Holocene (Leuenberger et al., 1992; Smith et al., 1999). However, significant uncertainty and the low temporal resolution of the Taylor Dome δ13CO2 data prevented a more detailed interpretation. Recently, substantial improvements have been made in the analysis and the resolution of ice core δ13CO2 records (Elsig et al., 2009; Lourantou et al., 2010). With these and new measurements presented here, three independent δ13CO2 data sets over the last glacial/interglacial transition have now been derived from the two EPICA and the Talos Dome ice cores. Two of the methods use traditional dry extraction techniques with a reproducibility of 0.07-0.1‰. The third method uses a novel sublimation technique with a reproducibility of 0.05‰. Here we compare the data sets, their analytical setups and discuss their joint information as well as their differences. The three records provide a more detailed picture on the temporal evolution of δ13CO2 and confirm two pronounced isotope minima between 18-12,000 years BP in parallel to the two major phases of CO2 increase (Lourantou et al., 2010; Smith et al., 1999) as also reflected in marine sediments (Marchitto et al., 2007; Skinner et al., 2010). Accordingly, a release of old carbon from the deep ocean is most likely responsible for a large part of the long-term increase in atmospheric CO2 in this time interval. However, the fast CO2 jumps at a round 12,000 and 14,000 years BP may be partly of terrestrial origin (Elsig, 2009; Köhler et al., 2010b). The new sublimation data set provides also unambiguous δ13CO2 data for clathrate ice in

  18. 13C-breath tests for sucrose digestion in congenital sucrase isomaltase-deficient and sacrosidase-supplemented patients.

    PubMed

    Robayo-Torres, Claudia C; Opekun, Antone R; Quezada-Calvillo, Roberto; Villa, Xavier; Smith, E O; Navarrete, Marilyn; Baker, Susan S; Nichols, Buford L

    2009-04-01

    Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is useful, but is not specific for confirmation of CSID. We investigated a more specific 13C-sucrose labeled BT. Determine whether CSID can be detected with the 13C-sucrose BT without duodenal biopsy sucrase assay, and if the 13C-sucrose BT can document restoration of sucrose digestion by CSID patients after oral supplementation with sacrosidase (Sucraid). Ten CSID patients were diagnosed by low biopsy sucrase activity. Ten controls were children who underwent endoscopy and biopsy because of dyspepsia or chronic diarrhea with normal mucosal enzymes activity and histology. Uniformly labeled 13C-glucose and 13C-sucrose loads were orally administered. 13CO2 breath enrichments were assayed using an infrared spectrophotometer. In CSID patients, the 13C-sucrose load was repeated adding Sucraid. Sucrose digestion and oxidation were calculated as a mean percent coefficient of glucose oxidation averaged between 30 and 90 minutes. Classification of patients by 13C-sucrose BT percent coefficient of glucose oxidation agreed with biopsy sucrase activity. The breath test also documented the return to normal of sucrose digestion and oxidation after supplementation of CSID patients with Sucraid. 13C-sucrose BT is an accurate and specific noninvasive confirmatory test for CSID and for enzyme replacement management.

  19. 13C-sodium acetate breath test for evaluation of gastric emptying times in dogs with gastric dilatation-volvulus.

    PubMed

    Schmitz, S; Jansen, N; Failing, K; Neiger, R

    2013-01-01

    The aim of the study was to assess solid phase gastric emptying via non-invasive 13C-sodium acetate breath test in large breed dogs with or without gastric dilatation-volvulus (GDV). Dogs were recruited into one of the following groups: group 1 = healthy large breed dogs with no history of GDV, group 2 = dogs that underwent elective abdominal surgery for reasons unrelated to the gastrointestinal tract, and group 3 = dogs that underwent laparotomy and gastropexy to correct GDV. The dogs were fed a test meal containing 100 mg 13C-sodium acetate (for group 2 and 3, this was < 48 hours post-operatively). Breath samples were obtained at baseline and every 30 minutes for 3 hours, then every hour for a total of 7 hours. 12CO2/13CO2 ratio was measured for each breath sample via non-dispersive infrared spectroscopy and 25%, 50% and 75% gastric emptying times were calculated and compared between groups. Gastric emptying times were significantly prolonged in dogs undergoing surgery (group 2) compared to group 1 and 3. Also, gastric emptying times of dogs with GDV were significantly prolonged compared to controls, but not to the same extent as dogs in group 2. There was a significant effect of abdominal surgery on gastric emptying times. Surprisingly, dogs after GDV surgery and gastropexy had shorter gastric emptying times than dogs undergoing laparotomy for reasons other than GDV, but still prolonged compared to healthy controls. The reason for these differences requires further study.

  20. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  1. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  2. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  3. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... resistance requirements for chemical cartridge respirators are as follows: Maximum Resistance Type...

  4. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... resistance requirements for chemical cartridge respirators are as follows: Maximum Resistance Type...

  5. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... rate of 85 liters per minute. (b) The maximum allowable resistance requirements for gas masks are...

  6. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... rate of 85 liters per minute. (b) The maximum allowable resistance requirements for gas masks are...

  7. Breath hydrogen test after oral lactose in postgastrectomy patients.

    PubMed

    Welsh, J D; Griffiths, W J

    1980-11-01

    The purpose of this study was to compare breath hydrogen tests after oral lactose ingestion in nonoperated subjects and postgastrectomy patients. Simultaneous oral lactose tolerance tests and breath hydrogen tests were performed in 50 subjects. Twenty of the 30 subjects without prior gastric surgery had normal lactase activities and low breath hydrogen concentrations. The other 10 subjects had low lactase levels and increased breath hydrogen concentrations. The remaining 20 subjects had prior gastric surgery. Seven of these had normal lactase activities, no history of milk intolerance and low breath hydrogen concentrations. Two of the postgastrectomy patients had low intestinal lactases, milk intolerance, and high breath hydrogens. The remaining 11 postgastrectomy patients had normal intestinal lactases but high breath hydrogens. Eight of the 11 had milk intolerance while two of the other three had not consumed milk since childhood. From these studies the following conclusions can be reached: 1)a low lactose breath hydrogen test in the postgastrectomy subject correctly identifies the individual with normal lactase activity. However, high breath hydrogen responses, may be found in either those with lactase deficiency or normal lactase activity. 2) Lactose malabsorption would appear to explain the milk intolerance in the postgastrectomy patient with normal lactase activity.

  8. Breath testing and personal exposure--SIFT-MS detection of breath acetonitrile for exposure monitoring.

    PubMed

    Storer, Malina; Curry, Kirsty; Squire, Marie; Kingham, Simon; Epton, Michael

    2015-05-26

    Breath testing has potential for the rapid assessment of the source and impact of exposure to air pollutants. During the development of a breath test for acetonitrile using selected ion flow tube mass spectrometry (SIFT-MS) raised acetonitrile concentrations in the breath of volunteers were observed that could not be explained by known sources of exposure. Workplace/laboratory exposure to acetonitrile was proposed since this was common to the volunteers with increased breath concentrations. SIFT-MS measurements of acetonitrile in breath and air were used to confirm that an academic chemistry laboratory was the source of exposure to acetonitrile, and quantify the changes that occurred to exhaled acetonitrile after exposure. High concentrations of acetonitrile were detected in the air of the chemistry laboratory. However, concentrations in the offices were not significantly different across the campus. There was a significant difference in the exhaled acetonitrile concentrations of people who worked in the chemistry laboratories (exposed) and those who did not (non-exposed). SIFT-MS testing of air and breath made it possible to determine that occupational exposure to acetonitrile in the chemistry laboratory was the cause of increased exhaled acetonitrile. Additionally, the sensitivity was adequate to measure the changes to exhaled amounts and found that breath concentrations increased quickly with short exposure and remained increased even after periods of non-exposure. There is potential to add acetonitrile to a suite of VOCs to investigate source and impact of poor air quality.

  9. Influence of different proton pump inhibitors on activity of cytochrome P450 assessed by [(13)C]-aminopyrine breath test.

    PubMed

    Kodaira, Chise; Uchida, Shinya; Yamade, Mihoko; Nishino, Masafumi; Ikuma, Mutsuhiro; Namiki, Noriyuki; Sugimoto, Mitsushige; Watanabe, Hiroshi; Hishida, Akira; Furuta, Takahisa

    2012-03-01

    Aminopyrine is metabolized by cytochrome P450 (CYP) in the liver. The investigators evaluated influences of different PPIs on CYP activity as assessed by the [(13)C]-aminopyrine breath test ([(13)C]-ABT). Subjects were 15 healthy volunteers with different CYP2C19 status (5 rapid metabolizers [RMs], 5 intermediate metabolizers [IMs], and 5 poor metabolizers [PMs]). Breath samples were collected before and every 15 to 30 minutes for 3 hours after oral ingestion of [(13)C]-aminopyrine 100 mg on day 8 of each of the following regimens: control; omeprazole 20 mg and 80 mg, lansoprazole 30 mg, and rabeprazole 20 mg. Changes in carbon isotope ratios in carbon dioxide ((13)CO(2)/(12)CO(2)) in breath samples were measured by infrared spectrometry and expressed as delta-over-baseline (DOB) ratios (‰). Mean areas under the curve of DOB from 0 to 3 h (AUC(0-3h) of DOB) were significantly decreased by omeprazole 20 mg and lansoprazole 30 mg but not by rabeprazole 20 mg. Conversely, higher PPI dose (ie, omeprazole 80 mg) seemed to further decrease AUC(0-3h) of DOB in RMs but increased it in PMs. Omeprazole and lansoprazole at the standard doses inhibit CYP activity but rabeprazole does not, whereas high-dose omeprazole seems to induce CYPs.

  10. Chronic alcohol overconsumption may alter gut microbial metabolism: a retrospective study of 719 13C-D-xylose breath test results

    PubMed Central

    Bjørkhaug, Steinar Traae; Skar, Viggo; Medhus, Asle W.; Tollisen, Anita; Bramness, Jørgen G.; Valeur, Jørgen

    2017-01-01

    ABSTRACT Objective: Alterations of gut microbiota composition or function may participate in the pathophysiology of several diseases. We aimed to explore the effect of chronic alcohol overconsumption on gut microbial metabolism, as assessed by evaluating 13C-D-xylose breath test results. Materials and methods: We investigated all 13C-D-xylose breath tests performed at Lovisenberg Diaconal Hospital during the years 2005 to 2011, using patient files for diagnosing the patients into one of three patient categories: alcohol overconsumption, coeliac disease and functional bowel disorder. In addition, a group of healthy controls was included. The time curves of 13CO2 excretion in breath samples were divided into two phases, evaluating small intestinal absorption (0–60 min) and colonic microbial metabolism (90–240 min), respectively. Results: A total of 719 patients underwent 13C-D-xylose breath testing during the inclusion period. Thirty-five had a history of alcohol overconsumption, 66 had coeliac disease, and 216 had a functional bowel disorder, while 44 healthy controls were included for comparison. The alcohol overconsumption group had similar small intestinal phase results as the group of patients with untreated coeliac disease. During the colonic phase, the group of patients with alcohol overconsumption differed from all the other groups in terms of 13C-xylose recovery, with significantly less 13CO2 excretion compared to the other groups. Conclusion: The results suggest that patients with a history of alcohol overconsumption suffer from both small intestinal malabsorption and impaired colonic microbial metabolism. The role of gut microbiota in chronic alcohol overconsumption should be investigated further. PMID:28572752

  11. Chronic alcohol overconsumption may alter gut microbial metabolism: a retrospective study of 719 (13)C-D-xylose breath test results.

    PubMed

    Bjørkhaug, Steinar Traae; Skar, Viggo; Medhus, Asle W; Tollisen, Anita; Bramness, Jørgen G; Valeur, Jørgen

    2017-01-01

    Objective: Alterations of gut microbiota composition or function may participate in the pathophysiology of several diseases. We aimed to explore the effect of chronic alcohol overconsumption on gut microbial metabolism, as assessed by evaluating (13)C-D-xylose breath test results. Materials and methods: We investigated all (13)C-D-xylose breath tests performed at Lovisenberg Diaconal Hospital during the years 2005 to 2011, using patient files for diagnosing the patients into one of three patient categories: alcohol overconsumption, coeliac disease and functional bowel disorder. In addition, a group of healthy controls was included. The time curves of (13)CO2 excretion in breath samples were divided into two phases, evaluating small intestinal absorption (0-60 min) and colonic microbial metabolism (90-240 min), respectively. Results: A total of 719 patients underwent (13)C-D-xylose breath testing during the inclusion period. Thirty-five had a history of alcohol overconsumption, 66 had coeliac disease, and 216 had a functional bowel disorder, while 44 healthy controls were included for comparison. The alcohol overconsumption group had similar small intestinal phase results as the group of patients with untreated coeliac disease. During the colonic phase, the group of patients with alcohol overconsumption differed from all the other groups in terms of (13)C-xylose recovery, with significantly less (13)CO2 excretion compared to the other groups. Conclusion: The results suggest that patients with a history of alcohol overconsumption suffer from both small intestinal malabsorption and impaired colonic microbial metabolism. The role of gut microbiota in chronic alcohol overconsumption should be investigated further.

  12. The Influence of Age on Interaction between Breath-Holding Test and Single-Breath Carbon Dioxide Test

    PubMed Central

    Zabolotskikh, Igor

    2017-01-01

    Introduction. The aim of the study was to compare the breath-holding test and single-breath carbon dioxide test in evaluation of the peripheral chemoreflex sensitivity to carbon dioxide in healthy subjects of different age. Methods. The study involved 47 healthy volunteers between ages of 25 and 85 years. All participants were divided into 4 groups according to age: 25 to 44 years (n = 14), 45 to 60 years (n = 13), 60 to 75 years (n = 12), and older than 75 years (n = 8). Breath-holding test was performed in the morning before breakfast. The single-breath carbon dioxide (SB-CO2) test was performed the following day. Results. No correlation was found between age and duration of breath-holding (r = 0.13) and between age and peripheral chemoreflex sensitivity to CO2 (r = 0.07). In all age groups there were no significant differences in the mean values from the breath-holding test and peripheral chemoreflex sensitivity tests. In all groups there was a strong significant inverse correlation between breath-holding test and SB-CO2 test. Conclusion. A breath-holding test reflects the sensitivity of the peripheral chemoreflex to carbon dioxide in healthy elderly humans. Increasing age alone does not alter the peripheral ventilatory response to hypercapnia. PMID:28251147

  13. The Influence of Age on Interaction between Breath-Holding Test and Single-Breath Carbon Dioxide Test.

    PubMed

    Trembach, Nikita; Zabolotskikh, Igor

    2017-01-01

    Introduction. The aim of the study was to compare the breath-holding test and single-breath carbon dioxide test in evaluation of the peripheral chemoreflex sensitivity to carbon dioxide in healthy subjects of different age. Methods. The study involved 47 healthy volunteers between ages of 25 and 85 years. All participants were divided into 4 groups according to age: 25 to 44 years (n = 14), 45 to 60 years (n = 13), 60 to 75 years (n = 12), and older than 75 years (n = 8). Breath-holding test was performed in the morning before breakfast. The single-breath carbon dioxide (SB-CO2) test was performed the following day. Results. No correlation was found between age and duration of breath-holding (r = 0.13) and between age and peripheral chemoreflex sensitivity to CO2 (r = 0.07). In all age groups there were no significant differences in the mean values from the breath-holding test and peripheral chemoreflex sensitivity tests. In all groups there was a strong significant inverse correlation between breath-holding test and SB-CO2 test. Conclusion. A breath-holding test reflects the sensitivity of the peripheral chemoreflex to carbon dioxide in healthy elderly humans. Increasing age alone does not alter the peripheral ventilatory response to hypercapnia.

  14. 13CO2 as a universal metabolic tracer in isotopologue perturbation experiments.

    PubMed

    Römisch-Margl, Werner; Schramek, Nicholas; Radykewicz, Tanja; Ettenhuber, Christian; Eylert, Eva; Huber, Claudia; Römisch-Margl, Lilla; Schwarz, Christine; Dobner, Maria; Demmel, Norbert; Winzenhörlein, Bernhard; Bacher, Adelbert; Eisenreich, Wolfgang

    2007-01-01

    A tobacco plant was illuminated for 5h in an atmosphere containing (13)CO(2) and then maintained for 10 days under standard greenhouse conditions. Nicotine, glucose, and amino acids from proteins were isolated chromatographically. Isotopologue abundances of isolated metabolites were determined quantitatively by NMR spectroscopy and mass spectrometry. The observed non-stochastic isotopologue patterns indicate (i) formation of multiply labeled photosynthetic carbohydrates during the (13)CO(2) pulse phase followed by (ii) partial catabolism of the primary photosynthetic products, and (iii) recombination of the (13)C-labeled fragments with unlabeled intermediary metabolites during the chase period. The detected and simulated isotopologue profiles of glucose and amino acids reflect carbon partitioning that is dominated by the Calvin cycle and glycolysis/glucogenesis. Retrobiosynthetic analysis of the nicotine pattern is in line with its known formation from nicotinic acid and putrescine via aspartate, glyceraldehyde phosphate and alpha-ketoglutarate as basic building blocks. The study demonstrates that pulse/chase labeling with (13)CO(2) as precursor is a powerful tool for the analysis of quantitative aspects of plant metabolism in completely unperturbed whole plants.

  15. Discriminating and continuous measurement of photosynthesis and respiration by monitoring 13CO2 and 12CO2 as tracers.

    PubMed

    Nishi, I; Futami, J; Ma, P; Ishii, H; Takakura, T; Goto, E

    1996-12-01

    The simultaneous and discriminative measurement of the photosynthesis and the respiration of the plant was attained by simultaneous monitoring of 13CO2 and 12CO2 by artificial control of 13CO2 abundance of ambient air. The principle of the measurement is based on the following physiological processes. 6CO2 + 12H2O --> C6H12O6 + 6O2 + 6H2O, 6(13C)O2 + 12H2O --> (13C6)H12O6 + 6O2 + 6H2O, 6CO2 + 12H2(18O) --> C6H12O6 + 6(18O)18O + 6H20. Assuming that respiratory consumption of the new born carbon substrate fixed by photosynthesis is negligible during the measurement, the photosynthetic CO2 consumption VPCO2 and the respiratory CO2 production VRCO2 are measured according to the estimation (1) or (2), (1) for closed method, VPCO2 = k(V0 - V t)¿ F13CO2 + (F12CO2/F13CO2)F13CO2 ¿, VRCO2 = k(V0 - V t)¿ F12CO2 - (F12CO2/F13CO2)F13CO2 ¿, (2) for open method, VPCO2 = kVE ¿ (FI13CO2 - FE13CO2) + (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿, VRCO2 = kVE ¿ (FI12CO2 - FE12CO2) - (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿ where V0 is initial volume of growth chamber including attached flexible bag, FICO2 is the inlet or initial gas concentration of CO2 and FECO2 is the ambient gas concentration of CO2 in the chamber, V and VE are the sampling rate of mass spectrometer and the ventilation rate of the growth chamber respectively, k is the STPD conversion factor = ¿273(PB-PH2O)/760(273+tE)¿, tE(degrees C) is the ambient gas temperature. In the closed method, the gas container of the growth chamber is circulated, resulting FECO2 is varied according to the balance of consumption and production of CO2, while in the open method VE is controlled to keep FECO2 at a constant value. Both (1) and (2) methods were examined and evaluated on the measurements of komatsuna and maize.

  16. Precise measurements of the total concentration of atmospheric CO2 and 13CO2/12CO2 isotopic ratio using a lead-salt laser diode spectrometer.

    PubMed

    Croizé, Laurence; Mondelain, Didier; Camy-Peyret, Claude; Delmotte, Marc; Schmidt, Martina

    2008-04-01

    We have developed a tunable diode laser spectrometer, called SIMCO (spectrometer for isotopic measurements of CO(2)), for determining the concentrations of (12)CO(2) and (13)CO(2) in atmospheric air, from which the total concentration of CO(2) and the isotopic composition (expressed in delta units) delta(13)CO(2) are calculated. The two concentrations are measured using a pair of lines around 2290.1 cm(-1), by fitting a line profile model, taking into account the confinement narrowing effect to achieve a better accuracy. Using the Allan variance, we have demonstrated (for an integration time of 25 s) a precision of 0.1 ppmv for the total CO(2) concentration and of 0.3[per thousand] for delta(13)CO(2). The performances on atmospheric air have been tested during a 3 days campaign by comparing the SIMCO instrument with a gas chromatograph (GC) for the measurement of the total CO(2) concentration and with an isotopic ratio mass spectrometer (MS) for the isotopic composition. The CO(2) concentration measurements of SIMCO are in very good agreement with the GC data with a mean difference of Delta(CO(2))=0.16+/-1.20 ppmv for a comparison period of 45 h and the linearity of the concentration between the two instruments is also very good (slope of correlation: 0.9996+/-0.0003) over the range between 380 and 415 ppmv. For delta(13)CO(2), the comparison with the MS data shows a larger mean difference of Delta(delta(13)CO(2))=(-1.9+/-1.2)[per thousand], which could be partly related to small residual fluctuations of the overall SIMCO instrument response.

  17. In vivo assessment of the mitochondrial response to caloric restriction in obese women by the 2-keto[1-C]isocaproate breath test.

    PubMed

    Parra, Dolores; González, Alvaro; Martínez, J Alfredo; Labayen, Idoia; Díez, Nieves

    2003-04-01

    The 2-keto[1-(13)C]isocaproate breath test has been proposed as a tool to detect mitochondrial dysfunction in alcoholic liver disease. The aim of this study was to evaluate if the 2-keto[1-(13)C]isocaproate breath test could detect in vivo dynamic changes on mitochondrial activity due to caloric restriction in obese women. Fifteen obese women (body mass index [BMI] > 30 kg/m(2)) participated in the study at baseline. Ten of these women agreed to participate on a diet program to induce body weight loss. Fifteen lean women (BMI < 25 kg/m(2)) were included as a control group. The breath test was performed by the oral administration of the tracer measuring (13)CO(2) enrichment in breath before and after ingestion using isotope ratio mass spectrometry. Body composition, resting energy expenditure, and plasma levels of insulin and leptin were measured. There were no relationships observed between the 2-keto[1-(13)C]isocaproate breath test and the plasma insulin (before diet: P =.863; after diet: P =.879), or leptin (before diet: P =.500; after diet: P =.637). In obese women before treatment, kilograms of fat free mass (P =.108), resting energy expenditure adjusted for body composition (P =.312), and the 2-keto[1-(13)C]isocaproate breath test (P =.205) were similar in comparison to lean women. However, 2-keto[1-(13)C]isocaproate oxidation tended to increase after dieting and was significantly higher than in controls (P =.015). These data suggest that the 2-keto[1-(13)C]isocaproate breath test reflected the adaptive modifications in mitochondrial oxidation in response to caloric restriction in obese women. Copyright 2003 Elsevier, Inc. All rights reserved.

  18. Data Mining Techniques Applied to Hydrogen Lactose Breath Test.

    PubMed

    Rubio-Escudero, Cristina; Valverde-Fernández, Justo; Nepomuceno-Chamorro, Isabel; Pontes-Balanza, Beatriz; Hernández-Mendoza, Yoedusvany; Rodríguez-Herrera, Alfonso

    2017-01-01

    Analyze a set of data of hydrogen breath tests by use of data mining tools. Identify new patterns of H2 production. Hydrogen breath tests data sets as well as k-means clustering as the data mining technique to a dataset of 2571 patients. Six different patterns have been extracted upon analysis of the hydrogen breath test data. We have also shown the relevance of each of the samples taken throughout the test. Analysis of the hydrogen breath test data sets using data mining techniques has identified new patterns of hydrogen generation upon lactose absorption. We can see the potential of application of data mining techniques to clinical data sets. These results offer promising data for future research on the relations between gut microbiota produced hydrogen and its link to clinical symptoms.

  19. NMR determination of photorespiration in intact leaves using in vivo 13CO2 labeling.

    PubMed

    Cegelski, Lynette; Schaefer, Jacob

    2006-01-01

    Solid-state 13C NMR measurements of intact soybean leaves labeled by 13CO2 lead to the conclusion that photorespiration is 17% of photosynthesis for a well-watered and fertilized plant. This is the first direct assessment of the level of photorespiration in a functioning plant. A 13C{31P} rotational-echo double-resonance (REDOR) measurement tracked the incorporation of 13C label into intermediates in the Calvin cycle as a function of time. For labeling times of 5 min or less, the isotopic enrichment of the Calvin cycle depends on the flux of labeled carbon from 13CO2, relative to the flux of unlabeled carbon from glycerate returned from the photorespiratory cycle. Comparisons of these two rates for a fixed value of the 13CO2 concentration indicate that the ratio of the rate of photosynthesis to the rate of photorespiration of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in soybean leaves is 5.7. This translates into a photorespiratory CO2 loss that is 21% of net CO2 assimilation, about 80% of the value estimated from Rubisco kinetics parameters. The ratio of rates is reduced at low external CO2 concentrations, as measured by net carbon assimilation rates. The carbon assimilation was determined from 13C-label spin counts converted into total carbon by the REDOR-determined isotopic enrichments of the Calvin cycle. The net carbon assimilation rates indicate that the rate of decarboxylation of glycine is not directly proportional to the oxygenase activity of Rubisco as is commonly assumed.

  20. NMR determination of photorespiration in intact leaves using in vivo 13CO 2 labeling

    NASA Astrophysics Data System (ADS)

    Cegelski, Lynette; Schaefer, Jacob

    2006-01-01

    Solid-state 13C NMR measurements of intact soybean leaves labeled by 13CO 2 lead to the conclusion that photorespiration is 17% of photosynthesis for a well-watered and fertilized plant. This is the first direct assessment of the level of photorespiration in a functioning plant. A 13C{ 31P} rotational-echo double-resonance (REDOR) measurement tracked the incorporation of 13C label into intermediates in the Calvin cycle as a function of time. For labeling times of 5 min or less, the isotopic enrichment of the Calvin cycle depends on the flux of labeled carbon from 13CO 2, relative to the flux of unlabeled carbon from glycerate returned from the photorespiratory cycle. Comparisons of these two rates for a fixed value of the 13CO 2 concentration indicate that the ratio of the rate of photosynthesis to the rate of photorespiration of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in soybean leaves is 5.7. This translates into a photorespiratory CO 2 loss that is 21% of net CO 2 assimilation, about 80% of the value estimated from Rubisco kinetics parameters. The ratio of rates is reduced at low external CO 2 concentrations, as measured by net carbon assimilation rates. The carbon assimilation was determined from 13C-label spin counts converted into total carbon by the REDOR-determined isotopic enrichments of the Calvin cycle. The net carbon assimilation rates indicate that the rate of decarboxylation of glycine is not directly proportional to the oxygenase activity of Rubisco as is commonly assumed.

  1. Breathing simulator of workers for respirator performance test.

    PubMed

    Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

    2015-01-01

    Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

  2. Interaction of 13 CO 2 and bicarbonate with human hemoglobin preparations.

    PubMed

    Morrow, J S; Keim, P; Visscher, R B; Marshall, R C; Gurd, F R

    1973-05-01

    Formation of (13)C-resonances attributable to carbamino derivatives has been observed in human erythrocyte hemolysate preparations equilibrated with (13)CO(2) at 33 degrees . Carbamino formation is most marked in deoxyhemoglobin and at alkaline pH, and is very largely inhibited by the addition of 2,3-diphosphoglycerate or conversion to oxyhemoglobin. The prominent carbamino resonance at 30.0 ppm upfield of CS(2) is visible in the spectrum of packed, deoxygenated erythrocytes equilibrated in (13)CO(2). This chemical shift falls close to that observed with sperm-whale myoglobin and within 2 ppm upfield of that seen with simple amino acids and peptides. The bicarbonate-carbonate resonance near 33 ppm is broad in the hemoglobin preparations, which always contain some carbonic anhydrase, but becomes narrow in the presence of the carbonic anhydrase inhibitor, acetazolamide. The nuclear magnetic resonance condition of intermediate exchange rate with dissolved CO(2) (68.4 ppm) obtains in the absence of inhibitor. The process has marked consequences in reducing the spin-lattice relaxation time, T(1), of the bicarbonate resonance by more than 10 times. The deoxyhemoglobin carbamino resonance has a T(1) value of 700 msec, indistinguishable from that of the protein carbonyl resonance envelope.

  3. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    NASA Astrophysics Data System (ADS)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  4. The stable isotope ketoisocaproic acid breath test as a measure of hepatic decarboxylation capacity: a quantitative analysis in normal subjects after oral and intravenous administration.

    PubMed

    Berthold, Heiner K; Giesen, Thomas A H; Gouni-Berthold, Ioanna

    2009-10-01

    There is no generally accepted kinetic evaluation method for the stable isotope [(13)C]ketoisocaproic acid (KIC) breath test. Differences found in the results between women and men are contradictory. Oral and intravenous breath tests using 1 mg/kg stable isotope-labelled KIC were performed in healthy male and female volunteers. A power exponential function was fitted to the mass spectrometric data of breath (13)CO(2) enrichment, allowing mathematical analysis of time-to-peak-excretion, half-excretion time, percent label recovery and parameters describing the shape of the curve. Body composition was determined using bioelectrical impedance analysis. After oral administration, total label recovery after 3 h was about 22% and was not different between men (n=7) and women (n=8). The time to maximal label excretion was 0.67 +/- 0.12 h in men and 0.9 +/- 0.32 h in women (P=0.028) and the excretion curve showed an initially slower rise in women compared with men. Adjusting for lean body mass or body water abrogated the sex differences. Total label recovery after intravenous administration was about 9%, suggesting that the substrate was rapidly catabolized in the muscle compartment after intravenous administration. The modified power exponential function described allows standardized estimates of the KIC breath test results. When corrected for body composition, there are no differences in breath test results between men and women. The comparison between oral and intravenous results provides robust evidence that the KIC breath test measures predominantly hepatic and not muscle decarboxylation and is thus a highly specific liver function test.

  5. Sensors for breath testing: from nanomaterials to comprehensive disease detection.

    PubMed

    Konvalina, Gady; Haick, Hossam

    2014-01-21

    The analysis of volatile organic compounds in exhaled breath samples represents a new frontier in medical diagnostics because it is a noninvasive and potentially inexpensive way to detect illnesses. Clinical trials with spectrometry and spectroscopy techniques, the standard volatile-compound detection methods, have shown the potential for diagnosing illnesses including cancer, multiple sclerosis, Parkinson's disease, tuberculosis, diabetes, and more via breath tests. Unfortunately, this approach requires expensive equipment and high levels of expertise to operate the necessary instruments, and the tests must be done quickly and use preconcentration techniques, all of which impede its adoption. Sensing matrices based on nanomaterials are likely to become a clinical and laboratory diagnostic tool because they are significantly smaller, easier-to-use, and less expensive than spectrometry or spectroscopy. An ideal nanomaterial-based sensor for breath testing should be sensitive at very low concentrations of volatile organic compounds, even in the presence of environmental or physiological confounding factors. It should also respond rapidly and proportionately to small changes in concentration and provide a consistent output that is specific to a given volatile organic compound. When not in contact with the volatile organic compounds, the sensor should quickly return to its baseline state or be simple and inexpensive enough to be disposable. Several reviews have focused on the methodological, biochemical, and clinical aspects of breath analysis in attempts to bring breath testing closer to practice for comprehensive disease detection. This Account pays particular attention to the technological gaps and confounding factors that impede nanomaterial-sensor-based breath testing, in the hope of directing future research and development efforts towards the best possible approaches to overcome these obstacles. We discuss breath testing as a complex process involving numerous

  6. Ecological and Molecular Study of Soil Chemoautotrophic Microorganisms via the Sequestration of Atmospheric 13CO2

    NASA Astrophysics Data System (ADS)

    Hart, K. M.; Kelleher, B.; Allen, C.; Simpson, A.

    2009-05-01

    Soil Organic Matter (SOM) is the most complicated biomaterial on Earth and stores significantly more carbon than is currently present in the atmosphere [1]. It has been recently reported that humic material in SOM is a highly complex mixture of microbial and plant biopolymers and not a distinct chemical fraction as previously thought [2]. Furthermore, it has been reported that the microbial biomass contribution to SOM is not comprised of mainly humic materials and that in fact the contribution to SOM by soil microorganisms has been seriously underestimated [3]. Therefore, the question arises if we underestimate microbial biomass in soil do we also underestimate carbon sequestration by soil microbes? Soil microorganisms consist of a large range of diverse species with soil bacteria contributing a large proportion of the biomass content. Autotrophs are organisms that can produce organic compounds from CO2 as the sole carbon source, using either light (photoautotroph) or inorganic reactions (chemoautotroph) as the energy source. The aim of this project is to enrich chemoautotrophic soil microbes with carbon-13 (13C) sequestered as 13CO2. Once labeled, these target microbes can be differentiated from other microbes using techniques such as Stable Isotope Probing (SIP) and carbon NMR. This enrichment is facilitated via incubation in a custom built environmental chamber and the controlled introduction of 13CO2. Before introduction of 13CO2 the chambers capabilities had to be fully characterized to ensure that it was fit for purpose. Mixed cultures of soil chemoautotrophic microorganisms were propagated from different soils and data collected using the environmental chamber demonstrated that CO2 fluctuations mimicked the natural activity of actively growing chemoautotrophic cultures. Therefore using this soil slurry approach, a mixed culture of soil autotrophs will be exposed to 13CO2 prior to the harvesting of the microbial biomass. Ion chromatographic analysis of the

  7. 13C-Breath Tests for Sucrose Digestion in Congenital Sucrase Isomaltase Deficient and Sacrosidase Supplemented Patients

    PubMed Central

    Robayo-Torres, Claudia C.; Opekun, Antone R.; Quezada-Calvillo, Roberto; Xavier, Villa; Smith, E. O’Brian; Navarrete, Marilyn; Baker, S. Susan; Nichols, Buford L

    2008-01-01

    Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is useful but is not specific for confirmation of CSID. We investigated a more specific 13C-sucrose labeled BT. Objectives were to determine if CSID can be detected with the 13C-sucrose BT without duodenal biopsy sucrase assay and if the 13C-sucrose BT can document restoration of sucrose digestion by CSID patients after oral supplementation with sacrosidase (Sucraid®). Methods Ten CSID patients were diagnosed by low biopsy sucrase activity. Ten controls were children who underwent endoscopy and biopsy because of dyspepsia or chronic diarrhea with normal mucosal enzymes activity and histology. Uniformly-labeled 13C-glucose and 13C-sucrose loads were orally administered. 13CO2 breath enrichments were assayed using an infrared spectrophotometer. In CSID patients the 13C-sucrose load was repeated adding Sucraid®. Sucrose digestion and oxidation were calculated as a mean % coefficient of glucose oxidation (% CGO) averaged between 30 and 90 minutes. Results Classification of patients by 13C-sucrose BT % CGO agreed with biopsy sucrase activity. The breath test also documented the return to normal of sucrose digestion and oxidation after supplementation of CSID patients with Sucraid®. Conclusion 13C-sucrose BT is an accurate and specific non-invasive confirmatory test for CSID and for enzyme replacement management. PMID:19330928

  8. Data Mining Techniques Applied to Hydrogen Lactose Breath Test

    PubMed Central

    Nepomuceno-Chamorro, Isabel; Pontes-Balanza, Beatriz; Hernández-Mendoza, Yoedusvany; Rodríguez-Herrera, Alfonso

    2017-01-01

    In this work, we present the results of applying data mining techniques to hydrogen breath test data. Disposal of H2 gas is of utmost relevance to maintain efficient microbial fermentation processes. Objectives Analyze a set of data of hydrogen breath tests by use of data mining tools. Identify new patterns of H2 production. Methods Hydrogen breath tests data sets as well as k-means clustering as the data mining technique to a dataset of 2571 patients. Results Six different patterns have been extracted upon analysis of the hydrogen breath test data. We have also shown the relevance of each of the samples taken throughout the test. Conclusions Analysis of the hydrogen breath test data sets using data mining techniques has identified new patterns of hydrogen generation upon lactose absorption. We can see the potential of application of data mining techniques to clinical data sets. These results offer promising data for future research on the relations between gut microbiota produced hydrogen and its link to clinical symptoms. PMID:28125620

  9. New optical analyzer for 13C-breath test

    NASA Astrophysics Data System (ADS)

    Harde, Hermann; Dressler, Matthias; Helmrich, Günther; Wolff, Marcus; Groninga, Hinrich

    2008-04-01

    Medical breath tests are well established diagnostic tools, predominantly for gastroenterological inspections, but also for many other examinations. Since the composition and concentration of exhaled volatile gases reflect the physical condition of a patient, a breath analysis allows one to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that is based on photoacoustic spectroscopy and uses a DFB diode laser at 2.744 μm. The concentration ratio of the CO II isotopologues is determined by measuring the absorption on a 13CO II line in comparison to a 12CO II line. In the specially selected spectral range the lines have similar strengths, although the concentrations differ by a factor of 90. Therefore, the signals are well comparable. Due to an excellent signal-noise-ratio isotope variations of less than 1% can be resolved as required for the breath test.

  10. [Irregular breathing during the cardiopulmonary exercise test - from mildly irregular breathing pattern to periodic breathing of oscillatory ventilation type].

    PubMed

    Várnay, František; Mífková, Leona; Homolka, Pavel; Dobšák, Petr

    2017-01-01

    The fluctuating course of tidal volume (VT), breathing frequency (DF) and minute ventilation (VE) during the cardio-pulmonary exercise test using a ramp incremental protocol occurs not only in patients, but relatively frequently also in healthy individuals. It can account for a number of irregularities in the course of the curves VO2, VCO2 and in particular of those of ventilatory equivalents for O2 and CO2 (EQO2, EQCO2) as well as curves of partial pressure of end-tidal oxygen and partial pressure of end-tidal carbon dioxide (PETO2, PETCO2), which are also used, inter alia, to establish ventilatory thresholds. The presence of exercise oscillatory ventilation (EOV) reflects the severity of heart failure and it is an independent predictor of the increased morbidity, cardiac and total mortality and sudden death caused by heart failure. However there is not a generally accepted universal definition of EOV available at present, as different criteria are used. We have not found a comparison which would indicate whether and how the "strength" of the prognostic criteria for EOV - established according to different methods - differs. Therefore it is very important to specify what method, or what criteria were used in the establishment of EOV.Key words: breathing pattern - EOV - exercise oscillatory ventilation - periodic breathing.

  11. Tracing photosynthetic carbon in leaves with nanoSIMS after 13CO2 labelling

    NASA Astrophysics Data System (ADS)

    Dannoura, Masako; Takeuchi, Miyuki; Kominami, Yuji; Takanashi, Satoru; Kenichi, Yoshimura; Ataka, Mioko

    2015-04-01

    To understand the carbon allocation of the tree and forest ecosystem, it is important to consider the residence time of carbon in different pools at suitable time scales. For example the carbon used for respiration will stay a few minutes to a few days in the tree, the carbon used for storage or structure of leaves will stay months to years, and the carbon used for wood structure, it will stay over the whole lifespan of the tree. The leaves are the entrance of carbon in trees where it can be used for foliage growth and maintenance or exported to the other organs or the other forest ecosystem compartments. Tracing carbon isotope using NanoSIMS technique is one of useful methods to estimate where and how long the carbon stay in the tree organs. In this study, 13CO2 pulse labelling were conducted and 13C was measured by IRMS to see the amount of C remaining in the leaves with time.NanoSIMS was used to localize where the labelled C remained within the leaf tissue. Twice labelling were done on branches of Quercus serrata at FFPRI(Forest and Forest Products research Institute) in Kyoto, Japan. The first labelling was in 30 April 2012 when the leaves start flushing and the second one was in 29 May 2012 when the leaves were completely deployed. For both labelling experiment, one branch was selected and covered with transparent plastic bag. CO2 concentration was recorded with IRGA and air temperature inside the chamber was monitored. Then 13CO2 was injected into the bag, and after 1 hour, the bag was removed and the branch was again exposed to ambient air. Leaves were collected before and 10-12 times after labelling and their isotope compositions were measured by IRMS. The leaf collected just after labelling and 6 days after labelling were used for NanoSIMS observation. Samples for nanoSIMS were preserved in glutaraldehyde and then embed in epoxy resin. The sliced sample were placed on the silicon wafer and observed by NanoSIMS 50L(Cameca, France). The 13C was highest just

  12. Impaired gastric emptying of a solid test meal in patients with Parkinson's disease using 13C-sodium octanoate breath test.

    PubMed

    Goetze, Oliver; Wieczorek, Joerg; Mueller, Thomas; Przuntek, Horst; Schmidt, Wolfgang E; Woitalla, Dirk

    2005-03-03

    Up to now gastric emptying in patients with Parkinson's disease was determined by radioscintigraphy. The 13C-sodium octanoate breath test (OBT) has been established for the non-invasive evaluation of gastric emptying with a solid test meal. The aim of the study was to evaluate the OBT in patients with Parkinson's disease and to investigate the prevalence of delayed gastric emptying for solids in PD and the relationship to clinical staging patterns. Twenty-two healthy subjects and 36 patients with different clinical stages of PD classified using Hoehn and Yahr (H&Y) and Unified Parkinson's Disease Rating Scale (UPDRS) were studied. Each fasting control and patient received a solid test meal (241 kcal) labelled with 100 mg of 13C-sodium octanoate. Breath samples were obtained before substrate administration and then in 15-min intervals over 4 h. The 13CO2/12CO2 ratio was determined in each breath sample as delta over baseline. Time to peak (t(peak)), gastric half emptying time (t1/2b), lag phase (t(lagb)) and gastric emptying coefficient (GEC) were calculated. Significant differences in t(peak), t1/2b, t(lagb) and GEC were found between patients and healthy volunteers (p<0.0001), with a 60% delay in gastric half emptying time in the patient group. Gastric half emptying time was different between clinical disease groups (H&Y 0-2 versus H&Y 2.5-5, p=0.001; UPDRS 0-30 versus UPDRS 61-92, p<0.05). The OBT detects a significant delay in gastric emptying of a solid test meal in patients with PD. Delayed gastric emptying for solids is associated with disease severity.

  13. Decreased metabolism of 13C-caffeine via hepatic CYP1A2 in marasmus and kwashiorkor based on breath test.

    PubMed

    Oshikoya, Kazeem Adeola; Smith, Kenneth; Sammons, Helen; Choonara, Imti

    2015-01-01

    Hepatic metabolism of drugs has been rarely studied in children with malnutrition. Caffeine breath test (CBT) has been used to determine the activity of cytochrome P450 1A2 (CYP1A2) enzymes in children. We used the CBT to assess how marasmus and kwashiorkor differentially affect 13C-caffeine metabolism. A total of 45 children composed of 15 children per group of malnutrition (marasmus, marasmic-kwashiorkor, and kwashiorkor) were studied during malnutrition and after nutritional recovery. After an overnight fast, patients ingested 3 mg/kg 13C-caffeine at 0900 h. Duplicate breath samples were collected into an Exetainer bottle at -20, -10, and -1 min and at 15-min intervals for 2 h. The mean cumulative percent dose recovered (CPDR) of 13C-caffeine in the expired 13CO2 was determined over the study period. The CPDR in the expired 13CO2 in 2 h significantly increased after nutritional recovery in children with marasmus (from 6.80%±3.00% to 7.67%±2.81%; Student's t-test, p=0.001), marasmic-kwashiorkor (from 6.61%±2.26% to 7.56%±2.46%, p=0.041), and kwashiorkor (from 6.29%±1.06% to 7.20%±1.80%, p=0.002). When the three groups of malnutrition were compared, there was no significant difference in their mean CPDR in 2 h during malnutrition [p=0.820, analysis of variance (ANOVA)] and after nutritional recovery (p=0.810, ANOVA). Hepatic metabolism of caffeine significantly decreased in children with marasmus, marasmic-kwashiorkor, and kwashiorkor compared to after they had recovered nutritionally. This suggests a decreased CYP1A2 activity in all categories of malnutrition.

  14. Evaluating the Community Land Model in a pine stand with shading manipulations and 13CO2 labeling

    DOE PAGES

    Mao, Jiafu; Ricciuto, Daniel M.; Thornton, Peter E.; ...

    2016-02-03

    Carbon partitioning and flow through ecosystems regulates land surface atmosphere CO2 exchange and thus is a key, albeit uncertain component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked C partitioning through a young Pinus taeda stand following pulse-labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that was used to evaluate and improve terrestrial biosphere model simulations of rapid shifts in carbon partitioning and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbonmore » and water dynamics in relation to manipulative shading treatments, and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. To constrain CLM4 to closely simulate pretreatment conditions, we calibrated select model parameters with the pretreatment observational data. Compared to CLM4 simulations with default parameters, CLM4 with calibrated model parameters was better able to simulate pretreatment vegetation carbon pools, light response curves, and other initial states and fluxes of carbon and water. Over a 3-week treatment period, the calibrated CLM4 generally reproduced the impacts of shading on average soil moisture at 15-95 cm depth, transpiration, relative change in stem carbon, and soil CO2 efflux rate, although some discrepancies in the estimation of magnitudes and temporal evolutions existed. CLM4, however, was not able to track the progression of the 13CO2 label from the atmosphere through foliage, phloem, roots or surface soil CO2 efflux, even when optimized model parameters were used. This model bias arises, in part, from the lack of a short-term non-structural carbohydrate storage pool and progressive timing of within-plant transport, thus indicating a need for future work to improve the allocation routines in CLM4

  15. Evaluating the Community Land Model in a pine stand with 13CO2 labeling and shading manipulations

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ricciuto, D. M.; Thornton, P. E.; Warren, J. M.; King, A. W.; Shi, X.; Iversen, C. M.; Norby, R. J.

    2015-05-01

    Carbon allocation and flow through ecosystems regulate land surface-atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked carbon allocation through a young Pinus taeda stand following pulse-labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that was used to evaluate and improve terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments, and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. For CLM4 to closely simulate pretreatment conditions, we calibrated select model parameters with pretreatment observational data. Compared to CLM4 simulations with default parameters, CLM4 with calibrated model parameters was able to better simulate pretreatment vegetation carbon pools, light response curves, and other initial states and fluxes of carbon and water. Over a 3 week treatment period, the calibrated CLM4 generally reproduced the impacts of shading on average soil moisture at 15-95 cm depth, transpiration, relative change in stem carbon, and soil CO2 efflux rate, although some discrepancies in the estimation of magnitudes and temporal evolutions existed. CLM4, however, was not able to track the progression of the 13CO2 label from the atmosphere through foliage, phloem, roots or surface soil CO2 efflux, even when optimized model parameters were used. This model bias arises, in part, from the lack of a short-term non-structural carbohydrate storage pool and progressive timing of within-plant transport, thus indicating a need for future work to improve the allocation routines in CLM4. Overall, these types

  16. 13C Tracking after 13CO2 Supply Revealed Diurnal Patterns of Wood Formation in Aspen.

    PubMed

    Mahboubi, Amir; Linden, Pernilla; Hedenström, Mattias; Moritz, Thomas; Niittylä, Totte

    2015-06-01

    Wood of trees is formed from carbon assimilated in the photosynthetic tissues. Determining the temporal dynamics of carbon assimilation, subsequent transport into developing wood, and incorporation to cell walls would further our understanding of wood formation in particular and tree growth in general. To investigate these questions, we designed a (13)CO2 labeling system to study carbon transport and incorporation to developing wood of hybrid aspen (Populus tremula × tremuloides). Tracking of (13)C incorporation to wood over a time course using nuclear magnetic resonance spectroscopy revealed diurnal patterns in wood cell wall biosynthesis. The dark period had a differential effect on (13)C incorporation to lignin and cell wall carbohydrates. No (13)C was incorporated into aromatic amino acids of cell wall proteins in the dark, suggesting that cell wall protein biosynthesis ceased during the night. The results show previously unrecognized temporal patterns in wood cell wall biosynthesis, suggest diurnal cycle as a possible cue in the regulation of carbon incorporation to wood, and establish a unique (13)C labeling method for the analysis of wood formation and secondary growth in trees.

  17. Noninvasive assessment of insulin resistance in the liver using the fasting (13)C-glucose breath test.

    PubMed

    Tanaka, Ken; Matsuura, Tomokazu; Shindo, Daisuke; Aida, Yuta; Matsumoto, Yoshihiro; Nagatsuma, Keisuke; Saito, Masaya; Ishii, Hirotaka; Abe, Hiroshi; Tanaka, Fumihiko; Shimada, Takao; Nakada, Koji; Ikewaki, Katsunori; Aizawa, Yoshio; Tajiri, Hisao; Suzuki, Masato

    2013-09-01

    Evaluating hepatic insulin resistance (IR) is the key to making a sensitive an accurate diagnosis of glucose intolerance. However, there is currently no suitable method to perform this procedure. This study was conducted to investigate whether the fasting (13)C-glucose breath test (FGBT) is useful as a convenient and highly sensitive clinical test for evaluating hepatic IR. Healthy nonobese subjects and a disease group consisting of patients with mild glucose intolerance were administered 100 mg (13)C-glucose after an overnight fast. A series of breath samples was collected until 360 minutes after ingestion, and the (13)CO2-to-(12)CO2 ratio was measured using an infrared spectrometer and was plotted as a kinetic curve of (13)C excretion. The area under the curve until 360 minutes (AUC360) of the (13)C excretion kinetic curve of the FGBT reflects the efficiency of energy production in the liver. First, we assessed the correlations between the AUC360 (or the (13)C excretion rate at 120 minutes) and the HOMA-IR and HbA1c levels as standard measurements of IR and diabetes mellitus (DM). There were relatively strong correlation coefficients (r = -0.49 to -0.81, r(2) = 0.24-0.66, P < 0.01; n = 35 males, n = 33 females). Second, we compared the AUC360 of healthy subjects and that of the patients with mild glucose intolerance. The AUC360 of the healthy subjects was consistently higher than that of the patients with mild glucose intolerance. The presence of IR or DM in males and females was diagnosed using cutoff values. The FGBT is a novel glucose metabolism test that can be used conveniently and safely to evaluate the balance of glucose metabolism in the liver. This test has excellent sensitivity for diagnosing alterations in hepatic glucose metabolism, particularly hepatic IR. Copyright © 2013 Mosby, Inc. All rights reserved.

  18. Evaluation of periesophageal nerve injury after pulmonary vein isolation using the (13)C-acetate breath test.

    PubMed

    Kanaeda, Tomonori; Ueda, Marehiko; Arai, Makoto; Ishimura, Masayuki; Kajiyama, Takatsugu; Hashiguchi, Naotaka; Nakano, Masahiro; Kondo, Yusuke; Hiranuma, Yasunori; Oyamada, Arata; Yokosuka, Osamu; Kobayashi, Yoshio

    2015-12-01

    Pulmonary vein isolation (PVI) has become an important option for treating patients with atrial fibrillation (AF). Periesophageal nerve (PEN) injury after PVI causes pyloric spasms and gastric hypomotility. This study aimed to clarify the impact of PVI on gastric motility and assess the prevalence of gastric hypomotility after PVI. Thirty consecutive patients with AF underwent PVI under luminal esophageal temperature (LET) monitoring. The (13)C-acetate breath test was conducted before and after the procedure for all patients (PVI group). Gastric emptying was evaluated using the time to peak concentration of (13)CO2 (T max). This test was also conducted in another 20 patients who underwent catheter ablation procedures other than PVI (control group). The number of patients with abnormal T max (≥75 min) increased from seven (23%) to 13 (43%) and from three (15%) to five (25%) after the procedure in the PVI group and control group, respectively. The mean T max was longer after PVI than before PVI (64±14 min vs. 57±15 min, p=0.006), whereas there was no significant difference before and after the procedure in the control group. However, no significant difference in ΔT max was observed between the two groups (p=0.27). No patients suffered from symptomatic gastric hypomotility. Asymptomatic gastric hypomotility occurred more often after PVI. However, the average impact of PVI on gastric motility was minimal.

  19. A joint global carbon inversion system using both CO2 and 13CO2 atmospheric concentration data

    NASA Astrophysics Data System (ADS)

    Chen, Jing M.; Mo, Gang; Deng, Feng

    2017-03-01

    Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites (62 collocated with 13CO2 sites) for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using prior CO2 fluxes estimated with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. This joint inversion system using both13CO2 and CO2 observations is effectively a double deconvolution system with consideration of the spatial variations of isotopic discrimination and disequilibrium. Compared to the CO2-only inversion, this 13CO2 constraint on the inversion considerably reduces the total land carbon sink from 3.40 ± 0.84 to 2.53 ± 0.93 Pg C year-1 but increases the total oceanic carbon sink from 1.48 ± 0.40 to 2.36 ± 0.49 Pg C year-1. This constraint also changes the spatial distribution of the carbon sink. The largest sink increase occurs in the Amazon, while the largest source increases are in southern Africa, and Asia, where CO2 data are sparse. Through a case study, in which the spatial distribution of the annual 13CO2 discrimination rate over land is ignored by treating it as a constant at the global average of -14. 1 ‰, the spatial distribution of the inverted CO2 flux over land was found to be significantly modified (up to 15 % for some regions). The uncertainties in our disequilibrium flux estimation are 8.0 and 12.7 Pg C year-1 ‰ for land and ocean, respectively. These uncertainties induced the unpredictability of 0.47 and 0.54 Pg C year-1 in the inverted CO2 fluxes for land and ocean, respectively. Our joint inversion system is therefore

  20. The importance of methane breath testing: a review.

    PubMed

    de Lacy Costello, B P J; Ledochowski, M; Ratcliffe, N M

    2013-06-01

    Sugar malabsorption in the bowel can lead to bloating, cramps, diarrhea and other symptoms of irritable bowel syndrome as well as affecting absorption of other nutrients. The hydrogen breath test is now a well established noninvasive test for assessing malabsorption of sugars in the small intestine. However, there are patients who can suffer from the same spectrum of malabsorption issues but who produce little or no hydrogen, instead producing relatively large amounts of methane. These patients will avoid detection with the traditional breath test for malabsorption based on hydrogen detection. Likewise the hydrogen breath test is an established method for small intestinal bacterial overgrowth (SIBO) diagnoses. Therefore, a number of false negatives would be expected for patients who solely produce methane. Usually patients produce either hydrogen or methane, and only rarely there are significant co-producers, as typically the methane is produced at the expense of hydrogen by microbial conversion of carbon dioxide. Various studies show that methanogens occur in about a third of all adult humans; therefore, there is significant potential for malabsorbers to remain undiagnosed if a simple hydrogen breath test is used. As an example, the hydrogen-based lactose malabsorption test is considered to result in about 5-15% false negatives mainly due to methane production. Until recently methane measurements were more in the domain of research laboratories, unlike hydrogen analyses which can now be undertaken at a relatively low cost mainly due to the invention of reliable electrochemical hydrogen sensors. More recently, simpler lower cost instrumentation has become commercially available which can directly measure both hydrogen and methane simultaneously on human breath. This makes more widespread clinical testing a realistic possibility. The production of small amounts of hydrogen and/or methane does not normally produce symptoms, whereas the production of higher levels can

  1. Dumping syndrome following nissen fundoplication in an adult patient diagnosed by continuous online 13C/12C monitoring of 13C-Octanoic acid breath test "a case report"

    PubMed Central

    2011-01-01

    Background Nissen Fundoplication is a common surgical procedure performed in treating gastroesophageal reflux disease (GERD). Complications include dysphagia, gastric hypersensitivity, abnormal gastric motility, gas bloat syndrome and GERD relapse. Dumping syndrome may occur when a large volume of gastric content is delivered to the duodenum or jejunum, resulting in both gastrointestinal and vasomotor symptoms. Occasionally, dumping syndrome may be a complication in patients that have undergone nissen Fundoplication, especially in adults. The BreathID® continuous online 13C-Octanoicoctanoic acid breath test detects variations of less than 1/100,000 in the 13CO2/12CO2 ratio in exhaled air. Case presentation We report a case of a 38 year old male who was admitted and diagnosed with dumping syndrome following nissen Fundoplication, who was diagnosed using the BreathID® continuous online 13C-Octanoic acid breath test. Conclusions Early performance of a gastric emptying rate breath test in symptomatic patients, following upper GI tract surgery may help in the prediction or diagnosis of nissen Fundoplication complications such as dumping syndrome. PMID:21929798

  2. Dumping syndrome following nissen fundoplication in an adult patient diagnosed by continuous online 13C/12C monitoring of ¹³C-Octanoic acid breath test "a case report".

    PubMed

    Mizrahi, Meir; Almogy, Gideon; Adar, Tomer; Lysy, Joseph

    2011-09-19

    Nissen Fundoplication is a common surgical procedure performed in treating gastroesophageal reflux disease (GERD). Complications include dysphagia, gastric hypersensitivity, abnormal gastric motility, gas bloat syndrome and GERD relapse. Dumping syndrome may occur when a large volume of gastric content is delivered to the duodenum or jejunum, resulting in both gastrointestinal and vasomotor symptoms. Occasionally, dumping syndrome may be a complication in patients that have undergone nissen Fundoplication, especially in adults. The BreathID® continuous online 13C-Octanoicoctanoic acid breath test detects variations of less than 1/100,000 in the 13CO2/12CO2 ratio in exhaled air. We report a case of a 38 year old male who was admitted and diagnosed with dumping syndrome following nissen Fundoplication, who was diagnosed using the BreathID® continuous online 13C-Octanoic acid breath test. Early performance of a gastric emptying rate breath test in symptomatic patients, following upper GI tract surgery may help in the prediction or diagnosis of nissen Fundoplication complications such as dumping syndrome.

  3. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he or...

  4. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he or...

  5. Decoding Biosynthetic Pathways in Plants by Pulse-Chase Strategies Using 13CO2 as a Universal Tracer †

    PubMed Central

    Bacher, Adelbert; Chen, Fan; Eisenreich, Wolfgang

    2016-01-01

    13CO2 pulse-chase experiments monitored by high-resolution NMR spectroscopy and mass spectrometry can provide 13C-isotopologue compositions in biosynthetic products. Experiments with a variety of plant species have documented that the isotopologue profiles generated with 13CO2 pulse-chase labeling are directly comparable to those that can be generated by the application of [U-13C6]glucose to aseptically growing plants. However, the application of the 13CO2 labeling technology is not subject to the experimental limitations that one has to take into account for experiments with [U-13C6]glucose and can be applied to plants growing under physiological conditions, even in the field. In practical terms, the results of biosynthetic studies with 13CO2 consist of the detection of pairs, triples and occasionally quadruples of 13C atoms that have been jointly contributed to the target metabolite, at an abundance that is well above the stochastic occurrence of such multiples. Notably, the connectivities of jointly transferred 13C multiples can have undergone modification by skeletal rearrangements that can be diagnosed from the isotopologue data. As shown by the examples presented in this review article, the approach turns out to be powerful in decoding the carbon topology of even complex biosynthetic pathways. PMID:27429012

  6. Low dose capsule based 13c-urea breath test compared with the conventional 13c-urea breath test and invasive tests.

    PubMed

    Mattar, Rejane; Villares, Cibele Aparecida; Marostegam, Priscila Faria França; Chaves, Cleuber Esteves; Pinto, Vanusa Barbosa; Carrilho, Flair José

    2014-01-01

    One of the limitations of 13C-urea breath test for Helicobacter pylori infection diagnosis in Brazil is the substrate acquisition in capsule presentation. The purpose of this study was to evaluate a capsule-based 13C-urea, manipulated by the Pharmacy Division, for the clinical practice. Fifty patients underwent the conventional and the capsule breath test. Samples were collected at the baseline and after 10, 20 and 30 minutes of 13C-urea ingestion. Urease and histology were used as gold standard in 83 patients. In a total of 50 patients, 17 were positive with the conventional 13C-urea (75 mg) breath test at 10, 20 and 30 minutes. When these patients repeated breath test with capsule (50 mg), 17 were positive at 20 minutes and 15 at 10 and 30 minutes. The relative sensitivity of 13C-urea with capsule was 100% at 20 minutes and 88.24% at 10 and at 30 minutes. The relative specificity was 100% at all time intervals. Among 83 patients that underwent capsule breath test and endoscopy the capsule breath test presented 100% of sensitivity and specificity. Capsule based breath test with 50 mg 13C-urea at twenty minutes was found highly sensitive and specific for the clinical setting.

  7. Constraining Ecosystem Gross Primary Production and Transpiration with Measurements of Photosynthetic 13CO2 Discrimination

    NASA Astrophysics Data System (ADS)

    Blonquist, J. M.; Wingate, L.; Ogeé, J.; Bowling, D. R.

    2011-12-01

    The stable carbon isotope composition of atmospheric CO2 (δ13Ca) can provide useful information on water use efficiency (WUE) dynamics of terrestrial ecosystems and potentially constrain models of CO2 and water fluxes at the land surface. This is due to the leaf-level relationship between photosynthetic 13CO2 discrimination (Δ), which influences δ13Ca, and the ratio of leaf intercellular to atmospheric CO2 mole fractions (Ci / Ca), which is related to WUE and is determined by the balance between C assimilation (CO2 demand) and stomatal conductance (CO2 supply). We used branch-scale Δ derived from tunable diode laser absorption spectroscopy measurements collected in a Maritime pine forest to estimate Ci / Ca variations over an entire growing season. We combined Ci / Ca estimates with rates of gross primary production (GPP) derived from eddy covariance (EC) to estimate canopy-scale stomatal conductance (Gs) and transpiration (T). Estimates of T were highly correlated to T estimates derived from sapflow data (y = 1.22x + 0.08; r2 = 0.61; slope P < 0.001) and T predictions from an ecosystem model (MuSICA) (y = 0.88x - 0.05; r2 = 0.64; slope P < 0.001). As an alternative to estimating T, Δ measurements can be used to estimate GPP by combining Ci / Ca estimates with Gs estimates from sapflow data. Estimates of GPP were determined in this fashion and were highly correlated to GPP values derived from EC (y = 0.82 + 0.07; r2 = 0.61; slope P < 0.001) and GPP predictions from MuSICA (y = 1.10 + 0.42; r2 = 0.50; slope P < 0.001). Results demonstrate that the leaf-level relationship between Δ and Ci / Ca can be extended to the canopy-scale and that Δ measurements have utility for partitioning ecosystem-scale CO2 and water fluxes.

  8. The glucose breath test: a diagnostic test for small bowel stricture(s) in Crohn's disease.

    PubMed

    Mishkin, Daniel; Boston, Francis M; Blank, David; Yalovsky, Morty; Mishkin, Seymour

    2002-03-01

    The aim of this study was to determine whether an indirect noninvasive indicator of proximal bacterial overgrowth, the glucose breath test, was of diagnostic value in inflammatory bowel disease. Twenty four of 71 Crohn's disease patients tested had a positive glucose breath test. No statistical conclusions could be drawn between the Crohn's disease activity index and glucose breath test status. Of patients with radiologic evidence of small bowel stricture(s), 96.0% had a positive glucose breath test, while only one of 46 negative glucose breath test patients had a stricture. The positive and negative predictive values for a positive glucose breath test as an indicator of stricture formation were 96.0% and 97.8%, respectively. This correlation was not altered in Crohn's disease patients with fistulae or status postresection of the terminal ileum. The data in ulcerative colitis were nondiagnostic. In conclusion, the glucose breath test appears to be an accurate noninvasive inexpensive diagnostic test for small bowel stricture(s) and secondary bacterial overgrowth in Crohn's disease.

  9. Partitioning net ecosystem carbon exchange into net assimilation and respiration using 13CO2 measurements: A cost-effective sampling strategy

    NASA Astrophysics Data System (ADS)

    OgéE, J.; Peylin, P.; Ciais, P.; Bariac, T.; Brunet, Y.; Berbigier, P.; Roche, C.; Richard, P.; Bardoux, G.; Bonnefond, J.-M.

    2003-06-01

    The current emphasis on global climate studies has led the scientific community to set up a number of sites for measuring the long-term biosphere-atmosphere net CO2 exchange (net ecosystem exchange, NEE). Partitioning this flux into its elementary components, net assimilation (FA), and respiration (FR), remains necessary in order to get a better understanding of biosphere functioning and design better surface exchange models. Noting that FR and FA have different isotopic signatures, we evaluate the potential of isotopic 13CO2 measurements in the air (combined with CO2 flux and concentration measurements) to partition NEE into FR and FA on a routine basis. The study is conducted at a temperate coniferous forest where intensive isotopic measurements in air, soil, and biomass were performed in summer 1997. The multilayer soil-vegetation-atmosphere transfer model MuSICA is adapted to compute 13CO2 flux and concentration profiles. Using MuSICA as a "perfect" simulator and taking advantage of the very dense spatiotemporal resolution of the isotopic data set (341 flasks over a 24-hour period) enable us to test each hypothesis and estimate the performance of the method. The partitioning works better in midafternoon when isotopic disequilibrium is strong. With only 15 flasks, i.e., two 13CO2 nighttime profiles (to estimate the isotopic signature of FR) and five daytime measurements (to perform the partitioning) we get mean daily estimates of FR and FA that agree with the model within 15-20%. However, knowledge of the mesophyll conductance seems crucial and may be a limitation to the method.

  10. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

  11. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... chemical test of bodily fluids or breath will result in the revocation of driving privileges. (c) As stated... given breath or urine tests, or both. (e) If a person suspected of intoxicated driving refuses to submit... 32 National Defense 4 2011-07-01 2011-07-01 false Voluntary breath and bodily fluid testing based...

  12. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false FRA access to breath test results. 219.206 Section 219.206 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

  13. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chemical test of bodily fluids or breath will result in the revocation of driving privileges. (c) As stated... given breath or urine tests, or both. (e) If a person suspected of intoxicated driving refuses to submit... 32 National Defense 4 2010-07-01 2010-07-01 true Voluntary breath and bodily fluid testing based...

  14. Evaluating the Community Land Model in a pine stand with shading manipulations and 13CO2 labeling

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ricciuto, D. M.; Thornton, P. E.; Warren, J. M.; King, A. W.; Shi, X.; Iversen, C. M.; Norby, R. J.

    2016-02-01

    Carbon allocation and flow through ecosystems regulates land surface-atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked carbon allocation through a young Pinus taeda stand following pulse labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that were used to evaluate terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. When calibrated with pretreatment observations, CLM4 was capable of closely simulating stand-level biomass, transpiration, leaf-level photosynthesis, and pre-labeling 13C values. Over the 3-week treatment period, CLM4 generally reproduced the impacts of shading on soil moisture changes, relative change in stem carbon, and soil CO2 efflux rate. Transpiration under moderate shading was also simulated well by the model, but even with optimization we were not able to simulate the high levels of transpiration observed in the heavy shading treatment, suggesting that the Ball-Berry conductance model is inadequate for these conditions. The calibrated version of CLM4 gave reasonable estimates of label concentration in phloem and in soil surface CO2 after 3 weeks of shade treatment, but it lacks the mechanisms needed to track the labeling pulse through plant tissues on shorter timescales. We developed a conceptual model for photosynthate transport based on the experimental observations, and we discussed conditions under which the hypothesized mechanisms could have an important influence on model behavior in larger-scale applications

  15. Effects of Ergot Alkaloids on Liver Function of Piglets as Evaluated by the 13C-Methacetin and 13C-α-Ketoisocaproic Acid Breath Test

    PubMed Central

    Dänicke, Sven; Diers, Sonja

    2013-01-01

    Ergot alkaloids (the sum of individual ergot alkaloids are termed as total alkaloids, TA) are produced by the fungus Claviceps purpurea, which infests cereal grains commonly used as feedstuffs. Ergot alkaloids potentially modulate microsomal and mitochondrial hepatic enzymes. Thus, the aim of the present experiment was to assess their effects on microsomal and mitochondrial liver function using the 13C-Methacetin (MC) and 13C-α-ketoisocaproic acid (KICA) breath test, respectively. Two ergot batches were mixed into piglet diets, resulting in 11 and 22 mg (Ergot 5-low and Ergot 5-high), 9 and 14 mg TA/kg (Ergot 15-low and Ergot 15-high) and compared to an ergot-free control group. Feed intake and live weight gain decreased significantly with the TA content (p < 0.001). Feeding the Ergot 5-high diet tended to decrease the 60-min-cumulative 13CO2 percentage of the dose recovery (cPDR60) by 26% and 28% in the MC and KICA breath test, respectively, compared to the control group (p = 0.065). Therefore, both microsomal and mitochondrial liver function was slightly affected by ergot alkaloids. PMID:23322130

  16. [Breath tests in children with suspected lactose intolerance].

    PubMed

    Parra, P Ángela; Furió, C Simone; Arancibia, A Gabriel

    2015-01-01

    Up to 70% of the world population is lactose intolerance. However, there are no epidemiological studies among Chilean pediatric population affected by this condition. Clinical characterization of a series of children who underwent the lactose intolerance breath test for lactose intolerance study, establishing intolerance and malabsorption frequencies, the most frequent symptoms, and test performance depending on the origin. Patients under 18 years old who took the lactose intolerance breath test in the Gastroenterology Laboratory of the Catholic University of Chile, and who were admitted due to clinically suspected lactose intolerance. Malabsorption was considered when there was as an increase of ≥20ppm above the baseline (H2) or ≥34ppm of H2 and methane (CH4) combined. Intolerance was considered when the above was associated with a symptom intensity score ≥7 during registration. The analysis included194 patients aged 1 to17 years of age. Of these, 102 (53%) presented with malabsorption, and 53 (27%) were intolerant. The frequency of lactose intolerance varied from 7.1 to 45.4%, and it occurred more frequently at older ages. The most common reported symptoms were abdominal pain, bloating and rumbling. Lactose malabsorption and intolerance can be investigated from the first years of life using the lactose breath test plus a symptom questionnaire. An increase in the frequency of intolerance with age, and a greater number of positive tests, if they were requested by a gastroenterologist, were observed. Copyright © 2015 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  18. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Are alcohol tests other than saliva or breath... Testing § 40.277 Are alcohol tests other than saliva or breath permitted under these regulations? No.... Only saliva or breath for screening tests and breath for confirmation tests using approved devices...

  19. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Noxious or offensive odor and oxygen percentage; (c) Each breathing supply system is checked, prior to... diver, for noxious or offensive odor and presence of oil mist; and (d) Each breathing supply system...

  20. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Noxious or offensive odor and oxygen percentage; (c) Each breathing supply system is checked, prior to... diver, for noxious or offensive odor and presence of oil mist; and (d) Each breathing supply system...

  1. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Noxious or offensive odor and oxygen percentage; (c) Each breathing supply system is checked, prior to... diver, for noxious or offensive odor and presence of oil mist; and (d) Each breathing supply system...

  2. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Noxious or offensive odor and oxygen percentage; (c) Each breathing supply system is checked, prior to... diver, for noxious or offensive odor and presence of oil mist; and (d) Each breathing supply system...

  3. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Noxious or offensive odor and oxygen percentage; (c) Each breathing supply system is checked, prior to... diver, for noxious or offensive odor and presence of oil mist; and (d) Each breathing supply system...

  4. A 20-minute breath test for helicobacter pylori

    SciTech Connect

    Marshall, B.J.; Plankey, M.W.; Hoffman, S.R.; Boyd, C.L.; Dye, K.R.; Frierson, H.F. Jr.; Guerrant, R.L.; McCallum, R.W. )

    1991-04-01

    In this study, we evaluated a simplified rapid {sup 14}C-urea breath test for the diagnosis of Helicobacter pylori. Fasting patients undergoing initial assessment for H. pylori drank 5 microCi of {sup 14}C-urea in 20 ml of water. Breath was collected at intervals for 30 min. Samples were counted in a beta-counter, and the results were expressed as counts per minute (cpm). In the same week, patients underwent endoscopy, and a blinded investigator examined biopsy samples of gastric mucosa by culture and histology for H. pylori. There were 49 H. pylori-negative (HP-) and 104 H. pylori-positive (HP+) patients in the study. HP+ patients expired a mean of 4398 cpm (SD 2468) per mmol CO{sub 2} in a sample taken 20 min after ingestion of the isotope. In contrast, HP--patients expired only 340 cpm (SD 196). If the mean +3 SD of HP- patients was used as a cutoff value, the 20-minute sample gave a sensitivity of 97% and a specificity of 100% for detecting H. pylori. The radiation exposure from this test is less than 1% of that received from an upper gastrointestinal series, and the short collection time makes it both convenient and cost effective.

  5. Walk test and school performance in mouth-breathing children.

    PubMed

    Boas, Ana Paula Dias Vilas; Marson, Fernando Augusto de Lima; Ribeiro, Maria Angela Gonçalves de Oliveira; Sakano, Eulália; Conti, Patricia Blau Margosian; Toro, Adyléia Dalbo Contrera; Ribeiro, José Dirceu

    2013-01-01

    In recent decades, many studies on mouth breathing (MB) have been published; however, little is known about many aspects of this syndrome, including severity, impact on physical and academic performances. Compare the physical performance in a six minutes walk test (6MWT) and the academic performance of MB and nasal-breathing (NB) children and adolescents. This is a descriptive, cross-sectional, and prospective study with MB and NB children submitted to the 6MWT and scholar performance assessment. We included 156 children, 87 girls (60 NB and 27 MB) and 69 boys (44 NB and 25 MB). Variables were analyzed during the 6MWT: heart rate (HR), respiratory rate, oxygen saturation, distance walked in six minutes and modified Borg scale. All the variables studied were statistically different between groups NB and MB, with the exception of school performance and HR in 6MWT. MB affects physical performance and not the academic performance, we noticed a changed pattern in the 6MWT in the MB group. Since the MBs in our study were classified as non-severe, other studies comparing the academic performance variables and 6MWT are needed to better understand the process of physical and academic performances in MB children.

  6. Exhaled breath for drugs of abuse testing - evaluation in criminal justice settings.

    PubMed

    Beck, Olof

    2014-01-01

    Exhaled breath is being developed as a possible specimen for drug testing based on the collection of aerosol particles originating from the lung fluid. The present study was aimed to evaluate the applicability of exhaled breath for drugs of abuse testing in criminal justice settings. Particles in exhaled breath were collected with a new device in parallel with routine urine testing in two Swedish prisons, comprising both genders. Urine screening was performed according to established routines either by dipstick or by immunochemical methods at the Forensic Chemistry Laboratory and confirmations were with mass spectrometry methods. A total of 247 parallel samples were studied. Analysis of exhaled breath samples was done with a sensitive mass spectrometric method and identifications were made according to forensic standards. In addition tested subjects and personnel were asked to fill in a questionnaire concerning their views about drug testing. In 212 cases both the urine and breath testing were negative, and in 22 cases both urine and breath were positive. Out of 6 cases where breath was negative and urine positive 4 concerned THC. Out of 7 cases where, breath was positive and urine negative 6 concerned amphetamine. Detected substances in breath comprised: amphetamine, methamphetamine, THC, methylphenidate, buprenorphine, 6-acetylmorphine, cocaine, benzoylecgonine, diazepam and tramadol. Both the prison inmates and staff members reported breath testing to be preferable due to practical considerations. The results of this study documented that drug testing using exhaled breath provided as many positives as urine testing despite an expected shorter detection window, and that the breath sampling procedure was well accepted and provided practical benefits reported both by the prison inmates and testing personnel.

  7. Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

    PubMed

    Keiner, Robert; Gruselle, Marie-Cécile; Michalzik, Beate; Popp, Jürgen; Frosch, Torsten

    2015-03-01

    An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L. (European beech) seedlings with (13)CO2. The rapid monitoring of all these gases simultaneously allowed for the separation of photosynthetic uptake of CO2 by the beech seedlings and a constant (12)CO2 efflux via respiration and thus for a correction of the measured (12)CO2 concentrations in course of the labeling experiment. The effects of aphid infestation with the woolly beech aphid (Phyllaphis fagi L.) as well as the effect of a drought period on the respirational gas exchange were investigated. A slightly decreased respirational activity of drought-stressed seedlings in comparison to normally watered seedlings was found already for a low drought intensity. Cavity-enhanced Raman gas monitoring of O2, (12)CO2, and (13)CO2 was proven to be a powerful new tool for studying the effect of drought stress and aphid infestation on the respirational activity of European beech seedlings as an example of important forest species in Central Europe.

  8. (13) CO2 /(12) CO2 exchange fluxes in a clamp-on leaf cuvette: disentangling artefacts and flux components.

    PubMed

    Gong, Xiao Ying; Schäufele, Rudi; Feneis, Wolfgang; Schnyder, Hans

    2015-11-01

    Leaks and isotopic disequilibria represent potential errors and artefacts during combined measurements of gas exchange and carbon isotope discrimination (Δ). This paper presents new protocols to quantify, minimize, and correct such phenomena. We performed experiments with gradients of CO2 concentration (up to ±250 μmol mol(-1) ) and δ(13) CCO2 (34‰), between a clamp-on leaf cuvette (LI-6400) and surrounding air, to assess (1) leak coefficients for CO2 , (12) CO2 , and (13) CO2 with the empty cuvette and with intact leaves of Holcus lanatus (C3 ) or Sorghum bicolor (C4 ) in the cuvette; and (2) isotopic disequilibria between net photosynthesis and dark respiration in light. Leak coefficients were virtually identical for (12) CO2 and (13) CO2 , but ∼8 times higher with leaves in the cuvette. Leaks generated errors on Δ up to 6‰ for H. lanatus and 2‰ for S. bicolor in full light; isotopic disequilibria produced similar variation of Δ. Leak errors in Δ in darkness were much larger due to small biological : leak flux ratios. Leak artefacts were fully corrected with leak coefficients determined on the same leaves as Δ measurements. Analysis of isotopic disequilibria enabled partitioning of net photosynthesis and dark respiration, and indicated inhibitions of dark respiration in full light (H. lanatus: 14%, S. bicolor: 58%). © 2015 John Wiley & Sons Ltd.

  9. Application of drug testing using exhaled breath for compliance monitoring of drug addicts in treatment.

    PubMed

    Carlsson, Sten; Olsson, Robert; Lindkvist, Irene; Beck, Olof

    2015-04-01

    Exhaled breath has recently been identified as a possible matrix for drug testing. This study explored the potential of this new method for compliance monitoring of patients being treated for dependence disorders. Outpatients in treatment programs were recruited for this study. Urine was collected as part of clinical routine and a breath sample was collected in parallel together with a questionnaire about their views of the testing procedure. Urine was analyzed for amphetamines, benzodiazepines, cannabis, cocaine, buprenorphine, methadone and opiates using CEDIA immunochemical screening and mass spectrometry confirmation. The exhaled breath was collected using the SensAbues device and analyzed by mass spectrometry for amphetamine, methamphetamine, diazepam, oxazepam, tetrahydrocannabinol, cocaine, benzoylecgonine, buprenorphine, methadone, morphine, codeine and 6-acetylmorphine. A total of 122 cases with parallel urine and breath samples were collected; 34 of these were negative both in urine and breath. Out of 88 cases with positive urine samples 51 (58%) were also positive in breath. Among the patients on methadone treatment, all were positive for methadone in urine and 83% were positive in breath. Among patients in treatment with buprenorphine, 92% were positive in urine and among those 80% were also positive in breath. The questionnaire response documented that in general, patients accepted drug testing well and that the breath sampling procedure was preferred. Compliance testing for the intake of prescribed and unprescribed drugs among patients in treatment for dependence disorders using the exhaled breath sampling technique is a viable method and deserves future attention.

  10. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Conducting an initial test for alcohol using a breath specimen. 26.95 Section 26.95 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The...

  11. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Conducting an initial test for alcohol using a breath specimen. 26.95 Section 26.95 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The...

  12. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Conducting an initial test for alcohol using a breath specimen. 26.95 Section 26.95 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The...

  13. Automatisation of the single-breath nitrogen washout test.

    PubMed

    Melo, M F; Giannella Neto, A

    1989-03-01

    The paper presents a computer-based system for performance and analysis of the single-breath nitrogen washout test (Sb-N2 test). A pneumotachometer and a rapid gas analyser are used for volume flow rate and nitrogen fraction measurements. The data are acquired and analysed by a PDP-11/34 computer. Several sources of measurement errors are considered. An algorithm is proposed to reduce errors in flow measurements due to viscosity variation in respired air. The algorithm for closing volume (CV) detection and calculation of other Sb-N2 parameters is developed from 50 tracings of 18 subjects. The CV is obtained by an iterative linear fitting of the later half of the Sb-N2 curve. Comparisons between computer and hand measurements of three trained readers show good correlations (r = 0.87, 0.93, 0.91). The variability of computer CV measurements was comparable with that of the hand reader with the lowest variance. The coefficient of variation of residual volume and slope of alveolar plateau measurements are apparently reduced. The results demonstrate the adequacy and convenience of using the computer to analyse the Sb-N2 test and indicate that the automation allows for reduction of experimental errors and of test parameter variabilities.

  14. Aspiration tests in aqueous foam using a breathing simulator

    SciTech Connect

    Archuleta, M.M.

    1995-12-01

    Non-toxic aqueous foams are being developed by Sandia National Laboratories (SNL) for the National Institute of Justice (NIJ) for use in crowd control, cell extractions, and group disturbances in the criminal justice prison systems. The potential for aspiration of aqueous foam during its use and the resulting adverse effects associated with complete immersion in aqueous foam is of major concern to the NIJ when examining the effectiveness and safety of using this technology as a Less-Than-Lethal weapon. This preliminary study was designed to evaluate the maximum quantity of foam that might be aspirated by an individual following total immersion in an SNL-developed aqueous foam. A.T.W. Reed Breathing simulator equipped with a 622 Silverman cam was used to simulate the aspiration of an ammonium laureth sulfate aqueous foam developed by SNL and generated at expansion ratios in the range of 500:1 to 1000:1. Although the natural instinct of an individual immersed in foam is to cover their nose and mouth with a hand or cloth, thus breaking the bubbles and decreasing the potential for aspiration, this study was performed to examine a worst case scenario where mouth breathing only was examined, and no attempt was made to block foam entry into the breathing port. Two breathing rates were examined: one that simulated a sedentary individual with a mean breathing rate of 6.27 breaths/minute, and one that simulated an agitated or heavily breathing individual with a mean breathing rate of 23.7 breaths/minute. The results of this study indicate that, if breathing in aqueous foam without movement, an air pocket forms around the nose and mouth within one minute of immersion.

  15. Influence of C4 vegetation on 13CO2 discrimination and isoforcing in the upper Midwest, United States

    NASA Astrophysics Data System (ADS)

    Griffis, T. J.; Baker, J. M.; Sargent, S. D.; Erickson, M.; Corcoran, J.; Chen, M.; Billmark, K.

    2010-12-01

    Agricultural crops with a C4 photosynthetic pathway rapidly expanded across North America as early as 800 A.D. Their distribution continues to expand globally as demands for food and biofuel production increase. These systems are highly productive, having a significant impact on carbon and water exchange between the land and atmosphere. Here, we investigate the relative impact of agricultural C4 vegetation on the 13CO2 photosynthetic discrimination and atmospheric isotopic forcing in the upper Midwest, United States. We address three questions: (1) What is the relative importance of C3 and C4 species to the CO2 budget? (2) How do these different photosynthetic pathways influence the photosynthetic discrimination within this heterogeneous landscape? (3) To what extent does land use change (i.e., a change in C4 crops) impact atmospheric isotopic forcing and the isotopic signature of the atmosphere? These questions are addressed using measurements obtained from the University of Minnesota tall tower (244 m) trace gas observatory (TGO) over the growing seasons of 2007 and 2008 and are supported with scaled-up values of discrimination and isotopic forcing based on ecosystem-scale eddy flux observations and high-resolution land use data. Our land use analyses indicate that local and regional C4 production was higher by 10% in 2007 due to increased demand for biofuel. The 2007 growing season was also characterized by moderate drought as a consequence of low antecedent soil water content. Isotopic flux ratio measurements from TGO provide evidence that the increase in C4 land use and drier soil conditions of 2007 had a significant impact on the growing season 13CO2 photosynthetic discrimination, which ranged from 11.5 to 14.8 in 2007 and 12.4‰ to 17.4‰ in 2008. Isotopic partitioning indicated that C4 species accounted for about 20 to 40% of the growing season gross photosynthetic CO2 exchange. The isoforcing analysis revealed that C3 discrimination dominated the

  16. Operation and testing of Mark 10 Mod 3 underwater breathing apparatus

    NASA Technical Reports Server (NTRS)

    Milwee, W. I., Jr.

    1972-01-01

    Performance tests on a closed circuit, mixed gas underwater breathing apparatus are reported. The equipment is designed to provide a minimum diving duration of four hours at 1500 ft below sea surface; it senses oxygen partial pressure in the breathing gas mix and controls oxygen content of the breathing gas within narrow limits about a preset value. The breathing circuit subsystem provides respirable gas to the diver and removes carbon dioxide and moisture from the expired gas. Test results indicate undesirable variations in oxygen partial pressure with oxygen addition and insufficient carbon dioxide absorption.

  17. (13) C Breath Tests Are Feasible in Patients With Extracorporeal Membrane Oxygenation Devices.

    PubMed

    Bednarsch, Jan; Menk, Mario; Malinowski, Maciej; Weber-Carstens, Steffen; Pratschke, Johann; Stockmann, Martin

    2016-07-01

    Temporary extracorporeal membrane oxygenation (ECMO) has been established as an essential part of therapy in patients with pulmonary or cardiac failure. As physiological gaseous exchange is artificially altered in this patient group, it is debatable whether a (13) C-breath test can be carried out. In this proof of technical feasibility report, we assess the viability of the (13) C-breath test LiMAx (maximum liver function capacity) in patients on ECMO therapy. All breath probes for the test device were obtained directly via the membrane oxygenator. Data of four patients receiving liver function assessment with the (13) C-breath test LiMAx while having ECMO therapy were analyzed. All results were compared with validated scenarios of the testing procedures. The LiMAx test could successfully be carried out in every case without changing ECMO settings. Clinical course of the patients ranging from multiorgan failure to no sign of liver insufficiency was in accordance with the results of the LiMAx liver function test. The (13) C-breath test is technically feasible in the context of ECMO. Further evaluation of (13) C-breath test in general would be worthwhile. The LiMAx test as a (13) C-breath test accessing liver function might be of particular predictive interest if patients with ECMO therapy develop multiorgan failure.

  18. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  19. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  20. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  1. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  2. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of...

  3. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... extraction test to determine alcohol or other drug concentration or presence under this part. (3) May be given breath or urine tests, or both. (e) If a person suspected of intoxicated driving refuses to submit...

  4. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... extraction test to determine alcohol or other drug concentration or presence under this part. (3) May be given breath or urine tests, or both. (e) If a person suspected of intoxicated driving refuses to submit...

  5. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... extraction test to determine alcohol or other drug concentration or presence under this part. (3) May be given breath or urine tests, or both. (e) If a person suspected of intoxicated driving refuses to submit...

  6. Protection Factor Testing of the 3M Breathe Easy (BE-10) Powered Air Purifying Respirator (PAPR)

    DTIC Science & Technology

    2003-09-01

    This report describes the results of the performance testing of the 3M Breathe Easy (BE-10) Powered Air Purifying Respirator. A series of tests were performed to determine the corn -oil protection factors using human subjects.

  7. Failure of the hydrogen breath test to detect pulmonary sugar malabsorption.

    PubMed

    Gardiner, A J; Tarlow, M J; Symonds, J; Hutchison, J G; Sutherland, I T

    1981-05-01

    Five patients with sucrase-isomaltase deficiency, and one patient with primary glucose-galactose malabsorption had no increases in breath hydrogen excretion after oral sucrose or glucose. Anaerobic incubation with sugars of stool suspensions from 5 patients with primary sugar malabsorption produced by trace of hydrogen (17 microliter) in only one, while those from 13 or 14 controls produced a mean hydrogen volume of 640 microliter under similar conditions. Altered bacterial metabolism is a probable explanation. Breath hydrogen excretion did increase appreciably in 2 of these patients after oral lactulose showing that hydrogen excretion may vary according to the substrate. Therefore, observation of breath hydrogen excretion after lactulose is not recommended as a means of predicting false-negative breath tests with other sugars. The hydrogen breath test is not a reliable mean of diagnosing primary sugar malabsorption in children.

  8. Breath hydrogen test in infants and children with blind loop syndrome.

    PubMed

    Nose, O; Kai, H; Harada, T; Ogawa, M; Maki, I; Tajiri, H; Kanaya, S; Kimura, S; Shimizu, K; Yabuuchi, H

    1984-06-01

    Breath hydrogen production after oral lactose loading was examined in infants and children with stagnant loop syndrome, blind loop syndrome, or both. All six infants under 3 years of age had bacteriological evidence of small intestinal colonization. The characteristics of the breath hydrogen test in this syndrome are: (a) extremely high basal excretion of breath hydrogen (after overnight fasting); (b) an earlier and greater breath hydrogen value (0.293 +/- 0.201 ml/min/m2: mean +/- SD) after oral lactose administration than formed in lactose malabsorption alone (0.050 +/- 0.041 ml/min/m2); and (c) the observation of a sustained hydrogen rise over several hours. This investigation demonstrated that the breath hydrogen test is a promising and noninvasive tool for diagnosing blind (or stagnant) loop syndrome.

  9. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    NASA Astrophysics Data System (ADS)

    Epron, D.; Ngao, J.; Dannoura, M.; Bakker, M. R.; Zeller, B.; Bazot, S.; Bosc, A.; Plain, C.; Lata, J. C.; Priault, P.; Barthes, L.; Loustau, D.

    2011-05-01

    Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objective of our study was to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine) was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tuneable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C) of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6-2.7 days during the active growing season, more than 4 days during the resting season), and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. It varied between 1 and 21 % of the amount of 13CO2 taken up by the crown, depending on the species and the season. While rainfall exclusion that moderately decreased soil water content did not affect the pattern of carbon allocation to soil CO2 efflux in beech, seasonal patterns of carbon allocation belowground differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with the strength of other sinks (aboveground growth in late spring and storage in late summer) that were not observed in oak. We report a fast transfer of recent photosynthates to the mycorhizosphere and we conclude that the patterns of carbon

  10. Reliability of breath by breath spirometry and relative flow-time indices for pulmonary function testing in horses.

    PubMed

    Burnheim, K; Hughes, K J; Evans, D L; Raidal, S L

    2016-11-28

    Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO2)-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter. The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO2, but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration. The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing.

  11. The [(13)c]glucose breath test is a reliable method to identify insulin resistance in Mexican adults without diabetes: comparison with other insulin resistance surrogates.

    PubMed

    Maldonado-Hernández, Jorge; Martínez-Basila, Azucena; Matute-González, María Guadalupe; López-Alarcón, Mardia

    2014-06-01

    Insulin resistance (IR) precedes type 2 diabetes, but tests used to detect it in clinical settings reported poor reproducibility. We assessed the reliability of the [(13)C]glucose breath test ((13)C-GBT) in a sample of subjects without diabetes. Repeatability of the test was compared with that of other IR surrogates derived from the fasting or oral glucose tolerance test (OGTT). Eighty-six healthy volunteers received an oral load of 75 g of glucose in 150 mL of water followed by 1.5 mg/kg of [U-(13)C]glucose in 50 mL of water. Breath and blood samples were collected at baseline and at 10, 20, 30, 60, 90, 120, 150, and 180 min following the glucose load; the same procedure was repeated within 1 week. The enrichment of breath (13)CO2 was measured by ratio mass spectrometry and expressed as percentage oxidized dose at a given time period. Intrasubject variability was assessed with Bland-Altman plots and coefficients of variation (CVs). The overall CV of the (13)C-GBT was 12.99±11.61%, compared with 18.42% of fasting insulin, 19.44% for homeostasis model assessment, 17.06% of the composite insulin sensitivity index, and 29.99% for insulin in the 2-h oral glucose tolerance test. The variability of the (13)C-GBT tended to be higher in lean (17.40%) than in overweight (10.17%) and obese (12.61%) individuals. The variability of the (13)C-GBT is lower than that of other IR surrogates, making it a reproducible method to estimate insulin sensitivity in overweight and obese adults without diabetes. Because the individuals did not have diabetes but were within a high range of insulin sensitivity, the test should have application in clinical and population-based studies, given the evidence for the utility and limitations of this surrogate.

  12. Unraveling carbohydrate transport mechanisms in young beech trees (Fagus sylvatica f. purpurea) by 13CO2 efflux measurements from stem and soil

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Muhr, Jan; Keitel, Claudia; Kayler, Zachary; Gavrichkova, Olga; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2016-04-01

    Transport mechanisms of soluble carbohydrates and diurnal CO2 efflux from tree stems and surrounding soil are well studied. However, the effect of transport carbohydrates on respiration and their interaction with storage processes is largely unknown. Therefore, we performed a set of 13CO2 pulse labeling experiments on young trees of European beech (Fagus sylvatica f. purpurea). We labeled the whole tree crowns in a closed transparent plastic chamber with 99% 13CO2 for 30 min. In one experiment, only a single branch was labeled and removed 36 hours after labeling. In all experiments, we continuously measured the 13CO2 efflux from stem, branch and soil and sampled leaf and stem material every 3 h for 2 days, followed by a daily sampling of leaves in the successive 5 days. The compound specific δ 13C value of extracted soluble carbohydrates from leaf and stem material was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). The 13CO2 signal from soil respiration occurred only few hours after labeling indicating a very high transport rate of carbohydrates from leaf to roots and to the rhizosphere. The label was continuously depleted within the next 5 days. In contrast, we observed a remarkable oscillating pattern of 13CO2 efflux from the stem with maximum 13CO2 enrichment at noon and minima at night time. This oscillation suggests that enriched carbohydrates are respired during the day, whereas in the night the enriched sugars are not respired. The observed oscillation in stem 13CO2 enrichment remained unchanged even when only single branches were labelled and cut right afterwards. Thus, storage and conversion of carbohydrates only occurred within the stem. The δ13C patterns of extracted soluble carbohydrates showed, that a transformation of transitory starch to carbohydrates and vice versa was no driver of the oscillating 13CO2 efflux from the stem. Carbohydrates might have been transported in the phloem to

  13. Origin of monoterpene emissions from boreal tree species: Determination of de novo and pool emissions by 13CO2 labeling

    NASA Astrophysics Data System (ADS)

    Rinne, J.; Ghirardo, A.; Koch, K.; Taipale, R.; Zimmer, I.; Schnitzler, J.

    2009-12-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS we studied the origin of monoterpene emissions from some major Eurasian boreal and alpine tree species. We determined the fractions originating from de novo biosynthesis and from large internal monoterpene storages for three coniferous tree species with specialized monoterpene storage structures and one dicotyledon species without such structures. The emission from dicotyledon species Betula pendula originated solely from the de novo synthesis. The origin of the emissions from coniferous species was mixed with varying fraction originating from de novo synthesis (Pinus sylvestris 58%, Picea abies 33.5%, Larix decidua 9.8%) and the rest from large internal monoterpene storage pools. Application of the observed fractions of emission originating from de novo synthesis and large storage pools in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand.

  14. 13C Tracking after 13CO2 Supply Revealed Diurnal Patterns of Wood Formation in Aspen1

    PubMed Central

    Mahboubi, Amir; Linden, Pernilla; Moritz, Thomas

    2015-01-01

    Wood of trees is formed from carbon assimilated in the photosynthetic tissues. Determining the temporal dynamics of carbon assimilation, subsequent transport into developing wood, and incorporation to cell walls would further our understanding of wood formation in particular and tree growth in general. To investigate these questions, we designed a 13CO2 labeling system to study carbon transport and incorporation to developing wood of hybrid aspen (Populus tremula × tremuloides). Tracking of 13C incorporation to wood over a time course using nuclear magnetic resonance spectroscopy revealed diurnal patterns in wood cell wall biosynthesis. The dark period had a differential effect on 13C incorporation to lignin and cell wall carbohydrates. No 13C was incorporated into aromatic amino acids of cell wall proteins in the dark, suggesting that cell wall protein biosynthesis ceased during the night. The results show previously unrecognized temporal patterns in wood cell wall biosynthesis, suggest diurnal cycle as a possible cue in the regulation of carbon incorporation to wood, and establish a unique 13C labeling method for the analysis of wood formation and secondary growth in trees. PMID:25931520

  15. (13)C-Breath testing in animals: theory, applications, and future directions.

    PubMed

    McCue, Marshall D; Welch, Kenneth C

    2016-04-01

    The carbon isotope values in the exhaled breath of an animal mirror the carbon isotope values of the metabolic fuels being oxidized. The measurement of stable carbon isotopes in carbon dioxide is called (13)C-breath testing and offers a minimally invasive method to study substrate oxidation in vivo. (13)C-breath testing has been broadly used to study human exercise, nutrition, and pathologies since the 1970s. Owing to reduced use of radioactive isotopes and the increased convenience and affordability of (13)C-analyzers, the past decade has witnessed a sharp increase in the use of breath testing throughout comparative physiology--especially to answer questions about how and when animals oxidize particular nutrients. Here, we review the practical aspects of (13)C-breath testing and identify the strengths and weaknesses of different methodological approaches including the use of natural abundance versus artificially-enriched (13)C tracers. We critically compare the information that can be obtained using different experimental protocols such as diet-switching versus fuel-switching. We also discuss several factors that should be considered when designing breath testing experiments including extrinsic versus intrinsic (13)C-labelling and different approaches to model nutrient oxidation. We use case studies to highlight the myriad applications of (13)C-breath testing in basic and clinical human studies as well as comparative studies of fuel use, energetics, and carbon turnover in multiple vertebrate and invertebrate groups. Lastly, we call for increased and rigorous use of (13)C-breath testing to explore a variety of new research areas and potentially answer long standing questions related to thermobiology, locomotion, and nutrition.

  16. Multiscale observations of CO2, 13CO2, and pollutants at Four Corners for emission verification and attribution.

    PubMed

    Lindenmaier, Rodica; Dubey, Manvendra K; Henderson, Bradley G; Butterfield, Zachary T; Herman, Jay R; Rahn, Thom; Lee, Sang-Hyun

    2014-06-10

    There is a pressing need to verify air pollutant and greenhouse gas emissions from anthropogenic fossil energy sources to enforce current and future regulations. We demonstrate the feasibility of using simultaneous remote sensing observations of column abundances of CO2, CO, and NO2 to inform and verify emission inventories. We report, to our knowledge, the first ever simultaneous column enhancements in CO2 (3-10 ppm) and NO2 (1-3 Dobson Units), and evidence of δ(13)CO2 depletion in an urban region with two large coal-fired power plants with distinct scrubbing technologies that have resulted in ∆NOx/∆CO2 emission ratios that differ by a factor of two. Ground-based total atmospheric column trace gas abundances change synchronously and correlate well with simultaneous in situ point measurements during plume interceptions. Emission ratios of ∆NOx/∆CO2 and ∆SO2/∆CO2 derived from in situ atmospheric observations agree with those reported by in-stack monitors. Forward simulations using in-stack emissions agree with remote column CO2 and NO2 plume observations after fine scale adjustments. Both observed and simulated column ∆NO2/∆CO2 ratios indicate that a large fraction (70-75%) of the region is polluted. We demonstrate that the column emission ratios of ∆NO2/∆CO2 can resolve changes from day-to-day variation in sources with distinct emission factors (clean and dirty power plants, urban, and fires). We apportion these sources by using NO2, SO2, and CO as signatures. Our high-frequency remote sensing observations of CO2 and coemitted pollutants offer promise for the verification of power plant emission factors and abatement technologies from ground and space.

  17. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    NASA Astrophysics Data System (ADS)

    Epron, D.; Ngao, J.; Dannoura, M.; Bakker, M. R.; Zeller, B.; Bazot, S.; Bosc, A.; Plain, C.; Lata, J. C.; Priault, P.; Barthes, L.; Loustau, D.

    2011-02-01

    Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objectives of our study were to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine) was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tunable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C) of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6-2.7 days during the active growing season, more than 4 days during the resting season), and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. Seasonal patterns of carbon allocation to soil CO2 efflux differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with other sinks (aboveground growth in late spring and storage in late summer) that were not observed in oak.

  18. Multiscale observations of CO2, 13CO2, and pollutants at Four Corners for emission verification and attribution

    PubMed Central

    Lindenmaier, Rodica; Dubey, Manvendra K.; Henderson, Bradley G.; Butterfield, Zachary T.; Herman, Jay R.; Rahn, Thom; Lee, Sang-Hyun

    2014-01-01

    There is a pressing need to verify air pollutant and greenhouse gas emissions from anthropogenic fossil energy sources to enforce current and future regulations. We demonstrate the feasibility of using simultaneous remote sensing observations of column abundances of CO2, CO, and NO2 to inform and verify emission inventories. We report, to our knowledge, the first ever simultaneous column enhancements in CO2 (3–10 ppm) and NO2 (1–3 Dobson Units), and evidence of δ13CO2 depletion in an urban region with two large coal-fired power plants with distinct scrubbing technologies that have resulted in ∆NOx/∆CO2 emission ratios that differ by a factor of two. Ground-based total atmospheric column trace gas abundances change synchronously and correlate well with simultaneous in situ point measurements during plume interceptions. Emission ratios of ∆NOx/∆CO2 and ∆SO2/∆CO2 derived from in situ atmospheric observations agree with those reported by in-stack monitors. Forward simulations using in-stack emissions agree with remote column CO2 and NO2 plume observations after fine scale adjustments. Both observed and simulated column ∆NO2/∆CO2 ratios indicate that a large fraction (70–75%) of the region is polluted. We demonstrate that the column emission ratios of ∆NO2/∆CO2 can resolve changes from day-to-day variation in sources with distinct emission factors (clean and dirty power plants, urban, and fires). We apportion these sources by using NO2, SO2, and CO as signatures. Our high-frequency remote sensing observations of CO2 and coemitted pollutants offer promise for the verification of power plant emission factors and abatement technologies from ground and space. PMID:24843169

  19. sup 14 C-urea breath test for the detection of Helicobacter pylori

    SciTech Connect

    Veldhuyzen van Zanten, S.J.; Tytgat, K.M.; Hollingsworth, J.; Jalali, S.; Rshid, F.A.; Bowen, B.M.; Goldie, J.; Goodacre, R.L.; Riddell, R.H.; Hunt, R.H. )

    1990-04-01

    The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests. We have developed a {sup 14}C-urea breath test which uses 5 microCi {sup 14}C with 50 mg nonradioactive urea. Breath samples are collected at baseline and every 30 min for 2 h. Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients. The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positive predictive value 93%, and negative predictive value 100%. Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled {sup 14}CO{sub 2} which correlated with histological improvement in gastritis. The {sup 14}C-urea breath test is a better gold standard for the detection of Helicobacter pylori than histology and/or culture.

  20. Time-course of cigarette smoke contamination of clinical hydrogen breath-analysis tests.

    PubMed

    Rosenthal, A; Solomons, N W

    1983-11-01

    The time-course of the contamination of exogenous hydrogen from cigarette smoke on postprandial breath hydrogen concentration was evaluated in 10 subjects, six regular smokers and four occasional smokers. Breath hydrogen values were determined by gas chromatography 10 min, 5 min, and immediately prior to smoking a filter cigarette; during smoking from a sample of exhaled air containing smoke; and 5, 10, and 15 min after extinguishing the cigarette. A three- to 137-fold increase above basal hydrogen concentrations was produced by exhaled cigarette smoke, but most subjects had re-equilibrated to baseline values within 10 to 15 min after the cigarette. If subjects undergoing clinical hydrogen breath tests cannot refrain from smoking during the duration of the test, one should allow an interval of at least 15 min from the end of smoking to the collection of a breath sample.

  1. The Effectiveness of Daily Mindful Breathing Practices on Test Anxiety of Students

    PubMed Central

    Cho, Hyunju; Ryu, Seokjin; Noh, Jeeae; Lee, Jongsun

    2016-01-01

    The present study examined the effectiveness of daily mindful breathing practices on test anxiety of university students. A total of 36 participants were randomly assigned to one of three conditions: a training mindful breathing condition (n = 12), a training cognitive reappraisal condition (contrast group, n = 12), and a non-training condition (control group, n = 12). Each of the participants trained by themselves for 6 days after they had taken one session of education for mindful or cognitive reappraisal practices. They wrote their experiences on daily worksheets and sent it by mobile with taking pictures that were confirmed by the researcher. Before and after training, each of the participants completed a questionnaire to assess: test anxiety, positive thought, and positive affect. The results of the study showed that both mindful breathing practice and cognitive reappraisal practice yielded large effect sizes in reducing test anxiety. In addition, the mindful breathing condition scored significantly higher on positive thoughts than the cognitive reappraisal and control conditions. The findings of this study suggest that both daily mindful breathing and cognitive reappraisal practices were effective in reducing test anxiety; however, mindful breathing increased positive automatic thoughts to a greater extent than cognitive reappraisal. PMID:27764151

  2. Can handling E85 motor fuel cause positive breath alcohol test results?

    PubMed

    Ran, Ran; Mullins, Michael E

    2013-09-01

    Hand-held breath alcohol analyzers are widely used by police in traffic stops of drivers suspected of driving while intoxicated (DWI). E85 is a motor fuel consisting of 85% ethanol and 15% gasoline or other hydrocarbons, and is available at nearly 2,600 stations in the USA. We sought to determine whether handling E85 fuel could produce measurable breath alcohol results using a hand-held analyzer and to see if this would be a plausible explanation for a positive breath alcohol test. Five healthy adult subjects dispensed or transferred 8 US gallons of E85 fuel in each of four scenarios. We measured breath alcohol concentration in g/210 L of exhaled breath using the BACTrack S50 at 0, 2, 4, 6, 8, 10, 15 and 20 min after each fuel-handling scenario. Most of the subjects had no detectable breath alcohol after handling E85 motor fuel. Transient elevations (0.02-0.04 g/210 L) in breath alcohol measurement occurred up to 6 min after handling E85 in a minority of subjects. We conclude that it is unlikely that handling E85 motor fuel would result in erroneous prosecution for DWI.

  3. Tricks for interpreting and making a good report on hydrogen and 13C breath tests.

    PubMed

    D'Angelo, G; Di Rienzo, T A; Scaldaferri, F; Del Zompo, F; Pizzoferrato, M; Lopetuso, L R; Laterza, L; Bruno, G; Petito, V; Campanale, M C; Cesario, V; Franceschi, F; Cammarota, G; Gaetani, E; Gasbarrini, A; Ojetti, V

    2013-01-01

    Breath tests (BT) represent a valid and non-invasive diagnostic tool in many gastroenterological disorders. Their wide diffusion is due to the low cost, simplicity and reproducibility and their common indications include diagnosis of carbohydrate malabsorption, Helicobacter pylori infection, small bowel bacterial overgrowth, gastric emptying time and orocaecal transit time. The review deals with key points on methodology, which would influence the correct interpretation of the test and on a correct report. While a clear guideline is available for lactose and glucose breath tests, no gold standard is available for Sorbitol, Fructose or other H2 BTs. Orocaecal transit time (OCTT) defined as time between assumption of 10 g lactulose and a peak > 10 ppm over the baseline value, is a well-defined breath test. The possible value of lactulose as a diagnostic test for the diagnosis of small bowel bacterial overgrowth is still under debate. Among (13)C breath test, the best and well characterized is represented by the urea breath test. Well-defined protocols are available also for other (13)C tests, although a reimbursement for these tests is still not available. Critical points in breath testing include the patient preparation for test, type of substrate utilized, reading machines, time between when the test is performed and when the test is processed. Another crucial point involves clinical conclusions coming from each test. For example, even if lactulose could be utilized for diagnosing small bowel bacterial overgrowth, this indication should be only secondary to orocaecal transit time, and added into notes, as clinical guidelines are still uncertain.

  4. Potential effect of alcohol content in energy drinks on breath alcohol testing.

    PubMed

    Lutmer, Brian; Zurfluh, Carol; Long, Christopher

    2009-04-01

    Since the advent of energy drinks in the U.S. marketplace, some defendants have claimed that positive breath alcohol test results have occurred due to the ingestion of non-alcoholic energy drinks. A variety of energy drinks were tested by gas chromatography and some 88.9% (24 of 27) were found to contain low concentrations of ethanol (5-230 mg/dL). Drinks were then consumed (24.6-32 oz) by volunteers to determine the extent of reaction that could be achieved on a portable breath-testing instrument. Eleven of 27 (40.7%) beverages gave positive results on a portable breath-testing instrument (0.006-0.015 g/210 L) when samples were taken within 1 min of the end of drinking. All tests taken by portable breath test, DataMaster, and Intox EC/IR II at least 15 min after the end of drinking resulted in alcohol-free readings (0.000 g/210 L). Affording subjects a minimum 15-min observation period prior to breath-alcohol testing eliminates the possibility that a small false-positive alcohol reading will be obtained.

  5. The relationship between aminopyrine breath test and severity of liver disease in cirrhosis

    SciTech Connect

    Morelli, A.; Narducci, F.; Pelli, M.A.; Farroni, F.; Vedovelli, A.

    1981-08-01

    Twenty-two patients with cirrhosis were evaluated by the 2 hr.-(C14)-aminopyrine breath test, the conventional liver tests and two systems for grading the severity of liver disease. Twenty-three patients with noncirrhotic liver disease and 15 controls were also studied. Reduced 14CO2 values were found in 21 of the 22 cirrhotic patients and seven of those had noncirrhotic liver disease associated with severe functional reserve impairment. The values in patients with minor liver diseases or cholestasis were normal. In the cirrhotic patients 2 hr.-(C14)-aminopyrine breath test scores correlated with prothrombin time, retention of bromosulfalein, fasting serum bile acid, albumin, bilirubin, serum aspartate aminotransferase and, above all, with the scores of the two clinical rating systems. The 2 hr.-(C14)-aminopyrine breath test was superior to conventional tests in quantifying the degree of hepatic functional reserve and forecasting the prognosis.

  6. Short-term Fate of Carbon in two Woody Species Under Contrasting Resources Availability: Insights From a 13CO2 Pulse Labeling Approach

    NASA Astrophysics Data System (ADS)

    Mambelli, S.; Dawson, T. E.; Bird, J. A.; Torn, M. S.; Gaudinski, J. B.

    2003-12-01

    In response to the environment, plants adjust allocation patterns to maintain a functional balance between the activities of roots and shoots such that belowground resources are acquired in approximate balance with aboveground resources. Changes in allocation driven by changes in environmental conditions may affect the amount of carbon stored in plant tissues, released by the root system, and ultimately sequestered into the soil. The aim of this study was to quantify the allocation belowground of recently fixed carbon in contrasting species and resources availability. We tested the hypothesis that carbon limitation and high nitrogen supply both negatively affect carbon transport to roots, causing a reduction of the carbon flow into the soil rhizosphere. Two woody species, a conifer (Pinus Ponderosa) and a deciduous tree (Acer Rubrum) were grown in a greenhouse under a factorial of light and nitrogen regimes (full light/shade and limited/excess nitrogen). At the stage of full leaf expansion plants were pulse-labeled by addition of 13CO2 and harvested after 0, 7 and 30 days. During the experiment the treatments affected the pattern of plant biomass allocation. Shade negatively influenced belowground growth and Maple showed a more conservative response than Pine. High supply of nitrogen also reduced allocation to roots but only when plants were grown under light. Preliminary results show that the initial amount of recently fixed carbon into the rhizosphere was in general higher under Pine. However, after 7 and 30 days, the new soil carbon pool increased only in the rhizosphere of carbon limited Pine seedlings. These findings suggest that belowground respiration was negatively affected or, alternatively, that the exudates released were less easily decomposable

  7. Non-zero basal oxygen flow a hazard to anesthesia breathing circuit leak test.

    PubMed

    Tokumine, Joho; Sugahara, Kazuhiro; Gushiken, Kouji; Ohta, Minoru; Matsuyama, Tomoaki; Saikawa, Satoko

    2005-04-01

    The non-zero basal flow (BF) of oxygen in anesthesia machines has been set to supply the basal metabolic requirement of oxygen. However, there is no scientific evidence of its necessity. In this study we sought to clarify whether non-zero BF affects leak detection during preanesthetic inspections. Twenty-five participants performed leak tests on anesthesia machines to detect breathing circuit leaks. Artificial leak-producing devices were used to create leaks from 0 to 1.0 L/min. The investigator randomly chose the leak device and connected it into the breathing circuit. Participants, blinded as to the presence or the type of leak producing device, then tested the breathing circuit for leaks. The conventional breathing system leak test was performed with and without BF. The results of leak detection in each leak procedure were analyzed statistically. The leak detection rate of leak test with BF was less than without BF (P < 0.01). We demonstrated that non-zero BF of oxygen decreases the leak detection rate and is an obstacle for leak detection, especially for small leaks. Therefore, we recommend that breathing circuit leak tests should be performed in the absence of BF of oxygen.

  8. Fructose breath hydrogen test--is it really a harmless diagnostic procedure?

    PubMed

    Müller, P; Meier, C; Böhme, H J; Richter, T

    2003-01-01

    Usage of hydrogen breath tests has become one of the standard procedures in diagnosing chronic unspecific abdominal pain. These tests are said to be of sufficient specificity and sensitivity, are easily done, non-invasive and are more often practiced in outpatients. A 13-year-old boy is reported with chronic unspecific abdominal pain and growth retardation and so far misdiagnosed hereditary fructose intolerance (HFI), who developed life-threatening adverse effects during the fructose breath hydrogen test. It is concluded that the possibility of HFI should be excluded first by a carefully explored dietary history before the fructose breath test is performed under medical supervision. If there is any suspicion of HFI, a molecular genetic analysis should be preferred.

  9. ( sup 14 C)urea breath test for diagnosis of Helicobacter pylori

    SciTech Connect

    Ormand, J.E.; Talley, N.J.; Carpenter, H.A.; Shorter, R.G.; Conley, C.R.; Wilson, W.R.; DiMagno, E.P.; Zinsmeister, A.R.; Phillips, S.F. )

    1990-07-01

    H. pylori is a potent urease producer, a characteristic that has been exploited in the development of the (14C)- and (13C)urea breath tests. The prevalence of H. pylori infection also is known to increase with advancing age; however, the individual patient's age has not routinely been considered when interpreting urea breath test results. The aim of this study was to validate a short, age-adjusted (14C)urea breath test for use in diagnosing H. pylori infections. Forty-one subjects (28 volunteers, 13 patients) underwent esophagogastroduodenoscopy with biopsies. Subjects were defined as being H. pylori-positive if histology or culture was positive. In addition, all subjects completed a 120-min (14C)urea breath test. A logistic regression analysis adjusting for age was used to estimate the probability of H. pylori positivity as a function of the 14C values generated. Sixteen subjects were H. pylori-positive, and 25 were H. pylori-negative. The 14C values generated between 15 and 80 min were found to be equally predictive in identifying H. pylori-positive subjects. Advancing age was associated with a higher probability of H. pylori-positivity. By taking advantage of the statistical probabilities, older patients could be accurately diagnosed with H. pylori at lower 14C values. We found that (14C)urea breath test to be both a sensitive and specific test that can be abbreviated to a 30-min examination (total test time). Moreover, our mathematical model indicates that a patient's age should be considered in order to optimize interpretation of the (14C)urea breath test, although further observations are needed to confirm this model.

  10. Rapid Point-Of-Care Breath Test for Biomarkers of Breast Cancer and Abnormal Mammograms

    PubMed Central

    Phillips, Michael; Beatty, J. David; Cataneo, Renee N.; Huston, Jan; Kaplan, Peter D.; Lalisang, Roy I.; Lambin, Philippe; Lobbes, Marc B. I.; Mundada, Mayur; Pappas, Nadine; Patel, Urvish

    2014-01-01

    Background Previous studies have reported volatile organic compounds (VOCs) in breath as biomarkers of breast cancer and abnormal mammograms, apparently resulting from increased oxidative stress and cytochrome p450 induction. We evaluated a six-minute point-of-care breath test for VOC biomarkers in women screened for breast cancer at centers in the USA and the Netherlands. Methods 244 women had a screening mammogram (93/37 normal/abnormal) or a breast biopsy (cancer/no cancer 35/79). A mobile point-of-care system collected and concentrated breath and air VOCs for analysis with gas chromatography and surface acoustic wave detection. Chromatograms were segmented into a time series of alveolar gradients (breath minus room air). Segmental alveolar gradients were ranked as candidate biomarkers by C-statistic value (area under curve [AUC] of receiver operating characteristic [ROC] curve). Multivariate predictive algorithms were constructed employing significant biomarkers identified with multiple Monte Carlo simulations and cross validated with a leave-one-out (LOO) procedure. Results Performance of breath biomarker algorithms was determined in three groups: breast cancer on biopsy versus normal screening mammograms (81.8% sensitivity, 70.0% specificity, accuracy 79% (73% on LOO) [C-statistic value], negative predictive value 99.9%); normal versus abnormal screening mammograms (86.5% sensitivity, 66.7% specificity, accuracy 83%, 62% on LOO); and cancer versus no cancer on breast biopsy (75.8% sensitivity, 74.0% specificity, accuracy 78%, 67% on LOO). Conclusions A pilot study of a six-minute point-of-care breath test for volatile biomarkers accurately identified women with breast cancer and with abnormal mammograms. Breath testing could potentially reduce the number of needless mammograms without loss of diagnostic sensitivity. PMID:24599224

  11. Photoacoustic sensor for VOCs: first step towards a lung cancer breath test

    NASA Astrophysics Data System (ADS)

    Wolff, Marcus; Groninga, Hinrich G.; Dressler, Matthias; Harde, Hermann

    2005-08-01

    Development of new optical sensor technologies has a major impact on the progression of diagnostic methods. Specifically, the optical analysis of breath is an extraordinarily promising technique. Spectroscopic sensors for the non-invasive 13C-breath tests (the Urea Breath Test for detection of Helicobacter pylori is most prominent) are meanwhile well established. However, recent research and development go beyond gastroenterological applications. Sensitive and selective detection of certain volatile organic compounds (VOCs) in a patient's breath, could enable the diagnosis of diseases that are very difficult to diagnose with contemporary techniques. For instance, an appropriate VOC biomarker for early-stage bronchial carcinoma (lung cancer) is n-butane (C4H10). We present a new optical detection scheme for VOCs that employs an especially compact and simple set-up based on photoacoustic spectroscopy (PAS). This method makes use of the transformation of absorbed modulated radiation into a sound wave. Employing a wavelength-modulated distributed feedback (DFB) diode laser and taking advantage of acoustical resonances of the sample cell, we performed very sensitive and selective measurements on butane. A detection limit for butane in air in the ppb range was achieved. In subsequent research the sensitivity will be successively improved to match the requirements of the medical application. Upon optimization, our photoacoustic sensor has the potential to enable future breath tests for early-stage lung cancer diagnostics.

  12. Poor reproducibility of breath hydrogen testing: Implications for its application in functional bowel disorders

    PubMed Central

    Tuck, Caroline J; Barrett, Jacqueline S; Canale, Kim EK; Philpott, Hamish L; Gibson, Peter R

    2016-01-01

    Background Limited data are available regarding the reproducibility of lactulose and fructose breath testing for clinical application in functional bowel disorders. Objectives The purpose of this study was to investigate the reproducibility of lactulose and fructose breath hydrogen testing and assess symptom response to fructose testing. Methods Results were analysed from 21 patients with functional bowel disorder with lactulose breath tests and 30 with fructose breath tests who completed another test >2 weeks later. Oro-caecal transit time, hydrogen responses, both qualitatively (positive/negative) and quantitatively (area under the curve (AUC) for hydrogen), were compared between tests. In another 36 patients, data scores for overall abdominal symptoms, abdominal pain, bloating, wind, nausea and fatigue were collected during the fructose test and compared to hydrogen responses. Results No correlations were found for lactulose AUC (linear regression, p = 0.58) or transit time (Spearman's p = 0.54) between tests. A significant proportion (30%) lost the presence of fructose malabsorption (p < 0.01). Hydrogen AUC for fructose did not correlate between tests, (r = 0.28, p = 0.17) independent of time between testing (p = 0.82). Whilst patients with fructose malabsorption were more likely to report symptoms than those without (56% vs 17%; p = 0.04), changes in symptom severity were not different (p > 0.05). Conclusions Routine use of lactulose and fructose breath tests in functional bowel disorder patients is not supported due to its poor reproducibility and low predictive value for symptom responses.

  13. Carbon Monoxide in Exhaled Breath Testing and Therapeutics

    PubMed Central

    Ryter, Stefan W.; Choi, Augustine M.K.

    2013-01-01

    Carbon monoxide (CO), a low molecular weight gas, is a ubiquitous environmental product of organic combustion, which is also produced endogenously in the body, as the byproduct of heme metabolism. CO binds to hemoglobin, resulting in decreased oxygen delivery to bodily tissues at toxicological concentrations. At physiological concentrations, CO may have endogenous roles as a potential signaling mediator in vascular function and cellular homeostasis. Exhaled CO (eCO), similar to exhaled nitric oxide (eNO), has been evaluated as a candidate breath biomarker of pathophysiological states, including smoking status, and inflammatory diseases of the lung and other organs. eCO values have been evaluated as potential indicators of inflammation in asthma, stable COPD and exacerbations, cystic fibrosis, lung cancer, or during surgery or critical care. The utility of eCO as a marker of inflammation, and potential diagnostic value remains incompletely characterized. Among other candidate “medicinal gases” with therapeutic potential, (e.g., NO and H2S), CO has been shown to act as an effective anti-inflammatory agent in preclinical animal models of inflammatory disease, acute lung injury, sepsis, ischemia/reperfusion injury and organ graft rejection. Current and future clinical trials will evaluate the clinical applicability of this gas as a biomarker and/or therapeutic in human disease. PMID:23446063

  14. Use of the single-breath method of estimating cardiac output during exercise-stress testing.

    NASA Technical Reports Server (NTRS)

    Buderer, M. C.; Rummel, J. A.; Sawin, C. F.; Mauldin, D. G.

    1973-01-01

    The single-breath cardiac output measurement technique of Kim et al. (1966) has been modified for use in obtaining cardiac output measurements during exercise-stress tests on Apollo astronauts. The modifications involve the use of a respiratory mass spectrometer for data acquisition and a digital computer program for data analysis. The variation of the modified method for triplicate steady-state cardiac output measurements was plus or minus 1 liter/min. The combined physiological and methodological variation seen during a set of three exercise tests on a series of subjects was 1 to 2.5 liter/min. Comparison of the modified method with the direct Fick technique showed that although the single-breath values were consistently low, the scatter of data was small and the correlation between the two methods was high. Possible reasons for the low single-breath cardiac output values are discussed.

  15. Use of the single-breath method of estimating cardiac output during exercise-stress testing.

    NASA Technical Reports Server (NTRS)

    Buderer, M. C.; Rummel, J. A.; Sawin, C. F.; Mauldin, D. G.

    1973-01-01

    The single-breath cardiac output measurement technique of Kim et al. (1966) has been modified for use in obtaining cardiac output measurements during exercise-stress tests on Apollo astronauts. The modifications involve the use of a respiratory mass spectrometer for data acquisition and a digital computer program for data analysis. The variation of the modified method for triplicate steady-state cardiac output measurements was plus or minus 1 liter/min. The combined physiological and methodological variation seen during a set of three exercise tests on a series of subjects was 1 to 2.5 liter/min. Comparison of the modified method with the direct Fick technique showed that although the single-breath values were consistently low, the scatter of data was small and the correlation between the two methods was high. Possible reasons for the low single-breath cardiac output values are discussed.

  16. Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.

    1975-01-01

    The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

  17. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    PubMed Central

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-01-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange. PMID:27311826

  18. FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests

    NASA Astrophysics Data System (ADS)

    Sukul, Pritam; Schubert, Jochen K.; Oertel, Peter; Kamysek, Svend; Taunk, Khushman; Trefz, Phillip; Miekisch, Wolfram

    2016-06-01

    Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange.

  19. Hydrogen breath test for diagnosis of lactose malabsorption: The importance of timing and the number of breath samples

    PubMed Central

    Di Camillo, Mauro; Marinaro, Vanessa; Argnani, Fiorenza; Foglietta, Tiziana; Vernia, Piero

    2006-01-01

    BACKGROUND: The hydrogen breath test (H2BT) is the most widely used procedure in the diagnostic workup of lactose malabsorption and lactose intolerance. AIM: To establish whether a simplified two-or three-sample test may reduce time, costs and staff resources without reducing the sensitivity of the procedure. PATIENTS AND METHODS: Data from 1112 patients (292 men, 820 women) with a positive 4 h, nine-sample H2BT were retrospectively analyzed. Patients were stratified according to the degree of lactose malabsorption, the occurrence and type of symptoms. Loss of sensitivity in the procedure was evaluated taking into account two-sample tests (0 min and 120 min or 0 min and 210 min) or three-sample tests (0 min, 120 min and 180 min or 0 min, 120 min and 210 min). RESULTS: Using a two-sample test (0 min and 120 min or 0 min and 210 min) the false-negative rate was 33.4% and 22.7%, respectively. With a three-sample test (0 min, 120 min and 180 min or 0 min, 120 min or 210 min), lactose malabsorption was diagnosed in 91.2% (1014 of 1112) patients and in 96.1% (1068 of 1112) patients, respectively. Of 594 patients with abdominal symptoms, 158 (26.6%) and 73 (12.2%) would have false-negative results with 0 min and 120 min or 0 min and 210 min two-sample tests, respectively. The three-sample tests, 0 min, 120 min and 180 min or 0 min, 120 min and 210 min, have a false-negative rate of 5.9% and 2.1%, respectively. CONCLUSIONS: A three-sample H2BT is time-and cost-sparing without significant loss of sensitivity for the diagnosis both of lactose malabsorption and lactose intolerance. PMID:16609755

  20. Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption.

    PubMed

    Däbritz, Jan; Mühlbauer, Michael; Domagk, Dirk; Voos, Nicole; Henneböhl, Geraldine; Siemer, Maria L; Foell, Dirk

    2014-02-27

    Hydrogen breath tests are noninvasive procedures frequently applied in the diagnostic workup of functional gastrointestinal disorders. Here, we review hydrogen breath test results and the occurrence of lactose, fructose and sorbitol malabsorption in pediatric patients; and determine the significance of the findings and the outcome of patients with carbohydrate malabsorption. We included 206 children (88 male, 118 female, median age 10.7 years, range 3-18 years) with a total of 449 hydrogen breath tests (lactose, n = 161; fructose, n = 142; sorbitol, n = 146) into a retrospective analysis. Apart from test results, we documented symptoms, the therapeutic consequences of the test, the outcome and the overall satisfaction of the patients and families. In total, 204 (46%) of all breath tests were positive. Long-term follow-up data could be collected from 118 patients. Of 79 patients (67%) who were put on a diet reduced in lactose, fructose and/or sorbitol, the majority (92%, n = 73) reported the diet to be strict and only 13% (n = 10) had no response to diet. Most families (96%, n = 113) were satisfied by the test and the therapy. There were only 21 tests (5%) with a borderline result because the criteria for a positive result were only partially met. Hydrogen breath tests can be helpful in the evaluation of children with gastrointestinal symptoms including functional intestinal disorders. If applied for a variety of carbohydrates but only where indicated, around two-third of all children have positive results. The therapeutic consequences are successfully relieving symptoms in the vast majority of patients.

  1. Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption

    PubMed Central

    2014-01-01

    Background Hydrogen breath tests are noninvasive procedures frequently applied in the diagnostic workup of functional gastrointestinal disorders. Here, we review hydrogen breath test results and the occurrence of lactose, fructose and sorbitol malabsorption in pediatric patients; and determine the significance of the findings and the outcome of patients with carbohydrate malabsorption. Methods We included 206 children (88 male, 118 female, median age 10.7 years, range 3–18 years) with a total of 449 hydrogen breath tests (lactose, n = 161; fructose, n = 142; sorbitol, n = 146) into a retrospective analysis. Apart from test results, we documented symptoms, the therapeutic consequences of the test, the outcome and the overall satisfaction of the patients and families. Results In total, 204 (46%) of all breath tests were positive. Long-term follow-up data could be collected from 118 patients. Of 79 patients (67%) who were put on a diet reduced in lactose, fructose and/or sorbitol, the majority (92%, n = 73) reported the diet to be strict and only 13% (n = 10) had no response to diet. Most families (96%, n = 113) were satisfied by the test and the therapy. There were only 21 tests (5%) with a borderline result because the criteria for a positive result were only partially met. Conclusions Hydrogen breath tests can be helpful in the evaluation of children with gastrointestinal symptoms including functional intestinal disorders. If applied for a variety of carbohydrates but only where indicated, around two-third of all children have positive results. The therapeutic consequences are successfully relieving symptoms in the vast majority of patients. PMID:24575947

  2. High Precision 2.0 μm Photoacoustic Spectrometer for Determination of the ^{13}CO_{2}/^{12}CO_{2} Isotope Ratio

    NASA Astrophysics Data System (ADS)

    Reed, Zachary; Hodges, Joseph T.

    2017-06-01

    We have developed a portable photoacoustic spectrometer for high precision measurements of the ^{13}CO_{2}/^{12}CO_{2} isotope ratio and the absolute molar concentration of each isotope. The spectrometer extends on our previous work at 1.57 μm [1], and now employs two separate intensity modulated distributed feedback lasers and a fiber amplifier, operating in the 2.0 μm wavelength region. Each DFB is selected to probe individual spectrally isolated ro-vibrational transitions for ^{12}CO_{2} and ^{13}CO_{2}. The spectrometer is actively temperature controlled, mitigating variations in the two spectral line intensities and the temperature dependent system response. For measurements of ambient concentrations of carbon dioxide at nominally natural abundance in dry air, we demonstrate a measurement precision of 140 ppb for ^{12}CO_{2} with a 1 s averaging time and 10 ppb for ^{13}CO_{2} with a 60 s averaging time. Precision in δ13C of better than 0.1 permil is demonstrated. The analyzer response is calibrated in terms of certified gas mixtures and compared to characterization by cavity ringdown spectroscopy. We also investigate how water vapor affects the photoacoustic signals by promoting collisional relaxation for each isotope. [1] Z.D. Reed, B. Sperling, et al. App. Phys. B. 117, 645-657, 2014

  3. Non-invasive 13C-glucose breath test using residual gas analyzer-mass spectrometry: a novel tool for screening individuals with pre-diabetes and type 2 diabetes.

    PubMed

    Ghosh, Chiranjit; Maity, Abhijit; Banik, Gourab D; Som, Suman; Chakraborty, Arpita; Selvan, Chitra; Ghosh, Shibendu; Ghosh, Barnali; Chowdhury, Subhankar; Pradhan, Manik

    2014-09-01

    We report, for the first time, the clinical feasibility of a novel residual gas analyzer mass spectrometry (RGA-MS) method for accurate evaluation of the (13)C-glucose breath test ((13)C-GBT) in the diagnosis of pre-diabetes (PD) and type 2 diabetes mellitus (T2D). In T2D or PD, glucose uptake is impaired and results in blunted isotope enriched (13)CO2 production in exhaled breath samples. Using the Receiver operating characteristics (ROC) curve analysis, an optimal diagnostic cut-off point of the (13)CO2/(12)CO2 isotope ratios expressed as the delta-over-baseline (DOB) value, was determined to be δDOB(13)C‰ = 28.81‰ for screening individuals with non-diabetes controls (NDC) and pre-diabetes (PD), corresponding to a sensitivity of 100% and specificity of 94.4%. We also determined another optimal diagnostic cut-off point of δDOB(13)C‰ = 19.88‰ between individuals with PD and T2D, which exhibited 100% sensitivity and 95.5% specificity. Our RGA-MS methodology for the (13)C-GBT also manifested a typical diagnostic positive and negative predictive value of 96% and 100%, respectively. The diagnostic accuracy, precision and validity of the results were also confirmed by high-resolution optical cavity enhanced integrated cavity output spectroscopy (ICOS) measurements. The δDOB(13)C‰ values measured with RGA-MS method, correlated favourably (R(2) = 0.979) with those determined by the laser based ICOS method. Moreover, we observed that the effects of endogenous CO2 production related to basal metabolic rates in individuals were statistically insignificant (p = 0.37 and 0.73) on the diagnostic accuracy. Our findings suggest that the RGA-MS is a valid and sufficiently robust method for the (13)C-GBT which may serve as an alternative non-invasive point-of-care diagnostic tool for routine clinical practices as well as for large-scale diabetes screening purposes in real-time.

  4. Workplace Breathing Rates: Defining Anticipated Values and Ranges for Respirator Certification Testing

    DTIC Science & Technology

    2004-09-01

    performance tests most affected by airflow rate are filter gas-life capacity, particulate filter efficiency, and respirator breathing resistances...efficacy when tested under standard laboratory protocols. The relevance and adequacy of airflow rates used in respirator certification testing has been... airflow conditions. NIOSH-approved non-powered APR chemical cartridges and canisters (filter systems) are tested at a constant flow rate of 64 liters

  5. Magnesium hydrogen breath test using end expiratory sampling to assess achlorhydria in pernicious anaemia patients.

    PubMed Central

    Humbert, P; López de Soria, P; Fernández-Bañares, F; Juncá, J; Boix, J; Planas, R; Quer, J C; Domenech, E; Gassull, M A

    1994-01-01

    A modified magnesium hydrogen breath test, using end expiratory breath sampling, is described to investigate achlorhydria. The efficacy of this test in the diagnostic investigation of pernicious anaemia was compared with that of serum pepsinogen I. Twenty one patients with pernicious anaemia--that is, patients with achlorhydria--and 22 with healed duodenal ulcer and normal chlorhydria were studied. Magnesium hydrogen breath test, serum pepsinogen I, serum gastrin, and standard gastric acid secretory tests were performed in all subjects. The mean (SEM) hydrogen peak value was lower in patients with pernicious anaemia than in the duodenal ulcer group (21.7 (1.9) v 71.3 (5.2) ppm; p = 0.00005). The hydrogen peak value had a 95.2% sensitivity and a 100% specificity to detect pentagastrin resistant achlorhydria. Mean serum pepsinogen I concentrations were also significantly lower in patients with pernicious anaemia than in the duodenal ulcer group (10.7 (2.7) v 123.6 (11.8) micrograms/l p = 0.00005). Sensitivity and specificity to detect pernicious anaemia were both 100% for pepsinogen I. It is concluded that this modified magnesium hydrogen breath test is a simple, noninvasive, cost effective, and accurate method to assess achlorhydria and may be useful in the diagnostic investigation of patients with suspected pernicious anaemia. PMID:7959224

  6. Breath ketone testing: a new biomarker for diagnosis and therapeutic monitoring of diabetic ketosis.

    PubMed

    Qiao, Yue; Gao, Zhaohua; Liu, Yong; Cheng, Yan; Yu, Mengxiao; Zhao, Lingling; Duan, Yixiang; Liu, Yu

    2014-01-01

    Acetone, β -hydroxybutyric acid, and acetoacetic acid are three types of ketone body that may be found in the breath, blood, and urine. Detecting altered concentrations of ketones in the breath, blood, and urine is crucial for the diagnosis and treatment of diabetic ketosis. The aim of this study was to evaluate the advantages of different detection methods for ketones, and to establish whether detection of the concentration of ketones in the breath is an effective and practical technique. We measured the concentrations of acetone in the breath using gas chromatography-mass spectrometry and β -hydroxybutyrate in fingertip blood collected from 99 patients with diabetes assigned to groups 1 (-), 2 (±), 3 (+), 4 (++), or 5 (+++) according to urinary ketone concentrations. There were strong relationships between fasting blood glucose, age, and diabetic ketosis. Exhaled acetone concentration significantly correlated with concentrations of fasting blood glucose, ketones in the blood and urine, LDL-C, creatinine, and blood urea nitrogen. Breath testing for ketones has a high sensitivity and specificity and appears to be a noninvasive, convenient, and repeatable method for the diagnosis and therapeutic monitoring of diabetic ketosis.

  7. Breath Ketone Testing: A New Biomarker for Diagnosis and Therapeutic Monitoring of Diabetic Ketosis

    PubMed Central

    Qiao, Yue; Gao, Zhaohua; Liu, Yong; Cheng, Yan; Yu, Mengxiao; Zhao, Lingling

    2014-01-01

    Background. Acetone, β-hydroxybutyric acid, and acetoacetic acid are three types of ketone body that may be found in the breath, blood, and urine. Detecting altered concentrations of ketones in the breath, blood, and urine is crucial for the diagnosis and treatment of diabetic ketosis. The aim of this study was to evaluate the advantages of different detection methods for ketones, and to establish whether detection of the concentration of ketones in the breath is an effective and practical technique. Methods. We measured the concentrations of acetone in the breath using gas chromatography-mass spectrometry and β-hydroxybutyrate in fingertip blood collected from 99 patients with diabetes assigned to groups 1 (−), 2 (±), 3 (+), 4 (++), or 5 (+++) according to urinary ketone concentrations. Results. There were strong relationships between fasting blood glucose, age, and diabetic ketosis. Exhaled acetone concentration significantly correlated with concentrations of fasting blood glucose, ketones in the blood and urine, LDL-C, creatinine, and blood urea nitrogen. Conclusions. Breath testing for ketones has a high sensitivity and specificity and appears to be a noninvasive, convenient, and repeatable method for the diagnosis and therapeutic monitoring of diabetic ketosis. PMID:24900994

  8. Breath tests sustainability in hospital settings: cost analysis and reimbursement in the Italian National Health System.

    PubMed

    Volpe, M; Scaldaferri, F; Ojetti, V; Poscia, A

    2013-01-01

    The high demand of Breath Tests (BT) in many gastroenterological conditions in time of limited resources for health care systems, generates increased interest in cost analysis from the point of view of the delivery of services to better understand how use the money to generate value. This study aims to measure the cost of C13 Urea and other most utilized breath tests in order to describe key aspects of costs and reimbursements looking at the economic sustainability for the hospital. A hospital based cost-analysis of the main breath tests commonly delivery in an ambulatory setting is performed. Mean salary for professional nurses and gastroenterologists, drugs/preparation used and disposable materials, purchase and depreciation of the instrument and the testing time was used to estimate the cost, while reimbursements are based on the 2013 Italian National Health System ambulatory pricelist. Variables that could influence the model are considered in the sensitivity analyses. The mean cost for C13--Urea, Lactulose and Lactose BT are, respectively, Euros 30,59; 45,20 and 30,29. National reimbursement often doesn't cover the cost of the analysis, especially considering the scenario with lower number of exam. On the contrary, in high performance scenario all the reimbursement could cover the cost, except for the C13 Urea BT that is high influenced by the drugs cost. However, consideration about the difference between Italian Regional Health System ambulatory pricelist are done. Our analysis shows that while national reimbursement rates cover the costs of H2 breath testing, they do not cover sufficiently C13 BT, particularly urea breath test. The real economic strength of these non invasive tests should be considered in the overall organization of inpatient and outpatient clinic, accounting for complete diagnostic pathway for each gastrointestinal disease.

  9. Acidic colonic microclimate--possible reason for false negative hydrogen breath tests.

    PubMed

    Vogelsang, H; Ferenci, P; Frotz, S; Meryn, S; Gangl, A

    1988-01-01

    About 5% of normal subjects fail to produce increased hydrogen breath concentration after ingestion of the non-digestible carbohydrate lactulose (low hydrogen producers). The existence of low hydrogen producers limits the diagnostic use of hydrogen (H2) breath tests. We studied the effects of lactulose and of magnesium sulphate (MgSO4) pretreatment on stool-pH and on hydrogen exhalation after oral loading with lactulose or lactose in 17 hydrogen producers and 12 low hydrogen producers. In seven hydrogen producers acidification of stool pH by lactulose pretreatment (20 g tid) decreased hydrogen exhalation and three of seven (43%) became low hydrogen producers. In contrast, after pretreatment of eight low hydrogen producers with magnesium sulphate (5 g twice daily) all eight produced hydrogen after a lactulose load. Similarly four lactose intolerant low hydrogen producers had abnormal lactose hydrogen breath tests after MgSO4 pretreatment. MgSO4 pretreatment neither resulted in false positive lactose hydrogen breath tests in five lactose tolerant hydrogen producers, nor increased the hydrogen exhalation in five additional hydrogen producing controls after ingestion of lactulose. The results of these studies confirm that hydrogen production from lactulose decreases when the colonic pH is lower (lactulose pretreatment), and increases when colonic pH is higher (MgSO4 pretreatment). In low hydrogen producers the lacking increase of H2 exhalation after ingestion of non-digestible carbohydrates can be overcome by MgSO4 pretreatment, thus increasing the sensitivity of the test by avoiding false negative hydrogen breath tests in low hydrogen producers with disaccharide malabsorption or maldigestion. The underlying mechanism of this remarkable effect of MgSO4 pretreatment warrants further investigation.

  10. Additional Value of CH₄ Measurement in a Combined (13)C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis.

    PubMed

    Houben, Els; De Preter, Vicky; Billen, Jaak; Van Ranst, Marc; Verbeke, Kristin

    2015-09-07

    The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H₂) excretion after an oral dose of lactose. We use a combined (13)C/H₂ lactose breath test that measures breath (13)CO₂ as a measure of lactose digestion in addition to H₂ and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 (13)C/H₂ lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH₄ in addition to H₂ and (13)CO₂. Based on the (13)C/H₂ breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH₄ further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H₂-excretion were found to excrete CH₄. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH₄-concentrations has an added value to the (13)C/H₂ breath test to identify methanogenic subjects with lactose malabsorption or SIBO.

  11. Oral Adherence Monitoring Using a Breath Test to Supplement Highly Active Antiretroviral Therapy

    PubMed Central

    Morey, Timothy E.; Booth, Matthew; Wasdo, Scott; Wishin, Judith; Quinn, Brian; Gonzalez, Daniel; Derendorf, Hartmut; McGorray, Susan P.; Simoni, Jane; Melker, Richard J.; Dennis, Donn M.

    2012-01-01

    A breath-based adherence system to document ingestion of oral medications (e.g., HAART) was investigated. Specifically, the food additive 2-butanol, which can be easily packaged with a drug, is converted via alcohol dehydrogenase to the volatile metabolite 2-butanone that rapidly appears in breath, indicating adherence. In healthy adults using a portable sensor and GC-MS, the following experiments were performed: yield of 2-butanone in breath following ingestion of 2-butanol, adherence system accuracy, and potential interference of the adherence system by food or misplacement of 2-butanol on the tongue. During feasibility testing, every subject exhaled 2-butanone with 6.6±1.5 min to peak concentrations of 548±235 ppb following ingestion of 2-butanol (40 mg). ROC areas at 5 and 10 min were 0.95 (0.86–1.00) and 3 1.00 (1.00–1.00). Food did not interfere. Tongue application resulted in large concentrations of 2-butanol, but not 2-butanone. A breath test to provide definitive evidence of oral medication adherence appears technically feasible. PMID:23001413

  12. Starch absorption by healthy man evaluated by lactulose hydrogen breath test.

    PubMed

    Flourié, B; Florent, C; Etanchaud, F; Evard, D; Franchisseur, C; Rambaud, J C

    1988-01-01

    The amounts of hydrogen produced from starch and lactulose were compared to assess the accuracy of the hydrogen breath test with lactulose as standard to quantify starch malabsorption. The mean amounts of hydrogen produced from starch and lactulose were not different in fecal homogenates and in breath excretion after carbohydrate infusions into the cecum. Known amounts of starch infused into the cecum of 18 subjects were compared with amounts calculated from the total excess excretion of hydrogen in breath computed in relation to hydrogen production after the ingestion of 10 g lactulose; calculated amounts were 3.6 +/- 1.0, 9.9 +/- 1.3, and 22.0 +/- 3.4 g for the infusion of 5, 10, and 25 g of starch, respectively. The lactulose hydrogen breath test based on total excess hydrogen volume provides a valid measurement of the mean amount of starch metabolized in the colon in a group of subjects. However, large individual variations preclude its use in a given subject.

  13. Assessment of mitochondrial function in vivo with a breath test utilizing alpha-ketoisocaproic acid

    SciTech Connect

    Michaletz, P.A.; Cap, L.; Alpert, E.; Lauterburg, B.H. )

    1989-11-01

    A breath test to assess hepatic mitochondrial function in vivo was evaluated in rats. Following the i.p. administration of (1-{sup 14}C)-alpha-ketoisocaproic acid, {sup 14}CO{sub 2} exhalation reached a peak within 10 to 20 min and then declined exponentially, with a half-life of 14.3 min. Control animals exhaled 38.6% of the administered radioactivity within 1 hr. In functionally anhepatic animals, {sup 14}CO{sub 2} in breath amounted to 23% of that in control animals, indicating that alpha-ketoisocaproic acid decarboxylation reflects mainly hepatic mitochondrial function in vivo. Ethanol (3 gm per kg) significantly decreased alpha-ketoisocaproic acid decarboxylation (21.8% of the dose appearing in breath in 1 hr), probably due to the ethanol-induced shift in the NAD+:NADH ratio. In contrast, an uncoupler of mitochondrial respiration, sodium salicylate (375 mg per kg), increased the decarboxylation of alpha-ketoisocaproic acid (56.3% of the dose recovered as {sup 14}CO{sub 2} in 1 hr). Mitochondrial damage induced by 4-pentenoic acid decreased the decarboxylation of alpha-ketoisocaproic acid but did not affect the microsomal metabolism of antipyrine. The present data indicate that the alpha-ketoisocaproic acid breath test provides a noninvasive estimate of hepatic mitochondrial function in vivo which, when applied to man, might yield clinically useful information.

  14. Comparison of the analytical capabilities of the BAC Datamaster and Datamaster DMT forensic breath testing devices.

    PubMed

    Glinn, Michele; Adatsi, Felix; Curtis, Perry

    2011-11-01

    The State of Michigan uses the Datamaster as an evidential breath testing device. The newest version, the DMT, will replace current instruments in the field as they are retired from service. The Michigan State Police conducted comparison studies to test the analytical properties of the new instrument and to evaluate its response to conditions commonly cited in court defenses. The effects of mouth alcohol, objects in the mouth, and radiofrequency interference on paired samples from drinking subjects were assessed on the DMT. The effects of sample duration and chemical interferents were assessed on both instruments, using drinking subjects and wet-bath simulators, respectively. Our testing shows that Datamaster and DMT results are essentially identical; the DMT gave accurate readings as compared with measurements made using simulators containing standard ethanol solutions and that the DMT did not give falsely elevated breath alcohol results from any of the influences tested. © 2011 American Academy of Forensic Sciences.

  15. Alterations of the colonic flora and their effect on the hydrogen breath test.

    PubMed

    Gilat, T; Ben Hur, H; Gelman-Malachi, E; Terdiman, R; Peled, Y

    1978-07-01

    The hydrogen breath test was performed by ingestion of 20 g lactulose and analysis of end-expiratory air. Eighteen patients undergoing colonoscopy, 17 receiving antibiotics, 12 prepared for colon surgery, and 15 controls were examined. The test was repeated under control conditions in the treated patients. Eleven of 55 subjects failed to produce significant amounts of hydrogen under control conditions. This 20% proportion of non-hydrogen producers is much higher than that reported by other investigators. The hydrogen production was very markedly depressed after preparation for colonscopy and antibiotic therapy. The effect of neomycin and enemata as used in preparation for colon surgery was less marked. Hydrogen production by the colonic flora is thus subject to individual variations and may be affected by various therapeutic regimens. All these may cause false negative results when using the hydrogen breath test to evaluate carbohydrate absorption. The test should therefore not be performed for a considerable time after therapeutic manipulation of the colonic flora.

  16. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... gasoline vapor at room temperature (24-30 °C./75-85 °F.) for a continuous period of twice the rated time of the apparatus (except for apparatus for escape only where the test period shall be the rated time of...

  17. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... gasoline vapor at room temperature (24-30 °C./75-85 °F.) for a continuous period of twice the rated time of the apparatus (except for apparatus for escape only where the test period shall be the rated time of...

  18. Heart rate variability with deep breathing as a clinical test of cardiovagal function.

    PubMed

    Shields, Robert W

    2009-04-01

    Research into heart rate variability (HRV) and respiration over the past 150 years has led to the insight that HRV with deep breathing (HRVdb) is a highly sensitive measure of cardiovagal or parasympathetic cardiac function. This sensitivity makes HRVdb an important part of the battery of cardiovascular autonomic function tests used in clinical autonomic laboratories. HRVdb is a reliable and sensitive clinical test for early detection of cardiovagal dysfunction in a wide range of autonomic disorders.

  19. Protection Factor Testing of the 3M Breathe Easy (BE-10) Powered Air Purifying Respirator (PAPR)

    DTIC Science & Technology

    2003-05-01

    of the 3M Breathe Easy (BE-10) PAPR is described. A series of tests were performed to determine the corn -oil protection factors using human subjects...14. SUBJECT TERMS Corn oil Aerosol PAPR Respirator Cartridge Protection Factor (PF) Testing 15. NUMBER OF PAGES 24...scattering). The instrument can measure leakage into the mask by shining a laser over the cross-sectional area of the sample. If corn oil is present

  20. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2014-03-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: pulse and continuous labelling. We evaluate how these techniques perform to estimate the C transfer time, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides × nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom % 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom % 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and soil microbial biomass was extracted. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we applied a logistic function. Pulse labelling is best suited to assess the minimum C transfer time from the leaves to other compartments, while continuous labelling can be used to estimate the mean transfer time through a compartment, including short-term storage pools. The C partitioning between the plant-soil compartments obtained was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of labelling, when the

  1. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2013-10-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: the pulse and the continuous labelling. We evaluate how these techniques perform to estimate the C transfer velocity, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides x nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom% 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom% 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and the microbial biomass was extracted from the soil. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we suggest to use a logistic function. Pulse labelling is best suited to assess the maximum C transfer velocity from the leaves to other compartments. With continuous labelling, the mean transfer velocity through a compartment, including short-term storage pools, can be observed. The C partitioning between the plant-soil compartments was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of

  2. A new automatic chamber system for measuring soil surface CO2 and its isotopic (13CO2) effluxes in New Jersey Pinelands

    NASA Astrophysics Data System (ADS)

    Xu, M.

    2006-05-01

    A new automatic chamber system was developed to measure soil surface CO2 efflux with 16 pairs of chambers at hourly interval in an oak forest in New Jersey Pinelands. The trench method was applied to separate root respiration from the total soil respiration. I found that soil temperature and moisture alternatively control root and soil heterotrophic respiration in different seasons based on the data collected in about 3 years. The isotopic flux of soil 13CO2 was also measured at hourly interval using the chamber system with a new laser-based stable carbon isotope analyzer.

  3. Biogenic volatile organic compounds (BVOCs) emission of Scots pine under drought stress - a 13CO2 labeling study to determine de novo and pool emissions under different treatments

    NASA Astrophysics Data System (ADS)

    Lüpke, M.

    2015-12-01

    Plants emit biogenic volatile organic compounds (BVOCs) to e.g. communicate and to defend herbivores. Yet BVOCs also impact atmospheric chemistry processes, and lead to e.g. the built up of secondary organic aerosols. Abiotic stresses, such as drought, however highly influence plant physiology and subsequently BVOCs emission rates. In this study, we investigated the effect of drought stress on BVOCs emission rates of Scots pine trees, a de novo and pool emitter, under controlled climate chamber conditions within a dynamic enclosure system consisting of four plant chambers. Isotopic labeling with 13CO2 was used to detect which ratio of emissions of BVOCs derives from actual synthesis and from storage organs under different treatments. Additionally, the synthesis rate of the BVOCs synthesis can be determined. The experiment consisted of two campaigns (July 2015 and August 2015) of two control and two treated trees respectively in four controlled dynamic chambers simultaneously. Each campaign lasted for around 21 days and can be split into five phases: adaptation, control, dry-out, drought- and re-watering phase. The actual drought phase lasted around five days. During the campaigns two samples of BVOCs emissions were sampled per day and night on thermal desorption tubes and analyzed by a gas chromatograph coupled with a mass spectrometer and a flame ionization detector. Additionally, gas exchange of water and CO2, soil moisture, as well as leaf and chamber temperature was monitored continuously. 13CO2 labeling was performed simultaneously in all chambers during the phases control, drought and re-watering for five hours respectively. During the 13CO2 labeling four BVOCs emission samples per chamber were taken to identify the labeling rate on emitted BVOCs. First results show a decrease of BVOCs emissions during the drought phase and a recovery of emission after re-watering, as well as different strength of reduction of single compounds. The degree of labeling with 13

  4. Fatty acid breath test values in the malabsorption range in cancer patients

    SciTech Connect

    Delaney, W.E.; Stuart, R.K.; Ettinger, D.S.

    1982-01-01

    Fatty acid absorption breath tests (FABT) were found to be abnormal in most subjects in a group of cancer patients selected to exclude common causes of abnormal lipid absorption, including chemotherapy and radiation therapy. The breath tests were abnormal in both quality (delayed peak in 9 of 10 patients) and quantity (reduced maximum peak in 5 of 10 patients) of fatty acid absorption. Retrospective separation of patients into 2 groups (normal or low maximum peak height FABT), either at a common time after the start of the test or at each individual's maximum peak height FABT regardless of time, was significant at 0.005 and 0.001, respectively. The low maximum peak heights were in the range of the malabsorption syndrome. Further studies of pancreatic function and fat malabsorption are warranted before the abnormal results can be ascribed to altered intermediary metabolism or peripheral utilization of lipids.

  5. Two-stage triolein breath test differentiates pancreatic insufficiency from other causes of malabsorption

    SciTech Connect

    Goff, J.S.

    1982-07-01

    In 24 patients with malabsorption, (/sup 14/C)triolein breath tests were conducted before and together with the administration of pancreatic enzymes (Pancrease, Johnson and Johnson, Skillman, N.J.). Eleven patients with pancreatic insufficiency had a significant rise in peak percent dose per hour /sup 14/CO/sub 2/ excretion after Pancrease, whereas 13 patients with other causes of malabsorption had no increase in /sup 14/CO/sub 2/ excretion (2.61 +/- 0.96 vs. 0.15 +/- 0.45, p less than 0.001). The two-stage (/sup 14/C)triolein breath test appears to be an accurate and simple noninvasive test of fat malabsorption that differentiates steatorrhea secondary to pancreatic insufficiency from other causes of steatorrhea.

  6. Hydrogen breath test assessment of orocecal transit time: comparison with barium meal study.

    PubMed

    Hirakawa, M; Iida, M; Kohrogi, N; Fujishima, M

    1988-12-01

    Orocecal transit time was measured simultaneously by the hydrogen breath test and a barium meal study in 12 hospitalized patients, the objective being to determine whether the former test accurately represents the orocecal transit time, and to establish an adequate criterion for the transit time, based on the former test. Two definitions of orocecal transit time by the hydrogen breath test were evaluated: the time from lactulose ingestion to a sustained increase of over 5 ppm above fasting levels in the end-expiratory hydrogen concentration (definition A) and the interval to that of over 10 ppm (definition B). The orocecal transit time measured by the radiologic method was 63 +/- 9 min (mean +/- SEM), whereas that using definition A of the hydrogen breath test was 74 +/- 9 min, and that using definition B was 87 +/- 10 min. Transit times determined by both definitions closely correlated with that obtained by the radiologic method (A, r = 0.86, p less than 0.01; B, r = 0.81, p less than 0.01). Therefore, elevation of end-expiratory hydrogen concentrations seemed to coincide with cecal appearance of the head of the lactulose load. When the mean transit times were compared with findings in case of the radiologic method, definition A rather than B appeared to be more appropriate to determine orocecal transit time.

  7. Role of Breathing Conditions During Exercise Testing on Training Prescription in Chronic Obstructive Pulmonary Disease.

    PubMed

    Neunhäuserer, Daniel; Steidle-Kloc, Eva; Bergamin, Marco; Weiss, Gertraud; Ermolao, Andrea; Lamprecht, Bernd; Studnicka, Michael; Niebauer, Josef

    2017-06-21

    This study investigated whether different breathing conditions during exercise testing will influence measures of exercise capacity commonly used for training prescription in chronic obstructive pulmonary disease. Twenty-seven patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 sec = 45.6 [9.4]%) performed three maximal exercise tests within 8 days, but at least 48 hrs apart. Subjects were thereby breathing either room air through a tightly fitting face mask like during any cardiopulmonary exercise test (MASK), room air without mask (No-MASK), or 10 l/min of oxygen via nasal cannula (No-MASK + O2). Cycling protocols were identical for all tests (start = 20 watts, increment = 10 males/5 females watts/min). Maximal work rate (90.4 [33.8], 100.3 [34.8], 107.4 [35.9] watts, P < 0.001) and blood lactate at exhaustion (4.3 [1.5], 5.2 [1.6], 5.0 [1.4] mmol/l, P < 0.001) were lowest for MASK when compared with No-MASK and No-MASK + O2, respectively, whereas maximal heart rate did not differ significantly. Submaximal exertion (Borg rating of perceived exertion = 12-14) was perceived at lower intensity (P = 0.008), but higher heart rate (P = 0.005) when MASK was compared with No-MASK and No-MASK + O2. Different breathing conditions during exercise testing resulted in an 18.8% difference in maximal work rate, likely causing underdosing or overdosing of exercise in chronic obstructive pulmonary disease. Face masks reduced whereas supplemental oxygen increased patients' exercise capacity. For accurate prescription of exercise in chronic obstructive pulmonary disease, breathing conditions during testing should closely match training conditions.

  8. [Lactose deficient intestinal absorption (LDIA) in a population of healthy Mexican children studied with the hydrogen ion test in air breathing].

    PubMed

    Cervantes Bustamante, R; Ramirez Mayans, J A; Orozco Martinez, S; Figueroa Solano, J; Rizo Garnica, L; Oyervides García, C I; Mata Rivera, N; Sosa de Martinez, C; Muñoz Medina, L

    1996-01-01

    We studied 100 healthy children looking for lactose malabsortion. We performed in all of them the lactose breath test. We found a 10% with lactose malabsortion. There was no correlation between lactose breath test and fecal reducing substances.

  9. Correlation between gastric transit time measured by video capsule endoscopy and gastric emptying determined by the continuous real-time 13C breath test (BreathID system).

    PubMed

    Nonaka, Takashi; Inamori, Masahiko; Endo, Hiroki; Matsuura, Mizue; Uchiyama, Shiori; Yamada, Eiji; Sekino, Yusuke; Sakai, Eiji; Higurashi, Takuma; Ohkubo, Hidenori; Akimoto, Keiko; Iida, Hiroshi; Takahashi, Hirokazu; Koide, Tomoko; Shibata, Wataru; Ida, Tomonori; Kusakabe, Akihiko; Gotoh, Eiji; Nakajima, Atsushi; Maeda, Shin

    2014-10-01

    The aim of this study was to determine the possible existence of a correlation between the gastric transit time (GTT) measured by video capsule endoscopy (VCE) and the parameters of gastric emptying determined using 13C breath test (BreathID system). Eight healthy male volunteers participated in this randomized, two-way crossover study. The subjects were randomly assigned to undergo VCE using the PillCam SB capsule endoscopy system or the 13C breath test for 4 hours after a test meal (400 kcal per 400 mL) containing 100 mg of 13C acetic acid administered after overnight fasting. The VCE images were analyzed and the GTT was determined using the proprietary RAPID software. The parameters, namely T lag, T 1/2 and GEC were calculated using the Oridion Research Software (β version). The GTT measured by VCE and the parameters of gastric emptying were compared statistically. No significant correlation was observed between the GTT and T lag (p = 0.5263), T 1/2 (p = 0.4100) or GEC (p = 0.2410), as determined by calculation of the Spearman’s rank correlation coefficient. GTT measured by VCE cannot serve as asubstitute for the gastric emptying time measured bythe 13C breath test.

  10. A study to investigate the ability of subjects with chronic lung diseases to provide evidential breath samples using the Lion Intoxilyzer 6000 UK breath alcohol testing device.

    PubMed

    Honeybourne, D; Moore, A J; Butterfield, A K; Azzan, L

    2000-07-01

    The Lion Intoximeter 3000 has been used for evidential breath testing in the U.K. for some years. Some individuals with lung diseases have difficulty in providing evidential breath samples using the device. This study describes an investigation that we have carried out on a newer instrument--the Lion Intoxilyzer 6000UK--which is now in use in the U.K. The study was designed to investigate the ability of subjects with a variety of lung diseases to provide evidential breath samples using this device. The 40 adult subjects investigated comprized 10 normal controls, 10 with asthma, 10 with chronic obstructive pulmonary disease (COPD) and 10 with restrictive lung disease. After baseline spirometry, subjects were given alcohol to drink, the quantity based upon body weight. After a gap of at least 20 min, subjects were asked to provide evidential breath samples in accordance with.the test procedure built into the Lion Intoxilyzer 6000UK. The results showed that two asthmatic subjects, four with COPD and three with restrictive lung disease failed to provide evidential breath samples even after four attempts. Despite the device requiring a minimum sample volume of 1.2 l, eight of the nine subjects who failed had a forced vital capacity (FVC) of more than 1.5 l. Seven of these nine subjects had a forced expiratory volume in 1 sec (FEV1) of less than 1.0 l. In conclusion, this study has shown that some subjects with lung diseases may have difficulty in providing evidential breath samples using the Lion Intoxilyzer 6000 UK.

  11. When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans

    PubMed Central

    Nierat, Marie-Cécile; Demiri, Suela; Dupuis-Lozeron, Elise; Allali, Gilles; Morélot-Panzini, Capucine; Similowski, Thomas; Adler, Dan

    2016-01-01

    Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the “irruption of breathing into consciousness” interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine's curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by “timed up-and-go” test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here. PMID:26978782

  12. When Breathing Interferes with Cognition: Experimental Inspiratory Loading Alters Timed Up-and-Go Test in Normal Humans.

    PubMed

    Nierat, Marie-Cécile; Demiri, Suela; Dupuis-Lozeron, Elise; Allali, Gilles; Morélot-Panzini, Capucine; Similowski, Thomas; Adler, Dan

    2016-01-01

    Human breathing stems from automatic brainstem neural processes. It can also be operated by cortico-subcortical networks, especially when breathing becomes uncomfortable because of external or internal inspiratory loads. How the "irruption of breathing into consciousness" interacts with cognition remains unclear, but a case report in a patient with defective automatic breathing (Ondine's curse syndrome) has shown that there was a cognitive cost of breathing when the respiratory cortical networks were engaged. In a pilot study of putative breathing-cognition interactions, the present study relied on a randomized design to test the hypothesis that experimentally loaded breathing in 28 young healthy subjects would have a negative impact on cognition as tested by "timed up-and-go" test (TUG) and its imagery version (iTUG). Progressive inspiratory threshold loading resulted in slower TUG and iTUG performance. Participants consistently imagined themselves faster than they actually were. However, progressive inspiratory loading slowed iTUG more than TUG, a finding that is unexpected with regard to the known effects of dual tasking on TUG and iTUG (slower TUG but stable iTUG). Insofar as the cortical networks engaged in response to inspiratory loading are also activated during complex locomotor tasks requiring cognitive inputs, we infer that competition for cortical resources may account for the breathing-cognition interference that is evidenced here.

  13. C13 urea breath test accuracy analysis against former C14 urea breath test technique: is there still a need for an indeterminate result category?

    PubMed

    Charest, Mathieu; Belair, Marc-Andre

    2017-03-09

    Helicobacter pylori (H. Pylori) infection is the leading cause of peptic ulcer disease. Purpose: To assess the difference in distribution of negative versus positive breath test results between the former C14 urea breath test (UBT) and the newer C13 UBT. Second, to determine if the use of an indeterminate category is still meaningful and what type of results should trigger a repeat testing. Methods: Retrospective survey was performed of all consecutive patients referred to our service for a UBT. We analysed 562 patients with C14 UBT and 454 patients with C13 UBT. Results: C13 negative results are distributed farther away from the cut-off value and grouped more tightly around the mean negative value, as compare to the more widely distributed C14 negative results. Distribution analysis of the negative results of the C13 UBT compare to the negative results of the C14 UBT reveals a statistically significant difference. Within the C13 UBT group, only 1 patient could have been classify as having an indeterminate result using the same indeterminate zone previously used with C14 UBT. This is significantly less frequent than what was previously found with C14 UBT. Discussion: Borderline negative result do occurs with C13 UBT, although less frequently then with the C14 UBT, and we will carefully monitored results falling between 3.0 and 3.5 %delta. C13 UBTis a safe and simple test for the patient, provides a clearer positive or negative test results for the clinician in the majority of cases.

  14. Update on diagnostic value of breath test in gastrointestinal and liver diseases

    PubMed Central

    Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

    2016-01-01

    In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

  15. Effects of waterlogging on carbon assimilate partitioning in the Zoigê alpine wetlands revealed by 13CO2 pulse labeling.

    PubMed

    Gao, Jun-Qin; Gao, Ju-Juan; Zhang, Xue-Wen; Xu, Xing-Liang; Deng, Zhao-Heng; Yu, Fei-Hai

    2015-03-23

    Waterlogging has been suggested to affect carbon (C) turnover in wetlands, but how it affects C allocation and stocks remains unclear in alpine wetlands. Using in situ (13)CO2 pulse labelling, we investigated C allocation in both waterlogged and non-waterlogged sites in the Zoigê wetlands on the Tibetan Plateau in August 2011. More than 50% of total (13)C fixed by photosynthesis was lost via shoot respiration. Shoots recovered about 19% of total (13)C fixed by photosynthesis at both sites. Only about 26% of total fixed (13)C was translocated into the belowground pools. Soil organic C pool accounted for 19% and roots recovered about 5-7% of total fixed (13)C at both sites. Waterlogging significantly reduced soil respiration and very little (13)C was lost via soil respiration in the alpine wetlands compared to that in grasslands. We conclude that waterlogging did not significantly alter C allocations among the C pools except the (13)CO2 efflux derived from soil respiration and that shoots made similar contributions to C sequestration as the belowground parts in the Zoigê alpine wetlands. Therefore, changes in waterlogging due to climate change will not affect C assimilate partitioning but soil C efflux.

  16. A Modified Carbon Monoxide Breath Test for Measuring Erythrocyte Lifespan in Small Animals

    PubMed Central

    Ma, Yong-Jian; Zhang, Hou-De; Ji, Yong-Qiang; Zhu, Guo-Liang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Du, Ji-Hui; Li, Rong; Wang, Lei

    2016-01-01

    This study was to develop a CO breath test for RBC lifespan estimation of small animals. The ribavirin induced hemolysis rabbit models were placed individually in a closed rebreath cage and air samples were collected for measurement of CO concentration. RBC lifespan was calculated from accumulated CO, blood volume, and hemoglobin concentration data. RBC lifespan was determined in the same animals with the standard biotin-labeling method. RBC lifespan data obtained by the CO breath test method for control (CON, 49.0 ± 5.9 d) rabbits, rabbits given 10 mg/kg·d−1 of ribavirin (RIB10, 31.0 ± 4.0 d), and rabbits given 20 mg/kg·d−1 of ribavirin (RIB20, 25.0 ± 2.9 d) were statistically similar (all p > 0.05) to and linearly correlated (r = 0.96, p < 0.01) with the RBC lifespan data obtained for the same rabbits by the standard biotin-labeling method (CON, 51.0 ± 2.7 d; RIB10, 33.0 ± 1.3 d; and RIB20, 27.0 ± 0.8 d). The CO breath test method takes less than 3 h to complete, whereas the standard method requires at least several weeks. In conclusion, the CO breath test method provides a simple and rapid means of estimating RBC lifespan and is feasible for use with small animal models. PMID:27294128

  17. Investigating the impact of light and water status on the exchange of COS, 13CO2, CO18O and H218O from bryophytes

    NASA Astrophysics Data System (ADS)

    Gimeno, Teresa; Royles, Jessica; Ogee, Jerome; Jones, Samuel; Burlett, Regis; West, Jason; Sauze, Joana; Wohl, Steven; Genty, Bernard; Griffiths, Howard; Wingate, Lisa

    2016-04-01

    Terrestrial surfaces are often covered by photoautotrophic communities that play a significant role in the biological fixation of C and N at the global scale. Bryophytes (mosses, liverworts and hornworts) are key members in these communities and are especially adapted to thrive in hostile environments, by growing slowly and surviving repeated dehydration events. Consequently, bryophyte communities can be extremely long-lived (>1500yrs) and can serve as valuable records of historic climate change. In particular the carbon and oxygen isotope compositions of mosses can be used as powerful proxies describing how growing season changes in atmospheric CO2 and rainfall have changed in the distant past over the land surface. Interpreting the climate signals of bryophyte biomass requires a robust understanding of how changes in photosynthetic activity and moisture status regulate the growth and isotopic composition of bryophyte biomass. Thus theoretical models predicting how changes in isotopic enrichment and CO2 discrimination respond to dehydration and rehydration are used to tease apart climatic and isotopic source signals. Testing these models with high resolution datasets obtained from new generation laser spectrometers can provide more information on how these plants that lack stomata cope with water loss. In addition novel tracers such as carbonyl sulfide (COS) can also be measured at high resolution and precision (<5ppt) and used to constrain understanding of diffusional and enzymatic limitations during dehydration and rehydration events in the light and the dark. Here, we will present for the first time simultaneous high-resolution chamber measurements of COS, 13CO2, CO18O and H218O fluxes by a bryophyte species (Marchantia sp.) in the light and during the dark, through complete desiccation cycles. Our measurements consistently reveal a strong enrichment dynamic in the oxygen isotope composition of transpired water over the dessication cycle that caused an increase

  18. Carbon-14 urea breath test: does it work in patients with partial gastric resection?

    PubMed

    Dede, Fuat; Civen, Hüseyin; Dane, Faysal; Aliustaoglu, Mehmet; Turhal, Serdar; Turoglu, Halil Turgut; Inanir, Sabahat

    2015-11-01

    The diagnostic value of Carbon-14 urea breath test (C-14 UBT) in the detection of Helicobacter pylori (H. pylori) infection in non-operated patients has been proved. However, the efficacy of C-14 UBT in patients with partial gastric resection (PGR) has not been evaluated yet. Herein, the results of the C-14 UBT and H. pylori stool antigen test (HpSAT) in this patient group were compared with the endoscopic findings. Multi-breath samples C-14 UBT and HpSAT were performed in all patients on the same day. Histology was used as a gold standard for testing C-14 UBT and HpSAT diagnostic efficacies. 30 patients (mean age: 54.6 ± 11 year) with PGR were included. The sensitivity and specificity of standard C-14 UBT were 29 and 100 %, respectively. When breath samples were collected at 20th min, and >35 CPM was selected as radioactivity threshold, the sensitivity raised to 86 % without any loss of specificity. The specificity and sensitivity of the HpSAT were 71 and 96 %, respectively. The sensitivity of the standard C-14 UBT was very poor for patients with PGR, and results of HpSAT were superior in this population. Certain modifications are needed if C-14 UBT is to be used in PGR patients.

  19. An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Surampudi, Anand B.

    2008-10-01

    We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring.

  20. On the importance of developing a new generation of breath tests for Helicobacter pylori detection.

    PubMed

    Kushch, Ievgeniia; Korenev, Nikolai; Kamarchuk, Lyudmila; Pospelov, Alexander; Kravchenko, Andrey; Bajenov, Leonid; Kabulov, Mels; Amann, Anton; Kamarchuk, Gennadii

    2015-12-15

    State-of-the-art methods for non-invasive detection of the Helicobacter pylori (H. pylori) infection have been considered. A reported global tendency towards a non-decreasing prevalence of H. pylori worldwide could be co-influenced by the functional limitations of urea breath tests (UBTs), currently preferred for the non-invasive recognition of H. pylori in a clinical setting. Namely, the UBTs can demonstrate false-positive or false-negative results. Within this context, limitations of conventional clinically exploited H. pylori tests have been discussed to justify the existing need for the development of a new generation of breath tests for the detection of H. pylori and the differentiation of pathogenic and non-pathogenic strains of the bacterium. This paper presents the results of a pilot clinical study aimed at evaluating the development and diagnostic potential of a new method based on the detection of the non-urease products of H. pylori vital activity in exhaled gas. The characteristics of breath of adolescents with H. pylori-positive and H. pylori-negative functional dyspepsia, together with a consideration of the cytotoxin-associated gene A (CagA) status of H. pylori-positive subjects, have been determined for the first time using innovative point-contact nanosensor devices based on salts of the organic conductor tetracyanoquinodimethane (TCNQ). The clinical and diagnostic relevance of the response curves of the point-contact sensors was assessed. It was found that the recovery time of the point-contact sensors has a diagnostic value for differentiation of the H. pylori-associated peptic ulcer disease. The diagnostically significant elongation of the recovery time was even more pronounced in patients infected with CagA-positive H. pylori strains compared to the CagA-negative patients. Taking into account the operation of the point-contact sensors in the real-time mode, the obtained results are essential prerequisites for the development of a fast and

  1. Comprehensive Assessment of Gastric Emptying with a Stable Isotope Breath Test

    PubMed Central

    Bharucha, Adil E.; Camilleri, Michael; Veil, Erica; Burton, Duane; Zinsmeister, Alan R.

    2012-01-01

    Background The [13C]-Spirulina platensis gastric emptying breath test (GEBT) with 5 samples is accurate relative to scintigraphy. This study was primarily designed to further validate this GEBT using a slightly different process for incorporating [13C] in Spirulina and to evaluate the utility of additional samples for assessing early gastric emptying. Methods After a 223 kcal test meal labeled with 99mTc and [13C]-Spirulina platensis, scintigraphic images and 5 breath samples (45, 90, 120, 180, and 240 minutes, GEBT5) were collected in 14 controls (Part A). In Part B, 9 breath samples were collected at 15, 30, 45, 60, 90, 120, 150, 180, and 240 minutes (GEBT9) in 30 subjects (15 controls, 15 dyspepsia). Using correlation between [13C] breath excretion and scintigraphic emptying, lag time (t10, time for 10% emptying), emptying at 30 min (GE30), and half time (t50) were estimated for GEBT5 (Parts A and B) and GEBT9 (Part B). Key Results t50 values for scintigraphy, GEBT5, and GEBT9 were highly concordant. t10 by GEBT9 (90% CI, 6–15 minutes) was more strongly correlated (CCC 0.80 [95% CI, 0.63–0.90]) with scintigraphy (90% CI, 5–12 minutes), than GEBT5 (10–19 minutes, CCC 0.73 [95% CI, 0.54–0.85]). The correlation between estimated values (GEBT9) and linearly interpolated values (GEBT5) was closer at 60 (CCC 0.95 [95% CI, 0.91–0.97]) than 30 minutes (CCC 0.81 [95% CI, 0.71–0.89]). Conclusions & Inferences The [13C]-Spirulina platensis GEBT can accurately measure GE. While 5 and 9 samples are equally accurate for measuring t50, GEBT9 provides a more comprehensive assessment of early GE (t10 and GE30). PMID:23216872

  2. Riverine GHG emissions: one year of CO2, 13CO2 and CH4 flux measurements on Vistula river in Krakow, southern Poland

    NASA Astrophysics Data System (ADS)

    Jasek, Alina; Wachniew, Przemyslaw; Zimnoch, Miroslaw

    2013-04-01

    Terrestrial surface waters are generally considered to be sources of carbon dioxide and methane, because respiration of organic matter via aerobic and anaerobic pathways causes supersaturation of surface waters with respect to CO2 and CH4, respectively. In rivers, these processes are influenced by such anthropogenic factors as changes of land-use, wastewater and alteration of river channels. The research object is Vistula, the largest Polish river. It has the length of 1047 km and annual runoff of 6.2x1010m3. The urban section of Vistula in Krakow receives large amounts of organic matter from highly urbanized catchment and point discharges of urban waste waters within the city limits. The river was sampled regularly at three points: the entrance to the city, the center and the point where Vistula leaves the agglomeration. A floating chamber coupled with Picarro G2101-i analyzer was applied to quantify CO2, 13CO2 and CH4 fluxes leaving the surface of the river. A floating chamber was equipped with sensors to measure air pressure, temperature and humidity inside the chamber and the temperature of water. The chamber was equipped with a set of floats and an anchor. The measurements started in October 2011, and were repeated with approximately monthly frequency. Physicochemical properties of water (temperature, conductivity, pH, CO2 partial pressure over the water surface and alkalinity) were also measured during each measurement campaign. In addition, at each site short-term variability of the measured fluxes was also investigated. Additionally, short-term variability of the measured fluxes of CO2, 13CO2 and CH4 were performed in all three sites. The results indicate that fluxes of CO2 released from the river are comparable with the soil emissions of this gas measured in Krakow area. The δ13CO2 signature of riverine CO2 flux allowed to identify decomposition of C3 organic matter as the major source of this gas. No distinct seasonal variability of the CO2 emission and

  3. Spontaneous breathing test in the prediction of extubation failure in the pediatric population.

    PubMed

    Nascimento, Milena Siciliano; Rebello, Celso Moura; Vale, Luciana Assis Pires Andrade; Santos, Érica; Prado, Cristiane do

    2017-01-01

    To assess whether the spontaneous breathing test can predict the extubation failure in pediatric population. A prospective and observational study that evaluated data of inpatients at the Pediatric Intensive Care Unit between May 2011 and August 2013, receiving mechanical ventilation for at least 24 hours followed by extubation. The patients were classified in two groups: Test Group, with patients extubated after spontaneous breathing test, and Control Group, with patients extubated without spontaneous breathing test. A total of 95 children were enrolled in the study, 71 in the Test Group and 24 in the Control Group. A direct comparison was made between the two groups regarding sex, age, mechanical ventilation time, indication to start mechanical ventilation and respiratory parameters before extubation in the Control Group, and before the spontaneous breathing test in the Test Group. There was no difference between the parameters evaluated. According to the analysis of probability of extubation failure between the two groups, the likelihood of extubation failure in the Control Group was 1,412 higher than in the Test Group, nevertheless, this range did not reach significance (p=0.706). This model was considered well-adjusted according to the Hosmer-Lemeshow test (p=0.758). The spontaneous breathing test was not able to predict the extubation failure in pediatric population. Avaliar se o teste de respiração espontânea pode ser utilizado para predizer falha da extubação na população pediátrica. Estudo prospectivo, observacional, no qual foram avaliados todos os pacientes internados no Centro de Terapia Intensiva Pediátrica, no período de maio de 2011 a agosto de 2013, que utilizaram ventilação mecânica por mais de 24 horas e que foram extubados. Os pacientes foram classificados em dois grupos: Grupo Teste, que incluiu os pacientes extubados depois do teste de respiração espontânea; e Grupo Controle, pacientes foram sem teste de respiração espont

  4. The cholyl glycine-1-14C breath test in various gastrointestinal disorders.

    PubMed

    Peled, Y; Levy-Gigi, C; Ayalon, D; Gilat, T

    1979-01-01

    The cholyl glycine-1-14C breath test was evaluated in a variety of gastrointestinal disorders. 138 tests were performed in 106 patients. Methods of data expression were evaluated and the cumulative 8-hour value was used. In 27 control patients the upper limit of the normal was found to be 78. A good correlation was found between the peak values and the cumulative 8-hour values (r = 0.95, p less than 0.01). The reproducibility of the test was good (r = 0.985, p less than 0.05). Abnormal results were found in 12 out of 13 cases with resection of the ileum and 11 out of 14 cases with Crohn's disease of the distal small bowel. The test was normal in cases with diseases of the proximal small bowel (celiac, Whipple's and Chron's diseases). The test was also normal in patients with colitis. It was abnormal in some of the cases after cholecystectomy and in most cases with carcinoma of the pancreas. The breath test was useful in monitoring the results of treatment in bacterial overgrowth of the small bowel. False negative results were observed after antibiotic treatment. The method seems to be more sensitive than the Schilling test in diagnosing disease of the distal small bowel.

  5. Helicobacter pylori infection is associated with high methane production during lactulose breath test.

    PubMed

    Del Zompo, F; Ojetti, V; Feliciani, D; Mangiola, F; Petruzziello, C; Tesori, V; Gaetani, E; Gasbarrini, A; Franceschi, F

    2016-08-01

    Despite a growing interest toward the interplay between H. pylori and gastric microbiota, few data are available about this correlation. The aim of this study was to explore the relationship between H. pylori infection and gas production during lactulose breath test. Data of patients undergoing both 13C-urea breath test (UBT) and lactulose breath test (LBT) under standard conditions in our GI unit were retrospectively analyzed. GI symptoms, such as dyspepsia, bloating, abdominal pain/discomfort, and epigastric pain on an eleven-point scale were also analyzed and correlate with the results of those tests. H2 and CH4 were calculated using the trapezoidal rule; a considerable CH4 production was defined by AUCCH4 ≥1200 ppm*4h. Statistical analyses were performed with Fisher's exact test and independent samples Mann-Whitney test. Data of 136 patients during a period of time of 3 months were analyzed. 36 patients (26.5%) showed a positive UBT. We do not find any difference as regards age, sex, symptom complaints, and small intestinal bacterial overgrowth between HP negative and positive patients. A greater methane production was observed in infected rather than non-infected patients (47.2% vs. 26% respectively, p=0.02). Furthermore, 25% infected and 10% non-infected produced greater amounts of CH4 compared to H2, resulting in a AUCCH4/AUCH2 ratio >1 (p=0.046). This study shows for the first time, a significant association between H. pylori infection and methane production, suggesting that H. pylori might influence gut microbiota composition. Further studies are needed to clarify mechanisms underlying this phenomenon.

  6. Carbohydrate malabsorption in infants with diarrhea studied with the breath hydrogen test.

    PubMed

    Lifschitz, C H; Irving, C S; Gopalakrishna, G S; Evans, K; Nichols, B L

    1983-03-01

    Fermentation of malabsorbed carbohydrate (CHO) reaching the colon was studied by measuring peak breath hydrogen (H2) production between feedings in 28 H2-producing hospitalized infants with diarrhea. Patients who required fewer than six days of hospitalization had lower breath H2 values when tested soon after admission than those who required longer stays. Patients hospitalized for more than five days had lower H2 amounts at discharge than on admission. Peak breath H2 values decreased when glucose was substituted for glucose polymers in formulas, or when the formula was fed by continuous drip via a nasogastric tube instead of by orally administered bolus. Glucose-positive and acidic stools were encountered occasionally and were associated with decreased H2 levels. The responses of H2 levels, stool pH, and glucose excretion after changes in patient management or intestinal metabolism of CHO reflect alterations in the balance between proximal intestinal absorption and distal colonic fermentation. Malabsorbed CHO that reaches a competent colon is utilized via microbial conversion, as indicated by high H2 levels, in the absence of glucose-positive and acidic stools. The presence of glucose in the feces or acidic stools indicates an inability of the colon to completely metabolize and absorb CHO or its products of fermentation.

  7. Comparison of breath testing with fructose and high fructose corn syrups in health and IBS

    PubMed Central

    Skoog, S. M.; Bharucha, A. E.; Zinsmeister, A. R.

    2008-01-01

    Although incomplete fructose absorption has been implicated to cause gastrointestinal symptoms, foods containing high fructose corn syrup (HFCS) contain glucose. Glucose increases fructose absorption in healthy subjects. Our hypothesis was that fructose intolerance is less prevalent after HFCS consumption compared to fructose alone in healthy subjects and irritable bowel syndrome (IBS). Breath hydrogen levels and gastrointestinal symptoms were assessed after 40 g of fructose (12% solution) prepared either in water or as HFCS, administered in double-blind randomized order on 2 days in 20 healthy subjects and 30 patients with IBS. Gastrointestinal symptoms were recorded on 100-mm Visual Analogue Scales. Breath hydrogen excretion was more frequently abnormal (P < 0.01) after fructose (68%) than HFCS (26%) in controls and patients. Fructose intolerance (i.e. abnormal breath test and symptoms) was more prevalent after fructose than HFCS in healthy subjects (25% vs 0%, P = 0.002) and patients (40% vs 7%, P = 0.062). Scores for several symptoms (e.g. bloating r = 0.35) were correlated (P ≤ 0.01) to peak breath hydrogen excretion after fructose but not HFCS; in the fructose group, this association did not differ between healthy subjects and patients. Symptoms were not significantly different after fructose compared to HFCS. Fructose intolerance is more prevalent with fructose alone than with HFCS in health and in IBS. The prevalence of fructose intolerance is not significantly different between health and IBS. Current methods for identifying fructose intolerance should be modified to more closely reproduce fructose ingestion in daily life. PMID:18221251

  8. Comparison of breath testing with fructose and high fructose corn syrups in health and IBS.

    PubMed

    Skoog, S M; Bharucha, A E; Zinsmeister, A R

    2008-05-01

    Although incomplete fructose absorption has been implicated to cause gastrointestinal symptoms, foods containing high fructose corn syrup (HFCS) contain glucose. Glucose increases fructose absorption in healthy subjects. Our hypothesis was that fructose intolerance is less prevalent after HFCS consumption compared to fructose alone in healthy subjects and irritable bowel syndrome (IBS). Breath hydrogen levels and gastrointestinal symptoms were assessed after 40 g of fructose (12% solution) prepared either in water or as HFCS, administered in double-blind randomized order on 2 days in 20 healthy subjects and 30 patients with IBS. Gastrointestinal symptoms were recorded on 100-mm Visual Analogue Scales. Breath hydrogen excretion was more frequently abnormal (P < 0.01) after fructose (68%) than HFCS (26%) in controls and patients. Fructose intolerance (i.e. abnormal breath test and symptoms) was more prevalent after fructose than HFCS in healthy subjects (25% vs. 0%, P = 0.002) and patients (40% vs. 7%, P = 0.062). Scores for several symptoms (e.g. bloating r = 0.35) were correlated (P < or = 0.01) to peak breath hydrogen excretion after fructose but not HFCS; in the fructose group, this association did not differ between healthy subjects and patients. Symptoms were not significantly different after fructose compared to HFCS. Fructose intolerance is more prevalent with fructose alone than with HFCS in health and in IBS. The prevalence of fructose intolerance is not significantly different between health and IBS. Current methods for identifying fructose intolerance should be modified to more closely reproduce fructose ingestion in daily life.

  9. Tidal Volume Single Breath Washout of Two Tracer Gases - A Practical and Promising Lung Function Test

    PubMed Central

    Singer, Florian; Stern, Georgette; Thamrin, Cindy; Fuchs, Oliver; Riedel, Thomas; Gustafsson, Per; Frey, Urs; Latzin, Philipp

    2011-01-01

    Background Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF6) and helium (He) using an ultrasonic flowmeter (USFM). Methods The tracer gas mixture contained 5% SF6 and 26.3% He, had similar total MM as air, and was applied for a single tidal breath in 13 healthy adults. The USFM measured MM, which was then plotted against expired volume. USFM and mass spectrometer signals were compared in six subjects performing three SBW. Repeatability and reproducibility of SBW, i.e., area under the MM curve (AUC), were determined in seven subjects performing three SBW 24 hours apart. Results USFM reliably measured MM during all SBW tests (n = 60). MM from USFM reflected SF6 and He washout patterns measured by mass spectrometer. USFM signals were highly associated with mass spectrometer signals, e.g., for MM, linear regression r-squared was 0.98. Intra-subject coefficient of variation of AUC was 6.8%, and coefficient of repeatability was 11.8%. Conclusion The USFM accurately measured relative changes in SF6 and He washout. SBW tests were repeatable and reproducible in healthy adults. We have developed a fast, reliable, and straightforward USFM based SBW method, which provides valid information on SF6 and He washout patterns during tidal breathing. PMID:21423739

  10. Measurement of human CYP1A2 induction by inhalation exposure to benzo(a)pyrene based on in vivo isotope breath method.

    PubMed

    Duan, Xiaoli; Shen, Guofeng; Yang, Hongbiao; Lambert, George; Wei, Fusheng; Zhang, Junfeng Jim

    2016-01-01

    Cytochrome P450 1A2 (CYP1A2) is an enzyme involved in the metabolic activation of certain carcinogens, and inducible by toxic substrates. To date, few studies have investigated in vivo CYP1A2 induction in humans and its relationship to polycylic aromatic hydrocarbons (PAHs) like benzo(a)pyrene (BaP). Non-smoking healthy male coke-oven workers (n = 30) were recruited as 'exposure' group, and non-smoking healthy office workers in the same city (n = 10) were selected as 'control' group, to test whether high inhalation exposure to PAHs can induce CYP1A2 activity in human livers. Significantly higher inhalation exposure of PAHs were found among the exposure group compared to the control. Inhalation BaP exposure concentration in the exposure group was more than 30 times higher than the control group (p < 0.001). However, the exposure group did not exhale significant higher levels of (13)CO2/(12)CO2 in breath samples (p = 0.81), and no significant relationship was found between the inhaled BaP concentration and the (13)CO2/(12)CO2 ratio (p = 0.91). A significant association was found between the (13)CO2/(12)CO2 exhalation and dietary BaP intake level. Hepatic CYP1A2 activity/induction level was not effected by inhaled BaP but was altered by ingestion of BaP.

  11. Long-term stability of ethanol solutions for breath-alcohol tests.

    PubMed

    Kucmanic, John

    2009-01-01

    Aqueous alcohol solutions in conjunction with a simulator are used commonly to calibrate and check the operation of breath-alcohol instruments. In Ohio, these solutions expire one year from the date of manufacture. This study was undertaken to review and report the stability of several batches of solution that had been manufactured from 2003 to 2007 and were statutorily expired. Eight batches of solution, each with a theoretical breath-alcohol target value of 0.100 g/210 L, were tested on paired Intoxilyzer 8000s using Guth model 590 simulators. This model of simulator required only 250 mL of solution per simulator. Therefore, each batch was evaluated by testing a single bottle of solution that had remained sealed since its manufacture. Five tests were performed on each instrument, and the acceptable criterion was limited to +/- 0.005 g/210 L of the established target value. A current batch of solution was also examined to verify the performance of the instrument before study sample testing commenced and at the completion of testing. All batches and bottles produced acceptable results within the acceptable limit for each target value. It can be concluded that the stability of the wet bath solution packaged in high-density polyethylene bottles with a theoretical concentration of 0.100 g/210 L is in excess of five years and surpasses the statutory expiration term of one year from the date of manufacture when stored at normal room temperatures.

  12. A nanomaterial-based breath test for distinguishing gastric cancer from benign gastric conditions

    PubMed Central

    Xu, Z-q; Broza, Y Y; Ionsecu, R; Tisch, U; Ding, L; Liu, H; Song, Q; Pan, Y-y; Xiong, F-x; Gu, K-s; Sun, G-p; Chen, Z-d; Leja, M; Haick, H

    2013-01-01

    Background: Upper digestive endoscopy with biopsy and histopathological evaluation of the biopsy material is the standard method for diagnosing gastric cancer (GC). However, this procedure may not be widely available for screening in the developing world, whereas in developed countries endoscopy is frequently used without major clinical gain. There is a high demand for a simple and non-invasive test for selecting the individuals at increased risk that should undergo the endoscopic examination. Here, we studied the feasibility of a nanomaterial-based breath test for identifying GC among patients with gastric complaints. Methods: Alveolar exhaled breath samples from 130 patients with gastric complaints (37 GC/32 ulcers / 61 less severe conditions) that underwent endoscopy/biopsy were analyzed using nanomaterial-based sensors. Predictive models were built employing discriminant factor analysis (DFA) pattern recognition, and their stability against possible confounding factors (alcohol/tobacco consumption; Helicobacter pylori) was tested. Classification success was determined (i) using leave-one-out cross-validation and (ii) by randomly blinding 25% of the samples as a validation set. Complementary chemical analysis of the breath samples was performed using gas chromatography coupled with mass spectrometry. Results: Three DFA models were developed that achieved excellent discrimination between the subpopulations: (i) GC vs benign gastric conditions, among all the patients (89% sensitivity; 90% specificity); (ii) early stage GC (I and II) vs late stage (III and IV), among GC patients (89% sensitivity; 94% specificity); and (iii) ulcer vs less severe, among benign conditions (84% sensitivity; 87% specificity). The models were insensitive against the tested confounding factors. Chemical analysis found that five volatile organic compounds (2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene) were significantly elevated in patients with GC and

  13. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  14. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  15. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  16. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  17. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the saliva... ATF. (b) As the STT or BAT, you must take the following steps when using the breath tube ASD:...

  18. Air-breathing aerospace plane development essential: Hypersonic propulsion flight tests

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.

    1994-01-01

    Hypersonic air-breathing propulsion utilizing scramjets can fundamentally change transatmospheric accelerators for low earth-to-orbit and return transportation. The value and limitations of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. It is proposed that near full-scale hypersonic propulsion flight tests are essential for developing a prototype hypersonic propulsion system and for developing computational-design technology so that it can be used for designing this system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests. A road map for achieving these objectives is also presented.

  19. Hypersonic propulsion flight tests as essential to air-breathing aerospace plane development

    NASA Technical Reports Server (NTRS)

    Mehta, U.

    1995-01-01

    Hypersonic air-breathing propulsion utilizing scramjets can fundamentally change transatmospheric acclerators for transportation from low Earth orbits (LEOs). The value and limitations of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. Near-full-scale hypersonic propulsion flight tests are essential for developing a prototype hypersonic propulsion system and for developing computation-design technology that can be used in designing that system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests. A road map for achieving these objectives is also presented.

  20. Hypersonic propulsion flight tests as essential to air-breathing aerospace plane development

    NASA Technical Reports Server (NTRS)

    Mehta, U.

    1995-01-01

    Hypersonic air-breathing propulsion utilizing scramjets can fundamentally change transatmospheric acclerators for transportation from low Earth orbits (LEOs). The value and limitations of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. Near-full-scale hypersonic propulsion flight tests are essential for developing a prototype hypersonic propulsion system and for developing computation-design technology that can be used in designing that system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests. A road map for achieving these objectives is also presented.

  1. Faecal hydrogen production in vitro as an indicator for in vivo hydrogen producing capability in the breath hydrogen test.

    PubMed

    Robb, T A; Goodwin, D A; Davidson, G P

    1985-11-01

    In the assessment of carbohydrate malabsorption, it is important to determine if a flat breath hydrogen test is a false negative result. Currently, the only reliable way to do this is with a lactulose test. We determined the reliability of assessing faecal hydrogen production as an indicator of an adequate in vivo hydrogen producing colonic bacterial flora. Unfortunately, the results clearly show that the incidence of falsely positive and negative faecal hydrogen production, when compared with in vivo lactulose testing, is so high that the simple faeces screening test is unsuitable for routine use. Until a simpler alternative is found, centres using the breath hydrogen test to determine carbohydrate malabsorption must continue to rely on lactulose breath testing when it is necessary to exclude potential false negative results.

  2. Specific 13C functional pathways as diagnostic targets in gastroenterology breath-tests: tricks for a correct interpretation.

    PubMed

    Pizzoferrato, M; Del Zompo, F; Mangiola, F; Lopetuso, L R; Petito, V; Cammarota, G; Gasbarrini, A; Scaldaferri, F

    2013-01-01

    Breath tests are non-invasive, non-radioactive, safe, simple and effective tests able to determine significant metabolic alterations due to specific diseases or lack of specific enzymes. Carbon isotope (13)C, the stable-non radioactive isotope of carbon, is the most used substrate in breath testing, in which (13)C/(12)C ratio is measured and expressed as a delta value, a differences between readings and a fixed standard. (13)C/(12)C ratio is measured with isotope ratio mass spectrometry or non-dispersive isotope-selective infrared spectrometer and generally there is a good agreement between these techniques in the isotope ratio estimation. (13)C/(12)C ratio can be expressed as static measurement (like delta over baseline in urea breath test) or as dynamic measurement as percent dose recovery, but more dosages are necessary. (13)C Breath-tests are involved in many fields of interest within gastroenterology, such as detection of Helicobacter pylori infection, study of gastric emptying, assessment of liver and exocrine pancreatic functions, determination of oro-caecal transit time, evaluation of absorption and to a lesser extend detection of bacterial overgrowth. The use of every single test in a clinical setting is vary depending on accuracy and substrate costs. This review is meant to present (13)C the meaning of (13)C/(12)C ratio and static and dynamic measure and, finally, the instruments dedicated to its use in gastroenterology. A brief presentation of (13)C breath tests in gastroenterology is also provided.

  3. Comparing past interglacials to understand atmospheric CO2 and carbon cycle dynamics using Antarctic ice core Δ13CO2 data

    NASA Astrophysics Data System (ADS)

    Schneider, R.; Schmitt, J.; Joos, F.; Fischer, H.

    2010-12-01

    Past atmospheric CO2 concentrations (Luethi et al., 2008) indicating a complex behavior of the global carbon cycle. During the last 800,000 years, nine warm periods are observed, which all differ in duration, absolute CO2 level, CO2 evolution, overshoot characteristics as well as the behavior during deglaciation and inception of glacial conditions. The stable carbon isotopic ratio of CO2 provides a tool to investigate the causes of those differences, as different carbon sources and sinks show different isotopic fractionation, which, in concert to coupled climate models, might allow a quantification of the changes in the carbon storage of major reservoirs (ocean, biosphere, sediments and atmosphere) and fluxes between them. A recently performed study on the atmospheric stable carbon isotopic ratio during the last 12,000 years (Elsig et al., 2009) show a slight increase in δ 13CO2 between 12-8,000 years accompanied by a decrease in CO2, and an almost constant δ 13CO2 level in parallel to the CO2 rise during the last 8,000 years. The early Holocene CO2 decline can be explained by an interplay of carbon uptake of the land biosphere and carbon release from the ocean in response to carbonate compensation of the terrestrial uptake during the last deglaciation. In contrast, the late Holocene CO2 increase is likely a combination of carbonate compensation of the earlier land-biosphere uptake, coral reef formation and a small decrease of the land-biosphere carbon inventory. An early human influence on the atmospheric CO2 level via deforestation and land use change proposed by Ruddiman (Ruddiman, 2003) was estimated to be small compared to other fluxes (Stocker et al., 2010). However, uncertainty remains regarding the amount and age of carbon stored in peat lands. Recently published data on that subject (Yu et al., 2010) suggest an increase in the storage of carbon in form of peat since the last glacial maximum, of up to 600 GtC. Taking this at face value this peat uptake

  4. Expanding analytical options in sports drug testing: Mass spectrometric detection of prohibited substances in exhaled breath.

    PubMed

    Thevis, Mario; Krug, Oliver; Geyer, Hans; Schänzer, Wilhelm

    2017-08-15

    Continuously refining and advancing the strategies and methods employed in sports drug testing is critical for efficient doping controls. Besides improving and expanding the spectrum of target analytes, alternative test matrices have warranted in-depth evaluation as they commonly allow for minimal-/non-invasive and non-intrusive sample collection. In this study, the potential of exhaled breath (EB) as doping control specimen was assessed. EB collection devices employing a non-woven electret-based air filter unit were used to generate test specimens, simulating a potential future application in doping controls. A multi-analyte sports drug testing approach configured for a subset of 12 model compounds that represent specific classes of substances prohibited in sports (anabolic agents, hormone and metabolic modulators, stimulants, and beta-blockers) was established using unispray liquid chromatography/tandem mass spectrometry (LC/MS/MS) and applied to spiked and elimination study EB samples. The test method was characterized concerning specificity, assay imprecision, and limits of detection. The EB collection device allowed for retaining and extracting all selected model compounds from the EB aerosol. Following elution and concentration, LC/MS/MS analysis enabled detection limits between 5 and 100 pg/filter and imprecisions ranging from 3% to 20% for the 12 selected model compounds. By means of EB samples from patients and participants of administration studies, the elimination of relevant compounds and, thus, their traceability in EB for doping control purposes, was investigated. Besides stimulants such as methylhexaneamine and pseudoephedrine, also the anabolic-androgenic steroid dehydrochloromethyltestosterone, the metabolic modulator meldonium, and the beta-blocker bisoprolol was detected in exhaled breath. The EB aerosol has provided a promising proof-of-concept suggesting the expansion of this testing strategy as a complement to currently utilized sports drug

  5. Rapid in vivo detection of isoniazid-sensitive Mycobacterium tuberculosis by breath test.

    PubMed

    Choi, Seong Won; Maiga, Mamoudou; Maiga, Mariama C; Atudorei, Viorel; Sharp, Zachary D; Bishai, William R; Timmins, Graham S

    2014-09-23

    There is urgent need for rapid, point-of-care diagnostic tools for tuberculosis (TB) and drug sensitivity. Current methods based on in vitro growth take weeks, while DNA amplification can neither differentiate live from dead organisms nor determine phenotypic drug resistance. Here we show the development and evaluation of a rapid breath test for isoniazid (INH)-sensitive TB based on detection of labelled N2 gas formed specifically from labelled INH by mycobacterial KatG enzyme. In vitro data show that the assay is specific, dependent on mycobacterial abundance and discriminates between INH-sensitive and INH-resistant (S315T mutant KatG) TB. In vivo, the assay is rapid with maximal detection of (15)N2 in exhaled breath of infected rabbits within 5-10 min. No increase in (15)N2 is detected in uninfected animals, and the increases in (15)N2 are dependent on infection dose. This test may allow rapid detection of INH-sensitive TB.

  6. Seasonal variations of the amount of carbon allocated to respiration after in situ 13CO2 pulse labelling of trees (Invited)

    NASA Astrophysics Data System (ADS)

    Epron, D.; Dannoura, M.; Ngao, J.; Plain, C.; Berveller, D.; Chipeaux, C.; Gerant, D.; Bosc, A.; Maillard, P.; Loustau, D.; Damesin, C.; Cats Project (Anr-07-Blan-0109)

    2010-12-01

    Soil and trunk respiration are the major sources of carbon from forest ecosystems to the atmosphere and they account for a large fraction of total ecosystem respiration. The amount of photosynthate allocated to respiration affects the growth of the tree and the potential for carbon sequestration of forest ecosystems. This study, aiming at understanding patterns of carbon allocation to respiration among species and seasons, consisted in pure 13CO2 labelling of the entire crown of three different tree species (beech, oak and pine) at distinct phenological stages between Sept 2008 and Feb 2010. 13C was then tracked for several weeks in soil and trunk CO2 efflux at high temporal resolution using tuneable diode laser absorption spectrometry (Plain et al. 2009). Recovery of 13C in trunk and soil CO2 efflux was observed a few couple of hours after the beginning of the labelling in oak and beech. There is a rapid transfer of 13C belowground with a maximum occurring within 2 to 4 days after labelling. Label was recovered at the same time in the respiration and in the biomass of both fine roots and microbes. Maximum recovery occurred earlier in beech and oak, while it happened later in Pine. Indeed, the velocity of phloem transport, calculated as the difference of time lags in 13C recovery in trunk respiration at different height, was around 0.10-0.2m/h in pine and around 0.2-1.2 m/h in oak and beech, reflecting difference in phloem anatomy between angiosperm and gymnosperm. The cumulated amount of label recovered in soil CO2 efflux 20 days after labelling varied among the seasons in all species, from 1 to 16% in beech, 2 to 11% in oak and 1 to 11% in pine. For all species, allocation to soil respiration was greater in early summer compared to spring, late summer and autumn. A compartmental analysis is further conducted to characterise functional pools of labelled substrates and storage compounds that contribute to both trunk and soil respiration. [Plain C, Gérant D

  7. Reporter phage and breath tests: emerging phenotypic assays for diagnosing active tuberculosis, antibiotic resistance, and treatment efficacy.

    PubMed

    Jain, Paras; Thaler, David S; Maiga, Mamoudou; Timmins, Graham S; Bishai, William R; Hatfull, Graham F; Larsen, Michelle H; Jacobs, William R

    2011-11-15

    The rapid and accurate diagnosis of active tuberculosis (TB) and its drug susceptibility remain a challenge. Phenotypic assays allow determination of antibiotic susceptibilities even if sequence data are not available or informative. We review 2 emerging diagnostic approaches, reporter phage and breath tests, both of which assay mycobacterial metabolism. The reporter phage signal, Green fluorescent protein (GFP) or β-galactosidase, indicates transcription and translation inside the recipient bacilli and its attenuation by antibiotics. Different breath tests assay, (1) exhaled antigen 85, (2) mycobacterial urease activity, and (3) detection by trained rats of disease-specific odor in sputum, have also been developed. When compared with culture, reporter phage assays shorten the time for initial diagnosis of drug susceptibility by several days. Both reporter phage and breath tests have promise as early markers to determine the efficacy of treatment. While sputum often remains smear and Mycobacterium tuberculosis DNA positive early in the course of efficacious antituberculous treatment, we predict that both breath and phage tests will rapidly become negative. If this hypothesis proves correct, phage assays and breath tests could become important surrogate markers in early bactericidal activity (EBA) studies of new antibiotics.

  8. The influence of breathing type, expiration and cervical posture on the performance of the cranio-cervical flexion test in healthy subjects.

    PubMed

    Cagnie, Barbara; Danneels, Lieven; Cools, Ann; Dickx, Nele; Cambier, Dirk

    2008-06-01

    The cranio-cervical flexion test (CCF-T) is used as a clinical evaluation tool for the deep cervical flexors (DCF). The influence of breathing type, expiration and cervical posture on the performance of the test is evaluated in asymptomatic subjects. Thirty volunteers participated in the study and were classified according to their breathing type: costo-diaphragmatic breathing type and upper costal breathing type. Sternocleidomastoid (SCM) electromyographic (EMG) activity was recorded during five incremental levels of CCF during normal breathing as well as during expiration. The cranio-vertebral angle of each subject was measured to quantify cervical posture. During normal inspiration, higher EMG activity of the SCM muscles was observed in subjects with an upper costal breathing pattern compared to costo-diaphragmatic breathing subjects. This difference was statistically significant (P< 0.05) at the three lowest stages of the test. In the upper costal breathing group a significantly lower EMG activity of the SCM muscles was observed while performing the CCF-T during slow expiration compared to normal breathing. No significant correlation was found between the cranio-vertebral angle and the EMG activity of the SCM muscles. Performing the CCF-T during slow expiration diminishes the activity of the SCM muscles in subjects with a predominantly upper costal breathing pattern. Using a costo-diaphragmatic breathing pattern while performing the test will optimize the performance. Studies on neck pain patients are required to further clarify this issue.

  9. Combined FTIR-micrometeorological techniques for long term flux measurements of greenhouse gases and their applicability for 13CO2 fluxes

    NASA Astrophysics Data System (ADS)

    Warneke, Thorsten; Caldow, Chris; Griffith, David

    2010-05-01

    Fourier Transform InfraRed (FTIR) spectrometry has been deployed for continuous long term flux measurements on a flat, homogeneous circular grass paddock in New South Wales, Australia. The rationale for using FTIR spectrometry is its capability to measure many species simultaneously. The flux measurement techniques combined with FTIR - spectrometry in this study were Disjunct Eddy Accumulation (DEA) and Flux-Gradient (FG). The fluxes of CO2 derived from the FTIR-DEA and FTIR-FG measurements agree well and have been validated by Eddy Covariance Licor measurements. Variations in the observed fluxes could be attributed to temperature increase and water availability over the 5 months measurement period. In addition to CO2, CH4, CO and N2O FTIR-spectrometry is also capable to measure 13CO2. The isotopic fluxes of CO2 allow to separate net ecosystem exchange of CO2 into its gross one-way component fluxes, ecosystem respiration and photosynthesis. It has been shown that it is possible to measure the isoflux of CO2.

  10. CO, NOx and 13CO2 as tracers for fossil fuel CO2: results from a pilot study in Paris during winter 2010

    NASA Astrophysics Data System (ADS)

    Lopez, M.; Schmidt, M.; Delmotte, M.; Colomb, A.; Gros, V.; Janssen, C.; Lehman, S. J.; Mondelain, D.; Perrussel, O.; Ramonet, M.; Xueref-Remy, I.; Bousquet, P.

    2013-08-01

    Measurements of the mole fraction of the CO2 and its isotopes were performed in Paris during the MEGAPOLI winter campaign (January-February 2010). Radiocarbon (14CO2) measurements were used to identify the relative contributions of 77% CO2 from fossil fuel consumption (CO2ff from liquid and gas combustion) and 23% from biospheric CO2 (CO2 from the use of biofuels and from human and plant respiration: CO2bio). These percentages correspond to average mole fractions of 26.4 ppm and 8.2 ppm for CO2ff and CO2bio, respectively. The 13CO2 analysis indicated that gas and liquid fuel contributed 70% and 30%, respectively, of the CO2 emission from fossil fuel use. Continuous measurements of CO and NOx and the ratios CO/CO2ff and NOx/CO2ff derived from radiocarbon measurements during four days make it possible to estimate the fossil fuel CO2 contribution over the entire campaign. The ratios CO/CO2ff and NOx/CO2ff are functions of air mass origin and exhibited daily ranges of 7.9 to 14.5 ppb ppm-1 and 1.1 to 4.3 ppb ppm-1, respectively. These ratios are consistent with different emission inventories given the uncertainties of the different approaches. By using both tracers to derive the fossil fuel CO2, we observed similar diurnal cycles with two maxima during rush hour traffic.

  11. IRAM 30 m Large Scale Survey of 12CO(2-1) and 13CO(2-1) Emission in the Orion Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Berné, O.; Marcelino, N.; Cernicharo, J.

    2014-11-01

    Using the IRAM 30 m telescope, we have surveyed a 1 × 0.°8 part of the Orion molecular cloud in the 12CO and 13CO (2-1) lines with a maximal spatial resolution of ~11'' and spectral resolution of ~0.4 km s-1. The cloud appears filamentary, clumpy, and with a complex kinematical structure. We derive an estimated mass of the cloud of 7700 M ⊙ (half of which is found in regions with visual extinctions AV below ~10) and a dynamical age for the nebula of the order of 0.2 Myr. The energy balance suggests that magnetic fields play an important role in supporting the cloud, at large and small scales. According to our analysis, the turbulent kinetic energy in the molecular gas due to outflows is comparable to turbulent kinetic energy resulting from the interaction of the cloud with the H II region. This latter feedback appears negative, i.e., the triggering of star formation by the H II region is inefficient in Orion. The reduced data as well as additional products such as the column density map are made available online (http://userpages.irap.omp.eu/~oberne/Olivier_Berne/Data).

  12. Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

    SciTech Connect

    Marshall, B.J.; Surveyor, I.

    1988-01-01

    Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 microCi (370 kBq) of /sup 14/C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of /sup 14/C collected at these times was expressed as: body weight X (% of administered dose of /sup 14/C in sample)/(mmol of CO/sub 2/ collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO/sub 2/ than patients who were not infected. The difference between infected patients and C. pylori negative control patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p less than 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy.

  13. Gravitational independence of single-breath washout tests in recumbent dogs

    NASA Technical Reports Server (NTRS)

    Tomioka, Shinichi; Kubo, Susumu; Guy, Harold J. B.; Prisk, G. K.

    1988-01-01

    The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

  14. Gravitational independence of single-breath washout tests in recumbent dogs

    NASA Technical Reports Server (NTRS)

    Tomioka, Shinichi; Kubo, Susumu; Guy, Harold J. B.; Prisk, G. K.

    1988-01-01

    The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

  15. Evaluation of the (14)C-urea breath test using indigenously produced (14)C-urea capsules and a modified technique for trapping exhaled breath: a pilot study.

    PubMed

    Tiwari, Bijaynath P; Nistala, Srinivas; Patil, Sanjay P; Kalgutkar, Deepak P; Jaychandran, Narath; Chander, Harish; Basu, Sandip

    2014-03-01

    The carbon urea breath test ((14)C-UBT) is a noninvasive technique used to detect Helicobacter pylori infection in patients presenting with dyspeptic symptoms. The present study was undertaken to determine the efficacy of indigenously produced (14)C-UBT capsules by the Board of Radiation and Isotope Technology, India. Thirty consecutive patients with dyspeptic symptoms were included in the study. After ingestion of capsules, breath samples were collected in a CO2-trapping solution to which a scintillation cocktail was added. After 24 h, the whole sample was counted in a liquid scintillation counter along with a standard of (14)C. The number of disintegrations of (14)C per minute in the breath sample was calculated. The results were compared with histopathological reports. Of 30 patients, 19 were positive and 11 were negative on (14)C-UBT. Histopathological reports confirmed 27 cases as positive and three as negative for H. pylori. Thus, the results of (14)C-UBT were concordant with histopathological results in 22/30 (73.3%) cases. Considering histopathology as the gold standard, the sensitivity, specificity, and positive predictive value of (14)C-UBT using indigenously produced capsules were found to be 70.33, 100, and 100%, respectively. On critical analysis of the discordant results, we observed that six patients had undergone H. pylori eradication therapy exactly 4 weeks before the test. When these six patients were excluded from the analysis, the sensitivity, specificity, and positive predictive value were found to be 90.05, 100, and 100%, respectively, which compared well with the values obtained using the standard procedure. The study demonstrates adequate efficacy of the indigenous methodology in newly diagnosed symptomatic patients with acid peptic disorders. The analyses of the results indicate that the test should be preferably employed after the recommended period of 1 month following completion of eradication therapy.

  16. Carbon-13 Urea Breath Test for Helicobacter Pylori Infection in Patients with Uninvestigated Ulcer-Like Dyspepsia

    PubMed Central

    Ling, D

    2013-01-01

    Background Dyspepsia is a condition defined by chronic pain or discomfort in the upper gastrointestinal tract that can be caused by Helicobacter pylori. The carbon-13 urea breath test (13C UBT) is a non-invasive test to detect H. pylori. Objectives We aimed to determine the diagnostic accuracy and clinical utility of the 13C UBT in adult patients with ulcer-like dyspepsia who have no alarm features. Data Sources A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2003 and 2012. Review Methods We abstracted the sensitivity and specificity, which were calculated against a composite reference standard. Summary estimates were obtained using bivariate random effects regression analysis. Results From 19 diagnostic studies, the 13C UBT summary estimates were 98.1% (95% confidence interval [CI], 96.3–99.0) for sensitivity and 95.1% (95% CI, 90.3–97.6) for specificity. In 6 studies that compared the 13C UBT with serology, the 113C UBT sensitivity was 95.0% (95% CI, 90.1–97.5) and specificity was 91.6 % (95% CI, 81.3–96.4). The sensitivity and specificity for serology were 92.9% (95% CI, 82.6–97.3) and 71.1% (95% CI, 63.8–77.5), respectively. In 1 RCT, symptom resolution, medication use, and physician visits were similar among the 13C UBT, serology, gastroscopy, or empirical treatment arms. However, patients tested with 13C UBT reported higher dyspepsia-specific quality of life scores. Limitations Processing of the 13C UBT results can vary according to many factors. Further, the studies showed significant heterogeneity and used different composite reference standards. Conclusions The 13C UBT is an accurate test with high sensitivity and specificity. Compared with serology, it has higher specificity. There is a paucity of data on the 13C UBT beyond test accuracy. Plain Language

  17. Gastric emptying of a liquid nutrient meal in the critically ill: relationship between scintigraphic and carbon breath test measurement.

    PubMed

    Chapman, M J; Besanko, L K; Burgstad, C M; Fraser, R J; Bellon, M; O'Connor, S; Russo, A; Jones, K L; Lange, K; Nguyen, N Q; Bartholomeusz, F; Chatterton, B; Horowitz, M

    2011-10-01

    It is assumed that delayed gastric emptying (GE) occurs frequently in critical illness; however, the prevalence of slow GE has not previously been assessed using scintigraphy. Furthermore, breath tests could potentially provide a convenient method of quantifying GE, but have not been validated in this setting. The aims of this study were to (i) determine the prevalence of delayed GE in unselected, critically ill patients and (ii) evaluate the relationships between GE as measured by scintigraphy and carbon breath test. Prospective observational study. Mixed medical/surgical intensive care unit. 25 unselected, mechanically ventilated patients (age 66 years (49-72); and 14 healthy subjects (age 62 years (19-84)). GE was measured using scintigraphy and (14)C-breath test. A test meal of 100 ml Ensure (standard liquid feed) labelled with (14)C octanoic acid and (99m)Technetium sulphur colloid was placed in the stomach via a nasogastric tube. Gastric 'meal' retention (scintigraphy) at 60, 120, 180 and 240 min, breath test t(50) (BTt(50)), and GE coefficient were determined. Of the 24 patients with scintigraphic data, GE was delayed at 120 min in 12 (50%). Breath tests correlated well with scintigraphy in both patients and healthy subjects (% retention at 120 min vs BTt(50); r(2)=0.57 healthy; r(2)=0.56 patients; p≤0.002 for both). GE of liquid nutrient is delayed in approximately 50% of critically ill patients. Breath tests correlate well with scintigraphy and are a valid method of GE measurement in this group.

  18. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one that... Alcohol Screening Tests § 40.243 What is the procedure for an alcohol screening test using an EBT or non...

  19. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one that... Alcohol Screening Tests § 40.243 What is the procedure for an alcohol screening test using an EBT or non...

  20. Validation of the 13C-urea breath test for use in cheetahs (Acinonyx jubatus) with Helicobacter.

    PubMed

    Chatfield, Jenifer; Citino, Scott; Munson, Linda; Konopka, Stanley

    2004-06-01

    Historically, therapeutic monitoring for prescribed eradication treatment of Helicobacter in cheetahs (Acinonyx jubatus) with associated gastritis has been accomplished only through endoscopic biopsies. The 13C-urea breath test (UBT) can offer an alternative to repeated biopsies for therapeutic monitoring. Five male and five female cheetahs and one male Sumatran tiger (Panthera tigris) were studied. All were clinically healthy before and after this investigation. Breath samples of end-tidal expiration were taken before and after administration of a 13C-enriched urea solution through a gastroesophageal tube. Twenty-milliliter breath samples were taken at 10, 20, 30, and 40 min after administration of the urea solution. The results of the breath analysis were compared with the results of rapid urease testing, histopathologic examination, and impression smears of gastric biopsies taken at the time of the breath test. The sensitivity and specificity for the 13C-UBT in this investigation were 100%. and the positive predictive value and negative predictive value were both 100%. Although the 13C-UBT is a good noninvasive diagnostic tool for monitoring the presence of Helicobacter sp. in the gastric mucosa, endoscopy should still be used for initial diagnosis and grading of gastritis and for monitoring the progression of disease in cheetahs. The 13C-UBT is a valuable, simple, accurate, and sensitive tool for monitoring eradication of Helicobacter during therapy for clinical gastritis.

  1. Production of hyperpolarized 13CO2 from [1-13C]pyruvate in perfused liver does reflect total anaplerosis but is not a reliable biomarker of glucose production

    PubMed Central

    Moreno, Karlos X.; Moore, Christopher L.; Burgess, Shawn C.; Sherry, A. Dean; Malloy, Craig R.

    2015-01-01

    In liver, 13CO2 can be generated from [1-13C] pyruvate via pyruvate dehydrogenase or anaplerotic entry of pyruvate into the TCA cycle followed by decarboxylation at phosphoenolpyruvate carboxykinase (PEPCK), the malic enzyme, isocitrate dehydrogenase, or α-ketoglutarate dehydrogenase. The purpose of this study was to determine the relative importance of these pathways in production of hyperpolarized (HP) 13CO2 after administration of hyper-polarized pyruvate in livers supplied with a fatty acid plus substrates for gluconeogenesis. Isolated mouse livers were perfused with a mixture of thermally-polarized 13C-enriched pyruvate, lactate and octanoate in various combinations prior to exposure to HP pyruvate. Under all perfusion conditions, HP malate, aspartate and fumarate were detected within ~ 3 s showing that HP [1-13C]pyruvate is rapidly converted to [1-13C]oxaloacetate which can subsequently produce HP 13CO2 via decarboxylation at PEPCK. Measurements using HP [2-13C]pyruvate allowed the exclusion of reactions related to TCA cycle turnover as sources of HP 13CO2. Direct measures of O2 consumption, ketone production, and glucose production by the intact liver combined with 13C isotopomer analyses of tissue extracts yielded a comprehensive profile of metabolic flux in perfused liver. Together, these data show that, even though the majority of HP 13CO2 derived from HP [1-13C]pyruvate in livers exposed to fatty acids reflects decarboxylation of [4-13C]oxaloacetate (PEPCK) or [4-13C]malate (malic enzyme), the intensity of the HP 13CO2 signal is not proportional to glucose production because the amount of pyruvate returned to the TCA cycle via PEPCK and pyruvate kinase is variable, depending upon available substrates. PMID:26543443

  2. Production of hyperpolarized (13)CO2 from [1-(13)C]pyruvate in perfused liver does reflect total anaplerosis but is not a reliable biomarker of glucose production.

    PubMed

    Moreno, Karlos X; Moore, Christopher L; Burgess, Shawn C; Sherry, A Dean; Malloy, Craig R; Merritt, Matthew E

    2015-10-01

    In liver, (13)CO2 can be generated from [1-(13)C] pyruvate via pyruvate dehydrogenase or anaplerotic entry of pyruvate into the TCA cycle followed by decarboxylation at phosphoenolpyruvate carboxykinase (PEPCK), the malic enzyme, isocitrate dehydrogenase, or α-ketoglutarate dehydrogenase. The purpose of this study was to determine the relative importance of these pathways in production of hyperpolarized (HP) (13)CO2 after administration of hyper-polarized pyruvate in livers supplied with a fatty acid plus substrates for gluconeogenesis. Isolated mouse livers were perfused with a mixture of thermally-polarized (13)C-enriched pyruvate, lactate and octanoate in various combinations prior to exposure to HP pyruvate. Under all perfusion conditions, HP malate, aspartate and fumarate were detected within ~ 3 s showing that HP [1-(13)C]pyruvate is rapidly converted to [1-(13)C]oxaloacetate which can subsequently produce HP (13)CO2 via decarboxylation at PEPCK. Measurements using HP [2-(13)C]pyruvate allowed the exclusion of reactions related to TCA cycle turnover as sources of HP (13)CO2. Direct measures of O2 consumption, ketone production, and glucose production by the intact liver combined with (13)C isotopomer analyses of tissue extracts yielded a comprehensive profile of metabolic flux in perfused liver. Together, these data show that, even though the majority of HP (13)CO2 derived from HP [1-(13)C]pyruvate in livers exposed to fatty acids reflects decarboxylation of [4-(13)C]oxaloacetate (PEPCK) or [4-(13)C]malate (malic enzyme), the intensity of the HP (13)CO2 signal is not proportional to glucose production because the amount of pyruvate returned to the TCA cycle via PEPCK and pyruvate kinase is variable, depending upon available substrates.

  3. (14C)Aminopyrine breath test in chronic liver disease: preliminary diagnostic implications

    SciTech Connect

    Burnstein, A.V.; Galambos, J.T.

    1981-12-01

    The (14C)aminopyrine breath test (APBT) score, an estimate of hepatic mixed-oxidase function, was evaluated in 21 consecutive patients wih active nonalcoholic chronic liver diseases. Ten had primary biliary cirrhosis (PBC) and 11 had chronic active hepatitis (CAH). The APBT score was normal or elevated in patients with PBC (P less than 0.001), and lower than normal in CAH patients (P less than 0.01); 10.5 +/- 1.6 and 3.5 +/- 1.86, respectively, vs control 7.65 +/- 1.15 (mean +/- SD). The 11 patients with CAH included two middle-aged women who displayed ambiguous severe intrahepatic cholestasis. There was no overlap between the APBT scores of the 10 PBC and 11 CAH patients. These initial data suggest that the APBT may be helpful in the differentiation of PBC and CAH, including misleading cholestatic forms of CAH.

  4. Potential sources of 2-aminoacetophenone to confound the Pseudomonas aeruginosa breath test, including analysis of a food challenge study.

    PubMed

    Scott-Thomas, Amy; Pearson, John; Chambers, Stephen

    2011-12-01

    2-Aminoacetophenone can be detected in the breath of Pseudomonas aeruginosa colonized cystic fibrosis patients; however, low levels were also detected in a small proportion of healthy subjects. It was hypothesized that food, beverages, cosmetics or medications could be a source of contamination of 2-aminoacetophenone in breath. To determine the potential confounding of these products on 2-aminoacetophenone breath analysis, screening for this volatile was performed in the laboratory by gas chromatography/mass spectrometry and a food challenge study carried out. 2-Aminoacetophenone was detected in four of the 78 samples tested in vitro: corn chips and canned tuna (high pmol mol(-1)) and egg white and one of the three beers (low pmol mol(-1)). No 2-aminoacetophenone was detected in the CF medication or cosmetics tested. Twenty-eight out of 30 environmental air samples were negative for 2-aminoacetophenone (below 50 pmol mol(-1)). A challenge study with ten healthy subjects was performed to determine if 2-aminoacetophenone from corn chips was detectable on the breath after consumption. Analysis of mixed breath samples reported that the levels of 2-aminoacetophenone were immediately elevated after corn chip consumption, but after 2 h the level of 2-aminoacetophenone had reduced back to the 'baseline' for each subject.

  5. Carbon Allocation of 13CO2-labeled Photoassimilate in Larix gmelinii Saplings - A Physiological Basis for Isotope Dendroclimatology in Eastern Siberia.

    NASA Astrophysics Data System (ADS)

    Kagawa, A.; Sugimoto, A.; Maximov, T. C.

    2006-12-01

    Tree-ring density and widths have been successfully used to reconstruct summer temperatures in high- northern latitudes, although a discrepancy between tree-growth and temperature has been found for recent decades. The so-called "reduced sensitivity" of tree rings to summer temperatures has been observed especially strongly in northern Siberia (Briffa et al., 1998) and drought stress (increased water use efficiency) arose from global warming and/or increasing CO2 are suggested as causes (Barber et al. 2000, Saurer et al. 2004). By using carbon isotope ratio as an indicator of drought stress and ring-width/density as indicators of growth, we can clarify how drought stress caused by recent global warming affects wood formation of Siberian trees. However, isotope dendroclimatology is still in its infancy and our understanding of basic physiological processes of isotope signal transfer from leaves to tree rings is insufficient. In order to understand translocation, storage, and allocation of photoassimilate to different organs of trees, we pulse- labeled ten L. gmelinii growing in a continuous permafrost zone with stable 13CO2. We studied seasonal course of carbon allocation patterns of photoassimilate among needles, branches, stem and roots and also how spring, summer, and autumn photoassimilate is later used for both earlywood and latewood formation. About half of the carbon in new needles was derived from stored material. The starch pool in non- needle parts, which can be used for xylem formation, drew about 43 percent of its carbon from previous year's photoassimilate, suggesting that carbon storage is the key mechanism behind autocorrelation in (isotope) dendroclimatology. Analysis of intra-annual 13C of the tree rings formed after the labeling revealed that earlywood contained photoassimilate from the previous summer and autumn as well as from the current spring. Latewood was mainly composed of photoassimilate from the current year's summer/autumn, although it

  6. Quantifying protein synthesis and degradation in Arabidopsis by dynamic 13CO2 labeling and analysis of enrichment in individual amino acids in their free pools and in protein.

    PubMed

    Ishihara, Hirofumi; Obata, Toshihiro; Sulpice, Ronan; Fernie, Alisdair R; Stitt, Mark

    2015-05-01

    Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied (13)CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%-4% d(-1)), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark. © 2015 American Society of Plant Biologists. All Rights Reserved.

  7. Measuring and modelling the intra-day variability of the 13CO2 & 12CO2 vertical soil profile production in a Scots pine forest

    NASA Astrophysics Data System (ADS)

    Longdoz, Bernard; Goffin, Stéphanie; Parent, Florian; Plain, Caroline; Epron, Daniel; Wylock, Christophe; Haut, Benoit; Aubinet, Marc; Maier, Martin

    2015-04-01

    Vertical profile of CO2 production (Ps) and transport, as well as their isotopic discrimination (13CO2/12CO2) should be considered to improve the soil CO2 efflux (Fs) mechanistic understanding and especially its short-term temporal variations. In this context, we propose a new methodology able to measure continuously and simultaneously Fs, the vertical soil CO2 concentration ([CO2]) profile and their respective isotopic signature (δFs and δCO2) [1]. The Ps of the different soil layers and their isotopic signature (δPs) can then be determined from these measurements by an approach considering diffusion as the only gas transport. A field campaign was conducted with this device at the Scots Pine Hartheim forest (Germany). The results [2] show (i) a Ps dependence on local temperature specific for each layer, (ii) an enrichment of δPs with soil drought, (iii) Fs and [CO2] large intra-day fluctuations non explained by the soil temperature and moisture. These fluctuations can be generated by other processes creating Ps and/or transport variability. To investigate about the nature of these processes, some sensitivity analyses have been performed with a soil CO2 model simulating both production and transport. The impacts of the introduction of advection, dispersion and phloem pressure concentration wave (through dependence of Ps on vapour pressure deficit) on intra-day Fs and [CO2] variations have been quantified. We conclude that these variations are significantly better represented when the phloem pressure wave expression is included in the simulations. The study of the processes related to CO2 production seems to be a better option than an investigation about transport to explain the intra-day Fs variability.

  8. Biosphere-atmosphere gross carbon exchange flux and the δ13CO2 and Δ14CO2 disequilibria constrained by the biospheric excess radiocarbon inventory

    NASA Astrophysics Data System (ADS)

    Naegler, Tobias; Levin, Ingeborg

    2009-09-01

    Estimates of the global biospheric excess 14C inventory IB14,E from Naegler and Levin (2009) were used to constrain the age distribution a(τ) in heterotrophically respired CO2 with a simple (radio)carbon model of the global biosphere. Subsequently, a(τ) could be used to estimate the global gross carbon exchange FeqC (net primary productivity, NPP, and heterotrophic respiration) between atmosphere and biosphere as well as both the δ13C and Δ14C signatures in heterotrophically respired CO2 (δ13CRH and Δ14CRH, respectively). Our estimates of FeqC range from 41 to 64 petagrams carbon per year (Pg C a-1), with a best estimate of 55 Pg C a-1. The uncertainty of this value is dominated by the uncertainties of IB14,E and of the net biospheric uptake of anthropogenic CO2. Limitations intrinsic to our approach as well as uncertainties in effective global average atmospheric Δ14CO2 add an uncertainty of ±3 Pg C a-1. The δ13CRH of heterotrophically respired CO2 lags the δ13C of assimilated CO2 by ˜10-17 years. This leads to a somewhat smaller estimate of the biospheric 13CO2 disequilibrium flux than previously assumed. Δ14CRH increased from ˜-20‰ in the early 1950s to maximum values of 300-325‰ in the late 1960s/early 1970s. In the 1980s, when the maximum IB14,E occurred, Δ14CRH was in a transient equilibrium with the atmosphere. The Δ14C disequilibrium between atmosphere and biosphere increased to Δ14CDIS = 20-50‰ in the mid-1990s, before it dropped to 15-40‰ in 2005.

  9. Effects of season and nitrogen supply on the partitioning of recently fixed carbon in understory vegetation using a 13CO2 pulse labeling technique

    NASA Astrophysics Data System (ADS)

    Hasselquist, Niles; Metcalfe, Daniel; Högberg, Peter

    2013-04-01

    Vegetation research in boreal forests has traditionally been focused on trees, with little attention given to understory vegetation. However, understory vegetation has been identified as a key driver for the functioning of boreal forests and may play an important role in the amount of carbon (C) that is entering and leaving these forested ecosystems. We conducted a large-scale 13C pulse labeling experiment to better understand how recently fixed C is allocated in the understory vegetation characteristic of boreal forests. We used transparent plastic chambers to pulse label the understory vegetation with enriched 13CO2 in the early (June) and late (August) growing seasons. This study was also replicated across a nitrogen (N) fertilization treatment to better understand the effects of N availability on C allocation patterns. We present data on the amount of 13C label found in different components of the understory vegetation (i.e. leaves, stems, lichens, mosses, rhizomes and fine roots) as well as CO2 efflux. Additionally, we provide estimates of C residence time (MRT) among the different components and examine how MRT of C is affected by seasonality and N availability. Seasonality had a large effect on how recently fixed C is allocated in understory vegetation, whereas N fertilization influenced the MRT of C in the different components of ericaceous vegetation. Moreover, there was a general trend that N additions increased the amount of 13C in CO2 efflux compared to the amount of 13C in biomass, suggesting that N fertilization may lead to an increase in the utilization of recently fixed C, whereas N-limitation promotes the storage of recently fixed C.

  10. Rapid, Long-term Monitoring of CO2 Concentration and δ13CO2 at CCUS Sites Allows Discrimination of Leakage Patterns from Natural Background Values

    NASA Astrophysics Data System (ADS)

    Galfond, B.; Riemer, D. D.; Swart, P. K.

    2014-12-01

    In order for Carbon Capture Utilization and Storage (CCUS) to gain wide acceptance as a method for mitigating atmospheric CO2 concentrations, schemes must be devised to ensure that potential leakage is detected. New regulations from the US Environmental Protection Agency require monitoring and accounting for Class VI injection wells, which will remain a barrier to wide scale CCUS deployment until effective and efficient monitoring techniques have been developed and proven. Monitoring near-surface CO2 at injection sites to ensure safety and operational success requires high temporal resolution CO2 concentration and carbon isotopic (δ13C) measurements. The only technologies currently capable of this rapid measurement of δ13C are optical techniques such as Cavity Ringdown Spectroscopy (CRDS). We have developed a comprehensive remote monitoring approach using CRDS and a custom manifold system to obtain accurate rapid measurements from a large sample area over an extended study period. Our modified Picarro G1101-i CRDS allows for automated rapid and continuous field measurement of δ13CO2 and concentrations of relevant gas species. At our field site, where preparations have been underway for Enhanced Oil Recovery (EOR) operations, we have been able to measure biogenic effects on a diurnal scale, as well as variation due to precipitation and seasonality. Taking these background trends into account, our statistical treatment of real data has been used to improve signal-to-noise ratios by an order of magnitude over published models. Our system has proven field readiness for the monitoring of sites with even modest CO2 fluxes.

  11. Consensus statement for inert gas washout measurement using multiple- and single- breath tests.

    PubMed

    Robinson, Paul D; Latzin, Philipp; Verbanck, Sylvia; Hall, Graham L; Horsley, Alexander; Gappa, Monika; Thamrin, Cindy; Arets, Hubertus G M; Aurora, Paul; Fuchs, Susanne I; King, Gregory G; Lum, Sooky; Macleod, Kenneth; Paiva, Manuel; Pillow, Jane J; Ranganathan, Sarath; Ranganathan, Sarah; Ratjen, Felix; Singer, Florian; Sonnappa, Samatha; Stocks, Janet; Subbarao, Padmaja; Thompson, Bruce R; Gustafsson, Per M

    2013-03-01

    Inert gas washout tests, performed using the single- or multiple-breath washout technique, were first described over 60 years ago. As measures of ventilation distribution inhomogeneity, they offer complementary information to standard lung function tests, such as spirometry, as well as improved feasibility across wider age ranges and improved sensitivity in the detection of early lung damage. These benefits have led to a resurgence of interest in these techniques from manufacturers, clinicians and researchers, yet detailed guidelines for washout equipment specifications, test performance and analysis are lacking. This manuscript provides recommendations about these aspects, applicable to both the paediatric and adult testing environment, whilst outlining the important principles that are essential for the reader to understand. These recommendations are evidence based, where possible, but in many places represent expert opinion from a working group with a large collective experience in the techniques discussed. Finally, the important issues that remain unanswered are highlighted. By addressing these important issues and directing future research, the hope is to facilitate the incorporation of these promising tests into routine clinical practice.

  12. Mosapride Accelerates the Delayed Gastric Emptying of High-Viscosity Liquids: A Crossover Study Using Continuous Real-Time 13C Breath Test (BreathID System)

    PubMed Central

    Sakamoto, Yasunari; Sekino, Yusuke; Yamada, Eiji; Ohkubo, Hidenori; Higurashi, Takuma; Sakai, Eiji; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Nonaka, Takashi; Ikeda, Tamon; Fujita, Koji; Yoneda, Masato; Koide, Tomoko; Takahashi, Hirokazu; Goto, Ayumu; Abe, Yasunobu; Gotoh, Eiji; Maeda, Shin; Nakajima, Atsushi

    2011-01-01

    Background/Aims The administration of liquid nutrients to patients is often accompanied by complications such as gastroesophageal reflux. To prevent gastroesophageal reflux, high-viscosity liquid meals are used widely, however, it still remains controversial whether high-viscosity liquid meals have any effect on the rate of gastric emptying. The present study was conducted with the aim of determining whether high-viscosity liquid meals had any effect on the rate of gastric emptying and mosapride might accelerate the rate of gastric emptying of high-viscosity liquid meals. Methods Six healthy male volunteers underwent 3 tests at intervals of > 1 week. After fasting for > 8 hours, each subject received one of three test meals (liquid meal only, high-viscosity liquid meal [liquid meal plus pectin] only, or high-viscosity liquid meal 30 minutes after intake of mosapride). A 13C-acetic acid breath test was performed, which monitored the rate of gastric emptying for 4 hours. Using the Oridion Research Software (β version), breath test parameters were calculated. The study parameters were examined for all the 3 test conditions and compared using the Freidman test. Results Gastric emptying was significantly delayed following intake of a high-viscosity liquid meal alone as compared with a liquid meal alone; however, intake of mosapride prior to a high-viscosity liquid meal was associated with a significantly accelerated rate of gastric emptying as compared with a high-viscosity liquid meal alone. Conclusions This study showed that high-viscosity liquid meals delayed gastric emptying: however, mosapride recovered the delayed rate of gastric emptying by high-viscosity liquid meals. PMID:22148109

  13. Effect of posture on (13)C-urea breath test in partial gastrectomy patients.

    PubMed

    Yin, Shu-Ming; Zhang, Fan; Shi, Dong-Mei; Xiang, Ping; Xiao, Li; Huang, Yi-Qin; Zhang, Gan-Sheng; Bao, Zhi-Jun

    2015-12-07

    To investigate whether posture affects the accuracy of (13)C-urea breath test ((13)C-UBT) for Helicobacter pylori (H. pylori) detection in partial gastrectomy patients. We studied 156 consecutive residual stomach patients, including 76 with H. pylori infection (infection group) and 80 without H. pylori infection (control group). H. pylori infection was confirmed if both the rapid urease test and histology were positive during gastroscopy. The two groups were divided into four subgroups according to patients' posture during the (13)C-UBT: subgroup A, sitting position; subgroup B, supine position; subgroup C, right lateral recumbent position; and subgroup D, left lateral recumbent position. Each subject underwent the following modified (13)C-UBT: 75 mg of (13)C-urea (powder) in 100 mL of citric acid solution was administered, and a mouth wash was performed immediately; breath samples were then collected at baseline and at 5-min intervals up to 30 min while the position was maintained. Seven breath samples were collected for each subject. The cutoff value was 2.0‰. The mean delta over baseline (DOB) values in the subgroups of the infection group were similar at 5 min (P > 0.05) and significantly higher than those in the corresponding control subgroups at all time points (P < 0.01). In the infection group, the mean DOB values in subgroup A were higher than those in other subgroups within 10 min and peaked at the 10-min point (12.4‰ ± 2.4‰). The values in subgroups B and C both reached their peaks at 15 min (B, 13.9‰ ± 1.5‰; C, 12.2‰ ± 1.7‰) and then decreased gradually until the 30-min point. In subgroup D, the value peaked at 20 min (14.7‰ ± 1.7‰). Significant differences were found between the values in subgroups D and B at both 25 min (t = 2.093, P = 0.043) and 30 min (t = 2.141, P = 0.039). At 30 min, the value in subgroup D was also significantly different from those in subgroups A and C (D vs C: t = 6.325, P = 0.000; D vs A: t = 5.912, P = 0

  14. [Cardiopulmonary exercise testing in chronic obstructive pulmonary disease (COPD) - breath-functional characterization and disease severity assessment].

    PubMed

    Mühle, A; Obst, A; Winkler, J; Ewert, R

    2015-09-01

    COPD is a heterogeneous disease with a wide range of clinical phenotypes and breath-functional dysfunctions. Cardiopulmonary exercise testing (CPET) allows describing all component parts of breathing and determining exercise capacity and the mechanisms of exercise limitation. From these aspects 64 COPD patient stages II, III and IV according to the conventional GOLD classification were examined by means of CPET to evaluate whether CPET can provide a better functional characterization of COPD than the standard investigation procedures in pulmonary practice.We could show that in pulmonary practice CPET is safely and effectively practicable in stable COPD patients of all GOLD stages. This method allowed a clinical and prognostic disease severity assessment of all patients, proving important differences of peak oxygen uptake in each GOLD stage, so that patients in spite of identical GOLD disease severity were to be assigned to different prognostic groups according CPET criteria. Furthermore, we found relevant differences of individual breath-functional patterns in exercise, which can neither be objectified nor be prognosticated by standard investigation procedures at rest.Therefore CPET allows, aside from an objective clinical and prognostic disease severity assessment, also a breath-functional evaluation in a subtly way in COPD patients reflecting the multidimensional background of the disease with variable dysfunctions in pulmonary ventilation, gas exchange, circulation and muscular function as well as associated cardio vascular comorbidities. The breath-functional phenotyping of the COPD patient seems to be meaningful in particular for an individualised therapy management.

  15. 13C-breath tests for sucrose digestion in congenital sucrase isomaltase-deficient and sacrosidase-supplemented patients

    USDA-ARS?s Scientific Manuscript database

    Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is ...

  16. Impact of hydrogen breath testing on diagnosis, management, and clinical outcome in children with chronic functional GI symptoms

    USDA-ARS?s Scientific Manuscript database

    Chronic functional gastrointestinal (GI) symptoms (e.g. abdominal pain) in children may have numerous etiologies including carbohydrate malabsorption and small bowel bacterial overgrowth (SBBO). Hydrogen breath testing (HBT) frequently is used as a modality to evaluate for these two diagnoses. Howev...

  17. Solubility testing of actinides on breathing-zone and area air samples

    SciTech Connect

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L.

    1996-02-01

    A solubility testing method for several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{reg_sign}) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of U{sub 3}O{sub 8}. Profiles developed for U{sub 3}O{sub 8} samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills.

  18. The global carbon cycle over the last millennium: implications of the latest Law Dome and South Pole firn and ice core records of CO2 and δ13CO2

    NASA Astrophysics Data System (ADS)

    Trudinger, C. M.; Rubino, M.; Etheridge, D. M.; Raupach, M. R.; Harman, I. N.

    2012-12-01

    The Law Dome δ 13CO2 ice core record has recently been revised and merged with new firn and ice core measurements. Here we present calculations with a globally-aggregated carbon cycle model looking at both natural variability and the industrial perturbation in CO2 and δ 13CO2. We investigate the use of observations of CO2, {}13CO2 and {}14CO2 to calibrate the Simple Carbon-Climate Model (SCCM), including the implications of the slightly lower preindustrial δ 13C levels in the latest record. We also present a Kalman filter double deconvolution that uses CO2 and δ 13CO2 measurements to infer net fluxes of CO2 between the atmosphere, land and oceans, focussing on decadal variability over the industrial period and century-scale variations back to 1000 AD. We will compare the results of the double deconvolution with calculations of SCCM forced with temperature variations to improve our understanding of the sensitivity of land and ocean carbon fluxes to climate on different timescales.

  19. Diagnosis of Helicobacter pylori infection by means of reduced-dose ¹³C-urea breath test and early sampling of exhaled breath.

    PubMed

    Pacheco, Sylmara L M; Ogata, Silvio K; Machado, Rodrigo S; Patrício, Francy Reis da Silva; Pardo, Mario L E; Kawakami, Elisabete

    2013-11-01

    The aim of this study was to evaluate the accuracy of reduced-dose ¹³C-urea breath test (¹³C-UBT) and early sampling of exhaled breath for the detection of Helicobacter pylori infection in children and adolescents. Patients up to 20 years old that underwent upper gastrointestinal endoscopy with gastric biopsies were included. The ¹³C-UBT was performed after a 4-hour fasting period with 4 points of collection: baseline (T₀), and at 10, 20, and 30 minutes (T₁₀, T₂₀, and T₃₀) after ingestion of 25 mg ¹³C-urea diluted in 100 mL of apple juice. The infection status was defined through 3 invasive methods, and a patient was considered infected with a positive culture or concomitant positive histology and rapid urease test. The absence of infection was defined by all negative histology, rapid urease test, and culture. Analysis of exhaled breath samples was performed with an isotope-selective infrared spectrometer. A receiver-operating characteristic curve analysis was done to define cutoff delta over baseline (DOB) values. A total of 129 patients between the ages of 2.1 and 19 years (median 11.6 years; mean age ± standard deviation 11.5 ± 3.8 years; F:M 85:44) were included. The prevalence of infection was 41.1%. The sensitivity (S) and specificity (Sp) were at T₁₀ (cutoff DOB 2.55‰), S 94.7% (95% confidence interval [CI] 90.9-98.5) and Sp 96.8% (95% CI 93.4-100); at T₂₀ (DOB 2.5‰), S 96.2% (95% CI 92.9-99.5) and Sp 96.1% (95% CI 93.7-99.8); and at T₃₀ (DOB 1.6‰), S 96.2% (95% CI 92.9-99.5) and Sp 94.7% (95% CI 90.8-98.6). Low-dose ¹³C-UBT with early sampling is accurate for diagnosing H pylori infection in children and adolescents.

  20. In situ 13CO2 pulse labelling of field-grown eucalypt trees revealed the effects of potassium nutrition and throughfall exclusion on phloem transport of photosynthetic carbon.

    PubMed

    Epron, Daniel; Cabral, Osvaldo Machado Rodrigues; Laclau, Jean-Paul; Dannoura, Masako; Packer, Ana Paula; Plain, Caroline; Battie-Laclau, Patricia; Moreira, Marcelo Zacharias; Trivelin, Paulo Cesar Ocheuze; Bouillet, Jean-Pierre; Gérant, Dominique; Nouvellon, Yann

    2016-01-01

    Potassium (K) is an important limiting factor of tree growth, but little is known of the effects of K supply on the long-distance transport of photosynthetic carbon (C) in the phloem and of the interaction between K fertilization and drought. We pulse-labelled 2-year-old Eucalyptus grandis L. trees grown in a field trial combining K fertilization (+K and -K) and throughfall exclusion (+W and -W), and we estimated the velocity of C transfer by comparing time lags between the uptake of (13)CO2 and its recovery in trunk CO2 efflux recorded at different heights. We also analysed the dynamics of the labelled photosynthates recovered in the foliage and in the phloem sap (inner bark extract). The mean residence time of labelled C in the foliage was short (21-31 h). The time series of (13)C in excess in the foliage was affected by the level of fertilization, whereas the effect of throughfall exclusion was not significant. The velocity of C transfer in the trunk (0.20-0.82 m h(-1)) was twice as high in +K trees than in -K trees, with no significant effect of throughfall exclusion except for one +K -W tree labelled in the middle of the drought season that was exposed to a more pronounced water stress (midday leaf water potential of -2.2 MPa). Our results suggest that besides reductions in photosynthetic C supply and in C demand by sink organs, the lower velocity under K deficiency is due to a lower cross-sectional area of the sieve tubes, whereas an increase in phloem sap viscosity is more likely limiting phloem transport under drought. In all treatments, 10 times less (13)C was recovered in inner bark extracts at the bottom of the trunk when compared with the base of the crown, suggesting that a large part of the labelled assimilates has been exported out of the phloem and replaced by unlabelled C. This supports the 'leakage-retrieval mechanism' that may play a role in maintaining the pressure gradient between source and sink organs required to sustain high

  1. The effect of physical back-diffusion of 13CO2 tracer on the coupling between photosynthesis and soil CO2 efflux in grassland.

    PubMed

    Burri, Susanne; Sturm, Patrick; Baur, Thomas; Barthel, Matti; Knohl, Alexander; Buchmann, Nina

    2014-01-01

    Pulse labelling experiments provide a common tool to study short-term processes in the plant-soil system and investigate below-ground carbon allocation as well as the coupling of soil CO(2) efflux to photosynthesis. During the first hours after pulse labelling, the measured isotopic signal of soil CO(2) efflux is a combination of both physical tracer diffusion into and out of the soil as well as biological tracer release via root and microbial respiration. Neglecting physical back-diffusion can lead to misinterpretation regarding time lags between photosynthesis and soil CO(2) efflux in grassland or any ecosystem type where the above-ground plant parts cannot be labelled in gas-tight chambers separated from the soil. We studied the effects of physical (13)CO(2) tracer back-diffusion in pulse labelling experiments in grassland, focusing on the isotopic signature of soil CO(2) efflux. Having accounted for back-diffusion, the estimated time lag for first tracer appearance in soil CO(2) efflux changed from 0 to 1.81±0.56 h (mean±SD) and the time lag for maximum tracer appearance from 2.67±0.39 to 9.63±3.32 h (mean±SD). Thus, time lags were considerably longer when physical tracer diffusion was considered. Using these time lags after accounting for physical back-diffusion, high nocturnal soil CO(2) efflux rates could be related to daytime rates of gross primary productivity (R(2)=0.84). Moreover, pronounced diurnal patterns in the δ(13)C of soil CO(2) efflux were found during the decline of the tracer over 3 weeks. Possible mechanisms include diurnal changes in the relative contributions of autotrophic and heterotrophic soil respiration as well as their respective δ(13)C values. Thus, after accounting for physical back-diffusion, we were able to quantify biological time lags in the coupling of photosynthesis and soil CO(2) efflux in grassland at the diurnal time scale.

  2. Ten Years of Robust Sources and Sinks of Atmospheric CO2 inferred from 13CO2 and pCO2 Measurements in the NOAA/CMDL Network

    NASA Astrophysics Data System (ADS)

    White, J. W.; Miller, J. B.; Tans, P. P.; Conway, T. J.

    2003-12-01

    Prediction of future climate is dependent upon the trajectory of the rising concentration of carbon dioxide, which is, in turn, dependent upon the operation of both the terrestrial and oceanic components of the carbon cycle. Because the uptake of carbon in the oceans and land operates via different mechanisms, it is useful to calculate separately the uptake (or release) by each. Atmospheric measurements of CO2 concentrations and the relative carbon-13 content offer the possibility to resolve oceanic and terrestrial carbon fluxes at relatively high spatial and temporal resolution. Even though the global totals of oceanic and terrestrial uptake derived using d13C are somewhat uncertain, we will show that both the spatial and temporal patterns are robust. Since 1990, nearly 90,000 d13CO2 measurements have been made on air collected from more than 60 globally distributed sites in the NOAA/CMDL air sampling network. When combined with measurements of CO2 made on the same air, these data allow us to calculate the oceanic and terrestrial contributions to the total surface uptake of CO2 as a function of space and time. The most prominent result of our analysis is the large and sustained uptake of carbon in the temperate Northern Hemisphere (TNH), punctuated by periods of enhanced uptake centered around 1992 and 1997. The mean size of the uptake in the TNH is ~3+/-1 GTonC/yr, roughly half the size of the total fossil fuel flux to the atmosphere. The earlier period of enhanced uptake may be associated with the eruption of Mt. Pinatubo in 1991. The reasons for the enhanced terrestrial uptake in 1997 are less clear. The next result that stands out is the large release of carbon from the tropical biosphere that occurred during the 1997-1998 El Nino. The 1998 terrestrial flux in the tropics is about 2 to 3 GTon C more than the 1991-1997 mean. Coinciding with the SST transition typical of El Nino, we also estimate that tropical oceanic fluxes rose 2 by GtonC, sustained for two

  3. 13C-methacetin breath test correlates with clinical indices of liver disease severity in patients with primary biliary cirrhosis.

    PubMed

    Kochel-Jankowska, A; Hartleb, M; Jonderko, K; Kaminska, M; Kasicka-Jonderko, A

    2013-02-01

    This prospective study intended to ascertain if cytochrome P450 dependent liver function is affected in early and late histological stages of primary biliary cirrhosis (PBC). The study included 32 female PBC patients (mean age 55.4 years, range 33-70) and 16 aged-matched healthy women (mean age 52.6 years, range 38-65). In every subject a 13(C)-methacetin breath test (13(C)-MBT) was applied, and the results were related to histological Ludwig's staging system and several indices of liver disease severity comprising the MAYO-1, MAYO-2, MELD, and Child-Pugh score. The 13(C)-MBT differentiated healthy controls from the patients with Ludwig IV and Ludwig III histopathological stages of PBC. The most significant relationships (i.e. explaining >50% of the variance) were found between measurements of the momentary breath 13(C) elimination from 6 to 18 minutes as well as the 15-min or 30-min cumulative elimination and the MAYO-1 or MAYO-2 scores. The breath test poorly correlated with histopathological features of PBC, however, it accurately discriminated cirrhotic from non-cirrhotic patients (momentary breath 13(C) elimination at 40 min, AUROC 0,958). In conclusion, 13(C)-MBT correlates with clinical scoring systems, especially those specifically designed for PBC (Mayo model) and accurately recognizes the disease at the stage of cirrhosis up to 40 minutes of the test duration.

  4. Interpreting the Lactulose Breath Test for the Diagnosis of Small Intestinal Bacterial Overgrowth.

    PubMed

    K Sunny, Joseph; Garcia, Cesar J; McCallum, Richard W

    2016-03-01

    Based on literature review, a positive lactulose breath test (LBT) for small intestinal bacterial overgrowth requires an initial peak value of hydrogen within 100 minutes of lactulose ingestion with a second peak before 180minutes. However, using scintigraphic monitoring of lactulose transit time, mean oral-cecal arrival time has been reported as 73minutes. The goal was to propose new criteria for analysing the LBT to overcome false positive interpretations. LBTs from our referral center were interpreted as positive after ingestion of 10g of lactulose using the following approach for hydrogen concentrations: (1) The literature guidelines: greater than 20ppm from a baseline less than 10ppm achieved within 100minutes followed by a further rise of greater than 15ppm within 180minutes. (2) The proposed criteria: greater than 20ppm from a baseline less than 10ppm within either 60 or 80minutes followed by a further rise of greater than 15ppm during the 180-minute test. A total of 153 patients with symptoms suspicious for small-bowel bacterial overgrowth underwent testing. Of all, 26.1% patients tested positive by 100minutes, 11.8% patients tested positive by 60minutes and 18.3% patients tested positive by 80minutes. The percentage of positive LBTs at 60 and 80minutes was significantly lesser than for the 100minutes criteria (P < 0.05). The first hydrogen peak increase should occur by either 60 or 80minutes to increase the specificity of LBT for small intestinal bacterial overgrowth based on the reality of lactulose cecal arrival times. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  5. Bad Breath

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Bad Breath KidsHealth > For Kids > Bad Breath A A ... visit your dentist or doctor . continue What Causes Bad Breath? Here are three common causes of bad ...

  6. Breath Tests in Respiratory and Critical Care Medicine: From Research to Practice in Current Perspectives

    PubMed Central

    Cheepsattayakorn, Attapon; Cheepsattayakorn, Ruangrong

    2013-01-01

    Today, exhaled nitric oxide has been studied the most, and most researches have now focusd on asthma. More than a thousand different volatile organic compounds have been observed in low concentrations in normal human breath. Alkanes and methylalkanes, the majority of breath volatile organic compounds, have been increasingly used by physicians as a novel method to diagnose many diseases without discomforts of invasive procedures. None of the individual exhaled volatile organic compound alone is specific for disease. Exhaled breath analysis techniques may be available to diagnose and monitor the diseases in home setting when their sensitivity and specificity are improved in the future. PMID:24151617

  7. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus

    PubMed Central

    Rezaie, Ali; Buresi, Michelle; Lembo, Anthony; Lin, Henry; McCallum, Richard; Rao, Satish; Schmulson, Max; Valdovinos, Miguel; Zakko, Salam; Pimentel, Mark

    2017-01-01

    Objectives: Breath tests (BTs) are important for the diagnosis of carbohydrate maldigestion syndromes and small intestinal bacterial overgrowth (SIBO). However, standardization is lacking regarding indications for testing, test methodology and interpretation of results. A consensus meeting of experts was convened to develop guidelines for clinicians and research. Methods: Pre-meeting survey questions encompassing five domains; indications, preparation, performance, interpretation of results, and knowledge gaps, were sent to 17 clinician-scientists, and 10 attended a live meeting. Using an evidence-based approach, 28 statements were finalized and voted on anonymously by a working group of specialists. Results: Consensus was reached on 26 statements encompassing all five domains. Consensus doses for lactulose, glucose, fructose and lactose BT were 10, 75, 25 and 25 g, respectively. Glucose and lactulose BTs remain the least invasive alternatives to diagnose SIBO. BT is useful in the diagnosis of carbohydrate maldigestion, methane-associated constipation, and evaluation of bloating/gas but not in the assessment of oro-cecal transit. A rise in hydrogen of ≥20 p.p.m. by 90 min during glucose or lactulose BT for SIBO was considered positive. Methane levels ≥10 p.p.m. was considered methane-positive. SIBO should be excluded prior to BT for carbohydrate malabsorption to avoid false positives. A rise in hydrogen of ≥20 p.p.m. from baseline during BT was considered positive for maldigestion. Conclusions: BT is a useful, inexpensive, simple and safe diagnostic test in the evaluation of common gastroenterology problems. These consensus statements should help to standardize the indications, preparation, performance and interpretation of BT in clinical practice and research. PMID:28323273

  8. Accuracy of urea breath test in Helicobacter pylori infection: meta-analysis.

    PubMed

    Ferwana, Mazen; Abdulmajeed, Imad; Alhajiahmed, Ali; Madani, Wedad; Firwana, Belal; Hasan, Rim; Altayar, Osama; Limburg, Paul J; Murad, Mohammad Hassan; Knawy, Bandar

    2015-01-28

    To quantitatively summarize and appraise the available evidence of urea breath test (UBT) use to diagnose Helicobacter pylori (H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy measures. We searched MEDLINE, EMBASE, Cochrane library and other databases for studies addressing the value of UBT in the diagnosis of H. pylori infection. We included cross-sectional studies that evaluated the diagnostic accuracy of UBT in adult patients with dyspeptic symptoms. Risk of bias was assessed using QUADAS (Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Diagnostic accuracy measures were pooled using the random-effects model. Subgroup analysis was conducted by UBT type (13C vs 14C) and by measurement technique (Infrared spectrometry vs Isotope Ratio Mass Spectrometry). Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies (61%) evaluated 13C UBT and 9 studies (39%) evaluated 14C UBT. There was significant variation in the type of reference standard tests used across studies.Pooled sensitivity was 0.96 (95%CI: 0.95-0.97) andpooled specificity was 0.93 (95%CI: 0.91-0.94). Likelihood ratio for a positive test was 12 and for a negative test was 0.05 with an area under thecurve of 0.985. Meta-analyses were associated with a significant statistical heterogeneity that remained unexplained after subgroup analysis. The included studies had a moderate risk of bias. UBT has high diagnostic accuracy for detecting H. pylori infection in patients with dyspepsia. The reliability of diagnostic meta-analytic estimates however is limited by significant heterogeneity.

  9. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus.

    PubMed

    Rezaie, Ali; Buresi, Michelle; Lembo, Anthony; Lin, Henry; McCallum, Richard; Rao, Satish; Schmulson, Max; Valdovinos, Miguel; Zakko, Salam; Pimentel, Mark

    2017-05-01

    Breath tests (BTs) are important for the diagnosis of carbohydrate maldigestion syndromes and small intestinal bacterial overgrowth (SIBO). However, standardization is lacking regarding indications for testing, test methodology and interpretation of results. A consensus meeting of experts was convened to develop guidelines for clinicians and research. Pre-meeting survey questions encompassing five domains; indications, preparation, performance, interpretation of results, and knowledge gaps, were sent to 17 clinician-scientists, and 10 attended a live meeting. Using an evidence-based approach, 28 statements were finalized and voted on anonymously by a working group of specialists. Consensus was reached on 26 statements encompassing all five domains. Consensus doses for lactulose, glucose, fructose and lactose BT were 10, 75, 25 and 25 g, respectively. Glucose and lactulose BTs remain the least invasive alternatives to diagnose SIBO. BT is useful in the diagnosis of carbohydrate maldigestion, methane-associated constipation, and evaluation of bloating/gas but not in the assessment of oro-cecal transit. A rise in hydrogen of ≥20 p.p.m. by 90 min during glucose or lactulose BT for SIBO was considered positive. Methane levels ≥10 p.p.m. was considered methane-positive. SIBO should be excluded prior to BT for carbohydrate malabsorption to avoid false positives. A rise in hydrogen of ≥20 p.p.m. from baseline during BT was considered positive for maldigestion. BT is a useful, inexpensive, simple and safe diagnostic test in the evaluation of common gastroenterology problems. These consensus statements should help to standardize the indications, preparation, performance and interpretation of BT in clinical practice and research.

  10. Early detection of cystic fibrosis lung disease: multiple‐breath washout versus raised volume tests

    PubMed Central

    Lum, Sooky; Gustafsson, Per; Ljungberg, Henrik; Hülskamp, Georg; Bush, Andrew; Carr, Siobhán B; Castle, Rosemary; Hoo, Ah‐fong; Price, John; Ranganathan, Sarath; Stroobant, John; Wade, Angie; Wallis, Colin; Wyatt, Hilary; Stocks, Janet

    2007-01-01

    Background Lung clearance index (LCI), a measure of ventilation inhomogeneity derived from the multiple‐breath inert gas washout (MBW) technique, has been shown to detect abnormal lung function more readily than spirometry in preschool children with cystic fibrosis, but whether this holds true during infancy is unknown. Objectives To compare the extent to which parameters derived from the MBW and the raised lung volume rapid thoraco–abdominal compression (RVRTC) techniques identify diminished airway function in infants with cystic fibrosis when compared with healthy controls. Methods Measurements were performed during quiet sleep, with the tidal breathing MBW technique being performed before the forced expiratory manoeuvres. Results Measurements were obtained in 39 infants with cystic fibrosis (mean (SD) age 41.4 (22.0) weeks) and 21 controls (37.0 (15.1) weeks). Infants with cystic fibrosis had a significantly higher respiratory rate (38 (10) vs 32 (5) bpm) and LCI (8.4 (1.5) vs 7.2 (0.3)), and significantly lower values for all forced expiratory flow‐volume parameters compared with controls. Girls with cystic fibrosis had significantly lower forced expiratory volume (FEV0.5 and FEF25–75 ) than boys (mean (95% CI girls–boys): –1.2 (–2.1 to −0.3) for FEV0.5 Z score; FEF25–75: –1.2 (–2.2 to −0.15)). When using both the MBW and RVRTC techniques, abnormalities were detected in 72% of the infants with cystic fibrosis, with abnormalities detected in 41% using both techniques and a further 15% by each of the two tests performed. Conclusions These findings support the view that inflammatory and/or structural changes in the airways of children with cystic fibrosis start early in life, and have important implications regarding early detection and interventions. Monitoring of early lung disease and functional status in infants and young children with cystic fibrosis may be enhanced by using both MBW and the RVRTC. PMID:17121870

  11. Positive Glucose Breath Tests in Patients with Hysterectomy, Gastrectomy, and Cholecystectomy

    PubMed Central

    Kim, Dae Bum; Paik, Chang-Nyol; Kim, Yeon Ji; Lee, Ji Min; Jun, Kyong-Hwa; Chung, Woo Chul; Lee, Kang-Moon; Yang, Jin-Mo; Choi, Myung-Gyu

    2017-01-01

    Background/Aims This study aimed to investigate the prevalence and characteristics of small intestinal bacterial overgrowth (SIBO) in patients undergoing abdominal surgeries, such as gastrectomy, cholecystectomy, and hysterectomy. Methods One hundred seventy-one patients with surgery (50 hysterectomy, 14 gastrectomy, and 107 cholecystectomy), 665 patients with functional gastrointestinal disease (FGID) and 30 healthy controls undergoing a hydrogen (H2)-methane (CH4) glucose breath test (GBT) were reviewed. Results GBT positivity (+) was significantly different among the surgical patients (43.9%), FGID patients (31.9%), and controls (13.3%) (p<0.01). With respect to the patients, 65 (38.0%), four (2.3%), and six (3.5%) surgical patients and 150 (22.6%), 30 (4.5%), and 32 (4.8%) FGID patients were in the GBT (H2)+, (CH4)+ and (mixed)+ groups, respectively (p<0.01). The gastrectomy group had a significantly increased preference in GBT+ (71.4% vs 42.0% or 41.1%, respectively) and GBT (H2)+ (64.3% vs 32.0% or 37.4%, respectively) compared with the hysterectomy or cholecystectomy groups (p<0.01). During GBT, the total H2 was significantly increased in the gastrectomy group compared with the other groups. Conclusions SIBO producing H2 is common in abdominal surgical patients. Different features for GBT+ may be a result of the types of abdominal surgery. PMID:27965476

  12. Association between symptoms of irritable bowel syndrome and methane and hydrogen on lactulose breath test.

    PubMed

    Lee, Kang Nyeong; Lee, Oh Young; Koh, Dong Hee; Sohn, Won; Lee, Sang Pyo; Jun, Dae Won; Lee, Hang Lak; Yoon, Byung Chul; Choi, Ho Soon; Hahm, Joon Soo

    2013-06-01

    Whether hydrogen and methane gas produced during lactulose breath test (LBT) are associated with symptoms of irritable bowel syndrome (IBS) is not determined. We aimed to investigate whether hydrogen and methane on LBT are associated with IBS symptoms. Sixty-eight IBS patients meeting the Rome III criteria for IBS, and 55 healthy controls, underwent LBT. The IBS subjects recorded their customary gastrointestinal symptoms on a questionnaire using visual analogue scales. LBT positivity was defined to be above 20 ppm rise of hydrogen or 10 ppm rise of methane within 90 min. Gas amounts produced during LBT were determined by calculating area under the curve of hydrogen and methane excretion. Symptom severity scores were not different between the LBT (+) IBS and LBT (-) IBS subjects and also between methane producers and non-methane producers. Gas amounts produced during LBT were not associated with IBS symptoms, except a weak correlation between total gas amounts and a few IBS symptoms such as bloating (r = 0.324, P = 0.039), flatulence (r = 0.314, P = 0.046) and abdominal pain (r = 0.364, P = 0.018) only in LBT (+) IBS. In conclusion, hydrogen and methane gas on LBT are not useful for predicting the customary symptoms and subtypes of IBS.

  13. Association between Symptoms of Irritable Bowel Syndrome and Methane and Hydrogen on Lactulose Breath Test

    PubMed Central

    Lee, Kang Nyeong; Koh, Dong Hee; Sohn, Won; Lee, Sang Pyo; Jun, Dae Won; Lee, Hang Lak; Yoon, Byung Chul; Choi, Ho Soon; Hahm, Joon Soo

    2013-01-01

    Whether hydrogen and methane gas produced during lactulose breath test (LBT) are associated with symptoms of irritable bowel syndrome (IBS) is not determined. We aimed to investigate whether hydrogen and methane on LBT are associated with IBS symptoms. Sixty-eight IBS patients meeting the Rome III criteria for IBS, and 55 healthy controls, underwent LBT. The IBS subjects recorded their customary gastrointestinal symptoms on a questionnaire using visual analogue scales. LBT positivity was defined to be above 20 ppm rise of hydrogen or 10 ppm rise of methane within 90 min. Gas amounts produced during LBT were determined by calculating area under the curve of hydrogen and methane excretion. Symptom severity scores were not different between the LBT (+) IBS and LBT (-) IBS subjects and also between methane producers and non-methane producers. Gas amounts produced during LBT were not associated with IBS symptoms, except a weak correlation between total gas amounts and a few IBS symptoms such as bloating (r = 0.324, P = 0.039), flatulence (r = 0.314, P = 0.046) and abdominal pain (r = 0.364, P = 0.018) only in LBT (+) IBS. In conclusion, hydrogen and methane gas on LBT are not useful for predicting the customary symptoms and subtypes of IBS. PMID:23772156

  14. Lactulose Hydrogen Breath Test Result Is Associated with Age and Gender

    PubMed Central

    Newberry, Carolyn; Tierney, Ann; Pickett-Blakely, Octavia

    2016-01-01

    Small intestinal bacterial overgrowth (SIBO) is associated with chronic gastrointestinal diseases and structural/functional abnormalities of the gastrointestinal tract. SIBO's association with clinical characteristics is unclear. This study investigates the association between clinical factors and SIBO according to lactulose hydrogen breath test (LHBT) result. Methods. A cross-sectional study in a university-based gastroenterology practice was performed. Data was abstracted from the medical records of subjects undergoing LHBT from 6/1/2009 to 6/1/2013. Logistic regression analysis was performed to determine the association between predictor variables: age, sex, body mass index (BMI), and positive LHBT, the outcome of interest. Results. LHBT was performed in 791 subjects. Fifty-four percent had a positive LHBT. There was no statistically significant difference between the LHBT results according to age or BMI. In females, the likelihood of a positive LHBT increased with age (OR 1.02; 95% CI: 1.01–1.03). In males, the likelihood of a positive LHBT result decreased with age (OR 0.98; 95% CI: 0.97–1.00). Conclusion. There was an association between age, with respect to sex, and a positive LHBT. With increased age in females, the odds of a positive LHBT increased, while, in men, the odds of a positive LHBT decreased with age. PMID:27073800

  15. Rapid orocecal transit time in obese children measured by hydrogen breath test.

    PubMed

    Rerksuppaphol, Sanguansak; Rerksuppaphol, Lakkana

    2012-12-01

    Gastrointestinal motility may correlate with an unusual nutritional status, such as obesity. The orocecal transit time (OCTT) is one parameter of GI motility. The primary objective of the present study was to compare OCTT in obese and non-obese children; secondary objectives were to assess the correlation between OCTT and body mass index (BMI) or appetite score. A cross-sectional study was conducted in 44 children. Twenty-one obese and 18 non-obese children were included in the final analysis. Demographic data and anthropometric parameters were collected. The breath hydrogen test (BHT) using lactulose was performed to determine OCTT. Appetite score using visual analog scale was measured at the beginning and end of the present study. The difference between these scores was attributed as an increase of appetite. Student t-test and Chi-square test were employed to compare the differences between groups. Pearson's correlation was used to measure the correlation between parameters. Mean OCTT in obese children was significantly faster than in non-obese children (70.0 versus 81.1 min, respectively; p-value = 0.005). The increases of appetite score during study were not significantly different between obese and non-obese children (4.3 vs. 2.9; p-value = 0.19). OCTT was significantly associated with BMI in the inverse manner (r = -0.51; p-value = 0.001), but was not significantly correlated with the appetite score (r = -0.24; p-value = 0.15). OCTT in obese children was faster than in non-obese children. OCTT was moderately inversely correlated with the BMI, and had a trend to negative correlation with the appetite score, though without reaching a significant value.

  16. Autotrophic and heterotrophic soil respiration determined with trenching, soil CO2 fluxes and 13CO2/12CO2 concentration gradients in a boreal forest ecosystem

    NASA Astrophysics Data System (ADS)

    Pumpanen, Jukka; Shurpali, Narasinha; Kulmala, Liisa; Kolari, Pasi; Heinonsalo, Jussi

    2017-04-01

    Soil CO2 efflux forms a substantial part of the ecosystem carbon balance, and it can contribute more than half of the annual ecosystem respiration. Recently assimilated carbon which has been fixed in photosynthesis during the previous days plays an important role in soil CO2 efflux, and its contribution is seasonally variable. Moreover, the recently assimilated C has been shown to stimulate the decomposition of recalcitrant C in soil and increase the mineralization of nitrogen, the most important macronutrient limiting gross primary productivity (GPP) in boreal ecosystems. Podzolic soils, typical in boreal zone, have distinctive layers with different biological and chemical properties. The biological activity in different soil layers has large seasonal variation due to vertical gradient in temperature, soil organic matter and root biomass. Thus, the source of CO2 and its components have a vertical gradient which is seasonally variable. The contribution of recently assimilated C and its seasonal as well as spatial variation in soil are difficult to assess without disturbing the system. The most common method of partitioning soil respiration into its components is trenching which entails the roots being cut or girdling where the flow of carbohydrates from the canopy to roots has been isolated by cutting of the phloem. Other methods for determining the contribution of autotrophic (Ra) and heterotrophic (Rh) respiration components in soil CO2 efflux are pulse labelling with 13CO2 or 14CO2 or the natural abundance of 13C and/or 14C isotopes. Also differences in seasonal and short-term temperature response of soil respiration have been used to separate Ra and Rh. We compared the seasonal variation in Ra and Rh using the trenching method and differences between seasonal and short-term temperature responses of soil respiration. I addition, we estimated the vertical variation in soil biological activity using soil CO2 concentration and the natural abundance of 13C and 12C

  17. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow the...

  18. 49 CFR 40.243 - What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow the...

  19. Assessment of antibacterial effect of garlic in patients infected with Helicobacter pylori using urease breath test

    PubMed Central

    Zardast, Mahmoud; Namakin, Kokab; Esmaelian Kaho, Jamil; Hashemi, Sarira Sadat

    2016-01-01

    Objective: Helicobacter pylori (H. pylori) is the most common pathogenic bacteria in the stomach. The aim of the current study was to explore the effect of oral garlic administration on bacterial urease activity inside the stomach and its contribution to the treatment of H. pylori infection. Materials and Methods: In this clinical trial, 15 patients were studied quantitatively with Urease Breath Test (UBT). The patients with gastrointestinal symptoms and a positive serum H. pylori IgG were enrolled. UBT was performed for each patient in three sessions as follows: at the beginning of the study, an initial UBT was performed based on which, the positive cases entered the study and the negative ones were excluded. Second UBT was done three days later in patients who were not receiving any treatment and were considered as the control, whereas the third UBT was performed three days after prescribing two medium-sized cloves of garlic (3 g) with their meal, twice a day (at noon and in the evening). The collected data were analyzed using ANOVA and Bonferroni tests and the significance level was set at p<0.05. Results: the mean UBT significantly differed before and after treatment with garlic cloves, being significantly lower after garlic consumption. No meaningful difference was observed in the mean UBT without garlic consumption between the first and second steps. Conclusion: Raw garlic has anti-bacterial effects against H. pylori residing in the stomach and may be prescribed along with routine drugs for the treatment of gastric H. pylori infection. PMID:27761418

  20. Exhaled breath condensate pH decreases following oral glucose tolerance test.

    PubMed

    Bikov, Andras; Pako, Judit; Montvai, David; Kovacs, Dorottya; Koller, Zsofia; Losonczy, Gyorgy; Horvath, Ildiko

    2015-12-15

    Exhaled breath condensate (EBC) pH is a widely measured non-invasive marker of airway acidity. However, some methodological aspects have not been thoroughly investigated. The aim of the study was to determine the effect of oral glucose tolerance test (OGTT) on EBC pH in attempt to better standardize its measurement. Seventeen healthy subjects (24  ±  2 years, 6 men, 11 women) participated in the study. EBC collection and capillary blood glucose measurements were performed before as well as 0, 30, 60 and 120 min after a standardized OGTT test. The rate of respiratory droplet dilution and pH were evaluated in EBC. Blood glucose significantly increased at 30 min and maintained elevation after 60 and 120 min following OGTT. Compared to baseline (7.99  ±  0.25) EBC pH significantly decreased immediately after OGTT (7.41  ±  0.47); this drop sustained over 30 (7.44  ±  0.72) and 60 min (7.62  ±  0.44) without a significant difference at 120 min (7.78  ±  0.26). No change was observed in the rate of respiratory droplet dilution. There was no relationship between blood glucose and EBC pH values. Sugar intake may significantly decrease EBC pH. This effect needs to be considered when performing EBC pH studies. Further experiments are also warranted to investigate the effect of diet on other exhaled biomarkers.

  1. Domestic Preparedness Program: Phase 2 Sarin (GB) and Distilled Sulfur Mustard (HD) Vapor Challenge Testing of Commercial Self-Contained Breathing Apparatus Facepieces

    DTIC Science & Technology

    2005-03-01

    GB Mustard HD Self-Contained Breathing Apparatus Sarin Chemical Agent Breakthrough SCBA Agent Challenge Testing ...emergency escape breathing apparatus. 3. CHEMICAL AGENT TESTING 3.1 Chemical Agent Testing Equipment. 3.1.1 Vapor Generator. The GB and HD vapors were... agent seeped inside the other two within 4 min. For all three tests , the North Model 821 resisted HD for 60 min and GB for 25, 28, and 32 min.

  2. Utility of wireless motility capsule and lactulose breath testing in the evaluation of patients with chronic functional bloating

    PubMed Central

    Triadafilopoulos, George

    2016-01-01

    Background The precise aetiology of chronic bloating remains poorly understood and underlying gastroparesis, small bowel bacterial overgrowth and colonic inertia may, individually or collectively, play a role. Aims In this retrospective cohort analysis of symptomatic patients with chronic persistent bloating, we determined the clinical utility of wireless motility capsule and lactulose breath test in further defining the underlying aetiology for functional bloating. Methods Consecutive patients with chronic bloating underwent clinical assessment, wireless motility capsule testing and lactulose breath testing using standard protocols. Results 52 patients qualified for inclusion in this analysis, fulfilling Rome III criteria for functional bloating. Most patients (54%) had an abnormal wireless motility capsule study; of those, 11.5% had evidence of gastroparesis, 7.7% had small bowel transit delay, 15.8% had colonic inertia, 3.8% had delayed gastric and small bowel transit, 5.6% had combined gastric and colonic transit delay, 3.8% had delayed small bowel and colonic transit, and 5.6% had delayed gastric, small bowel and colon transit times. Using clinical questionnaires the median scores for bloating, constipation and eructation were not significantly different. Neither constipation nor eructation was specific to gastroparesis or colonic inertia but bloating was numerically more prevalent and severe in patients with delayed small bowel transit. 40% of patients had positive lactulose breath test but had no distinguishing clinical characteristics. Conclusions Chronic functional bloating may reflect underlying gastroparesis, small intestinal bacterial overgrowth or colonic inertia. Wireless motility capsule and lactulose breath test are useful in the assessment of patients with bloating and should be considered during evaluation. PMID:27648298

  3. Sensitivity and specificity of an abbreviated 13C-mixed triglyceride breath test for measurement of pancreatic exocrine function

    PubMed Central

    Meier, Viola; Wolfram, Kristina U; Rosien, Ulrich; Layer, Peter

    2014-01-01

    Background A modified 13C-mixed triglyceride breath test (13C -MTGT) detects moderate pancreatic exocrine insufficiency noninvasively and reliably, but it requires prolonged breath sampling (6 hours (hr)). Objective We aimed to investigate whether 13C -MTGT can be abbreviated, to optimize clinical usability. Methods We analyzed the 13C-MTGT of 200 consecutive patients, retrospectively. Cumulative 1–5 hr 13C-exhalation values were compared with the standard parameter (6-hr cumulative 13C-exhalation). We determined the sensitivity and specificity of shortened breath sampling periods, by comparison with the normal values from 10 healthy volunteers, whom also underwent a secretin test to quantitate pancreatic secretion. Moreover, we evaluated the influence of gastric emptying (GE), using a 13C-octanoic acid breath test in a subset (N = 117). Results The 1–5 hr cumulative 13C-exhalation tests correlated highly and significantly with the standard parameter (p < 0.0001). Sensitivity for detection of impaired lipolysis was high (≥77%), but the specificity was low (≥38%) for the early measurements. Both parameters were high after 4 hrs (88% and 94%, respectively) and 5 hrs (98% and 91%, respectively). Multivariate linear correlation analysis confirmed that GE strongly influenced early postprandial 13C-exhalation during the 13C-MTGT. Conclusion Shortening of the 13C -MTGT from 6 to 4 hrs of duration was associated with similar diagnostic accuracy, yet increased clinical usability. The influence of GE on early postprandial results of the 13C-MTGT precluded further abbreviation of the test. PMID:25083286

  4. Evaluation of the hydrogen breath test in man: definition and elimination of the early hydrogen peak.

    PubMed

    Mastropaolo, G; Rees, W D

    1987-06-01

    After ingestion of a non-absorbable carbohydrate breath hydrogen excretion increases early at about 10 minutes, and again later when the ingested carbohydrate enters the caecum. The late rise has been used as a marker of mouth to caecum transit time, but the source of the early rise has not been satisfactorily explained. We studied in 60 healthy volunteers the source and frequency of the early rise in breath hydrogen after ingestion of a non-absorbable carbohydrate. After ingestion of either lactulose solution (10 g in 150 ml water), lentil soup (46 g carbohydrate) or solid meal containing baked beans (15 g carbohydrate), breath hydrogen was significantly raised above basal concentrations within 10 minutes (81 +/- 27, 395 +/- 138 and 110 +/- 52% above basal respectively). A significant rise in breath hydrogen (75 +/- 21%) occurred 10 minutes after sham lactulose feeding (lactulose applied to oral cavity but not swallowed), but no early peak occurred after sham saccharin feeding (non-fermentable carbohydrate), intragastric or intraduodenal administration of lactulose. Ten of the 12 subjects given lactulose sham feeding were restudied after oral hygiene with chlorhexidine mouthwash. In these the early hydrogen peak was abolished. Oral hygiene also reduced the occurrence and magnitude of the early hydrogen rise after lactulose ingestion. These findings indicate that the early rise in breath hydrogen observed after ingestion of lactulose is produced by interaction with oral bacteria.

  5. Validation of a simplified carbon-14-urea breath test for routine use for detecting Helicobacter pylori noninvasively

    SciTech Connect

    Henze, E.; Malfertheiner, P.; Clausen, M.; Burkhardt, H.; Adam, W.E. )

    1990-12-01

    A carbon-14 ({sup 14}C) urea breath test for detecting Helicobacter pylori with multiple breath sampling was developed. Carbon-14-urea (110 kBq) administered orally to 18 normal subjects and to 82 patients with Helicobacter infection. The exhaled {sup 14}C-labeled CO{sub 2} was trapped at 10-min intervals for 90 min. The total {sup 14}C activity exhaled over 90 min was integrated and expressed in %activity of the total dose given. In normals, a mean of 0.59% +/- 0.24% was measured, resulting in an upper limit of normal of 1.07%. In 82 patients, a sensitivity of 90.2%, a specificity of 83.8%, and a positive predictive value of 90.2% was found. The single probes at intervals of 40-60 min correlated best with the integrated result, with r ranging from 0.986 to 0.990. The test's diagnostic accuracy did not change at all when reevaluated with the 40-, 50-, or 60-min sample data alone. Thus, the {sup 14}C-urea breath test can be applied routinely as a noninvasive, low-cost and one-sample test with high diagnostic accuracy in detecting Helicobacter pylori colonization.

  6. [BREATH TEST WITH LOCALLY PRODUCED 13С-UREA (TBILISI, GEORGIA) IN DIAGNOSTICS OF HELICOBACTER PYLORI INFECTION].

    PubMed

    Girdaladze, A; Mosidze, B; Elisabedashvili, G; Kordzaia, D

    2016-04-01

    Comparative assessment of results of detection of Helicobacter pylori (Hp) infection by breath tests with standard and locally produced 13С urea was done in 213 patients with gastric and duodenal pathology, including those who already were undergone the surgery. Invasive endoscopic biopsy test including rapid urease test (RUT), smear cytology and histology were also performed (tissue samples were obtained after endoscopy or surgery). RUT was carried out with the help of URE-HP test kit. Serological test for Hp antibodies was performed by IFA using kit ELISA. 13С urea breath test (UBT) was conducted for the determination of 13/12CO2 in breath samples by using of infrared spectroscope. In I group (125 patients) UBT was performed with standard 13С urea, in II group (88 patients) with locally produced 13С urea. Based on 5 different methods of Hp infection testing Hp positivity in 172 (80,8%) and Hp negativity in 41 (19,2%) patients were revealed. 13С-UBT showed the highest diagnostic value (accuracy-97,5%, sensibility-97,0%, specificity-100%) in Hp infection diagnosis. The (accuracy, sensibility and specificity of breath test with locally issued 13С urea (98,7%, 98,5% and 100% respectively) are the same as those for BT with standard 13С urea (96,7%, 96,2% and 100% respectively). These parameters are also highly credible in control of treatment efficiency (96,7%, 90,0% and 100% respectively). The correlation of index DOB‰ of breath test with results of RUT was revealed In Hp positive patients. This can serve as a marker of Hp infection rate. Preliminarily, in pre-clinical experimental study, harmless of locally issued 13С-urea from point of view of acute/sub-acute toxicity and allergy development was confirmed. The advantages (noninvasiveness, simplicity, rapidity, safety) and high diagnostic value of UBT (with both standard as well as locally produced 13С-urea) provide the opportunity to offer 13С-UBT as screening method of Hp infection diagnosis. It also

  7. Evaluation of stool antigen test for Helicobacter pylori infection in asymptomatic children from a developing country using 13C-urea breath test as a standard.

    PubMed

    Shaikh, Saijuddin; Khaled, M A; Islam, Aminul; Kurpad, A V; Mahalanabis, Dilip

    2005-05-01

    Prevalence of asymptomatic Helicobacter pylori infection is very high in infants and children in developing countries. C urea breath test (UBT) is a reliable non-invasive diagnostic test for H. pylori infection in children that avoids invasive endoscopy. We compared a newly introduced H. pylori stool antigen test (with a high sensitivity and specificity in symptomatic children) with UBT in asymptomatic children mostly 1-5 years old, from a population with a high prevalence of infection. Eighty six asymptomatic children (42 boys and 44 girls) were tested for H. pylori infection using the UBT and a stool antigen test (HpSA) based on a sandwich enzyme immunoassay for antigen detection. Forty five of the eighty-six (52.3%) children tested positive for H. pylori using the breath test. In 34 of these forty-five children, H. pylori antigen was detected in stool (sensitivity = 75.6%, 95% CI = 63 to 88%). Of the 50 of 86 (58%) children positive by HpSA test, 34 were positive for breath test. Of the 41 children with negative UBT test 25 were negative for stool antigen test (specificity = 61%, 95% CI = 46 to 76%). The sensitivity and specificity of the new stool antigen test are lower in asymptomatic children with high H. pylori prevalence rate compared to those reported for children with gastrointestinal symptoms. Its usefulness is limited for diagnosis in an asymptomatic child with H. pylori infection.

  8. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    The development of a breathing metabolic simulator (BMS) is reported. This BMS simulates all of the breathing and metabolic parameters required for complete evaluation and test of life support and resuscitation equipment. It is also useful for calibrating and validating mechanical and gaseous pulmonary function test procedures. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges simulating conditions from sleep to hard work with respiratory exchange ratios covering the range from hypoventilation. In addition, all of these parameters are remotely controllable to facilitate use of the device in hostile or remote environments. The exhaled breath is also maintained at body temperature and a high humidity. The simulation is accurate to the extent of having a variable functional residual capacity independent of other parameters.

  9. Diagnostic accuracy of the (14)C-urea breath test in Helicobacter pylori infections: a meta-analysis.

    PubMed

    Zhou, Qiaohui; Li, Ling; Ai, Yaowei; Pan, Zhihong; Guo, Mingwen; Han, Jingbo

    2017-01-01

    To summarize and appraise the available literature regarding the use of the (14)C-urea breath test in the diagnosis of Helicobacter pylori infections in adult patients with dyspepsia and to calculate pooled diagnostic accuracy measures. We systematically searched the PubMed, EMBASE, Cochrane Library, Chinese Journals Full-text (CNKI) and CBMDisc databases to identify published data regarding the sensitivity, specificity, and other measures of diagnostic accuracy of the (14)C-urea breath test in the diagnosis of Helicobacter pylori infections in adult patients with dyspeptic symptoms. Risk of bias was assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Statistical analyses were performed using Meta-Disc 1.4 software and STATA. Eighteen studies met the inclusion criteria. Pooled results indicated that the (14)C-urea breath test showed a diagnostic sensitivity of 0.96 (95% CI 0.95 to 0.96) and specificity of 0.93 (95% CI 0.91 to 0.94). The positive like ratio (PLR) was 12.27 (95% CI 8.17 to 18.44), the negative like ratio (NLR) was 0.05 (95% CI 0.04 to 0.07), and the area under the curve was 0.985. The DOR was 294.95 (95% CI 178.37 to 487.70). The (14)C-urea breath test showed sufficient sensitivity and specificity for diagnosing Helicobacter pylori infection, but unexplained heterogeneity after meta-regression and several subgroup analyses remained. The UBT has high accuracy for diagnosing H. pylori infections in adult patients with dyspepsia. However, the reliability of these diagnostic meta-analytic estimates is limited by significant heterogeneity due to unknown factors.

  10. U.S. Navy Unmanned Test Methods and Performance Limits for Underwater Breathing Apparatus

    DTIC Science & Technology

    2015-06-01

    gas mixture HP High pressure ID Inside diameter in. Inches J/L Joules per liter (unit of breathing effort, equivalent to 1 kPa) kg⋅m/L...be given. 3-1.2 Data Acquisition The digital sampling of pressure and volume data must occur at a rate high enough to faithfully resolve...filling the diver’s lungs. If breathing bags are placed high on the chest or back of an upright diver, a pressure imbalance will exist with the

  11. Drunken driving and breath alcohol test at the scene of violence in Japan.

    PubMed

    Marumo, Y; Kishi, T; Seta, S

    1992-04-01

    Road Traffic Law prescribes that no person shall drive any vehicle under the influence of intoxicating liquor. Actually, determination of "influence of alcohol" is based on the standard set by the Cabinet Order that alcohol level exceeds 0.5 mg/ml of blood or 0.25 mg/l of expiration. In 1988, number of traffic accidents by drunken driving is 4,808 cases. Among the accidents by drunken driving the rate of fatal causes is 12%. During about last ten years, both of accidents and fatal cases by drunken driving have been decreasing in number, on the other hand, charged or cited number of violation involved "driving under the influence of alcohol" has been increasing. This fact indicates that the concept of seriousness of driving after heavy drinking has been diffused over Japanese nation, but there is still a tendency among drivers to consider the effect of alcohol on driving operation to be negligible when light drinking. In a sobriety checkpoint, alcohol field test are carried out on breath to screen out impaired driver. The most common device used in Japan is an alcohol detector tube, in which cerite particles coated with chromate are packed. The scale on the detector tube is marked to show a value that is lower by 20% than the actual value concerning its inaccuracy. In our study on accuracy of the alcohol detector tube using samples containing approximately 0.25 mg/l of alcohol, which is legal critical level of alcohol impairment, coefficients of variation were 1.50 to 5.45% and deviations from the analytical results by gas chromatography were 18.2 to 19.5%.

  12. Helicobacter pylori infection in type 1 diabetes children and adolescents using 13C urea breath test.

    PubMed

    Chobot, Agata; Bak-Drabik, Katarzyna; Skała-Zamorowska, Eliza; Krzywicka, Agnieszka; Kwiecień, Jarosław; Polańska, Joanna

    2014-01-01

    There is a 10-30% prevalence of HP infection in the general pediatric population in Poland. This study aimed to determine its prevalence in T1DM children in Upper Silesia, Poland and estimate its influence on metabolic control of patients. We studied 149 (82 female) children with T1DM (duration > 12 months, mean HbA1c) and 298 (164 female) age-matched controls. In all cases height and weight z-scores and Cole's index were assessed. In T1DM patients additionally glycated hemoglobin A1c and T1DM duration were analyzed. Presence of HP infection was determined using 13C-isotope-labeled urea breath test (UBT) (fasting and 30 min after ingestion 75 mg of 13C urea). HP infection was present in 17 (11.4%) T1DM patients and in 49 (16.4%) controls (p > 0.05). T1DM patients presented higher values of anthropometric parameters than healthy controls (weight SDS 0.25[-0.46 divided by 0.84] vs. -0.25 [-1.06 divided by 0.26], height SDS 0.09 [-0.60 divided by 0.69] vs. -0.31[-1.17 divided by 0.48] and Cole's index 103% [93 divided by 111%] vs. 97% [86 divided by 106%]; for all p < 0001). Within both groups--T1DM children and controls--no differences regarding sex, age and any of the anthropometric parameters were determined. T1DM duration and HbA1c showed no relation to prevalence of HP infection. Prevalence of HP infection in pediatric T1DM patients is similar to that of healthy peers and shows no relation to glycemic control.

  13. Dual therapy for third-line Helicobacter pylori eradication and urea breath test prediction.

    PubMed

    Nishizawa, Toshihiro; Suzuki, Hidekazu; Maekawa, Takama; Harada, Naohiko; Toyokawa, Tatsuya; Kuwai, Toshio; Ohara, Masanori; Suzuki, Takahiro; Kawanishi, Masahiro; Noguchi, Kenji; Yoshio, Toshiyuki; Katsushima, Shinji; Tsuruta, Hideo; Masuda, Eiji; Tanaka, Munehiro; Katayama, Shunsuke; Kawamura, Norio; Nishizawa, Yuko; Hibi, Toshifumi; Takahashi, Masahiko

    2012-06-07

    We evaluated the efficacy and tolerability of a dual therapy with rabeprazole and amoxicillin (AMX) as an empiric third-line rescue therapy. In patients with failure of first-line treatment with a proton pump inhibitor (PPI)-AMX-clarithromycin regimen and second-line treatment with the PPI-AMX-metronidazole regimen, a third-line eradication regimen with rabeprazole (10 mg q.i.d.) and AMX (500 mg q.i.d.) was prescribed for 2 wk. Eradication was confirmed by the results of the ¹³C-urea breath test (UBT) at 12 wk after the therapy. A total of 46 patients were included; however, two were lost to follow-up. The eradication rates as determined by per-protocol and intention-to-treat analyses were 65.9% and 63.0%, respectively. The pretreatment UBT results in the subjects showing eradication failure; those patients showing successful eradication comprised 32.9 ± 28.8 permil and 14.8 ± 12.8 permil, respectively. The pretreatment UBT results in the subjects with eradication failure were significantly higher than those in the patients with successful eradication (P = 0.019). A low pretreatment UBT result (≤ 28.5 permil) predicted the success of the eradication therapy with a positive predictive value of 81.3% and a sensitivity of 89.7%. Adverse effects were reported in 18.2% of the patients, mainly diarrhea and stomatitis. Dual therapy with rabeprazole and AMX appears to serve as a potential empirical third-line strategy for patients with low values on pretreatment UBT.

  14. Cultural values and random breath tests as moderators of the social influence on drunk driving in 15 countries.

    PubMed

    Cestac, Julien; Kraïem, Sami; Assailly, Jean-Pascal

    2016-02-01

    The social influence on drunk driving has been previously observed in several countries. It is noteworthy, however, that the prevalence of alcohol in road fatalities is not the same in all countries. The present study aimed to explore whether cultural values and the number of roadside breath tests moderate the link between the perceived drunk driving of one's peers and self-reported behavior. Based on the European survey SARTRE 4, the responses of 10,023 car drivers from 15 countries were analyzed. Two cultural values, "tradition" and "conformism," were identified as possibly being linked to social influence. Country scores for these values were taken from the European Social Survey. The number of random roadside breath tests per inhabitant was used as an indicator of drunk-driving enforcement in each country. A hierarchical multilevel modeling analysis confirmed the link between friends' drunk driving and one's own drunk driving in all countries, but the strength of the link was much stronger in some countries (e.g., Italy, Cyprus, and Israel) than in others (e.g., Finland, Estonia, and Sweden). Both the measured value of "tradition" and the number of alcohol breath tests were found to moderate the link between friends' and one's own drunk driving. European stakeholders should take into account cultural specificities of target countries when designing campaigns against drunk driving. Copyright © 2015. Published by Elsevier Ltd.

  15. Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea

    PubMed Central

    Yang, Jian-Feng; Fox, Mark; Chu, Hua; Zheng, Xia; Long, Yan-Qin; Pohl, Daniel; Fried, Michael; Dai, Ning

    2015-01-01

    AIM: To validate 4-sample lactose hydrogen breath testing (4SLHBT) compared to standard 13-sample LHBT in the clinical setting. METHODS: Irritable bowel syndrome patients with diarrhea (IBS-D) and healthy volunteers (HVs) were enrolled and received a 10 g, 20 g, or 40 g dose lactose hydrogen breath test (LHBT) in a randomized, double-blinded, controlled trial. The lactase gene promoter region was sequenced. Breath samples and symptoms were acquired at baseline and every 15 min for 3 h (13 measurements). The detection rates of lactose malabsorption (LM) and lactose intolerance (LI) for a 4SLHBT that acquired four measurements at 0, 90, 120, and 180 min from the same data set were compared with the results of standard LHBT. RESULTS: Sixty IBS-D patients and 60 HVs were studied. The genotype in all participants was C/C-13910. LM and LI detection rates increased with lactose dose from 10 g, 20 g to 40 g in both groups (P < 0.001). 4SLHBT showed excellent diagnostic concordance with standard LHBT (97%-100%, Kappa​​ 0.815-0.942) with high sensitivity (90%-100%) and specificity (100%) at all three lactose doses in both groups. CONCLUSION: Reducing the number of measurements from 13 to 4 samples did not significantly impact on the accuracy of LHBT in health and IBS-D. 4SLHBT is a valid test for assessment of LM and LI in clinical practice. PMID:26140004

  16. A better state-of-mind: deep breathing reduces state anxiety and enhances test performance through regulating test cognitions in children.

    PubMed

    Khng, Kiat Hui

    2016-09-26

    A pre-test/post-test, intervention-versus-control experimental design was used to examine the effects, mechanisms and moderators of deep breathing on state anxiety and test performance in 122 Primary 5 students. Taking deep breaths before a timed math test significantly reduced self-reported feelings of anxiety and improved test performance. There was a statistical trend towards greater effectiveness in reducing state anxiety for boys compared to girls, and in enhancing test performance for students with higher autonomic reactivity in test-like situations. The latter moderation was significant when comparing high-versus-low autonomic reactivity groups. Mediation analyses suggest that deep breathing reduces state anxiety in test-like situations, creating a better state-of-mind by enhancing the regulation of adaptive-maladaptive thoughts during the test, allowing for better performance. The quick and simple technique can be easily learnt and effectively applied by most children to immediately alleviate some of the adverse effects of test anxiety on psychological well-being and academic performance.

  17. In Vitro Tests for Aerosol Deposition. IV: Simulating Variations in Human Breath Profiles for Realistic DPI Testing.

    PubMed

    Delvadia, Renishkumar R; Wei, Xiangyin; Longest, P Worth; Venitz, Jurgen; Byron, Peter R

    2016-04-01

    The amount of drug aerosol from an inhaler that can pass through an in vitro model of the mouth and throat (MT) during a realistic breath or inhalation flow rate vs. time profile (IP) is designated the total lung dose in vitro, or TLDin vitro. This article describes a clinical study that enabled us to recommend a general method of selecting IPs for use with powder inhalers of known airflow resistance (R) provided subjects followed written instructions either alone or in combination with formal training. In a drug-free clinical trial, inhaler-naïve, nonsmoking healthy adult human volunteers were screened for normal pulmonary function. IPs were collected from each volunteer inhaling through different air flow resistances after different levels of training. IPs were analyzed to determine the distribution of inhalation variables across the population and their dependence on training and airflow resistance. Equations for IP simulation are presented that describe the data including confidence limits at each resistance and training condition. Realistic IPs at upper (90%), median (50%), and lower (10%) confidence limits were functions of R and training. Peak inspiratory flow rates (PIFR) were inversely proportional to R so that if R was assigned, values for PIFR could be calculated. The time of PIFR, TPIFR, and the total inhaled volume (V) were unrelated to R, but dependent on training. Once R was assigned for a powder inhaler to be tested, a range of simulated IPs could be generated for the different training scenarios. Values for flow rate acceleration and depth of inspiration could also be varied within the population limits of TPIFR and V. The use of simulated IPs, in concert with realistic in vitro testing, should improve the DPI design process and the confidence with which clinical testing may be initiated for a chosen device.

  18. In Vitro Tests for Aerosol Deposition. IV: Simulating Variations in Human Breath Profiles for Realistic DPI Testing

    PubMed Central

    Delvadia, Renishkumar R.; Wei, Xiangyin; Longest, P. Worth; Venitz, Jurgen

    2016-01-01

    Abstract Background: The amount of drug aerosol from an inhaler that can pass through an in vitro model of the mouth and throat (MT) during a realistic breath or inhalation flow rate vs. time profile (IP) is designated the total lung dose in vitro, or TLDin vitro. This article describes a clinical study that enabled us to recommend a general method of selecting IPs for use with powder inhalers of known airflow resistance (R) provided subjects followed written instructions either alone or in combination with formal training. Methods: In a drug-free clinical trial, inhaler-naïve, nonsmoking healthy adult human volunteers were screened for normal pulmonary function. IPs were collected from each volunteer inhaling through different air flow resistances after different levels of training. IPs were analyzed to determine the distribution of inhalation variables across the population and their dependence on training and airflow resistance. Results: Equations for IP simulation are presented that describe the data including confidence limits at each resistance and training condition. Realistic IPs at upper (90%), median (50%), and lower (10%) confidence limits were functions of R and training. Peak inspiratory flow rates (PIFR) were inversely proportional to R so that if R was assigned, values for PIFR could be calculated. The time of PIFR, TPIFR, and the total inhaled volume (V) were unrelated to R, but dependent on training. Once R was assigned for a powder inhaler to be tested, a range of simulated IPs could be generated for the different training scenarios. Values for flow rate acceleration and depth of inspiration could also be varied within the population limits of TPIFR and V. Conclusions: The use of simulated IPs, in concert with realistic in vitro testing, should improve the DPI design process and the confidence with which clinical testing may be initiated for a chosen device. PMID:26447531

  19. Variables that Impact on the Results of Breath-Alcohol Tests

    ERIC Educational Resources Information Center

    Labianca, Dominick A.

    2004-01-01

    In a 2003 issue of the "Journal of Chemical Education," Kniesel and Bellamy describe a timely and pedagogically effective experiment involving breath-alcohol analysis using an FTIR (Fourier Transform Infrared Spectroscopy) spectrometer. The present article clarifies some of the information presented in the 2003 article.

  20. Variables that Impact on the Results of Breath-Alcohol Tests

    ERIC Educational Resources Information Center

    Labianca, Dominick A.

    2004-01-01

    In a 2003 issue of the "Journal of Chemical Education," Kniesel and Bellamy describe a timely and pedagogically effective experiment involving breath-alcohol analysis using an FTIR (Fourier Transform Infrared Spectroscopy) spectrometer. The present article clarifies some of the information presented in the 2003 article.

  1. Methane and hydrogen positivity on breath test is associated with greater body mass index and body fat.

    PubMed

    Mathur, R; Amichai, M; Chua, K S; Mirocha, J; Barlow, G M; Pimentel, M

    2013-04-01

    Colonization of the gastrointestinal tract with methanogenic archaea (methanogens) significantly affects host metabolism and weight gain in animal models, and breath methane is associated with a greater body mass index (BMI) among obese human subjects. The objective of the study was to characterize the relationship between methane and hydrogen on breath test (as a surrogate for colonization with the hydrogen requiring methanogen, Methanobrevibacter smithii), body weight, and percent body fat in a general population cohort. This was a prospective study (n = 792) of consecutive subjects presenting for breath testing. The study was conducted at a tertiary care center. BMI and percent body fat were measured. Subjects were classified into 4 groups based on breath testing: normal (N) (methane <3 ppm and hydrogen <20 ppm at or before 90 minutes); hydrogen positive only (H+) [methane <3 ppm and hydrogen ≥20 ppm); methane positive only (M+) (methane ≥3 ppm and hydrogen <20 ppm), or methane and hydrogen positive (M+/H+) (methane ≥3 ppm and hydrogen ≥20 ppm]. There were significant differences in age but not in gender across the groups. After controlling for age as a confounding variable, M+/H+ subjects had significantly higher BMI than other groups (N: 24.1 ± 5.2 kg/m(2); H+: 24.2 ± 4.5 kg/m(2); M+: 24.0 ± 3.75 kg/m(2); M+/H+: 26.5 ± 7.1 kg/m(2), P < .02) and also had significantly higher percent body fat (N: 28.3 ± 10.0%; H+: 27.5 ± 9.0%; M+: 28.0 ± 8.9%; M+/H+; 34.1 ± 10.9%, P < .001). The presence of both methane and hydrogen on breath testing is associated with increased BMI and percent body fat in humans. We hypothesize that this is due to colonization with the hydrogen-requiring M smithii, which affects nutrient availability for the host and may contribute to weight gain.

  2. The(13)C-octanoic acid breath test for detection of effects of meal composition on the rate of solid-phase gastric emptying in ponies.

    PubMed

    Wyse, C A; Murphy, D M; Preston, T; Sutton, D G; Morrison, D J; Christley, R M; Love, S

    2001-08-01

    The aim of this study was to apply the(13)C-octanoic acid breath test for detection of alterations in the rate of solid-phase gastric emptying, induced by changes in test meal composition, in ponies. After a 14 hour fast the ponies (n = 4) ingested a test meal with 0, 35 or 70 ml soya oil, and labelled with 250 mg(13)C-octanoic acid. Each pony was given each of the three test meals on three separate occasions, in a randomised order. Exhaled breath samples were collected for 12 hours after ingestion of the test meal. Breath samples were analysed by continuous flow isotope ratio mass spectrometry. Three indices of breath(13)C-enrichment were computed, half-dose recovery time (t 1/2), gastric emptying coefficient (GEC) and time to peak breath(13)C-excretion t(max). The(13)C-octanoic acid breath test was a reliable means of assessing the significantly decreased rate of gastric emptying in the pony, associated with addition of soya oil to the test meal. Copyright 2001 Harcourt Publishers Ltd.

  3. Breathing difficulty

    MedlinePlus

    ... pulmonary disease (COPD), such as chronic bronchitis or emphysema Other lung disease Pneumonia Pulmonary hypertension Problems with ... of breath; Breathlessness; Difficulty breathing; Dyspnea Images Lungs Emphysema References Kraft M. Approach to the patient with ...

  4. Breathing Problems

    MedlinePlus

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  5. Drink driving in Hong Kong: the competing effects of random breath testing and alcohol tax reductions.

    PubMed

    Kim, Jean H; Wong, Alvin H; Goggins, William B; Lau, Joseph; Griffiths, Sian M

    2013-07-01

    To investigate the competing effects of increased anti-drink driving legislation and the recent elimination of excise taxes on wine and beer. Serial cross-sectional telephone surveys were conducted in 2006 (n = 9860) and 2011 (n = 4800). Hong Kong, China. Chinese adults (≥18 years of age). Respondents were asked about their drinking patterns, past-year experience of driving within 2 hours of drinking, drinking-related attitudes and reported deterrents to drink driving. Following the legislative changes, the age-standardized past-year prevalence of drink driving decreased significantly from 5.2 to 2.8% (P < 0.001) among all males, from 9.0 to 4.4% (P < 0.001) among male past-year drinkers and from 13.7 to 8.5% (P < 0.01) among male weekly drinkers. The past-year prevalence of drink driving in 2011 among all females (0.08%), female past-year drinkers (1.6%), male binge drinkers (12.5%), female weekly drinkers (4.7%) and female binge drinkers (7.9%) were not significantly different from 2006. Drink driving was associated independently with business sector employment [odds ratio (OR) = 2.47], past-month binge drinking (OR = 6.08) and beliefs in the benefits to one's wellbeing of drinking (OR = 2.62) among males and past-month binge drinking (OR = 5.57), belief in the social benefits of drinking (OR = 5.66) and being unmarried (OR = 3.00) in females (P < 0.05). The most commonly reported drink driving deterrents were concerns about random breath tests (93.8%) and the potential legal consequences of conviction (93.6-96.5%). Despite greater alcohol consumption in Hong Kong, the current anti-drink driving strategy appears to reduce drink driving in males and prevent increased levels among females. Binge drinkers, however, remain a high-risk group that should be monitored continually. © 2013 The Authors, Addiction © 2013 Society for the Study of Addiction.

  6. Breath holding spell

    MedlinePlus

    ... such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells ( ... tests may be done to check for an iron deficiency. Other tests that may be done include: EKG ...

  7. Exercise training improves breathing strategy and performance during the six-minute walk test in obese adolescents.

    PubMed

    Mendelson, Monique; Michallet, Anne-Sophie; Perrin, Claudine; Levy, Patrick; Wuyam, Bernard; Flore, Patrice

    2014-08-15

    We aimed to examine ventilatory responses during the six-minute walk test in healthy-weight and obese adolescents before and after exercise training. Twenty obese adolescents (OB) (age: 14.5±1.7 years; BMI: 34.0±4.7kg·m(-2)) and 20 age and gender-matched healthy-weight adolescents (HW) (age: 15.5±1.5 years; BMI: 19.9±1.4kg·m(-2)) completed six-minute walk test during which breath-by-breath gas analysis and expiratory flow limitation (expFL) were measured. OB participated in a 12-week exercise-training program. Comparison between HW and OB participants showed lower distance achieved during the 6MWT in OB (-111.0m, 95%CI: -160.1 to 62.0, p<0.05) and exertional breathlessness was greater (+0.78 a.u., 95%CI: 0.091-3.27, p=0.039) when compared with HW. Obese adolescents breathed at lower lung volumes, as evidenced by lower end expiratory and end inspiratory lung volumes during exercise (p<0.05). Prevalence of expFL (8 OB vs 2 HW, p=0.028) and mean expFL (14.9±21.9 vs 5.32±14.6% VT, p=0.043, in OB and HW) were greater in OB. After exercise training, mean increase in the distance achieved during the 6MWT was 64.5 meters (95%CI: 28.1-100.9, p=0.014) and mean decrease in exertional breathlessness was 1.62 (95%CI: 0.47-2.71, p=0.05). Obese adolescents breathed at higher lung volumes, as evidenced by the increase in end inspiratory lung volume from rest to 6-min exercise (9.9±13.4 vs 20.0±13.6%TLC, p<0.05). Improved performance was associated with improved change in end inspiratory lung volume from rest to 6-min exercise (r=0.65, p=0.025). Our results suggest that exercise training can improve breathing strategy during submaximal exercise in obese adolescents and that this increase is associated with greater exercise performance. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Further characterization of a ¹³C-dextromethorphan breath test for CYP2D6 phenotyping in breast cancer patients on tamoxifen therapy.

    PubMed

    Opdam, F L; Modak, A S; Gelderblom, H; Guchelaar, H J

    2015-04-20

    In a previous study, we found that the CYP2D6 phenotype determined by (13)C-dextromethorphan breath test (DM-BT) might be used to predict tamoxifen treatment outcome in breast cancer patients in the adjuvant setting. However, large variation in the delta-over-baseline (DOB) values was observed in the extensive metabolizer predicted phenotype group based on single point measures. In the present work we aimed to analyze the variability of phenotype results and determine reproducibility to further characterize the clinical utility of DM-BT by introducing multiple breath sampling instead of single breath sampling and by administration of a fixed dose of (13)C-DM.

  9. Lamaze Breathing

    PubMed Central

    Lothian, Judith A.

    2011-01-01

    Lamaze breathing historically is considered the hallmark of Lamaze preparation for childbirth. This column discusses breathing in the larger context of contemporary Lamaze. Controlled breathing enhances relaxation and decreases perception of pain. It is one of many comfort strategies taught in Lamaze classes. In restricted birthing environments, breathing may be the only nonpharmacological comfort strategy available to women. Conscious breathing and relaxation, especially in combination with a wide variety of comfort strategies, can help women avoid unnecessary medical intervention and have a safe, healthy birth. PMID:22379360

  10. Correlation of single-breath count test and neck flexor muscle strength with spirometry in myasthenia gravis

    PubMed Central

    Elsheikh, Bakri; Arnold, W. David; Gharibshahi, Shahram; Reynolds, Jerold; Freimer, Miriam; Kissel, John T.

    2015-01-01

    Introduction Although formal spirometry is the gold standard for monitoring respiratory function in patients with myasthenia gravis (MG), such testing is often delayed or unavailable. There is a need for a simple bedside test that can accurately measure respiratory function. Method We conducted a prospective, cross-sectional, single-blind study in adults with acetylcholine receptor antibody positive MG. Participants performed the single breath count test (SBCT) and underwent manual muscle strength testing, while a respiratory therapist performed spirometry blinded to SBCT and strength results. Results Thirty-one patients, aged 57 ±19 years participated. SBCT showed significant correlations with forced vital capacity (FVC), negative inspiratory force (NIF), and neck flexor strength (P<0.01). FVC showed significant correlation with neck flexor strength (P=0.02) but no correlation with shoulder abductor strength. Discussion These data suggest that the SBCT and neck flexor strength testing are valuable tools for bedside assessment of respiratory function in MG patients. PMID:26437790

  11. Performance of Helicobacter pylori acid extract and urease enzyme-linked immunosorbent assays in relation to 14C-urea breath test.

    PubMed

    von Wulffen, H; Gatermann, S; Windler, E; Gabbe, E; Heinrich, H C

    1993-09-01

    The 14C-urea breath test has been shown to be a reliable non-invasive method to detect the presence or absence of H. pylori infection. Alternatively, a number of techniques have been devised to detect circulating antibodies against H. pylori in serum, the most commonly used being enzyme-linked immunosorbent assays (ELISA). In the present study we compared the value of two ELISA antigen preparations, an acid glycine extract and a urease preparation, in relation to the results achieved in a 14C-urea breath test. Seventy-five gastroenterology outpatients were screened for the presence of H. pylori infection using the urea breath test. At the same time serum specimens were obtained. Thirty-seven patients had a positive breath test, i.e. they expired more than 2% of the oral 14C test dose within 60 min. Using the breath test as reference, sensitivity and specificity for the acid extract were 89.2% and 84.2% respectively, and for the urease ELISA 81.1% and 89.5%. Agreement between the two ELISAs was found in 82.7%, overall agreement between all three tests was observed in 77.3%. All three tests were found to be useful for monitoring therapy directed against H. pylori.

  12. Manned Test and Evaluation of Morgan Breathing System 2000 (MBS 2000) Oxygen Monitoring System

    DTIC Science & Technology

    2010-05-01

    19. ABSTRACT: The MBS 2000 is an O2 rebreather intended for O2 decompression use in a dry chamber. Users purge the breathing loop with O2 at preset...The MBS 2000 is an O2 rebreather intended for use in a dry chamber by submariners removed from a pressurized submarine. Currently, MBS 2000 users...system (OMS) in the MBS 2000 rebreather consists of an O2 sensor that measures O2 partial pressure (PO2), not the fraction of O2 (FO2), in the inspired

  13. Breath hydrogen test for detecting lactose malabsorption in infants and children. Prevalence of lactose malabsorption in Japanese children and adults.

    PubMed Central

    Nose, O; Iida, Y; Kai, H; Harada, T; Ogawa, M; Yabuuchi, H

    1979-01-01

    The breath hydrogen test (BHT) was adapted for use in young infants and children. The diagnostic criterion of sugar malabsorption in the BHT was determined by oral administration of 0.5 g/kg of unabsorbable sugar (lactulose) to 21 healthy infants and children. A maximum increase in breath hydrogen less than 0.05 ml/min per m2 was observed in all subjects. A good correlation between results by the BHT and by the ordinary lactose tolerance test was obtained after oral administration of 2 g/kg lactose to 21 healthy infants and children, 2 congenital lactase-deficient infants, and 7 adults. Using this test, 80 healthy Japanese infants and children (aged between one month and 15 years) and 18 adults were examined for lactose malabsorption after a dose of 1 g/kg lactose. All infants and children under 2-years old absorbed lactose completely. The incidence of lactose malabsorption was 30% in 3-year, 36% in 4-year, 58% in 5-year, and 86% in 6-year-old children, 85% in schoolchildren, and 89% in adults. Thus the incidence of lactase deficiency gradually increases with age from 3 years, and about 90% of all normal Japanese adults are lactase-deficient. PMID:475426

  14. Breath hydrogen test for detecting lactose malabsorption in infants and children. Prevalence of lactose malabsorption in Japanese children and adults.

    PubMed

    Nose, O; Iida, Y; Kai, H; Harada, T; Ogawa, M; Yabuuchi, H

    1979-06-01

    The breath hydrogen test (BHT) was adapted for use in young infants and children. The diagnostic criterion of sugar malabsorption in the BHT was determined by oral administration of 0.5 g/kg of unabsorbable sugar (lactulose) to 21 healthy infants and children. A maximum increase in breath hydrogen less than 0.05 ml/min per m2 was observed in all subjects. A good correlation between results by the BHT and by the ordinary lactose tolerance test was obtained after oral administration of 2 g/kg lactose to 21 healthy infants and children, 2 congenital lactase-deficient infants, and 7 adults. Using this test, 80 healthy Japanese infants and children (aged between one month and 15 years) and 18 adults were examined for lactose malabsorption after a dose of 1 g/kg lactose. All infants and children under 2-years old absorbed lactose completely. The incidence of lactose malabsorption was 30% in 3-year, 36% in 4-year, 58% in 5-year, and 86% in 6-year-old children, 85% in schoolchildren, and 89% in adults. Thus the incidence of lactase deficiency gradually increases with age from 3 years, and about 90% of all normal Japanese adults are lactase-deficient.

  15. Diving and foraging patterns of Marbled Murrelets (Brachyramphus marmoratus): Testing predictions from optimal-breathing models

    USGS Publications Warehouse

    Jodice, Patrick G.; Collopy, M.W.

    1999-01-01

    The diving behavior of Marbled Murrelets (Brachyramphus marmoratus) was studied using telemetry along the Oregon coast during the 1995 and 1996 breeding seasons and examined in relation to predictions from optimal-breathing models. Duration of dives, pauses, dive bouts, time spent under water during dive bouts, and nondiving intervals between successive dive bouts were recorded. Most diving metrics differed between years but not with oceanographic conditions or shore type. There was no effect of water depth on mean dive time or percent time spent under water even though dive bouts occurred in depths from 3 to 36 m. There was a significant, positive relationship between mean dive time and mean pause time at the dive-bout scale each year. At the dive-cycle scale, there was a significant positive relationship between dive time and preceding pause time in each year and a significant positive relationship between dive time and ensuing pause time in 1996. Although it appears that aerobic diving was the norm, there appeared to be an increase in anaerobic diving in 1996. The diving performance of Marbled Murrelets in this study appeared to be affected by annual changes in environmental conditions and prey resources but did not consistently fit predictions from optimal-breathing models.

  16. Modified Helicobacter test using a new test meal and a (13)C-urea breath test in Helicobacter pylori positive and negative dyspepsia patients on proton pump inhibitors.

    PubMed

    Tepeš, Bojan; Malfertheiner, Peter; Labenz, Joachim; Aygen, Sitke

    2017-08-28

    To determine the sensitivity and specificity of the (13)C-urea breath test (UBT) in patients taking proton pump inhibitors (PPIs), using a new test meal Refex. One hundred and fourteen consecutive patients with dyspepsia, 53 Helicobacter pylori (H. pylori) positive, 49 H. pylori negative, were included in the study. The patients were then given esomeprazole 40 mg for 29 consecutive days, and the (13)C-UBT with the new test meal was performed the next morning. The sensitivity of the (13)C-UBT with a cut off 2.5‰ was 92.45% (95%CI: 81.79%-97.91%) by per-protocol (PP) analysis and 78.13% (95%CI: 66.03%-87.49%) by intention-to-treat (ITT) analysis. The specificity of the (13)C-UBT test was 96.00% in the ITT population (95%CI: 86.29%-99.51%) and 97.96% in the PP population (95%CI: 89.15%-99.95%). The new test meal based (13)C-UBT is highly accurate in patients on PPIs and can be used in those unable to stop their PPI treatment.

  17. Assessment of the reproducibility of the lactulose H2 breath test as a measure of mouth to caecum transit time.

    PubMed Central

    La Brooy, S J; Male, P J; Beavis, A K; Misiewicz, J J

    1983-01-01

    The lactulose H2 breath test is in use as a simple non-invasive measurement of mouth to caecum transit time, but its reproducibility has never been assessed. We have examined the reproducibility of mouth to caecum transit time in 21 normal subjects using lactulose 10, 15, and 20 g; seven subjects being studied with 10 g and 12 each with 15 and 20 g doses. Transit time decreased with increasing doses of lactulose although the differences were not significant between or within (n = 5) individuals. Variation in transit times between individuals was considerable with all doses of lactulose (mean coefficient of variation of 18.5, 29.7 and 28.3% with 10, 15, and 20 g respectively). The addition of lactulose to a liquid meal containing carbohydrate, fat, and protein decreased the coefficient of variation to less than 10% in four subjects studied. The lactulose H2 breath test could be made more reproducible by including a liquid meal. PMID:6618268

  18. [14C]Urea breath test is not sensitive for detection of acute Helicobacter pylori infection in rhesus monkeys (Macaca mulatta).

    PubMed

    Solnick, Jay V; Hansen, Lori M; Canfield, Don R

    2002-02-01

    The urea breath test is sensitive and specific for detection of chronic infection with H. pylori. We sought to determine the sensitivity of the [14C]urea breath test for detection of acute H. pylori infection using experimentally infected rhesus monkeys. Eighteen monkeys were inoculated with H. pylori. Serial [14C]urea breath tests and cultures of gastric biopsies were performed before and up to 10 weeks after inoculation. Cultures from all 18 monkeys were positive for H. pylori at each time point. The sensitivity of the [14C]urea breath test increased systematically from 43% at two weeks after inoculation up to 93% at 10 weeks after inoculation. Quantitative cultures of H. pylori showed a tendency to decline over time following inoculation. We conclude that the [14C]urea breath test is not sensitive for detection of acute H. pylori infection in rhesus monkeys until 10 weeks after inoculation. While this may reflect a gradual increase in bacterial load that was not detected by limited sampling, our data are not consistent with this hypothesis.

  19. Fabry-Perot microcavity sensor for H2-breath-test analysis

    NASA Astrophysics Data System (ADS)

    Vincenti, Maria Antonietta; De Sario, Marco; Petruzzelli, V.; D'Orazio, Antonella; Prudenzano, Francesco; de Ceglia, Domenico; Scalora, Michael

    2007-10-01

    Leak detection of hydrogen for medical purposes, based on the monitoring of the optical response of a simple Fabry-Perot microcavity, is proposed to investigate either the occurrence of lactose intolerance, or lactose malabsorption condition. Both pathologic conditions result in bacterial overgrowth in the intestine, which causes increased spontaneous emission of H2 in the human breath. Two sensitivity figures of merit are introduced to inspect changes in the sensor response, and to relate the microcavity response to a pathologic condition, which is strictly related to a different level of exhaled hydrogen. Different sensor configurations using a metal-dielectric microcavity are reported and discussed in order to make the most of the well-known ability of palladium to spontaneously absorb hydrogen.

  20. Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment.

    PubMed

    Pohl, D; Savarino, E; Hersberger, M; Behlis, Z; Stutz, B; Goetze, O; Eckardstein, A V; Fried, M; Tutuian, R

    2010-09-01

    Clinical manifestations of lactase (LCT) deficiency include intestinal and extra-intestinal symptoms. Lactose hydrogen breath test (H2-BT) is considered the gold standard to evaluate LCT deficiency (LD). Recently, the single-nucleotide polymorphism C/T(-13910) has been associated with LD. The objectives of the present study were to evaluate the agreement between genetic testing of LCT C/T(-13910) and lactose H2-BT, and the diagnostic value of extended symptom assessment. Of the 201 patients included in the study, 194 (139 females; mean age 38, range 17-79 years, and 55 males, mean age 38, range 18-68 years) patients with clinical suspicion of LD underwent a 3-4 h H2-BT and genetic testing for LCT C/T(-13910). Patients rated five intestinal and four extra-intestinal symptoms during the H2-BT and then at home for the following 48 h. Declaring H2-BT as the gold standard, the CC(-13910) genotype had a sensitivity of 97% and a specificity of 95% with a κ of 0.9 in diagnosing LCT deficiency. Patients with LD had more intense intestinal symptoms 4 h following the lactose challenge included in the H2-BT. We found no difference in the intensity of extra-intestinal symptoms between patients with and without LD. Symptom assessment yielded differences for intestinal symptoms abdominal pain, bloating, borborygmi and diarrhoea between 120 min and 4 h after oral lactose challenge. Extra-intestinal symptoms (dizziness, headache and myalgia) and extension of symptom assessment up to 48 h did not consistently show different results. In conclusion, genetic testing has an excellent agreement with the standard lactose H2-BT, and it may replace breath testing for the diagnosis of LD. Extended symptom scores and assessment of extra-intestinal symptoms have limited diagnostic value in the evaluation of LD.

  1. An experimental evaluation of the use of C3 δ13C plant tissue as a proxy for the paleoatmospheric δ13CO2 signature of air

    NASA Astrophysics Data System (ADS)

    Lomax, B. H.; Knight, C. A.; Lake, J. A.

    2012-09-01

    Previous work suggests that the relationship between the carbon isotope composition of air (δ13Ca) and plant leaf tissue (δ13Cp) can be used to track changes in the carbon isotope composition of paleo-atmospheric CO2. Here we test this assertion in a series of experiments using the model plant Arabidopsis thaliana grown under a range of atmospheric CO2 concentrations relevant to geologic time (380, 760, 1000, 1500, 2000 and 3000 ppm). Nested within these CO2 experiments water availability was controlled (giving two sets of experimental plants; low and high water treatment at each CO2 concentration) to manipulate stomatal opening, a key process governing carbon fixation and isotope discrimination. Results show a highly significant relationship between δ13Ca and δ13Cp under both experimental water treatments. To test the utility of δ13Cp to predict δ13Ca we compare calculated δ13Ca to measured values of δ13Ca. These data show that although there is a significant relationship between calculated and measured δ13Ca, there is disparity between the two values of δ13Ca and a large difference between calculated values under different water treatments even when grown in a common CO2 concentration. These results demonstrate that environmental factors that alter stomatal opening can severely impact on the use and reliability of δ13Cp to predict δ13Ca and as such, results should be interpreted with caution.

  2. Quantification of Helicobacter pylori infection in gastritis and ulcer disease using a simple and rapid carbon-14-urea breath test

    SciTech Connect

    Debongnie, J.C.; Pauwels, S.; Raat, A.; de Meeus, Y.; Haot, J.; Mainguet, P. )

    1991-06-01

    Gastric urease was studied isotopically in 230 patients with biopsy-proven normal mucosa or chronic gastritis, including 59 patients with ulcer disease. Carbon-14-urea was given in 25 ml of water without substrate carrier or nutrient-dense meal, and breath samples were collected over a 60-min period. The amount of 14CO2 excreted at 10 min was independent of the rate of gastric emptying and was not quantitatively influenced by the buccal urease activity. The 10-min 14CO2 values discriminated well between Helicobacter pylori positive and negative patients (94% sensitivity, 89% specificity) and correlated with the number of organisms assessed by histology. The test was a good predictor of chronic gastritis (95% sensitivity and 96% specificity), and a quantitative relationship was observed between 14CO2 values and the severity and activity of the gastritis. In H. pylori positive patients, breath 14CO2 was found to be similar in patients with and without ulcer disease, suggesting that the number of bacteria is not a determining factor for the onset of ulceration.

  3. Effects of low oxygen dead space ventilation and breath-holding test in evaluating cerebrovascular reactivity: A comparative observation.

    PubMed

    Ju, Ke-Ju; Zhong, Ling-Ling; Ni, Xiao-Yu; Xia, Lei; Xue, Liu-Jun; Cheng, Guan-Liang

    2017-01-01

    This study aims to explore the application prospect of low oxygen dead space ventilation (LODSV) in evaluating vasomotor reactivity (VMR) by comparison between LODSV and breath-holding test (BHT). Outpatient or inpatient patients who underwent transcranial Doppler sonography (TCD) were enrolled into this study. These patients successively underwent BHT and LODSV. The cooperation degree, tolerance conditions and adverse reactions in patients were recorded, and VMR was calculated, compared and analyzed. Patients had poor cooperation during BHT. Except for compensatory tachypnea after BHT, patients basically had no adverse reaction. The main manifestations of patients undergoing LODSV were deepened breathing and accelerated frequency in the end of the ventilation, and increased heart rate and a slight decline in pulse oxygen that rapidly recovered after ventilation. The increase rate of blood flow velocity in patients undergoing LODSV was significantly higher than in BHT (P<0.001), and its calculated VMR value was approximately 15% higher than BHT (P<0.001). BHT revealed a monophasic curve that slightly descends and rapidly increases, and LODSV revealed a curve that descends for a short time and slowly increases with a platform. LODSV can effectively eliminate the affect of poor cooperation in patients, and avoid intolerance caused by hypoxia. Hence, VMR value is more accurate than that determined by BHT; and this can reflect the maximum reaction ability of the blood vessels. Therefore, this method has higher clinical application value.

  4. A comparison between lactose breath test and quick test on duodenal biopsies for diagnosing lactase deficiency in patients with self-reported lactose intolerance.

    PubMed

    Furnari, Manuele; Bonfanti, Daria; Parodi, Andrea; Franzè, Jolanda; Savarino, Edoardo; Bruzzone, Luca; Moscatelli, Alessandro; Di Mario, Francesco; Dulbecco, Pietro; Savarino, Vincenzo

    2013-02-01

    A lactose breath test (LBT) is usually used to diagnose lactase deficiency, and a lactose quick test (LQT) has been proposed as a new test on duodenal biopsies to detect this disorder. We aimed to assess the diagnostic accuracy of LBT and LQT and their ability to predict the clinical response to a lactose-free diet in patients with self-reported lactose intolerance. Fifty-five patients (age 47 ± 14 y; M/F 15/36) underwent upper gastrointestinal endoscopy and 25g-LBT. Two duodenal biopsies were taken to determine lactase deficiency (normal, mild, or severe) by LQT and to rule out other causes of secondary lactose malabsorption. Patients with a positive LBT and normal LQT also underwent a glucose breath test to exclude small intestinal bacterial overgrowth as a cause of the former result. The severity of gastrointestinal symptoms was measured with a GSS questionnaire, under basal condition and 1 month after a lactose-free diet. Lactose malabsorption was detected in 31/51 patients with LBT and in 37/51 patients with LQT (P = NS). Celiac disease was found in 2 patients. Two LBT+ patients showed a positive glucose breath test for small intestinal bacterial overgrowth. Eight patients had a mild hypolactasia by LQT and a negative LBT, but they had a significant improvement of symptoms after diet. LQT and LBT were concordant in 83% of cases and predicted the response to a lactose-free diet in 98% and 81% of the cases, respectively (P = 0.03). LQT is as sensitive as LBT in detecting lactase deficiency; however, it seems to be more accurate than LBT in predicting the clinical response to a lactose-free diet.

  5. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  6. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  7. Carbon-13 urea breath test for Helicobacter pylori infection in patients with uninvestigated ulcer-like dyspepsia: an evidence-based analysis.

    PubMed

    Ling, D

    2013-01-01

    Dyspepsia is a condition defined by chronic pain or discomfort in the upper gastrointestinal tract that can be caused by Helicobacter pylori. The carbon-13 urea breath test (¹³C UBT) is a non-invasive test to detect H. pylori. We aimed to determine the diagnostic accuracy and clinical utility of the ¹³C UBT in adult patients with ulcer-like dyspepsia who have no alarm features. A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2003 and 2012. We abstracted the sensitivity and specificity, which were calculated against a composite reference standard. Summary estimates were obtained using bivariate random effects regression analysis. From 19 diagnostic studies, the ¹³C UBT summary estimates were 98.1% (95% confidence interval [CI], 96.3-99.0) for sensitivity and 95.1% (95% CI, 90.3-97.6) for specificity. In 6 studies that compared the ¹³C UBT with serology, the 1¹³C UBT sensitivity was 95.0% (95% CI, 90.1-97.5) and specificity was 91.6 % (95% CI, 81.3-96.4). The sensitivity and specificity for serology were 92.9% (95% CI, 82.6-97.3) and 71.1% (95% CI, 63.8-77.5), respectively. In 1 RCT, symptom resolution, medication use, and physician visits were similar among the ¹³C UBT, serology, gastroscopy, or empirical treatment arms. However, patients tested with ¹³C UBT reported higher dyspepsia-specific quality of life scores. Processing of the ¹³C UBT results can vary according to many factors. Further, the studies showed significant heterogeneity and used different composite reference standards. The ¹³C UBT is an accurate test with high sensitivity and specificity. Compared with serology, it has higher specificity. There is a paucity of data on the ¹³C UBT beyond test accuracy. Breath test for detecting bacteria in patients with ulcer-like symptoms. Dyspepsia is a

  8. [Accuracy of lactase gene C/T-13910 polymorphism and hydrogen breath test in a gastroenterology outpatient clinic: a retrospective study].

    PubMed

    Buzás, György; Fodor, Flóra; Csókay, Béla

    2016-06-19

    Adult type hypolactasia is the most prevalent carbohydrate malabsorption. To assess the distribution of lactase gene C/T-13910 polymorphism and the accuracy and concordance of a genetic test and H(2) breath test in the diagnosis of adult type hypolactasia. 496 patients with symptoms of lactose intolerance were enrolled in a retrospective study who underwent genetic test using TaqMan polymerase chain reaction and H(2) breath test. The prevalence of C/T-13910 genotypes was: CC 48.1%, TC: 40.5%, and TT: 11.4%. When the genetic test was taken as reference, the sensitivity of the breath test was 84.3%, with a specificity of 95.7%, a positive predictive value of 96.7% and negative predictive value of 80.4%. Conversely, the accuracy of genetic test was: sensitivity 96.6%, specificity 80.4%, positive predictive value 84.3% and negative predictive value 95.7%. The concordance value between the two tests (kappa index) was 0.78. The results were discordant in 11.1% of the cases. In symptomatic patients, the lactase non-persistence genotype CC occurred in almost half of the patients. Both the genetic and the breath tests are sufficiently accurate, with good predictive value and they can be used to set up the diagnosis. Discordant results should be carefully interpreted.

  9. Selection of a cut-off for high- and low-methane producers using a spot-methane breath test: results from a large north American dataset of hydrogen, methane and carbon dioxide measurements in breath.

    PubMed

    Gottlieb, Klaus; Le, Chenxiong; Wacher, Vince; Sliman, Joe; Cruz, Christine; Porter, Tyler; Carter, Stephen

    2017-01-27

    Levels of breath methane, together with breath hydrogen, are determined by means of repeated collections of both, following ingestion of a carbohydrate substrate, at 15-20 minutes intervals, until 10 samples have been obtained. The frequent sampling is required to capture a rise of hydrogen emissions, which typically occur later in the test: in contrast, methane levels are typically elevated at baseline. If methane emissions represent the principal objective of the test, a spot methane test (i.e. a single-time-point sample taken after an overnight fast without administration of substrate) may be sufficient. We analysed 10-sample lactulose breath test data from 11 674 consecutive unique subjects who submitted samples to Commonwealth Laboratories (Salem, MA, USA) from sites in all of the states of the USA over a one-year period. The North American Consensus (NAC) guidelines criteria for breath testing served as a reference standard. The overall prevalence of methane-positive subjects (by NAC criteria) was 20.4%, based on corrected methane results, and 18.9% based on raw data. In our USA dataset, the optimal cut-off level to maximize sensitivity and specificity was ≥4 ppm CH4, 94.5% [confidential interval (CI): 93.5-95.4%] and 95.0% (CI: 94.6-95.5%), respectively. The use of a correction factor (CF) (5% CO2 as numerator) led to reclassifications CH4-high to CH4-low in 0.7 % and CH4-low to CH4-high in 2.1%. A cut-off value for methane at baseline of either ≥4 ppm, as in our USA dataset, or ≥ 5 ppm, as described in a single institution study, are both highly accurate in identifying subjects at baseline that would be diagnosed as 'methane-positive' in a 10-sample lactulose breath test for small intestinal bacterial overgrowth. © The Author(s) 2017. Published by Oxford University Press and Sixth Affiliated Hospital of Sun Yat-Sen University.

  10. False negative urea breath tests with H2-receptor antagonists: interactions between Helicobacter pylori density and pH.

    PubMed

    Graham, David Y; Opekun, Antone R; Jogi, Medhavi; Yamaoka, Yoshio; Lu, Hong; Reddy, Rita; El-Zimaity, Hala M T

    2004-02-01

    We studied the effects of famotidine, sodium bicarbonate, and citric acid on the 13C-urea breath test (UBT). Helicobacter pylori-infected volunteers received a UBT, 40 mg of famotidine at bedtime, and a second UBT (pudding test meal, 648 mg NaHCO3 tablet then 125 mg of urea in 200 ml of water containing 650 mg of NaHCO3). Experiment 2 consisted of four UBTs. Two were standard citric acid UBTs with 75 mg of urea and 2 g citric acid and two were sequential bicarbonate-citric acid UBTs. Sequential UBTs consisted of administration of a 648 mg bicarbonate tablet with 50 g of Polycose in 200 ml of water. Five minutes later, 125 mg of 13C-urea was given in 75 ml of water containing 650 mg of NaHCO3. Breath samples were collected after 15 minutes. Then, to acutely acidify the stomach, 4 g of citric acid was given in 200 ml of water. A second breath sample was collected 15 minutes after the citric acid. The standard UBTs were done before and after 6 days of famotidine (40 mg b.i.d.). Sequential UBTs were done after 1 and 6 days of famotidine therapy. Gastric biopsies for histology, culture, and mucosal cytokines were assessed before and after 6 days of famotidine. Eighteen subjects participated, 10 in each experiment; seven had endoscopy with biopsy. Famotidine/ bicarbonate resulted an approximately 50% fall in UBT values (p = .021) with 10% becoming negative. The gastric pH increased from 5.1 +/- 0.5 to 6.7 +/- 0.2 (p = .03) although no pH value predicted the occurrence of false negative results. Under famotidine acid suppression, NaHCO3 reduced the delta over baseline (DOB) by 63% (p = .021). This was reversed with citric acid. Histology showed a H2-receptor antagonist-associated increase in the depth of gastric corpus inflammation. H2-receptor antagonists differ from proton pump inhibitors as high intragastric pH may cause a reduction in urease activity, unrelated to a reduced bacterial load and reversed by citric acid.

  11. Prospective evaluation of lactose malabsorption by lactose hydrogen breath test in individuals infected with Entamoeba histolytica and passing cysts.

    PubMed

    Rana, Satya Vati; Bhasin, Deepak Kumar; Vinayak, Virender Kumar

    2004-08-01

    The aim of the present prospective study was to detect lactose malabsorption in subjects in northern India infected with Entamoeba histolytica and passing cysts. The study group included forty-one patients with E. histolytica cysts in at least one of three consecutive faecal samples. Lactose malabsorption was detected by a lactose H2 breath test. The results were compared with those of forty controls subjects. Thirty-two of forty-one (78.0 %) subjects passing E. histolytica cysts had lactose malabsorption compared with seventeen of forty (42.5 %) control subjects (P<0.01). In conclusion, the present study shows that lactose malabsorption is significantly more common in individuals infected with E. histolytica and passing cysts compared with control subjects.

  12. Assessment of the alveolar volume when sampling exhaled gas at different expired volumes in the single breath diffusion test.

    PubMed

    Prediletto, Renato; Fornai, Edo; Catapano, Giosuè; Carli, Cristina

    2007-12-19

    Alveolar volume measured according to the American Thoracic Society-European Respiratory Society (ATS-ERS) guidelines during the single breath diffusion test can be underestimated when there is maldistribution of ventilation. Therefore, the alveolar volume calculated by taking into account the ATS-ERS guidelines was compared to the alveolar volume measured from sequentiallly collected samples of the expired volume in two groups of individuals: COPD patients and healthy individuals. The aim of this study was to investigate the effects of the maldistribution of ventilation on the real estimate of alveolar volume and to evaluate some indicators suggestive of the presence of maldistribution of ventilation. Thirty healthy individuals and fifty patients with moderate-severe COPD were studied. The alveolar volume was measured either according to the ATS-ERS guidelines or considering the whole expired volume subdivided into five quintiles. An index reflecting the non-uniformity of the distribution of ventilation was then derived (DeltaVA/VE). Significant differences were found when comparing the two measurements and the alveolar volume by quintiles appeared to have increased progressively towards residual volume in healthy individuals and much more in COPD patients. Therefore, DeltaVA/VE resulted in an abnormal increase in COPD. The results of our study suggest that the alveolar volume during the single breath diffusion test should be measured through the collection of a sample of expired volume which could be more representative of the overall gas composition, especially in the presence of uneven distribution of ventilation. Further studies aimed at clarifying the final effects of this way of calculating the alveolar volume on the measure of DLCO are needed. DeltaVA/VE is an index that can help assess the severity of inhomogeneity in COPD patients.

  13. Role of 13C-urea breath test in experimental model of Helicobacter pylori infection in mice.

    PubMed

    Santos, António Mário; Lopes, Teresa; Oleastro, Mónica; Chaves, Paula; Cordeiro, Rita; Ferreira, Maria; Pereira, Teresa; Machado, Jorge; Guerreiro, António Sousa

    2011-08-01

    Animal models have been widely used to study Helicobacter pylori infection. Evaluation of H. pylori infection status following experimental inoculation of mice usually requires euthanasia. The (13) C-urea breath test ((13) C-UBT) is both sensitive and specific for detection of H. pylori in humans. Thus, it would be very useful to have such a test with the same accuracy for the follow-up of this infection in animal models of gastric infection. Accordingly, the purpose of this study was to develop and evaluate a (13) C-UBT method for following the course of H. pylori infection in a mouse model. A total of 50 female C57BL/6 mice were gavaged three times with either 10(8) colony-forming units of H. pylori (n=29) or saline solution only (n=21). After 2 months of infection, mice were fasted for 14 hours and (13) C-UBT was performed using 300 μg of (13) C-urea. The mice were killed, and the stomach was removed and processed for immunohistochemistry and PCR. The optimal time for breath sample collection in mice was found to be 15 minutes. The (13) C-UBT cutoff was set at 3.0‰ δPDB. Using PCR as the gold standard, the sensitivity of (13) C-UBT and immunohistochemistry was 96.6 and 72.4%, respectively, while the specificity was 85.7 and 95.2%, respectively. (13) C-UBT was shown to be a reliable method for the detection of H. pylori infection in C57BL/6 mice and was even more accurate than immunohistochemistry. The use of (13) C-UBT in the mouse model of H. pylori infection can be very useful to detect the bacterium without the need to kill the animals in long-term time course studies. © 2011 Blackwell Publishing Ltd.

  14. Perceptions and experiences of random breath testing in Queensland and the self-reported deterrent impact on drunk driving.

    PubMed

    Watson, Barry; Freeman, James

    2007-03-01

    The present study explored the impact of random breath testing (RBT) on the attitudes, perceptions, and self-reported behavior of motorists in the Australian state of Queensland. Particular attention was given to how exposure to RBT impacted motorists' perceived risk of apprehension and self-reported behavior, relative to other variables of interest such as alcohol consumption. The study involved a telephone survey of 780 motorists drawn from throughout the state of Queensland. Participants were volunteers recruited from a random sample of all listed telephone numbers in the state, adjusted according to district population figures. The survey questionnaire collected information relating to the participants' socio-demographic characteristics, drinking and drunk driving behaviors, attitudes toward drunk driving and RBT, and experiences and perceptions of RBT. The analysis indicated that a large proportion of the sample had both observed RBT and been breath tested within the last six months and believed the practice served an important role in improving road safety. However, a considerable percentage also reported drunk driving at least once in the last six months without being detected, with further analysis indicating that the threat of apprehension associated with RBT did not appear to greatly influence their offending behavior. Rather, a higher frequency of alcohol consumption, combined with more favorable attitudes to drunk driving and lower levels of support for RBT, appeared to be associated with offending behavior. While the results confirm the high levels of exposure to RBT achieved in Queensland, the direct impact of recent exposure on drunk driving behavior appears less important than other factors such as alcohol consumption and attitudes to drunk driving and RBT. Further research is required to better understand how recent and lifetime exposure to RBT impacts on motorists' perceived risk of apprehension and subsequent drunk driving behavior.

  15. Tracing of recently assimilated carbon in respiration at high temporal resolution in the field with a tuneable diode laser absorption spectrometer after in situ 13CO2 pulse labelling of 20-year-old beech trees.

    PubMed

    Plain, Caroline; Gerant, Dominique; Maillard, Pascale; Dannoura, Masako; Dong, Yanwen; Zeller, Bernd; Priault, Pierrick; Parent, Florian; Epron, Daniel

    2009-11-01

    The study of the fate of assimilated carbon in respiratory fluxes in the field is needed to resolve the residence and transfer times of carbon in the atmosphere-plant-soil system in forest ecosystems, but it requires high frequency measurements of the isotopic composition of evolved CO2. We developed a closed transparent chamber to label the whole crown of a tree and a labelling system capable of delivering a 3-h pulse of 99% 13CO2 in the field. The isotopic compositions of trunk and soil CO2 effluxes were recorded continuously on two labelled and one control trees by a tuneable diode laser absorption spectrometer during a 2-month chase period following the late summer labelling. The lag times for trunk CO2 effluxes are consistent with a phloem sap velocity of about 1 m h(-1). The isotopic composition (delta13C) of CO2 efflux from the trunk was maximal 2-3 days after labelling and declined thereafter following two exponential decays with a half-life of 2-8 days for the first and a half-life of 15-16 days for the second. The isotopic composition of the soil CO2 efflux was maximal 3-4 days after labelling and the decline was also well fitted with a sum of two exponential functions with a half-life of 3-5 days for the first exponential and a half-life of 16-18 days for the second. The amount of label recovered in CO2 efflux was around 10-15% of the assimilated 13CO2 for soil and 5-13% for trunks. As labelling occurred late in the growing season, substantial allocation to storage is expected.

  16. Exhaled Breath Condensate Pepsin: Potential Noninvasive Test for Gastroesophageal Reflux in COPD and Bronchiectasis.

    PubMed

    Lee, Annemarie L; Button, Brenda M; Denehy, Linda; Roberts, Stuart; Bamford, Tiffany; Mu, Fi-Tjen; Mifsud, Nicole; Stirling, Robert; Wilson, John W

    2015-02-01

    Acid gastroesophageal reflux is a common problem in non-cystic fibrosis bronchiectasis and COPD. Invasive methods are used to diagnose gastroesophageal reflux, but the ability to detect pulmonary microaspiration of gastric contents using this method is unclear. A noninvasive option to detect pulmonary microaspiration is to measure pepsin in exhaled breath condensate (EBC), but this has not been related to esophageal pH monitoring in these lung conditions. This study aimed to measure pepsin concentrations and pH in EBC and to determine the relationship to gastroesophageal reflux in bronchiectasis or COPD. Subjects with bronchiectasis (n=10) or COPD (n=10) and control subjects (n=10) completed 24-h esophageal pH monitoring for detection of acid gastroesophageal reflux, measuring the percentage of reflux time in the proximal esophagus and the DeMeester score (DMS). Concurrently, 3 samples of EBC were collected from each subject, and pH was measured and pepsin concentrations were analyzed by enzyme-linked immunosorbent assay. EBC pepsin was detected in subjects with bronchiectasis (44%) or COPD (56%) and in control subjects (10%). A diagnosis of gastroesophageal reflux was not associated with a higher concentration of EBC pepsin in bronchiectasis (P=.21) or COPD (P=.11). EBC pepsin concentration did not correlate with DMS (rs=0.36) or proximal reflux index (rs=0.25) in subjects with bronchiectasis or with DMS (rs=0.28) or proximal reflux index (rs=0.21) in patients with COPD. EBC and sputum pepsin concentrations were moderately correlated in bronchiectasis (rs=0.56) and in COPD (rs=0.43). Pepsin is detectable in EBC samples in bronchiectasis and COPD. Although no association was found between pepsin concentrations and a diagnosis of gastroesophageal reflux, a moderate relationship between sputum and EBC pepsin concentrations suggests that EBC pepsin may be a useful noninvasive marker of pulmonary microaspiration. Copyright © 2015 by Daedalus Enterprises.

  17. Cardiogenic oscillation phase relationships during single-breath tests performed in microgravity

    NASA Technical Reports Server (NTRS)

    Lauzon, A. M.; Elliott, A. R.; Paiva, M.; West, J. B.; Prisk, G. K.

    1998-01-01

    We studied the phase relationships of the cardiogenic oscillations in the phase III portion of single-breath washouts (SBW) in normal gravity (1 G) and in sustained microgravity (microG). The SBW consisted of a vital capacity inspiration of 5% He-1.25% sulfurhexafluoride-balance O2, preceded at residual volume by a 150-ml Ar bolus. Pairs of gas signals, all of which still showed cardiogenic oscillations, were cross-correlated, and their phase difference was expressed as an angle. Phase relationships between inspired gases (e.g., He) and resident gas (n2) showed no change from 1 G (211 +/- 9 degrees) to microG (163 +/- 7 degrees). Ar bolus and He were unaltered between 1 G (173 +/- 15 degrees) and microG (211 +/- 25 degrees), showing that airway closure in microG remains in regions of high specific ventilation and suggesting that airway closure results from lung regions reaching low regional volume near residual volume. In contrast, CO2 reversed phase with He between 1 G (332 +/- 6 degrees) and microG (263 +/- 27 degrees), strongly suggesting that, in microG, areas of high ventilation are associated with high ventilation-perfusion ratio (VA/Q). This widening of the range of VA/Q in microG may explain previous measurements (G.K. Prisk, A.R. Elliott, H.J.B. Guy, J.M. Kosonen, and J.B. West J. Appl. Physiol. 79: 1290-1298, 1995) of an overall unaltered range of VA/Q in microG, despite more homogeneous distributions of both ventilation and perfusion.

  18. Detection of inner tube defects in co-axial circle and Bain breathing systems: a comparison of occlusion and Pethick tests.

    PubMed

    Szypula, K A; Ip, J K; Bogod, D; Yentis, S M

    2008-10-01

    The performance of the occlusion and Pethick tests in detecting faulty inner tubes in co-axial circle and Bain systems was compared. Twelve co-axial circle and 12 Bain anaesthetic breathing systems were tested using the occlusion and the Pethick tests. For each system, three tubes were intact, and the remaining nine had a defect deliberately created in the inner tube (three proximal, three middle and three distal). The investigators were blinded to which of the tubes were defective, and to each other's results. The results showed 100% specificity for both tests. The sensitivity of the occlusion test for detecting faulty breathing systems was found to be good (98%). Our results suggest that the occlusion test should be performed in preference to the Pethick test when testing co-axial circle and Bain systems.

  19. Bad Breath

    MedlinePlus

    ... and soda poor dental hygiene (say: HI-jeen), meaning not brushing and flossing regularly smoking and other tobacco use Poor oral hygiene leads to bad breath because when food particles are left in your mouth, they can rot ...

  20. Bad Breath

    MedlinePlus

    ... for lunch. But certain strong-smelling foods like onions and garlic can cause bad breath. So can ... leave behind strong smells, like cabbage, garlic, raw onions, and coffee. If you’re trying to lose ...

  1. Breath odor

    MedlinePlus

    ... drain their stomach. The breath may have an ammonia-like odor (also described as urine-like or " ... Is there a specific odor (such as fish, ammonia, fruit, feces, or alcohol)? Have you recently eaten ...

  2. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    A description is given of an automatic computer controlled second generation breathing metabolic simulator (BMS). The simulator is used for evaluating and testing respiratory diagnostic, monitoring, support, and resuscitation equipment. Any desired sequence of metabolic activities can be simulated on the device for up to 15 hours. The computer monitors test procedures and provides printouts of test results.

  3. Abdominal adiposity and obstructive airway disease: testing insulin resistance and sleep disordered breathing mechanisms

    PubMed Central

    2012-01-01

    Background This study examined associations of abdominal adiposity with lung function, asthma symptoms and current doctor-diagnosed asthma and mediation by insulin resistance (IR) and sleep disordered breathing (SDB). Methods A random sample of 2500 households was drawn from the community of Whyalla, South Australia (The Whyalla Intergenerational Study of Health, WISH February 2008 - July 2009). Seven-hundred twenty-two randomly selected adults (≥18 years) completed clinical protocols (32.2% response rate). Lung function was measured by spirometry. Post-bronchodilator FEV1/FVC was used to measure airway obstruction and reversibility of FEV1 was calculated. Current asthma was defined by self-reported doctor-diagnosis and evidence of currently active asthma. Symptom scores for asthma (CASS) and SDB were calculated. Intra-abdominal fat (IAF) was estimated using dual-energy x-ray absorptiometry (DXA). IR was calculated from fasting glucose and insulin concentrations. Results The prevalence of current doctor-diagnosed asthma was 19.9% (95% CI 16.7 – 23.5%). The ratio of observed to expected cases given the age and sex distribution of the population was 2.4 (95%CI 2.1, 2.9). IAF was not associated with current doctor-diagnosed asthma, FEV1/FVC or FEV1 reversibility in men or women but was positively associated with CASS independent of IR and SDB in women. A 1% increase in IAF was associated with decreases of 12 mL and 20 mL in FEV1 and FVC respectively in men, and 4 mL and 7 mL respectively in women. SDB mediated 12% and 26% of these associations respectively in men but had minimal effects in women. Conclusions In this population with an excess of doctor-diagnosed asthma, IAF was not a major factor in airway obstruction or doctor-diagnosed asthma, although women with higher IAF perceived more severe asthma symptoms which did not correlate with lower FEV1. Higher IAF was significantly associated with lower FEV1 and FVC and in men SDB mechanisms may

  4. Occult H. pylori infection partially explains ‘false-positive’ results of 13C-urea breath test

    PubMed Central

    Ramírez-Lázaro, María J; Lario, Sergio; Sánchez-Delgado, Jordi; Montserrat, Antònia; Quílez, Elisa M; Casalots, Alex; Suarez, David; Campo, Rafel; Brullet, Enric; Junquera, Félix; Sanfeliu, Isabel; Segura, Ferran

    2015-01-01

    Background In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13C-urea breath test omitting citric acid pre-treatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density ‘occult’ infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an ‘occult’ infection missed by reference tests. Methods Dyspeptic patients (n = 272) were prospectively enrolled and UBiT was performed, according to the manufacturer’s recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated ‘occult’ H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests. Results UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests. Conclusions UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density ‘occult’ H. pylori infection that was undetectable by conventional tests accounted for around 25% of the ‘false-positive’ results. PMID:26535122

  5. Helicobacter pylori Infection in Infants and Toddlers in South America: Concordance between [13C]Urea Breath Test and Monoclonal H. pylori Stool Antigen Test

    PubMed Central

    Saito, Mayuko; Rocha, Gifone Aguiar; Rocha, Andreia Maria Camargos; Melo, Fabrício Freire; Checkley, William; Braga, Lúcia Libanez Bessa C.; Silva, Igor Simões; Gilman, Robert H.

    2013-01-01

    Accurate noninvasive tests for diagnosing Helicobacter pylori infection in very young children are strongly required. We investigated the agreement between the [13C]urea breath test ([13C]UBT) and a monoclonal ELISA (HpSA) for detection of H. pylori antigen in stool. From October 2007 to July 2011, we enrolled 414 infants (123 from Brazil and 291 from Peru) of ages 6 to 30 months. Breath and stool samples were obtained at intervals of at least 3 months from Brazilian (n = 415) and Peruvian (n = 908) infants. [13C]UBT and stool test results concurred with each other in 1,255 (94.86%) cases (kappa coefficient = 0.90; 95% confidence interval [CI] = 0.87 to 0.92). In the H. pylori-positive group, delta-over-baseline (DOB) and optical density (OD) values were positively correlated (r = 0.62; P < 0.001). The positivity of the tests was higher (P < 0.001; odds ratio [OR] = 6.01; 95% CI = 4.50 to 8.04) in Peru (546/878; 62.2%) than in Brazil (81/377; 21.5%) and increased with increasing age in Brazil (P = 0.02), whereas in Peru it decreased with increasing age (P < 0.001). The disagreement between the test results was associated with birth in Brazil and female gender but not with age and diarrhea. Our results suggest that both [13C]UBT and the stool monoclonal test are reliable for diagnosing H. pylori infection in very young children, which will facilitate robust epidemiological studies in infants and toddlers. PMID:24006009

  6. Evaporative emissions in three-day diurnal breathing loss tests on passenger cars for the Japanese market

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroyuki; Inomata, Satoshi; Tanimoto, Hiroshi

    2015-04-01

    Breakthrough emissions that dominate diurnal evaporative emissions from gasoline vehicles were observed in continuous 3-day diurnal breathing loss (DBL) tests. These measurements were conducted on nine vehicles for the Japanese market. Two of these vehicles, made by US and European manufacturers, also meet regulations in their countries of origin. Four vehicles exhibited marked emissions caused by breakthrough emissions during the experimental period, all made by Japanese manufacturers. Using our experimental results, we estimate the total diurnal evaporative emissions from gasoline vehicles in Japan to be 32,792 t y-1. The compositions of the breakthrough and permeation emissions were analyzed in real time using proton transfer reaction plus switchable reagent ion mass spectrometry to estimate the ozone formation potential for the evaporative emissions. The real-time measurements showed that the adsorption of hydrocarbons in a sealed housing evaporative determination unit can result in underestimation, when concentrations are only monitored before and after a DBL test. The composition analysis gave an estimated maximum incremental reactivity (MIR) 20% higher for the breakthrough emissions than for the gasoline that was tested, while the MIR for the permeation emissions was almost the same as the MIR for the fuel. Evaporative emissions from gasoline vehicles in Japan were found to contribute 4.2% to emissions from stationary sources using a mass-based estimate, or 6.1% of emissions from stationary sources using a MIR-based estimate.

  7. Combined sensing platform for advanced diagnostics in exhaled mouse breath

    NASA Astrophysics Data System (ADS)

    Fortes, Paula R.; Wilk, Andreas; Seichter, Felicia; Cajlakovic, Merima; Koestler, Stefan; Ribitsch, Volker; Wachter, Ulrich; Vogt, Josef; Radermacher, Peter; Carter, Chance; Raimundo, Ivo M.; Mizaikoff, Boris

    2013-03-01

    Breath analysis is an attractive non-invasive strategy for early disease recognition or diagnosis, and for therapeutic progression monitoring, as quantitative compositional analysis of breath can be related to biomarker panels provided by a specific physiological condition invoked by e.g., pulmonary diseases, lung cancer, breast cancer, and others. As exhaled breath contains comprehensive information on e.g., the metabolic state, and since in particular volatile organic constituents (VOCs) in exhaled breath may be indicative of certain disease states, analytical techniques for advanced breath diagnostics should be capable of sufficient molecular discrimination and quantification of constituents at ppm-ppb - or even lower - concentration levels. While individual analytical techniques such as e.g., mid-infrared spectroscopy may provide access to a range of relevant molecules, some IR-inactive constituents require the combination of IR sensing schemes with orthogonal analytical tools for extended molecular coverage. Combining mid-infrared hollow waveguides (HWGs) with luminescence sensors (LS) appears particularly attractive, as these complementary analytical techniques allow to simultaneously analyze total CO2 (via luminescence), the 12CO2/13CO2 tracer-to-tracee (TTR) ratio (via IR), selected VOCs (via IR) and O2 (via luminescence) in exhaled breath, yet, establishing a single diagnostic platform as both sensors simultaneously interact with the same breath sample volume. In the present study, we take advantage of a particularly compact (shoebox-size) FTIR spectrometer combined with novel substrate-integrated hollow waveguide (iHWG) recently developed by our research team, and miniaturized fiberoptic luminescence sensors for establishing a multi-constituent breath analysis tool that is ideally compatible with mouse intensive care stations (MICU). Given the low tidal volume and flow of exhaled mouse breath, the TTR is usually determined after sample collection via gas

  8. How to breathe when you are short of breath

    MedlinePlus

    Pursed lip breathing; COPD - pursed lip breathing; Emphysema - pursed lip breathing; Chronic bronchitis - pursed lip breathing; Pulmonary fibrosis - pursed lip breathing; Interstitial lung disease - pursed lip breathing; Hypoxia - pursed lip breathing; ...

  9. An inventory of aeronautical ground research facilities. Volume 2: Air breathing engine test facilities

    NASA Technical Reports Server (NTRS)

    Pirrello, C. J.; Hardin, R. D.; Heckart, M. V.; Brown, K. R.

    1971-01-01

    The inventory covers free jet and direct connect altitude cells, sea level static thrust stands, sea level test cells with ram air, and propulsion wind tunnels. Free jet altitude cells and propulsion wind tunnels are used for evaluation of complete inlet-engine-exhaust nozzle propulsion systems under simulated flight conditions. These facilities are similar in principal of operation and differ primarily in test section concept. The propulsion wind tunnel provides a closed test section and restrains the flow around the test specimen while the free jet is allowed to expand freely. A chamber of large diameter about the free jet is provided in which desired operating pressure levels may be maintained. Sea level test cells with ram air provide controlled, conditioned air directly to the engine face for performance evaluation at low altitude flight conditions. Direct connect altitude cells provide a means of performance evaluation at simulated conditions of Mach number and altitude with air supplied to the flight altitude conditions. Sea level static thrust stands simply provide an instrumented engine mounting for measuring thrust at zero airspeed. While all of these facilities are used for integrated engine testing, a few provide engine component test capability.

  10. Air-breathing aerospace plane development essential: Hypersonic propulsion flight tests

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.

    1995-01-01

    Hypersonic airbreathing propulsion utilizing scramjets can change transatmospheric accelerators for low earth-to-orbit and return transportation. The value and limitation of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. It is proposed that near full-scale hypersonic propulsion flight tests are essential for developing computational design technology so that it can be used for designing this system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests.

  11. Air-breathing aerospace plane development essential: Hypersonic propulsion flight tests

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.

    1995-01-01

    Hypersonic airbreathing propulsion utilizing scramjets can change transatmospheric accelerators for low earth-to-orbit and return transportation. The value and limitation of ground tests, of flight tests, and of computations are presented, and scramjet development requirements are discussed. It is proposed that near full-scale hypersonic propulsion flight tests are essential for developing computational design technology so that it can be used for designing this system. In order to determine how these objectives should be achieved, some lessons learned from past programs are presented. A conceptual two-stage-to-orbit (TSTO) prototype/experimental aerospace plane is recommended as a means of providing access-to-space and for conducting flight tests.

  12. Testing Procedures for Closed-Circuit and Semi-Closed Circuit Underwater Breathing Apparatus

    DTIC Science & Technology

    1974-01-29

    a water or mercury manometer prior to each major test. Recheck calibration at the end of the test. The flowmeters are factory calibrated and should...calibrated against a water or mercury manometer ; the thermisters against 321F. water and room temperature. c. The flowmeter and gauges normally do not need... mercury manometer ; the thermistors against 320 F water and room temperature. 3) The flowmeter and gauges normally do not need daily calibration. 4) All

  13. /sup 14/C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

    SciTech Connect

    Weiss, R.G.; Stryker, J.A.

    1982-02-01

    Thirty patients who were undergoing pelvic radiotherapy had /sup 14/C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested /sup 14/C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p<0.05), and 21.8% at 1 hour postingestion (p<0.05). In Group II, the prercentage reduction were 11.8% and 3.7% at 1/2 and 1 hour, respectively (p>0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption.

  14. /sup 14/C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

    SciTech Connect

    Weiss, R.G.; Stryker, J.A.

    1982-02-01

    Thirty patients who were undergoing pelvic radiotherapy had /sup 14/C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested /sup 14/C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p less than 0.05), and 21.8% at 1 hour postingestion (p less than 0.05). In Group II, the percentage reductions were 11.8% and 3.7% at 1/2 and 1 hour, respectively (p greater than 0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption.

  15. [Cerebral vasoreactivity: Concordance of breath holding test and acetazolamide injection in current practice: 20 cases of asymptomatic carotid artery stenosis].

    PubMed

    De Bortoli, M; Maillet, A; Skopinski, S; Sassoust, G; Constans, J; Boulon, C

    2017-10-01

    Cerebral vasoreactivity (CVR) is the ability of the brain's vascular system to keep cerebral blood inflow stable. Impaired CVR is a risk marker of stroke in patients with asymptomatic carotid stenosis. The gold standard to assess CVR with transcranial ultrasound is acetazolamide (ACTZ) injection. The breath holding test (BHT) might be easier to perform. CVR proved to be efficient in laboratory conditions but not in routine practice. To study the validity of BHT versus ACTZ in routine practice in a vascular exploration unit in patients with asymptomatic carotid stenosis. Study of concordance of BHT and ACTZ, to assess CVR in patients consecutively explored on the same day. Eighteen patients with 20 carotid stenosis were included. The temporal window was missing in 20% of cases. Only 11 out of the 20 procedures were analyzed. Concordance was low between BHT and ACTZ to assess CVR (k=0.3714). BHT cannot replace ACTZ injection. It might be a first-step test so that ACTZ injection might be avoided if CVR is normal. Our present results must be confirmed by further study enrolling many more patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Nissen fundoplication for gastroesophageal reflux: No deterioration of gastric emptying measured by 13C-acetate breath test

    PubMed Central

    Okada, Tadao; Honda, Shohei; Miyagi, Hisayuki; Minato, Masashi

    2011-01-01

    Aim: To study the gastric emptying 30 days after laparoscopic Nissen fundoplication (NF) in gastroesophageal reflux. Materials and Methods: Three patients were evaluated with 13C-acetate breath test (ABT) performed pre and post-NF. The liquid test meal consisted of Racol™ mixed with 13C-acetate. Results: In the patient without neurological impairment (NI), the preoperative t½ex and t lag were 0.900 and 0.510 hours, respectively. The postoperative t½ex and t lag were 0.959 and 0.586 hours, respectively. In one patient with NI, the preoperative t½ex and t lag were 1.828 and 1.092 hours, respectively. The postoperative t½ex and t lag were 2.081 and 1.025 hours, respectively. In the other patient with NI, the preoperative t½ex and t lag were 2.110 and 0.980 hours, respectively. The postoperative t½ex and t lag were 1.118 and 0.415 hours, respectively. Conclusions: Our findings suggest that 13C-ABT parameters did not worsen in any of the children after laparoscopic NF. PMID:22121311

  17. Using eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements, and PhenoCams to constrain a process-based biogeochemical model for carbon market-funded wetland restoration

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Baldocchi, D. D.; Knox, S. H.; Sturtevant, C. S.; Verfaillie, J. G.; Dronova, I.; Jenerette, D.; Poindexter, C.; Huang, Y. W.

    2015-12-01

    We use multiple data streams in a model-data fusion approach to reduce uncertainty in predicting CO2 and CH4 exchange in drained and flooded peatlands. Drained peatlands in the Sacramento-San Joaquin River Delta, California are a strong source of CO2 to the atmosphere and flooded peatlands or wetlands are a strong CO2 sink. However, wetlands are also large sources of CH4 that can offset the greenhouse gas mitigation potential of wetland restoration. Reducing uncertainty in model predictions of annual CO2 and CH4 budgets is critical for including wetland restoration in Cap-and-Trade programs. We have developed and parameterized the Peatland Ecosystem Photosynthesis, Respiration, and Methane Transport model (PEPRMT) in a drained agricultural peatland and a restored wetland. Both ecosystem respiration (Reco) and CH4 production are a function of 2 soil carbon (C) pools (i.e. recently-fixed C and soil organic C), temperature, and water table height. Photosynthesis is predicted using a light use efficiency model. To estimate parameters we use a Markov Chain Monte Carlo approach with an adaptive Metropolis-Hastings algorithm. Multiple data streams are used to constrain model parameters including eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements and digital photography. Digital photography is used to estimate leaf area index, an important input variable for the photosynthesis model. Soil respiration and 13CO2 fluxes allow partitioning of eddy covariance data between Reco and photosynthesis. Partitioned fluxes of CO2 with associated uncertainty are used to parametrize the Reco and photosynthesis models within PEPRMT. Overall, PEPRMT model performance is high. For example, we observe high data-model agreement between modeled and observed partitioned Reco (r2 = 0.68; slope = 1; RMSE = 0.59 g C-CO2 m-2 d-1). Model validation demonstrated the model's ability to accurately predict annual budgets of CO2 and CH4 in a wetland system (within 14% and 1

  18. Just Breathe: The Effects of Emotional Dysregulation and Test Anxiety on GPA

    ERIC Educational Resources Information Center

    Hartman, Samantha D.; Wasieleski, David T.; Whatley, Mark A.

    2017-01-01

    College is considered to be one of the most evaluative and stressful times during a student's academic career. A student's inability to regulate emotions may be correlated with an increased level of test anxiety. Previous research has indicated significant relationships between emotional dysregulation and generalized anxiety disorders (e.g.,…

  19. Purge Procedures and Leak Testing for the Morgan Breathing System (MBS) 2000 Closed-Circuit Oxygen Rebreather

    DTIC Science & Technology

    2005-11-30

    closed- circuit loop using a 3 liter calibrated syringe to determine the magnitude pressure increase that would occur within the closed-circuit loop as a...out. When air was added to the closed circuit breathing loop using the calibrated syringe the pressure within the breathing loop increased once...rig that would not be purged with the use of a Y-valve would be the CO2 canister. After prolonged storage of a prefilled CO2 absorbent canister

  20. Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis

    PubMed Central

    El Shayeb, Mohamed; Topfer, Leigh-Ann; Stafinski, Tania; Pawluk, Lawrence; Menon, Devidas

    2014-01-01

    Background: Greater awareness of sleep-disordered breathing and rising obesity rates have fueled demand for sleep studies. Sleep testing using level 3 portable devices may expedite diagnosis and reduce the costs associated with level 1 in-laboratory polysomnography. We sought to assess the diagnostic accuracy of level 3 testing compared with level 1 testing and to identify the appropriate patient population for each test. Methods: We conducted a systematic review and meta-analysis of comparative studies of level 3 versus level 1 sleep tests in adults with suspected sleep-disordered breathing. We searched 3 research databases and grey literature sources for studies that reported on diagnostic accuracy parameters or disease management after diagnosis. Two reviewers screened the search results, selected potentially relevant studies and extracted data. We used a bivariate mixed-effects binary regression model to estimate summary diagnostic accuracy parameters. Results: We included 59 studies involving a total of 5026 evaluable patients (mostly patients suspected of having obstructive sleep apnea). Of these, 19 studies were included in the meta-analysis. The estimated area under the receiver operating characteristics curve was high, ranging between 0.85 and 0.99 across different levels of disease severity. Summary sensitivity ranged between 0.79 and 0.97, and summary specificity ranged between 0.60 and 0.93 across different apnea–hypopnea cut-offs. We saw no significant difference in the clinical management parameters between patients who underwent either test to receive their diagnosis. Interpretation: Level 3 portable devices showed good diagnostic performance compared with level 1 sleep tests in adult patients with a high pretest probability of moderate to severe obstructive sleep apnea and no unstable comorbidities. For patients suspected of having other types of sleep-disordered breathing or sleep disorders not related to breathing, level 1 testing remains the

  1. U.S.N. Procedures for Testing the Breathing Characteristics of Open Circuit Scuba Regulators

    DTIC Science & Technology

    1973-12-11

    The appropriate sections of MIL-R-24l69A (single-hose SCUBA requlators) are reproduced below: 3.19 Mechanical peak inhalation and exhalation...pressures. - The demand regulator assembly shall exhibit, at a maximum, the values of peak inhalation and exhalation pressures of figure 2 (reproduced as...Mechanical peak inhalation and exhalation pressure test. - The suitability of t e preproduction u-nits for swimming to 201 feet in sea water shall be

  2. Inter-test reproducibility of the lung clearance index measured by multiple breath washout.

    PubMed

    Oude Engberink, Esther; Ratjen, Felix; Davis, Stephanie D; Retsch-Bogart, George; Amin, Reshma; Stanojevic, Sanja

    2017-10-01

    The lung clearance index (LCI) has strong intra-test repeatability; however, the inter-test reproducibility of the LCI is poorly defined.The aim of the present study was to define a physiologically meaningful change in LCI in preschool children, which discriminates changes associated with disease progression from biological variability.Repeated LCI measurements from a longitudinal cohort study of children with cystic fibrosis and age-matched controls were collected to define the inter-visit reproducibility of the LCI. Absolute change, the coefficient of variation, Bland-Altman limits of agreement, the coefficient of repeatability, intra-class correlation coefficient, and percentage changes were calculated.LCI measurements (n=505) from 71 healthy and 77 cystic fibrosis participants (aged 2.6-6 years) were analysed. LCI variability was proportional to its magnitude, such that reproducibility defined by absolute changes is biased. A physiologically relevant change for quarterly LCI measurements in health was defined as exceeding ±15%. In clinically stable cystic fibrosis participants, the threshold was higher (±25%); however, for measurements made 24 h apart, the threshold was similar to that observed in health (±17%).A percentage change in LCI greater than ±15% in preschool children can be considered physiologically relevant and greater than the biological variability of the test. Copyright ©ERS 2017.

  3. [Effect of pharmaceutical care in the diagnosis of Helicobacter pylori infection using 13C-urea breath test].

    PubMed

    Funakoshi, Ryohkan; Yokoyama, Haruko; Kawai, Noriko; Kobayashi, Kenji; Ueno, Fumiaki; Yamada, Yasuhiko

    2012-01-01

    The urea breath test (UBT) is used widely for assessment of Helicobacter pylori (H. pylori) eradication after treatment. A false-negative UBT is common during administration of anti-ulcer drugs and immediately after their discontinuation. It was thought that the pharmaceutical care by the pharmacists was necessary for the diagnostic accuracy of UBT after H. pylori eradication therapy. Therefore, we investigated the effect of pharmaceutical care on diagnosis based on assessment of UBT. The patients who performed UBT were classified into two groups according to the pharmacists' intervention. From 2008 April to 2009 September, the number of the patients taken pharmaceutical care was 57 (intervention group) and that of the patients taken no pharmaceutical care was 62 (control group). When drugs for H. pylori infection and anamnestic therapy were same, the percentage that avoided administration of double drugs was significantly increased by the pharmaceutical care (93.3% in intervention group versus 21.4% in control group, p<0.05). Therefore, the percentage of noncompliance that performed UBT 4 weeks after treatment onward was significantly decreased by the pharmaceutical care (1.6% in intervention group versus 17.5% in control group, p<0.05). Moreover, the percentage of recurrence after treatment was significantly decreased, there were 3.3% in the intervention group and 14.0% in the control group. In conclusion, it was very important that the pharmacists take care in the management of treatment and UBT for H. pylori eradication therapy.

  4. The caffeine breath test and caffeine urinary metabolite ratios in the Michigan cohort exposed to polybrominated biphenyls: A preliminary study

    SciTech Connect

    Lambert, G.H.; Schoeller, D.A.; Kotake, A.N.; Lietz, H. ); Humphrey, H.E.B.; Budd, M. ); Campbell, M.; Kalow, W.; Spielberg, P. )

    1990-11-01

    A field biochemical epidemiology study was conducted using the Michigan cohort consisting of 51 rural residents exposed to polybrominated biphenyls (PBB). The study had three major objectives: (a) to determine the serum half-life of the major PBB congener, hexabromobiphenyl (HBB), in the human, (b) to determine if the PBB-exposed subjects had elevated cytochrome P-450I function as determined by the caffeine breath test (CBT) and the caffeine urinary metabolite ratio (CMR), and (c) to determine the applicability of the CBT and CMR in field studies. PBB serum levels were detected in 36 of the 51 PBB-exposed subjects. The serum half-life of HBB was determined by comparing the current serum HBB values to the subject's previous serum values obtained 5 to 8 years earlier. The median HBB half-life was 12 years (range 4-97 years). The CBT and CMR were elevated in the subjects exposed to PBBs as compared to the values obtained from urban nonsmokers and were similar to those found in adults who smoke. A gender effect was seen in the PBB-exposed subjects. There was a correlation between the CBT and the HBB serum values but not between CMR and HBB serum values. The CBT and CMR were easily conducted in the field and appear to be useful metabolic probes of cytochrome P-450I activity in human environmental toxicology.

  5. DIAGNOSTIC ACCURACY OF UREA BREATH TEST FOR HELICOBACTER PYLORI INFECTION IN CHILDREN WITH DYSPEPSIA IN COMPARISON TO HISTOPATHOLOGY.

    PubMed

    Honar, Naser; Minazadeh, Alireza; Shakibazad, Nader; Haghighat, Mahmood; Saki, Forough; Javaherizadeh, Hazhir

    2016-01-01

    Helicobacter pylori infection is the gram negative bacillus with the close association with chronic antral gastritis. In this study, we evaluate the accuracy of urea breath test (UBT) with carbon isotope 13 in comparison with histopathology of gastric antrum for detection of H. pylori infection in children with dyspepsia. This cross-sectional study was performed at specialized laboratory of Shiraz Gastroenterohepatology Research Center and Nemazee Hospital, Iran, during a 12-months period. This study investigated the sensitivity, specificity, and positive and negative predictive values of UBT in comparison with biopsy-based tests. We included a consecutive selection of 60 children who fulfilled Rome III criteria for dyspepsia. All children were referred for performing UBT with carbon isotope 13 (C13) as well as endoscopy. Biopsies were taken from antrum of stomach and duodenum. The pathologic diagnosis was considered as the standard test. The mean age of the participants was 10.1±2.6 (range 7-17 years). From our total 60 patients, 28 (46.7%) had positive UBT results and 32 (53.3%) had negative UBT results. Pathologic report of 16 (57.1%) out of 28 patients who had positive UBT were positive for H. pylori and 12 (42.9%) ones were negative. Sensitivity and specificity of C13-UBT for detection of H. pylori infection were 76.2% and 69.2% respectively. Sensitivity and specificity of C13-UBT for detection of H. pylori infection were 76.2% and 69.2% respectively. Another multicenter study from our country is recommended.

  6. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  7. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  8. Clinical estimation of mouth breathing.

    PubMed

    Fujimoto, Sachiko; Yamaguchi, Kazunori; Gunjigake, Kaori

    2009-11-01

    Breathing mode was objectively determined by monitoring airflow through the mouth, measuring nasal resistance and lip-seal function, and collecting information via questionnaire on the patient's etiology and symptoms of mouth breathing. The expiratory airflow through the mouth was detected with a carbon dioxide sensor for 30 minutes at rest. Fifteen men and 19 women volunteers (mean age, 22.4 +/- 2.5 years) were classified as nasal breathers, complete mouth breathers, or partial mouth breathers based on the mean duration of mouth breathing. Nasal resistance, lip-sealing function, and the subjective symptoms of mouth breathing ascertained by questionnaire were statistically compared by using 1-way and 2-way analysis of variance (ANOVA) and the chi-square test in the breathing groups. Nasal resistance was significantly (P <0.05) greater for the mouth breathers than for the nasal breathers, and significantly (P <0.05) greater for the partial mouth breathers than for the complete mouth breathers. There were no significant differences in the subjective responses to questions about mouth breathing among the 3 groups. Detecting airflow by carbon dioxide sensor can discriminate breathing mode. Degree of nasal resistance and subjective symptoms of mouth breathing do not accurately predict breathing mode.

  9. Functional (13)C-urea and glucose hydrogen/methane breath tests reveal significant association of small intestinal bacterial overgrowth in individuals with active Helicobacter pylori infection.

    PubMed

    Enko, Dietmar; Kriegshäuser, Gernot

    2017-01-01

    Helicobacter pylori infection is considered to alter the bacterial flora in the upper gastrointestinal tract. This study aimed at investigating the presence of small intestinal bacterial overgrowth (SIBO) in patients with active H. pylori infection assessed by functional breath testing. A total of 109 outpatients, who were referred for the H. pylori(13)C-urea breath test ((13)C-UBT) by general practitioners and specialists, were also tested for the presence of SIBO by the glucose hydrogen (H2)/methane (CH4) breath test (HMBT). A detailed anamnesis was carried out about the history of H. pylori infection, eradication therapies, proton pump inhibitor intake, and comorbidities. In total, 36/109 (33.0%) patients had a positive H. pylori(13)C-UBT, and 35/109 (32.1%) patients had a positive glucose HMBT, the latter being indicative of SIBO. Interestingly, individuals with a positive H. pylori(13)C-UBT were significantly more often associated with a positive glucose HMBT (p=0.002). Cohen's κ measuring agreement between the (13)C-UBT and the glucose HMBT was 0.31 (confidence intervals: 0.12-0.50) (p=0.001). Altogether, 19 of 54 (35.2%) patients, who had completed up to four eradication therapies, were diagnosed with SIBO by HMBT. H. pylori infection was found to be significantly associated with the presence of SIBO as determined by functional breath testing. In addition, SIBO rates appeared to have increased after completed eradication therapies. However, further longitudinal studies are warranted to fully elucidate the relationship and treatment modalities of coincident H. pylori infection and SIBO. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  10. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technicians fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  11. Medical Issues: Breathing

    MedlinePlus

    ... About Us News Facebook Twitter YouTube Learn About SMA About SMA Types of SMA Causes & Diagnosis Genetics Testing Carriers What Diagnosis Means ... Care Packages Information Packets Equipment Pool Living With SMA Medical Issues Palliative Breathing Orthopedics Nutrition Equipment Daily ...

  12. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technician Rod Ostgrard helps fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  13. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technician John Thompson helps fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  14. Lactose tolerance tests

    MedlinePlus

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen in the air you breathe out. ...

  15. Do urea breath test (UBT) referrals for Helicobacter pylori testing match the clinical guidelines in primary care practice? A prospective observational study.

    PubMed

    Noya, Horowitz; Anat, Beit-Or; Moshe, Leshno; Gennady, Polishchouk; Zamir, Halpern; Menachem, Moshkowitz

    2008-10-01

    Various international guidelines recommend the use of non-endoscopic tests [such as urea breath test (UBT)] for the evaluation of dyspeptic patients, unless endoscopy is clinically indicated. To assess adherence with guidelines for UBT referrals among primary care doctors in Israel. Patients referred by primary care doctors to an open-access UBT service were included in the study. Prior to the test, all patients were administered with a short questionnaire regarding their symptoms, previous and concomitant medications including previous Helicobacter pylori eradication. The study sample consisted of 209 patients, aged 18-94 years, M/F = 74/135. The UBT was judged to be appropriate in 94 (45%) subjects, inappropriate in 93 (44.5%) subjects and appropriate but avoidable in 22 (10.5%) subjects, most of them asymptomatic patients following anti H. pylori treatment. The inappropriate indications include 38 (18%) patients with suspected gastro-oesophageal reflux disease symptoms and 21 (10%) dyspeptic patients aged 45 years or more. Nearly 45% percent of UBT referrals in primary care practice were inappropriate, and a significant number of dyspeptic patients should have been referred to endoscopy. These findings show a substantial non-compliance with guidelines for H. pylori testing among primary care doctors.

  16. Comparison of encapsulated versus nonencapsulated (14) C-urea breath test for the detection of Helicobacter pylori infection: a scintigraphy study.

    PubMed

    Pathak, Chander M; Kaur, Balwinder; Bhasin, Deepak K; Mittal, Bhagwant R; Sharma, Sarika; Khanduja, Krishan L; Aggarwal, Lalit; Rana, Surinder S

    2014-04-01

    (14) C-urea breath test ((14) C-UBT) is considered as "gold standard" for detection of active gastric H. pylori infection. However, till date no comparative study using encapsulated and non-encapsulated (14) C-UBT protocols has been conducted in same subjects in identical conditions. We monitored gastric fate of capsule containing (14) C-urea with real time display and compared sensitivities of these protocols at different time points of breath collection. Non-encapsulated (14) C-UBT was performed using 74 kBq of (14) C-urea in 100 dyspeptic patients by collecting breath samples at 10, 15 and 20 minutes. Thereafter, within 2 days a gelatin capsule containing (14) C-urea along with 6.0 MBq of (99m) Tc-diethylene triamine penta-acetic acid was administered to each patient for real time display of capsule movement and its fate in gastrointestinal tract by gamma camera. Simultaneously, breath samples were collected for (14) CO2 measurement during image acquisition. Employing non-encapsulated (14) C-UBT, 74 out of 100 dyspeptic patients were found to be H. pylori positive. Discordant (14) C-UBT results were obtained in 4/74 (5.4%) cases using these two protocols. By employing encapsulated and nonencapsulated (14) C-UBT protocols, sensitivities of (14) C-UBT were found to be 90.5 versus 98.6% at 10 and 91.8 versus 97.2% at 15 minutes respectively; while these were 94.6 versus 100, 90.7 versus 98.6 and 83.7 versus 93.2% considering any one, two or all three positive values respectively. Incomplete/non-resolution of (14) C-urea capsule in stomach during the phase of breath collections appears to decrease sensitivity of encapsulated (14) C-UBT as compared to nonencapsulated protocol for detection of H. pylori infection. © 2013 John Wiley & Sons Ltd.

  17. A Stable Isotope Breath Test with a Standard Meal for Abnormal Gastric Emptying of Solids in the Clinic and in Research

    PubMed Central

    Szarka, Lawrence A.; Camilleri, Michael; Vella, Adrian; Burton, Duane; Baxter, Kari; Simonson, Julie; Zinsmeister, Alan R.

    2009-01-01

    Aim To validate a [13C]-Spirulina platensis gastric emptying (GE) breath test (GEBT) with a standardized meal. Methods 38 healthy volunteers and 129 patients with clinically suspected delayed GE underwent measurements at 45, 90, 120, 150, 180, and 240 min after a 238 kcal meal labeled test with 100 mg [13C]-Spirulina platensis, and 0.5 mCi 99mTc. We established normal ranges for scintigraphy with this test meal, intra- and inter-individual coefficients of variation (COV) and the ability of the [13C] GEBT breath kPCD (percent dose excreted *1000) values to predict scintigraphic t½, and to categorize GE as delayed, normal or accelerated. Results In health, the 10th and 90th percentile of t½ for scintigraphic GE with this meal are 52 and 86 min; intra-individual COV for scintigraphy and the GEBT were respectively 31% and 27% at 45 min; 17% and 21% at 90 min; 13% and 16% at 120 min; 10% and 13% at 150 min; and 8% and 12% at 180 min. Inter-individual COVs at each time for the [13C] GEBT and scintigraphy were typically ~ 1–4% lower than intra-individual COVs. Individual breath samples at 45, 150 and 180 min predicted GE category: at 80% specificity, 45 and 180 min samples combined were 93% sensitive to identify accelerated GE; 150 and 180 min combined were 89% sensitive for delayed GE. Conclusions [13C]-Spirulina platensis GEBT is as reproducible as scintigraphy; imprecision with both tests reflects physiologic variation. Using 4 breath samples, this method with an off-the-shelf meal is valid to assess GE in clinic and in research. PMID:18406670

  18. Photosynthetic Gas Exchange and Discrimination against 13CO2 and C18O16O in Tobacco Plants Modified by an Antisense Construct to Have Low Chloroplastic Carbonic Anhydrase.

    PubMed Central

    Williams, T. G.; Flanagan, L. B.; Coleman, J. R.

    1996-01-01

    The physiological role of chloroplastic carbonic anhydrase (CA) was examined by antisense suppression of chloroplastic CA (on average 8% of wild type) in Nicotiana tabacum. Photosynthetic gas-exchange characteristics of low-CA and wild-type plants were measured concurrently with short-term, on-line stable isotope discrimination at varying vapor pressure deficit (VPD) and light intensity. Low-CA and wild-type plants were indistinguishable in the responses of assimilation, transpiration, stomatal conductance, and intercellular CO2 concentration to changing VPD or light intensity. At saturating light intensity, low-CA plants had lower discrimination against 13CO2 than wild-type plants by 1.2 to 1.8[per mille (thousand) sign]. Consequently, tissue of the low-CA plants was higher in 13C than the control plants. It was calculated that low-CA plants had chloroplast CO2 concentrations 13 to 22 [mu]mol mol-1 lower than wild-type plants. Discrimination against C18O16O in low-CA plants was 20% of that of the wild type, confirming a role of chloroplastic CA in the mechanism of discrimination against C18O16O ([delta]C18O16O). As VPD increased, stomatal closure caused a reduction in chloroplastic C02 concentration, and since VPD and chloroplastic CO2 concentration act in opposing directions on [delta]C18O16O, no effect of VPD was seen on [delta]C18O16O. PMID:12226395

  19. Quantifying Protein Synthesis and Degradation in Arabidopsis by Dynamic 13CO2 Labeling and Analysis of Enrichment in Individual Amino Acids in Their Free Pools and in Protein1[OPEN

    PubMed Central

    Fernie, Alisdair R.; Stitt, Mark

    2015-01-01

    Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied 13CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%–4% d−1), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark. PMID:25810096

  20. Photosynthetic Gas Exchange and Discrimination against 13CO2 and C18O16O in Tobacco Plants Modified by an Antisense Construct to Have Low Chloroplastic Carbonic Anhydrase.

    PubMed

    Williams, T. G.; Flanagan, L. B.; Coleman, J. R.

    1996-09-01

    The physiological role of chloroplastic carbonic anhydrase (CA) was examined by antisense suppression of chloroplastic CA (on average 8% of wild type) in Nicotiana tabacum. Photosynthetic gas-exchange characteristics of low-CA and wild-type plants were measured concurrently with short-term, on-line stable isotope discrimination at varying vapor pressure deficit (VPD) and light intensity. Low-CA and wild-type plants were indistinguishable in the responses of assimilation, transpiration, stomatal conductance, and intercellular CO2 concentration to changing VPD or light intensity. At saturating light intensity, low-CA plants had lower discrimination against 13CO2 than wild-type plants by 1.2 to 1.8[per mille (thousand) sign]. Consequently, tissue of the low-CA plants was higher in 13C than the control plants. It was calculated that low-CA plants had chloroplast CO2 concentrations 13 to 22 [mu]mol mol-1 lower than wild-type plants. Discrimination against C18O16O in low-CA plants was 20% of that of the wild type, confirming a role of chloroplastic CA in the mechanism of discrimination against C18O16O ([delta]C18O16O). As VPD increased, stomatal closure caused a reduction in chloroplastic C02 concentration, and since VPD and chloroplastic CO2 concentration act in opposing directions on [delta]C18O16O, no effect of VPD was seen on [delta]C18O16O.

  1. An anthropomorphic breathing phantom of the thorax for testing new motion mitigation techniques for pencil beam scanning proton therapy.

    PubMed

    Perrin, R L; Zakova, M; Peroni, M; Bernatowicz, K; Bikis, C; Knopf, A K; Safai, S; Fernandez-Carmona, P; Tscharner, N; Weber, D C; Parkel, T C; Lomax, A J

    2017-03-21

    Motion-induced range changes and incorrectly placed dose spots strongly affect the quality of pencil-beam-scanned (PBS) proton therapy, especially in thoracic tumour sites, where density changes are large. Thus motion-mitigation techniques are necessary, which must be validated in a realistic patient-like geometry. We report on the development and characterisation of a dynamic, anthropomorphic, thorax phantom that can realistically mimic thoracic motions and anatomical features for verifications of proton and photon 4D treatments. The presented phantom is of an average thorax size, and consists of inflatable, deformable lungs surrounded by a skeleton and skin. A mobile 'tumour' is embedded in the lungs in which dosimetry devices (such as radiochromic films) can be inserted. Motion of the tumour and deformation of the thorax is controlled via a custom made pump system driving air into and out of the lungs. Comprehensive commissioning tests have been performed to evaluate the mechanical performance of the phantom, its visibility on CT and MR imaging and its feasibility for dosimetric validation of 4D proton treatments. The phantom performed well on both regular and irregular pre-programmed breathing curves, reaching peak-to-peak amplitudes in the tumour of  <20 mm. Some hysteresis in the inflation versus deflation phases was seen. All materials were clearly visualised in CT scans, and all, except the bone and lung components, were MRI visible. Radiochromic film measurements in the phantom showed that imaging for repositioning was required (as for a patient treatment). Dosimetry was feasible with Gamma Index agreements (4%/4 mm) between film dose and planned dose  >90% in the central planes of the target. The results of this study demonstrate that this anthropomorphic thorax phantom is suitable for imaging and dosimetric studies in a thoracic geometry closely-matched to lung cancer patients under realistic motion conditions.

  2. The caffeine breath test and caffeine urinary metabolite ratios in the Michigan cohort exposed to polybrominated biphenyls: a preliminary study.

    PubMed Central

    Lambert, G H; Schoeller, D A; Humphrey, H E; Kotake, A N; Lietz, H; Campbell, M; Kalow, W; Spielberg, S P; Budd, M

    1990-01-01

    A field biochemical epidemiology study was conducted using the Michigan cohort consisting of 51 rural residents exposed to polybrominated biphenyls (PBB). The study had three major objectives: a) to determine the serum half-life of the major PBB congener, hexabromobiphenyl (HBB), in the human, b) to determine if the PBB-exposed subjects had elevated cytochrome P-450I function as determined by the caffeine breath test (CBT) and the caffeine urinary metabolite ratio (CMR), and c) to determine the applicability of the CBT and CMR in field studies. PBB serum levels were detected in 36 of the 51 PBB-exposed subjects. The serum half-life of HBB was determined by comparing the current serum HBB values to the subject's previous serum values obtained 5 to 8 years earlier. The median HBB half-life was 12 years (range 4-97 years). The CBT and CMR were elevated in the subjects exposed to PBBs as compared to the values obtained from urban nonsmokers and were similar to those found in adults who smoke. A gender effect was seen in the PBB-exposed subjects, the median CBT and CMR values of the females being lower than the values of males. There was a correlation between the CBT and the HBB serum values (r2 = 0.2, p = 0.01) but not between CMR and HBB serum values. The CBT and CMR were easily conducted in the field and appear to be useful metabolic probes of cytochrome P-450I activity in human environmental toxicology. PMID:1965165

  3. Determination of rifaximin treatment period according to lactulose breath test values in nonconstipated irritable bowel syndrome subjects.

    PubMed

    Bae, Suhyun; Lee, Kwang Jae; Kim, Young-Sang; Kim, Kyu-Nam

    2015-06-01

    Small intestinal bacterial overgrowth (SIBO) can partly explain irritable bowel syndrome (IBS), and rifaximin has been observed to improve abdominal symptoms in nonconstipated IBS patients. However, there are few reports on the association of the rifaximin treatment periods with the results of a lactulose breath test (LBT). Therefore, we performed a retrospective review of patient charts to investigate the relation between the rifaximin treatment periods with LBT results in nonconstipated IBS patients. We also evaluated the time to achieve a symptomatic improvement in the IBS patients as compared to the changes in the LBT. We reviewed the charts for patients who showed IBS symptoms with documented positive results for LBT during their initial visit and who had a follow-up LBT after treatment with rifaximin. The LBT values were compared to the subjects' symptom scores. A total of 102 subjects had a follow-up LBT to assess LBT normalization. The subjects were divided into groups according to treatment periods of 4 weeks (n = 36), 8 weeks (n = 43), and 12 weeks (n = 23). The groups with a longer treatment exhibited an increase in the hydrogen gas value at 90 min and its sum during 90 min at the initial LBT. There were significant differences in hydrogen gas value at 90 min and in its sum during 90 min at the initial LBT between the groups treated for 4 and 12 weeks. The most significant treatment response was observed during the first 4 weeks for all treatment groups. Symptomatic improvement occurred earlier than LBT normalization in the treatment period over 4 weeks. The results indicate that different rifaximin treatment periods are needed in accordance with LBT levels to effectively eradicate SIBO.

  4. An anthropomorphic breathing phantom of the thorax for testing new motion mitigation techniques for pencil beam scanning proton therapy

    NASA Astrophysics Data System (ADS)

    Perrin, R. L.; Zakova, M.; Peroni, M.; Bernatowicz, K.; Bikis, C.; Knopf, A. K.; Safai, S.; Fernandez-Carmona, P.; Tscharner, N.; Weber, D. C.; Parkel, T. C.; Lomax, A. J.

    2017-03-01

    Motion-induced range changes and incorrectly placed dose spots strongly affect the quality of pencil-beam-scanned (PBS) proton therapy, especially in thoracic tumour sites, where density changes are large. Thus motion-mitigation techniques are necessary, which must be validated in a realistic patient-like geometry. We report on the development and characterisation of a dynamic, anthropomorphic, thorax phantom that can realistically mimic thoracic motions and anatomical features for verifications of proton and photon 4D treatments. The presented phantom is of an average thorax size, and consists of inflatable, deformable lungs surrounded by a skeleton and skin. A mobile ‘tumour’ is embedded in the lungs in which dosimetry devices (such as radiochromic films) can be inserted. Motion of the tumour and deformation of the thorax is controlled via a custom made pump system driving air into and out of the lungs. Comprehensive commissioning tests have been performed to evaluate the mechanical performance of the phantom, its visibility on CT and MR imaging and its feasibility for dosimetric validation of 4D proton treatments. The phantom performed well on both regular and irregular pre-programmed breathing curves, reaching peak-to-peak amplitudes in the tumour of  <20 mm. Some hysteresis in the inflation versus deflation phases was seen. All materials were clearly visualised in CT scans, and all, except the bone and lung components, were MRI visible. Radiochromic film measurements in the phantom showed that imaging for repositioning was required (as for a patient treatment). Dosimetry was feasible with Gamma Index agreements (4%/4 mm) between film dose and planned dose  >90% in the central planes of the target. The results of this study demonstrate that this anthropomorphic thorax phantom is suitable for imaging and dosimetric studies in a thoracic geometry closely-matched to lung cancer patients under realistic motion conditions.

  5. Sex difference in the effects of alcohol on gastric emptying in healthy volunteers: a study using the (13)C breath test.

    PubMed

    Horikoshi, Miyuki; Funakoshi, Akihiro; Miyasaka, Kyoko; Sekime, Ayako

    2013-01-01

    Several studies on alcohol and gastric emptying using the (13)C breath test showed that alcohol consumption delayed gastric emptying of meals in healthy male subjects. However, they did not employ female subjects, and the retention time of alcoholic beverages in the stomach has not been examined, yet. We examined the retention time (= gastric emptying rate) of alcoholic beverages in the stomach in healthy male and female subjects. We also examined whether the congeners (nonalcoholic components) of red wine have any effect on gastric emptying. The retention time of 60 mL of red wine, vodka, congeners of red wine, or mineral water, was measured using a (13)C labeled acetic acid breath test. In male subjects, the retention time of wine and vodka was significantly longer than that of congeners and mineral water. In female subjects, although the (13)C content in the breath was slightly but significantly decreased by wine and congeners, but not by vodka, and the parameters for gastric emptying did not differ significantly among the 4 drinks. That is, alcohol hardly influenced the retention time in female subjects. In conclusion, there are sex differences in the gastric emptying rate of alcohol.

  6. Short-term carbon dynamics in a temperate heathland upon six years of exposure to elevated CO2 concentration, drought and warming: Evidence from an in-situ 13CO2 pulse-chase experiment

    NASA Astrophysics Data System (ADS)

    Ambus, P.; Reinsch, S.; Sárossy, Z.; Egsgaard, H.; Jakobsen, I.; Michelsen, A.; Schmidt, I.; Nielsen, P.

    2013-12-01

    An in-situ 13CO2 pulse-labeling experiment was carried out in a temperate heathland (8 oC MAT, 610 mm MAP) to study the impact on short-term carbon (C) allocation as affected by elevated CO2 concentration (+120 ppm), prolonged summer droughts (ca. -43 mm) and warming (+1 oC). The study was carried out six years after the climate treatments were initiated and took place in the early growing season in May in vegetation dominated by grasses, mainly Deschampsia flexuosa. Newly assimilated C (13C from the pulse-label) was traced into vegetation, soil and soil microorganisms and belowground respiration 1, 2 and 8 days after pulse-labeling. The importance of the microbial community in C utilization was investigated using 13C enrichment patterns in different microbial functional groups on the basis of phospholipid fatty acid (PLFA) profiles. Climate treatments did not affect microorganism abundance in soil or rhizosphere fractions in terms of total PLFA-C concentration. Elevated CO2 significantly reduced the abundance of gram-negative bacteria (17:0cy), but did not affect the abundance of decomposers (fungi and actinomycetes) in rhizosphere fractions. Drought favored the bacterial community in rhizosphere fractions whereas warming reduced the abundance of gram-negative bacteria (19:0cy) and changed the actinomycetes community (10Me16:0, 10Me18:0). Fastest and highest utilization of recently assimilated C was observed in rhizosphere associated gram-negative bacteria followed by gram-positive bacteria. The utilization of recently assimilated C by the microbial community was faster under elevated CO2 conditions compared to ambient. The 13C assimilation by green plant tissue and translocation to roots was significantly reduced by the extended summer drought. Under elevated CO2 conditions we observed an increased amount of 13C in the litter fraction. The assimilation of 13C by vegetation was not changed when the climate factors were applied in combination. The total amount of

  7. Validation of the String Test for the Recovery of Helicobacter pylori from Gastric Secretions and Correlation of Its Results with Urea Breath Test Results, Serology, and Gastric pH Levels

    PubMed Central

    Torres, Javier; Camorlinga, Margarita; Pérez-Peréz, Guillermo; Gonzalez, Gerardo; Muñoz, Onofre

    2001-01-01

    The efficacy of the string culture test to isolate Helicobacter pylori from gastric secretions of 28 volunteers was studied. With the urea breath test (UBT) as the “gold standard,” the string culture test showed a sensitivity of 75% and a specificity of 100%. The results of string culture did not correlate with the UBT results, with serum antibody levels, or with the pH levels of gastric secretions. PMID:11283108

  8. Psychometric evaluation of the COPD assessment test: data from the BREATHE study in the Middle East and North Africa region.

    PubMed

    Jones, Paul W; Shahrour, Naem; Nejjari, Chakib; Lahlou, Aicha; Doble, Adam; Rashid, Nauman; El Hasnaoui, Abdelkader

    2012-12-01

    The objective of this study was to assess the validity and performance of the Arabic and Turkish versions of the COPD Assessment Test (CAT) for evaluating the severity and impact of COPD symptoms. The data were obtained from the BREATHE study in the Middle East and North Africa region, a large general population survey of COPD conducted in ten countries of the region (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), using a standardised methodology. A total of 62,086 subjects were screened, of whom a random sample of 5,681 subjects were administered the CAT by telephone. 5,639 evaluable questionnaires were recovered, representing a completion rate of 99%. In addition, the CAT was administered to an additional 833 subjects fulfilling the epidemiological diagnostic criteria for COPD. Mean scores in the general population were 6.99 ± 6.91 for the Arabic version and 9.88 ± 9.04 for the Turkish version. In patients with COPD, mean scores were 16.2 ± 9.1 and 20.9 ± 10.2 respectively. Scores were consistently higher in smokers than in non-smokers. In the general population, the proportion of respondents fulfilling criteria for COPD rose with higher CAT scores, and particularly above the 80th percentile, where 63% of COPD cases were to be found. This suggests that the CAT may be useful as a case-finding tool in the general population. In the COPD population, healthcare resource consumption rose linearly with CAT score above a threshold score of twenty, arguing in favour of the good criterion validity of the CAT. The internal consistency of the CAT was high (Cronbach's α 0.85 for the Arabic and 0.86 for the Turkish versions) and the factorial structure was unidimensional. In conclusion, this study performed in Arabic and Turkish speaking populations confirms the utility and validity of the CAT as a simple tool to collect data on the severity and impact of COPD symptoms, and suggests that it may potentially be

  9. Rapid shallow breathing

    MedlinePlus

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking ...

  10. Breathing and Relaxation

    MedlinePlus

    ... Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make an Appointment Ask a Question ... level is often dependent on his or her breathing pattern. Therefore, people with chronic lung conditions may ...

  11. Deep breathing after surgery

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000440.htm Deep breathing after surgery To use the sharing features on ... way to do so is by doing deep breathing exercises. Deep breathing keeps your lungs well-inflated ...

  12. Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, (13)C-urea breath test, and serology.

    PubMed

    Choi, Jeongmin; Kim, Chung Hyeon; Kim, Donghee; Chung, Su Jin; Song, Ji Hyun; Kang, Jung Mook; Yang, Jong In; Park, Min Jung; Kim, Young Sun; Yim, Jeong Yoon; Lim, Seon Hee; Kim, Joo Sung; Jung, Hyun Chae; Song, In Sung

    2011-06-01

    This study aimed to evaluate the efficacy of a new polyclonal enzyme immunoassay for the detection of Helicobacter pylori (H. pylori) antigen in stool by determination of the optimal cut-off value in the screening population. A consecutive 515 patients undergoing a routine health check-up were prospectively enrolled. H. pylori infection was defined if at least two of four tests (histology, rapid urease test, (13)C-urea breath test, and serology) were positive. A stool antigen test (EZ-STEP H. pylori) was performed for the detection of H. pylori. The optimal cut-off value was determined by the receiver-operator characteristic curve. The diagnostic performance of each test was evaluated with regard to the histological diagnosis of atrophic gastritis (AG)/intestinal metaplasia (IM), degree of AG/IM, and old age. Sensitivity, specificity, positive and negative predictive values, and accuracy of the stool antigen test were 93.1%, 94.6%, 95.1%, 92.3%, and 93.8%, respectively. The sensitivity of histology, rapid urease test, and the (13)C-urea breath test ranged from 89.1% to 97.6%, and their specificity was > 98%, while serology had high sensitivity, but low specificity. The accuracy of the stool antigen test was comparable to that of other methods (93.6-95.9%), whereas it was higher than that of serology. The stool antigen test still showed good diagnostic performance in the setting of progression of AG/IM and in patients over 40 years. The performance of a new stool antigen test was comparable to that of other methods in the diagnosis of H. pylori infection for the screening population, even with the presence of AG/IM. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

  13. Utility of the wireless motility capsule and lactulose breath testing in the evaluation of patients with Parkinson's disease who present with functional gastrointestinal symptoms

    PubMed Central

    Su, Andrew; Gandhy, Rita; Barlow, Carrolee; Triadafilopoulos, George

    2017-01-01

    Background The aetiology and origin of gastrointestinal symptoms in Parkinson's disease (PD) remains poorly understood. Gastroparesis, small bowel transit delay and bacterial overgrowth may, individually or collectively, play a role. Aims In patients with PD and functional gastrointestinal symptoms, we aimed to determine the utility of the wireless motility capsule and lactulose breath tests in further defining their symptoms' aetiology. Methods In this retrospective cohort study, consecutive patients with PD and functional gastrointestinal symptoms underwent clinical assessment, as well as wireless motility capsule and lactulose breath testing using standard protocols. Results We studied 65 patients with PD and various gastrointestinal symptoms. 35% exhibited gastroparesis by the wireless motility capsule study, 20% small bowel transit delay, while 8% had combined transit abnormalities, suggestive of overlapping gastric and small bowel dysmotility. Small bowel bacterial overgrowth was seen in 34% of cases. Symptoms of abdominal pain, regurgitation, bloating, nausea, vomiting, belching and weight loss could not distinguish between patients with or without gastroparesis, although bloating was significantly more prominent (p<0.001) overall and specifically more so in patients with slow small bowel transit (p<0.01). There was no relationship between delayed small bowel transit time and bacterial overgrowth (p=0.5); PD scores and duration were not correlated with either the transit findings or small bowel bacterial overgrowth. Conclusions Functional gastrointestinal symptoms in patients with PD may reflect gastroparesis, small bowel transit delay or both, suggesting motor and/or autonomic dysfunction, and may be associated with small bowel bacterial overgrowth. The wireless motility capsule and lactulose breath testing are non-invasive and useful in the assessment of these patients. PMID:28321329

  14. Is Hydrogen Breath Test with Lactulose Feasible for Measuring Gastrocecal Transit in Critically Ill Children? Pilot Study about Modification of the Technique.

    PubMed

    López, J; Sánchez, C; Fernández, S N; González, R; Solana, M J; Urbano, J; Tolín, M; López-Herce, J

    2017-01-01

    Introduction. Gastrocecal transit time (GCTT) can be measured by exhaled hydrogen after lactulose intake (lactulose-eH2 test). The objectives were to assess whether it is possible to carry out this test in critically ill children with and without mechanical ventilation (MV) and to analyze whether the results are consistent with clinical findings. Methods. Patients admitted to the Pediatric Intensive Care Unit (PICU) for more than 3 days were included. Those with gastrointestinal disease prior to admission were excluded. A modified technique to obtain eH2 from the ventilator tubes was performed. Results. Sixteen patients (37.5% boys) with a median age of 19 (5-86.5) months were included. Five patients (31.2%) were breathing spontaneously but lactulose-eH2 test could not be performed while it could be performed successfully in the 11 patients with MV. Seven patients (63.3%) did not show an eH2 peak. The other 4 showed a median time of 130 min (78.7-278.7 min) from lactulose intake to a 10 ppm eH2 peak. Children with an eH2 peak had intestinal movements earlier [6.5 (1.5-38.5) versus 44 (24-72) hours p = 0.545]. Conclusion. Although the designed adaption is useful for collecting breath samples, lactulose-eH2 test may not be useful for measuring GCTT in critically ill children.

  15. Analysis of Exhaled Breath for Disease Detection

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  16. Analysis of exhaled breath for disease detection.

    PubMed

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-01-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  17. Collection of breath for hydrogen estimation.

    PubMed

    Gardiner, A J; Tarlow, M J; Sutherland, I T; Sammons, H G

    1981-02-01

    The breath hydrogen test is used in gastroenterological investigation, particularly for sugar malabsorption, transit time, and the investigation of small-bowel bacterial overgrowth. Several methods of collecting breath from infants and children for hydrogen assay have been described. Four such techniques (postnasal catheter, nasal prong, Rahn-Otis end-tidal sampler, and modification of a party toy--the 'Wiggins's blowout') were compared with breath collection using the Haldane-Priestley tube. Multiple sampling of breath from 3 adults was performed after initial lactulose loads to increase breath hydrogen excretion. The variability between the different assay techniques was less than the inherent variability of repeated breath hydrogen assays using the same technique. Each technique is therefore adequate for breath hydrogen collection; we recommend the Rahn-Otis end-tidal sampler in young infants and children, and the Haldane-Priestley tube in older children, since these were most acceptable to the children and their parents.

  18. A monitoring of breathing using a hetero-core optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Akita, S.; Seki, A.; Watanabe, K.

    2011-04-01

    A monitoring human breath has been seen as an important source of factor for vital status for emergency medical service. The monitoring of breathing has been tested and evaluated in a possible breath condition of a person to be monitored. A hetero-core optical fiber humidity sensor was developed for in order to monitor relative humidity in a medial mask. Elements for determent breath condition were extracted from the light intensity changing at some human breath condition, which were Breath depth, Breath cycle, Breath time and Check breathing. It is found that the elements had differences relative to normal breathing.

  19. Small intestinal bacterial overgrowth as an uncommon cause of false positive lactose hydrogen breath test among patients with diarrhea-predominant irritable bowel syndrome in Asia.

    PubMed

    Wang, Yilin; Xiong, Lishou; Gong, Xiaorong; Li, Weimin; Zhang, Xiangsong; Chen, Minhu

    2015-06-01

    It has been reported that small intestinal bacterial overgrowth (SIBO) may lead to false positive diagnoses of lactose malabsorption (LM) in irritable bowel syndrome patients. The aim of this study was to determine the influence of SIBO on lactose hydrogen breath test (HBT) results in these patients. Diarrhea-predominant irritable bowel syndrome patients with abnormal lactose HBTs ingested a test meal containing (99m) Tc and lactose. The location of the test meal and the breath levels of hydrogen were recorded simultaneously by scintigraphic scanning and lactose HBT, respectively. The increase in hydrogen concentration was not considered to be caused by SIBO if ≥ 10% of (99m) Tc accumulated in the cecal region at the time or before of abnormal lactose HBT. LM was present in 84% (31/37) of irritable bowel syndrome patients. Twenty of these patients agreed to measurement of oro-cecal transit time. Only three patients (15%) with abnormal lactose HBT might have had SIBO. The median oro-cecal transit time between LM and lactose intolerance patients were 75 min and 45 min, respectively (Z=2.545, P=0.011). Most of irritable bowel syndrome patients with an abnormal lactose HBT had LM. SIBO had little impact on the interpretation of lactose HBTs. The patients with lactose intolerance had faster small intestinal transit than LM patients. © 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  20. Method validation and application of a liquid chromatography-tandem mass spectrometry method for drugs of abuse testing in exhaled breath.

    PubMed

    Stephanson, Niclas; Sandqvist, Sören; Lambert, Marjan Shafaati; Beck, Olof

    2015-03-15

    A mass spectrometric method for drugs of abuse testing in exhaled breath employing a sampling device collecting aerosol particles was developed and applied in routine use. Analytes covered were amphetamine, methamphetamine, 6-acetylmorphine, morphine, cocaine, benzoylecgonine, diazepam, oxazepam and tetrahydrocannabinol. The method involved eluting drugs from the collection filter with methanol, quantification using deuterated analogs as internal standards, reversed phase chromatography with gradient elution, positive electrospray ionization and monitoring of two product ions per analyte in selected reaction monitoring mode. The measuring range was 6.0-1000pg/filter. The intra- and inter-assay imprecision expressed as the coefficient of variation was less than 7%. Influence from matrix was noted for most compounds but was compensated for the use of co-eluting internal standards. The LLOQ was 6.0pg/filter with intra-assay CV <5% and accuracy within 99-102% for all analytes. No chromatographic interference was observed in 20 negative control samples. The LC-MS/MS method was successfully applied for measuring drugs in unknown samples collected for the purpose of drug testing. Among the 1096 analyzed samples analytical findings were made in breath in 39 cases (3.6%). Most frequently found substances were the following: amphetamine (25 cases) methamphetamine (10 cases), THC (8 cases), cocaine (4 cases), benzoylecgonine (2 cases) and diazepam (2 cases). In conclusion, a fully validated and robust screening method suitable for the routine measurement of drugs of abuse in exhaled breath with a simple procedure for specimen collection and sample preparation was successfully developed.

  1. SU-D-BRE-01: A Realistic Breathing Phantom of the Thorax for Testing New Motion Mitigation Techniques with Scanning Proton Therapy

    SciTech Connect

    Perrin, R; Peroni, M; Bernatowicz, K; Zakova, M; Knopf, A; Safai, S; Parkel, T

    2014-06-01

    Purpose: A prototype breathing phantom (named LuCa) has been developed which simulates the anatomy and motion of a patient thorax.In this work, we describe the results of the first commissioning tests with LuCa. Methods: The phantom provides a close representation of the human thorax. The lungs,contained within a tissue-equivalent ribcage and skin,are made from a polymer foam,which is inflated and deflated using a custommade ventilator. A tumor is simulated using a wooden ball with cutplanes for placing GafChromic films. The ventilator,controlled with Labview software,simulates a full range of breathing motion types.Commissioning tests were performed to assess its performance using imaging (CT and radiographic) and film dosimetry as follows:i)maximum Tumor excursion at acceptable pressure ranges, ii)tumor Motion repeatability between breathing periods,iii)reproducibility between measurement days,iv)tumor-to-surface motion correlation and v)reproducibility of film positioning in phantom. Results: The phantom can generate repeatable motion patterns with sin{sup 4},sin,breath-hold (tumor amplitude repeatability <0.5mm over 10min),aswell as patient-specific motion types. Maximum excursions of the tumor are 20mm and 14mm for the large and small tumor inserts respectively. Amplitude reproducibility (Coefficient of Variation) averaged at 16% for the workable pressure range over 2 months. Good correlation between tumor and surface motion was found with R{sup 2}=0.92. Reproducibility of film positioning within the thorax was within 0.9mm, and maximum 3° error from the coronal plane. Film measurements revealed that the film repositioning error yields relative errors in the mean dose over the planned target volume (PTV) of up to 2.5% and 4.5% for films at the center and on the edge of the PTV respectively. Conclusion: Commissioning tests have shown that the LuCa phantom can produce tumor motion with excellent repeatability. However,a poorer performance in reproducibility of

  2. Inside anesthesia breathing circuits: time to reach a set sevoflurane concentration in toddlers and newborns: simulation using a test lung.

    PubMed

    Kern, Delphine; Larcher, Claire; Basset, Bertrand; Alacoque, Xavier; Fesseau, Rose; Samii, Kamran; Minville, Vincent; Fourcade, Olivier

    2012-08-01

    We measured the time it takes to reach the desired inspired anesthetic concentration using the Primus (Drägerwerk, AG, Lübeck, Germany) and the Avance (GE Datex-Ohmeda, Munich, Germany) anesthesia machines with toddler and newborn ventilation settings. The time to reach 95% of inspired target sevoflurane concentration was measured during wash-in from 0 to 6 vol% sevoflurane and during wash-out from 6 to 0 vol% with fresh gas flows equal to 1 and 2 times the minute ventilation. The Avance was faster than the Primus (65 seconds [95% confidence interval (CI): 55 to 78] vs 310 seconds [95% CI: 261 to 359]) at 1.5 L/min fresh gas flow, tidal volume of 50 mL, and 30 breaths/min. Times were shorter by the same magnitude at higher fresh gas flows and higher minute ventilation rates. The effect of doubling fresh gas flow was variable and less than expected. The Primus is slower during newborn than toddler ventilation, whereas the Avance's response time was the same for newborn and toddler ventilation. Our data confirm that the time to reach the target-inspired anesthetic concentration depends on breathing circuit volume, fresh gas flow, and minute ventilation.

  3. Breathing exercises: influence on breathing patterns and thoracoabdominal motion in healthy subjects

    PubMed Central

    Vieira, Danielle S. R.; Mendes, Liliane P. S.; Elmiro, Nathália S.; Velloso, Marcelo; Britto, Raquel R.; Parreira, Verônica F.

    2014-01-01

    BACKGROUND: The mechanisms underlying breathing exercises have not been fully elucidated. OBJECTIVES: To evaluate the impact of four on breathing exercises (diaphragmatic breathing, inspiratory sighs, sustained maximal inspiration and intercostal exercise) the on breathing pattern and thoracoabdominal motion in healthy subjects. METHOD: Fifteen subjects of both sexes, aged 23±1.5 years old and with normal pulmonary function tests, participated in the study. The subjects were evaluated using the optoelectronic plethysmography system in a supine position with a trunk inclination of 45° during quiet breathing and the breathing exercises. The order of the breathing exercises was randomized. Statistical analysis was performed by the Friedman test and an ANOVA for repeated measures with one factor (breathing exercises), followed by preplanned contrasts and Bonferroni correction. A p<0.005 value was considered significant. RESULTS: All breathing exercises significantly increased the tidal volume of the chest wall (Vcw) and reduced the respiratory rate (RR) in comparison to quiet breathing. The diaphragmatic breathing exercise was responsible for the lowest Vcw, the lowest contribution of the rib cage, and the highest contribution of the abdomen. The sustained maximal inspiration exercise promoted greater reduction in RR compared to the diaphragmatic and intercostal exercises. Inspiratory sighs and intercostal exercises were responsible for the highest values of minute ventilation. Thoracoabdominal asynchrony variables increased significantly during diaphragmatic breathing. CONCLUSIONS: The results showed that the breathing exercises investigated in this study produced modifications in the breathing pattern (e.g., increase in tidal volume and decrease in RR) as well as in thoracoabdominal motion (e.g., increase in abdominal contribution during diaphragmatic breathing), among others. PMID:25590447

  4. Nutritional status, fecal elastase-1, and 13C-labeled mixed triglyceride breath test in the long-term after pancreaticoduodenectomy.

    PubMed

    Muniz, Cinara Knychala; dos Santos, José Sebastião; Pfrimer, Karina; Ferrioli, Eduardo; Kemp, Rafael; Marchini, Júlio Sérgio; Cunha, Selma Freire

    2014-04-01

    This study aimed to compare the body composition, dietary intake and serum levels of vitamins and minerals, and exocrine pancreatic function in patients late after pancreaticoduodenectomy (PD) and healthy subjects. Fifteen patients (PD group) who had undergone PD over 1 year before the study and 15 health volunteers (control group) were included in the study. All volunteers underwent dietary intake evaluation, body composition, laboratory data, exocrine pancreatic function by elastase-1, and carbon (C )-labeled triglycerides in breath tests. The PD group subjects also underwent upper gastrointestinal endoscopy and small intestinal bacterial overgrowth analysis. Nutrient intake was adequate, and there were no differences in body mass index and mineral serum levels between the groups. The PD group showed lower serum levels of retinol, α-tocopherol, and ascorbic acid. Small intestinal bacterial overgrowth occurred in 39% of the patients. Fecal elastase-1 was lower in the PD group. The PD group had a higher C peak time; the cumulative label C recovery in 7 hours was similar in both groups. Fecal elastase-1 decreased, and the excretion of C in breath was similar to healthy controls. Although the data point toward an adaptation in the absorptive capacity of fats, A, C, and E hypovitaminosis indicate that some absorptive insufficiency persists late after PD.

  5. Comparison of inulin and lactulose as reference standards in the breath hydrogen test assessment of carbohydrate malabsorption in patients with chronic pancreatic exocrine insufficiency.

    PubMed

    Owira, P M O; Young, G O; Winter, T A

    2005-06-01

    Although often used as a reference standard in the breath hydrogen test (BHT), lactulose fermentation produces more hydrogen, compared to starch, and may therefore not be ideal. This study compares inulin with lactulose as reference standard in the study of carbohydrate malabsorption. Seventeen patients with malabsorption due to chronic pancreatitis and 15 normal controls were studied. Following overnight fasts, BHTs were performed after ingesting 10 g lactulose, 10 g inulin, and 200 g (16 g highly resistant starch) maize meal. Lactulose fermentation produced significantly more hydrogen than inulin in patients with malabsorption (97 +/- 20 vs 45 +/- 22 ppm x hr; P < 0.05) and controls (43 +/- 18 vs 21 +/- 10 ppm x hr; P < 0.05). Patients produced more hydrogen than controls with both standards (lactulose, 97 +/- 20 vs 43 +/- 18 ppm x hr, P < 0.05; inulin 45 +/- 22 vs 21 +/- 10 ppm x hrs; P < 0.05), suggesting adaptation of the colonic flora. Calculated CHO malabsorption was 2.5 +/- 0.8 vs 5.2 +/- 3.8 g with lactulose and 5.2 +/- 3.1 vs 11.2 +/- 9.6 g with inulin as standards in controls and patients, respectively (P < 0.05). Lactulose produces more breath hydrogen than inulin. Calculation of CHO malabsorption using these standards is therefore not comparable.

  6. Breath ammonia measurement in Helicobacter pylori infection.

    PubMed

    Kearney, David J; Hubbard, Todd; Putnam, David

    2002-11-01

    Our aim was to define the utility of breath ammonia measurement in assessing Helicobacter pylori infection. Volunteers breathed into a device containing three fiberoptic NH3 sensors at baseline and after ingesting 300 mg of urea. Breath ammonia levels were compared to the [14C]urea breath test. Thirteen subjects were tested. Before urea ingestion, H. pylori-positive subjects had significantly lower breath ammonia levels than negative subjects (mean +/- SD, 0.04 ppm +/- 0.09 vs 0.49 ppm +/- 0.24, P = 0.002) and had a significantly greater increases in breath ammonia after urea ingestion (range 198-1,494% vs 6-98%). One H. pylori-positive subject underwent treatment and breath ammonia levels shifted from the pattern seen in positive subjects to that seen in negative subjects. In conclusion, breath ammonia measurement for H. Pylori-positive and negative subjects showed distinct patterns. Breath ammonia measurement may be feasible as a diagnostic test for H. pylori.

  7. Is Hydrogen Breath Test with Lactulose Feasible for Measuring Gastrocecal Transit in Critically Ill Children? Pilot Study about Modification of the Technique

    PubMed Central

    Sánchez, C.; González, R.; Solana, M. J.; Urbano, J.; Tolín, M.

    2017-01-01

    Introduction. Gastrocecal transit time (GCTT) can be measured by exhaled hydrogen after lactulose intake (lactulose-eH2 test). The objectives were to assess whether it is possible to carry out this test in critically ill children with and without mechanical ventilation (MV) and to analyze whether the results are consistent with clinical findings. Methods. Patients admitted to the Pediatric Intensive Care Unit (PICU) for more than 3 days were included. Those with gastrointestinal disease prior to admission were excluded. A modified technique to obtain eH2 from the ventilator tubes was performed. Results. Sixteen patients (37.5% boys) with a median age of 19 (5–86.5) months were included. Five patients (31.2%) were breathing spontaneously but lactulose-eH2 test could not be performed while it could be performed successfully in the 11 patients with MV. Seven patients (63.3%) did not show an eH2 peak. The other 4 showed a median time of 130 min (78.7–278.7 min) from lactulose intake to a 10 ppm eH2 peak. Children with an eH2 peak had intestinal movements earlier [6.5 (1.5–38.5) versus 44 (24–72) hours p = 0.545]. Conclusion. Although the designed adaption is useful for collecting breath samples, lactulose-eH2 test may not be useful for measuring GCTT in critically ill children. PMID:28246601

  8. Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

    2016-11-01

    Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (<1 min) and on site breath acetone measurement can be used for diabetic screening and management under a specifically controlled condition.

  9. [Relationship between abnormal swallowing and mouth breathing].

    PubMed

    Wang, Meng-wu; Li, Hong-fa; Wang, Qiu-rui; Xu, Hao; He, Jing-nan

    2013-12-01

    To investigate the relationship between abnormal swallowing and mouth breathing. Thirty-eight patients with abnormal swallowing and 38 patients with normal swallowing were selected. All patients presented with no airway constriction. The age range of the patients was 11-14 years old. The number of patients with mouth breathing was calculated. Statistical analysis (χ(2) test) was performed. The number of patients with mouth breathing in the abnormal swallowing group (17, 45%) was significantly higher than that in the normal swallowing group (5, 13%) (χ(2) = 9.212, P = 0.002). Abnormal swallowing was related to mouth breathing.

  10. Breathing difficulty - lying down

    MedlinePlus

    Waking at night short of breath; Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea ... obstructive pulmonary disease (COPD) Cor pulmonale Heart failure ... conditions that lead to it) Panic disorder Sleep apnea Snoring

  11. Shortness of Breath

    MedlinePlus

    ... Wheezing Worsening of pre-existing shortness of breath Self-care To help keep chronic shortness of breath ... JA, et al. Dyspnea. In: Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, Pa.: Saunders ...

  12. Minimizing Shortness of Breath

    MedlinePlus

    ... postures and exposure to environmental irritants. Pursed-Lip Breathing One focus of occupational therapy is to teach ... the accessory muscles and manage respiratory symptoms. Monitor Breathing During an activity, it is important to pause ...

  13. Pursed lip breathing (image)

    MedlinePlus

    ... were going to whistle or blow out a candle. Breathe out (exhale) slowly through your lips for 4 or ... were going to whistle or blow out a candle. Breathe out (exhale) slowly through your lips for 4 or ...

  14. [Quantification of the drug-metabolizing enzyme system in liver diseases: a comparison between antipyrine saliva clearance and the aminopyrine breath test].

    PubMed

    von Mandach, U; Jost, G; Preisig, R

    1985-05-11

    The metabolic activity of the hepatic cytochrome P450 system was studied in 53 ambulatory subjects. 18 of these were cirrhotics and 23 had non-cirrhotic liver disease, documented by biopsy, serologic, ultrasound or computerized tomography findings, and characterized by quantitative liver function tests, such as galactose elimination capacity and indocyanine green fractional clearance. For comparison, 12 normal control subjects were also included. All subjects were given 10 mg/kg body weight antipyrine and saliva concentrations determined with an HPLC-method at 24 and 48 hours after dosing. Antipyrine saliva clearance (ASC) was calculated according to a two-point method (Cl1), and compared with a one-point method (Cl2) using the 24 h sample only. These subjects also underwent an aminopyrine breath test (ABT), breath samples being collected at regular intervals during 60 minutes following injection of a tracer dose of 1.5 muCi (14C-dimethylamino)antipyrine. Cl1 and Cl2 correlated strongly (r = 0.93). On the basis of smaller variations (particularly in control subjects), better definition of disease severity and convenience and time saving, Cl2 is to be preferred. Comparison of Cl2 with ABT showed that both procedures apparently quantify overlapping enzymatic activities. However, the relationship between Cl2 and ABT values, albeit highly significant (r = 0.72), suggests that only about half of the variables are subject to the same determinant. In addition, a positive intercept of the regression line extrapolated to the Cl2 axis points to quantitatively important extrahepatic breakdown of antipyrine. The results suggest that, in view of the wide variation in normal values (presumably in part influenced by exogenous pollutants), ASC only provides an approximation of hepatic metabolic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. The 13C-Glucose Breath Test for Insulin Resistance Assessment in Adolescents: Comparison with Fasting and Post-Glucose Stimulus Surrogate Markers of Insulin Resistance

    PubMed Central

    Maldonado-Hernández, Jorge; Martínez-Basila, Azucena; Salas-Fernández, Alejandra; Navarro-Betancourt, José R.; Piña-Aguero, Mónica I.; Bernabe-García, Mariela

    2016-01-01

    Objective: To evaluate the use of the 13C-glucose breath test (13C-GBT) for insulin resistance (IR) detection in adolescents through comparison with fasting and post-glucose stimulus surrogates. Methods: One hundred thirty-three adolescents aged between 10 and 16 years received an oral glucose load of 1.75 g per kg of body weight dissolved in 150 mL of water followed by an oral dose of 1.5 mg/kg of U-13C-Glucose, without a specific maximum dose. Blood samples were drawn at baseline and 120 minutes, while breath samples were obtained at baseline and at 30, 60, 90, 120, 150, and 180 minutes. The 13C-GBT was compared to homeostasis model assessment (HOMA) IR (≥p95 adjusted by gender and age), fasting plasma insulin (≥p90 adjusted by gender and Tanner stage), results of 2-h oral glucose tolerance test (OGTT), insulin levels (≥65 μU/mL) in order to determine the optimal cut-off point for IR diagnosis. Results: 13C-GBT data, expressed as adjusted cumulative percentage of oxidized dose (A% OD), correlated inversely with fasting and post-load IR surrogates. Sexual development alters A% OD results, therefore individuals were stratified into pubescent and post-pubescent. The optimal cut-off point for the 13C-GBT in pubescent individuals was 16.3% (sensitivity=82.8% & specificity=60.6%) and 13.0% in post-pubescents (sensitivity=87.5% & specificity=63.6%), when compared to fasting plasma insulin. Similar results were observed against HOMA and 2-h OGTT insulin. Conclusion: The 13C-GBT is a practical and non-invasive method to screen for IR in adolescents with reasonable sensitivity and specificity. PMID:27354200

  16. The non-invasive 13C-methionine breath test detects hepatic mitochondrial dysfunction as a marker of disease activity in non-alcoholic steatohepatitis

    PubMed Central

    2011-01-01

    Introduction Mitochondrial dysfunction plays a central role in the general pathogenesis of non-alcoholic fatty liver disease (NAFLD), increasing the risk of developing steatosis and subsequent hepatocellular inflammation. We aimed to assess hepatic mitochondrial function by a non-invasive 13C-methionine breath test (MeBT) in patients with histologically proven NAFLD. Methods 118 NAFLD-patients and 18 healthy controls were examined by MeBT. Liver biopsy specimens were evaluated according to the NASH scoring system. Results Higher grades of NASH activity and fibrosis were independently associated with a significant decrease in cumulative 13C-exhalation (expressed as cPDR(%)). cPDR1.5h was markedly declined in patients with NASH and NASH cirrhosis compared to patients with simple steatosis or borderline diagnosis (cPDR1.5h: 3.24 ± 1.12% and 1.32 ± 0.94% vs. 6.36 ± 0.56% and 4.80 ± 0.88% respectively; p < 0.001). 13C-exhalation further declined in the presence of advanced fibrosis which was correlated with NASH activity (r = 0.36). The area under the ROC curve (AUROC) for NASH diagnosis was estimated to be 0.87 in the total cohort and 0.83 in patients with no or mild fibrosis (F0-1). Conclusion The 13C-methionine breath test indicates mitochondrial dysfunction in non-alcoholic fatty liver disease and predicts higher stages of disease activity. It may, therefore, be a valuable diagnostic addition for longitudinal monitoring of hepatic (mitochondrial) function in non-alcoholic fatty liver disease. PMID:21810560

  17. Prevalence of Helicobacter Pylori Infection in School and Pre-School Aged Children with C-14 Urea Breath Test and the Association with Familial and Environmental Factors

    PubMed Central

    Çınar, Alev; Sadıç, Murat; İkbal Atılgan, Hasan; Baskın, Aylin; Koca, Gökhan; Demirel, Koray; Korkmaz, Meliha

    2015-01-01

    Objective: To investigate the prevalence of Helicobacter pylori (Hp) infection in pre-school and school age children with C-14 urea breath test, and to explore its association with age and socioeconomic factors in Turkey. Methods: Hp infection status was determined by using Urea Breath Test (UBT). Patients who had previous gastric surgery, Hp eradication treatment or equivocal UBT results were excluded. A questionnaire was administered to elicit information on gender, age, ABO/Rh blood group type, presence of gastric disease in the family, domestic animal in the household, and treatment for idiopathic Iron Deficiency Anemia (IDA). Results: This retrospective study included 500 pediatric patients (179 boys, 321 girls, mean age 10.7±4.3 years) of whom 62 (12.4%) were aged ≤6 years and 438 (87.6%) were aged 7 to 16 years. Helicobacter pylori (Hp) was positive in 245 (49%) cases. In the pre-school age group, 21/62 cases (34%) had positive UBT while in the school age group 224/438 children (51%) had positive UBT. A family history of dyspepsia and pet ownership were not associated with Hp positivity. Hp positive 76 (29.8%) children were on IDA treatment but this was not statistically significant. Conclusion: The Hp infection positivity rate was 49% in the pediatric age study group. The positivity rate was significantly lower at preschool age than school age, and it increased with age. There was no association with gender, ABO/Rh blood groups, presence of domestic pets, IDA, or history of gastric disease in the family. PMID:26316471

  18. NASA firefighters breathing system program report

    NASA Technical Reports Server (NTRS)

    Wood, W. B.

    1977-01-01

    Because of the rising incidence of respiratory injury to firefighters, local governments expressed the need for improved breathing apparatus. A review of the NASA firefighters breathing system program, including concept definition, design, development, regulatory agency approval, in-house testing, and program conclusion is presented.

  19. What Causes Bad Breath?

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness What Causes Bad Breath? KidsHealth > For Teens > What Causes Bad Breath? A A A en español ¿Qué es lo que provoca el mal aliento? Bad breath, or halitosis , can be a major problem, ...

  20. Non-invasive panel tests for gastrointestinal motility monitoring within the MARS-500 Project

    PubMed Central

    Roda, Aldo; Mirasoli, Mara; Guardigli, Massimo; Simoni, Patrizia; Festi, Davide; Afonin, Boris; Vasilyeva, Galina

    2013-01-01

    AIM: To develop an integrated approach for monitoring gastrointestinal motility and inflammation state suitable for application in long-term spaceflights. METHODS: Breath tests based on the oral administration of 13C-labeled or hydrogen-producing substrates followed by the detection of their metabolites (13CO2 or H2) in breath were used to measure gastrointestinal motility parameters during the 520-d spaceflight ground simulation within the MARS-500 Project. In particular, the gastric emptying rates of solid and liquid contents were evaluated by 13C-octanoic acid and 13C-acetate breath tests, respectively, whereas the orocecal transit time was assessed by an inulin H2-breath test, which was performed simultaneously with the 13C-octanoic acid breath test. A ready-to-eat, standardized pre-packaged muffin containing 100 mg of 13C-octanoic acid was used in the 13C-octanoic acid breath test to avoid the extemporaneous preparation of solid meals. In addition, a cassette-type lateral flow immunoassay was employed to detect fecal calprotectin, a biomarker of intestinal inflammation. Because no items could be introduced into the simulator during the experiment, all materials and instrumentation required for test performance during the entire mission simulation had to be provided at the beginning of the experiment. RESULTS: The experiments planned during the simulation of a manned flight to Mars could be successfully performed by the crewmembers without any external assistance. No evident alterations (i.e., increasing or decreasing trends) in the gastric emptying rates were detected using the 13C-breath tests during the mission simulation, as the gastric emptying half-times were in the range of those reported for healthy subjects. In contrast to the 13C-breath tests, the results of the inulin H2-breath test were difficult to interpret because of the high variability of the H2 concentration in the breath samples, even within the same subject. This variability suggested that

  1. Fiber-enhanced Raman multigas spectroscopy: a versatile tool for environmental gas sensing and breath analysis.

    PubMed

    Hanf, Stefan; Keiner, Robert; Yan, Di; Popp, Jürgen; Frosch, Torsten

    2014-06-03

    Versatile multigas analysis bears high potential for environmental sensing of climate relevant gases and noninvasive early stage diagnosis of disease states in human breath. In this contribution, a fiber-enhanced Raman spectroscopic (FERS) analysis of a suite of climate relevant atmospheric gases is presented, which allowed for reliable quantification of CH4, CO2, and N2O alongside N2 and O2 with just one single measurement. A highly improved analytical sensitivity was achieved, down to a sub-parts per million limit of detection with a high dynamic range of 6 orders of magnitude and within a second measurement time. The high potential of FERS for the detection of disease markers was demonstrated with the analysis of 27 nL of exhaled human breath. The natural isotopes (13)CO2 and (14)N(15)N were quantified at low levels, simultaneously with the major breath components N2, O2, and (12)CO2. The natural abundances of (13)CO2 and (14)N(15)N were experimentally quantified in very good agreement to theoretical values. A fiber adapter assembly and gas filling setup was designed for rapid and automated analysis of multigas compositions and their fluctuations within seconds and without the need for optical readjustment of the sensor arrangement. On the basis of the abilities of such miniaturized FERS system, we expect high potential for the diagnosis of clinically administered (13)C-labeled CO2 in human breath and also foresee high impact for disease detection via biologically vital nitrogen compounds.

  2. Is absorption of irrigation fluid a problem in Thulium laser vaporization of the prostate? A prospective investigation using the expired breath ethanol test.

    PubMed

    Mordasini, Livio; Abt, Dominik; Müllhaupt, Gautier; Engeler, Daniel S; Lüthi, Andreas; Schmid, Hans-Peter; Schwab, Christoph

    2015-04-24

    Benign prostatic hyperplasia (BPH) is a prevalent entity in elderly men. If medical treatment fails, monopolar transurethral resection of the prostate (TUR-P) is still considered as the standard treatment. The proportion of high-risk patients with cardiac comorbidities increases and TUR-P goes along with a relevant perioperative risk. Especially large volume influx of irrigation fluid and transurethral resection syndrome (TUR syndrome) represent serious threats to these patients. Using isotonic saline as irrigation fluid like in transurethral laser vaporization (TUV-P), TUR syndrome can be prevented. However, no prospective trial has ever assessed occurrence or extent of irrigation fluid absorption in Thulium Laser TUV-P. This is a single-center prospective trial, investigating, if absorption of irrigation fluid occurs during Thulium Laser TUV-P by expired breath ethanol test. The expired breath ethanol technique is an established method of investigating intraoperative absorption of irrigation fluid: A tracer amount of ethanol is added to the irrigation fluid and the absorption of irrigation fluid can be calculated by measuring the expiratory ethanol concentrations of the patient with an alcohol breathalyzer. Fifty consecutive patients undergoing TUV-P at our tertiary referral center are included into the trial. Absorption volume of irrigation fluid during Thulium Laser TUV-P is defined as primary endpoint. Pre- to postoperative changes in bladder diaries, biochemical and hematological laboratory findings, duration of operation and standardized questionnaires are assessed as secondary outcome measures. The aim of this study is to assess the safety of Thulium Laser TUV-P in regard to absorption of irrigation fluid.

  3. The relationship of normal body temperature, end-expired breath temperature, and BAC/BrAC ratio in 98 physically fit human test subjects.

    PubMed

    Cowan, J Mack; Burris, James M; Hughes, James R; Cunningham, Margaret P

    2010-06-01

    The relationship between normal body temperature, end-expired breath temperature, and blood alcohol concentration (BAC)/breath alcohol concentration (BrAC) ratio was studied in 98 subjects (84 men, 14 women). Subjects consumed alcohol sufficient to produce a BrAC of at least 0.06 g/210 L 45-75 min after drinking. Breath samples were analyzed using an Intoxilyzer 8000 specially equipped to measure breath temperature. Venous blood samples and body temperatures were then taken. The mean body temperature of the men (36.6 degrees C) was lower than the women (37.0 degrees C); however, their mean breath temperatures were virtually identical (men: 34.5 degrees C; women: 34.6 degrees C). The BAC exceeded the BrAC for every subject. BAC/BrAC ratios were calculated from the BAC and BrAC analytical results. There was no difference in the BAC/BrAC ratios for men (1:2379) and women (1:2385). The correlation between BAC and BrAC was high (r = 0.938, p < 0.0001), whereas the correlations between body temperature and end-expired breath temperature, body temperature and BAC/BrAC ratio, and breath temperature and BAC/BrAC ratio were much lower. Neither normal body temperature nor end-expired breath temperature was strongly associated with BAC/BrAC ratio.

  4. Clinical value of radionuclide small intestine transit time measurement combined with lactulose hydrogen breath test for the diagnosis of bacterial overgrowth in irritable bowel syndrome.

    PubMed

    Ning, Yanli; Lou, Cen; Huang, Zhongke; Chen, Dongfang; Huang, Huacheng; Chen, Liang; Zhang, Bucheng; Dai, Ning; Zhao, Jianmin; Zhen, Xia

    2016-01-01

    Small intestine bacterial overgrowth (SIBO) may be a pathogenetic factor for irritable bowel syndrome (IBS). This syndrome cannot be explained by structural abnormalities and has no specific diagnostic laboratory tests or biomarkers. We studied quantitatively and semi-quantitatively, using lactulose hydrogen breath test (LHBT), small intestinal transit time (SITT) (99m)technetium-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in order to examine the mobility of small intestine as an indication of bacterial overgrowth in patients. Eighty nine consecutive patients who met Rome criteria for IBS were retrospectively studied. According to the diagnostic criteria, all patients were divided into two groups: the SIBO group and the non-SIBO group. The tracer was a mixture of 10g lactulose, 37MBq (99m)Tc-DTPA and 100mL water. The patient drank the whole mixture during 1min and the SITT study started immediately. The SITT and the LHBT followed every 15min for up to 3h after emptying the urine bladder. Spearman's rank correlation was applied to assess the correlation of oro-cecum transit time (OCTT) between imaging and LHBT. The semi-quantitative index between the SIBO group and the non-SIBO group was analyzed with Wilcoxon's rank sum test. If there was significant group difference, the receiver operating characteristic (ROC) curve was used. P<0.05 was considered significant. The median and inter-quartile range for OCTT for the LHBT (OCTT-L) for all patients was 90min and 60min, respectively, and 75min and 45min for OCTT for the SITT study (OCTT-i). There was positive correlation between OCTT-L and OCTT-i at the 0.05 level (R=0.290, P=0.000). There were no differences in OCTT-i and in the rate of radioactivity (counts of regions of interest ROI) over the abdomen between the SIBO group and the non-SIBO group (P=0.116 and 0.290). There were significant differences in the temporal association of the hydrogen (H2) value with OCTT-i (H2-i) and OCTT-L between the two groups (P

  5. Finger dexterity and visual discrimination following two yoga breathing practices

    PubMed Central

    Telles, Shirley; Singh, Nilkamal; Balkrishna, Acharya

    2012-01-01

    Background: Practicing yoga has been shown to improve motor functions and attention. Though attention is required for fine motor and discrimination tasks, the effect of yoga breathing techniques on fine motor skills and visual discrimination has not been assessed. Aim: To study the effect of yoga breathing techniques on finger dexterity and visual discrimination. Materials and Methods: The present study consisted of one hundred and forty subjects who had enrolled for stress management. They were randomly divided into two groups, one group practiced high frequency yoga breathing while the other group practiced breath awareness. High frequency yoga breathing (kapalabhati, breath rate 1.0 Hz) and breath awareness are two yoga practices which improve attention. The immediate effect of high frequency yoga breathing and breath awareness (i) were assessed on the performance on the O′Connor finger dexterity task and (ii) (in) a shape and size discrimination task. Results: There was a significant improvement in the finger dexterity task by 19% after kapalabhati and 9% after breath awareness (P<0.001 in both cases, repeated measures ANOVA and post-hoc analyses). There was a significant reduction (P<0.001) in error (41% after kapalabhati and 21% after breath awareness) as well as time taken to complete the shape and size discrimination test (15% after kapalabhati and 15% after breath awareness; P<0.001) was also observed. Conclusion: Both kapalabahati and breath awareness can improve fine motor skills and visual discrimination, with a greater magnitude of change after kapalabhati. PMID:22346064

  6. Finger dexterity and visual discrimination following two yoga breathing practices.

    PubMed

    Telles, Shirley; Singh, Nilkamal; Balkrishna, Acharya

    2012-01-01

    Practicing yoga has been shown to improve motor functions and attention. Though attention is required for fine motor and discrimination tasks, the effect of yoga breathing techniques on fine motor skills and visual discrimination has not been assessed. To study the effect of yoga breathing techniques on finger dexterity and visual discrimination. The present study consisted of one hundred and forty subjects who had enrolled for stress management. They were randomly divided into two groups, one group practiced high frequency yoga breathing while the other group practiced breath awareness. High frequency yoga breathing (kapalabhati, breath rate 1.0 Hz) and breath awareness are two yoga practices which improve attention. The immediate effect of high frequency yoga breathing and breath awareness (i) were assessed on the performance on the O'Connor finger dexterity task and (ii) (in) a shape and size discrimination task. There was a significant improvement in the finger dexterity task by 19% after kapalabhati and 9% after breath awareness (P<0.001 in both cases, repeated measures ANOVA and post-hoc analyses). There was a significant reduction (P<0.001) in error (41% after kapalabhati and 21% after breath awareness) as well as time taken to complete the shape and size discrimination test (15% after kapalabhati and 15% after breath awareness; P<0.001) was also observed. Both kapalabahati and breath awareness can improve fine motor skills and visual discrimination, with a greater magnitude of change after kapalabhati.

  7. Chemical sensors for breath gas analysis: the latest developments at the Breath Analysis Summit 2013.

    PubMed

    Tisch, Ulrike; Haick, Hossam

    2014-06-01

    Profiling the body chemistry by means of volatile organic compounds (VOCs) in the breath opens exciting new avenues in medical diagnostics. Gas sensors could provide ideal platforms for realizing portable, hand-held breath testing devices in the near future. This review summarizes the latest developments and applications in the field of chemical sensors for diagnostic breath testing that were presented at the Breath Analysis Summit 2013 in Wallerfangen, Germany. Considerable progress has been made towards clinically applicable breath testing devices, especially by utilizing chemo-sensitive nanomaterials. Examples of several specialized breath testing applications are presented that are either based on stand-alone nanomaterial-based sensors being highly sensitive and specific to individual breath compounds over others, or on combinations of several highly specific sensors, or on experimental nanomaterial-based sensors arrays. Other interesting approaches include the adaption of a commercially available MOx-based sensor array to indirect breath testing applications, using a sample pre-concentration method, and the development of compact integrated GC-sensor systems. The recent trend towards device integration has led to the development of fully integrated prototypes of point-of-care devices. We describe and compare the performance of several prototypes that are based on different sensing technologies and evaluate their potential as low-cost and readily available next-generation medical devices.

  8. Episodic breathing in alligators: role of sensory feedback.

    PubMed

    Douse, M A; Mitchell, G S

    1992-01-01

    The episodic breathing pattern in many reptiles consists of two or more clustered breaths separated by variable non-ventilatory periods. This pattern is commonly postulated to result from oscillations in lung and/or blood PO2 or PCO2 via chemoreceptor feedback. We tested this hypothesis by monitoring breathing pattern in: (1) awake, undisturbed alligators and (2) sedated alligators (approx. 25 mg/kg pentobarbital, i.p.; 3 days prior to data collection). In sedated alligators, measurements were made: (1) before and after bilateral cervical vagotomy, a procedure that removes peripheral arterial chemoreceptors, CO2-sensitive intrapulmonary chemoreceptors and pulmonary stretch receptors (n = 6); and (2) during unidirectional ventilation (UDV) at high flow rates (greater than 2 L/min), thereby minimizing oscillations in lung and blood PO2 and PCO2 (n = 6). Measurements on sedated alligators were made at 30 and 20 degrees C in each of these conditions. In awake, undisturbed alligators, breathing was typically episodic with 2-7 breaths/cluster, although the pattern was easily altered (increased breaths/cluster) by even seemingly minor disturbances. In sedated alligators, episodic breathing was still evident after vagotomy, but only at increased inspired CO2; at 5% CO2 four of six alligators exhibited episodic breathing consisting of 2-3 breaths/cluster interspersed with occasional single breaths. An episodic breathing pattern was also evident during UDV; at low levels of CO2, 2-4 breaths/cluster interspersed with occasional single breaths were evident in four alligators, while two had 6-8 breaths/cluster. Increasing CO2 in the UDV gas stream generally increased the number of breaths/cluster. After vagotomy, all six alligators could manifest an episodic breathing pattern during UDV in at least one CO2 condition (greater than 2 breaths/cluster interspersed with occasional single breaths). The episodic breathing pattern was very labile, sometimes changing to single breaths

  9. Urease-positive bacteria in the stomach induce a false-positive reaction in a urea breath test for diagnosis of Helicobacter pylori infection.

    PubMed

    Osaki, Takako; Mabe, Katsuhiro; Hanawa, Tomoko; Kamiya, Shigeru

    2008-07-01

    This study investigated the influence of urease-positive non-Helicobacter pylori bacteria on the results of a urea breath test (UBT) to evaluate the diagnostic utility of a UBT using film-coated [(13)C]urea tablets. The UBT was performed in 102 patients treated with a proton pump inhibitor and antibiotics for the eradication of H. pylori. Urease-producing bacteria other than H. pylori were isolated and identified from the oral cavity and stomach. In 4/102 patients, the UBT gave false-positive results. These false-positive results were found to be caused by the presence of urease-positive bacteria in the oral cavity and stomach. Five bacterial species with urease activity (Proteus mirabilis, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae and Staphylococcus aureus) were subsequently isolated from the oral cavity and/or stomach. As there was no correlation between the in vitro urease activity of urease-positive non-H. pylori bacteria and the UBT value, and all of the patients with a false-positive UBT result were suffering from atrophic gastritis, it is possible that the false-positive results in the UBT were a result of colonization of urease-positive bacteria and gastric hypochlorhydric conditions. Thus, for the diagnosis of H. pylori infection using a UBT, the influence of stomach bacteria must be considered when interpreting the results.

  10. Prevalence and risk factors of helicobacter pylori in Turkey: a nationally-representative, cross-sectional, screening with the 13C-Urea breath test

    PubMed Central

    2013-01-01

    Background Helicobacter pylori is an important global pathogen infecting approximately 50% of the world’s population. This study was undertaken in order to estimate the prevalence rate of Helicobacter pylori infections among adults living in Turkey and to investigate the associated risk factors. Method This study was a nationally representative cross sectional survey, using weighted multistage stratified cluster sampling. All individuals aged ≥18 years in the selected households were invited to participate in the survey. Ninety two percent (n = 2382) of the households in 55 cities participated; 4622 individuals from these households were tested with the 13C-Urea breath test. Helicobacter pylori prevalence and associated factors were analysed by the t test, chi square and multiple logistic regression with SPSS11.0. Results The weighted overall prevalence was 82.5% (95% CI: 81.0-84.2) and was higher in men. It was lowest in the South which has the major fruit growing areas of the country. The factors included in the final model were sex, age, education, marital status, type of insurance (social security), residential region, alcohol use, smoking, drinking water source. While education was the only significant factor for women, residential region, housing tenure, smoking and alcohol use were significant for men in models by sex. Conclusion In Turkey, Helicobacter pylori prevalence was found to be very high. Individuals who were women, elderly adults, single, had a high educational level, were living in the fruit growing region, had social security from Emekli Sandigi, were drinking bottled water, non smokers and regular alcohol consumers, were under less risk of Helicobacter pylori infection than others. PMID:24359515

  11. Control of breathing in the echidna (Tachyglossus aculeatus) during hibernation.

    PubMed

    Nicol, Stewart; Andersen, Niels A

    2003-12-01

    Resting non-hibernating echidnas are characterised by low metabolic rates, but also have a very low respiratory frequency and a variable respiratory minute volume, often resulting in low levels of arterial O(2) and high CO(2). As the echidna lies at one physiological extreme among the hibernators, in terms of its large size and low metabolism and ventilatory requirement when not hibernating, a study of control of breathing during hibernation in echidnas should provide a useful test of the generality of various models. We used non-invasive techniques to study breathing patterns and the control of ventilation in 6 echidnas. Hibernating echidnas (T(b) range 7-10 degrees C) showed episodic breathing with bursts of breaths (average 36+/-16 breaths in 24+/-5 min) followed by a period of apnea (76+/-17 min) then a series (8+/-4) of slow breaths at 14+/-1 min intervals leading up to the next burst. Increasing CO(2) levels in the inspired air increased the number of breaths in a burst, eventually leading to continuous breathing. Inter burst breaths were controlled by O(2): hypoxia increased inter burst breaths, and decreased burst length, while hyperoxia abolished inter burst breaths and increased the apneic period. Overall, while CO(2) was a strong respiratory stimulus in hibernating echidnas, O(2) had little effect on total ventilation, but did have a strong effect on the breathing pattern.

  12. Breathing-metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Breathing-metabolic simulator was developed to be used for evaluation of life support equipment. Apparatus simulates human breathing rate and controls temperature and humidity of exhaled air as well as its chemical composition. All functions are designed to correspond to various degrees of human response.

  13. From breathing to respiration.

    PubMed

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  14. What Controls Your Breathing?

    MedlinePlus

    ... Explore How the Lungs Work What Are... The Respiratory System What Happens When You Breathe What Controls Your Breathing Lung Diseases & Conditions Clinical Trials Links Related Topics Asthma Bronchitis COPD How the Heart Works Respiratory Failure Send a link to NHLBI to someone ...

  15. Isotope-labelled urea to test colon drug delivery devices in vivo: principles, calculations and interpretations.

    PubMed

    Maurer, Marina J M; Schellekens, Reinout C A; Wutzke, Klaus D; Stellaard, Frans

    2013-01-01

    This paper describes various methodological aspects that were encountered during the development of a system to monitor the in vivo behaviour of a newly developed colon delivery device that enables oral drug treatment of inflammatory bowel diseases. [(13)C]urea was chosen as the marker substance. Release of [(13)C]urea in the ileocolonic region is proven by the exhalation of (13)CO2 in breath due to bacterial fermentation of [(13)C]urea. The (13)CO2 exhalation kinetics allows the calculation of a lag time as marker for delay of release, a pulse time as marker for the speed of drug release and the fraction of the dose that is fermented. To determine the total bioavailability, also the fraction of the dose absorbed from the intestine must be quantified. Initially, this was done by calculating the time-dependent [(13)C]urea appearance in the body urea pool via measurement of (13)C abundance and concentration of plasma urea. Thereafter, a new methodology was successfully developed to obtain the bioavailability data by measurement of the urinary excretion rate of [(13)C]urea. These techniques required two experimental days, one to test the coated device, another to test the uncoated device to obtain reference values